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71,397,747 | https://en.wikipedia.org/wiki/Alloy%20601 | Alloy 601 is a nickel alloy, mostly made up of nickel and chromium, with small amounts of aluminium, silicon, copper and manganese. This creates a number of desirable properties including good high temperature strength, corrosion resistance under oxidizing conditions and it retains ductility after long service exposure. It is often used in various types of engineering equipment which require heat resistance and corrosion resistance.
Composition
Properties
Alloy 601 can also be identified by the UNS Number N06601. It shares similar properties to Alloy 600, but is more resistant to high-temperature oxidation due to the addition of aluminium. The combination of heat resistance and oxidation resistance means it is often used in the thermal processing industry for applications such as radiant tubes. It is also commonly used in high-temperature applications in the aerospace industry, such as gas turbine blades, combustion can-liners and jet engine igniters.
References
Nickel–chromium alloys | Alloy 601 | [
"Chemistry"
] | 189 | [
"Alloys",
"Alloy stubs"
] |
71,398,112 | https://en.wikipedia.org/wiki/Leucocoprinus%20velutipes | Leucocoprinus velutipes is a species of mushroom producing fungus in the family Agaricaceae.
Taxonomy
It was first described in 1932 by the Belgian mycologist Maurice Beeli and was illustrated in 1936. Beeli had classified the species as Lepiota flavescens apparently without realising that this name had already been used by the American mycologist Andrew Price Morgan in 1907. Thus Beeli's classification was illegitimate.
In 1977 it was reclassified as Leucocoprinus velutipes by the Belgian mycologist Paul Heinemann.
Morgans's Lepiota flavescens was ultimately reclassified as Leucocoprinus flavescens in 1981.
Description
Leucocoprinus velutipes is a dapperling mushroom with thin whitish-yellow flesh.
Cap: 5-6cm wide, campanulate expanding to convex or flattened with a pronounced umbo. The surface is whitish-yellow with reddish-brown woolly scales (tomentose) on the umbo whilst the rest of the cap is speckled with fine brown scales. The cap edges have slight striations which do not extend far across the cap. Stem: 7-9cm tall and 3-4mm thick tapering gradually from the base which is 10mm wide. The interior is slightly hollow and the surface is brownish-yellow with a brown shaggy coating from top to bottom. The membranous, ascending stem ring is yellowish with some brown details. Gills: Free, moderately crowded (5mm), yellowish-white. Spore print: White. Spores: Ellipsoid. 8.3-9.8 x 6.0-6.8 μm. The whole mushroom drys dark brown.
Habitat and distribution
L. velutipes is scarcely recorded and little known. Beeli and Heinemann's studies were based on specimens found in Zaire, Central Africa (now the Democratic Republic of the Congo) where they were found near the town of Binga growing in groups on dead wood.
GBIF only contains one recorded observation of this species.
Etymology
The specific epithet velutipes derives from the Latin velutinus meaning velvety and stipes meaning stem. and refers to the shaggy stem this mushroom.
References
Leucocoprinus
Fungi described in 1932
Fungi of Africa
Taxa named by Paul Heinemann
Taxa named by Maurice Beeli
Fungus species | Leucocoprinus velutipes | [
"Biology"
] | 495 | [
"Fungi",
"Fungus species"
] |
71,398,145 | https://en.wikipedia.org/wiki/Uroxite | Uroxite is an oxalate mineral first discovered as part of the Carbon Mineral Challenge. It is the first discovered uranium-containing organic mineral.
References
Minerals
Organic minerals
Monoclinic minerals
Oxalate minerals
Minerals described in 2020 | Uroxite | [
"Chemistry"
] | 49 | [
"Organic compounds",
"Organic minerals"
] |
71,398,694 | https://en.wikipedia.org/wiki/Cosmos%20%282019%20film%29 | Cosmos is a 2019 science fiction film written, directed and produced by Elliot and Zander Weaver in their feature film debut. The film stars Tom England, Joshua Ford, Arjun Singh Panam and Ben Vardy. It was released in late 2019 in the United States.
Plot
Three young astronomers are baffled once the newest team member discovers radio signals of a seemingly impossible origin on 1420.163, in the water hole. After an unexplained power surge deletes crucial recordings, the team members unite and discover that the radio signals resolve to a response to the Arecibo message, a message beamed into space via radio waves in 1974, broadcast by a spacecraft in low Earth orbit using a cloaking system that renders the craft invisible on the visual spectrum but visible in infrared. After the team race to a local radio telescope array to get a new battery when a low battery threatens to halt their investigation, it turns out that the team were the first to receive and identify the message. At the finale, SETI coordinates a global message to be beamed to the craft: "Welcome to Earth", at which point the craft decloaks.
Cast
Tom England
Joshua Ford
Arjun Singh Panam
Ben Vardy
Production
The film was made in Birmingham, England. Pre-production started in 2013 followed by principal photography in 2015. The film took five years to make and was shot on the Blackmagic Pocket Cinema Camera 1080p. Other than the soundtrack, the Weavers handled the majority of post-production duties themselves. It is their feature film debut.
Release
A trailer was released on 12 November 2018. The film had a theatrical and on demand release on 8 November 2019. It was distributed by Gravitas Ventures.
The film has only been released as region 1 on DVD and Blu-Ray due to Gravitas Ventures not owning the world rights for the film.
Reception
A review at HorrorBuzz compared the film to Close Encounters of the Third Kind and Arrival, calling it a "must see." Philip Henry at Movie Burner Entertainment claimed the script had imperfections but that they did not deter from it being compelling. Pedram Türkoğlu compared it to Contact, dealing with radio wave detection. Skyline Indie Film Festival recommended the film.
See also
Wow! signal – 1977 narrowband radio signal from SETI
References
External links
2010s science fiction adventure films
British science fiction adventure films
Films about astronomy
2010s English-language films
Films shot in England
Films set in the United Kingdom
2019 science fiction films
2010s British films
Films about radio
2019 directorial debut films
English-language science fiction adventure films | Cosmos (2019 film) | [
"Astronomy"
] | 521 | [
"Films about astronomy",
"Works about astronomy"
] |
71,399,618 | https://en.wikipedia.org/wiki/May%20Contain%20Hackers | May Contain Hackers, abbreviated MCH2022, was a nonprofit outdoor hacker conference and festival in The Netherlands.
It is part of the quadrennial hacker camps that started in 1989 with the Galactic Hacker Party in Amsterdam. This conference was part of a sequence that began with the Galactic Hacker Party in 1989, followed by Hacking at the End of the Universe in 1993, Hacking In Progress in 1997, Hackers At Large in 2001, What the Hack in 2005, Hacking at Random in 2009, Observe. Hack. Make. in 2013, and Still Hacking Anyway in 2017.
The camp took place from 22 to 26 July on a scouts terrain in Zeewolde. At least 3219 hackers and technology minded people from 50 countries participated in workshops and discussions. During the camp, lectures and workshops were held in conference tents, with notable speakers being Mikko Hyppönen and the Dutch Government's Ministry of Health, Welfare and Sport.
Activities
The conference had 233 sessions from 179 speakers, 144 talks, 61 workshops, 27 music performances, and movie watching sessions. All scheduled talks were live-streamed and recorded, and published online at the streaming Portal of the Chaos Computer Club, at media.ccc.de/c/MCH2022.
Infrastructure
Participants had Gigabit Ethernet through Datenklos (repurposed new chemical toilets with Ethernet switches). A network of 130 Wireless access points provided high-speed network covering the entire camp, with both Public, Encrypted, Spacenet and Eduroam service. The camp also featured a local DECT phone network, with optional SIP service SIP for app-based calling from modern devices like Android, iPhone, and laptops. Also found on all fields of the camp are the field phones that could be used by those without a DECT or smartphone.
Volunteering
The camp operated an extensive network of volunteering by participants (also called "Angels", using the shift-planning system "Engelsystem", developed by the German computer club Chaos Computer Club. Volunteers were rewarded with free meals for every two hours worked, with 946 volunteers spending a total of 6921 hours (or 41.2 weeks) in the span of 5 days. Besides all the registered angel hours, many additional volunteers helped with buildup and tear-down.
References
External links
Official website
Hacker conventions
Hacker_camps | May Contain Hackers | [
"Technology"
] | 479 | [
"Computing stubs",
"Computer conference stubs"
] |
71,399,656 | https://en.wikipedia.org/wiki/Launch%20and%20commissioning%20of%20the%20James%20Webb%20Space%20Telescope | The James Webb Space Telescope (JWST) is a space telescope designed primarily to conduct infrared astronomy. Its complex launch and commissioning process lasted from late 2021 until mid-2022.
The U.S. National Aeronautics and Space Administration (NASA) led JWST's development in collaboration with the European Space Agency (ESA) and the Canadian Space Agency (CSA), beginning in the late 1990s. The NASA Goddard Space Flight Center (GSFC) in Maryland managed telescope development, the Space Telescope Science Institute in Baltimore on the Homewood Campus of Johns Hopkins University operates JWST, and the prime contractor was Northrop Grumman. The telescope is named after James E. Webb, who was the administrator of NASA from 1961 to 1968 during the Mercury, Gemini, and Apollo programs.
The launch (designated Ariane flight VA256) took place as scheduled at 12:20 UTC on 25 December 2021 on an Ariane 5 rocket that lifted off from the Guiana Space Centre in French Guiana. Upon successful launch, NASA administrator Bill Nelson called it "a great day for planet Earth". The telescope was confirmed to be receiving power, starting a two-week deployment phase of its parts and traveling to its target destination. A six-month commissioning phase followed of testing and calibrating scientific instruments, culminating in the first scientific results being publicly shared in July 2022. The telescope's nominal mission time is five years, with a goal of ten years. An orbit is unstable, so JWST needs to use propellant to maintain its halo orbit around (known as station-keeping) to prevent the telescope from drifting away from its orbital position. It was designed to carry enough propellant for 10 years, but the precision of the Ariane 5 launch and the first midcourse correction were credited with saving enough onboard fuel that JWST may be able to maintain its orbit for around 20 years instead. Space.com called the launch "flawless".
Launch
Rocket preparation
Ariane 5 is a heavy lift two-stage rocket with two solid fuel boosters. It was used in its ECA variant, which offers the highest payload mass capacity. The total launch mass of the vehicle is of the order of . Spacecraft fuelling operations began on 25 November 2021, the fuelling system was disconnected on 3 December 2021, and verifications were concluded on 5 December 2021. The telescope's fuel system was filled with approximately of hydrazine and of dinitrogen tetroxide, needed to reach and maintain its orbit after separation from the launch vehicle. Following the rocket, which had already arrived on 29 November 2021, the telescope was moved to the final assembly building ( or BAF) on 7 December 2021. The payload was encapsulated inside the fairing on top of the rocket on 21 December 2021.
Scientists and engineers who worked on the project described their feelings of anticipation and anxiety about the launch of the exhaustively tested nearly $10 billion instrument, commenting that it would be "an exciting moment" and they would feel "terrified the entire time".
Liftoff
The launch (designated Ariane flight VA256) took place as scheduled at 12:20 UTC on 25 December 2021 on an Ariane 5 rocket that lifted off from the Guiana Space Centre in French Guiana. Upon successful launch, NASA administrator Bill Nelson called it "a great day for planet Earth". The telescope was confirmed to be receiving power, starting a two-week deployment phase of its parts and traveling to its target destination. The observatory was attached to the Ariane 5 via a launch vehicle adapter ring which could be used by a future spacecraft to grapple the observatory to attempt to fix gross deployment problems. However, the telescope itself is not serviceable, and astronauts would not be able to perform tasks such as swapping instruments, as with the Hubble Telescope. The telescope was released from the upper stage 27 minutes 7 seconds after launch, beginning a 30-day adjustment to place the telescope in a Lissajous orbit around the Lagrange point.
The telescope was launched with slightly less speed than needed to reach its final orbit, and slowed down as it travelled away from Earth, in order to reach L2 with only the velocity needed to enter its orbit there. The telescope reached L2 on 24 January 2022. The flight included three planned course corrections to adjust its speed and direction. This is because the observatory could recover from underthrust (going too slowly), but could not recover from overthrust (going too fast) – to protect highly temperature-sensitive instruments, the sunshield must remain between telescope and Sun, so the spacecraft could not turn around or use its thrusters to slow down.
Transit and structural deployment
The James Webb Space Telescope was released from the rocket upper stage 27 minutes after a flawless launch. Starting 31 minutes after launch, and continuing for about 13 days, JWST began the process of deploying its solar array, antenna, sunshield, and mirrors. Nearly all deployment actions are commanded by the Space Telescope Science Institute in Baltimore, except for two early automatic steps, solar panel unfolding and communication antenna deployment. The mission was designed to give ground controllers flexibility to change or modify the deployment sequence in case of problems.
The electricity-generating solar panel deployed on the day of launch, one and a half minutes after the telescope separated from the Ariane rocket second stage; this took place slightly sooner than expected because launch rotation was much closer to ideal than deployment plans had envisaged. The separation and solar panel extension were both visible in a live feed from a camera on the rocket.
After deployment of the solar arrays, power output was reduced due to a factory pre-set duty cycle in the array regulator module which was set prior to launch. Power usage was greater than that supplied by the solar arrays and this resulted in increased drawdown of the telescope's batteries and higher than expected voltage. To ensure power delivery would be sufficient for spacecraft and science operations, the solar panels were reset and duty cycles were optimized to account for the real world conditions observed including array temperatures. Higher than desired temperatures were observed in some of the shade deployment motors. While the motors remained well within their operational tolerances, to ensure greater margins the spacecraft's attitude was adjusted to aid the motors in reaching their desired temperatures and the motors were rebalanced. This was done based on results from simulator testing. The majority of forecast models of vehicle behavior and conditions matched the operational evolution in space.
At 7:50p.m. EST on 25 December 2021, about 12 hours after launch, the telescope's pair of primary rockets began firing for 65 minutes to make the first of three planned mid-course corrections. On day two, the high gain communication antenna deployed automatically.
On 27 December 2021, at 60 hours after launch, Webb's rockets fired for nine minutes and 27 seconds to make the second of three mid-course corrections for the telescope to arrive at its L2 destination. On 28 December 2021, three days after launch, mission controllers began the multi-day deployment of Webb's all-important sunshield. Controllers sent commands that successfully lowered the forward and aft pallet structures, which contain the sunshield. This deployment precedes the actual unfolding and extension of the delicate shield membranes, which are pulled out of the pallets by telescoping beams in a subsequent step.
On 29 December 2021, controllers successfully extended the Deployable Tower Assembly, a pipe-like column, which moved apart the two main segments of the observatory, the telescope with its mirrors and scientific instruments, and the "bus" holding electronics and propulsion. The assembly lengthened in a process that lasted six and a half hours, including many preparatory commands. Deployment created the needed distance between the JWST segments to allow extreme cooling of the telescope and room for the sunshield to unfold. On 30 December 2021, controllers successfully completed two more steps in unpacking the observatory. First, commands deployed the aft "momentum flap", a device that provides balance against solar pressure on the sunshield, saving fuel by reducing the need for thruster firing to maintain Webb's orientation. Next, mission control released and rolled up covers that protect the sunshield, exposing it to space for the first time.
On 31 December 2021, the ground team extended the two telescoping "mid booms" from the left and right sides of the observatory, pulling the five sunshield membranes out of their folded stowage in the fore and aft pallets, which were lowered three days earlier. Deployment of the left side boom (in relation to pointing direction of the main mirror) was delayed when mission control did not initially receive confirmation that the sunshield cover had fully rolled up. After looking at extra data for confirmation, the team proceeded to extend the booms. The left side deployed in 3 hours and 19 minutes; the right side took 3 hours and 42 minutes. With that step, Webb's sunshield resembled its complete, kite-shaped form and extended to its full width. Commands to separate and tension the membranes were to follow and were expected to take several days.
After resting on New Year's Day, the ground team delayed sunshield tensioning one day to allow time to optimize the observatory's array of solar panels and to adjust the orientation of the observatory slightly to cool the slightly hotter-than-expected sunshield deployment motors. Tensioning of layer one, closest to the Sun and largest of the five in the sunshield, began on 3 January 2022, and was completed at 3:48p.m. EST. Tensioning of the second and third layers began at 4:09p.m. EST and took two hours and 25 minutes. On 4 January, controllers successfully tensioned the last two layers, four and five, completing the task at 11:59a.m. EST.
On 5 January 2022, mission control successfully deployed the telescope's secondary mirror, which locked itself into place to a tolerance of about one and a half millimeters.
The last step of structural deployment was to unfold the wings of the primary mirror. Each panel consists of three primary mirror segments and had to be folded to allow the space telescope to be installed in the fairing of the Ariane rocket for the launch of the telescope. On 7 January 2022, NASA deployed and locked in place the port-side wing, and on 8 January, the starboard-side mirror wing. This successfully completed the structural deployment of the observatory.
On 24 January 2022, at 2:00p.m. EST, nearly a month after launch, a third and final course correction took place, inserting JWST into its planned halo orbit around the Sun–Earth L2 point.
Commissioning and testing
On 12 January 2022, while still in transit, mirror alignment began. The primary mirror segments and secondary mirror were moved away from their protective launch positions. This took about 10 days, because the 132 actuator motors are designed to fine-tune the mirror positions at microscopic accuracy (10 nanometer increments) and must each move over 1.2 million increments (12.5 mm) during initial alignment. Additionally, to reduce risk and complexity, and to minimize heat production near the cooling mirrors, only one actuator was moved at a time and the actuators only operated for short periods at a time, limiting total speed to about 1 mm per day. The 18 radius of curvature (ROC) actuators, which adjust curvature of the primary mirror segments, were also moved from launch position at the same time.
After being freed from launch protection, the 18 mirror segments are being fine tuned and aligned to work as a single mirror, a process expected to take around three of the five months allowed for commissioning and testing. Commissioning is complicated by the fact that the telescope's performance and precise shapes of some components will also change microscopically as it continues to cool. Heaters used to protect against water and ice condensation will no longer be needed and will gradually be switched off.
Mirror alignment requires each of the 18 mirror segments, and the secondary mirror, to be positioned to within 50 nanometers. NASA compares the required accuracy by analogy: "If the Webb primary mirror were the size of the United States, each [mirror] segment would be the size of Texas, and the team would need to line the height of those Texas-sized segments up with each other to an accuracy of about 1.5 inches".
Mirror alignment is a complex operation split into seven phases, that has been repeatedly rehearsed using a 1:6 scale model of the telescope. Once the mirrors reach , NIRCam targets a bright star, the 6th magnitude star HD 84406 in Ursa Major. (HD 84406 is bright and easily identified, will stay in view for the entire 3 months of commissioning, and is in part of the sky with fewer other stars.) To do this, NIRCam takes 1560 images of the sky (156 images with each of its 10 sensors) and uses these wide-ranging images to determine where in the sky each segment of the main mirror is initially pointing. Initially, the individual primary mirror segments will be greatly misaligned, so the image will contain 18 separate, blurry, images of the star field, each containing an image of the target star. The 18 images of HD 84406 are matched to their respective mirror segments, and the 18 segments are brought into approximate alignment centered on the star ("Segment Image Identification"). Each segment is then individually corrected of its major focusing errors, using a technique called phase retrieval, resulting in 18 separate, but individually good quality, images from the 18 mirror segments ("Segment Alignment"). The 18 images from each segment, are then moved so they precisely overlap to create a single image ("Image Stacking").
With the mirrors now positioned for almost correct images, they must be fine tuned to their operational accuracy of 50 nanometers, less than one wavelength of the light that will be detected. A technique called dispersed fringe sensing compares images from 20 pairings of mirrors, allowing most of the errors to be corrected ("Coarse Phasing"), and then the same technique is used with special optical elements to introduce ±4 and ±8 waves of defocus to each segment's image, allowing detection and correction of almost all remaining errors ("Fine Phasing"). These two processes are repeated three times, and Fine Phasing will be routinely checked throughout the telescope's operation.
After three rounds of Coarse and Fine Phasing, the telescope will be well aligned at one place in the NIRCam field of view. Measurements will be made at various points in the captured image, across all instruments, and corrections calculated from the detected variations in intensity, giving a well-aligned outcome across all instruments ("Telescope Alignment Over Instrument Fields of View").
Finally, a last round of Fine Phasing and checks of image quality on all instruments is performed, to ensure that any small residual errors remaining from the previous steps, are corrected ("Iterate Alignment for Final Correction"). The telescope's mirror segments are then aligned and able to capture precise focused images. If needed, the process allows for earlier steps to be retested again, to ensure accuracy.
In preparation for alignment, NASA announced at 19:28 UTC on 3 February 2022, that NIRCam had detected the telescope's first photons (although not yet complete images). On 11 February 2022, NASA announced the telescope had almost completed phase 1 of alignment, with every segment of its primary mirror having located and imaged the target star HD 84406, and all segments brought into approximate alignment. Phase 1 alignment was completed on 18 February 2022, and a week later, phases 2 and 3 were also completed on 25 February 2022. This means the 18 segments are working in unison, however until all 7 phases are complete, the segments still act as 18 smaller telescopes rather than one larger one. At the same time as the primary mirror is being commissioned, hundreds of other instrument commissioning and calibration tasks are also ongoing.
Gallery of calibration and test images
See also
Timeline of the James Webb Space Telescope
Notes
References
James Webb Space Telescope
2021 in science
Goddard Space Flight Center
NASA programs
Space program of Canada
2021 in French Guiana
Articles containing video clips | Launch and commissioning of the James Webb Space Telescope | [
"Astronomy"
] | 3,351 | [
"Space telescopes",
"James Webb Space Telescope"
] |
71,402,067 | https://en.wikipedia.org/wiki/Kamikatsu%20Zero-waste%20Center | Kamikatsu Zero-waste Center (also known as "WHY") is a waste management and materials recovery facility that recycles over 80 percent of the waste produced in Kamikatsu, which is much higher than the 20 percent average in the rest of Japan. It is at the center of what The Washington Post describes as an "ambitious path toward a zero-waste life".
History
May 20, 2020 – Opening.
April 16, 2021 – Received the Architectural Institute of Japan Award for Best Work.
January 24, 2021 – Received Grand Prize for the Ministry of Internal Affairs and Communications's Furusato Zukuri Awards.
Facilities
Made predominantly using waste materials such as used windows, the facilities are in the shape of a question mark.
Waste separation station, stock yard.
Kuru Kuru Shop, a reuse shop.
Learning center.
Laundromat and restrooms.
Collaborative laboratory.
Hotel WHY, where guests experience the town's recycling system.
Zero-waste policy in Kamikatsu
Kamikatsu is a "zero waste" town, all household waste is separated into 45 different categories and sent to be recycled. In 2008, a poll showed that 40 percent of residents were still unhappy about the aspect of the policy that required items to be washed. But the town continues the policy as it is cheaper and more environmentally friendly than purchasing an incinerator. The town recycles about 80 percent of its waste, compared to 20 percent in the rest of Japan, which is still relatively high compared to the USA at 9 percent and the Philippines at less than 5 percent, according to a Rappler article. The town has set a goal to become fully zero waste by 2020.
Architectural awards
2021 – Architectural Institute of Japan Award for Best Work
2021 – Japan Institute of Architects Environmental Architecture Award
2021 – Dezeen Awards, sustainable building of the year
References
External links
Kamikatsu Zero Waster Center
KAMIKATSU ZERO WASTE CENTER – Hiroshi Nakamura & NAP
Waste management
Recycling in Japan
Waste treatment technology
2020 establishments in Japan
Kamikatsu, Tokushima | Kamikatsu Zero-waste Center | [
"Chemistry",
"Engineering"
] | 416 | [
"Water treatment",
"Waste treatment technology",
"Environmental engineering"
] |
71,402,863 | https://en.wikipedia.org/wiki/Equisingularity | In algebraic geometry, an equisingularity is, roughly, a family of singularities that are not non-equivalent and is an important notion in singularity theory. There is no universal definition of equisingularity but Zariki's equisingularity is the most famous one. Zariski's equisingualrity, introduced in 1971 under the name " algebro-geometric equisingularity", gives a stratification that is different from the usual Whitney stratification on a real or complex algebraic variety.
See also
stratified space
References
Further reading
https://mathoverflow.net/questions/299314/a-general-definition-of-an-equisingular-family-of-singular-varieties
algebraic geometry | Equisingularity | [
"Mathematics"
] | 167 | [
"Fields of abstract algebra",
"Algebraic geometry"
] |
71,402,929 | https://en.wikipedia.org/wiki/Tame%20topology | In mathematics, a tame topology is a hypothetical topology proposed by Alexander Grothendieck in his research program Esquisse d’un programme under the French name topologie modérée (moderate topology). It is a topology in which the theory of dévissage can be applied to stratified structures such as semialgebraic or semianalytic sets, and which excludes some pathological spaces that do not correspond to intuitive notions of spaces.
Some authors consider an o-minimal structure to be a candidate for realizing tame topology in the real case. There are also some other suggestions.
See also
Thom's first isotopy lemma
References
External links
https://ncatlab.org/nlab/show/tame+topology
Algebraic analysis
Geometry education
Stratifications
Topology | Tame topology | [
"Physics",
"Mathematics"
] | 165 | [
"Stratifications",
"Topology stubs",
"Topology",
"Space",
"Geometry",
"Spacetime"
] |
71,403,171 | https://en.wikipedia.org/wiki/Leucocoprinus%20submontagnei | Leucocoprinus submontagnei is a species of mushroom producing fungus in the family Agaricaceae.
Taxonomy
It was first described in 1936 by the Belgian mycologist Maurice Beeli who classified the species as Lepiota Montagnei var. congolensis, a variant of Károly Kalchbrenner's earlier classification of Lepiota montagnei.
In 1977 it was reclassified as Leucocoprinus submontagnei by the Belgian mycologist Paul Heinemann.
Description
Leucocoprinus submontagnei is a small dapperling mushroom with white flesh.
Cap: 1–3 cm wide, campanulate or convex and expanding with age. The surface is white with a very dark brown or purplish-brown woolly (tomentose) centre disc or umbo. The scales are densely concentrated in the centre and sparsely scattered towards the cap edges, where striations extend about halfway up the cap. Gills: Free, crowded and white. Stem: Around 6 cm long and 2-3mm thick with a slightly thicker base. The surface is smooth and white whilst the interior is hollow. The membranous stem ring is white and described as narrow and funnel shaped. Spores: Ellipsoid or amygdaliform with a pore. 6.5-8.1 x 4.2-5.1 μm. The mushroom drys ochre-brown.
Habitat and distribution
L. submontagnei is scarcely recorded and little known. The specimen originally examined by Beeli was collected by M. Goossens-Fontana in 1923 in the Eala region of Zaire, Central Africa (now the Democratic Republic of the Congo) where they were found growing on the soil.
GBIF contains only one other recorded observation of this species. The second was recorded in Brazil in 1985 by Rolf Singer where they were found growing on dead Dicotyledon leaves in a flood plain.
A 2006 study documented this species from Kerala state, India.
Etymology
The specific epithet montagnei as used in the earlier classification was likely named to honour the French bryologist and mycologist Jean Pierre François Camille Montagne. There are also various species of moss, lichen and succulents named for him.
Similar species
The illustrations provided along with Beeli's study and the description from Heinemann are describing a mushroom which is very similar looking to Leucocoprinus heinemannii.
References
Leucocoprinus
Fungi described in 1936
Fungi of Africa
Taxa named by Paul Heinemann
Fungus species | Leucocoprinus submontagnei | [
"Biology"
] | 531 | [
"Fungi",
"Fungus species"
] |
71,403,660 | https://en.wikipedia.org/wiki/Leucocoprinus%20tropicus | Leucocoprinus tropicus is a species of mushroom producing fungus in the family Agaricaceae.
Taxonomy
It was first described in 1982 by the Indian mycologists K.V. Natarajan and B. Manjula who classified it as Leucocoprinus tropicus.
Description
Leucocoprinus tropicus is a dapperling mushroom with thin whitish-yellow flesh.
Cap: 6.5-7cm wide, flattened convex and depressing with maturity. The surface is white with a brownish umbo and loose brown scales scattered across the surface which may disappear with age. There are striations at the cap edges. Gills: Free, crowded and white. Stem: 9-10 cm tall and 5-8mm thick without a noticeably thicker base or any tapering. The surface is white and the interior hollow and white mycelium may be present at the base. The persistent, membranous stem ring is white and located towards the top of the stem (superior). Spore print: White. Spores: Ellipsoid with a germ pore. 8.8-13.2 x 5.5-7.7 μm.
Habitat and distribution
L. tropicus is scarcely recorded and little known. The specimens studied by Natarajan and Manjula were found growing on soil at Raj Bhavan in Tamil Nadu, India in November 1978.
Etymology
The specific epithet tropicus derives from the Greek tropikós meaning tropical.
References
Leucocoprinus
Fungi described in 1982
Fungi of India
Fungus species | Leucocoprinus tropicus | [
"Biology"
] | 326 | [
"Fungi",
"Fungus species"
] |
71,403,855 | https://en.wikipedia.org/wiki/1%2C4-Diisocyanobutane | 1,4-Diisocyanobutane is an organic compound. Its structural formula is CN(CH2)4NC, which similar to adiponitrile but with carbon and nitrogen of cyanide groups switching places. It has been used as a ligand in the formation of organometallic complexes, such as with rhodium - [Rh2(CNC8H14NC)4]2+.
References
Isocyanides | 1,4-Diisocyanobutane | [
"Chemistry"
] | 97 | [
"Functional groups",
"Organic compounds",
"Isocyanides",
"Organic compound stubs",
"Organic chemistry stubs"
] |
71,403,990 | https://en.wikipedia.org/wiki/Rhizorhabdus | Rhizorhabdus is a genus of bacteria. Its name is derived from the latin rhiza, meaning root, and rhabdos, meaning rod. Members of this genus, including Rhizorhabdus wittichii and five other species with sequenced genomes, are associated with soil or plant roots.
References
Bacteria genera
Sphingomonadales
Taxa described in 2014 | Rhizorhabdus | [
"Biology"
] | 82 | [
"Bacteria stubs",
"Bacteria"
] |
71,405,379 | https://en.wikipedia.org/wiki/Butamifos | Butamifos is an herbicide that is used to control weeds.
Production
The production of butamifos is based on N-[chloro(ethoxy)phosphinothioyl]butan-2-amine and 5-methyl-2-nitrophenol and is described in the following reaction sequence:
Properties
Butamifos is a chiral molecule. The technical product uses a mixture of the (R)- and (S)-isomers.
In a study, the level of pesticide contamination in soil and water of an agriculturally intensive area in Nepal was investigated. Endosulfan, Iprobefos, monocrotophos, mevinphos, and butamifos were detected in water samples, while cypermethrin, dichlorvos, and cyfluthrin were detected in soil samples. The increased concentration of butamifos in water may be due to higher water solubility and lower affinity for adsorption in soil.
Use
Application and mode of action
Butamifos is used on beans, turf and various vegetables. The active ingredient is a non-systemic, selective herbicide. Its effect is based on inhibition of microtubule formation. It also acts as an acetylcholinesterase inhibitor, making it moderately toxic to mammals.
Trade name
A crop protection product containing the active ingredient butamifos is marketed under the trade name Cremart.
Registration
No plant protection products containing butamifos are registered in the European Union or Switzerland.
References
Herbicides
Nitrotoluene derivatives
Ethyl esters
Toluenes | Butamifos | [
"Biology"
] | 340 | [
"Herbicides",
"Biocides"
] |
71,406,200 | https://en.wikipedia.org/wiki/HD%2010800 | HD 10800, also known as HR 512 or Gliese 67.1, is a triple star located in the southern circumpolar constellation Octans. It has a combined apparent magnitude of 5.87, allowing it to be faintly seen with the naked eye. The system is relatively close at a distance of 88.1 light years but is drifting closer with a heliocentric radial velocity .
The system has a blended spectral classification of G1 V, indicating an ordinary G-type main-sequence star. The primary is a spectroscopic binary consisting of a G-type and K-type star circling around each other in 19 days. HD 10800B has a class of G2 V, the same spectral class as our own Sun. The AB pair take 1.7 years to orbit each other.
HD 10800A
The primary (Aa) has 109% the mass of the Sun and a radius 1.1 times that of the Sun. It radiates at 1.82 times the luminosity of the Sun from its photosphere at an effective temperature of , giving a yellow hue. HD 10800A has a metallicity 81% that of the Sun, making it slightly metal deficient. At an age of 5 billion years, it spins with a projected rotational velocity of . The close companion (Ab) has a mass 69% that of the Sun.
HD 10800B
HD 10800B, the slightly distant companion, has the same mass of the Sun but is slightly cooler (37 K difference) and dimmer, with a luminosity 98% that of the Sun. The object is only marginally older than the Sun at an age of 4.8 billion years.
References
G-type main-sequence stars
K-type stars
Spectroscopic binaries
Octans
Octantis, 3
0067.1
PD-83 0027
10800
0512
007601
Triple star systems | HD 10800 | [
"Astronomy"
] | 394 | [
"Octans",
"Constellations"
] |
71,406,489 | https://en.wikipedia.org/wiki/Solid%20State%20Logic%20SL%204000 | The Solid State Logic SL 4000 is a series of large-format analogue mixing consoles designed and manufactured by Solid State Logic (SSL) from 1976 to 2002. 4000 Series consoles were widely adopted by major commercial recording studios in the 1980s. In 2004, the SL 4000 was inducted into the TECnology Hall of Fame, an honor given to "products and innovations that have had an enduring impact on the development of audio technology."
