text large_stringlengths 148 17k | id large_stringlengths 47 47 | score float64 2.69 5.31 | tokens int64 36 7.79k | format large_stringclasses 13
values | topic large_stringclasses 2
values | fr_ease float64 20 157 |
|---|---|---|---|---|---|---|
Share this page:
MathGraph32 is a great free tool for exploring 2D and 3D math concepts.
Read the rest of this entry »
Posted in Computers & Internet, Learning, Mathematics | 4 Comments »
The 17-year cicada is due to emerge in north-eastern parts of USA in Spring 2013.
Posted in Environment, Mathematics | No Comments »... | <urn:uuid:4b60903d-3e14-4654-8568-ee6096f15495> | 3.1875 | 405 | Content Listing | Science & Tech. | 43.970237 |
What's Killing the Key Deer?
From land use to traffic, the deck is being stacked against this endangered species
Roger Di Silvestro
When the rains came that day to palm-shrouded Big Pine Key, the bulldozers were already lined up to go to work, cutting a road across this second-largest of the islands that make up the Fl... | <urn:uuid:d06759f7-d563-4c04-ab23-5bcab3a4e113> | 2.78125 | 3,462 | Knowledge Article | Science & Tech. | 44.017549 |
Patuxent Wildlife Research Center
|Did You Know...||Reference on Site|
|that among all vectors, ticks have the distinction of transmitting the widest diversity of microbes that are harmful to humans?||Ticks can harbor and transmit a wide diversity of pathogens simultaneously. Viruses, bacteria, and protozoan parasites ... | <urn:uuid:4fbc4ebb-3258-4698-bd6c-96039b9845b9> | 3.125 | 1,788 | Content Listing | Science & Tech. | 35.92421 |
Optical Materials by Sol-Gel Method
Tunable Laser samples prepared by the sol-gel method
Owing to the original efforts of the National Aeronautics and Space Administration to supply electric current from silicon photovoltaic (PV) cells to space vehicle, such devices are now available at a price of several US dollars pe... | <urn:uuid:5bd21a7a-2a51-4956-80c7-9b839f40e288> | 3.125 | 1,125 | Academic Writing | Science & Tech. | 25.719783 |
Want to stay on top of all the space news? Follow @universetoday on Twitter
If you could take the entire planet, sort it out into its various elements into piles, you’d have the following: 32% iron, 30% oxygen, 15% silicon, 14% magnesium, 3% sulfur, 2% nickel, and then much smaller piles of calcium, aluminum, and other... | <urn:uuid:15dea686-fec8-44d6-8de0-68a985c5ebf2> | 3.875 | 360 | Truncated | Science & Tech. | 71.11922 |
The dl module defines an interface to the dlopen() function, which is the most common interface on Unix platforms for handling dynamically linked libraries. It allows the program to call arbitrary functions in such a library.
Note: This module will not work unless
sizeof(int) == sizeof(long) == sizeof(char *)
The dl mo... | <urn:uuid:c6af933c-93c4-4ad1-a31c-e1a3aa354b5a> | 2.828125 | 186 | Documentation | Software Dev. | 57.18 |
When energy-saving becomes a game
A smartphone application bringing gaming dimensions to energy awareness has helped householders in Finland, Sweden and Italy reduce their electricity consumption by up to 19%.
Chemicals pollutants threaten health in the Arctic
Studies uncover risks and threats to Arctic inhabitant’s he... | <urn:uuid:849c9036-a685-4acf-a57f-4a8d31521dc7> | 2.703125 | 640 | Content Listing | Science & Tech. | 31.594691 |
Researchers have developed porous materials that can soak up 80 times their volume of carbon dioxide, offering the tantalizing possibility that the greenhouse gas could be cheaply scrubbed from power-plant smokestacks. After the carbon dioxide has been absorbed by the new materials, it could be released through pressur... | <urn:uuid:3933e77e-7bc1-46b2-bd01-ad2efef90339> | 3.09375 | 152 | Personal Blog | Science & Tech. | 38.831898 |
By Daniel Chamovitz
Last month, a group of scientists from around the world announced that they had successfully determined the DNA sequence of the tomato genome. One of the most surprising results of this work was that the lowly tomato, like rice and the common Arabidopsis before it, has more genes than we do – about ... | <urn:uuid:aeb205a2-31c1-482b-a11d-c487012389a3> | 3.484375 | 966 | Personal Blog | Science & Tech. | 43.421046 |
A Skew-t is a graphical representation of the atmosphere in one single column of air. It allows forecasters to gauge nearly everything about the environment: moisture, instability, shear, and environmental temperatures just to sample a few. A seasoned forecaster can quickly glance at a sounding and understand the basic... | <urn:uuid:2b665857-96b0-4704-921e-eb1927cf5590> | 4.0625 | 855 | Knowledge Article | Science & Tech. | 41.889132 |
Electric Rays: a Shocking Use of
The electric rays (order Torpediniformes) have fascinated naturalists since antiquity, being best known for their highly specialized electrogenic organs. These organs are generally kidney-shaped, composed of stacks of 500 to over 1 000 striated muscle plaques that have been modified fro... | <urn:uuid:a896e094-6e56-461e-aeba-9493b42f231b> | 3.5 | 492 | Knowledge Article | Science & Tech. | 24.195334 |
The diagonal fraction
bar in mathematics
. Also called virgule
. This symbol
was used to replace
, sometimes referred to as a vinculum
, due to the typographic
difficulty imposed by the horizontal bar which requires three terraces
An early written example of this usage can be found in a 1718 ledger by Thomas Twining. I... | <urn:uuid:c49cef17-340f-426e-91b0-809c22cd3984> | 3.234375 | 131 | Knowledge Article | Science & Tech. | 27.852774 |
The story of optics goes long back in the past. The oldest instance of
glass being used as a tool of magnification is over 4000 years old.