History
Origin of the SSL console
SSL founder Colin Sanders owned and operated Acorn Studios, a recording studio in Stonesfield, Oxfordshire. When he sought a recording console with routing flexibility and settings recall unavailable on recording consoles at that time, Sanders applied his experience to design and build a mixing console himself, resulting in the SL 4000 A Series large-format analogue mixing console, which featured one-button switching between recording, tracking and mixdown modes. A total of two SL 4000 A Series consoles were built, the beginning of a series of products that would define and establish SSL as a company over the next two decades.
B Series
The SL 4000 B Series, introduced in 1976, revolutionized the recording industry by combining the in-line mixing console with a computer which provided fader automation and programmable tape transport auto-location functionality., The B Series was in production for four years, during which a total of six B Series consoles were built and sold, the first B Series console purchased by Abbey Road Studios in London, England. The second B Series console was purchased by Le Studio in Morin-Heights, Canada, where it was used in the recording of such notable albums as Moving Pictures and several subsequent Rush albums, as well as Bryan Adams Cuts Like a Knife. Kendun Recorders in Burbank, California also purchased an SL 4000 B.
Another early SL 4000 B was purchased by Virgin Records' Townhouse Studios in London, and it was with that console that engineer Hugh Padgham accidentally discovered gated reverb while recording Phil Collins' drum parts for Peter Gabriel's 1980 song "Intruder". The console featured a "Listen Mic", or reverse talkback function intended to allow a musician in the studio to communicate with control room personnel via an overhead microphone. To compensate for sound level differences of musicians that may or may not be near the microphone, SSL's "Listen Mic" circuit employed gating and extreme compression, so when Padgham activated the "Listen Mic" while Collins was talking and playing, it resulted in the gated reverb drum sound. Padgham and producer Steve Lilywhite liked the sound so much that they had the console modified overnight to enable recording of the console's talkback circuit. Collins, Lilywhite, and Padgham again used the effect on Collins' signature 1981 single "In the Air Tonight", and the gated reverb drum sound technique became widely used and imitated throughout the 1980s, with SSL revising the design of future consoles so that the "Listen Mic" could be recorded without any modification. Other notable albums recorded by Lillywhite on Townhouse's SL 4000 B included XTC's Drums and Wires and Simple Minds' Once Upon a Time.
E and G Series
The SL 4000 E Series, introduced in 1979, combined the functionality of a mixing console with centralized signal processing control, machine control, fader automation, and Total Recall, which enabled the user to save the settings of all of the mixers' rotary controls on a 5¼ inch floppy disk, then reset them to those previous settings using a color-coded display. The E Series offered sonic improvements, increased routing flexibility, a new 4-band EQ section developed in collaboration with George Martin (now commonly referred to as the "Black Knob" EQ), and was the first console to offer a compressor/gate on every channel as well as a master bus compressor.
The combination of the ability to save and recall mixer settings, a dedicated dynamics section, and a dedicated compressor/gate/expander and parametric EQ on every channel, and SSL's flexible routing drove widespread adoption of the SL 4000 E Series consoles and its successors and variants in professional recording studios, and in 1996 Billboard's Studio Action Chart reported that 83% of number one singles that year had been produced using an SSL board. The company claims that more platinum albums have been recorded on SSL mixing consoles than any other company's equipment combined.
The first two 4000 E consoles were purchased by Battery Studios and RG Jones Recording Studios, closely followed by Eden Studios and Sarm Studios. Hansa Tonstudio purchased three custom SL 4000 E consoles in "Hansa blue"; two of these consoles are still in use.
SSL introduced the SL 4000 G Series at the AES New York Convention in 1987, which again offered a redesigned EQ, among other improvements.
The SL 4000 E Series and G Series consoles were later also made available in 5000 Series, 6000 Series, and 8000 Series formats, which offered various routing and bussing configurations to address the needs of sound for the recording, film, video, and broadcast markets.
Notable users
Notable mixing engineers using SL 4000 Series consoles include Bob Clearmountain, Steve Lillywhite, Chris Lord-Alge, Tom Lord-Alge, Andy Wallace, Mark "Spike" Stent, Will Schillinge, Alan Moulder, and Trevor Horn.
Second-hand market
Even though Solid State Logic ceased manufacturing SL 4000 Series consoles in 2002, there is still demand for these large-format analog recording consoles which supports a large second-hand market and a number of third-party companies offering spare parts.
The SL 4000 B serial number 11, originally purchased by Le Studio in Montreal where it was used from 1980-1985, recording such albums as Rush's Moving Pictures, is now in use at Tree Sound Studios in Atlanta.
The SL 4000 E serial number #001 is currently in service at Sonic Ranch Recording Studios in Tornillo, Texas. The SL 4000 E (with upgraded G+ computer) from Genesis' The Farm Studio now in use at Essex Recording Studios. The SL 4000 E originally built in 1984 for Battery Studios in London was purchased and refurbished in 2018 for use at 2noisy studio in Azpetia, Spain.
The SL 4000 G+ Special Edition console previously used at Roundhouse Recording Studios in London was purchased by Massive Attack in 2005 for use in their new studio facility. The SL 4000 G+ from Eden Studios is now in use at Blue Bell Hill in Kent, England. SL 4000 G+ previously used at Real World Studios and at AIR Studios is now in use at Abbey Recording Company.
Recreations and software emulations
The signature sounds of the SSL 4000 E Series EQ, as well as the G Series EQ and Bus Compressor are still in demand, and as such they have been re-created by SSL and included as a feature marketed in new SSL products.
Additionally, SSL and Universal Audio have developed and introduced SSL-branded software plug-in recreations of those E Series and G Series console features.
References
Sound recording technology
Mixing consoles | Solid State Logic SL 4000 | [
"Technology"
] | 1,452 | [
"Recording devices",
"Sound recording technology"
] |
71,407,586 | https://en.wikipedia.org/wiki/Phaffomycetaceae | The Phaffomycetaceae are a family of yeasts in the order Saccharomycetales that reproduce by budding. Species in the family have a widespread distribution.
The family are named after Phaffomyces but it was placed in the Pichiaceae fungi family.
It is found to be linked to Equine grass sickness (EGS) via pasture mycotoxicosis, which comprises a very large and diverse population of fungi. It is found in silage, including lactic acid bacteria, yeasts and molds.
It is found in fermented Ethiopian honey wine, Tej''', and can affect bagasse (the waste product) of sugarcane, with other yeast fungi.
Genera
According to GBIF;
Figures in brackets are approx. how many species per genus.
Genus Wickerhamomyces'' used to be placed within Phaffomycetaceae, until 2008 when it was separated and placed within its own order Wickerhamomycetaceae.
References
Other sources
Kurtzman, C. P., C. J. Robnett, and E. Basehoar-Powers. 2008. Phylogenetic relationships among species of Pichia, Issatchenkia and Williopsis determined from multigene sequence analysis, and the proposal of Barnettozyma gen. nov., Lindnera gen. nov. and Wickerhamomyces gen. nov. FEMS Yeast Res 8:939-54.
Yeasts
Saccharomycetes
Ascomycota families | Phaffomycetaceae | [
"Biology"
] | 317 | [
"Yeasts",
"Fungi"
] |
71,407,626 | https://en.wikipedia.org/wiki/HD%20194612 | HD 194612 (HR 7812) is a solitary orange hued star located in the southern circumpolar constellation Octans. It has an apparent magnitude of 5.9, making it visible to the naked eye under ideal conditions. Parallax measurements place it at a distance of 760 light years and it has a low heliocentric radial velocity of .
This is a red giant with a stellar classification of K5 III, and Gaia DR3 stellar evolution models place it on the red giant branch. It has double the mass of the Sun and an enlarged radius of due to its evolved status. It shines with a luminosity of from its photosphere at an effective temperature of . Like many giants, HD 194612 has a comparatively modest projected rotational velocity, which is around .
References
K-type giants
Octans
194612
101843
7812
PD-81 00906
Octantis, 49 | HD 194612 | [
"Astronomy"
] | 188 | [
"Octans",
"Constellations"
] |
71,408,365 | https://en.wikipedia.org/wiki/Asus%20ZenFone%209 | The Asus ZenFone 9 is an Android smartphone designed, developed, and manufactured by Asus as part of its Asus ZenFone line of smartphones. It was announced on July 28, 2022.
References
Asus ZenFone
Mobile phones introduced in 2022
Mobile phones with 8K video recording
Mobile phones with multiple rear cameras
Flagship smartphones | Asus ZenFone 9 | [
"Technology"
] | 74 | [
"Mobile technology stubs",
"Discontinued flagship smartphones",
"Flagship smartphones",
"Mobile phone stubs"
] |
71,408,749 | https://en.wikipedia.org/wiki/Views%20on%20circumcision | Circumcision has played a significant cultural, social, and religious role in various global cultures over the course of world history. This has subsequently led to widely varying views related to the practice.
Abrahamic faiths
The rite plays a major role in the Abrahamic faiths. Mainstream forms of Judaism view the practice as an integral and central religious obligation that is one of the most important commandments for Jews, while differing schools of interpretation within Islam view it either as an obligation or recommended.
Circumcision has also played a major role in Christian history and theology. Covenant theology largely views the Christian sacrament of baptism as fulfilling the Israelite practice of circumcision, both being signs and seals of the covenant of grace. With the exception of the Coptics, Ethiopian Orthodox and Eritrean Orthodox where circumcision is an integral or established or requirement practice for members of these churches, the large majority of mainstream Christian denominations maintain a neutral position on it in with respect to medical or cultural reasons, although all of them honor the circumcision of Jesus and condemn the rite when it is viewed as a means or requirement towards an individual's justification. According to Scholar Heather L. Armstrong of University of Southampton, many Christians have been circumcised for reasons such as family preferences, depending on Biblical interpretation by individuals, medical or cultural reasons.
Samaritanism view the circumcision as an integral and central religious obligation that is one of the most important commandments for Samaritans. Circumcision is widely practiced by the Druze, the procedure is practiced as a cultural tradition, and has no religious significance in the Druze faith. Some Druses do not circumcise their male children, and refuse to observe what they see as a "common Muslim practice".
Indian faiths
Indian religions, such as Hinduism and Sikhism, strongly prohibit the practice of routine circumcision. Hinduism discourages non-medical circumcision, as according to them, the body is made by the almighty God, and nobody has right to alter it without the concern of the person who is going for it. Sikhism does not require the elective circumcision of its followers and strongly criticizes the practice, and Sikh infants are not circumcised. Buddhism appears to have a neutral view on circumcision.
African cultures
Circumcision in Africa, and the rites of initiation in Africa, as well as "the frequent resemblance between details of ceremonial procedure in areas thousands of kilometres apart, indicate that the circumcision ritual has an old tradition behind it and in its present form is the result of a long process of development." Circumcision is prevalent among 92% of men in North Africa and around 62% in Sub-Saharan Africa. In western and northern parts of Africa it is mainly performed for religious reasons, whereas in southern parts of Africa it rarely performed in neonates, instead being a rite of passage into manhood.
In some African and Eastern Christian denominations male circumcision is an integral or established practice, and require that their male members undergo circumcision. Circumcision is near-universal among Coptic Christians, Ethiopian Orthodox and Eritrean Orthodox, and they practice circumcision as a rite of passage.
Certain African cultural groups, such as the Yoruba and the Igbo of Nigeria, customarily circumcise their infant sons. The procedure is also practiced by some cultural groups or individual family lines in Sudan, Democratic Republic of the Congo, Uganda and in southern Africa. For some of these groups, circumcision appears to be purely cultural, done with no particular religious significance or intention to distinguish members of a group. For others, circumcision might be done for purification, or it may be interpreted as a mark of subjugation. Among these groups, even when circumcision is done for reasons of tradition, it is often done in hospitals.
Asian cultures
In the Philippines, where four-fifths of Filipinos profess Roman Catholicism, circumcision is known as "tuli" and is generally viewed as a rite of passage. An overwhelming majority of Filipino men are circumcised. According to the United Nations World Health Organisation:In the Philippines, where circumcision is almost universal and typically occurs at age 10–14 years, a survey of boys found strong evidence of social determinants, with two thirds of boys choosing to be circumcised simply "to avoid being uncircumcised", and 41% stating that it was "part of the tradition"The overall prevalence of circumcision in South Korea increased markedly in the second half of the 20th century, rising from near zero around 1950 to about 60% in 2000, with the most significant jumps in the last two decades of that time period. This is probably due to the influence of the United States, which established a trusteeship for the country following World War II.
Neither the Avesta nor the Zoroastrian Pahlavi texts mention circumcision, traditionally, Zoroastrians do not practice circumcision. Circumcision is not required in Yazidism, but is practised by some Yazidis due to regional customs. The ritual is usually performed soon after birth, it takes place on the knees of the kerîf (approximately "godfather"), with whom the child will have a life-long formal relationship.
Circumcision is forbidden in Mandaeism, and the sign of the Jews given to Abraham by God, circumcision, is considered abhorrent by the Mandaeans. According to the Mandaean doctrine a circumcised man cannot serve as a Mandaean priest.
Australian cultures
Circumcision is part of initiation rites in some Pacific Islander, and Australian aboriginal traditions in areas such as Arnhem Land, where the practice was introduced by Makassan traders from Sulawesi in the Indonesian Archipelago. Some Australian Aborigines use circumcision as a test of bravery and self-control as a part of a rite of passage into manhood, which results in full societal and ceremonial membership. Circumcision ceremonies among certain Australian aboriginal societies are noted for their painful nature, including subincision for some aboriginal peoples in the Western Desert.
In the Pacific, ritual circumcision is nearly universal in the Melanesian islands of Fiji and Vanuatu; Circumcision is also commonly practised in the Polynesian islands of Samoa, Tonga, Niue, and Tikopia. In Samoa, it is accompanied by a celebration.
See also
Tuli
References
Circumcision
Religious practices
Rites of passage
Sexuality and religion | Views on circumcision | [
"Biology"
] | 1,377 | [
"Behavior",
"Religious practices",
"Human behavior"
] |
71,409,538 | https://en.wikipedia.org/wiki/Necrobotics | Necrobotics is the practice of using biotic materials (or dead organisms) as robotic components. In July 2022, researchers in the Preston Innovation Lab at Rice University in Houston, Texas published a paper in Advanced Science introducing the concept and demonstrating its capability by repurposing dead spiders as robotic grippers and applying pressurized air to activate their gripping arms.
Necrobotics utilizes the spider's organic hydraulic system and their compact legs to create an efficient and simple gripper system. The necrobotic spider gripper is capable of lifting small and light objects, thereby serving as an alternative to complex and costly small mechanical grippers.
Background
The main appeal of the spider's body in necrobotics is its compact leg mechanism and use of hydraulic pressure. The spider's anatomy utilizes a simple hydraulic (fluid) pressure system. Spider legs have flexor muscles that naturally constrict their legs when relaxed. A force is required to straighten and extend their legs, which spiders accomplish by pumping hemolymph fluid (blood) through their joints as a means of hydraulic pressure. It takes no external power to curl their legs due to their flexor muscles' natural curled state.
In July 2022, researchers in the Preston Innovation Lab at Rice University published a paper detailing their experiments with the gripper. Although dead spiders no longer produce hemolymph, Te Faye Yap (lead author and mechanical engineering graduate) found that pumping air through a needle into the spider's cephalothorax accomplishes the same results as hemolymph. The original hydraulic (fluid) system is essentially converted into a pneumatic (air) system.
Fabrication
Obtain a spider (preferably a wolf spider)
Euthanize the spider using a cold temperature of around -4°C for 5-7 days
Insert a 25 gauge hypodermic needle into the spider's cephalothorax (main body)
Apply glue around the needle to form a seal and allow it to dry
Connect a syringe or pump to the needle
Extend the spider's legs by pumping air in
Testing and Data
Internal Force Versus Gripping Force
The typical pressure in a resting spider's legs ranges from 4 kPa to 6.1 kPa. Researchers extended the legs by increasing the spider's internal pressure to 5.5 kPa. Pumping air into the body increases the internal pressure, causing the legs to expand. Pumping air out of the body decreases internal pressure, causing the legs to contract due to their flexor leg muscles. When the internal pressure decreases to 0 kPa, the gripper would be fully closed, allowing for the gripper to grasp objects. This action demonstrates that as internal pressure decreases, the gripping force increases. Inversely, when internal pressure increases, the gripping force decreases. By gripping individual weighted acetate beads, it is found that the necrobotic gripper achieves a maximum gripping force of 0.35 milinewtons.
Spider Weight Versus Gripping Force
To estimate the gripping forces of smaller and larger spiders, researchers created a plot to predict the gripping force relative to the size of the spider. The wolf spider's body weight is relatively equal to the gripping force of its legs. The mass of the gripper is 33.5 mg and can lift 1.3 times its body weight (43.6 mg or 0.35 mN). However, with larger spiders, the gripping force relative to body weight decreases. For example, a 200-gram goliath birdeater is predicted to lift 10% of its weight (20 grams or 196 mN). Though there is an inverse relationship between spider mass and gripping force, larger spiders exert greater gripping forces than smaller spiders.
Gripper Lifespan
The necrobotic gripper's functionality is entirely reliant on the structural integrity of the spider. If the spider were to break down easily and frequently, the gripper would not be practical. Using cyclic testing, a series of repeated actions, it is found that the necrobotic gripper can actuate 700 to 1000 times. After 1000 cycles, cracks begin forming on the membrane of the leg joints due to dehydration. Weakened and decomposing joints lead to frequent breakage and replacement, thereby serving as an obstacle in applying necrobotics to real-world scenarios.
One theorized fix to this issue is applying beeswax or a lubricant to the joints. Researchers found that over 10 days, the mass of an uncoated spider decreased 17 times more than the mass of a spider coated with beeswax. Lubricating joints combats dehydration and slows the loss of organic material.
Applications
Necrobotics can serve as a fast and precise alternative to mechanical components that are difficult to manufacture. Due to small mechanical grippers being costly and complex, the necrobotic gripper can be used as a replacement. Fabricating these pneumatic spider grippers can be done in under 30 minutes and have a relatively long lifespan of 1000 cycles. The necrobotic gripper is ideal for processes requiring delicate handling of materials and maneuvering light objects into tight spaces. There may also be applications in microelectronics where necrobotic grippers can handle simple pickup and dropping actions.
Besides the necrobotic spider gripper, there are no other robotic concepts under the necrobotics subfield. Future necrobotic concepts can utilize soft robotics and electrical stimuli to repurpose biotic material into biohybrid systems. Another application of necrobotics is utilizing preexisting bone structures to house robotic components.
Constraints
With the usage of organic material, there is a higher chance of the component decomposing and breaking down as opposed to traditional mechanical systems. There may be additional work and management required to replace these grippers if they fail. Additionally, organic inconsistencies with the spiders will yield inaccurate results. Not all wolf spiders develop the same, so gripping force and leg contraction can vary between grippers.
There are moral implications behind euthanizing spiders for robotics. The ethical boundaries that necrobotics push in the pursuit of biohybrid systems raise concerns, as opponents say it may lead to the hybridization of mammals and is intrusive to nature. Proponents respond that repurposing dead animals has been human practice for millennia and that necrobotics should be pursued to advance science.
See also
3D bioprinting
Biomedical engineering
Blood substitute
Remote control animal
Soft robotics
References
Robotics
Undead
Biorobotics | Necrobotics | [
"Engineering"
] | 1,336 | [
"Robotics",
"Automation"
] |
71,410,175 | https://en.wikipedia.org/wiki/Simple%20homotopy%20theory | In mathematics, simple homotopy theory is a homotopy theory (a branch of algebraic topology) that concerns with the simple-homotopy type of a space. It was originated by Whitehead in his 1950 paper "Simple homotopy types".
See also
Whitehead torsion
References
Further reading
A lecture by J. Lurie.
Homotopy theory
Equivalence (mathematics) | Simple homotopy theory | [
"Mathematics"
] | 78 | [
"Topology stubs",
"Topology"
] |
77,330,501 | https://en.wikipedia.org/wiki/NGC%207713 | NGC 7713 is a barred spiral galaxy with extensive Hubble-type SBcd star-forming regions that is located in the constellation Sculptor in the southern sky. It is estimated to be 31 million light-years from the Milky Way and about 40,000 light-years in diameter. It was discovered by John Herschel on October 4, 1836.
One supernova has been observed in NGC 7713: SN 1982L (type II, mag. 16) was discovered by Marina Wischnjewsky on 21 July 1982.
See also
List of NGC objects (7001–7840)
References
7713
Barred spiral galaxies
Discoveries by John Herschel
Sculptor (constellation) | NGC 7713 | [
"Astronomy"
] | 138 | [
"Constellations",
"Sculptor (constellation)"
] |
77,330,647 | https://en.wikipedia.org/wiki/Culture%20of%20extraterrestriality | A culture of extraterrestriality is the cultural imagination and description of otherworldlyness, alienness or outright outer space, characterizing the other through extraterrestrial space, beyond mere extraterritoriality or periphery, being the space that is imagined or described as extraterrestrial, or simply any space outside a described land.
It creates conditions of extraterrestrialness, spatially set apart otherness, unlike any othered cohabiting entity.
Extraterrestriality has been a feature of many past and contemporary cultures. Politically it has been an element of utopianism and colonialism, particularly its formation, colonies being the product in extraterrestrial space. Such histories have informed contemporary cultures of extraterrestriality, informing the prospecting of space exploration and the reception of its findings, particularly for space colonization and the search for extraterrestrial life. Colonialism was associated with extraterrestrial space already in the first half of the 17th century when John Wilkins suggested in A Discourse Concerning a New Planet that future adventurers like Francis Drake and Christopher Columbus might reach the Moon, and people to live there.
See also
Extraterrestrials in fiction
Search for extraterrestrial intelligence
Potential cultural impact of extraterrestrial contact
Expatriate
Anthropocentrism
References
Search for extraterrestrial intelligence
Space colonization
Extraterrestrial life
Cultural anthropology | Culture of extraterrestriality | [
"Astronomy",
"Biology"
] | 288 | [
"Biological hypotheses",
"Extraterrestrial life",
"Astronomical controversies",
"Hypothetical life forms"
] |
77,331,815 | https://en.wikipedia.org/wiki/Generalized%20space | In mathematics, a generalized space is a generalization of a topological space. Impetuses for such a generalization comes at least in two forms:
A desire to apply concepts like cohomology for objects that are not traditionally viewed as spaces. For example, a topos was originally introduced for this reason.
A practical need to remedy the deficiencies that some naturally-occurring categories of spaces (e.g., ones in functional analysis) tend not to be abelian, a standard requirement to do homological algebra.
Alexander Grothendieck's dictum says a topos is a generalized space; precisely, he and his followers write in exposé 4 of SGA I:
However, William Lawvere argues in his 1975 paper that this dictum should be turned backward; namely, "a topos is the 'algebra of continuous (set-valued) functions' on a generalized space, not the generalized space itself."
A generalized space should not be confused with a geometric object that can substitute the role of spaces. For example, a stack is typically not viewed as a space but as a geometric object with a richer structure.
Examples
A locale is a sort of a space but perhaps not with enough points. The topos theory is sometimes said to be the theory of generalized locales.
Jean Giraud's gros topos, Peter Johnstone's topological topos, or more recent incarnations such as condensed sets or pyknotic sets. These attempt to embed the category of (certain) topological spaces into a larger category of generalized spaces, in a way philosophically if not technically similar to the way one generalizes a function to a generalized function. (Note these constructions are more precise than various completions of the category of topological spaces.)
References
Lawvere, Categories of spaces may not be generalized spaces as exemplified by directed graphs
Mathematical terminology
Topological spaces | Generalized space | [
"Mathematics"
] | 382 | [
"Mathematical structures",
"Space (mathematics)",
"Topological spaces",
"Topology stubs",
"Topology",
"nan"
] |
77,332,489 | https://en.wikipedia.org/wiki/Bluefors | Bluefors is a Helsinki-based company specializing in cryogenic products used in several high-tech industries. Cryogenic solutions are integral to advancements in quantum computing and scientific research. The company offers cryogenic systems, including dilution refrigerators and cryocoolers, which are essential for applications requiring ultra-low temperatures. Cryocoolers are for instance a requirement for today’s superconducting qubits to function.
In response to increasing global demand, the company has expanded its operations. Notable acquisitions include Cryomech in the USA and Rockgate in Japan. Bluefors also have a laboratory in Delft, the Netherlands.
References
Companies based in Helsinki
Companies with year of establishment missing
Cryogenics | Bluefors | [
"Physics"
] | 148 | [
"Applied and interdisciplinary physics",
"Cryogenics"
] |
77,333,569 | https://en.wikipedia.org/wiki/Benjamin%20Pike%20Jr. | Benjamin Pike Jr. (1809May 7, 1864) was a businessman and manufacturer of philosophical and optical instruments. He was the eldest son of Benjamin Pike Sr., whom he joined in business from 1831-1841 under the name Benjamin Pike & Son, before going on to create his own successful firm.
Early life
Benjamin Pike Jr. was born into an English immigrant family in New York City, New York, in 1809, as the son of an optician, Benjamin Pike Sr., who immigrated from the United Kingdom to establish his own optical, scientific, and engineering business in New York, Benjamin Pike Sr. Very little is known about Pike's early life, but it is known he grew up in the Pike family home on North Moore Street, Manhattan, as did his siblings. It is presumed that he studied to be an optician like Pike Sr.
Career
Benjamin Pike & Sons
Records show that in 1831, Pike Jr. joined his father in business, and in order to represent the presence of his son at the firm, it was renamed Benjamin Pike & Son. However, this name would go on to change quite frequently as family members came and went from the business. For example, Daniel Pike joined his brother and father in 1839, and as a result, the business was renamed Benjamin Pike & Sons.
By 1840, the firm was viewed in high regard by patrons and experts alike, with Benjamin Pike & Sons going on to win a Silver Medal at the Fifth Annual Fair of the Mechanics' Institute, being commended for their "surveying and drawing instruments". The Thirteenth Annual Fair of the American Institute would mark another victory for the firm after receiving a second place Diploma for "specimens of surveyors compasses and levels, beautiful finish"
Benjamin Pike Jr. & Co
In 1843, Benjamin Jr. separated from his family's business and formed his own firm, viewed in similarly high regard by the general public known simply as Benjamin Pike Jr. & Co., located at 294 Broadway, which also largely served as his family's home until 1858. Benjamin Jr. had evidently learned the field extremely well as he won countless awards for both the quality and use of his many instruments including three silver medals at American Institute Fairs shortly after going into business. Two of which were for his remarkably "superior air pumps" and one other for his innovative "electro-magnetic apparatus". It was again at the American Institute Fairs that he would win two diplomas that demonstrated his firm's proficiency in both purely mathematical and scientific instruments.
It is here where both Pike Jr.'s optical knowledge and marketing genius propelled his business to new heights through the 1840s through both innovative strategy and market expansion. Rather than simply restricting himself to the market of New York City and those who physically came to his Manhattan firm, Pike created and twice published a massive catalog of over 750 items, in 1848 and in 1856, both fitted with illustrations, engravings, and lengthy descriptions of countless scientific instruments manufactured by his company from telescopes to spectacles. This marketing innovation was not only revolutionary for his business but for the entire scientific world and the diaspora of its knowledge as a whole. It was regarded as the most comprehensive collection of philosophical instruments to ever be conceived that acted as a near-universal catalog of countless devices and scientific products of the age. Moreover, it was in these catalogs that Pike took the opportunity to further emphasize the quality of his products and the innovative and modern nature of his designs that incorporated all the finest aspects of the age's contemporary science and engineering. He further wished to sway the favor of the United States' growing scientific community and shift their consumption from traditionally European instruments to those of his own firm, and in this goal, he largely succeeded. Hence orders would flow in from all across the nation and even parts of Europe, which brought Pike and his company to new heights of fame and prestige. He then massively expanded his business by demolishing and rebuilding a larger version of his store at the same address in 1850 to accommodate the new influx of customers. Leading to the further growth and development of the market reach of his firm as word spread of its utmost quality.
In addition, his depictions and descriptions were so robust and unprecedented, in fact, that his engravings were used commonly for more than a century for analysis of both period and contemporary counterparts of scientific instruments. By the early 20th century his work had become a fundamental basis for scientific demonstration and description in both professional and scholastic environments.
With such a quantity of both patrons and corresponding fame, the Pike family desired an escape from the busy and crowded life of the city where they had been living on the upper floors of their shop for over a decade. So using the vast riches collected as a result of their massive surge in business, Pike constructed an $85,000 built a 27-room mansion in Northern Queens in what is today Astoria, New York. He was seen here in the 1860 U.S. Census, and despite his famous optical firm, Pike had his occupation listed as a farmer. The home was later sold to William Steinway of the piano-making Steinway family in 1870 after the death of Benjamin Pike Jr., and is today known as the Steinway Mansion.
Personal life
Pike married Frances Matilda Hope on April 14, 1838, with whom he had a son and two daughters.
Death
Pike died suddenly and without known cause on May 7th, 1864, in Astoria, New York, around the age of 53. His widow subsequently sold the mansion, which it would be bought by William Steinway in 1870. It is unknown where Pike's wife and children moved after this.
According to directories, the Pike Jr. firm was permanently closed shortly after.
See also
Steinway Mansion
References
Further reading
1809 births
1864 deaths
People from New York City
American scientific instrument makers
American opticians
Telescope manufacturers
19th-century American businesspeople | Benjamin Pike Jr. | [
"Astronomy"
] | 1,177 | [
"Telescope manufacturers",
"People associated with astronomy"
] |
77,333,746 | https://en.wikipedia.org/wiki/RNU4-2%20syndrome | RNU4-2 Syndrome or ReNU syndrome is a neurodevelopmental disorder caused by de novo variants in the human gene RNU4-2, which encodes an RNA component of the major spliceosome. It is characterized by hypotonia, global developmental delay, severely impaired intellectual development with poor or absent speech, delayed walking or inability to walk, feeding difficulties with poor overall growth, dysmorphic facial features, and brain anomalies, including ventriculomegaly.
RNU4-2 / ReNU syndrome is one of the most prevalent monogenic neurodevelopmental disorders, with variants in RNU4-2 estimated to account for around 0.4% of all neurodevelopmental disorders. The syndrome is an autosomal dominant genetic disorder caused by de novo variants in RNU4-2, a gene on chromosome 12, which encodes the small nuclear RNA (snRNA) U4. U4 is a component of the major spliceosome, a complex of proteins and non-coding RNAs that is necessary for RNA splicing. Most cases of RNU4-2 / ReNU syndrome are explained by a 1-bp insertion (n.64_65insT, NR_003137.2), which is thought to disrupt the interactions of snRNA U4 with the snRNA U6, affecting the stability of the ACAGAGA loop of U6 sRNA which binds 5' splice sites and induces splicing after U4-U6 unwinding. Disrupted splicing, in particular a change in 5' splice site usage, has been reported in individuals with variants in RNU4-2.
The genetic etiology of RNU4-2 / ReNU syndrome was first described in a preprint in April 2024. It was subsequently published by two research teams independently, both who used data collected by Genomics England. One team, led by the English statistician Daniel Greene working at the Icahn School of Medicine at Mount Sinai, used a Bayesian analysis. The other team involved a global collaboration led by Yuyang Chen and Nicola Whiffin of the University of Oxford.
Neurodevelopmental disorder with hypotonia, brain anomalies, distinctive facies, and absent language (NEDHAFA) was a suggested name for this syndrome, however, ReNU syndrome (pronounced 'renew') was chosen through a collaboration between researchers and the families of those impacted by variants in RNU4-2. The name symbolises that this diagnosis “renews” hope for a brighter future for all those affected.
References
Medicine
Further reading | RNU4-2 syndrome | [
"Biology"
] | 558 | [
"Medicine"
] |
77,335,668 | https://en.wikipedia.org/wiki/Katherine%20Elkins | Katherine Elkins is professor of humanities and comparative literature and faculty in Computing at Kenyon College.
Early life
Elkins attended Yale as an undergraduate, then completed a Ph.D. at UC Berkeley. She is the niece of Henry Elkins.
Teaching
Elkins is a professor of comparative literature and humanities in the Integrated Program for Humane Studies (IPHS) and faculty in Computing at Kenyon College. She is a founding co-director of the KDH lab and co-created the first human-centered artificial intelligence curriculum launched in 2016 at Kenyon College as the director of IPHS. She has mentored and co-authored hundreds of student ML/AI research projects in the humanities, arts and social sciences that have been downloaded almost 60,000 times worldwide as of September 2024. Her recorded lectures with The Modern Scholar on The Modern Novel (2021) and The Giants of French Literature (2020) are tailored to broader public audiences via Amazon's Audible.com.
Research
Elkins is best known for her pioneering work on interdisciplinary artificial intelligence in literature, narrative, affective computing and the ethics of AI. Her book The Shapes of Stories, published by Cambridge University Press in 2022, provided a comprehensive methodology for using diachronic sentiment analysis to analyze the emotional aspects of plot across dozens of literary classics using SentimentArcs. This method has been used to analyze narrative in diverse forms including literature, translations, TV scripts, end of life medical narratives, and the evolution of social media narratives for elections and economic crisis.
She presented the first transdisciplinary AI research at leading academic conferences including the Modernist Studies Association in October 2019, The International Society for the Study of Narrative in March 2020 and the Modern Language Association Conference in January 2021. Elkins was an early advocate for incorporating AI in literary studies with co-authored essays in The Journal of Cultural Analytics in September 2020 and Narrative in January 2021. More recently she focused on how AI redefines writing, creativity, authorship, translations of literature, eXplainable AI, and the future of the academic field. Her collaborative position paper addressing the risks and benefits of open-source AI was selected for oral presentation at ICML in July 2024.