Glasses were first used as magnifiers and then used as optical aids
for people with poor vision. For the purpose of spectacles, several
refinements had to be made. But magnifiers ha... | <urn:uuid:965c2537-cdc6-4154-a910-c5c15e84bda1> | 3.125 | 126 | Comment Section | Science & Tech. | 51.469208 |
For more than 40 years, scientists have tried to figure out what’s causing large parts of Canada, particularly the Hudson Bay region, to be “missing” gravity. In other words, gravity in the Hudson Bay area and surrounding regions is lower than it is in other parts of the world, a phenomenon first identified in the 1960... | <urn:uuid:2c6b183f-d5a0-4a0a-9640-4f7122a4d162> | 4.25 | 276 | Content Listing | Science & Tech. | 52.026918 |
Major Boundary Currents and Inter-basin Flows
How will the key science questions be addressed?
East Australian Current system -
- Will the EAC strengthen with climate change as predicted?
- Will the North Queensland Current weaken with climate change as predicted?
- Will the bifurcation point and/or dynamics alter in a... | <urn:uuid:356e2947-3168-4af1-a496-df9fbfa43054> | 2.6875 | 507 | Knowledge Article | Science & Tech. | 30.189969 |
In 1952 David Huffman invented data compression by discovering a method to assign the optimal unambiguous encoding to the symbols in a given message. This article explains how data compression works, and Huffman's method in detail, and also explains how the module is implemented. The module implements the Huffman data ... | <urn:uuid:779d17f0-e2ea-409f-9fa6-3127be899d1f> | 2.875 | 218 | Comment Section | Software Dev. | 56.965 |
The answer of blaze comes closest, but is not totally clear:
conditional variables should only be used to signal a change in a condition.
Thread 1 checks a condition. If the condition doesn't meet, he waits on the condition variable until the condition meets. Because the condition is checked first, he shouldn't care wh... | <urn:uuid:eab9daa2-3cf6-4084-a200-a384c8724635> | 2.859375 | 198 | Q&A Forum | Software Dev. | 47.151591 |
John Scannella is a doctoral student at Montana Sate University and the Museum of the Rockies, located in Bozeman, Montana. His research centers on understanding the evolutionary history of Triceratops, a genus of dinosaurs known for a characteristic bony head frill and three horns.
In July 2010 Scannella and John “Jac... | <urn:uuid:33315190-2a28-4134-adfc-2b2aa8153df4> | 3.671875 | 1,310 | Audio Transcript | Science & Tech. | 23.330385 |
Sometimes you'll want to work with more than simply hypothetical future
positions in order to determine whether a collision occurred. This happens
when your objects are zipping along, several units of length at a time, and
might pass through something briefly, but not enough to wind up in it. Consider
the following pic... | <urn:uuid:120dd438-2662-4c3f-9df4-e4e8c1fe0e0b> | 3.796875 | 3,091 | Tutorial | Science & Tech. | 80.943703 |
Figure 4: Optical design used to monitor the biological viablity of the cells using the nanoporous polymer film. On the right are the representative spectra corresponding to the each process. (a) To measure the transmitted light from the sample, illumination (light source) and observation (detector) are aligned on the ... | <urn:uuid:0d3ed8f8-c284-42c3-a41f-7ccc9e168194> | 2.953125 | 181 | Academic Writing | Science & Tech. | 33.25 |
February is Black History Month, and to mark the occasion, we recently sat down with John Johnson, scientist at NASA's Exoplanet Science Institute at the California Institute of Technology in Pasadena. Johnson discussed his research and recent discoveries, and the path that led him to the work he's doing today.
Q: Can ... | <urn:uuid:22cf9517-1248-4f5d-aff7-b8fbe96a700f> | 3.15625 | 1,179 | Audio Transcript | Science & Tech. | 63.023413 |
Relations of G. bulloides and G. glutinata
Only few samples exist in the CLIMAP Holocene data in which both species do not co-occur (Fig. 40). Their relative abundances show some inverse correlation. Globigerina bulloides is more abundant in central upwelling zones and areas of high productivity while G. glutinata is m... | <urn:uuid:a7447cf8-28f5-4a5c-a678-34f305d0514e> | 3.375 | 1,520 | Academic Writing | Science & Tech. | 38.0596 |
- Explore the general resources to get an overview of global warming.
- Use the resources listed for your episode to research your interview and video.
- There are also some resources about producing television interviews that you may find useful.
Global warming – latest evidence
Garnaut report by GetUp!
Measure your c... | <urn:uuid:6e547ac3-fee9-4313-8dbf-c27ebbcb3734> | 2.78125 | 229 | Content Listing | Science & Tech. | 21.986667 |
- Students & Postdocs
- Education & Outreach
- About JILA
Diary of a Binge Eater
Fellow Mitch Begelman and his colleagues came up with the idea of quasistars to explain the origin of the supermassive black holes found at the center of most galaxies. According to Begelman, quasistars formed when massive amounts of gas w... | <urn:uuid:ff1e84d5-543d-4c80-a869-56480c1ffa36> | 3.984375 | 780 | Knowledge Article | Science & Tech. | 43.539387 |
Let S be a set with n elements. Show:
If an (n is subscript) equals the number of subsets of S then an+1 (n+1 is subscript) = 2an (n is subscript)
Use this to prove by induction that an (n is subscript) = 2^n
If S contains n+ 1 members, choose one of them and call it "a". Removing that from S leaves you with set T that... | <urn:uuid:c78c877f-dff3-4212-b079-33ab08e02195> | 3.078125 | 195 | Q&A Forum | Science & Tech. | 94.776403 |
Except for a few trifling practical details, we could easily get around without the consumption of hydrocarbons and the production of greenhouse gases, simply making use of the force of gravity that is constant and inexhaustible. For example, suppose we must journey to a location 30 miles away and at the same elevation... | <urn:uuid:27ac06d0-441b-461f-a4fd-a20cea927972> | 3.765625 | 2,703 | Academic Writing | Science & Tech. | 77.225001 |
Comparative seasonal biogeography of mineralising nannoplankton in the Scotia Sea: Emiliania huxleyi, Fragilariopsis spp. and Tetraparma pelagica
Hinz, D.J.; Poulton, Alex; Nielsdottir, M.C.; Steigenberger, S.; Korb, R.; Achterberg, E.P.; Bibby, T.S.. 2012 Comparative seasonal biogeography of mineralising nannoplankton... | <urn:uuid:4e320a95-e283-449e-a7b5-42aa8cdff1b5> | 2.734375 | 792 | Academic Writing | Science & Tech. | 25.069437 |
How radio waves create the current in antenna in terms of photons? If it is Compton scattering then why is not changed the freuency of photons?