Elkins traditional scholarship includes essays on Plato, Virginia Woolf, Franz Kafka, Marcel Proust, and William Wordsworth. In 2001 she won the A. Owen Aldridge Prize in Comparative Literature for an essay on Charles Baudelaire. She edited Philosophical Approaches to Proust’s In Search of Lost Time, which brings together essays by leading international Proust scholars, with Oxford University Press in 2022.
Speaking
Elkins is one of the leading women speaking widely on interdisciplinary AI. As early as 2019, she publicly advocated integrating AI into traditional humanities curriculum with a keynote address at the Ohio State University. She gave the Meredith-Donovan lecture at Mount Saint Mary's University in 2023, featured AI Working Group lecture at Wofford College, and presentation at the Stories that Win Symposium at Washington University in 2024. Elkins gives keynotes on the intersection of AI, digital humanities, education, and the future of work. Most recently, in the summer-fall of 2024, these included keynotes at Carleton College's Day of Digital Humanities, Lafayette College AI Literacy Across the Curriculum, and Austin College's A.J. Carlson Lecture.
Elkins has been a co-panelist on interdisciplinary AI conversations with thought leaders from diverse fields. She discussed language, epistemology and the ethics of AI with Ned Block, Francesca Rossi, and Dennis Yi Tenen in October 2022. Elkins debated AI generative art with co-panelist Boris Eldagsen (winner of Sony World Photography Award 2023) and Shane Balkowitsch on Al Jazeera in April 2023. She presented her perspectives on emotions at the intersection of AI and literature with experts Rosalind Picard, Joseph LeDoux, and Mabel Berezin. She discussed what gets lost in machine translation on the podcast Merging Minds.
She is the AI industry expert for Bloomberg's new AI Strategy Course launched 2024. She serves as CAIO of HumanCentricLabs emphasizing humane applications of AI in the workplace.
Collaborations
Kenyon College awarded Elkins the senior trustee teaching award In 2014. In March 2024 she was named a principal investigator for NIST's US AI Safety Institute representing the Modern Language Association. She was awarded a Notre Dame-IBM Tech Ethics Lab award in April 2024 to research the ethics and performance of SOTA LLM models to predict criminal recidivism. Elkins has been a member of Meta's Open Innovation AI Research Community since 2023 and will present at the 2024 Conference at Meta's London Office in October.
References
Year of birth missing (living people)
Living people
American academics
Kenyon College faculty
American women academics
Artificial intelligence researchers
American intelligence researchers
Computing and society
Literary scholars
Yale University alumni
University of California, Berkeley alumni | Katherine Elkins | [
"Technology"
] | 1,003 | [
"Computing and society"
] |
77,336,294 | https://en.wikipedia.org/wiki/Grim%20Reaper%20paradox | In philosophy, the Grim Reaper paradox is a paradox involving an infinite sequence of grim reapers, each tasked with killing a person if no reaper has already killed them. The paradox raises questions about the possibility of continuous time and the infinite past (temporal finitism).
The paradox is inspired by J. A. Benardete's paradoxes from the 1964 book Infinity: An Essay in Metaphysics. In fact, various formulations of paradoxes involving beginningless sets, whose members perform a function only if no previous member performs it, are all labelled Benardete Paradoxes. They are examples of supertasks.
The paradox
The paradox supposes there is an infinite sequence of Reapers, each assigned a time to kill a particular person. Each Reaper will only kill this person if no earlier Reaper has already killed them.
It is 12pm, the first Reaper is set to kill the person at 1pm. The second Reaper is set to kill them at 12:30pm, the third at 12:15pm, and so on.
As a consequence of these propositions, the person will certainly be killed by a Reaper before 1pm, however, no individual Reaper can kill them, as there is always an earlier Reaper who would do so first. Therefore, it is impossible that the person survive, but also impossible that any Reaper kills them.
Resolutions and Implications
Discrete time
One solution to the paradox is supposing that time must be discrete rather than continuous. If so, an infinite number of Reapers cannot all have a separate time in which they will kill you, as there are only finitely many "moments" in each period of time. A possible issue with this solution is that the Reaper paradox can take different forms which do not rely upon continuous time. One such example appears in Benardete's book, in which a god throws up a wall if a man travels 1/2 mile, another god throws up a wall after 1/4 mile, another at 1/8 mile, ad infinitum. Discrete time would do nothing to prevent this paradox.
Causal finitism
Another solution is the idea of Causal finitism, which asserts that there cannot be an infinite regress of causes. In other words, every causal chain must have a starting point. Thus, there cannot be an infinite number of Reapers whose actions depend on all previous Reapers. All Benardete paradoxes share this feature of an infinite causal chain, and so are all impossible.
Causal finitism could plausibly imply the discreteness of time, temporal finitism, infinitely large spatial regions, and continuously dense spatial regions, all of which are heavy metaphysical commitments.
The Unsatisfiable Pair Diagnosis
A third potential solution to the Grim Reaper paradox has been suggested, known as the Unsatisfiable Pair Diagnosis (UPD). The UPD asserts that Benardete paradoxes (including the Grim Reaper paradox) are simply logically impossible, and no metaphysical thesis needs to be adopted. In The Form of the Benardete Dichotomy Nickolas Shackel observes that all Benardete Paradoxes involve two conditions:
The linearly ordered set S has no first member
For all x in S, E at x iff E nowhere before x
Shackel shows these statements to be formally inconsistent, they logically cannot both be true. The paradox assumes that some set of items could satisfy both statements, but no set can.
Relevance to theism
According to Pruss, the Grim Reaper paradox provides grounds for thinking that the past is finite, i.e. that there must be a first period of time. This would support the Kalam cosmological argument, backing up the premise that the universe began to exist.
In 2018, Pruss provided a more thorough cosmological argument using causal finitism to motivate a necessary uncaused cause. The argument is as follows:
Nothing has an infinite causal history.
There are no causal loops.
Something has a cause.
Therefore, there is an uncaused cause.
Pruss then adds the following Causal Principle: 5. Every contingent item has a cause. From this the conclusion can be drawn that there is an uncaused cause which exists necessarily. Pruss states that it is still a major task to argue from a necessary first cause to theism.
Whilst The Kalam argument opposes sequences that go infinitely backwards in time, this argument denies all causally backwards-infinite sequences.
Notes
References
Supertasks
Infinity
Philosophical paradoxes | Grim Reaper paradox | [
"Mathematics"
] | 911 | [
"Physical quantities",
"Time",
"Mathematical objects",
"Infinity",
"Philosophy of time",
"Spacetime",
"Supertasks"
] |
77,338,790 | https://en.wikipedia.org/wiki/Motonormativity | Motonormativity (also motornormativity, windshield bias, or car brain) is an unconscious cognitive bias in which the assumption is made that motor car ownership and use is an unremarkable social norm.
Coinage
The term was coined by Swansea University psychologist Ian Walker and colleagues in a 2023 study.
Description and significance
Motonormativity is not a bias confined just to motorists, but is a feature of car-centric societies. Walker has argued that a consequence of motonormative bias is that any attempt to reduce car use is not seen plainly for what it is, but interpreted as an attempt to curtail personal freedom. This effect has been documented not just in famously car dependent North America, but around the world.
Examples
Walker has cited certain road safety campaigns targeting children as an example of motonormativity: by encouraging children to wear brightly coloured clothing to avoid being run over, such campaigns normalize the idea of motor traffic as an accepted danger others must adjust to, in a way which in other contexts would be considered victim blaming.
Motonormativity may affect planning decisions so that, for example, a new hospital is built outside a city even though that makes it less accessible to city dwellers who do not have use of a car.
See also
Normativity
Mode of transport
Transport poverty
References
Further reading
Cognitive biases
Neologisms
2020s neologisms
Transport policy
Transport terminology
Public health | Motonormativity | [
"Physics"
] | 292 | [
"Physical systems",
"Transport",
"Transport policy",
"Transport terminology"
] |
77,339,299 | https://en.wikipedia.org/wiki/3D%20Morphable%20Model | In computer vision and computer graphics, the 3D Morphable Model (3DMM) is a generative technique that uses methods of statistical shape analysis to model 3D objects. The model follows an analysis-by-synthesis approach over a dataset of 3D example shapes of a single class of objects (e.g., face, hand). The main prerequisite is that all the 3D shapes are in a dense point-to-point correspondence, namely each point has the same semantical meaning over all the shapes. In this way, we can extract meaningful statistics from the dataset and use it to represent new plausible shapes of the object's class. Given a 2D image, we can represent its 3D shape via a fitting process or generate novel shapes by directly sampling from the statistical shape distribution of that class.
The question that initiated the research on 3DMMs was to understand how a visual system could handle the vast variety of images produced by a single class of objects and how these can be represented. The primary assumption in developing 3DMMs was that prior knowledge about object classes was crucial in vision. 3D Face Morphable Models are the most popular 3DMMs since they were the first to be developed in the field of facial recognition. It has also been applied to the whole human body, the hand, the ear, cars, and animals.
See also
3D Face Morphable Model
Statistical shape analysis
References
External links
Computer vision
3D computer graphics | 3D Morphable Model | [
"Engineering"
] | 293 | [
"Artificial intelligence engineering",
"Packaging machinery",
"Computer vision"
] |
77,340,280 | https://en.wikipedia.org/wiki/Ring%20star%20problem | The ring star problem (RSP) is a NP-hard problem in combinatorial optimization. In a complete weighted mixed graph, the ring star problem aims to find a minimum cost ring star subgraph formed by a cycle (ring part) and a set of arcs (star part) such that each arc's child node belongs to the cycle and each arc's parent node does not. The costs for the arcs are usually different than the cycle's costs. The cycle must contains at least one node which is called the depot or the root.
RSP is a generalization of the traveling salesman problem. When the costs of the arcs are infinite and the ring contains all nodes, the RSP reduces to TSP. Some applications of RSP arise in the context of telecommunications, transports or logistics.
Exact formulations
RSP was first formulated in 1998. The first MILP for solving RSP was introduced in 2004 alongside valid inequalities that improve the formulation. Several exact formulations have since been introduced in order to solve the Ring star problem such as a graph-layers based ILP and a st-chains formulation.
Variants of the ring star problem
Many variants of the ring star problem have been studied since 2006.
The capacitated m-ring star problem (2006)
The multi-depot ring star problem (2010)
The non-disjoint m-ring star problem (2014)
The survivable ring star problem (2024)
Heuristics
The first heuristic for RSP, a general variable neighborhood search has been introduced in order to obtain approximate solutions more quickly. In 2013, an evolutionary algorithm also approximates RSP. In 2020, an ant colony optimization heuristic outperforms the evolutionary algorithm heuristic.
References
NP-hard problems
Complexity classes | Ring star problem | [
"Mathematics"
] | 367 | [
"NP-hard problems",
"Mathematical problems",
"Computational problems"
] |
77,340,579 | https://en.wikipedia.org/wiki/Marco%20Aiello | Marco Aiello (born September 3, 1972) is an Italian-German computer scientist, author and professor.
Early life and professional career
In 2002, Aiello obtained his PhD on modal logics of space with applications to document understanding and image retrieval under the supervision of Johan van Benthem and Arnold Smeulders. The work culminated in the collective work published as the Handbook of Spatial Logic. When he moved to the University of Trento in 2002, he became interested in service-oriented computing and the problem of service composition.
He spent 2017 on sabbatical leave at the University of Macquarie, Sydney, to work on his book about the Web. Inspired by a quote from Alan Kay, the book is a report and interpretation of the history of the Web, analyzing its strengths, weaknesses, and reasons for success.
In 2018, he accepted the offer of the position of professor and head of the service computing department at the Institute for Architecture of Application Systems (IAAS) at the University of Stuttgart. During his tenure at Stuttgart, Aiello's research focused on AI Planning for service composition, AI Planning for robot navigation, topological considerations in smart grids, and green ICT with particular attention to data center operations, microgrids, and electric vehicle interactions.
As an author
2003- Reasoning about space: the modal way
2007- Handbook of Spatial Logics
2010- Requirements and tools for variability management
2013- Energy Intelligent Buildings based on User Activity: a Survey
2015- HTN planning: Overview, comparison, and beyond
2016- From the grid to the smart grid, topologically
2017- Metrics for sustainable data centers
2018- The Web Was Done by Amateurs
2018- Personalized physical activity coaching: a machine learning approach
2023- Service-Oriented Computing
References
1972 births
Living people
Computer scientists | Marco Aiello | [
"Technology"
] | 363 | [
"Computer science",
"Computer scientists"
] |
78,756,195 | https://en.wikipedia.org/wiki/LL%20Aquarii | LL Aquarii is an eclipsing binary star system in the equatorial constellation of Aquarius, abbreviated LL Aqr. At peak brightness it has a combined apparent visual magnitude of 9.23, which is too dim to be visible to the naked eye. Based on parallax measurements, it is located at a distance of approximately 447 light years from the Sun. The system is drifting closer with a heliocentric radial velocity of about −10 km/s.
Observations
In 1996, this star was found to be an Algol-type eclipsing binary based on photometric observations made with the Hipparcos space observatory. It was assigned the variable-star designation LL Aqr in 1999. This is a detached system forming a double-lined spectroscopic binary. In 2004, a more extensive light curve showed an eccentric orbit with a period of 20.1784 days. During the primary eclipse, the system dropped to magnitude 9.86, while the secondary eclipse showed a magnitude of 9.59. The first orbital elements were published in 2008, showing an orbital eccentricity of 0.3095 with a mass ratio of 0.86. Stellar models indicated the stars are near the mid point of their main sequence lifetimes.
The more massive member of the system, the primary component, has a stellar classification of F9 V, matching an F-type main-sequence star. It has 19.5% more mass than the Sun and a 32% greater girth. This star is radiating 2.15 times the luminosity of the Sun from its photosphere at an effective temperature of around 6,080 K. It is spinning with a projected rotational velocity of . The metallicity, or abundance of elements with mass greater than helium, is very nearly Sun-like.
The secondary component is considered a solar twin, which means its properties are close to Sun-like. It is a G-type main-sequence star with a class of G3 V. Neither member of the system shows signs of stellar activity, being slowly rotating and not emitting X-rays. Tidal effects between the two stars is negligible; they have an orbital separation of 40.7 times the radius of the Sun.
References
Further reading
F-type main-sequence stars
G-type main-sequence stars
Solar twins
Algol variables
Aquarius (constellation)
Durchmusterung objects
213896
111454
Aquarii, LL | LL Aquarii | [
"Astronomy"
] | 498 | [
"Constellations",
"Aquarius (constellation)"
] |
78,760,630 | https://en.wikipedia.org/wiki/Asandeutertinib | Asandeutertinib is an investigational new drug that is being evaluated for the treatment of cancer. It is an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) with antineoplastic properties. Developed by TYK Medicines, this small molecule drug is currently being investigated for the treatment of non-small cell lung cancer (NSCLC), particularly in patients with EGFR mutations.
References
Antineoplastic drugs
Acrylamides
Anilines
Deuterated compounds
Diamines
Indoles
Methoxy compounds
Pyrimidines
Dimethylamino compounds | Asandeutertinib | [
"Chemistry"
] | 128 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
78,760,778 | https://en.wikipedia.org/wiki/Ateganosine | Ateganosine is a telomerase inhibitor and apoptosis inducer currently under investigation for the treatment of various cancers, including non-small cell lung cancer (NSCLC).
References
Antineoplastic drugs
Alcohols
Purines
Tetrahydrofurans
Diols | Ateganosine | [
"Chemistry"
] | 60 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
78,761,652 | https://en.wikipedia.org/wiki/Koyama%20Shisei | was a Japanese physician and vaccinologist. He also used the name .
Koyama's reputation was such that he was compared with other outstanding scientists of his time, as in the phrase, .
Biography
He was born in 1807 near village in rural Kii Province to a jizamurai family. When he was young, he traveled to Kyoto to study with his elder brother , but Fumiaki in 1822. In 1823, he began studying Confucianism under his brother's teacher , and medical science under , a physician to the Imperial Court. He also studied herbal medicine and kanpō. Eventually, Koyama opened his own medical practice on Karasuma Street.
At the beginning of the 19th century, the Balmis Expedition introduced Edward Jenner's technique of using cowpox to inoculate patients against smallpox to Qing China. Hearing of this, Koyama obtained from Takagai Ki'en a copy of the Chinese book Yin dou lue (引痘略) written by Qiu Xi (邱 熺) which contained an explanation of Jennerian inoculation. Koyama's activities are primarily responsible for this information becoming widely available in Japan.
During the Tenpō period (1830–1844), an epidemic of smallpox ravaged Koyama's native Kii Province. After he learned that his nephew's entire family had died of smallpox in 1835, he immersed himself in research to discover a way to combat the disease. Koyama sold almost all of his personal belongings, including his family swords, in order to raise money to buy cattle for his research. The cattle were used to cultivate cowpox samples.
In 1849, Koyama successfully tested Japan's first Jennerian smallpox vaccine, .
Koyama died in Kyoto in 1862.
See also
Kuwata Ryūsai (1811-1868)
Fukase Yōshun
Isao Arita
Further reading
References
1807 births
1867 deaths
19th-century Japanese physicians
Japanese medical researchers
Samurai
Vaccinologists | Koyama Shisei | [
"Biology"
] | 405 | [
"Vaccination",
"Vaccinologists"
] |
78,761,776 | https://en.wikipedia.org/wiki/Transition%20metal%20sulfito%20complex | Transition metal sulfito complexes are coordination compounds containing sulfite (SO32-) as a ligand. The inventory is large. Few sulfito complexes have commercial applications, but sulfite is a substrate for the molybdoenzyme sulfite oxidase.
Bonding modes
In principle, sulfite can bond to metal ions via S or O. To some extent, the sulfito ligand resembles nitrito (), which can bind through N or O. Monodentate, S-bonded sulfites are more common than O-bonded sulfito ligands. S-Bonded sulfite is a soft ligand with a strongly trans labilizing effect as indicated by the rapid aquation of to give .
In some cases, sulfite serves as a bridging ligand forming M-SO2-O-M’ linkages.
Examples
(tetren = )
(M = Rh, Co, en = ethylenediamine)
Complexes with modified sulfito ligands
Being dibasic, sulfito ligands are susceptible to O-alkylation and O-protonation. Some examples:
References
Ligands
Sulfites | Transition metal sulfito complex | [
"Chemistry"
] | 246 | [
"Ligands",
"Coordination chemistry"
] |
78,762,275 | https://en.wikipedia.org/wiki/NACOS | Nigeria Association of Computing Students (NACOS) is the umbrella body for students studying computer science, computer engineering, information systems, cyber security, software engineering, telecommunications engineering, and all IT-related courses in Nigeria. NACOS was formed in 2020 to replace the Nigeria Association of Computer Science Students(NACOSS) established in 1993.
As of 2023, NACOS holds a student membership database of approximately One Million (1,000,000) members, spread across over 250 local chapters in tertiary institutions, including universities, polytechnics, and colleges of education. These chapters are located across the six geo-political zones of Nigeria, making NACOS the largest and most organized student body in Africa.
History
The Nigerian Association of Computer Science Students (NACOSS) was founded in July 1993 by a group of students with the support of the Nigerian Computer Society (NCS), its parent body. NACOSS was established to represent students in computer-related disciplines across Nigeria's tertiary institutions, including Computer Science, Computer Engineering, and Information Technology.
By 2012, NACOSS had grown to include over 250,000 registered members in more than 150 local chapters spanning universities, polytechnics, and colleges of education across Nigeria's six geo-political zones. Its activities focus on capacity building, professional development, and fostering entrepreneurship in Information Technology.
In 2020, NACOSS transitioned into the Nigeria Association of Computing Students (NACOS) to reflect the broader scope of computing disciplines.
Institutional presence
References
Information technology organizations
Computer science organizations
Non-profit organizations based in Nigeria
Student organizations established in 2020
Student organizations in Africa | NACOS | [
"Technology"
] | 325 | [
"Computer science",
"Information technology organizations",
"Information technology",
"Computer science organizations"
] |
78,762,546 | https://en.wikipedia.org/wiki/Darboux%20cyclide | A Darboux cyclide is an algebraic surface of degree at most 4 that contains multiple families of circles. Named after French mathematician Gaston Darboux who studied these surfaces in 1880, Darboux cyclides are a superset of Dupin cyclides and quadrics. These surfaces have applications in architectural geometry and computer-aided geometric design (CAGD).
Definition
A Darboux cyclide is defined as a surface whose equation in a Cartesian coordinate system has the form
where is a constant, is a polynomial of degree 1, and is a polynomial of degree at most 2 with coefficients that do not vanish simultaneously. If the left-hand side of this equation factors into non-constant polynomials with complex coefficients, the Darboux cyclide is called a reducible cyclide. A reducible cyclide either splits into a union of spheres/planes or degenerates to a curve in .
History
The mathematical study of Darboux cyclides began with Ernst Kummer's work in 1865, followed by significant contributions from Gaston Darboux in 1880. Julian Coolidge provided a comprehensive discussion of these surfaces in his 1916 monograph. After a period of reduced interest, geometers rediscovered these surfaces in the late 20th century, particularly due to their remarkable property of carrying multiple families of circles.
Properties and applications
Darboux cyclides can carry up to six families of real circles. That is, these circles lie entirely within the surface—they are contained within it as part of its geometric structure. These circle families manifest in two distinct types. The first type consists of paired families, where two families of circles are related such that any sphere through a circle of one family intersects the cyclide in a circle of the other family. The second type comprises single families, which arise when the cyclide is generated as a canal surface (the envelope of a one-parameter family of spheres).
A Möbius sphere (also known as an M-sphere) is the set given by the equation , where do not vanish simultaneously. Darboux cyclides can exhibit symmetry with respect to up to five pairwise orthogonal Möbius spheres, though at least one of these spheres must be imaginary; that is, one M-sphere has no real points at all.
Smooth Darboux cyclides can be classified topologically into three distinct categories: sphere-like surfaces, toruslike surfaces, and configurations consisting of two spheres.
In architectural geometry, Darboux cyclides have been applied in the rationalization of freeform structures–the process of taking a complex freeform architectural design and breaking it down into parts that can be manufactured and built while maintaining the designer's artistic intent. Their ability to carry multiple families of circles makes Darboux cyclides particularly useful in the design of circular arc structures and the creation of panels and supporting elements in architectural surfaces. The geometric properties of Darboux cyclides allow for efficient manufacturing processes and structural stability in architectural designs.
See also
Dupin cyclide
Möbius geometry
Algebraic surface
Architectural geometry
References
Algebraic surfaces
Differential geometry
Architectural elements
Computer-aided design | Darboux cyclide | [
"Technology",
"Engineering"
] | 640 | [
"Computer-aided design",
"Design engineering",
"Building engineering",
"Architectural elements",
"Components",
"Architecture"
] |
78,764,058 | https://en.wikipedia.org/wiki/C/2012%20L2%20%28LINEAR%29 | C/2012 L2 (LINEAR) is a non-periodic comet that was discovered on 1 June 2012 by LINEAR. Preliminary calculations of its orbit by Maik Meyer noted a striking similarity with that of C/1785 A1 (Messier–Mechain), however it is purely a coincidence rather than the return of the latter comet. It passed perihelion in May 2013.
Discovery and observations
The comet was discovered as a 19.4-magnitude object from photographs taken by the Lincoln Near-Earth Asteroid Research survey on the morning of 1 June 2012. Five days after discovery, Maik Meyer noted that the preliminary orbit of this comet was initially similar to that of C/1785 A1, however he later concluded that these comets were unrelated from one another. Its aphelion distance suggested it may have been a dynamically new object that originated from the inner regions of the Oort cloud, therefore imaging polarimetry of the comet was conducted to further study the composition of these objects.
References
External links
C/2012 L2 (LINEAR) from the IRIDA Observatory, 4 April 2013
Non-periodic comets
Comets in 2012
Comets in 2013
Oort cloud | C/2012 L2 (LINEAR) | [
"Astronomy"
] | 234 | [
"Astronomical hypotheses",
"Oort cloud",
"Astronomy stubs",
"Comet stubs"
] |
78,764,511 | https://en.wikipedia.org/wiki/C/2012%20X1%20%28LINEAR%29 | Comet LINEAR, formal designation C/2012 X1, is a non-periodic comet that was observed telescopically from 2012 to 2015. It produced a powerful outburst on 21 October 2013, which raised its brightness 100 times its expected magnitude from 12 to 8.5 for several months.
Discovery and observations
An asteroid-like object with an apparent magnitude of 19.4 was spotted with cometary activity from images taken by the Lincoln Near-Earth Asteroid Research survey on the night of 8 December 2012.
From April 2014 onwards, the comet slowly faded away as it made its way back to the outer Solar System. It was last observed from Australia as a 20th-magnitude object about from the Sun on 9 December 2015.
References
External links
Non-periodic comets
20121208
Discoveries by LINEAR
Comets in 2014
Comets in 2012 | C/2012 X1 (LINEAR) | [
"Astronomy"
] | 165 | [
"Astronomy stubs",
"Comet stubs"
] |
78,765,540 | https://en.wikipedia.org/wiki/Bimokalner | Bimokalner is an investigational new drug under evaluation for preventing and treating hearing loss caused by cisplatin treatment. It is a voltage-gated potassium channel agonist targeting Kv7.4 and is being developed by Acousia Therapeutics GmbH.
References
Amides
Bicycloalkanes
Organosulfur compounds
Phenyl compounds
Sulfur fluorides | Bimokalner | [
"Chemistry"
] | 77 | [
"Pharmacology",
"Organosulfur compounds",
"Functional groups",
"Medicinal chemistry stubs",
"Organic compounds",
"Pharmacology stubs",
"Amides"
] |
78,765,706 | https://en.wikipedia.org/wiki/Brimarafenib | Brimarafenib is an investigational new drug that is being evaluated for the treatment of cancer. It targets the proto-oncogene BRAF with activating mutations BRAF mutations (such as V600E), non-V600 BRAF mutations, and RAF fusions.
It is being developed by MapKure, LLC, a joint venture between SpringWorks Therapeutics and BeiGene.
References
Antineoplastic drugs
Benzofurans
Ethers
Fluorobenzenes
Naphthyridines
Phenols
Piperidinones
Ureas | Brimarafenib | [
"Chemistry"
] | 117 | [
"Pharmacology",
"Functional groups",
"Medicinal chemistry stubs",
"Organic compounds",
"Ethers",
"Pharmacology stubs",
"Ureas"
] |
78,765,811 | https://en.wikipedia.org/wiki/Camibirstat | Camibirstat is an investigational new drug that is being evaluated for the treatment of cancer. It is a small molecule that acts as a selective inhibitor of SMARCA2 and SMARCA4, which are key components of the SWI/SNF chromatin remodeling complex.
It is being developed by Foghorn Therapeutics.
References
Alpha-Amino acids
Amides
Ethers
Morpholines
Pyridines
Pyrroles
Sulfonamides
Thiazoles | Camibirstat | [
"Chemistry"
] | 104 | [
"Pharmacology",
"Functional groups",
"Medicinal chemistry stubs",
"Organic compounds",
"Ethers",
"Pharmacology stubs",
"Amides"
] |
78,765,897 | https://en.wikipedia.org/wiki/Claziprotamide | Claziprotamide is an investigational new drug that is being evaluated for the treatment of rare metabolic disorders such as pantothenate kinase-associated neurodegeneration (PKAN) and neurodegeneration with brain iron accumulation (NBIA). It acts as a positive allosteric modulator (PAM) of pantothenate kinases 1 and 3 (PANK1 and PANK2) which are critical for coenzyme A biosynthesis and cellular metabolism.
References
Carboxamides
Cyclopropanes
Fluorobenzenes
Piperazines
Pyridazines | Claziprotamide | [
"Chemistry"
] | 129 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
78,765,997 | https://en.wikipedia.org/wiki/NUTS%20statistical%20regions%20of%20Ukraine | The Nomenclature of Territorial Units for Statistics (NUTS) is a geocode standard for referencing the subdivisions of Ukraine for statistical purposes. The NUTS standard is instrumental in delivering the European Union's Structural Funds. The NUTS code for Ukraine is UA and a hierarchy of three levels is established by Eurostat. Below these is a further levels of geographic organisation - the local administrative unit (LAU). In Ukraine, the LAUs are Hromada. As a candidate country of the European Union, Ukraine (UA) is in the process of being included in the Nomenclature of Territorial Units for Statistics (NUTS).
Overall
NUTS Levels
Local administrative units
Below the NUTS levels, the two LAU (Local Administrative Units) levels are:
NUTS codes
Sources
STATISTICAL CLASSIFICATION OF TERRITORIAL UNITS OF UKRAINE (NUTS-UA)
NUTS-3 of Ukraine
NUTS Regions EUROSTAT
External
Territorial units in Russia, Ukraine, Belarus and Moldova and NUTS classification
Proposed Constitution UA Macroregions
Пропозиція Конституції Макрорегіони України
Ukraine
Nuts | NUTS statistical regions of Ukraine | [
"Mathematics"
] | 230 | [
"Nomenclature of Territorial Units for Statistics",
"Statistical concepts",
"Statistical regions"
] |
78,766,151 | https://en.wikipedia.org/wiki/Crelosidenib | Crelosidenib is an investigational new drug that is being evaluated for the treatment of cancer. It acts as a selective inhibitor of isocitrate dehydrogenase 1 (IDH1), an enzyme that plays a crucial role in cellular metabolism and is frequently mutated in various cancers, including cholangiocarcinoma.
References
Antineoplastic drugs
Acrylamides
Oxazines
Piperazines
Pyrimidines
Cyclopropyl compounds | Crelosidenib | [
"Chemistry"
] | 98 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
78,766,215 | https://en.wikipedia.org/wiki/Dapolsertib | Dapolsertib is an investigational new drug that is being evaluated for the treatment of cancer. It is dual inhibitor of PIM family of serine/threonine protein kinases and mutant forms of FMS-related tyrosine kinase 3 (FLT3) that is being developed by Ryvu Therapeutics SA.
References
Antineoplastic drugs
Benzimidazoles
Bromobenzene derivatives
Nitrobenzenes
Piperidines
Isopropyl compounds | Dapolsertib | [
"Chemistry"
] | 101 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
69,832,190 | https://en.wikipedia.org/wiki/Institute%20of%20Particle%20Physics | The Institute of Particle Physics (IPP) is a Canadian organization that fosters expertise in particle physics research and advanced education. IPP is a nonprofit organization operated by the institutional and individual members for the benefit of particle physics research in Canada.
IPP supported projects can be accessed on the group's website. Currently, the IPP Scientific Council administers the IPP Research Scientist Program. The IPP director and council focus on future planning, advocacy with funding sources, and on its activities in international public relations.
History
The IPP was established in 1971 to administer anticipated funds from the National Research Council Canada to steer the Canadian program working at Fermilab, Argonne National Lab, and SLAC National Accelerator Laboratory. IPP formed a Scientific Council, elected by the membership, to be responsible for the Scientific program and the operation of the Institute.
IPP council vetted projects and advocated within the funding regime and internationally. Eventually, the Natural Sciences and Engineering Research Council (NSERC) developed better communication with, and funding model for, experimental groups, alleviating the need for IPP to directly administer research grant funds.
Community support
Long range planning
An important part of the Institute of Particle Physics’ mission is to coordinate community input for long range planning exercises. This involves solicitations of community input, hosting of town hall meetings where the projects underway and future projects are discussed, and the concerns of the community can be aired. This input results in the preparation of a brief, usually solicited by NSERC, that serves as input to the Subatomic Physics long range planning exercise.
IPP Early Career Theory Fellowship
The Institute of Particle Physics Early Career Theory Fellowship is designed to enable outstanding theory PhD students and postdoctoral researchers to be present for a period at an international university, laboratory, or institute. The purpose of the fellowship is to encourage scientific collaboration between theorists in Canada and those abroad, and also to enhance the career prospects of the junior researcher.
IPP high school teacher awards
The Institute of Particle Physics has supported Canadian high school teachers attending the CERN high school teacher program.
IPP summer student program
The Institute of Particle Physics supports Canadian undergraduate students participating in the CERN summer student program.
References
External links
Official website
1971 establishments in Canada
Particle physics
Science education in Canada | Institute of Particle Physics | [
"Physics"
] | 462 | [
"Particle physics"
] |
69,832,745 | https://en.wikipedia.org/wiki/Zilber%E2%80%93Pink%20conjecture | In mathematics, the Zilber–Pink conjecture is a far-reaching generalisation of many famous Diophantine conjectures and statements, such as André–Oort, Manin–Mumford, and Mordell–Lang. For algebraic tori and semiabelian varieties it was proposed by Boris Zilber and independently by Enrico Bombieri, David Masser, Umberto Zannier in the early 2000's. For semiabelian varieties the conjecture implies the Mordell–Lang and Manin–Mumford conjectures. Richard Pink proposed (again independently) a more general conjecture for Shimura varieties which also implies the André–Oort conjecture. In the case of algebraic tori, Zilber called it the Conjecture on Intersection with Tori (CIT). The general version is now known as the Zilber–Pink conjecture. It states roughly that atypical or unlikely intersections of an algebraic variety with certain special varieties are accounted for by finitely many special varieties.
Statement
Atypical and unlikely intersections
The intersection of two algebraic varieties is called atypical if its dimension is larger than expected. More precisely, given three varieties , a component of the intersection is said to be atypical in if . Since the expected dimension of is , atypical intersections are "atypically large" and are not expected to occur. When , the varieties and are not expected to intersect at all, so when they do, the intersection is said to be unlikely. For example, if in a 3-dimensional space two lines intersect, then it is an unlikely intersection, for two randomly chosen lines would almost never intersect.