An elementary explanation, at high school level:
The beam of radio wave photons are coherent, as Vladimir said. Coherent means that the electric and magnetic field of each indi... | <urn:uuid:14e85713-449e-4613-9ad9-7acf3ddf7be3> | 3.34375 | 479 | Q&A Forum | Science & Tech. | 42.15087 |
September 6, 2011
A normal linked list can be accessed only at its head. A double-ended queue, or deque (pronounced “deck”), can be accessed at either end. Like a normal list, a deque can be null. New elements can be added at either end, the element at either end of a non-null deque can be fetched, and the element at e... | <urn:uuid:dd948fd6-621f-4ee8-96cf-470b18bb27bc> | 2.9375 | 170 | Personal Blog | Software Dev. | 59.242313 |
Hornets, spider wasps, ants, etc.
This tree diagram shows the relationships between several groups of organisms.
The root of the current tree connects the organisms featured in this tree to their containing group and the rest of the Tree of Life. The basal branching point in the tree represents the ancestor of the othe... | <urn:uuid:064cfcd0-22f6-4344-a662-e30bc08e77a4> | 2.9375 | 500 | Knowledge Article | Science & Tech. | 63.009055 |
Concept 2 Quiz
Hint for Question 7
The Cambrian Explosion represents abundant life forms and a huge expansion in marine biodiversity. The Cambrian period is the first of the Paleozoic era.
This hint opened in a full-sized browser window because your browser either does not support scripting or you have turned scripting... | <urn:uuid:d175d529-3481-4ccf-8e00-d05b69dd5df3> | 3.15625 | 92 | Tutorial | Science & Tech. | 55.122 |
formed over 4.5 billion years ago, and it has been
changing ever since.
Sometimes these changes happen very fast. An earthquake can split the ground in a few seconds. Lava from a volcanic eruption can spread over the side of a volcano in minutes. A heavy rainstorm can flood a neighborhood in a day. These changes are ea... | <urn:uuid:d176ae95-613c-4d81-a927-0892aa090443> | 3.765625 | 153 | Knowledge Article | Science & Tech. | 68.288397 |
Except for the rings
Nebula (M57) is probably the most famous celestial band.
Its classic appearance is understood to be due to perspective -
our view from planet Earth looks down the center of a roughly
barrel-shaped cloud of glowing gas.
But expansive looping structures are seen to extend
the Ring Nebula's familiar c... | <urn:uuid:36577b92-9c43-46f9-843e-1a9cd99f95c5> | 3.125 | 238 | Knowledge Article | Science & Tech. | 44.370476 |
July 13, 1989 – The American burying beetle was listed as endangered under the federal Endangered Species Act. Only two populations — one in eastern Oklahoma and one on a New England island — were known to exist, and only two live specimens had been located over the span of a decade.
September 27, 1991 – The U.S. Fish ... | <urn:uuid:77591bd6-9944-41bd-871f-091a37357243> | 2.90625 | 167 | Knowledge Article | Science & Tech. | 34.156635 |
Boost Format library
The format library provides a class for formatting arguments according
to a format-string, as does printf, but with two major differences
- format sends the arguments to an internal stream, and so is entirely
type-safe and naturally supports all user-defined types.
- The ellipsis (...) can not be u... | <urn:uuid:f0c49306-8337-4f29-bb29-b65a76a155d3> | 2.78125 | 271 | Documentation | Software Dev. | 44.580705 |
A Square has 4 edges, all the same length.
All its vertices (corners) are right-angled.
It has 2 diagonals, both the same length.
It has 4 lines of symmetry, and rotational symmetry of order 4
With this shape it is only necessary to know one of its dimensions, and all the others can be derived from that.
Where (for bre... | <urn:uuid:c4225da7-1f2e-48fc-a1d7-1e309714b121> | 3.09375 | 120 | Knowledge Article | Science & Tech. | 62.257293 |
hello friends ... I will not be breaking the rules of the forum with the question that will, no studio on vacation programmer and I said let's read a book of c + + "how to program in C + +" by Deitel ... and you are the only ones who can give me a hand ... I have good teachers ... to the point, my question
cap.3.9 page... | <urn:uuid:9e1b1fde-6558-40a7-9d5d-0d8d726005ae> | 2.6875 | 350 | Comment Section | Software Dev. | 40.986946 |
Common names: Cicada, Dogday Cicada, Dogday Locust, Harvestfly, Harvestman Cicada, Locust
Scientific name: Order Homoptera, family Cicadidae, many genera and species
Size: Adult--1" to 3"
Identification: The big insects that make all the noise in mid-summer. They have wide, blunt heads with big bulging eyes and clear, ... | <urn:uuid:1657ba7e-dbc3-4aec-8581-7dfcfb93277c> | 3.90625 | 465 | Knowledge Article | Science & Tech. | 64.232308 |
How to Manipulate Files in R
Occasionally, you may want to write a script in R that will traverse a given folder and perform actions on all the data in the files or a subset of files in that folder.