Special varieties
Special varieties of a Shimura variety are certain arithmetically defined subvarieties. They are higher dimensional versions of special points. For example, in semiabelian varieties special points are torsion points and special varieties are translates of irreducible algebraic subgroups by torsion points. In the modular setting special points are the singular moduli and special varieties are irreducible components of varieties defined by modular equations.
Given a mixed Shimura variety and a subvariety , an atypical subvariety of is an atypical component of an intersection where is a special subvariety.
The Zilber–Pink conjecture
Let be a mixed Shimura variety or a semiabelian variety defined over , and let be a subvariety. Then contains only finitely many maximal atypical subvarieties.
The abelian and modular versions of the Zilber–Pink conjecture are special cases of the conjecture for Shimura varieties, while in general the semiabelian case is not. However, special subvarieties of semiabelian and Shimura varieties share many formal properties which makes the same formulation valid in both settings.
Partial results and special cases
While the Zilber–Pink conjecture is wide open, many special cases and weak versions have been proven.
If a variety contains a special variety then by definition is an atypical subvariety of . Hence, the Zilber–Pink conjecture implies that contains only finitely many maximal special subvarieties. This is the Manin–Mumford conjecture in the semiabelian setting and the André–Oort conjecture in the Shimura setting. Both are now theorems; the former has been known for several decades, while the latter was proven in full generality only recently.
Many partial results have been proven on the Zilber–Pink conjecture. An example in the modular setting is the result that any variety contains only finitely many maximal strongly atypical subvarieties, where a strongly atypical subvariety is an atypical subvariety with no constant coordinate.
See also
Existential Closedness conjecture
Schanuel's conjecture
Boris Zilber
References
Further reading
Diophantine geometry
Conjectures | Zilber–Pink conjecture | [
"Mathematics"
] | 788 | [
"Unsolved problems in mathematics",
"Mathematical problems",
"Conjectures"
] |
69,832,813 | https://en.wikipedia.org/wiki/Silicon%20quantum%20dot | Silicon quantum dots are metal-free biologically compatible quantum dots with photoluminescence emission maxima that are tunable through the visible to near-infrared spectral regions. These quantum dots have unique properties arising from their indirect band gap, including long-lived luminescent excited-states and large Stokes shifts. A variety of disproportionation, pyrolysis, and solution protocols have been used to prepare silicon quantum dots, however it is important to note that some solution-based protocols for preparing luminescent silicon quantum dots actually yield carbon quantum dots instead of the reported silicon. The unique properties of silicon quantum dots lend themselves to an array of potential applications: biological imaging, luminescent solar concentrators, light emitting diodes, sensors, and lithium-ion battery anodes.
History
Silicon has found extensive use in electronic devices; however, bulk Si has limited optical applications. This is largely due to the vertical optical transition between the conduction band and valence band being forbidden because of its indirect band gap. In 1990, Leigh Canham showed that silicon wafers can emit light after being subjected to electrochemical and chemical dissolution. The light emission was attributed to the quantum confinement effect in the resulting porous silicon. This early work provided a foundation for several different types of silicon nanostructures including silicon nanoparticles (quantum dots), silicon nanowires, silicon nanoshells, silicon nanotubes, silicon aerogels, and mesoporous silicon.
The first reports of silicon quantum dots emerged in the early 1990s demonstrating luminescence from freestanding oxidized silicon quantum dots. Recognizing the vast potential of their unique optical properties, many researchers explored, and developed methods to synthesize silicon quantum dots. Once these materials could be prepared reliably, methods to passivate the surfaces were critical to rendering these materials solution processable and minimize the effects of oxidation. Many of these surface passivation methods draw inspiration from methods that were first developed for silicon wafers and porous silicon. Currently, silicon quantum dots are being commercialized by Applied Quantum Materials Inc. (Canada).
Properties
Silicon quantum dots (SiQDs) possess size-tunable photoluminescence that is similar to that observed for conventional quantum dots. The luminescence is routinely tuned throughout the visible and into the near-infrared region by defining particle size. In general, there are two distinct luminescence bands that dominate silicon quantum dot properties. Long-lived luminescence excited states (S-band, slow decay rate) are typically associated with size-dependent photoluminescence ranging from yellow/orange to the near-infrared. Short-lived luminescent excited states (F-band, fast decay rate) are typically associated with size-independent blue photoluminescence and in some cases nitrogen impurities have been implicated in these processes. The S-band is typically attributed to the size-dependent band gap of the silicon quantum dots. This emission can be tuned from yellow (600 nm) into the infrared (1000 to 1100 nm) by changing the diameter of the silicon quantum dots from about 2 to 8 nm. Some reports also describe the preparation of green-emitting silicon quantum dots prepared by decreasing the size, however, these materials are challenging to isolate and require further development. Silicon quantum dot luminescence may also be tuned by defining their surface chemistry. Attaching different surface species allows tuning of silicon quantum dot luminescence throughout the visible spectrum while the silicon quantum dot dimensions remain unchanged. This surface tuning is typically accompanied by the appearance of nanosecond lifetimes like those seen for F-band luminescence. Silicon quantum dot photoluminescence quantum yields are typically in the range of 10 to 40%, with a handful of synthetic protocols providing values in excess of 70%.
The long-lived excited state of silicon quantum dot S-band luminescence that starkly contrasts photoemission from conventional quantum dots is often attributed to the inherent indirect band gap of silicon and lends itself to unique material applications. Combining long-lived excited states with the biological compatibility of silicon quantum dots enables time-gated biological imaging. The large Stokes shift allows them to convert photons from the ultraviolet range into the visible or infrared range and is particularly beneficial in the design and implementation of luminescent solar concentrators because it limits self-absorption while down converting the light.
Importantly, SiQDs are biologically compatible and do not contain heavy metals (e.g., cadmium, indium, lead). The biological compatibility of these materials has been carefully studied both in vitro and in vivo. During in vitro studies, SiQDs have been found to exhibit limited toxicity in concentrations up to 72 μg/mL in HeLa cells and 30 μg/mL in epithelial-like cells (MDA-MB-231). In vivo studies assessing biological compatibility of SiQDs undertaken in mice and monkeys (rhesus macaques) found "no signs of toxicity clearly attributable to SiQDs." In bacteria, SiQDs have been shown to be less toxic than both CdSe and CdSe/ZnS quantum dots.
Synthesis
Synthesis methods
Silicon quantum dots can be synthesized using a variety of methods, including thermal disproportionation of silicon suboxides (e.g., hydrogen silsesquioxane, a silsesquioxane derivative), and laser and plasma-induced decomposition of silane(s). These methods reliably provide high quality SiQDs exhibiting size/band gap dependent (S-band) photoluminescence. Top-down methods, such as laser ablation and ball-milling have also been reported. Several solution-based methods have also been presented that often result in materials exhibiting F-band luminescence. Recently, it has been determined that some of these methods do not provide silicon quantum dots, but rather luminescent carbon quantum dots.
Size control
Defining the size of silicon quantum dots is essential because it influences their optical properties (especially S-band luminescence). Typically, the size of the silicon quantum dots is defined by controlling material synthesis. For example, silicon quantum dot size can be controlled by the reaction temperature during thermal disproportionation of silsesquioxanes. Similarly, the plasma residence time in non-thermal plasma methods is a key factor. Alternatively, post-synthetic protocols, such as density gradient ultracentrifugation, can be used to narrow the size distribution through separation.
Surface passivation and modification
The synthesis methods used to prepare SiQDs often result in reactive surfaces. Hydride-terminated SiQDs require post synthesis modification because they tend to oxidize under ambient conditions and exhibit limited solution processability. These surfaces are often passivated with organic molecules (e.g., alkyl chains) to render SiQDs resistant to oxidation and compatible with common solvents. This can then be passivated through methods, such as hydrosilylation. Much of the developed surface chemistry draws on well-established procedures used to modify the surface of porous silicon and silicon wafers. Hydrosilylation, which involves the formal addition of a Si-H bond across a C-C double or triple bond, is commonly used to introduce alkenes and alkynes to silicon quantum dot surfaces and also provides access to useful terminal functional groups (e.g., carboxylic acid, ester, silanes) that can define solvent compatibility and provide locations for further derivatization. The covalent bonding between the surface groups and the silicon quantum dot is robust and is not readily exchangeable – this is very different from the ionic bonding commonly used to tether surface groups to other types of quantum dots.
Applications
Silicon quantum dots have been used in prototype applications owing to their biocompatibility and the ubiquitous nature of silicon, compared to other types of quantum dots. In addition to these fundamental properties, the unique optical properties of silicon quantum dots (i.e., long-lived excited states, large Stokes shift and tunable luminescence) can be advantageous for certain applications. Owing to these (and other) properties, the potential applications of SiQDs are diverse, spanning medical, sensing, defense, and energy related fields.
Biological imaging
The biocompatibility of silicon quantum dots along with their long luminescent lifetimes and near-infrared emission makes them well-suited for fluorescence imaging in biological systems. Due to this promise, silicon quantum dots have been applied for both in vitro and in vivo imaging. While steady-state imaging is traditionally used, the keen advantage of silicon comes into play for time-gated imaging. Time-gated imaging employs a delay between the excitation and the luminescence detection, this allows fluorophores with short lifetimes to relax, thus highlighting those with long lifetimes. This type of fluorescence imaging is useful for biological imaging as many tissues exhibit autofluorescence that can interfere with imaging. By using this technique, the signal to background ratio for imaging SiQDs can be increased up to 3x over conventional steady-state imaging techniques.
Other modes of imaging have also been explored for silicon nanomaterials. For example, the silicon core of large silicon nanoparticles has been used for 29Si MRI in mice models. By modifying the surface with a ligand that can coordinate 64Cu, PET imaging is also accessible. Further, doping with paramagnetic centers show promise for T1 and T2 weighted 1H MRI.
Luminescent solar concentrators
Luminescent solar concentrators take advantage of the large Stokes shift of the silicon quantum dots to convert light into electricity. The large Stokes shift allows the SiQDs to convert UV light into red/near infrared light that is effectively absorbed by silicon solar cells, while having limited self absorption. The LSCs are designed to collect light and use the glass to waveguide the re-emitted light towards the edges of the glass, where the solar cells collect the light and convert it to electricity. By designing the LSC carefully, the silicon quantum dots can be prepared as a transparent film over the glass limiting losses due to scattering, while making them suitable as replacements for windows in buildings. To do this effectively, the surface of the silicon quantum dots can be modified with various ligands to improve polymer compatibility. It is also desirable to push the absorbance of the SiQDs into the visible to correspond better with the solar spectrum, which can be accomplished by adding a dye.
Light-emitting diodes
Quantum dot displays utilize quantum dots to produce pure monochromatic light. Most of the work designing LEDs based on silicon quantum dots have focused on electroluminescence of the silicon quantum dots. By changing the size of the SiQDs, the LED emission can be tuned from deep red (680 nm) to orange/yellow (625 nm). Despite promising initial results and advances towards improving the external quantum efficiency of the resulting LEDs, future work is required to overcome the broad luminescence emission.
Sensing
Photochemical sensors take advantage of the silicon quantum dot photoluminescence by quenching photon emission in the presence of the analyte. Photochemical sensors based on silicon quantum dots have been used to sense a wide variety of analytes, including pesticides, antibiotics, nerve agents, heavy metals, ethanol, and pH, often employing either electron transfer or fluorescence resonance energy transfer (FRET) as the method of quenching. Hazardous high energy materials, such as nitroaromatic compounds (i.e., TNT and DNT), can be detected at nanogram levels via electron transfer. In the electron transfer method, the energy level of LUMO of the molecule is between the valence and conduction bands of the silicon quantum dots, enabling the transfer of an excited state electron to the LUMO, and, therefore, preventing radiative recombination of the electron hole pair. This also works when the HOMO of the analyte is just above the conduction band of the SiQD, enabling the electron to transfer from the analyte to the SiQD.
Alternative methods of detection via quenching of the SiQD core have also been explored. By functionalizing the quantum dots with enzymes, various biologically relevant materials can be sensed due to the formation of metabolites. Using this method, glucose can be detected via the formation hydrogen peroxide that quenches luminescence. Another method uses ratiometric sensing, where a fluorescent molecule is used as a control and the relative intensities of the two fluorescent labels are compared. This method was used to detect organophosphate nerve agents visually at a lower concentration than can be observed for SiQD quenching alone.
See also
Cadmium-free quantum dot
References
Semiconductor structures
Quantum electronics
Quantum dots
Optoelectronics
Nanoelectronics
Nanoparticles by composition
Silicon photonics | Silicon quantum dot | [
"Physics",
"Materials_science"
] | 2,675 | [
"Silicon photonics",
"Quantum electronics",
"Quantum mechanics",
"Condensed matter physics",
"Nanoelectronics",
"Nanotechnology"
] |
69,835,830 | https://en.wikipedia.org/wiki/Trojan%20Source | Trojan Source is a software vulnerability that abuses Unicode's bidirectional characters to display source code differently than the actual execution of the source code. The exploit utilizes how writing scripts of different reading directions are displayed and encoded on computers. It was discovered by Nicholas Boucher and Ross Anderson at Cambridge University in late 2021.
Background
Unicode is an encoding standard for representing text, symbols, and glyphs. Unicode is the most dominant encoding on computers, used in over 98% of websites . It supports many languages, and because of this, it must support different methods of writing text. This requires support for both left-to-right languages, such as English and Russian, and right-to-left languages, such as Hebrew and Arabic. Since Unicode aims to enable using more than one writing system, it must be able to mix scripts with different display orders and resolve conflicting orders. As a solution, Unicode contains characters called bidirectional characters (Bidi) that describe how text is displayed and represented. These characters can be abused to change how text is interpreted without changing it visually, as the characters are often invisible.
Methodology
In the exploit, bidirectional characters are abused to visually reorder text in source code so that later execution occurs in a different order.
Bidirectional characters can be inserted in areas of source code where string literals are allowed. This often applies to documentation, variables, or comments.
In the above example, the RLI mark (right-to-left isolate) forces the following text to be interpreted differently than it is displayed: the triple-quote is first (ending the string), followed by a semicolon (starting a new line), and finally with the premature return (returning and ignoring any code below it). The new line terminates the RLI mark, preventing it from flowing into the below code. Because of the Bidi character, some source code editors and IDEs rearrange the code for display without any visual indication that the code has been rearranged, so a human code reviewer would not normally detect them. However, when the code is inserted into a compiler, the compiler may ignore the Bidi character and process the characters in a different order than visually displayed. When the compiler is finished, it could potentially execute code that visually appeared to be non-executable. Formatting marks can be combined multiple times to create complex attacks.
Impact and mitigation
Programming languages that support Unicode strings and follow Unicode's Bidi algorithm are vulnerable to the exploit. This includes languages like Java, Go, C, C++, C#, Python, and JavaScript.
While the attack is not strictly an error, many compilers, interpreters, and websites added warnings or mitigations for the exploit. Both GNU GCC and LLVM received requests to deal with the exploit. Marek Polacek submitted a patch to GCC shortly after the exploit was published that implemented a warning for potentially unsafe directional characters; this functionality was merged for GCC 12 under the -Wbidi-chars flag. LLVM also merged similar patches.
Rust fixed the exploit in 1.56.1, rejecting code that includes the characters by default. The developers of Rust found no vulnerable packages prior to the fix.
Red Hat issued an advisory on their website, labeling the exploit as "moderate". GitHub released a warning on their blog, as well as updating the website to show a dialog box when Bidi characters are detected in a repository's code.
References
External links
https://trojansource.codes/ site by the discoverers, Nicholas Boucher and Ross Anderson
Proof of concept code
Trojan Source full research paper
NIST National Vulnerability Database & CVE Common Vulnerabilities and Exposures
CVE-2021-42574 - NIST & CVE (BIDI exploit)
CVE-2021-42694 - NIST & CVE (homoglyph attack)
UAX 9 from the Unicode Consortium about bidirectional characters and formatting
Unicode UTR 36 from the Unicode Consortium, which describes the vulnerability in Unicode
CERT/CC vulnerability report
2021 in computing
Injection exploits
Software bugs | Trojan Source | [
"Technology"
] | 855 | [
"Computer security exploits",
"Injection exploits"
] |
69,837,182 | https://en.wikipedia.org/wiki/Comparison%20of%20psychoactive%20alcohols%20in%20alcoholic%20drinks | Comparison of psychoactive alcohols in alcoholic beverages.
The Lucas test in alcohols is a test to differentiate between primary, secondary, and tertiary alcohols.
General
Pharmacology
Difference to ethanol
Characteristic
References
Alcohol
Drug-related lists
Comparison of psychoactive substances | Comparison of psychoactive alcohols in alcoholic drinks | [
"Chemistry"
] | 53 | [
"Drug-related lists"
] |
69,840,223 | https://en.wikipedia.org/wiki/CKLF%20like%20MARVEL%20transmembrane%20domain-containing%201 | CKLF like MARVEL transmembrane domain-containing 1 (i.e. CMTM1), formerly termed chemokine-like factor superfamily 1 (i.e. CKLFSF1), has 23 known isoforms, the CMTM1-v1 to CMTM1-v23 proteins. Protein isoforms are variant products that are made by alternative splicing of a single gene. The gene for these isoforms, CMTM1 (formerly termed CKLFSF1), is located in band 22 on the long (i.e. "q") arm of chromosome 16. The CMTM1 gene and its 23 isoforms belong to the CKLF-like MARVEL transmembrane domain-containing family of structurally and functionally related genes and proteins. CMTM1 (isoforms not specified) proteins are weakly express in a wide range of normal tissues but are far more highly expressed in normal testes as well as the malignant cells of certain types of cancer.
Studies have reported that the levels of CMTM1 (typically the CMTM1–v17 isoform) are more highly expressed in breast, kidney, lung, ovary, liver (i.e. hepatocellular carcinoma), and salivary gland adenoid cystic carcinoma malignant tissues than the nearby normal tissues of these respective organs. According to the Human Protein Atlas, higher levels of CMTM1 expression in hepatocellular carcinoma tissues are associated with shorter survival times. Another study found that the levels of CMTM1 mRNA (which directs the production of CMTM1 protein) were higher in stomach cancer compared to nearby normal stomach tissues. And, studies of glioblastoma found no significant difference between the levels of CMTM1 in this brain tumor's tissues versus nearby normal brain tissues but higher levels of tumor tissue CMTM1 were associated with poorer prognoses. In addition, the forced overexpression of CMTM1 in cultured glioblastoma cell lines increased their proliferation and invasiveness. These findings suggest that CMTM1 proteins may act to promote the cited cancers and support further studies to determine if these proteins contribute to the development and/or progression of the cited cancers, can be used as markers of disease severity and/or prognosis, or are targets for treating these cancers.
In contrast to the findings in the cancers just cited, cell culture studies indicated that the forced overexpression of the CMTM1-v5 isoform induced apoptosis (i.e. cell death due to the activation of cell death-inducing signaling pathways) in two types of lymphoma cell lines, Jurkat cells (a human T cell leukemia cell line) and Raji cells (a human non-Hodgkin's lymphoma cell line). Simple addition of CMTM1-v5 protein to cultures of Daudi or Ramos cells (both are Burkitt's lymphoma cell lines) or Jurkat cells likewise caused these cells to become apoptotic. Various other cultured hematological tumor cell lines had no such response to the CMTM1-v5 protein. Finally, the injection of CMTM1-v5 into mice containing Raji cell tumors in a xenotransplantation model of cancer inhibited the spread of these tumors and prolonged the survival of the mice. These findings suggest that CMTM1-v5 protein may act to suppress certain types of lymphoma in humans and support initial studies to define the CMTM1-v5 levels in the malignant cells of humans with these lymphomas. Further studies are also needed to determine the basis for the CMTM1 proteins' promoting actions in the cited cancers versus suppressing actions in the cited lymphomas.
References
Human proteins
Gene expression | CKLF like MARVEL transmembrane domain-containing 1 | [
"Chemistry",
"Biology"
] | 798 | [
"Gene expression",
"Molecular genetics",
"Cellular processes",
"Molecular biology",
"Biochemistry"
] |
69,841,016 | https://en.wikipedia.org/wiki/SN%202020oi | SN 2020oi was a supernova event in the grand design spiral galaxy known as Messier 100, or NGC 4321. It was discovered January 7, 2020 at an apparent magnitude of 17.28 by F. Forster and associates using the Zwicky Transient Facility. The position places it north of the galactic nucleus. The supernova was not detected on an observation made three days before the discovery, and thus it must have begun during that brief period. The light curve peaked around January 13–18, depending on the wavelength, then declined rapidly over a period of 25 days before flattening into a more gradual decline. Observations of the spectrum made with the SOAR telescope showed this to be a type Ic supernova, with the progenitor being a massive star that had its outer envelope stripped. The initial velocity of the expanding photosphere was .
Models of the event give an initial (zero age main sequence) estimated mass of or for the progenitor. It was a member of a binary star system and lost its outer envelope of hydrogen and helium due to interaction with its companion. The resulting helium-poor star was primarily made of carbon and oxygen with a mass of about . The supernova explosion was the result of a collapse of an inert iron core. The event ejected of material and left behind a neutron star remnant with a presumed mass of . The explosion released about of energy, of which 60% was expended on kinetic energy.
This is one of the few type Ic supernovae for which radio emission has been detected. Based on this data, the shock wave from the explosion advanced through the surrounding interstellar matter with a velocity of 3−. In order to produce the observed emission, the progenitor star underwent mass loss at an average rate of ·yr−1 at a typical wind velocity of . Images of the location taken prior to the event using the Hubble Space Telescope show a stellar cluster at that location.
References
Further reading
Supernovae
Messier 100
Coma Berenices
Astronomical objects discovered in 2020 | SN 2020oi | [
"Chemistry",
"Astronomy"
] | 413 | [
"Supernovae",
"Astronomical events",
"Constellations",
"Explosions",
"Coma Berenices"
] |
69,841,132 | https://en.wikipedia.org/wiki/Lavinite | Lavinite () is a mixture of metal particles (usually iron) and sand held together by solidified molten sulfur. Instead of metal particles, magnesite could be used to give a whiter product. The idea was to make a material that looks like marble.
It was invented c. 1912 by Willy Henker, who in that year opened the factory "Kunststein-Industrie W. Henker & Co" in Berlin, which was in operation until at least 1936. Henker produced decorative items from lavinite such as vases, candlesticks, lamps, chandeliers and rosettes as well as letters and advertising signs.
Lavinite products were usually black, less often white or colored, enameled or covered with "antique" bronze. Initially, the factory offered items in the Art Nouveau style. Later they introduced lines in antique, oriental and Art Deco styles.
In 1922, Kunststein-Industrie W. Henker & Co opened a sales office in New York City and lavinite became very popular in the United States. Afterwards, Henker sold the patent for lavinite production to the U.S., France, Austria and Poland. In 1923 the factory "Lavinit. Krupka I Perlicz" opened in Włocławek, Poland, where it operated until 1939. They offered products from Willy Henker's factory catalogue. Over time, the assortment was expanded by items referring to the history of Poland, such as busts of Prince Józef Poniatowski or Adam Mickiewicz. For a short time, lavinite items were also produced by the Wulkanit factory in Grudziądz.
Currently, decorative items in lavinite are popular and valued at auctions all around the world. The biggest collection of them, comprising 63 items, is in the Muzeum Ziemi Kujawskiej i Dobrzyńskiej in Włocławek.
References
Alloys
Decorative arts
Polish brands | Lavinite | [
"Chemistry"
] | 410 | [
"Alloys",
"Chemical mixtures"
] |
69,841,961 | https://en.wikipedia.org/wiki/Germaine%20Benoit | Germaine Benoit (9 October 1901 – April 1983) was a French chemical engineer, pharmacologist and biologist, best known for her contributions to the study of sympathomimetic drugs.
Early life
Benoit was born on 9 October 1901 in Paris. She was an only child, and lost her father, a German teacher, in her teens, as he disappeared during the First World War.
Education
In 1918 and 1919, she earned two baccalaureates and the following year, gained her certificate in physics, chemistry and natural sciences (PCN), in preparation for medical studies. She then enrolled at the Institut de chimie appliquée, the future École nationale supérieure de chimie, where she studied for three years. She graduated in chemical engineering in 1923. Between 1922 and 1936 she earned five scientific degrees, in chemistry and biology.
Career
On 1 June 1924, Benoit joined the Pasteur Institute as an assistant in the medicinal chemistry laboratory directed by Ernest Fourneau. Ten years later, in 1934, she received the Prix Louis from the Académie de Médecine for her research on sympathomimetic drugs. During that time, she was part of the first major advances in the fight against sleeping sickness and malaria through her significant chemical engineering contributions to the discovery and development of drugs such as orsanine and rhodoquine.
In 1942, Benoit defended her doctoral thesis on hydrazine compounds. She continued to work in the medical chemistry department, and was appointed head of the laboratory in 1943. In 1947, she was made a Knight of the Légion d'honneur.
In 1960, Benoit was recruited by Daniel Bovet to work at the Istituto Superiore di Sanità in Rome.
Personal life
The following year, she married Albert Funke, who was also head of the laboratory of therapeutic chemistry at the Pasteur Institute, with whom she had collaborated for many years. The couple were friends with Jacques Monod. She and her husband retired in 1962 on their return from working in Italy.
Germaine Benoit died in Paris in April 1983.
Publications
1927: Sur les isomères de l'acide para-oxy-3-amino-phényl-arsinique et de son dérivé acétylé (stovarsol) Bulletin de la Société chimique de France. 4 (in French). 41: 499–514. 1927. ScF-41-1927 with Ernest Fourneau and Jacques and Thérèse Tréfouël.
1930: Contribution à l'étude des anesthésiques locaux: Dérivés des amino-alcools à fonction alcoolique primaire Bull. Soc. chim. Fr., 4e série, vol.47, 1930, S. 858–885, with E. Fourneau and Roger Firmenich.
1930: Synthèse d'un isomère et d'un homologue de l'éphédrine Bull. Soc. chim. 4e série, vol.47, 1930, S. 894–980, with E. Fourneau and R. Firmenich.
1930: Contribution à la chimiothérapie du paludisme: Essais sur la malaria des canaris, Annales de l'Institut Pasteur, vol.44, no5, mai 1930, S. 503–533 (Zusammenfassung), with E. Fourneau, J. and Th. Tréfouël, Georges Stefanopoulo, Yvonne de Lestrange and Kenneth L. Melville.
1930: Préparation de dérivés en vue d'essais thérapeutiques. I. Amino-alcools. II. Dérivés de l'atophan. III. Dérivés du carbostyryle. IV. Dérivés quinoléiniques et quinoléine arsinique, Ann. Inst. Pasteur, vol.44, no6, Juni 1930, S. 719–751, with E. Fourneau and J. and Th. Tréfouël.
1931: Contribution à la chimiothérapie du paludisme: Essais sur les calfats, Ann. Inst. Pasteur, vol.46, 1931, S. 514–541, with E. Fourneau, J. and Th. Tréfouël and Daniel Bovet.
1933: Contribution à la chimiothérapie du paludisme: Essais sur les calfats (deuxième mémoire), Ann. Inst. Pasteur, vol.50, 1933, S. 731–744, with E. Fourneau, J. and Th. Tréfouël and D. Bovet.
1934: Action thérapeutique de quinoléines à poids moléculaire élevé, homologues de la plasmoquine, sur les hématozoaires des calfats et des serins, Bulletins de la Société de pathologie exotique et de ses filiales de l'Ouest africain et de Madagascar, vol.27, Nr. 3, 1934, S. 236–242, with D. Bovet and Reinout Altman.
1935: Étude chimique et physiologique d'amines à fonction éthylénique et de diamines, Bulletin des sciences pharmacologiques, vol.42, Nr. 1 und 2, Januar und Februar 1935, S. 34–43 und 102–109, with Rudolf Herzog.
1938: Synthèse et étude pharmacologique de quelques dérivés hétérocycliques voisins de l'amino-méthylbenzodioxane, Bull. sc. pharmacol., vol.45, Nr. 3, März 1938, S. 97–107, mit D. Bovet.
1942: Préparation et propriétés physiologiques de quelques hydroxy-alcoyl-hydrazines... Thèses présentées à la Faculté des sciences de l'Université de Paris pour obtenir le grade de docteur ès sciences physiques par Germaine Benoit.
1945: Sur l'acide corynanthique, Bull. Soc. chim. Fr., 5e série, vol.12, 1945, S. 934–936, with E. Fourneau.
1945: Éphédrine et isoéphédrines, Bull. Soc. chim. Fr., 5e série, vol.12, 1945, S. 985–989, with E. Fourneau.
1947: Hydroxy-alcoyl-hydrazines. 2., Bull. Soc. chim. Fr., 5e série, vol.14, Nr. 3–4, 1947, S. 242–244.
1950: Synthèse et propriétés thérapeutiques des dérivés aminés et hydroxylés du stilbène, Bull. Soc. chim. Fr., 5e série, vol.17, Nr. 9–10, 1950, S. 829–832, mit Dimitri Marinopoulos.
1951: Synthèse de quelques dérivés aminés du diphénylméthane, Bull. Soc. chim. Fr., 5e série, vol.18, 1951, S. 890–895, mit Fanny Eliopoulo.
1951 : , with Joseph Jacob et F. Eliopoulo.
1952 : , avec Roger Delavigne et F. Eliopoulo.
1953 : , with R. Delavigne.
1953 : , with Albert Funke.
1955: Ammoniums quaternaires dans la série des acides hydroxamiques. I: Synthèse d'iodométhylates d'acides diméthylaminobenzoylhydroxamiques, antagonistes du diisopropyfluorophosphate, C. r. hebd. séances Acad. sci., vol.240, Nr. 26, 27. Juni 1955, S. 2575–2577, with A. Funke and J. Jacob.
1955: Synthèse et propriétés pharmacologiques de quelques ω-phényl-ω-carbétoxy-alcoyl-1-méthyl-4-pipérazines, C. r. hebd. séances Acad. sci., vol.241, Nr. 6, September 1955, S. 581–583, with Bal Krishna Avasthi, J. Jacob and Monique Dechavassine.
1955: Action de l'éthylénénimine sur les époxydes. 2., Bull. Soc. chim. Fr., 5e série, vol.22, Nr. 7–8, 1955, S. 946–947, with Albert Funke.
1958: Synthèse d'acides diméthylaminobenzoylhydroxamiques et de leurs dérivés, Bull. Soc. chim. Fr., 5e série, vol.25, Nr. 2, 1958, S. 257–258, with A. Funke.
1958: Sur quelques dérivés N,N-disubstitués de la pipérazine, Bull. Soc. chim. Fr., vol.25, Nr. 11–12, 1958, S. 1358–1364, with Bal Krishna Avasthi.
1959: Contribution à l'étude des propriétés chimiques de la R-bêta-cyclohexyltétraline-I, Bull. Soc. chim. Fr., vol.26, Nr. 7–8, 1959, S. 1197–1199, with R. Delavigne.
1960: Benzodioxoles-1,3 substitués, Bull. Soc. chim. Fr., 5e série, vol.27, Nr. 4, 1960, S. 638–642, mit B. Millet.
1961: Dérivés de la phényl-2 dihydro-2,3 benzothiazine-1,4, Bull. Soc. chim. Fr., 5e série, vol.28, Nr. 8–9, 1961, S. 1524 ff., mit A. Funke und B. Millet.
Image
Portrait photograph of Germaine Benoit by Henri Manuel (c. 1925).
References
1901 births
1983 deaths
Knights of the Legion of Honour
French pharmacologists
French biochemists
Women chemical engineers
French chemical engineers
People from Paris | Germaine Benoit | [
"Chemistry"
] | 2,229 | [
"Women chemical engineers",
"Chemical engineers"
] |
69,842,575 | https://en.wikipedia.org/wiki/Ascobolus%20brantophilus | Ascobolus brantophilus is a species of coprophilous fungus in the family Ascobolaceae. It grows on goose droppings.
Ascobolus brantophilus mainly has an Arctic and Subarctic distribution. It described in 1989 from Greenland, Ellesmere Island and Svalbard and has since then been reported from Iceland, the Shetland Islands and the Falkland Islands
References
Pezizales
Fungi described in 1989
Fungi of Iceland
Taxa named by Henry Dissing
Fungus species | Ascobolus brantophilus | [
"Biology"
] | 103 | [
"Fungi",
"Fungus species"
] |
69,842,664 | https://en.wikipedia.org/wiki/Madhusudan%20Katti | Madhusudan Katti is an Indian American environmental scientist who is an Associate Professor of Ecology at the North Carolina State University. His research studies the evolutionary ecology of vertebrate response to human modifications of habitats.
Early life and education
Katti was born in India. He attended The Institute of Science, Mumbai, where he graduated with a bachelor's degree in zoology in 1987. During his undergraduate degree, he became interested in wildlife and birdsong. He joined the Wildlife Institute of India as a graduate student, where he studied wildlife sciences. He moved to the United States for graduate studies and majored in biology. His doctoral research considered the ecology and evolution of leaf warblers in the Great Himalayas. After earning his doctorate, he was made a reconciliation ecologist.
Research and career
In 2016, Katti joined North Carolina State University as the Chancellor's Faculty Excellence Program hire in Leadership in Public Science. His research considers animals and plants in urban environments, with a focus on improving biodiversity amongst human inhabited communities. He has also studied how humans impact animal behavior, for example, how urban noise impacts birdsong. Katti leads the Urban Long-Term research Area – Fresno And Clovis Ecosocial Study (ULTRA-FACES) project, which evaluates how human water use, water policy and urban biodiversity impact one another in the Central Valley in California.
Katti has explored ways to decolonize ecological research. He proposed that efforts to decolonize ecology would involve individual reflection, considering the varied ways of knowing and communicating science, understanding histories, decolonizing access to and expertise in science and practising ecology in ethical inclusive teams.
In 2022, Katti was announced as the executive editor of the Bulletin of the Ecological Society of America.
Selected publications
]
References
Living people
North Carolina State University faculty
Year of birth missing (living people)
Academic journal editors
Environmental scientists
University of California, San Diego alumni
Indian emigrants to the United States
21st-century American scientists
20th-century American scientists | Madhusudan Katti | [
"Environmental_science"
] | 404 | [
"American environmental scientists",
"Environmental scientists"
] |
69,842,816 | https://en.wikipedia.org/wiki/Didymella%20proximella | Didymella proximella is a species of fungus belonging to the family Didymellaceae. It is known to decompose the dead leaves of Carex capillaris.
References
Fungi described in 1882
Pleosporales
Fungus species | Didymella proximella | [
"Biology"
] | 52 | [
"Fungi",
"Fungus species"
] |
69,844,095 | https://en.wikipedia.org/wiki/Redundant%20elevators | Redundant elevators are additional elevators installed to guarantee greater accessibility of buildings and public transportation systems in the event that an elevator malfunctions or is undergoing repairs. The United States Disability Rights Education and Defense Fund describes redundant elevators as a "best practice" and recommends all transit agencies "consider installing redundant elevators at all existing key stations with elevators in rapid, light, and commuter rail, and at all Amtrak stations with elevators."
Legislation
United States
The Americans with Disabilities Act of 1990 requires elevators for new construction and alterations in public accommodations and commercial facilities, with some exceptions. However, there are no requirements for redundant elevators.
Redundant elevators in public transportation
Canada
Ottawa
Ottawa's OC Transpo has committed to installing redundant elevators at all transfer stations and stations where alternative accessible routes cannot be provided.
United States
Bay Area Rapid Transit
All Bay Area Rapid Transit stations have accessible elevators, however most stations lack redundant elevators. BART has committed to increasing elevator redundancy within its system.
Connecticut Department of Transportation
Connecticut Department of Transportation policy states that at stations without redundant elevators, signage must be posted near all elevators displaying a 24-hour monitored telephone number that connects the passenger to a mobility taxi service.
MBTA
As part of a 2006 agreement between the Massachusetts Bay Transportation Authority (MBTA) and the Boston Center for Independent Living, MBTA has agreed to install redundant elevators at stations in their system.
Metropolitan Transportation Authority
Washington Metro
Since 2003, the Washington Metro has required that all newly constructed stations must have redundant elevators. As of 2021, all Washington Metro stations are wheelchair accessible but the majority of stations lack redundant elevators. 15 out of 91 stations have at least one redundant elevator, with redundant elevators planned for installation at four other stations.
References
Accessibility
Disability rights
Elevators | Redundant elevators | [
"Engineering"
] | 347 | [
"Building engineering",
"Accessibility",
"Design",
"Elevators"
] |
69,845,004 | https://en.wikipedia.org/wiki/Conical%20refraction | Conical refraction is an optical phenomenon in which a ray of light, passing through a biaxial crystal along certain directions, is refracted into a hollow cone of light. There are two possible conical refractions, one internal and one external. For internal refraction, there are 4 directions, and for external refraction, there are 4 other directions.
For internal conical refraction, a planar wave of light enters an aperture a slab of biaxial crystal whose face is parallel to the plane of light. Inside the slab, the light splits into a hollow cone of light rays. Upon exiting the slab, the hollow cone turns into a hollow cylinder.
For external conical refraction, light is focused at a single point aperture on the slab of biaxial crystal, and exits the slab at the other side at an exit point aperture. Upon exiting, the light splits into a hollow cone.
This effect was predicted in 1832 by William Rowan Hamilton and subsequently observed by Humphrey Lloyd in the next year. It was possibly the first example of a phenomenon predicted by mathematical reasoning and later confirmed by experiment.
History
The phenomenon of double refraction was discovered in the Iceland spar (calcite), by Erasmus Bartholin in 1669. was initially explained by Christiaan Huygens using a wave theory of light. The explanation was a centerpiece of his Treatise on Light (1690). However, his theory was limited to uniaxial crystals, and could not account for the behavior of biaxial crystals. inside the sphere.
In 1813, David Brewster discovered that topaz has two axes of no double refraction, and subsequently others, such as aragonite, borax and mica, were identified as biaxial. Explaining this was beyond Huygens' theory.
At the same period, Augustin-Jean Fresnel developed a more comprehensive theory that could describe double refraction in both uniaxial and biaxial crystals. Fresnel had already derived the equation for the wavevector surface in 1823, and André-Marie Ampère rederived it in 1828. Many others investigated the wavevector surface of the biaxial crystal, but they all missed its physical implications. In particular, Fresnel mistakenly thought the two sheets of the wavevector surface are tangent at the singular points (by a mistaken analogy with the case of uniaxial crystals), rather than conoidal.
William Rowan Hamilton, in his work on Hamiltonian optics, discovered the wavevector surface has four conoidal points and four tangent conics. These conoidal points and tangent conics imply that, under certain conditions, a ray of light could be refracted into a cone of light within the crystal. He termed this phenomenon "conical refraction" and predicted two distinct types: internal and external conical refraction, corresponding respectively to the conoidal points and tangent conics.
Hamilton announced his discovery at the Royal Irish Academy on October 22, 1832. He then asked Humphrey Lloyd to prove this experimentally. Lloyd observed external conical refraction 14 December with a specimen of arragonite from the Dollonds, which he published in February. He then observed internal conical refraction and published in March. Lloyd then combined both reports, and added details, into one paper.
Lloyd discovered experimentally that the refracted rays are polarized, with polarization angle half that of the turning angle (see below), told Hamilton about it, who then explained theoretically.
At the same time, Hamilton also exchanged letters with George Biddell Airy. Airy had independently discovered that the two sheets touch at conoidal points (rather than tangent), but he was skeptical that this would have experimental consequences. He was only convinced after Lloyd's report.
This discovery was a significant victory for the wave theory of light and solidified Fresnel's theory of double refraction. Lloyd's experimental data are described in pages 350–355. The rays of the internal cone emerged, as they ought, in a cylinder from the second face of the crystal; and the size of this nearly circular cylinder, though small, was decidedly perceptible, so that with solar light it threw on silver paper a little luminous ring, which seemed to remain the same at different distances of the paper from the arragonite. In 1833, James MacCullagh claimed that it is a special case of a theorem he published in 1830 that he did not explicate, since it was not relevant to that particular paper. Cauchy discovered the same surface in the context of classical mechanics.Somebody having remarked, "I know of no person who has not seen conical refraction that really believed in it. I have myself converted a score of mathematicians by showing them the cone of light". Hamilton replied, "How different from me! If I had seen it only, I should not have believed it. My eyes have too often deceived me. I believe it, because I have proved it."
Geometric theory
A note on terminology: The surface of wavevectors is also called the wave surface, the surface of normal slowness, the surface of wave slowness, etc. The index ellipsoid was called the surface of elasticity, as according to Fresnel, light waves are transverse waves in, in exact analogy with transverse elastic waves in a material.
Surface of wavevectors
For notational cleanness, define . This surface is also known as Fresnel wave surface.
Given a biaxial crystal with the three principal refractive indices . For each possible direction of planar waves propagating in the crystal, it has a certain group velocity . The refractive index along that direction is defined as .
Define, now, the surface of wavevectors as the following set of pointsIn general, there are two group velocities along each wavevector direction. To find them, draw the plane perpendicular to . The indices are the major and minor axes of the ellipse of intersection between the plane and the index ellipsoid. At precisely 4 directions, the intersection is a circle (those are the axes where double refraction disappears, as discovered by Brewster, thus earning them the name of "biaxial"), and the two sheets of the surface of wavevectors collide at a conoidal point.
To be more precise, the surface of wavevectors satisfy the following degree-4 equation (, page 346):or equivalently,
The major and minor axes are the solutions to the constraint optimization problem: where is the matrix with diagonal entries .
Since there are 3 variables and 2 constraints, we can use the Karush–Kuhn–Tucker conditions. That is, the three gradients are linearly dependent.
Let , then we havePlugging back to , we obtain Let be the vector with the direction of , and the length of . We thus find that the equation of is Multiply out the denominators, then multiply by , we obtain the result.
In general, along a fixed direction , there are two possible wavevectors: The slow wave and the fast wave , where is the major semiaxis, and is the minor.
Plugging into the equation of , we obtain a quadratic equation in :which has two solutions . At exactly four directions, the two wavevectors coincide, because the plane perpendicular to intersects the index ellipsoid at a circle. These directions are where , at which point .
Expanding the equation of the surface in a neighborhood of , we obtain the local geometry of the surface, which is a cone subtended by a circle.
Further, there exists 4 planes, each of which is tangent to the surface at an entire circle (a trope conic, as defined later). These planes have equation (, pages 349–350)or equivalently, .
and the 4 circles are the intersection of those planes with the ellipsoidAll 4 circles have radius .
By differentiating its equation, we find that the points on the surface of wavevectors, where the tangent plane is parallel to the -axis, satisfies That is, it is the union of the -plane, and an ellipsoid.
Thus, such points on the surface of wavevectors has two parts: Every point with , and every point that intersects with the auxiliary ellipsoid
Using the equation of the auxiliary ellipsoid to eliminate from the equation of the wavevector surface, we obtain another degree-4 equation, which splits into the product of 4 planes:
Thus, we obtain 4 ellipses: the 4 planar intersections with the auxiliary ellipsoid. These ellipses all exist on the wavevector surface, and the wavevector surface has tangent plane parallel to the axis at those points. By direct computation, these ellipses are circles.
It remains to verify that the tangent plane is also parallel to the plane of the circle.
Let be one of those 4 planes, and let be one point on the circle in . If , then since the circle is on the surface, the tangent plane to the surface at must contain the tangent line to the circle at . Also, the plane must also contain , the line pass that is parallel to the -axis. Therefore, the plane is spanned by and , which is precisely the plane . This then extends by continuity to the case of .
One can imagine the surface as a prune, with 4 little pits or dimples. Putting the prune on a flat desk, the prune would touch the desk at a circle that covers up a dimple.
In summary, the surface of wavevectors has singular points at where . The special tangent plane to the surface touches it at two points that make an angle of and , respectively.
The angle of the wave cone, that is, the angle of the cone of internal conical refraction, is . Note that the cone is an oblique cone. Its apex is perpendicular to its base at a point on the circle (instead of the center of the circle).
Surface of ray vectors
The surface of ray vectors is the polar dual surface of the surface of wavevectors. Its equation is obtained by replacing with in the equation for the surface of wavevectors. That is,All the results above apply with the same modification. The two surfaces are related by their duality:
The four special planes tangent to the surface of wavevectors on a circle correspond to the 4 conoidal points on the surface of ray vectors.
The four conoidal points on the surface of wavevectors correspond to the 4 planes tangent to the surface of ray vectors on a circle.
Approximately circular
In typical crystals, the difference between is small. In this case, the conoidal point is approximately at the center of the tangent circle surrounding it, and thus, the cone of light (in both the internal and the external refraction cases) is approximately a circular cone.
Polarization
In the case of external conical refraction, we have one ray splitting into a cone of planar waves, each corresponding to a point on the tangent circle of the wavevector surface. There is one tangent circle for each of the four quadrants. Take the one with , then take a point on it. Let the point be .
To find the polarization direction of the planar wave in direction , take the intersection of the index ellipsoid and the plane perpendicular to . The polarization direction is the direction of the major axis of the ellipse intersection between the plane perpendicular to and the index ellipsoid.
Thus, the with the highest corresponds to a light polarized parallel to the direction, and the with the lowest corresponds to a light polarized in a direction perpendicular to it. In general, rotating along the circle of light by an angle of would rotate the polarization direction by approximately .
This means that turning around the cone an entire round would turn the polarization angle by only half a round. This is an early example of the geometric phase. This geometric phase of is observable in the difference of the angular momentum of the beam, before and after conical refraction.
Algebraic geometry
The surface of wavevectors is defined by a degree-4 algebraic equation, and thus was studied for its own sake in classical algebraic geometry.
Arthur Cayley studied the surface in 1849. He described it as a degenerate case of tetrahedroid quartic surfaces. These surfaces are defined as those that are intersected by four planes, forming a tetrahedron. Each plane intersects the surface at two conics. For the wavevector surface, the tetrahedron degenerates into a flat square. The three vertices of the tetrahedron are conjugate to the two conics within the face they define. The two conics intersect at 4 points, giving 16 singular points.
In general, the surface of wavevectors is a Kummer surface, and all properties of it apply. For example:
It is projectively isomorphic to its dual surface.
There are at most 16 singular points.
Each trope of the surface corresponds to a singular point on its dual. Here, a trope is defined as a double-conic on the surface. In other words, it is where the intersection of the surface with a plane factors into a perfect square.
For each Kummer surface, there exists a two-dimensional family of lines, such that each point of the surface is tangent to two lines in the family.
More properties of the surface of wavevectors are in Chapter 10 of the classical reference on Kummer surfaces.
Every linear material has a quartic dispersion equation, so its wavevector surface is a Kummer surface, which can have at most 16 singular points. That such a material might exist was proposed in 1910, and in 2016, scientists made such a (meta)material, and confirmed it has 16 directions for conical refraction.
Diffraction theory
The classical theory of conical refraction was essentially in the style of geometric optics, and ignores the wave nature of light. Wave theory is needed to explain certain observable phenomena, such as Poggendorff rings, secondary rings, the central spot and its associated rings. In this context, conical refraction is usually named "conical diffraction" to emphasize the wave nature of light.
Observations
The angle of the cone depends on the properties of the crystal, specifically the differences between its principal refractive indices. The effect is typically small, requiring careful experimental setup to observe. Early experiments used sunlight and pinholes to create narrow beams of light, while modern experiments often employ lasers and high-resolution detectors.
Poggendorff observed two rings separated by a thin dark band. This was explained by Voigt. See Born and Wolf, section 15.3, for a derivation.
Potter observed in 1841 certain diffraction phenomena that were inexplicable with Hamilton's theory. Specifically, if we follow the two rings created by the internal conic refraction, then the inner ring would contract until it becomes a single point, while the outer ring expands indefinitely. A satisfactory explanation required later developments in diffraction theory.
Modern developments
The study of conical refraction has continued since its discovery, with researchers exploring its various aspects and implications. Some recent work includes:
Paraxial theory: This theory provides a simplified description of conical diffraction for small angles of incidence and has been used to analyze the detailed structure of the light patterns observed.
Chiral crystals: The inclusion of optical activity (chirality) in the crystal leads to new phenomena, such as the transformation of the conical cylinder into a "spun cusp" caustic.
Absorption and dichroism: The presence of absorption in the crystal significantly alters the behavior of light, leading to the splitting of diabolical points into pairs of branch points and affecting the emergent light patterns.
Nonlinear optics: Nonlinear optical effects in biaxial crystals can interact with conical refraction, leading to complex and intriguing phenomena.
Applications: Conical refraction had found applications in optical trapping, free-space optical communications, polarization metrology, super-resolution imaging, two-photon polymerization, and lasers.
Conical refraction was also observed in transverse sound waves in quartz.
See also
Birefringence
Wave surface
Crystal optics
Polarization
Caustics
External links
Images of conical refractions with rings of radius larger than one meter, through monocrystal of rhombic sulfur. By Yu. P. Mikhailichenko
Images of the Fresnel wave surface, (pages 470–485 ).
References
Polarization (waves)
Optical mineralogy
Refraction
Optical quantities | Conical refraction | [
"Physics",
"Mathematics"
] | 3,418 | [
"Physical phenomena",
"Physical quantities",
"Refraction",
"Quantity",
"Astrophysics",
"Optical phenomena",
"Optical quantities",
"Polarization (waves)"
] |
69,846,785 | https://en.wikipedia.org/wiki/JCAMP-DX | JCAMP-DX are text-based file formats created by JCAMP for storing spectroscopic data. It started as a file format for Infrared spectroscopy. It was later expanded to cover Nuclear magnetic resonance spectroscopy, mass spectrometry, electron magnetic resonance and circular dichroism spectroscopy. Later extensions for good laboratory practice were added to cover contract laboratories needs. Despite all efforts to create an easy to comprehend standards, most vendor implementations differ slightly. An open source implementation exists in Java.
References
External links
official website
Chemical file formats
Spectroscopy | JCAMP-DX | [
"Physics",
"Chemistry"
] | 110 | [
"Mass spectrometry data formats",
"Spectrum (physical sciences)",
"Molecular physics",
"Chemistry software",
"Instrumental analysis",
"Mass spectrometry",
"Spectroscopy",
"Chemical file formats"
] |
69,847,260 | https://en.wikipedia.org/wiki/Lophodermium%20caricinum | Lophodermium caricinum is a species of fungus in the family Rhytismataceae. It is a decomposer known to live on dead tissues of Carex capillaris, Carex machlowiana, Eriophorum angustifolium and Kobresia myosuroides.
References
Fungi described in 1861
Leotiomycetes
Fungus species | Lophodermium caricinum | [
"Biology"
] | 78 | [
"Fungi",
"Fungus species"
] |
74,398,303 | https://en.wikipedia.org/wiki/Periscope%20lens | A periscope lens, sometimes called a folded lens, is a mechanical assembly of lens elements that uses a prism or mirror to redirect the light through the lenses with a 90° angle to the optical axis, as in a periscope.
Uses
The Kenworthy/Netman Snorkel Camera System, introduced in 1967 by Norman Paul Kenworthy and Bob Nettman, uses periscope lenses to allow filming very small scale models and objects from a very close distance.
Smartphones use periscope lenses to allow larger zoom ratios without increasing (too much) their thickness. The increased optical zoom range is aimed to improve macro photography. With a periscope lens, the zoom lenses are turned by 90° and are aligned along the length or the width of the smartphone instead of its depth. The Sharp 902, released in 2004, is sometimes credited to be the first mobile phone to feature a (2x variable zoom) periscope lens camera. The Asus ZenFone Zoom smartphone, released in 2015, used an Hoya dual-periscope lens mechanism to achieve a 3x zoom. In 2019, the Huawei P30 Pro featured a 5x zoom periscope lens. In 2020, the Huawei P40 Pro+ introduced a 10x zoom periscope lens camera.
See also
List of longest smartphone telephoto lenses
References
Telescopes
Film and video terminology
See also
Folded optics
List of longest smartphone telephoto lenses | Periscope lens | [
"Astronomy"
] | 298 | [
"Telescopes",
"Astronomical instruments"
] |
74,398,760 | https://en.wikipedia.org/wiki/HD%2027322 | HD 27322, also known as HR 1342, is a binary star located in the northern circumpolar constellation Camelopardalis. The visible component is faintly visible to the naked eye as a white-hued point of light with an apparent magnitude of 5.92. The object is located relatively close at a distance of 313 light-years based on Gaia DR3 parallax measurements, and it is drifting closer with a heliocentric radial velocity of approximately . At its current distance, HD 27322's brightness is diminished by 0.24 magnitudes due to interstellar extinction and it has an absolute magnitude of +0.98.
HD 27322 A has a stellar classification of A3 V, indicating that it is an ordinary A-type main-sequence star that is generating energy via hydrogen fusion at its core. Abt & Morell (1995) gave a hotter and slightly more evolved classification of A2 IV-V, indicating that it is an A-type star with a luminosity class intermediate between a main sequence star and a subgiant. At the age of 640 million years, HD 27322 A has completed 79.5% of its main sequence lifetime. It has 1.9 times the mass of the Sun and 2.64 times the radius of the Sun. It radiates 54.7 times the luminosity of the Sun from its photosphere at an effective temperature of . HD 27322 A is metal deficient with an iron abundance 56% that of the Sun's ([Fe/H] = −0.25) and it spins rapidly with a projected rotational velocity of .
The object was generally classified as a solitary star. However, evidence of HD 27322 being a binary first arose when an X-ray emission with a luminosity of was detected around the star. A-type stars are expected to be X-ray quiet, so it might be coming from a hidden companion. A 2016 spectroscopic survey detected a companion around HD 27322. It has 1.3 times the mass of the Sun and it has an effective temperature of 6,492 K. HD 27322 B is metal deficient with a [Fe/H] of −0.5 and it spins modestly with a projected rotational velocity of 20 km/s.
References
Camelopardalis
027322
020380
1342
A-type main-sequence stars
BD+56 00509
Binary stars | HD 27322 | [
"Astronomy"
] | 504 | [
"Camelopardalis",
"Constellations"
] |
74,399,925 | https://en.wikipedia.org/wiki/Alexandra%20Gade | Alexandra Gade (born 1974) is a nuclear physicist who studies the nuclear structure of heavy elements, exotic nuclei, and rare isotopes, using techniques including nuclear spectroscopy, nucleon knockouts, and Coulomb excitation. Educated in Germany, she works at Michigan State University in the US as a professor of physics in the department of physics and astronomy and as deputy scientific director of the facility for rare isotope beams.
Education and career
Gade studied experimental nuclear physics at the University of Cologne, working there with Peter von Brentano. She earned a diploma in 1998, and completed her doctorate (Dr. rer. nat.) in 2002.
After postdoctoral research at the National Superconducting Cyclotron Laboratory (NCSL) at Michigan State University, she continued at the NCSL as an assistant professor beginning in 2004, and added an affiliation as an assistant professor of physics at Michigan State in 2006. She was promoted to associate professor in 2009 and full professor in 2013.
From 2015 to 2022 she was chief scientist for the NCSL. She has been deputy scientific director of the Facility for Rare Isotope Beams since 2020.
Recognition
Gade was named a Fellow of the American Physical Society (APS) in 2013, after a nomination from the APS Division of Nuclear Physics, "for her work in developing sensitive techniques based on gamma-ray detection to explore the properties of rare isotopes". In 2020 she was named as a Fellow of the American Association for the Advancement of Science, "for distinguished contributions to the field of nuclear physics, particularly for gamma-ray spectroscopy of rare isotopes and elucidating the structural properties of nuclei".
She was the 2015 recipient of the Zdzisław Szymański Prize of the University of Warsaw, given "in recognition of her leadership in the exploration of the structure of exotic nuclei at the extremes of neutron to proton ratio and, in particular, for her seminal studies of spectroscopic factors in nuclei far from the valley of nuclear stability". The Diploma was awarded on September 12th during the XXXIV Mazurian Lakes Conference of Physics held in September 6–13, 2015 at Piaski, Poland.
References
External links
Home page
1974 births
Living people
German physicists
German women physicists
American physicists
American women physicists
Nuclear physicists
University of Cologne alumni
Michigan State University faculty
Fellows of the American Physical Society | Alexandra Gade | [
"Physics"
] | 482 | [
"Nuclear physicists",
"Nuclear physics"
] |
74,400,875 | https://en.wikipedia.org/wiki/Kriegeria | Kriegeria is a genus of fungi in the subdivision Pucciniomycotina. The genus is currently monotypic, containing the single species Kriegeria eriophori. The species is a plant pathogen, parasitic on sedges, and produces auricularioid (laterally septate) basidia and basidiospores that germinate to form a yeast state.
Taxonomy
Both the genus and the species were described in 1891 by Italian mycologist Giacomo Bresadola, based on a specimen collected in Saxony by German mycologist Karl Wilhelm Krieger. Rabenhorst had proposed the name Kriegeria previously for an ascomycetous fungus, leading to the creation of the replacement genus Xenogloea for Bresadola's species. Rabenhorst's Kriegeria was, however, invalidly published and Bresadola's Kriegeria is the legitimate name, with the later Xenogloea as an illegitimate synonym. The anamorphic yeast state was given the name Zymoxenogloea eriophori, but, following changes to the International Code of Nomenclature for algae, fungi, and plants, the practice of giving different names to teleomorph and anamorph forms of the same fungus was discontinued, meaning that Zymoxenogloea became a synonym of the earlier name Kriegeria.
Molecular research, based on cladistic analysis of DNA sequences, has shown that Kriegeria is a monophyletic (natural) genus.
Description
The fungus grows within the host leaves, producing hyphae with clamp connections. Basidia emerge through the leaf's stoma in a gelatinous matrix and are auricularioid (tubular and laterally septate), forming a weakly pustular, yellowish basidiocarp on the undersurface of the leaf. The basidiospores are smooth, hyaline, and fusoid-cylindrical, measuring 18-30 x 7-11 μm. They germinate by budding off yeast cells.
Habitat and distribution
The species was originally found on Eriophorum angustifolium (cottongrass) in Europe, but has also been found on Scirpus sylvaticus (wood clubrush) and, in North America, Scirpus atrovirens (dark-green bulrush). In Europe, Kriegeria eriophori has been recorded from Germany and the Czech Republic; in North America, from Canada and the USA. It appears to be rare or rarely recorded.
References
Basidiomycota genera
Pucciniomycotina
Yeasts
Taxa described in 1891
Taxa named by Giacomo Bresadola | Kriegeria | [
"Biology"
] | 574 | [
"Yeasts",
"Fungi"
] |
74,402,704 | https://en.wikipedia.org/wiki/ADI%20Design%20Museum | The ADI Design Museum is a museum in Milan, Italy, which houses the historical collection of the ADI Compasso d'Oro Foundation, as well as temporary exhibitions, public talks and initiatives. It is dedicated to the understanding and promotion of design in Italy and abroad.
History
The ADI Design Museum was established in 2001 in order to exhibit, promote, and conserve the collection of Compasso d'Oro winning designs and related archival material held by the Associazione per il Disegno Industriale (ADI) in Milan, Italy. The collection includes over 350 objects and works dating back to the inception of the Compasso d'Oro Award in 1954.
The museum has been located in a converted industrial building on Piazza Compasso d'Oro in the Porta Volta neighbourhood of Milan since 2021. It was designed by the architects Mara Servetto, Ico Migliore (Migliore + Servetto), with the designer Italo Lupi overseeing the curation of the historical collection. The focal point of the museum is the main gallery, a glass atrium that connects via Ceresio with via Bramante. The complex includes the adjacent palazzo and also houses the headquarters of the ADI, the museum conservatory and offices, a cafeteria, bookshop and meeting spaces. It is bordered by the Fabbrica del Vapore cultural centre, an arts exhibition and research facility designed by Herzog & de Meuron.
See also
List of design museums
References
External links
ADI Design Museum Compasso d'Oro (brief documentary film by RAI Culture television)
2001 establishments in Italy
Museums in Milan
Design museums
Industrial design collections
Italian design
Product design | ADI Design Museum | [
"Engineering"
] | 327 | [
"Product design",
"Design"
] |
74,403,192 | https://en.wikipedia.org/wiki/Neuch%C3%A2tel%20gas%20turbine | The Neuchâtel gas turbine is the world's first electric power-generating gas turbine to go into commercial operation. It was designed and constructed by Brown, Boveri & Cie and installed in 1939 at the municipal power station in Neuchâtel, Switzerland. The gas turbine was in service as a standby unit from 1940 until its retirement in 2002.
Design and development
Brown, Boveri & Cie (BBC) first became involved with gas turbines when they began building turbo-compressors in collaboration with the French industrialist Auguste Rateau. The first machine built under this agreement was a 25 impeller, three casing centrifugal compressor for the experimental 1906 Armengaud-Lemale gas turbine.
BBC worked on a number of experimental gas turbine projects in the 1910s and 20s. BBC's gas turbine collaborations included Holzwarth's explosion turbines and a two-stroke version of Herbert Humphrey’s Humphrey pump which would have been used for power generation (a so called “wet gas turbine”). None of these early gas turbine experiments produced a commercially viable product.
In the 1930s BBC developed the commercially successful Velox boilers. Velox boilers use an axial flow air compressor driven by a flue-gas turbine to allow rapid heating of a steam boiler. The first Velox boiler was installed at the Mondeville steel works in France in 1932.
In 1936, BBC built the world’s first constant flow industrial gas turbine for the Sun Oil refinery in Marcus Hook, Pennsylvania. The early BBC gas turbine sets were essentially Velox boilers with the steam component removed. The Marcus Hook turbine was used for the catalyst regeneration cycle of the Houndry oil refining process and had a high enough compressor efficiency that the turbine produced a continuous power surplus that was used for electricity generation.
BBC's first opportunity to build a gas turbine solely for the purposes of electrical power generation came in 1938, when the Services Industriels de la Ville de Neuchâtel placed enquiries for an emergency power generator to be placed in a bomb-proof cavern. In the late 1930s, heavily protected emergency power generators were being ordered by utilities across Europe to ensure continued electrical supplies in the event of aerial bombardment. BBC's proposal for a 3,000 RPM, 4 MWe gas turbine was accepted. The key concerns for this application were limited space and fast starting times rather than efficiency, which suited the early open cycle gas turbines.
Assembly of the Neuchâtel gas turbine set was completed in BBC's Baden works by the summer of 1939. Full load tests took place on 7 July under the supervision of Professor Aurel Stodola with representatives from the Swiss Association of Steam Boiler Proprietors, the Swiss Association of Electrical Engineers and the Swiss Federal Material Testing Laboratories. Power output was recorded at 4,021 kW with a cycle efficiency of 17.38%. Prior to its installation in Neuchâtel, the gas turbine was exhibited at the Swiss National Expo in Zürich.
Operating history, retirement and preservation
The Neuchâtel gas turbine went into service early in 1940. In 1988 the gas turbine was awarded "mechanical landmark" status by the American Society of Mechanical Engineers (ASME) in recognition of its historical significance.
Over its 62 years in service the Neuchâtel gas turbine accumulated 7,283 operating hours and 1,908 starts. In 2002 the plant was permanently closed following damage to the gas turbine set's alternator.
In 2007, Alstom (who had acquired BBC's turbine business in 2000) relocated the Neuchâtel gas turbine to their facility in Birr, Aargau where it was restored and put on display.
References
Brown, Boveri & Cie
Gas turbines
History of electrical engineering
Turbo generators
Power stations | Neuchâtel gas turbine | [
"Technology",
"Engineering"
] | 767 | [
"Electrical engineering",
"History of electrical engineering",
"Engines",
"Gas turbines"
] |
74,403,527 | https://en.wikipedia.org/wiki/George%20Harold%20Winterbottom | George Harold Winterbottom was an Edwardian business magnate, who dominated global bookcloth manufacture for bookbinding, making him "one of the wealthiest men of England". Bookcloth took over from more expensive materials like silk and leather as the dominant hardcover bookbinding material in the early 19th century, revolutionising the manufacture and distribution of books. Winterbottom seized the opportunity to effectively monopolise the production and supply of high quality bookcloth, which facilitated a country life for himself as a gentleman farmer and philanthropist.
Early life
Winterbottom was born in Bury in 1861, the youngest son of Archibald Winterbottom, a self-made entrepreneur from a Huddersfield wool milling family, and Helen (née Woolley), daughter of a Mancunian cotton manufacturer. There is some uncertainty where Winterbottom was educated, but at the age of seventeen, he was apprenticed to the family business (Archibald Winterbottom (Co.)) with his older brother William.
Business magnate
In 1879 Winterbottom began his apprenticeship in his father's cotton mill, Victoria Mills. According to contemporary accounts, it was clear from the outset that he was determined to learn everything possible about bookcloth production, which was to prove crucial in running the company when his father died five years later. Following two years of direct tutelage from his father, Winterbottom was brought formally into the family business with his brother William Dickson Winterbottom in 1881. When Archibald Winterbottom died in 1884, the brothers continued to run Archibald Winterbottom (Co.) as executors until probate was released in 1887, and Archibald Winterbottom and Sons (AW&S) was created. Winterbottom focused his attention on stabilising the bookcloth market and exploring new business, while his brother consolidated existing production, principally from Victoria Mills.
The Winterbottom Book Cloth Company
Intense competition between bookcloth manufacturers in what was a relatively small market, had been building in Britain long before AW&S was formed. Bookcloth production from Victoria Mills was strong but uneconomic as a result of severe downward pressure on prices caused by the intense competition. Winterbottom opened negotiations with his three main rivals at the peak of the price war in 1885, in an effort to control pricing by creating a syndicate, while maintaining overall production quality. After years of damaging predatory pricing, the remaining companies were struggling to survive but it was an uneven struggle as AW&S losses from the bookcloth business were to some extent offset by their thriving tracing cloth business. By 1890, Winterbottom had managed to align a syndicate to control prices consisting of the top four bookcloth companies, including some smaller operators in England. But Winterbottom saw an opportunity to extend his reach beyond Britain, turning his attention to the United States and to Germany as potential export markets. He travelled in the same year to both countries, taking out patents for book binders' cloth even though bookcloth production was already thriving in both countries (ibid.).
In 1891, thirty-eight years after the launch of their father's bookcloth business, Winterbottom had absorbed nine of his business competitors in England, the US and Germany by merging them into The Winterbottom Book Cloth Company Ltd. (WBCC), installing himself as chairman. At the age of thirty in the space of four years, with ruthless efficiency, Winterbottom had ensured that The WBCC dominated bookcloth trade in Britain and America for the next century and that his brand became the global standard for bookbinding.
United States bookcloth production
Since its inception in 1823, the introduction of bookcloth in the US was largely synchronous with England's, facilitated in the US by the introduction of case construction methods of bookbinding, which led to progressive mechanisation. But the US continued throughout the 19th century to depend on England for imported bookcloth from companies that included, among others, Archibald Winterbottom (Co.). Local manufacturers of bookcloth like the Staten Island Dye Works, began producing bookcloth sometime before 1877 but were forced out of the bookcloth business in 1883 by cheaper imports from England. Staten Island Dye Works reverted to only dyeing but were keen to return to bookcloth and wrote to Winterbottom in 1890 to offer a partnership. The offer was declined, however, as Winterbottom was already making moves of his own in the US.