To get a list of files in a specific folder, use list.files() or dir(). These two functions do exactly the same thing, bu... | <urn:uuid:2ba28d48-a5f7-4dd3-bf47-a1719b87508e> | 3.71875 | 994 | Tutorial | Software Dev. | 88.856689 |
See The Hidden Jewels of Appalachia Video Here
If you want to hit paydirt the Appalachian region is the world’s salamander El Dorado—home to over 70 salamander species. Australia and Sub-Saharan Africa have no salamanders, Asia has 27 species the whole of Europe has 36 species. Central and South America have a bunch of... | <urn:uuid:8a3b81f3-40a5-4650-a664-53460e823ee3> | 2.953125 | 399 | Personal Blog | Science & Tech. | 35.780769 |
What Is a Blizzard?
A blizzard is a storm with dense, blowing snow characterized by low visibility and lasting at least three hours.
CREDIT: Ken Graham Photography.
The term "blizzard" is often tossed around when big winter storms blow in. But the National Weather service has an official definition of blizzard:
A blizz... | <urn:uuid:532e47fe-df96-41be-88b6-48bf83b5f221> | 3.765625 | 534 | Knowledge Article | Science & Tech. | 63.775905 |
(Above) Cross-section of the Tswaing crater modified after Brandt, D., (1994), Brandt & Reimold (1999), Partridge & Reimold (1990).
The Tswaing crater has a simple bowl shape with a 1.13 km diameter. The outer rim is composed of shattered rock called breccia and is elevated nearly 60m above the surrounding plains. Most... | <urn:uuid:074621dd-f490-44b1-96f8-a1df825d00b7> | 3.734375 | 681 | Knowledge Article | Science & Tech. | 47.983937 |
SOLAR panels that generate electricity are bulky and expensive. But now an American company says it can provide unobtrusive photovoltaic panels at half the cost of traditional versions.
The new technology will be on show at this month's Olympic Games in Atlanta, Georgia, where the US Department of Energy is building a ... | <urn:uuid:6c949cbe-a7d9-4bb0-bf66-0780ae962526> | 3.53125 | 223 | Truncated | Science & Tech. | 43.624785 |
gravity: This is the term used either for the force exerted by gravity or the acceleration caused by the force of gravity. At the surface of the earth, it has a value of approximately 9.8 meters per second per second, or 32 feet per second per second, depending on the measuring system you choose to use. It also has a v... | <urn:uuid:0de81d02-2bb2-4201-a452-bf9cf6a897d6> | 4.15625 | 1,508 | Tutorial | Science & Tech. | 53.309455 |
Heat and Temperature
This page takes a historical approach to the discussion of temperature and thermometers.Treasures from TPF
Need ideas? Need help? Explore The Physics Front's treasure box of catalogued resources on heat and temperature.SUPER Physics
These workshop-style tutorials and accompanying activities guide s... | <urn:uuid:2ded0c11-c53a-4425-a6e9-277ee908b3f6> | 3.90625 | 2,476 | Tutorial | Science & Tech. | 40.009231 |
I'm not an EM guy, but you might find it easier to understand the words in for something like heat flow.
"Flux" is the total amount of heat flowing through a surface (measured as heat energy / second, i.e. power in watts)
"Flux density" is the flux per unit area, or sometimes the amount of heat generated per unit volum... | <urn:uuid:036f9afd-6c2d-4246-8d3c-4e15e790daf4> | 3.453125 | 183 | Q&A Forum | Science & Tech. | 38.892928 |
|Jun20-12, 12:27 PM||#1|
Confused about image size in plane, concave, or convex mirrors
So I know these equations
1/f = 1/p + 1/i
m = -i/p
f: focal length
p: object distance from mirror
i: image distance from mirror
Let's say that I have an object in front of a concave or convex mirror with the same |f|. p is much larg... | <urn:uuid:b0dd44b7-71ab-405d-ab90-bf7872fc95c9> | 3.25 | 380 | Comment Section | Science & Tech. | 53.660343 |
by Darrel Emerson, AA7FV and G3SYS QST, published by ARRL. Vol 79, No. 2, February 1995, p.21.
(Copyright on the original article is held by the ARRL.)
In July 1991 and in May 1994, partial solar eclipses were visible from the QTH of AA7FV in Tucson Arizona. For both events, a simple Yagi antenna was left pointing in a... | <urn:uuid:a41f860e-0f7d-4f35-8b65-2095f5302d3f> | 2.890625 | 706 | Academic Writing | Science & Tech. | 50.545082 |
University of southern California researchers indicate us a more efficient use of graphene photovoltaicsAugust 2nd, 2010
Is it possible to imagine people powering their cellular phone or music/video device while jogging on a sunny day?
A University of Southern California team has produced flexible transparent carbon at... | <urn:uuid:ac9284a4-392e-4262-b564-d1b5dc037a9e> | 3.6875 | 693 | Personal Blog | Science & Tech. | 23.681231 |
If you watch chimpanzees from different parts of Africa, you’ll see them doing very different things. Some use sticks to extract honey from beehives, while others prefer leaves. Some use sticks as hunting spears and others use them to fish for ants. Some drum on branches to get attention and others rip leaves between t... | <urn:uuid:bf0bc5f8-bb01-4299-a203-8ef057e3cfa1> | 3.40625 | 421 | Personal Blog | Science & Tech. | 46.577935 |
The word geothermal comes from the Greek words geo (earth) and therme (heat). So, geothermal energy is heat from within the earth. We can use the steam and hot water produced inside the earth to heat buildings or generate electricity. Geothermal energy is a renewable energy source because the water is replenished by ra... | <urn:uuid:836dd243-0a35-4e80-8af8-c84f67370de1> | 3.609375 | 178 | Knowledge Article | Science & Tech. | 42.869808 |
You are here:
In this activity, you will work with a reaction between strands of DNA.
Remember that DNA is a sequence of the letters A,C,T, and G. A binds with T and C binds with G. Solutions are specified by the DNA sequence, such as ACAC or TG, and by the concentration in units of micromolar (µM = 10-6M)
Consider mix... | <urn:uuid:315dd9d7-431b-4af2-bd56-0ec1ae2aa552> | 4.125 | 283 | Tutorial | Science & Tech. | 60.427547 |
Rational and basic overview
The reason for having a compiler is that it is useful to have
certain common information between many different web pages
to implement a consistant style amoung the pages. To a certain
extent, this can be implemented by the web server via
Server Side Includes, but that feature is not uniform... | <urn:uuid:eb707964-9b72-4c82-8f86-7ef029da965f> | 3.15625 | 162 | Documentation | Software Dev. | 43.567857 |
The immature insect, or larva, escapes from the egg and acts essentially as an eating machine, gathering nutrients. The larva has no wings or reproductive organs and has a form which does not resemble the adult of the species, but appears to be more like its ancient pre-insect ancestor. The larva's body is generally wo... | <urn:uuid:bdff6ba8-12e8-440b-a895-6a60eb730b51> | 4.15625 | 583 | Knowledge Article | Science & Tech. | 41.748667 |
In a hierarchically structured region, the average density increases as you go down the levels of the hierarchy to smaller and smaller scales. If there are dense star-forming cores at the bottom of the hierarchy, where the densities are largest and the sizes are smallest, then the fractional mass in the form of these c... | <urn:uuid:a98c683f-d40f-494d-8ba3-044570b302db> | 2.84375 | 1,065 | Academic Writing | Science & Tech. | 56.866879 |
|Annu. Rev. Astron. Astrophys. 1998. 36:
Copyright © 1998 by . All rights reserved
2.5. Far-Infrared Continuum
A significant fraction of the bolometric luminosity of a galaxy is absorbed by interstellar dust and re-emitted in the thermal IR, at wavelengths of roughly 10-300 µm. The absorption cross section of the dust ... | <urn:uuid:ed58ba1e-4a9c-481c-9e73-10125ded1f67> | 2.859375 | 1,359 | Academic Writing | Science & Tech. | 42.280311 |
March 9, 2009--
This spider-hunting wasp is one of 19 new species recently found in Australia
--most of them in Western Australia state, considered a "hotbed of biodiversity," scientists announced.
hunt down and paralyze spiders, which are later eaten alive by the wasps' developing larvae.
In all, scientists found 11 s... | <urn:uuid:b74ff056-3a02-498d-8965-628bb2470162> | 3.234375 | 233 | Truncated | Science & Tech. | 31.875714 |
Reading the recent article Electrons Act Like Waves (from the Physical Review Focus series, a highly recommended, lay[wo]man-friendly feed for your newsreader), i've discovered one of those peculiar stories that make the history of physics even more enjoyable than it would be by its purely scientific side alone.
The ar... | <urn:uuid:e4e0cf03-0a78-40c2-8a30-ea5b2a75ef59> | 2.75 | 2,007 | Personal Blog | Science & Tech. | 37.974871 |
Go to the first, previous, next, last section, table of contents.
As was seen in the previous chapter, the GNU configure and build system
uses a number of different files. The developer must write a few files.
The others are generated by various tools.
The system is rather flexible, and can be used in many different wa... | <urn:uuid:05a3df35-0b2d-46a6-8836-be0a8dfe337b> | 3.234375 | 2,570 | Documentation | Software Dev. | 50.72503 |
Category: Jellies, Anemones and kin view all from this category
Description Aequorea victoria, also sometimes called the crystal jelly, is a bioluminescent hydrozoan jellyfish, or hydromedusa, that is found off the west coast of North America. This species is thought to be synonymous with Aequorea aequorea of Osamu Shi... | <urn:uuid:7ed6c298-4b69-4437-be93-a0e355f1f195> | 2.875 | 357 | Knowledge Article | Science & Tech. | 28.200847 |
A spacecraft returning from the Moon and reentering the Earth's atmosphere far exceeds the speed of the ballistic missiles that "leisurely" fall planetward from the fringes of the atmosphere. When spacecraft heading home from the Moon impact the atmosphere, it is like hitting a fiery wall. Temperatures above that of t... | <urn:uuid:56fd864d-3529-4fd9-839a-6b596be053f8> | 3.375 | 667 | Knowledge Article | Science & Tech. | 27.384472 |
Winds of Mars: Aeolian Activity and Landforms
following is a short list of general references on Mars used
in the preparation of this slide set. Numerous others exist,
although care must be taken to keep them in historical context
due to the extremely rapid pace with which our understanding
of the Red Planet has advanc... | <urn:uuid:4a84daf5-a8b8-4feb-a342-575351b947ed> | 2.953125 | 450 | Content Listing | Science & Tech. | 78.632216 |
|Jul8-07, 03:11 AM||#1|
1. The problem statement, all variables and given/known data
A block (mass = 2.4 kg) is hanging from a massless cord that is wrapped around a pulley (moment of inertia = 1.5 x 10-3 kg·m2), as the figure shows. Initially the pulley is prevented from rotating and the block is stationary. Then, the... | <urn:uuid:c6cccfb4-a74a-49b6-a646-b0d662be4865> | 3.390625 | 512 | Comment Section | Science & Tech. | 76.194761 |
Dark Globule in IC 1396
This 22-second animation shows how our view of a dark globule in IC 1396 changes as we move from visible light through near-infrared to mid-infrared wavelengths. The dark globule is virtually opaque at visible-light wavelengths and becomes transparent in the near-infrared. A glowing stellar nurs... | <urn:uuid:1c47238d-6b97-4bbd-b4e3-cbd6ec218342> | 2.96875 | 132 | Content Listing | Science & Tech. | 42.327384 |
SNR 0104-72.3: A supernova remnant located in the Small Magellanic Cloud, about 190,000 light years from Earth.