Following the failure of the bookcloth industry in the US in 1883, the United States Government formed the view that it was desirable for the American book trade to have at least one local supplier of bookcloth. This view was supported by a group of New England cotton merchants, who opened Interlaken Mills, in Arkwright, Rhode Island with the express intent of supplying bookcloth to the local printing and bookbinding industry. As production began, Interlaken Mills gradually obtained an increasing share in the US market for bookcloth, threatening the dominance of importation from Winterbottom. By the end of the decade, Interlaken Mills though dominant, was being undercut by local merchants with inferior quality bookcloth.
Rather than engaging in another damaging price war like that in England, Winterbottom decided to bring Interlaken Mills into his emerging syndicate. In 1890, he filed two patents in the US for bookbinders' cloth as the assignee on behalf of AW&S. Winterbottom then travelled to America and bought Interlaken Mills, in an apparently amicable takeover, which allowed Interlaken to continue trading under its own name with its own board of directors. Winterbottom himself became very friendly with Interlaken managers and their families (ibid.), visiting every two to three years from 1892 to 1913, accompanied by his wife Minnie in the early years, building a mutually beneficial relationship between British and US operations, which endured for eighty years, long after Winterbottom himself had died.
Winterbottom continued to grow and consolidate the business in Rhode Island, fending off competition in 1904 with record sales over the next ten years, earning him large sums of money. Twenty-two years after having taken over operations in America, Winterbottom booked passage with a group of friends to New York aboard Titanic but was delayed by business at home, forcing him to postpone his passage by a week. Winterbottom travelled to New York aboard Adriatic on April 18, 1912, three days after Titanic had gone down with the loss of 1,500 lives. Adriatic returned to Liverpool on the 2nd of May with some of the surviving crew and management of Titanic.
Consolidation
Bringing operations from the US and Germany into the WBCC corporate group resulted in a near global monopoly, which stabilised prices but risked the disaffection of book manufacturers who had previously been able to shop around to get the best price for their businesses. Winterbottom took a conciliatory approach to dissent, visiting customers to negotiate deals and easing them into compliance. Lawyers were also kept busy ensuring that partners remained aligned, making minor changes to the original agreement or by threatening his larger partners with his own resignation.
Winterbottom would tolerate no compromise on quality control, with all production standards set by Victoria Mills, which were subsequently applied to the ten other factories in the Group. Significant investment in new machinery and changes in production methods were required at Interlaken Mills and the Bamberg Works, keeping up with emerging technologies and markets, while maintaining strict quality control. Winterbottom's uncompromising attention to detail and rejection of new stock that didn't measure up, ensured consistency within all the Group's operations. This was not always easy to apply, particularly in Germany, where he was forced to make changes to staffing to ensure strict compliance with his restrictive confidentiality controls, which preserved corporate intellectual property rights and enforce strict competitive intelligence protocols.
Exports made a vital contribution to Winterbottom's net income. By the turn of the century, a quarter of the WBCC’s customers were from overseas, with bookcloth and tracing cloth exports from Salford going to at least 50 countries. The US Government commissioned a study on the industry in 1899 and found that world trade was divided largely between Winterbottom and two or three German firms, who also sourced their best grades from Manchester. Following fifteen years securing world markets through forging new alliances and mergers, in which the merger had restored profitability to the industry while returning huge net profits year-on-year, Winterbottom had restored substantial profitability to his production, and could step back from the business and consider a change of pace. As chairman and managing director of WBCC, he continued to fend off competition, either by acquiring the competitor or by putting them out of business and buying their patents. World War I presented Winterbottom with personal as well as business challenges, particularly to his German assets, but he maintained his global pre-eminence, creating new companies such as the Manchester Book Cloth Company, to take advantage of new markets and new technology in water proofing, as well as new synthetic materials.
Gentleman farmer
In the late 1880s Winterbottom frequently travelled to London from Manchester, securing deals to underpin his growing global interests. Over the same period that he was confronting business adversaries with ruthless efficiency around the world, he was also pushing for social reform closer to home, providing medical care for the poor, arguing in public for improved conditions for workers and their families. In 1887 while in London, he started an affair with Louisa Elizabeth Ferguson (née Babb), better known in the West End by her stage name Minnie Byron, a Mezzo Soprano celebrated for her stage roles in variety and Victorian burlesques. Two years later, they had their first son together, George Harold Ferguson, followed by a second, Oscar, in 1891. Winterbottom and Minnie married immediately after her divorce from Ferguson came through at the end of 1891 and a third son Dudley was born in 1892. Winterbottom sought to hide the illegitimacy of their first two sons by having all three christened "Winterbottom" in a remote country parish outside of Poynton where he was living in 1894. As far as society at large was concerned, Winterbottom was married to Louisa Elizabeth Ferguson in 1887, effectively concealing any hint of scandal.
Winterbottom and Minnie spent the next ten years alternating between living in London and Manchester, and travelling together for extended breaks to the US in 1892, 1894 and 1896 aboard Majestic. By 1898, the couple had found their future home: a boarding school in Northamptonshire whose lease was coming up for renewal. In 1899, Winterbottom purchased Horton Hall and together, they set about adding a new wing, and completely re-furbished the interior. Minnie gave birth to a daughter in London on March 18, 1901, but died of puerperal fever 10 days later. Winterbottom was traumatised by her death and dedicated himself to completing their dream at Horton in her memory. A single parent with the responsibility for six children, as well as a stately home of some 4,000 acres, landlord to tenant farms and the villages of Horton, Hackleton, Piddington and Preston Deanery, Winterbottom created a new life for himself as a gentleman farmer, moving his family to Horton as early as May 1902, where his daughter was christened.
Winterbottom opened his gates to the general public in May 1902 for the first of many charity fêtes and galas to be held at Horton Park, which became annual events by 1930. He immersed himself in local administration, sitting on committees, organising and hosting charity events, in support of the well-being of his tenantry and those who worked directly for him, and was actively involved in local politics (as a free-trader), with strong ties to his Unitarian upbringing. Winterbottom was elected High Sheriff of Northamptonshire in 1906, elected a Magistrate in the same year, sitting on the Grand Jury of Assizes for Northamptonshire, to which he was re-elected every year until his last, and was elected President of the Citizens' Corps at the outbreak of war in 1914.
In 1913, 12 years after the death of his first wife, Winterbottom married Georgina McLeod, the daughter of a Scottish cleric, and had two more sons, Ian and Alistair.
Agriculture
In 1902 Winterbottom set about turning his land into a viable business with the same vigour he had applied to bookcloth by studying agriculture. He began by selling off excess woodland and by breeding Shire horses from his own stables, which he continued for the rest of his life. By 1909, with his eye for quality control, Winterbottom's sheep were producing more than 500 fleeces per year, fetching the highest prices in the county. By 1913, he diversified into cattle, choosing carefully selecting Friesian stock for milk production. During World War I as part of the war effort, he was able to sell off excess livestock and began ramping up wheat production, making up for a shortage of labour by innovating new machinery imported from America. At the end of the war, he expanded his Friesian breed, making Winterbottom a household name among breeders with his two celebrated herds. Apart from an unknown number of tenant farms, in 1927, Winterbottom employed 60 full-time farm workers on his land.
Legacy
As a child, Winterbottom had always been a keen sportsman, playing cricket at school, at County level since his early twenties, and as an "Old Player" at Horton, sponsoring annual matches with the local constabulary. In 1908, Winterbottom donated a cricket ground and built a thatched pavilion for the newly formed Horton House Cricket Club, which thrives today, a living legacy. As a child, he also had a strong artistic flair and had apparently wanted to pursue a career as a painter, which was denied to him. Instead, he supported other artists with commissions, most notably a sequence of large murals by Frank Brangwyn for Horton Hall, most of which are now on public display at the Dunedin Public Art Gallery, and which continue to mystify and intrigue art historians.
Arguably, Winterbottom's greatest achievement was securing a multilateral agreement following protracted negotiations with all the big producers of bookcloth in both the UK, the US and Germany, leading to the formation of the Winterbottom Book Cloth Company in 1891, which dominated the global market during the late 19th Century and through the first half of the 20th century. The relentless business magnate who personified his business ventures, existed simultaneously with the more pastoral gentleman farmer, who projected "a quiet interest in the County". Winterbottom's contribution to expanding the manufacture and distribution of books around the world were concealed partly by his highly secretive approach, and partly because the formative role played by bookcloth in popularising edition publishing is not widely known outside of the industry.
Hundreds of mourners attended Winterbottom's funeral, spilling out into the churchyard in groups, and lining the road between Horton Hall and the churchyard of St. Mary's church, where he is interred with his first wife Minnie.
Notes and references
Notes
References
Cloth merchants
Bookbinders
Industrialists
British businesspeople
Cotton industry in England
English Unitarians
Bookbinding
Book arts
Book design
Book publishing
Graphic design
Paper art
Print production
People from Manchester
English art collectors
English landowners
19th-century English farmers
20th-century English farmers | George Harold Winterbottom | [
"Engineering"
] | 3,134 | [
"Book design",
"Design"
] |
74,404,005 | https://en.wikipedia.org/wiki/House%20demolition%20in%20Ethiopia%20%282019%E2%80%93present%29 | Many buildings have been demolished by the government of Ethiopia under Prime Minister Abiy Ahmed since early 2019, with 12,000 homes planned to be demolished for the purpose of rebuilding urban sprawl. The project was targeted toward Addis Ababa and Oromia, in the towns of Sebeta, Buraryu, Lagatafo Lagadadi, Sululta, Ermojo, and Gelan. Residents have criticized the government demolition, claiming they paid taxes to the government properties, and the government is illegally taking undue advantage to confiscate for the Oromia government.
The house destruction has led to violence and protests in some areas. The Amhara Association of America claims that Oromia authorities have used house demolition to displace, assault and detain ethnic Amharas between 9 January and 31 January 2023.
History
Since early 2019, the Ethiopian government under Abiy Ahmed administration begun large-scale house demolition that deemed "illegal property" in Addis Ababa and the Oromia Region in the area of Sebeta, Buraryu, Legetafo, Legedadi, Sululta, Ermojo, and Galan towns, with 12,000 houses destroyed by the government, which led to further unrest in the country. On 19 February 2019, bulldozers were raid into Legetafo area and demolished 3,000 homes, leading to thousands homelessness and ruin business activities. Mayor of Legetafo Legedadi Habiba Sirajs supported the demolition as a necessary steps corresponding to the 2017 master plan, which was part of urban strategies. According to a 29 April 2020 report released by Amnesty International, at least 1,000 people left homeless amid COVID-19 pandemic, mostly laborer over three weeks.
According to the Ethiopian Human Rights Council, houses in Yeka and Bole districts commonly demolished. Residents allege that they paid taxes and the demolition is "illegal to take advantage for Oromia government". Liliana Farha, the U.N. Special Rapporteur for Adequate Housing, told her concern over the house demolition in Legetafo and Legedadi, stating "The rapporteur will be investigating this issue and reminds all actors involved that forced evictions constitute an egregious violation of the right to housing." Activist Jawar Mohammed said that the government is irresponsible to demolish resident houses because they do not offer sufficient housing for them, after which the residents built "moon houses", a house illegally built overnight. The victims often targeted toward residents with low income economy. The Ethiopian Institution of the Ombudsman (EIO) criticized the government action. Chief Executive Ombudsman of EIO, Endale Haile spoke on Ahadu Radio that the government demolition campaign is indiscriminate regardless of people's conditions to have acquire homes.
As of February 2023, about 80% houses would be wiped out according to information gathered by the city's administration. Churches and mosques have also been targeted. On 26 May 2023, Ethiopian Muslims protested near the Grand Anwar Mosque to protest the government's decision to destroy 30 mosques in the newly established "Sheger City", formerly Oromia Special Zone Surrounding Finfinne. The Addis Ababa Federal Police stormed the protesters, and in response the protesters threw stones, which killed two people. The Ethiopian Islamic Affairs Supreme Council and the Oromia Region Islamic Affairs Council condemned the police action against the protesters. According to Amhara Association of America, the Oromia authorities continued house demolition that belonged to ethnic Amhara, started arbitrary arrests, and tortured prisoners between 9 January and 31 January 2023. In March 2024, the government under Addis Ababa City Administration relaunched demolition in Piassa. Many historical sites has been razed, including cafés, shops, bar and restaurants and jewelries houses. From 2024, the Addis Ababa City Corridor Project was launched to upgrade key routes and improve connectivity among the corridors. It was expected to be completed in 2025.
See also
2023 in Ethiopia
References
Ethiopian civil conflict (2018–present)
2019 in Ethiopia
2020s in Ethiopia
Abiy Ahmed
Housing in Ethiopia
Destruction of buildings
21st century in Addis Ababa
Controversies in Ethiopia
Attacks on buildings and structures in Ethiopia
History of urban planning
Urban planning in Ethiopia | House demolition in Ethiopia (2019–present) | [
"Engineering"
] | 881 | [
"Destruction of buildings",
"Architecture"
] |
74,408,167 | https://en.wikipedia.org/wiki/HD%2028780 | HD 28780, also known as HR 1440, is a solitary white-hued star located in the northern circumpolar constellation Camelopardalis. It has an apparent magnitude of 5.91, making it faintly viisble to the naked eye under ideal conditions. Gaia DR3 parallax measurements imply a distance of 488 light-years, and it is currently drifting closer with a heliocentric radial velocity of . At its current distance, HD 28780's brightness is diminished by 0.33 magnitudes due to interstellar extinction and it has an absolute magnitude of +0.26.
HD 28780 has a stellar classification of A1 V, indicating that it is an ordinary A-type main-sequence star that is generating energy via hydrogen fusion at its core. However, Abt & Morell (1995) gave a classification of A1 III, indicating that it is an evolved A-type giant star that has exhausted hydrogen fusion at its core. At the age of 300 million years, HD 28780 has completed 80.2% of its main sequence lifetime. It has 2.48 times the mass of the Sun and a slightly enlarged radius 3.79 times larger than the Sun's. The star radiates 101 times the luminosity of the Sun from its photosphere at an effective temperature of . HD 28780 is metal deficient with an iron abundance 61.7% that of the Sun's ([Fe/H] = −0.21) and unlike most hot stars, it spins modestly with a projected rotational velocity of .
References
A-type main-sequence stars
Camelopardalis
BD+63 00515
028780
021452
1440 | HD 28780 | [
"Astronomy"
] | 353 | [
"Camelopardalis",
"Constellations"
] |
74,408,247 | https://en.wikipedia.org/wiki/Reversible%20Hill%20equation | The classic Monod–Wyman–Changeux model (MWC) for cooperativity is generally published in an irreversible form. That is, there are no product terms in the rate equation which can be problematic for those wishing to build metabolic models since there are no product inhibition terms. However, a series of publications by Popova and Sel'kov derived the MWC rate equation for the reversible, multi-substrate, multi-product reaction.
The same problem applies to the classic Hill equation which is almost always shown in an irreversible form. Hofmeyr and Cornish-Bowden first published the reversible form of the Hill equation. The equation has since been discussed elsewhere and the model has also been used in a number of kinetic models such as a model of Phosphofructokinase and Glycolytic Oscillations in the Pancreatic β-cells or a model of a glucose-xylose co-utilizing S. cerevisiae strain. The model has also been discussed in modern enzyme kinetics textbooks.
Derivation
Consider the simpler case where there are two binding sites. See the scheme shown below. Each site is assumed to bind either molecule of substrate S or product P. The catalytic reaction is shown by the two reactions at the base of the scheme triangle, that is S to P and P to S. The model assumes the binding steps are always at equilibrium. The reaction rate is given by:
Invoking the rapid-equilibrium assumption we can write the various complexes in terms of equilibrium constants to give:
where . The and terms are the ratio of substrate and product to their respective half-saturation constants, namely and and
Using the author's own notation, if an enzyme has sites that can bind ligand, the form, in the general case, can be shown to be:
The non-cooperative reversible Michaelis-Menten equation can be seen to emerge when we set the Hill coefficient to one.
If the enzyme is irreversible the equation turns into the simple Michaelis-Menten equation that is irreversible. When setting the equilibrium constant to infinity, the equation can be seen to revert to the simpler case where the product inhibits the reverse step.
A comparison has been made between the MWC and reversible Hill equation.
A modification of the reversible Hill equation was published by Westermark et al where modifiers affected the catalytic properties instead. This variant was shown to provide a much better fit for describing the kinetics of muscle phosphofructokinase.
References
Enzyme kinetics
Pharmacology
Chemical kinetics
Catalysis | Reversible Hill equation | [
"Chemistry"
] | 550 | [
"Catalysis",
"Pharmacology",
"Chemical reaction engineering",
"Enzyme kinetics",
"Medicinal chemistry",
"Chemical kinetics"
] |
74,408,466 | https://en.wikipedia.org/wiki/Fascine%20mattress | A fascine mattress , literally sink piece), is a large woven mat made of brushwood, typically willow twigs and shoots, used to protect riverbeds and other underwater surfaces from scour and erosion. They are similar in construction to a fascine, but are primarily used for hydraulic engineering works, typically to strengthen the banks of rivers and streams, as well as coastal structures like revetments and groynes.
Modern fascine mattresses utilise a layer of geotextile in order to fulfill the competing requirements of water permeability balanced with the need to be impervious to sand. Prior to the advent of synthetic geotextiles in the 1960s, a layer formed from reeds was incorporated to make the fascine mattress sand-tight.
Fascine mattresses have been used worldwide, but are particularly common in The Netherlands, where significant expertise in their preparation and construction is available, and where the materials required for their construction are harvested in specially created plantations.
Historical background
have been used in The Netherlands for river and coastal engineering works since at least the 16th century, and were discussed extensively by Andries Vierlingh in his (English: Treatise on dike building), the manuscript of which was not published until 1920, and is now housed in the Nationaal Archief.
The materials for fascine mattresses in The Netherlands were traditionally harvested in osier beds along rivers such as The Merwede, particularly around the Biesbosch, where the materials were grown and coppiced in order to produce the mattresses. The towns of Werkendam and Sliedrecht are notable as centres of fabrication and construction expertise.
In the 16th century, dike workers in The Netherlands were often impoverished, taking on jobs under a day-rate contract. Dike building works were usually tendered in the month of March and often had to be completed by August, and fascine mattresses were a common feature of the work.
By the end of the 17th century, floating fascine mattresses had been introduced for closure works in the Netherlands, with the mattresses being assembled and then towed to the required location, where they were ballasted by rocks and then immersed by sinking. This technique was used as scour protection at the bed level, and the ability to stack layers of fascines on top of each other in the required location up to the level of low tide with this method made gradual closures possible.
In the mid to late 19th century, fascine mattresses were used across the Netherlands, including in works at Schellingwoude and the Sloedam, along with sections of embankments at the Hollands Diep and shore protection works in Westkapelle. Sections of the Rhine between Lobith and Pannerden were strengthened by fascine mattresses from 1851. Fascine mattresses were also used extensively in the construction of sections of the Amsterdam Ship Canal and the Port of Rotterdam. By the middle of the 1800s, engineering knowledge around fascine mattress installation had begun to be included in Dutch engineering textbooks.
By 1910, the town of Werkendam was home to 160 fascine mattress workers (), some of whom worked abroad. Their wages at the time ranged from 12 to 18 guilders per week. As Dutch dredging and hydraulic engineering contractors began to undertake works internationally, the workers earned up to 50 guilders per week overseas. Much of their income was spent on basic sustenance, with workers often living on the worksite in a hut or cabin. An average of eight months per year was spent at fascine mattress work, with the remaining four months (usually from November to March) spent on tasks such as coppicing and harvesting.
Preparation and construction (traditional)
The main component of a traditional fascine mattress is willow twigs, which are formed into a wattle. Willow timber has several properties that are important throughout the process of creating and sinking a fascine mattress, being flexible, robust, and buoyant. The manufacturing process of a traditional fascine mattress begins by winding rope around the willow in both directions using a machine, resulting in a lengthy roll known as a wattle.
Historically, a considerable number of skilled workers, known in the Netherlands as , were required to create wattles at a proprietary stand. Nowadays, with the use of machinery, this process is more efficient and allows for adjustments to the thickness and length of the wattle as required.
The mattress is assembled on a patch of ground adjacent to the water, and once the wattle is complete, the mat is towed to the desired location and sunk to the bed using dumped stones. The bottom layer of a traditional fascine mattress is a lattice structure composed of wattle, spaced around one metre apart. On top of this base are arranged two crisscrossing layers of willow twigs, referred to as the first and second brush layers.
To ensure the fascine mattress is sand-tight, a layer of reed is inserted between these brush layers. Occasionally, for added stability, a third brush layer may be placed above the second. Following this, an upper lattice of wattle is installed to secure the entire structure.
The cohesion of the mattress is then reinforced by tightly binding the upper and lower lattices together using ropes. In The Netherlands, it is common to add , a type of fencing, to the top of the fascine mattress in order to prevent the stones dumped onto it from rolling off during underwater immersion.
Timber stakes are used to mark out a working grid, indicating the precise positions for the layout of the wattle. Then, the brushwood is layered between the wattles, followed by the addition of the second brush layer, before the top layer is positioned. By this stage, the fascine mattress is around half a metre thick. Finally, the bindings are tightened to create a coherent, unified structure ready for installation.
Construction (modern)
The construction of the Delta Works, prompted by the effects of the North Sea flood of 1953, was of such a vast scale that tremendous quantities of brushwood would have been required to utilise traditional fascine mattresses across all of the Delta Works projects. As a result, the department of Rijkswaterstaat decided to undertake research and experiments at the Waterloopkundig Laboratorium, to investigate the possibility of improving the traditional mattress and reducing the quantity of brushwood required.
This work coincided with the advent of synthetic geotextiles in the late 1950s and early 1960s, and traditional fascine mattresses began to reduce in popularity, with use being made of woven polypropylene fabrics in place of the reed underlayer. Traditional fascine mattresses are however still used, with their application often limited to locations where synthetic materials and plastics are discouraged or prohibited for environmental reasons.
For the Delta Works, 'block mat' fascine mattresses consisting of a fabric with concrete blocks attached were rolled up and immersed by unrolling the mat with a special ship, the Cardium, during the construction of the Oosterscheldekering. These mattresses were reinforced with steel cables to mitigate the effects of tension.
Modern fascine mattresses are made using a woven polypropylene fabric which is water-permeable, sand-tight and contains pre-woven loops. The loops allow the fabric to be attached to a wattle grid using a rope, without the need to create holes.
These modern mattresses are much thinner than traditional mattresses, with a longer design life. The function of the wattle grid is to provide sufficient buoyancy and rigidity to the fabric during the sinking process. The absence of a wattle grid precludes the underlayer fabric from being uniformly flat across the riverbed or underwater surface onto which it is placed. The grid also prevents broken stone from rolling off, particularly when used on revetments or sloping surfaces.
Placement
Fascine mattresses are immersed by dumping stone or rock onto the surface, causing it to sink to the bottom. In tidal waters, this must occur at a time when there are no (or very low) tidal currents, usually at slack water. Once the fascine mattress is in place, the underlying bed is protected from erosion by the flowing water and deformation of the riverbed or bank is negated.
The dumped stones ensure that the mattress remains in place and provides protection against wave action on banks. The design life of a fascine mattress can be as much as 100 years. In the past, a fascine mattress was immersed using skilled labour placing stones on it by hand, such as during the construction of the Afsluitdijk. It is important that the stones are applied evenly, and that everyone is clear of the fascine mattress at the time of sinking. Modern mattresses are placed using civil engineering plant such as crane barges, long reach excavators and, in deeper water, side stone-dumping vessels.
Placement of a mattress in conditions where there is a flowing current is nearly impossible with this method, however placement using a pair of pontoons and a side-stone dumping vessel is possible. In the latter situation, the mattress is connected to a pair of sinking beams (hollow tubes), which are filled with water at the appropriate time to sink the mattress. After immersion, these sinking beams are disconnected from the mattress, filled with air, and recovered.
Examples of use
Fascine mattresses have been used in projects across the world, and their use in The Netherlands has been extensive, including projects such as the Afsluitdijk and Delta Works projects such as the Zandkreekdam, Volkerakdam, Brouwersdam, and Grevelingendam. The technique was also used in Zeeland for dike reinforcements in the Eastern Scheldt and in the construction and extension of the piers of IJmuiden and the widening of the North Sea Canal.
Extensive use of fascine mattresses was made during the emergency recovery works following the Inundation of Walcheren, with the Gerrit Visser of Van Oord decorated by the authorities in Zeeland for supervising the immersion of 36 fascine mattresses over a total area of 52,700 square metres during the works. Visser is portrayed as the character Klaas Otterkop in A. den Doolaard's non-fiction novel Het verjaagde water.
Application outside the Netherlands
The ideas of Andries Vierlingh, as set out in his , were used in the 16th century by Cornelius Vermuyden for his drainage works in England. Around 1750, the Dutch engineer Cornelis Janszoon Meijer introduced fascine mattresses for bed protection works in Italy.
At the request of the Japanese government in the 1870s, a number of Dutch hydraulic engineers were invited to improve hydraulic engineering works in Japan. These engineers included Cornelis Johannes van Doorn, who was in charge of renovation work on the Tone, Edo and Yodo Rivers, along with works on the Asaka Irrigation Canal in Fukushima Prefecture and the Nobiru Port in Sendai Bay.
Van Doorn introduced fascine mattresses and during the period 1872 – 1880, and the art and science of making fascine mattresses subsequently became known in Japan as the Westerwiel method, named for one of the Dutch , and is now known in Japan as the "Japanese traditional method".
In 1849, the British engineer Charles Blacker Vignoles visited Dutch contractors Aart Schram and Leendert Martinus Prins in Sliedrecht, and arranged for them to travel to Kyiv and install fascine mattresses as scour protection to the piers of the Nicholas Chain Bridge, which had suffered extensive damage during construction.
Other examples of the use of fascine mattresses outside the Netherlands in the 19th century include riverbank improvement works by James Buchanan Eads on the southern Mississippi, using fascines made from Poplar trees and shoots grown on the banks above Baton Rouge, and protection works using fascine mattresses made from mangroves on the coastline of British Guiana.
Fascine mattresses continue to be used internationally, including for bed protection works in Bangladesh, Vietnam, India, and Laos, particularly in the framework of development aid projects. One benefit of the method is that whilst these systems are labour intensive, they do not require significant capital expenditure, which is therefore an advantage in developing countries.
See also
Coastal engineering
Fascine
References
Further reading
Coastal engineering
Civil engineering
Hydraulic engineering
Basket weaving | Fascine mattress | [
"Physics",
"Engineering",
"Environmental_science"
] | 2,567 | [
"Hydrology",
"Coastal engineering",
"Physical systems",
"Construction",
"Hydraulics",
"Civil engineering",
"Hydraulic engineering"
] |
74,409,613 | https://en.wikipedia.org/wiki/1T-LSD | 1T-LSD (N1-(thiophene-2-carbonyl)-lysergic acid diethylamide, SYN-L-021) is an acylated derivative of lysergic acid diethylamide (LSD), which has been sold as a designer drug. It was first identified in Japan in 2023 on blotter paper misrepresented as containing 1D-LSD, but which on analysis was determined to contain 1T-LSD instead. It was also detected in Germany around the same time.
See also
1B-LSD
1P-LSD
1V-LSD
1DD-LSD
1T-AL-LAD
References
Designer drugs
Lysergamides
Prodrugs
Serotonin receptor agonists
Thiophenes | 1T-LSD | [
"Chemistry"
] | 172 | [
"Chemicals in medicine",
"Prodrugs"
] |
74,409,878 | https://en.wikipedia.org/wiki/DAPNET | DAPNET (Decentralised Amateur Paging Network) is a free global paging network created and maintained by amateur radio enthusiasts. Messages can be received on commercially available pagers that support the POCSAG protocol and are tuned to the appropriate frequency.
History
A similar ham radio project called FunkrufMaster was quite popular around 2000. It was based on AX.25-technology and the former Packet Radio Network. Because of the upcoming HAMNET- and IP-Protocol era, a successor was needed. Members of the ham radio activity group at RWTH Aachen University designed and developed DAPNET from scratch as a modern software approach. As of March 2018, over 90 transmitters were already in permanent operation, and the coverage area included parts of Germany, the Netherlands, Belgium, and Switzerland, with Raspberry Pi-based personal hotspots extending coverage around the world.
Technical specifications
The recommended frequency for DAPNET is 439.9875 MHz, which is part of the 70-centimeter band dedicated to amateur radio use. The transmitters are networked, some via HAMNET, some via the Internet. The standard paging protocol POCSAG is used for message transmission. For a low-power transmitter you can use Raspberry Pi with and MMDVM-modem installed, and to make the coverage area several miles, a radio amplifier needs to be added to its output. The coverage area of the transmitter can be up to 20 km (12 miles), depending on the terrain and the height of the antenna.
Receivers
Skyper and AlphaPOC pagers are particularly popular for receiving messages. They can be easily tuned to the desired reception frequency and also offer many other possibilities, such as receiving bulletins - messages sent to all recipients. However, other brands of pagers can be customized accordingly or Flipper Zero can be used.
Messages can be sent via a multilingual website as well as Android and iOS apps.
References
External links
hampager.de
Radio paging
Digital amateur radio | DAPNET | [
"Technology"
] | 410 | [
"Wireless networking",
"Digital amateur radio",
"Radio paging"
] |
74,410,381 | https://en.wikipedia.org/wiki/Weather%20of%201985 | The following is a list of weather events that occurred on Earth in the year 1985. The year began with a La Niña. The most common weather events to have a significant impact are blizzards, cold waves, droughts, heat waves, wildfires, floods, tornadoes, and tropical cyclones. The deadliest weather event of the year was the Ethiopia famine, which killed at least 400,000. The costliest weather event of the year was Hurricane Juan, which caused around $1.5 billion in damages in the Southern United States. Another significant weather event was the Bangladesh cyclone in May, which killed 11,069 people and damaged nearly 100,000 houses.
Deadliest events
Timeline
January
January 12–22 – Two cyclones, Eric and Nigel, make landfall within a week of each other in Fiji. Between 23 and 28 people were killed and at least $39 million in damages were caused.
February
February 1 – A winter storm in Alabama kills four people and builds up of ice, the largest amount since 1963.
March
March 2–9 – Cyclone Gavin kills three people in Fiji.
March 17 – An F3 tornado passes through Venice, Florida kills two people and causes $25 million in damages.
April
April 5 – An F2 tornado near Tilden, Illinois kills one person.
April 9 – Two tornadoes, one in Foshan, China and the other in Huaihua, kill 16 and 34 respectively.
April 21 – An F3 tornado in Throckmorton County, Texas kills three people.
April 28 – In Taylor County, Texas, an F2 tornado kills one.
May
May 22–25 – A cyclone makes landfall in Bangladesh, killing 11,069 people and damaging nearly 100,000 houses.
May 29 – An FU tornado in Kornos, Cyprus kills one person.
May 30 – A long-tracked tornadoes passes through Elkader, Iowa killing two and injuring 25.
May 31 – June 1 – A historic tornado outbreak involving 44 tornadoes caused 89 deaths and over $600 million in property damage across Ohio, Pennsylvania, New York, and Ontario.
12 people are killed and over 80 are injured in an F4 tornado in Albion, Pennsylvania
Another long-track F4 tornado kills 16 and injuries 125 in Crawford and Venango counties, Pennsylvania.
An F5 tornado tracks through Niles, Ohio and Wheatland, Pennsylvania, killing 18 people and injuring over 300.
An F4 tornado in Barrie, Ontario kills eight people and injuries over 100.
June
June 8 – A long tracked F3 tornado in northern Wisconsin kills three people and causes $25 million in damages.
June 8 – An F1 tornado in Menominee County, Michigan kills one person.
June 19–27 – Typhoon Hal causes between 38 and 68 deaths in the Philippines, China, Hong Kong, and Taiwan.
June 23 – July 1 – Between 49 and 89 people are killed and $80 million in damages are caused by Typhoon Irma in the Philippines and Japan.
July
July 21 – August 2 – Typhoon Jeff brings the heaviest rain to Shanghai in 23, killing 245 in China.
July 21–26 – Hurricane Bob leaves five dead in the Southern United States.
July 31 – August 10 – Flooding from Typhoon Kit kills twelve people in South Korea.
August
August 2 – While on approach to Dallas/Fort Worth International Airport, a microburst impacted Delta Air Lines Flight 191, killing 136 on board and one more on the ground died.
August 3 – An F1 tornado in Bari, Italy kills one person.
August 9–14 – Tropical Storm Lee kills 26 people in the Korean peninsula.
August 12 – An F2 tornado passes near New Lisbon, Wisconsin, killing two.
August 12–18 – Hurricane Danny kills five people along the Gulf Coast and the East Coast of the United States.
August 15–21 – Typhoon Mamie is responsible for between 35 and 44 deaths in Eastern China.
August 16 – An F2 tornado in Parrish, Alabama kills one.
August 16–25 – Typhoon Nelson kills at least 199 people in Taiwan and Eastern China.
August 24 – September 2 – Typhoon Pat kills 23 people in Japan.
August 28 – September 4 – Hurricane Elena kills nine people and caused $1.3 billion in damages in the Southern United States.
September
September 1–9 – Typhoon Tess leaves up to five dead in the Philippines and Hong Kong.
September 16–27 – 14 people are killed and $900 million in damages are caused by Hurricane Gloria in the East Coast of the United States.
September 22 – October 2 – Tropical Storm Andy kills 46 people in Vietnam.
September 30 – October 5 – 71 people are killed in East Asia from Typhoon Brenda.
October
October 6–7 – Flooding in Puerto Rico from a tropical wave kills 180.
October 7–9 – Flooding from Hurricane Waldo in Kansas kills one person.
October 11–17 – Typhoon Cecil kills 770 people in Vietnam and Thailand and damages or destroys 130,000 homes.
October 13–22 – Between 83 and 90 people are killed and 250,000 homes are damaged or destroyed by Typhoon Dot in the Philippines and Southeast Asia.
October 26 – November 1 – Hurricane Juan kills twelve people and causes $1.5 billion in damages across the Gulf Coast and interior United States.
November
November 3–8 – Flooding in the Mid-Atlantic region of the United States kills 62 people and causes $1.4 billion in damages.
November 15–23 – Hurricane Kate leaves 15 dead in Florida and Cuba while being one of only three hurricanes to make landfall in Florida in November.
November 18 – In Marion County and Baxter County, Arkansas, an F3 tornado kills three people causes $25 million in damages.
December
December 12 – Arrow Air Flight 1285R crashed shortly after takeoff from Gander International Airport, killing of 256 on board. Cold weather caused ice to build up on the wings of the DC-8, causing it to stall and crash into the forest.
Notes
References
Weather by year
Weather-related lists
1985-related lists
1985
1985 meteorology | Weather of 1985 | [
"Physics"
] | 1,205 | [
"Weather",
"Physical phenomena",
"Weather by year",
"Weather-related lists"
] |
74,412,682 | https://en.wikipedia.org/wiki/Stroke%20number | Stroke number, or stroke count (), is the number of strokes of a Chinese character. It may also refer to the number of different strokes in a Chinese character set. Stroke number plays an important role in Chinese character sorting, teaching and computer information processing.
Stroke numbers vary dramatically, for example, characters "丶", "一" and "乙" have only one stroke, while character "齉" has 36 strokes, and "龘" (three 龍s, dragons) 48 strokes. The Chinese character with the most strokes in the entire Unicode character set is "𪚥" (four 龍s) of 64 strokes.
Stroke counting
There are effective methods to count the strokes of a Chinese character correctly. First of all, stroke counting is to be carried out on the standard regular form (楷體, 楷体) of the character, and according to its stroke order, e.g., by writing the character stroke by stroke (in one's mind). On the same stroke, the tip of the pen can only move along a path once, not allowed to go back. Strokes "㇐" (heng, 横) and "㇀" (ti, 提) are written from left to right, and strokes "㇑" (shu, 竖), "㇓" (pie, 撇), "㇔" (dian, 点) and "㇏" (na, 捺) are written from top to bottom. And if needed, a standard list of strokes or list of stroke orders issued by the authoritative institution should be consulted.
If two strokes are connected at the endpoints, whether they are separated into two strokes or linked into one stroke can be judged by the following rules:
If the two strokes are connected in the upper left corner of a character or component, then separate them into two strokes, such as: 厂 (stroke order: ㇐㇓), 口 (㇑㇕㇐) and 日 (㇑㇕㇐㇐).
If they are connected in the upper right corner, then one stroke, such as: 口 (㇑㇕㇐), 月 (㇓㇆㇐㇐), 句 (㇓㇆㇑㇕㇐).
If they are connected in the lower left corner, then if it is a fully enclosed structure, then count as two separated strokes, such as: 口 (㇑㇕㇐), 回 (㇑㇕㇑㇕㇐㇐), 田 (㇑㇕㇐㇑㇐); if it is not fully enclosed, then count as one stroke, such as: 山 (㇑㇗㇑), 区 (㇐㇓㇔㇗), 葛 (㇐㇑㇑㇑㇕㇐㇐㇓㇆㇓㇔㇗) .
If they are connected in the lower right corner, then two strokes, such as: 口 (㇑㇕㇐), 回 (㇑㇕㇑㇕㇐㇐), 田 (㇑㇕㇐㇑㇐).
An important prerequisite for connecting two strokes into one is: the tail of the first stroke is connected with the head of the second stroke.
Some characters or components have the same shape in the China Mainland and Taiwan, but the numbers of strokes are different, such as "之 (Mainland China: ㇔㇇㇏, 3 strokes), 之 (Taiwan: ㇔㇀㇓㇏ 4)", "阝 (M: ㇌㇑, 2), 阝 (T: ㇇㇢㇑, 3)”.
The number of strokes of some characters are easy to be mis-counted, such as 凹 (㇑㇅㇑㇕㇐, 5 strokes), 凸 (㇑㇐㇑㇎㇐, 5), 鼎(㇑㇕㇐㇐㇐㇞㇐㇓㇑㇐㇑㇕, 12).
Distribution of characters
In the following, there are several tables of statistical data illustrating the distributions of Chinese characters among all stroke numbers of some representative character sets.
Chart of Standard Forms of Common National Characters (Taiwan)
Chart of Standard Forms of Common National Characters (常用國字標準字體表) is a standard character set of 4,808 characters issued by the Ministry of Education of Taiwan (ROC).
The stroke numbers of characters range from 1 to 32 strokes. The 11-strokes group has the most characters, taking 9.297% of the character set. On the average, there are 12.186 strokes per character.
List of Frequently Used Characters in Modern Chinese (Mainland)
The List of Frequently Used Characters in Modern Chinese (现代汉语常用字表) is a standard character set of 3,500 characters issued by the Ministry of Education of the People's Republic of China, 26 Jan 1988.
The stroke numbers of characters range from 1 to 24 strokes. The 9-strokes characters are the most, taking 11.857% of the character set. On the average, there are 9.7409 strokes per character.
List of Commonly Used Characters in Modern Chinese (Mainland)
The List of Commonly Used Characters in Modern Chinese (现代汉语通用字表) is also a standard character set issued by the Ministry of Education of the People's Republic of China. There are 7,000 characters, including the 3,500 characters in the List of Frequently Used Characters in Modern Chinese.
The stroke numbers of characters range from 1 to 36 strokes. The 9-strokes group has the most characters, taking 11.21% of the character set. On the average, there are 10.75 strokes per character.
Cihai
The following statistic data comes from an experiment conducted on all the 16,339 traditional and simplified characters of Cihai (, 1979).
The stroke numbers of characters range from 1 to 36 strokes. The 12-strokes group has the most characters, taking 9.505% of the character set. On the average, there are 12.7061 strokes per character.
Unicode Basic CJK Unified Ideographs
The Unicode Basic CJK Unified Ideographs is an international standard character set issued by ISO and Unicode, the same character set of the Chinese national standard 13000.1. There are 20,902 Chinese characters, including simplified and traditional characters from China, Japan and Korea (CJK).
The stroke numbers of characters range from 1 to 48 strokes. The 12-strokes group has the most characters, taking 9.358% of the character set. On the average, there are 12.845 strokes per character.
Characteristics
From the data of the previous tables, some valuable cross-table characteristics can be found:
Everybody knows that the average number of strokes per character of the simplified Chinese writing system is less than the traditional writing system, but is not likely to know how much less it is. And the data from the first two tables present a very useful reference: "9.7409 : 12.186" strokes per character is the ratio between the two standard frequently-used character sets of China mainland (simplified Chinese) and Taiwan (traditional Chinese).
According to the data of the second and third tables, the average number of strokes of the 3,500 frequently-used characters is 9.74, and the average number of strokes of the 7.000 commonly-used characters (a super set of the 3,500 characters) is 10.75. That means generally speaking, frequently-used characters have less strokes than less frequently-used characters.
The numbers of characters for each number of strokes are in normal distribution, i.e., high in the middle and gradually low in both sides, with the peak numbers of characters ranging between 9 and 12 strokes in the five tables. Here is an explanation: To be easy to read or recognize, the forms (or glyphs) of Chinese characters should be sufficiently differentiated from each other, and to be easy to write, the characters should be relatively simple. The former condition requires the number of strokes of a character not to be too small, while the latter condition requires the number of strokes not to be too large. Under the action of these two forces, the normal distribution is formed.
Stroke types
The term stroke number may also refer to the number of different strokes in the Chinese character writing system, or the number of stroke types in a stroke table.
How many types of strokes are there in Chinese characters? Scholars’ opinions are not entirely consistent. For example, for the purpose of Chinese teaching and reference book compilation, the categories are usually relatively small; from the perspective of calligraphy art and glyph design, there are much more. For example, stroke "shu (丨)" can be further divided into "long shu", "short shu", and "hanging needle shu", etc., and "pie (丿)" can be divided into "flat pie", "slant pie", and "vertical pie".
Five types
Current national standards such as "Stroke Orders of Commonly-used Standard Chinese Characters" and many reference books published in China mainland have adopted the five categories of
heng (横, 一), shu (竖, 丨), pie (撇, 丿), dian (点, 丶), zhe (折, 𠃍),
and stipulate the heng-shu-pie-dian-zhe order. In Hong Kong, Taiwan and some other places, people also use the order of dian-heng-shu-pie-zhe ()
Eight types
In this classification, Chinese strokes are divided into eight categories:
, , , , , , , .
Because the character "永" (yǒng, forever) happens to contain strokes similar to these eight types of stroke forms, this classification is also called the "Eight Principles of Yong".
Unicode CJK strokes
The Unicode CJK strokes list has 37 types of strokes, including the newly-added character subtraction at the end:
YES stroke alphabet
The YES Stroke Alphabet, which is employed by YES stroke alphabetical order, is a list of 30 strokes:
㇐ ㇕ ㇅ ㇎ ㇡ ㇋ ㇊ ㇍ ㇈ ㇆ ㇇ ㇌ ㇀ ㇑ ㇗ ㇞ ㇉ ㄣ ㇙ ㇄ ㇟ ㇚ ㇓ ㇜ ㇛ ㇢ ㇔ ㇏ ㇂.
For more details about Chinese character stroke types and stroke tables, please see Chinese character strokes#Stroke form.
See also
Chinese character strokes
Chinese characters
Modern Chinese characters
Notes
References
Chinese character components | Stroke number | [
"Technology"
] | 1,987 | [
"Components",
"Chinese character components"
] |
74,413,105 | https://en.wikipedia.org/wiki/Exception%20handling%20%28programming%29 | In computer programming, several language mechanisms exist for exception handling. The term exception is typically used to denote a data structure storing information about an exceptional condition. One mechanism to transfer control, or raise an exception, is known as a throw; the exception is said to be thrown. Execution is transferred to a catch.
Usage
Programming languages differ substantially in their notion of what an exception is. Exceptions can be used to represent and handle abnormal, unpredictable, erroneous situations, but also as flow control structures to handle normal situations. For example, Python's iterators throw StopIteration exceptions to signal that there are no further items produced by the iterator. There is disagreement within many languages as to what constitutes idiomatic usage of exceptions. For example, Joshua Bloch states that Java's exceptions should only be used for exceptional situations, but Kiniry observes that Java's built-in is not at all an exceptional event. Similarly, Bjarne Stroustrup, author of C++, states that C++ exceptions should only be used for error handling, as this is what they were designed for, but Kiniry observes that many modern languages such as Ada, C++,
Modula-3, ML and OCaml, Python, and Ruby use exceptions for flow control. Some languages such as Eiffel, C#, Common Lisp, and Modula-2 have made a concerted effort to restrict their usage of exceptions, although this is done on a social rather than technical level.
History
The earliest IBM Fortran compilers had statements for testing exceptional conditions. These included the IF ACCUMULATOR OVERFLOW, IF QUOTIENT OVERFLOW, and IF DIVIDE CHECK statements. In the interest of machine independence, they were not included in FORTRAN IV nor the Fortran 66 Standard. However since Fortran 2003 it is possible to test for numerical issues via calls to functions in the IEEE_EXCEPTIONS module.
Software exception handling continued to be developed in the 1960s and 1970s. LISP 1.5 (1958-1961) allowed exceptions to be raised by the ERROR pseudo-function, similarly to errors raised by the interpreter or compiler. Exceptions were caught by the ERRORSET keyword, which returned NIL in case of an error, instead of terminating the program or entering the debugger.
PL/I introduced its own form of exception handling circa 1964, allowing interrupts to be handled with ON units.
MacLisp observed that ERRSET and ERR were used not only for error raising, but for non-local control flow, and thus added two new keywords, CATCH and THROW (June 1972). The cleanup behavior now generally called "finally" was introduced in NIL (New Implementation of LISP) in the mid- to late-1970s as UNWIND-PROTECT. This was then adopted by Common Lisp. Contemporary with this was dynamic-wind in Scheme, which handled exceptions in closures. The first papers on structured exception handling were and . Exception handling was subsequently widely adopted by many programming languages from the 1980s onward.
Syntax
Many computer languages have built-in syntactic support for exceptions and exception handling. This includes ActionScript, Ada, BlitzMax, C++, C#, Clojure, COBOL, D, ECMAScript, Eiffel, Java, ML, Object Pascal (e.g. Delphi, Free Pascal, and the like), PowerBuilder, Objective-C, OCaml, Perl, PHP (as of version 5), PL/I, PL/SQL, Prolog, Python, REALbasic, Ruby, Scala, Seed7, Smalltalk, Tcl, Visual Prolog and most .NET languages.
Excluding minor syntactic differences, there are only a couple of exception handling styles in use. In the most popular style, an exception is initiated by a special statement (throw or raise) with an exception object (e.g. with Java or Object Pascal) or a value of a special extendable enumerated type (e.g. with Ada or SML). The scope for exception handlers starts with a marker clause (try or the language's block starter such as begin) and ends in the start of the first handler clause (catch, except, rescue). Several handler clauses can follow, and each can specify which exception types it handles and what name it uses for the exception object. As a minor variation, some languages use a single handler clause, which deals with the class of the exception internally.
Also common is a related clause (finally or ensure) that is executed whether an exception occurred or not, typically to release resources acquired within the body of the exception-handling block. Notably, C++ does not provide this construct, recommending instead the Resource Acquisition Is Initialization (RAII) technique which frees resources using destructors. According to a 2008 paper by Westley Weimer and George Necula, the syntax of the try...finally blocks in Java is a contributing factor to software defects. When a method needs to handle the acquisition and release of 3–5 resources, programmers are apparently unwilling to nest enough blocks due to readability concerns, even when this would be a correct solution. It is possible to use a single try...finally block even when dealing with multiple resources, but that requires a correct use of sentinel values, which is another common source of bugs for this type of problem.
Python and Ruby also permit a clause (else) that is used in case no exception occurred before the end of the handler's scope was reached.
In its whole, exception handling code might look like this (in Java-like pseudocode):
try {
line = console.readLine();
if (line.length() == 0) {
throw new EmptyLineException("The line read from console was empty!");
}
console.printLine("Hello %s!" % line);
}
catch (EmptyLineException e) {
console.printLine("Hello!");
}
catch (Exception e) {
console.printLine("Error: " + e.message());
}
else {
console.printLine("The program ran successfully.");
}
finally {
console.printLine("The program is now terminating.");
}
C does not have try-catch exception handling, but uses return codes for error checking. The setjmp and longjmp standard library functions can be used to implement try-catch handling via macros.
Perl 5 uses die for throw and for try-catch. It has CPAN modules that offer try-catch semantics.
Termination and resumption semantics
When an exception is thrown, the program searches back through the stack of function calls until an exception handler is found. Some languages call for unwinding the stack as this search progresses. That is, if function , containing a handler for exception , calls function , which in turn calls function , and an exception occurs in , then functions and may be terminated, and in will handle . This is said to be termination semantics.
Alternately, the exception handling mechanisms may not unwind the stack on entry to an exception handler, giving the exception handler the option to restart the computation, resume or unwind. This allows the program to continue the computation at exactly the same place where the error occurred (for example when a previously missing file has become available) or to implement notifications, logging, queries and fluid variables on top of the exception handling mechanism (as done in Smalltalk). Allowing the computation to resume where it left off is termed resumption semantics.
There are theoretical and design arguments in favor of either decision. C++ standardization discussions in 1989–1991 resulted in a definitive decision to use termination semantics in C++. Bjarne Stroustrup cites a presentation by Jim Mitchell as a key data point:
Exception-handling languages with resumption include Common Lisp with its Condition System, PL/I, Dylan, R, and Smalltalk. However, the majority of newer programming languages follow C++ and use termination semantics.
Exception handling implementation
The implementation of exception handling in programming languages typically involves a fair amount of support from both a code generator and the runtime system accompanying a compiler. (It was the addition of exception handling to C++ that ended the useful lifetime of the original C++ compiler, Cfront.) Two schemes are most common. The first, , generates code that continually updates structures about the program state in terms of exception handling. Typically, this adds a new element to the stack frame layout that knows what handlers are available for the function or method associated with that frame; if an exception is thrown, a pointer in the layout directs the runtime to the appropriate handler code. This approach is compact in terms of space, but adds execution overhead on frame entry and exit. It was commonly used in many Ada implementations, for example, where complex generation and runtime support was already needed for many other language features. Microsoft's 32-bit Structured Exception Handling (SEH) uses this approach with a separate exception stack. Dynamic registration, being fairly straightforward to define, is amenable to proof of correctness.
The second scheme, and the one implemented in many production-quality C++ compilers and 64-bit Microsoft SEH, is a . This creates static tables at compile time and link time that relate ranges of the program counter to the program state with respect to exception handling. Then, if an exception is thrown, the runtime system looks up the current instruction location in the tables and determines what handlers are in play and what needs to be done. This approach minimizes executive overhead for the case where an exception is not thrown. This happens at the cost of some space, but this space can be allocated into read-only, special-purpose data sections that are not loaded or relocated until an exception is actually thrown. The location (in memory) of the code for handling an exception need not be located within (or even near) the region of memory where the rest of the function's code is stored. So if an exception is thrown then a performance hit – roughly comparable to a function call – may occur if the necessary exception handling code needs to be loaded/cached. However, this scheme has minimal performance cost if no exception is thrown. Since exceptions in C++ are supposed to be exceptional (i.e. uncommon/rare) events, the phrase "zero-cost exceptions" is sometimes used to describe exception handling in C++. Like runtime type identification (RTTI), exceptions might not adhere to C++'s zero-overhead principle as implementing exception handling at run-time requires a non-zero amount of memory for the lookup table. For this reason, exception handling (and RTTI) can be disabled in many C++ compilers, which may be useful for systems with very limited memory (such as embedded systems). This second approach is also superior in terms of achieving thread safety.
Other definitional and implementation schemes have been proposed as well. For languages that support metaprogramming, approaches that involve no overhead at all (beyond the already present support for reflection) have been advanced.
Exception handling based on design by contract
A different view of exceptions is based on the principles of design by contract and is supported in particular by the Eiffel language. The idea is to provide a more rigorous basis for exception handling by defining precisely what is "normal" and "abnormal" behavior. Specifically, the approach is based on two concepts:
Failure: the inability of an operation to fulfill its contract. For example, an addition may produce an arithmetic overflow (it does not fulfill its contract of computing a good approximation to the mathematical sum); or a routine may fail to meet its postcondition.
Exception: an abnormal event occurring during the execution of a routine (that routine is the "recipient" of the exception) during its execution. Such an abnormal event results from the failure of an operation called by the routine.
The "Safe Exception Handling principle" as introduced by Bertrand Meyer in Object-Oriented Software Construction then holds that there are only two meaningful ways a routine can react when an exception occurs:
Failure, or "organized panic": The routine fixes the object's state by re-establishing the invariant (this is the "organized" part), and then fails (panics), triggering an exception in its caller (so that the abnormal event is not ignored).
Retry: The routine tries the algorithm again, usually after changing some values so that the next attempt will have a better chance to succeed.
In particular, simply ignoring an exception is not permitted; a block must either be retried and successfully complete, or propagate the exception to its caller.
Here is an example expressed in Eiffel syntax. It assumes that a routine is normally the better way to send a message, but it may fail, triggering an exception; if so, the algorithm next uses , which will fail less often. If fails, the routine as a whole should fail, causing the caller to get an exception.
send (m: MESSAGE) is
-- Send m through fast link, if possible, otherwise through slow link.
local
tried_fast, tried_slow: BOOLEAN
do
if tried_fast then
tried_slow := True
send_slow (m)
else
tried_fast := True
send_fast (m)
end
rescue
if not tried_slow then
retry
end
end
The boolean local variables are initialized to False at the start. If fails, the body ( clause) will be executed again, causing execution of . If this execution of fails, the clause will execute to the end with no (no clause in the final ), causing the routine execution as a whole to fail.
This approach has the merit of defining clearly what "normal" and "abnormal" cases are: an abnormal case, causing an exception, is one in which the routine is unable to fulfill its contract. It defines a clear distribution of roles: the clause (normal body) is in charge of achieving, or attempting to achieve, the routine's contract; the clause is in charge of reestablishing the context and restarting the process, if this has a chance of succeeding, but not of performing any actual computation.
Although exceptions in Eiffel have a fairly clear philosophy, Kiniry (2006) criticizes their implementation because "Exceptions that are part of the language definition are represented by INTEGER values, developer-defined exceptions by STRING values. [...] Additionally, because they are basic values and not objects, they have no inherent semantics beyond that which is expressed in a helper routine which necessarily cannot be foolproof because of the representation overloading in effect (e.g., one cannot
differentiate two integers of the same value)."
Uncaught exceptions
Contemporary applications face many design challenges when considering exception handling strategies. Particularly in modern enterprise level applications, exceptions must often cross process boundaries and machine boundaries. Part of designing a solid exception handling strategy is recognizing when a process has failed to the point where it cannot be economically handled by the software portion of the process.
If an exception is thrown and not caught (operationally, an exception is thrown when there is no applicable handler specified), the uncaught exception is handled by the runtime; the routine that does this is called the . The most common default behavior is to terminate the program and print an error message to the console, usually including debug information such as a string representation of the exception and the stack trace. This is often avoided by having a top-level (application-level) handler (for example in an event loop) that catches exceptions before they reach the runtime.
Note that even though an uncaught exception may result in the program terminating abnormally (the program may not be correct if an exception is not caught, notably by not rolling back partially completed transactions, or not releasing resources), the process terminates normally (assuming the runtime works correctly), as the runtime (which is controlling execution of the program) can ensure orderly shutdown of the process.
In a multithreaded program, an uncaught exception in a thread may instead result in termination of just that thread, not the entire process (uncaught exceptions in the thread-level handler are caught by the top-level handler). This is particularly important for servers, where for example a servlet (running in its own thread) can be terminated without the server overall being affected.
This default uncaught exception handler may be overridden, either globally or per-thread, for example to provide alternative logging or end-user reporting of uncaught exceptions, or to restart threads that terminate due to an uncaught exception. For example, in Java this is done for a single thread via Thread.setUncaughtExceptionHandler and globally via Thread.setDefaultUncaughtExceptionHandler; in Python this is done by modifying sys.excepthook.
Checked exceptions
Java introduced the notion of checked exceptions, which are special classes of exceptions. The checked exceptions that a method may raise must be part of the method's signature. For instance, if a method might throw an , it must declare this fact explicitly in its method signature. Failure to do so raises a compile-time error. According to Hanspeter Mössenböck, checked exceptions are less convenient but more robust. Checked exceptions can, at compile time, reduce the incidence of unhandled exceptions surfacing at runtime in a given application.
Kiniry writes that "As any Java programmer knows, the volume of try catch code in a typical Java application is sometimes larger than the comparable code necessary for explicit formal parameter and return value checking in other languages that do not have checked exceptions. In fact, the general consensus among in-the-trenches Java programmers is that dealing with checked exceptions is nearly as unpleasant a task as writing documentation. Thus, many programmers report that they “resent” checked exceptions.". Martin Fowler has written "...on the whole I think that exceptions are good, but Java checked exceptions are more trouble than they are worth." As of 2006 no major programming language has followed Java in adding checked exceptions. For example, C# does not require or allow declaration of any exception specifications, with the following posted by Eric Gunnerson:
Anders Hejlsberg describes two concerns with checked exceptions:
Versioning: A method may be declared to throw exceptions X and Y. In a later version of the code, one cannot throw exception Z from the method, because it would make the new code incompatible with the earlier uses. Checked exceptions require the method's callers to either add Z to their throws clause or handle the exception. Alternately, Z may be misrepresented as an X or a Y.
Scalability: In a hierarchical design, each systems may have several subsystems. Each subsystem may throw several exceptions. Each parent system must deal with the exceptions of all subsystems below it, resulting in an exponential number of exceptions to be dealt with. Checked exceptions require all of these exceptions to be dealt with explicitly.
To work around these, Hejlsberg says programmers resort to circumventing the feature by using a declaration. Another circumvention is to use a handler. This is referred to as catch-all exception handling or Pokémon exception handling after the show's catchphrase "Gotta Catch ‘Em All!". The Java Tutorials discourage catch-all exception handling as it may catch exceptions "for which the handler was not intended". Still another discouraged circumvention is to make all exceptions subclass . An encouraged solution is to use a catch-all handler or throws clause but with a specific superclass of all potentially thrown exceptions rather than the general superclass . Another encouraged solution is to define and declare exception types that are suitable for the level of abstraction of the called method and map lower level exceptions to these types by using exception chaining.
Similar mechanisms
The roots of checked exceptions go back to the CLU programming language's notion of exception specification. A function could raise only exceptions listed in its type, but any leaking exceptions from called functions would automatically be turned into the sole runtime exception, , instead of resulting in compile-time error. Later, Modula-3 had a similar feature. These features don't include the compile time checking that is central in the concept of checked exceptions.
Early versions of the C++ programming language included an optional mechanism similar to checked exceptions, called exception specifications. By default any function could throw any exception, but this could be limited by a clause added to the function signature, that specified which exceptions the function may throw. Exception specifications were not enforced at compile-time. Violations resulted in the global function being called. An empty exception specification could be given, which indicated that the function will throw no exception. This was not made the default when exception handling was added to the language because it would have required too much modification of existing code, would have impeded interaction with code written in other languages, and would have tempted programmers into writing too many handlers at the local level. Explicit use of empty exception specifications could, however, allow C++ compilers to perform significant code and stack layout optimizations that are precluded when exception handling may take place in a function. Some analysts viewed the proper use of exception specifications in C++ as difficult to achieve. This use of exception specifications was included in C++98 and C++03, deprecated in the 2012 C++ language standard (C++11), and was removed from the language in C++17. A function that will not throw any exceptions can now be denoted by the keyword.
An uncaught exceptions analyzer exists for the OCaml programming language. The tool reports the set of raised exceptions as an extended type signature. But, unlike checked exceptions, the tool does not require any syntactic annotations and is external (i.e. it is possible to compile and run a program without having checked the exceptions).
Dynamic checking of exceptions
The point of exception handling routines is to ensure that the code can handle error conditions. In order to establish that exception handling routines are sufficiently robust, it is necessary to present the code with a wide spectrum of invalid or unexpected inputs, such as can be created via software fault injection and mutation testing (that is also sometimes referred to as fuzz testing). One of the most difficult types of software for which to write exception handling routines is protocol software, since a robust protocol implementation must be prepared to receive input that does not comply with the relevant specification(s).
In order to ensure that meaningful regression analysis can be conducted throughout a software development lifecycle process, any exception handling testing should be highly automated, and the test cases must be generated in a scientific, repeatable fashion. Several commercially available systems exist that perform such testing.
In runtime engine environments such as Java or .NET, there exist tools that attach to the runtime engine and every time that an exception of interest occurs, they record debugging information that existed in memory at the time the exception was thrown (call stack and heap values). These tools are called automated exception handling or error interception tools and provide 'root-cause' information for exceptions.
Asynchronous exceptions
Asynchronous exceptions are events raised by a separate thread or external process, such as pressing Ctrl-C to interrupt a program, receiving a signal, or sending a disruptive message such as "stop" or "suspend" from another thread of execution. Whereas synchronous exceptions happen at a specific throw statement, asynchronous exceptions can be raised at any time. It follows that asynchronous exception handling can't be optimized out by the compiler, as it cannot prove the absence of asynchronous exceptions. They are also difficult to program with correctly, as asynchronous exceptions must be blocked during cleanup operations to avoid resource leaks.
Programming languages typically avoid or restrict asynchronous exception handling, for example C++ forbids raising exceptions from signal handlers, and Java has deprecated the use of its ThreadDeath exception that was used to allow one thread to stop another one. Another feature is a semi-asynchronous mechanism that raises an asynchronous exception only during certain operations of the program. For example, Java's only affects the thread when the thread calls an operation that throws . The similar POSIX API has race conditions which make it impossible to use safely.
Condition systems
Common Lisp, R, Dylan and Smalltalk have a condition system (see Common Lisp Condition System) that encompasses the aforementioned exception handling systems. In those languages or environments the advent of a condition (a "generalisation of an error" according to Kent Pitman) implies a function call, and only late in the exception handler the decision to unwind the stack may be taken.
Conditions are a generalization of exceptions. When a condition arises, an appropriate condition handler is searched for and selected, in stack order, to handle the condition. Conditions that do not represent errors may safely go unhandled entirely; their only purpose may be to propagate hints or warnings toward the user.
Continuable exceptions
This is related to the so-called resumption model of exception handling, in which some exceptions are said to be continuable: it is permitted to return to the expression that signaled an exception, after having taken corrective action in the handler. The condition system is generalized thus: within the handler of a non-serious condition (a.k.a. continuable exception), it is possible to jump to predefined restart points (a.k.a. restarts) that lie between the signaling expression and the condition handler. Restarts are functions closed over some lexical environment, allowing the programmer to repair this environment before exiting the condition handler completely or unwinding the stack even partially.
An example is the ENDPAGE condition in PL/I; the ON unit might write page trailer lines and header lines for the next page, then fall through to resume execution of the interrupted code.
Restarts separate mechanism from policy
Condition handling moreover provides a separation of mechanism and policy. Restarts provide various possible mechanisms for recovering from error, but do not select which mechanism is appropriate in a given situation. That is the province of the condition handler, which (since it is located in higher-level code) has access to a broader view.
An example: Suppose there is a library function whose purpose is to parse a single syslog file entry. What should this function do if the entry is malformed? There is no one right answer, because the same library could be deployed in programs for many different purposes. In an interactive log-file browser, the right thing to do might be to return the entry unparsed, so the user can see it—but in an automated log-summarizing program, the right thing to do might be to supply null values for the unreadable fields, but abort with an error, if too many entries have been malformed.
That is to say, the question can only be answered in terms of the broader goals of the program, which are not known to the general-purpose library function. Nonetheless, exiting with an error message is only rarely the right answer. So instead of simply exiting with an error, the function may establish restarts offering various ways to continue—for instance, to skip the log entry, to supply default or null values for the unreadable fields, to ask the user for the missing values, or to unwind the stack and abort processing with an error message. The restarts offered constitute the mechanisms available for recovering from error; the selection of restart by the condition handler supplies the policy.
Criticism
Exception handling is often not handled correctly in software, especially when there are multiple sources of exceptions; data flow analysis of 5 million lines of Java code found over 1300 exception handling defects.
Citing multiple prior studies by others (1999–2004) and their own results, Weimer and Necula wrote that a significant problem with exceptions is that they "create hidden control-flow paths that are difficult for programmers to reason about". "While try-catch-finally is conceptually simple, it has the most complicated execution description in the language specification [Gosling et al. 1996] and requires four levels of nested “if”s in its official English description. In short, it contains a large number of corner cases that programmers often overlook."
Exceptions, as unstructured flow, increase the risk of resource leaks (such as escaping a section locked by a mutex, or one temporarily holding a file open) or inconsistent state. There are various techniques for resource management in the presence of exceptions, most commonly combining the dispose pattern with some form of unwind protection (like a finally clause), which automatically releases the resource when control exits a section of code.
Tony Hoare in 1980 described the Ada programming language as having "...a plethora of features and notational conventions, many of them unnecessary and some of them, like exception handling, even dangerous. [...] Do not allow this language in its present state to be used in applications where reliability is critical [...]. The next rocket to go astray as a result of a programming language error may not be an exploratory space rocket on a harmless trip to Venus: It may be a nuclear warhead exploding over one of our own cities."
The Go developers believe that the try-catch-finally idiom obfuscates control flow, and introduced the exception-like / mechanism. differs from in that it can only be called from within a code block in a function, so the handler can only do clean-up and change the function's return values, and cannot return control to an arbitrary point within the function. The block itself functions similarly to a clause.
See also
Automated exception handling
Continuation
Defensive programming
Exception safety
Option types and Result types, alternative ways of handling errors in functional programming without exceptions
Notes
References
Works cited
Control flow
Software anomalies | Exception handling (programming) | [
"Technology"
] | 6,227 | [
"Computer errors",
"Technological failures",
"Software anomalies"
] |
72,943,601 | https://en.wikipedia.org/wiki/Data%20centre%20industry%20in%20India | India has growing data centre industry. Data centres are used for national security, internet infrastructure, and economic output. As of 2024, India's data centre capacity is at 950 MW, which is expected to be 1800 MW by 2026. The data centre industry is valued at US$1.2 billion in 2021, a 216% growth from $385 million in 2014. The number of data centres in India is 138, as of March 2022. India ranks 13th globally in terms of highest number of data centres.
As of 2021, Indian data centres occupy over 8 million sq ft area. 60% of total data centres are in Mumbai, Chennai, Delhi, Bangalore and Hyderabad.
India's data centre capacity is projected to experience significant growth, doubling from 0.9 GW in 2023 to approximately 2 GW by 2026. This expansion is driven by the increasing digitization and data localization trends within the country. Despite generating 20% of the global data, India currently holds only a 3% share of global data centre capacity, highlighting substantial under-penetration in this sector. The estimated capital expenditure required for this capacity addition is around Rs 50,000 crore over the next three years. The cost of setting up data centres has also risen, with the average cost per MW increasing from Rs 40-45 crore to Rs 60-70 crore. The absorption levels in the industry have improved from 82% in 2019 to 93% in 2023, with revenue for industry players growing at a CAGR of nearly 25% from FY17 to FY23. CareEdge Ratings projects a 32% CAGR growth in revenue during FY24–26, with stable EBITDA margins expected over the next three years. The industry is also anticipated to see the entry of new players, which will help diversify the market share currently dominated by the top five players. The shift towards edge data centres is expected to meet the growing demand from tier II and tier III cities, ensuring lower latency and better service delivery.