Caption: A new composite image from NASA's Chandra X-ray Observatory (purple) and Spitzer Space Telescope (red and green) shows a supernova remnant with a different look. This object, known as SNR 0104-72.3 i... | <urn:uuid:e677c8b2-a5f8-4d14-b367-2ccefeb9a108> | 3.34375 | 167 | Truncated | Science & Tech. | 64.246801 |
A pupa (Latin pupa for doll, pl: pupae or pupas) is the life stage of some insects undergoing transformation. The pupal stage is found only in holometabolous insects, those that undergo a complete metamorphosis, going through four life stages; embryo, larva, pupa and imago. (For a list of such insects see Holometabolis... | <urn:uuid:8344f9e3-d95e-4d2e-ad2b-5369d9db0db2> | 3.796875 | 2,027 | Knowledge Article | Science & Tech. | 47.945275 |
Less snowmelt in Antarctica
Climatic change in Antarctica is complicated. The northernmost part of the continent, the Antarctic Peninsula, is warming at extreme rates, while elsewhere the pattern is mixed and in some parts there appears to be little or no warming. Up to a point, we glaciologists don’t mind whether Anta... | <urn:uuid:aeedbef5-83c0-4aaf-9136-4faae229aca9> | 3.625 | 919 | Personal Blog | Science & Tech. | 42.125631 |
SURFRAD includes ancillary data (e.g., cloud cover, moisture) that affect the transfer of solar and thermal infrared radiation to and from the surface. An aerosol optical depth product has been recently added.
Aerosol optical depth is a measure of the extinction of the solar beam by dust and haze. In other words, parti... | <urn:uuid:f08805d1-1a5f-4870-84fc-892a2c595f8b> | 3.28125 | 189 | Knowledge Article | Science & Tech. | 57.970574 |
tis a ``symbol'' and 3 is an ``integer.'' Roughly speaking the objects of ACL2 can be partitioned into the following types:
3, -22/7, #c(3 5/2)Characters
#\A, #\a, #\SpaceStrings
"This is a string."Symbols
'abc, 'smith::abcConses (or Ordered Pairs)
'((a . 1) (b . 2))
When proving theorems it is important to know the ty... | <urn:uuid:3f4e6a02-f3c1-4fcd-bd93-c228a665b3df> | 2.765625 | 454 | Documentation | Software Dev. | 62.872365 |
An anonymous reader sends this quote from an article at Txchnologist:
“The spectacle of a booster rocket lifting off a launch pad atop a mass of brilliant flames and billowing smoke is an iconic image of the Space Age. Such powerful chemical rockets are needed to break the bonds of Earth’s gravity and send spacecraft i... | <urn:uuid:dd0185b7-dd13-4d1e-9626-4407d79c2d29> | 3.3125 | 202 | Truncated | Science & Tech. | 34.383824 |
Coral Reefs, the Human View
Part A: Coral Reef Adventure
Animal, vegetable, or mineral? What exactly is coral? While corals might look more like rocks or plants, they are actually made up of tiny invertebrate animals, called polypscoral polyp: a small individual coral animal with a tube-shaped body and a mouth surround... | <urn:uuid:96d64fca-a302-4889-a8e2-14123d5feeb4> | 3.59375 | 232 | Tutorial | Science & Tech. | 41.978096 |
Megalodon is greek word which means Big Tooth, it is named so because Megalodon shark had quite big tooth sized approx 170mm, these were the biggest and most dangerous killer predator shark ever lived on earth which are believed to got extinct about 28 to 1.5 million years ago.
Here are some interesting facts of these ... | <urn:uuid:067834d4-096a-433f-8daf-0f9f34e1042f> | 3.515625 | 308 | Personal Blog | Science & Tech. | 42.003314 |
The other day one of my colleagues sent me an article about a tummy rocket that runs on stomach acid and jets about doing sensor and/or chemical things. Then I got a pointer to this article [Link] on a wirelessly powered 3mm x 4mm x thin chip that goes into the human circulatory system (no teleporter, sorry!) and putts... | <urn:uuid:589027b4-f319-4996-8f9d-a0dca83d08da> | 2.828125 | 359 | Personal Blog | Science & Tech. | 40.270395 |
Learn more physics!
What is distilled water?
- Samantha (age 9)
Distilled water is water that has been boiled and then recondensed
(that is, the water vapor is turned back into liquid water on a cold
People distill water in order to purify it. Dissolved contaminants
like salts are left behind in the boiling pot as the ... | <urn:uuid:67e93fcd-e00b-4b70-8bc9-56870933c138> | 2.96875 | 144 | Q&A Forum | Science & Tech. | 53.533235 |
They are compounds formed by a metal and hydrogen, in which
the hydrogen has an oxidation number –1.