Industry statistics
Data centres in India are used for information technology, submarine cable connectivity economic output, personal data protection legislation and investment incentives etc. As per JLL, Indian data centre industry is expected to add more 681 MW capacity by the end of 2024 leading to a doubling of existing capacity to 1,318 MW with 7.8 million sq ft of real estate space. Mumbai is expected to account for 57 percent of the new supply followed by Chennai at 25 percent. The 5g rollout also has enhanced the need of data centre capacity since it will increase data download speeds in India 10 times. Also Over-the-top media services in India, video streaming, online gaming, augmented reality and digital commerce are major factors of the developing industry.
Major data centre hubs
Mumbai
Mumbai holds the largest data centre market with a 44% alone. The total capacity is 289 MW, with 3.6 million sq ft in its functional area. Big data centre giants like Sify, STT, CtrlS, Yotta, Nxtra Data, Web Werks,
NTT etc. In 2020, REIT Equinix signed a deal to invest $161 million to feciliate a 19 MW local operations of GPX. Yotta Data Services Private Limited, CapitaLand, AdaniConneX venture had their major data centre projects in Mumbai.
Google has planned to set up an 8-storey 381,000 sq ft data centre in Navi Mumbai by 2025 with an investment of ₹1144 crore in first 10 years. Also Microsoft has plans to build a data centre in Mumbai. CtrlS Datacenters Ltd, which had eight data centres (as of 2023) aims to have about 25 data centres by 2024–25 in India. It plans to expand 5 million sq ft after its existing 1.2 million sw ft, in which a 2 million sq ft hyperscale data centre is under construction in Navi Mumbai.
Mumbai has emerged as the third biggest data centre market in the Asia-Pacific region, with a total capacity at 2,337 MW and breaching the 2GW mark, in 2023, behind Shanghai and Tokyo.
Chennai
Chennai has a major presence of data centre since it has the market with the second-highest number of undersea cables after Mumbai. Total capacity is 57 MW with 8% market share and a total of 0.92 million sq ft. Chennai is projected to overtake other markets to the second-largest up to 2030. Sify, Yotta, CtrlS, Princeton Digital, CapitaLand, STT, and NxtGen have more than one campuses adding to local capacity.
The Adani enterprises has signed an MoU with the Tamil Nadu government to set up a data centre in Chennai, with an investment of Rs 2,500 crore.
Hyderabad
Due to its IT presence, Hyderabad consists the data centre industry with 6% market share, capacity of 38 MW and 0.71 million sq ft area. STT, CapitaLand, Sify, and CtrlS are key players in the city.
Bangalore
Bangalore, known as the Silicon Valley of India, has a major data centre presence due to its large IT infrastructure. As of 2020 Bangalore has a total capacity of 162 MW having 1.74 Million sq ft used for data centre. It possesses a 25% of the market share. ESDS, Sungard, Sify, Whitefield Nxtra Data, CapitaLand, Evoque, STT, NTT etc. have their data centres here.
Noida (Delhi-NCR)
Noida, which falls under the Delhi-NCR has a significant data centre industry. It is the only data centre hub in North India. Delhi has a capacity of 72 MW and a total of 1.05 million sq ft with 11% market share.
Google has acquired a 464,000 sq ft facility at Adani Centre in Noida in 2022.
Pune
Having IT industry in its main economy, Pune consists data centres with total capacity of 32 MW and 0.44 million sq ft with a 5% market share. National companies like Nxtra, STT, Web Werks Microsoft Azure have set up their campuses in Pune.
Kolkata
Kolkata is the only data centre hub in the East India region with total capacity of 5 MW and 0.07 million sq ft with a market share of 1%. Major players are Sify and STT. Sify has a data centre of 2 MW with 350 rack space.
Multiple data centre projects are under construction. As of 2021, Kolkata comes second in terms of land earmarked for data centres with 195 acres in its forey. Reliance Jio has acquired a 40-acre plot for a data centre. The Adani Enterprise has taken a 51.8 acre plot in the Silicon Valley Hub, New Town to build a hyperscale data centre with ₹10,000 crore investment.
Also Bharti Airtel Nxtra Data, has acquired plot to build a hyper-scale data centre of 25 MW (150,000 sq ft) in Kolkata with an investment of ₹600 crore, which is under construction as of 2022.
Hiranandani Group is also planning six data centres at Hind Motor, Uttarpara, West Bengal. The group acquired 100-acre plot at Uttarpara, Hooghly, to set up six data centres (total 250 MW) with an investment of 8,500 crore.
Future growth
In 2024, India's data centre industry is experiencing rapid growth, driven by increased digitalisation, rising internet penetration, and the government's push towards digital initiatives. The industry is expected to reach a market size of $5 billion by the end of 2024, reflecting a compound annual growth rate (CAGR) of around 25% over the past few years. Significant investments from both domestic and international players are enhancing the country's data infrastructure to meet the growing demand for storage and processing capabilities. Major global tech companies like Amazon Web Services, Microsoft, and Google are collectively investing over $2 billion in expanding their data centre footprints in India, contributing to the industry's rapid expansion.
The Indian government's role in fostering this growth is pivotal. By introducing favourable policies and incentives, such as the Digital India program and data localisation mandates, the government is creating a conducive environment for investment. The data localisation policies alone are projected to drive the construction of over 100 new data centres by 2025. This is further supported by the proliferation of smartphones, e-commerce, and digital services, which has led to an exponential increase in data generation, with the total data consumption in India expected to surpass 25 exabytes per month by 2025. Businesses across various sectors are adopting cloud services, AI, and big data analytics, driving the need for robust data centre infrastructure.
Looking ahead, the data centre industry in India is expected to continue its rapid expansion. The market is projected to grow to $8 billion by 2026. Companies will likely invest heavily in modernizing existing facilities and constructing new ones to keep pace with technological advancements and growing demand. Additionally, there will be a stronger emphasis on sustainability, with data centres increasingly adopting green technologies and practices to minimize their environmental impact. This focus on sustainable development will be crucial as the industry scales up to meet the future digital needs of the country, with renewable energy sources expected to power at least 50% of data centres by 2030.
See also
Information technology in India
References
Data centers
Internet in India
Industry in India | Data centre industry in India | [
"Technology"
] | 1,935 | [
"Data centers",
"Computers"
] |
72,945,504 | https://en.wikipedia.org/wiki/Bou%C3%A9%E2%80%93Dupuis%20formula | In stochastic calculus, the Boué–Dupuis formula is variational representation for Wiener functionals. The representation has application in finding large deviation asymptotics.
The theorem was proven in 1998 by Michelle Boué and Paul Dupuis. In 2000 the result was generalized to infinite-dimensional Brownian motions and in 2009 extended to abstract Wiener spaces.
Boué–Dupuis formula
Let be the classical Wiener space and be a -dimensional standard Brownian motion. Then for all bounded and measurable functions
we have the following variational representation
where:
The expectation is with respect to the probability space of .
The infimum runs over all processes which are progressively measurable with respect to the augmented filtration generated by
denotes the -dimensional Euclidean norm.
References
Stochastic calculus
Wiener process
Probability theorems
Calculus of variations | Boué–Dupuis formula | [
"Mathematics"
] | 171 | [
"Theorems in probability theory",
"Mathematical theorems",
"Mathematical problems"
] |
72,946,978 | https://en.wikipedia.org/wiki/HD%20176664 | HD 176664, also known as HR 7190 or rarely 43 G. Telescopii, is a solitary star located in the southern constellation Telescopium. It is faintly visible to the naked eye as an orange-hued star with an apparent magnitude of 5.93. The object is located relatively close at a distance of 292 light years based on Gaia DR3 parallax measurements but is rapidly approaching the Solar System with a heliocentric radial velocity of . At its current distance HD 176664's brightness is diminished by two-tenths of a magnitude due to interstellar dust. It has an absolute magnitude of +0.94.
HD 176664 has a stellar classification of K0/1 III, indicating that it is an evolved K-type star with a spectrum intermediate of a K0 and K1 giant star. It has a comparable mass to the Sun but it has expanded to 12.4 times its girth. It radiates 49.9 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of . HD 176664 is metal enriched ([Fe/H] = +0.25) and spins too slowly to be measured accurately. A 1993 paper by Olin J. Eggen lists HD 176664 as a member of the Milky Way's old disk population.
The star has two optical companions designated CD −51°11893B and CD −51°11893C. B is a distant 13th magnitude star located 19.4" away along a position angle of 9° while C is a 12th magnitude star located 27.5" away along a position angle of 29°.
References
K-type giants
Multiple stars
Telescopium
CD-51 11893
176664
093624
7190
Telescopii, 43 | HD 176664 | [
"Astronomy"
] | 378 | [
"Telescopium",
"Multiple stars",
"Sky regions",
"Constellations"
] |
72,948,513 | https://en.wikipedia.org/wiki/Technetium%20%2899mTc%29%20pentetic%20acid | {{DISPLAYTITLE:Technetium (99mTc) pentetic acid}}
Technetium (99mTc) pentetic acid, sold under the brand name Draximage DTPA among others, is a radiopharmaceutical medication used in nuclear medicine to image the brain, kidneys, or lungs. It is given by intravenous injection or via aerosol spray. It consists of technetium-99m bound to the conjugate base of pentetic acid, with sodium as an additional cation.
Medical uses
Technetium (99mTc) pentetic acid is indicated for use in the diagnosis of the brain, kidneys, or lungs.
References
Radiopharmaceuticals | Technetium (99mTc) pentetic acid | [
"Chemistry"
] | 156 | [
"Pharmacology",
"Medicinal radiochemistry",
"Medicinal chemistry stubs",
"Chemicals in medicine",
"Radiopharmaceuticals",
"Pharmacology stubs"
] |
72,949,465 | https://en.wikipedia.org/wiki/Ekiben%20%28sexual%20act%29 | is a sex position that consists of a person being carried by their partner while having sex with them.
Etymology
The act itself is named after the box that is filled with food that is sold by vendors walking around train stations or sporting events, ekiben. The term was first popularized by Japanese male actor, Chocoball Mukai.
Practice
The act usually involves a male partner lifting his female partner face to face with his penis inserted inside her vagina, and having sex while standing. The term can also apply when then act is done sitting down or when the lifted partner is held against a wall.
Other forms are known as or reverse ekiben, the same act only with the person being penetrated facing in the opposite direction.
See also
Bukkake
Gokkun
Mating press
Pornography in Japan
References
External links
Japanese sex terms
Pornography terminology
Sexual acts
Sexuality in Japan | Ekiben (sexual act) | [
"Biology"
] | 172 | [
"Behavior",
"Sexual acts",
"Sexuality stubs",
"Sexuality",
"Mating"
] |
72,949,511 | https://en.wikipedia.org/wiki/C.S.%20Unnikrishnan | C. S. Unnikrishnan (born 25 July 1962) is an Indian physicist and professor known for his contributions in multiple areas of experimental and theoretical physics. He has been a professor at the Tata Institute of Fundamental Research Mumbai and is currently a professor in the School of Quantum Technology at the Defence Institute of Advanced Technology in Pune. He has made significant contributions in foundational issues in gravity and quantum physics and has published over 250 research papers and articles. Unnikrishnan is also a key member of the LIGO-India project and a member of the global LIGO Scientific Collaboration
Education
Unnikrishnan received his M.Sc. degree from Indian Institute of Technology, Madras and his Ph.D. from the Tata Institute of Fundamental Research, University of Mumbai. He has also been a visiting researcher at the Kastler-Brossel Laboratory of the Ecole Normale Supérieure in Paris and at the University of Paris 13.
Research contributions
Unnikrishnan is a renowned researcher in the field of foundational issues in gravity and quantum physics, including quantum optics. His expertise lies in experimental physics, and he has been instrumental in setting up the laser-cooling laboratory at TIFR, Mumbai. He is well-versed in the use of torsion balances, interferometers, laser cooled atoms, and Bose-Einstein Condensates for his experiments.
Unnikrishnan's major theoretical contributions include the Theory of Cosmic Relativity and Universal Action Mechanics. These theories have provided new insights into our understanding of the interplay between gravity and quantum mechanics, and have opened up new avenues for further research. Cosmic Relativity, replaces current theories of dynamics and relativity and argues that all relativistic phenomena and laws of dynamics are controlled by the gravitational potentials of matter and energy in the universe. It provides evidence and solutions to several major issues in fundamental physics.
The discovery of the quantization of the Hall effect, where the movement of electrons is restricted to a 2-D plane, was characterized by quantized plateaus in the Hall resistance and has a simple theory for the integer quantum Hall effect, but there is still no proper understanding of the more spectacular fractional quantum Hall effect. The Cosmic Relativity theory offers a comprehensive understanding of both integer and fractional effects by modifying the quantum degeneracy due to cosmic gravitomagnetic interaction.
Professional accomplishments
Awards
Breakthrough Prize in Physics (2016)
Gruber Prize in Cosmology (2016)
Unnikrishnan is a key member and proposer-scientist of the LIGO-India project and has been a member of the LIGO Scientific Collaboration (LSC). He has made a significant impact in the field of gravitational waves as he shared the Breakthrough Prize in Physics and the Gruber Prize in Cosmology with the LSC in 2016 for their groundbreaking discovery.
He has held academic positions at the Tata Institute of Fundamental Research (TIFR) Mumbai, India, School of Quantum Technology at the Defence Institute of Advanced Technology (DIAT) Pune, India and Indian Institute of Astrophysics (IIA), Bangalore, India.
Unnikrishnan has published over 250 research papers and articles, and is also the author of two major works: his first monograph "Gravity's Time" and a major treatise "New Relativity in the Gravitational Universe". The treatise, which presents a new and innovative perspective on the foundational basis of relativity, has had a major impact in the field. The latter book calls for a change in the foundational basis of relativity and provides a solution to outstanding questions and puzzles about dynamics and relativity.
Books authored
Gravity's Time
New Relativity in the Gravitational Universe
References
Indian scientists
Indian physicists
Tata Institute of Fundamental Research alumni
Academic staff of Tata Institute of Fundamental Research
Relativity theorists
Defence Research and Development Organisation
Indian quantum physicists
21st-century Indian scientists
1962 births
Living people | C.S. Unnikrishnan | [
"Physics"
] | 778 | [
"Relativity theorists",
"Theory of relativity"
] |
72,949,749 | https://en.wikipedia.org/wiki/Alexandrov%27s%20soap%20bubble%20theorem | Alexandrov's soap bubble theorem is a mathematical theorem from geometric analysis that characterizes a sphere through the mean curvature. The theorem was proven in 1958 by Alexander Danilovich Alexandrov. In his proof he introduced the method of moving planes, which was used after by many mathematicians successfully in geometric analysis.
Soap bubble theorem
Let be a bounded connected domain with a boundary that is of class with a constant mean curvature, then is a sphere.
Literature
References
Differential geometry | Alexandrov's soap bubble theorem | [
"Mathematics"
] | 96 | [
"Theorems in differential geometry",
"Theorems in geometry"
] |
72,952,138 | https://en.wikipedia.org/wiki/Hunchback%20%28gene%29 | Hunchback is a maternal effect and zygotic gene expressed in the embryos of the fruit fly Drosophila melanogaster. In maternal effect genes, the RNA or protein from the mother’s gene is deposited into the oocyte or embryo before the embryo can express its own zygotic genes.
Hunchback is a morphogen, meaning the concentration gradient of Hunchback at a specific region determines the segment or body part it develops into. This is possible because Hunchback is a transcription factor protein that binds to genes’ regulatory regions, changing RNA expression levels.
Hunchback expression pathway
Maternal Hunchback RNA enters the embryo at the syncytial blastoderm stage, where the entire embryo has undergone many nuclear divisions but has one communal cytoplasm, allowing for RNA to disperse freely throughout the embryo. This allows the maternal effect genes Hunchback, Bicoid, Nanos, and Caudal to regulate zygotic genes to create different identities for different regions of the body.
The first step is establishing the anterior and posterior regions, which later give rise to the respective head and abdomen. In the syncytial blastoderm, Bicoid and Nanos RNA bind to protein ropes involved in cellular locomotion and intracellular transport called microtubules that ferry the RNA to the anterior and posterior regions, respectively. Hunchback does not bind to microtubules and therefore diffuses uniformly throughout the embryo. However, Nanos represses the translation of the Hunchback protein. Since Nanos is ferried to the posterior pole, maternal Hunchback is expressed predominantly in the anterior pole.
Hunchback is also expressed zygotically in the farmost anterior and posterior poles of the syncytial blastoderm. Anterior zygotic Hunchback expression is controlled by enhancers, regions of DNA that increase gene expression when transcription factors are bound. One enhancer is close to Hunchback, and a recently discovered enhancer is farther away. When Bicoid binds to these enhancers, the expression of Hunchback increases proportionally to the Bicoid concentration in the anterior pole. A separate regulatory region downstream of the Hunchback enhancers governs the posterior expression of zygotic Hunchback. Here, Hunchback expression is proportional to the concentration of Tailless and Huckebein proteins available to bind to the regulatory region.
Effects of Hunchback expression
As a bifunctional transcription factor, Hunchback both activates and represses its target segmentation genes, and in doing so, regulates the anterior and posterior embryonic segmentation in the Drosophila embryo. For example, anterior Hunchback expression is known to establish the region that later develops into the thoracic and jaw- and mouth-related segments, and posterior Hunchback expression for the development of abdominal segments.
Hunchback’s morphogenetic gradient regulates the expression of other gap genes, Krüppel and Knirps, wherein maternal Hunchback expression defines the anterior Knirps and posterior Krüppel borders, while zygotic Hunchback expression establishes the anterior Knirps border.
Hunchback also establishes the expression pattern of pair-rule genes, such as even-skipped, expressed later in development to define distinct segments along the anterior-posterior axis. Pair-rule genes then encode transcription factors that regulate segment polarity genes: the final, most specified group of proteins that coordinate segmentation.
Clinical significance
The Hunchback gene has a known human ortholog that evolved from a common ancestor, the Pegasus gene (Ikzf5) of the Ikaros family zinc finger group. Ikaros family genes encode transcription factors that have implications in thrombocytopenia, a blood clotting deficiency, acute myeloid leukemia, a blood and bone marrow cancer, and are involved in mammalian retinal and immune system development. Ikaros family genes have also been implicated as an indicator for chronic graft-versus-host disease, a condition where immune cells attack transplanted tissue.
See also
Drosophila embryogenesis
Drosophila melanogaster
Maternal effect
Gap gene
References
Drosophila melanogaster genes
Developmental genes and proteins
Morphogens | Hunchback (gene) | [
"Biology"
] | 883 | [
"Morphogens",
"Induced stem cells",
"Developmental genes and proteins"
] |
72,952,330 | https://en.wikipedia.org/wiki/BAF%20agar | BAF agar or biotin-aneurin-folic acid agar is a type of agar growth medium containing peptones. It is used to grow cultures of mycorrhizal fungi. It was first described by in Nutritional requirements of Lactarius species and cultural characters in relation to taxonomy in 1981. The acidic pH (5.8-6.3) of BAF agar inhibits bacterial growth.
Typical composition
BAF agar typically contains:
30.0 g/L glucose
2.0 g/L peptone
0.2 g/L yeast extract
0.5 g/L KH2PO4
0.5 g/L MgSO4.7 H2O
10.0 mg/L FeCl3.6 H2O
1.0 mg/L ZnSO4.7 H2O
5.0 mg/L MnSO4
100.0 mg/L CaCl2.2 H2O
50.0 μg/L thiamine HCl
1.0 μg/L biotin
100.0 μg/L folic acid
50.0 μg/L inositol
15 g/L agar
References
Microbiological media | BAF agar | [
"Biology"
] | 252 | [
"Microbiological media",
"Microbiology equipment"
] |
72,952,360 | https://en.wikipedia.org/wiki/Huainan%20biota | The Huainan biota is a collection of macroscopic skeletal organisms discovered in the early 1980s by Wang and Sun Weiguo in the Precambrian deposits of China (Huainan City, Anhui Province) with an age of 840-740 Ma (Tonian). A similar biota was also found by M. B. Gnilovskaya in Russia, on the Timan Ridge; its age is about 1 billion years.
So far, it has been poorly studied. It is only known that its constituent organisms (Protoarenicola, Pararenicola, Sinosabellidites) reached several centimeters in size (which is significantly inferior to the Ediacaran ones) and, apparently, had the shape of segmented tubes, often goblet-shaped, with extensions at the end. Assumptions have been made about both the animal (worm-like) and algal nature of these organisms.
Huainan biota do not contain jellyfish-like "discs" (as does the Ediacaran biota), nor any forms close to sponges which are generally, although not universally, considered the most primitive of modern animal groups. Apparently, the Huainan biota cannot be considered ancestral either to the Ediacaran, or even more so to the modern (Phanerozoic) biota.
See also
Otavia
References
Further literature
Sun Weiguo, Wang Guixiang, Zhou Benhe. Macroscopic worm-like body fossils from the Upper Precambrian (900—700 Ma), Huainan district, Anhui, China and their stratigraphic and evolutionary significance // Precambrian Research. — 1986. — Vol. 31, No. 4. — P. 377–403. — doi:10.1016/0301-9268(86)90041-0.
Leiming Yin, Weiguo Sun. Microbiota from the Neoproterozoic Liulaobei Formation in the Huainan region, northern Anhui, China. // Precambrian Research. - Volume 65, Issues 1–4, January 1994, Pages 95–114.
Proterozoic animals
Neoproterozoic
Proterozoic Eonothem of Asia
Ediacaran Asia
Fossiliferous stratigraphic units of Asia
Paleontology in Anhui
Geography of Anhui
Tonian life
Precambrian paleobiotas | Huainan biota | [
"Biology"
] | 501 | [
"Precambrian paleobiotas",
"Prehistoric biotas"
] |
72,952,480 | https://en.wikipedia.org/wiki/MMN%20medium | MMN medium or Modified Melin-Norkrans medium is a type of agar growth medium, used to grow cultures of mycorrhizal fungi, such as Boletus edulis and Tricholoma matsutake. It was first described by DH. Marx in The influence of ectotrophic mycorrhizal fungi on the resistance of pine roots to pathogenic infections. I. Antagonism of mycorrhizal fungi to root pathogenic fungi and soil bacteria in 1969. The acidic pH (5.6) of MMN agar inhibits bacterial growth.
Typical composition
MMN agar typically contains:
10 g/L glucose
3 g/L malt extract
0.25 g/L (NH4)2HPO4
0.025 g/L NaCl
0.5 g/L KH2PO4
0.05 g/L CaCl2
0.15 g/L MgSO4.7 H2O
0.012g/L FeCl3. 6 H2O
0.003 g/L thiamine
15 g/L agar
References
Microbiological media | MMN medium | [
"Biology"
] | 240 | [
"Microbiological media",
"Microbiology equipment"
] |
72,952,686 | https://en.wikipedia.org/wiki/N%C3%B8dvarsel | Nødvarsel (English: Emergency Alert) is a Cell Broadcast alarm system in use by the Norwegian government to quickly alert and inform citizens of hazardous or crisis situations. Using this system, authorities can send messages to users of mobile phones in specific areas by using specific cell towers to alert phones within their reach.
The system was launched on 10 January 2023 and is a common effort between the Police Service, the Directorate for Civil Protection and the Civil Defence in cooperation with the telecommunications companies that run the mobile networks of Norway; Telenor, Telia Norge and Ice.
It is implemented based upon a European Union directive requiring member states (Norway is a member state in the EEA) to have a digital as well as physical public warning system. This directive is commonly known as EU-Alert.
References
Emergency population warning systems | Nødvarsel | [
"Technology"
] | 168 | [
"Warning systems",
"Emergency population warning systems"
] |
72,952,871 | https://en.wikipedia.org/wiki/Hope%20Michelsen | Hope A. Michelsen is an American physical chemist and combustion scientist whose research involves the byproducts of combustion including soot, black carbon, greenhouse gases, the contribution of these substances to global warming, and the use of laser-induced incandescence to measure combustion products. She is an associate professor of mechanical engineering at the University of Colorado Boulder, in the Paul M. Rady Department of Mechanical Engineering.
Education and career
Michelsen was an undergraduate at Dartmouth College. Initially majoring in English, she became interested in environmental science before graduating in 1984 with high honors in chemistry; she also earned the college's Chandler T. White 1916 Research Prize. She went to Stanford University for graduate study in chemistry, also working as a student researcher at the IBM Almaden Research Center, and supported in part by the Nellie Yeoh Whetten Award of the American Vacuum Society. She completed her Ph.D. in 1993. Her doctorate involved surface chemistry in electronics manufacturing, but looking for a change of pace, she switched her research interests afterwards to atmospheric chemistry.
After postdoctoral research at Harvard University, Michelsen became a staff scientist for Atmospheric and Environmental Research, Inc. in 1997, and a member of the technical staff in the Sandia National Laboratories Combustion Research Facility in 1999. She returned to academia in 2019, as an associate professor of mechanical engineering at the University of Colorado Boulder. In 2020 she added an affiliation with the university's program in environmental engineering.
Recognition
Michelson was elected to the Alameda County (California) Women's Hall of Fame in 2013, the first woman from Sandia National Laboratories to be so honored.
She was named a Fellow of Optica (formerly the Optical Society of America) in 2017, "for pioneering contributions to the fundamental understanding of laser-radiation interactions with soot particles through laser-induced incandescence, absorption and scattering, and using laser-induced incandescence to assess environmental impacts of carbonaceous particles". She was elected as a Fellow of the American Physical Society (APS) in 2012, after a nomination from the APS Division of Chemical Physics, "for groundbreaking research in the chemical physics of combustion particulate formation and transformations, and for innovative and rigorous description of particle-radiation interactions".
References
External links
Home page
The Michelsen Lab for Particulate Chemistry and Diagnostics
Year of birth missing (living people)
Living people
American women chemists
American physical chemists
Women physical chemists
Dartmouth College alumni
Stanford University alumni
Sandia National Laboratories people
University of Colorado Boulder faculty
Fellows of Optica (society)
Fellows of the American Physical Society | Hope Michelsen | [
"Chemistry"
] | 526 | [
"Women physical chemists",
"Physical chemists"
] |
72,953,248 | https://en.wikipedia.org/wiki/Meritxell%20Huch | Meritxell Huch (Barcelona, 1978) is a stem cell biologist and director at the Max Planck Institute of Molecular Cell Biology and Genetics. Her research considers tissue regeneration and the development of tissue-specific disease models for human organs. She was awarded a European Research Council Consolidator Grant in 2023.
Early life and education
After college Huch decided she wanted to work in science because of a desire to understand how aspirin works. Huch was an undergraduate student at the University of Barcelona, where she studied pharmaceutical sciences. She remained there for her graduate studies, earning a Master in 2003 and doctorate in 2007. She completed her PhD research in the Centre for Genomic Regulation, where she worked alongside Cristina Fillat. After completing her doctoral research she spent a year as a postdoctoral fellow before moring to the Hubrecht Institute on a Marie Curie Fellowship. In Utrecht she worked in the laboratory of Hans Clevers, where she isolated the stem cells responsible for the turnover of the adult stomach.
Research and career
Huch was appointed a Sir Henry Dale Research Fellow at the Gurdon Institute at the University of Cambridge. She held a joint position with The Wellcome Trust and the Department of Physiology. After five years in Cambridge, Huch joined the Max Planck Institute of Molecular Cell Biology and Genetics as one of the first members of the Lise Meitner Excellence Program. She was appointed to the board of directors in 2022.
Inflammation and tissue damage are associated with chronic liver disease and cancer. Her group have extensively developed human organoid models to study the molecular basis of adult tissue regeneration. Having identified stem cells responsible for the rapid turnover of the adult stomach, Huch showed that they could be maintained in culture. Next she moved on to liver cells, demonstrating the replicative potential of progenitor cells during regeneration and showing they are promising candidates for future therapeutic interventions in liver diseases. Her research has the potential to reduce the use of animals in scientific research.
Select publication
Awards and honours
2016 The Hamdan Award for Medical Research Excellence Hamdan Awards
2017 The Women in Cell Biology Early Career Medal
2018 Dame Sheila Sherlock Prize
2018 Elected EMBO Young Investigator
2019 The BINDER Innovation Prize
2022 German Stem Cell Network Hilde Mangold Award
2023 European Research Council Consolidator Grant
2024 Otto Bayer Award
References
Scientists from Barcelona
1978 births
Stem cell researchers
Biologists from Catalonia
Women biologists
Spanish medical researchers
Women medical researchers
21st-century Spanish biologists
21st-century Spanish women scientists
University of Barcelona alumni
Living people
Max Planck Institute directors | Meritxell Huch | [
"Biology"
] | 510 | [
"Stem cell researchers",
"Stem cell research"
] |
72,953,611 | https://en.wikipedia.org/wiki/Vinyl%20formate | Vinyl formate is an organic compound with the formula . It is the ester formally derived from formic acid and vinyl alcohol. Although rare commercially, it occurs naturally. It can be prepared by transvinylation, say by treating vinyl versatate with formic acid in the presence of a mercury(II) catalyst..
References
Monomers
Vinyl esters
Formates | Vinyl formate | [
"Chemistry",
"Materials_science"
] | 76 | [
"Monomers",
"Polymer chemistry"
] |
72,955,496 | https://en.wikipedia.org/wiki/39%20Ceti | 39 Ceti, also known as AY Ceti, is a star about 244 light years from Earth in the constellation Cetus. It is a 5th magnitude star, making it faintly visible to the naked eye of an observer far from city lights. AY Ceti is an RS Canum Venaticorum variable (RS CVn) star, varying in brightness from magnitude 5.35 to 5.58 over a period of about 77 days.
In 1962, Alan Cousins discovered that 39 Ceti is a variable star, varying by just 0.12 magnitudes during the five nights that he observed it. In 1976 it was given the variable star designation AY Ceti. In 1983, Joel Eaton et al. examined photoelectric photometry data for the star spanning more than a decade, and determined that the brightness varied periodically by 0.18 magnitudes every days. They stated that 39 Ceti's variability and spectral features lead them to believe it is an RS CVn star. Long term monitoring by Ennio Poretti et al. showed that the amplitude of the brightness oscillations is not constant, and there are secular drifts in the average brightness over timescales much longer than the phototmetric period.
In 1982, Theodore Simon et al. announced that IUE spectra revealed that 39 Ceti is a spectroscopic binary, with a hot white dwarf (component B) companion orbiting a cooler star (component A). They also announced the detection of radio wavelength flare events. In 1985 follow-up publication, these authors derived an orbital period of days, differing by more than 20 days from the photometric period, making 39 Ceti one of the few (just two known at that time) RS CVn systems for which the orbital and photometric periods are grossly different.
39 Ceti A is believed to be a star on its first ascent up the red-giant branch, close to the bottom of the red giant branch where first dredge-up occurs. It is thought to be undergoing the dredge-up now, but with convection not yet reaching the core of the star.
Notes
1.These orbital elements were derived assuming a circular orbit. An earlier derivation found non-zero eccentricity of ~0.1.
References
Cetus
005951
007672
Ceti, AY
0373
RS Canum Venaticorum variables
White dwarfs
G-type giants
Emission-line stars | 39 Ceti | [
"Astronomy"
] | 497 | [
"Cetus",
"Constellations"
] |
72,956,855 | https://en.wikipedia.org/wiki/The%20Journal%20of%20Environmental%20Education | The Journal of Environmental Education is a bimonthly peer-reviewed academic journal focusing on environmental and sustainability education. It covers formal, non-formal, and informal education at all levels: early childhood, primary, secondary, and tertiary education. It is published by Routledge and the editor-in-chief is Alberto "Tico" Arenas (University of Arizona).
History
The journal was established in 1969 by Clarence "Clay" Schoenfeld (University of Wisconsin–Madison) as Environmental Education obtaining its current title in 1971.
Editors-in-chief
Abstracting and indexing
The journal is abstracted and indexed in:
According to the Journal Citation Reports, the journal has a 2022 impact factor of 3.1.
References
External links
Environmental science journals
Education journals
Routledge academic journals
Academic journals established in 1969
Bimonthly journals
English-language journals | The Journal of Environmental Education | [
"Environmental_science"
] | 171 | [
"Environmental science journals"
] |
72,958,957 | https://en.wikipedia.org/wiki/Cliquish%20function | In mathematics, the notion of a cliquish function is similar to, but weaker than, the notion of a continuous function and quasi-continuous function. All (quasi-)continuous functions are cliquish but the converse is not true in general.
Definition
Let be a topological space. A real-valued function is cliquish at a point if for any and any open neighborhood of there is a non-empty open set such that
Note that in the above definition, it is not necessary that .
Properties
If is (quasi-)continuous then is cliquish.
If and are quasi-continuous, then is cliquish.
If is cliquish then is the sum of two quasi-continuous functions .
Example
Consider the function defined by whenever and whenever . Clearly f is continuous everywhere except at x=0, thus cliquish everywhere except (at most) at x=0. At x=0, take any open neighborhood U of x. Then there exists an open set such that . Clearly this yields thus f is cliquish.
In contrast, the function defined by whenever is a rational number and whenever is an irrational number is nowhere cliquish, since every nonempty open set contains some with .
References
Calculus
Theory of continuous functions | Cliquish function | [
"Mathematics"
] | 264 | [
"Theory of continuous functions",
"Topology",
"Calculus"
] |
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