The hydrides of groups 1 and 2 are more ionic than
covalent. The hydrides of groups 13 and 14 are more covalent than ionic. But
they have the same name, except boron hydride which is named as H + nometal
In Formulae you... | <urn:uuid:7f364e6a-1eac-451b-8d0e-7f4ff8a2a3f6> | 3.578125 | 168 | Tutorial | Science & Tech. | 52.951157 |
Measuring one of the world's largest glaciers
Over two Antarctic summer seasons British Antarctic Survey (BAS) mounted an ambitious and challenging deep-field science campaign to one of the most remote places on Earth. -. For three months of each of the 2007 and 2008 austral summers three scientists and two field assis... | <urn:uuid:4afbfea1-28f9-4503-9fc6-c46f86319a30> | 3.359375 | 172 | Knowledge Article | Science & Tech. | 52.745298 |
Welcome to biology-online.org! Please login to access all site features. Create account.
Log me on automatically each visit
| Page history
| Printable version
(Science: chemistry) A lactone obtained by reduction of phthalyl chloride, as a white crystalline substance; hence, by extension, any one of the series of which ... | <urn:uuid:7a0793cf-2a05-44be-a806-d277887fd2c9> | 2.765625 | 187 | Structured Data | Science & Tech. | 41.878128 |
As part of a physics lab practical exam, you are dropped off in the woods with an EM field meter and a compass. Your task is to find your way to a radio beacon (broadcasting with P=10 kW) somewhere to the north of you. You set your EM field meter to pick up the beacon frequency f=2 kHz.
(a) You are dropped off a distan... | <urn:uuid:b966df23-40e7-462c-96cf-f78d7b1452c5> | 3.890625 | 251 | Q&A Forum | Science & Tech. | 82.441134 |
To use all functions of this page, please activate cookies in your browser.
With an accout for my.chemeurope.com you can always see everything at a glance – and you can configure your own website and individual newsletter.
- My watch list
- My saved searches
- My saved topics
- My newsletter
Convective instability (als... | <urn:uuid:3d61ab75-48a1-4fcf-9b9e-651726cac494> | 3.40625 | 259 | Knowledge Article | Science & Tech. | 24.714493 |
Milton Banana wrote:
Just trying to provide some perspective. Man's carbon is not the only carbon going in this system.
But it is the majority of what is being added to the system.
There is plenty of carbon before we arrived on the scene. Yes, I was refering to the total carbon budget.
Which is a blatent attempt at mis... | <urn:uuid:83d3f613-ee8f-4fc0-b1a0-746afadb2074> | 2.8125 | 844 | Comment Section | Science & Tech. | 61.413279 |
Eureka Tower Radiation Instruments
NOAA Physical Science Division Arctic Observations and Processes group and Environment Canada erected a 10.5 m flux tower in Eureka, Nunavat, Canada in 2007. At the top, we installed upwelling/downwelling shortwave and longwave radiation instruments . Downwelling instruments are facin... | <urn:uuid:b9b448e6-c71c-4272-99b6-93f76494060d> | 3.609375 | 328 | Knowledge Article | Science & Tech. | 36.820816 |
The law connecting the volume of a gas with the temperature was discovered by Gay-Lussac, and independently by Dalton; but it is gene rally attributed to the former chemist. It is : Provided pressure be kept constant, the volume of a gas, measured at 0 degrees C., increases by 1/273 for each rise of 1 degree C..
Or 1 v... | <urn:uuid:55eb0de3-950d-45f0-b65c-fdd0bcde7d91> | 3.84375 | 532 | Knowledge Article | Science & Tech. | 60.580788 |
Evolutionary game of rock-paper-scissors may lead to new species
Washington, Feb 19 (ANI): A new study conducted by researchers at the University of California, Santa Cruz (UCSC), has determined that the evolutionary game of rock-paper-scissors in some animals might lead to the emergence of new species.
The study docum... | <urn:uuid:66f58c14-919c-4ea1-95c2-186ab4be8bce> | 3.453125 | 767 | Truncated | Science & Tech. | 28.687899 |
Diameter of Universe
Name: Thomas P.
What is the diameter of the Universe?
This is a tricky question to answer because the term "diameter" implies that there is
"something" on the "other side", but there is no "other side" so when an astronomer
observes a more distant object (s)he is looking back in time rather more th... | <urn:uuid:a72ff9a5-2dc1-4e2e-8ebd-2f5f675a0a55> | 2.703125 | 183 | Q&A Forum | Science & Tech. | 41.836667 |
Click on any phrase to play the video at that point.Close
Organic chemists make molecules, very complicated molecules, by chopping up a big molecule into small molecules and reverse engineering. And as a chemist, one of the things I wanted to ask my research group a couple of years ago is, could we make a really cool u... | <urn:uuid:27ca9c25-7943-4ab9-8a4b-cfdd37d9079d> | 3.25 | 579 | Audio Transcript | Science & Tech. | 59.582704 |
The blastomussa is a hard coral species of the Blastomussa and Micromussa genus that populates the waters of the Indo-Pacific region, and is also known as a Blasto Coral, Pineapple Coral or Branched Cup Coral. Most can be found on deeper reef slopes where the position provides an excellent shield from rough wave condit... | <urn:uuid:2ede4671-224c-455c-ad39-58d9c78815c5> | 3.25 | 664 | Knowledge Article | Science & Tech. | 29.011182 |
During a tough Massanutten Mountain South Training Run a couple of months ago I entertain good friend Caren Jew with my impromptu lectures on differential equations, on "gold farming" in online multiplayer games, on the rôle of the Nurse in Shakespeare's Romeo and Juliet, on wiki spam, and on the unreasonable effective... | <urn:uuid:4f5fdc10-fc51-4184-a0a9-a16c89984334> | 3 | 387 | Personal Blog | Science & Tech. | 62.875077 |
& Tornado Alley
Sir Isaac Newton discovered in 1666 that the index of refraction of glass was different for different colors of light. This meant, he believed, that any glass lens would have chromatic aberration; i.e., there would be rainbow fringes of any image no matter how sharply focused. Since chromatic aberration... | <urn:uuid:e2306097-2480-47f9-87e6-03a0d95d3939> | 3.65625 | 784 | Knowledge Article | Science & Tech. | 57.380688 |
Not Paying Attention to Planemos? What Makes You Think You Believe in Global Warming?
This month, a set of 'twin' planemos was discovered some 400 light years distant (like we really care, right?) . Designated Oph 162225-240515 (or Oph 1622), the pair was discovered using the European Southern Observatory New Technolog... | <urn:uuid:87a93b56-40aa-411b-a17b-fdc90bc9d7cf> | 3.46875 | 404 | Personal Blog | Science & Tech. | 45.202803 |
|Eukaryotic||a and c2||Phycocyanin or Phycoerythrin||4||0-2||starch and lipids||proteinaceous periplast||2 equal|
|Public Domain||NOAA||Wikimedia Commons, Daniel Vaulot|
Cryptophytes, or cryptomonads, are single-celled algae that have two flagella, used for swimming.
The cryptophytes are single-celled flagellates and h... | <urn:uuid:32844625-615b-4f75-9a95-69cb112db65f> | 3.921875 | 1,157 | Knowledge Article | Science & Tech. | 38.189876 |
MARMAP Bongo Nets 1990-2009Entry ID: MARMAP_BongoNets
Abstract: Abundance and biomass of fish species collected during the day from 1973 to 1980 off the coast of the southeastern United States (Cape Fear, NC to Cape Canaveral, FL).
Purpose: For thirty years, the Marine Resources Research Institute (MRRI) at the South C... | <urn:uuid:53a73f3f-3da4-4208-876a-cdf7f4c5379d> | 2.890625 | 1,356 | Content Listing | Science & Tech. | 63.098162 |
(Submitted March 16, 1998)
Who discovered the quasar and when?
The discovery of quasars was really spread over time. Quasar is a
shortening of "quasi-stellar radio source", and they've also been
called quasi-stellar objects or QSOs. In the late 50s, several
radio sources were matched with very dim optical objects that ... | <urn:uuid:9e2f52eb-3a46-473a-b756-72b4ccf987fd> | 4.15625 | 240 | Q&A Forum | Science & Tech. | 63.661013 |
File:Climate Change Attribution.png
From Global Warming Art
This figure, based on Meehl et al. (2004), shows the ability with which a global climate model (the DOE PCM ) is able to reconstruct the historical temperature record and the degree to which the associated temperature changes can be decomposed into various for... | <urn:uuid:d8d60356-d3a9-4ef6-8553-f27ac6d1bacb> | 3.734375 | 741 | Knowledge Article | Science & Tech. | 47.190133 |
Balloons on Mars
Balloon History on Earth
The first widely recorded, public demonstration of a balloon took place in June of 1783. On this date, a 105-foot circumference balloon, designed by the brothers Joseph and Jacques Montgolfier, was launched in Annonay, France. It rose to an altitude of 6,000 feet. This balloon ... | <urn:uuid:9efc2814-202d-46aa-b2d9-2d16396e1c3d> | 3.9375 | 1,498 | Knowledge Article | Science & Tech. | 60.729109 |
Scientists have used a novel technique to probe the nature of dark energy some 10 billion years into the past. They hope it will bring them closer to an explanation for the strange force that appears to be driving the Universe apart at an accelerating rate. The method relies on bright but distant objects known as quasa... | <urn:uuid:0d0b1bb6-aa5b-473f-a32a-f0af3bee18e4> | 3.546875 | 647 | Comment Section | Science & Tech. | 44.445511 |
How to make a rocket using common cooking ingredients
Use baking soda and vinegar to create a chemical reaction which launches a rocket (a film canister) sky high.
How do differences in surfaces affect the adhesion of tape?
The purpose of this experiment is to examine how differences in surfaces affect the adhesion of ... | <urn:uuid:c6196f9d-4519-4bff-bd09-06e26b577c7a> | 3.84375 | 404 | Content Listing | Science & Tech. | 53.507437 |
From fire scars in the stumps of old-growth oak trees, a team of researchers led by Illinois botanist William E. McClain has given us an amazing glimpse into the history of fire in the U.S. Upper Midwest. The team’s work, published in a recent issue of the journal Castanea, is the most in-depth study of the region’s fi... | <urn:uuid:d73ef6ba-4ee0-4765-8de0-368c0c370bc3> | 3.640625 | 1,177 | Knowledge Article | Science & Tech. | 40.682552 |
Archived:Calculating text width in Qt
This code snippets shows how to use the QFont and QFontMetrics classes to draw a string into the center of the screen and to get the string height and width in pixels.
Note: In order to use this code, you need to have Qt for Symbian installed on your platform.
- Install latest Qt f... | <urn:uuid:764f495e-5459-4624-a80e-50e606011e24> | 3.1875 | 284 | Documentation | Software Dev. | 61.520943 |
Disulfide bonds are an essential stabilizing feature of many proteins. More than 50% of human ER proteins are estimated to contain disulfide bonds (dsb) and the majority of secreted proteins also contain dsbs.
Using bacteria to produce these proteins efficiently presents a significant challenge because the correct pair... | <urn:uuid:a9cfca30-9e7f-46de-a6c9-b6cc4e03daec> | 2.703125 | 736 | Knowledge Article | Science & Tech. | 25.005991 |
All Sather 1.1 implementations must support the language kernel defined in the last chapter. This chapter defines language extensions which may not be meaningful on every platform or which can be very difficult to implement. For example, platforms without a Fortran compiler need not implement the Fortran language inter... | <urn:uuid:9d60e45f-6801-4e39-a7ed-e1df5c0b20bb> | 2.8125 | 164 | Documentation | Software Dev. | 26.533141 |