text stringlengths 11 1.65k | source stringlengths 38 44 |
|---|---|
Hyperconjugation can be used to rationalize a variety of chemical phenomena, including the anomeric effect, the gauche effect, the rotational barrier of ethane, the beta-silicon effect, the vibrational frequency of exocyclic carbonyl groups, and the relative stability of substituted carbocations and substituted carbon ... | https://en.wikipedia.org/wiki?curid=2729378 |
Hyperconjugation The effect is almost an order of magnitude weaker than the case of alkyl substitution on carbocations (σ→p), since an unfilled p orbital is lower in energy, and, therefore, better energetically matched to a σ bond. When this effect manifests in the formation of the more substituted product in thermodyn... | https://en.wikipedia.org/wiki?curid=2729378 |
Hyperconjugation The strain of five-membered rings increased with a decrease degree of unsaturation. This was a surprising result that was further investigated in later work with cyclic acid anhydrides and lactones. Cyclic molecules like benzene and its derivatives were also studied, as their behaviors were different f... | https://en.wikipedia.org/wiki?curid=2729378 |
Hyperconjugation However, they interpreted the data differently by taking into account the hyperconjugation stabilization. To quantify hyperconjugation effect, they designed the following isodesmic reactions in 1-butyne and 1-butene. Deleting the hyperconjugative interactions gives virtual states that have energies tha... | https://en.wikipedia.org/wiki?curid=2729378 |
Hyperconjugation Fernández and Frenking reported that the methyl, hydroxyl, and amino substituents resulted in a decrease in ΔE from the parent 2-propenal. Conversely, halide substituents of increasing atomic mass resulted in increasing ΔE. Because both the enone study and Hammett analysis study substituent effects (al... | https://en.wikipedia.org/wiki?curid=2729378 |
Hyperconjugation In their 2001 paper, however, Pophristic and Goodman revealed that this explanation may be too simplistic. Goodman focused on three principal physical factors: hyperconjugative interactions, exchange repulsion defined by the Pauli exclusion principle, and electrostatic interactions (Coulomb interaction... | https://en.wikipedia.org/wiki?curid=2729378 |
Hyperconjugation Thanks to this work, the following model of the stabilization of the staggered conformation of ethane is now more accepted: can also explain several other phenomena whose explanations may also not be as intuitive as that for the rotational barrier of ethane. One such example is the explanations for cer... | https://en.wikipedia.org/wiki?curid=2729378 |
ABTS In biochemistry, (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) is a chemical compound used to observe the reaction kinetics of specific enzymes. A common use for it is in the enzyme-linked immunosorbent assay (ELISA) to detect for binding of molecules to each other. It is commonly used as a substrate wi... | https://en.wikipedia.org/wiki?curid=2730088 |
ABTS is also frequently used by the food industry and agricultural researchers to measure the antioxidant capacities of foods. In this assay, is converted to its radical cation by addition of sodium persulfate. This radical cation is blue in color and absorbs light at 734 nm. The radical cation is reactive towards most... | https://en.wikipedia.org/wiki?curid=2730088 |
Glide plane In geometry and crystallography, a glide plane (or transflection) is a symmetry operation describing how a reflection in a plane, followed by a translation parallel with that plane, may leave the crystal unchanged. Glide planes are noted by "a", "b" or "c", depending on which axis the glide is along. If the... | https://en.wikipedia.org/wiki?curid=2731261 |
Glide plane The "n" glide plane may be indicated by diagonal arrow when it is parallel to the plane of the screen or a dashed-dotted line when the glide plane is perpendicular to the plane of the screen. A "d" glide plane may be indicated by a diagonal half-arrow if the glide plane is parallel to the plane of the scree... | https://en.wikipedia.org/wiki?curid=2731261 |
Glide plane Combining two equal glide plane operations gives a pure translation with a translation vector that is twice that of the glide plane operation, so the even powers of the glide plane operation form a translation group. In the case of glide plane symmetry, the symmetry group of an object contains a glide plane... | https://en.wikipedia.org/wiki?curid=2731261 |
Constrained geometry complex In organometallic chemistry, a "constrained geometry complex" (CGC) is a kind of catalyst used for the production of polyolefins such as polyethylene and polypropylene. The catalyst was one of the first major departures from metallocene-based catalysts and ushered in much innovation in the ... | https://en.wikipedia.org/wiki?curid=2732285 |
Constrained geometry complex The catalytic systems based on CGCs, however, display incorporation of alpha-olefin comonomers to a greater extend than comparable metallocene based systems. This superiority of CGCs in copolymerisation reactions is ascribed to (i) a high accessibility of the reactive centre and (ii) a low ... | https://en.wikipedia.org/wiki?curid=2732285 |
Sørensen formol titration The Sørensen formol titration(SFT) invented by S. P. L. Sørensen in 1907 is a titration of an amino acid with potassium hydroxide in the presence of formaldehyde. It is used in the determination of protein content in samples. If instead of an amino acid an ammonium salt is used the reaction pr... | https://en.wikipedia.org/wiki?curid=2732992 |
Prelog strain Transannular strain can also be demonstrated in other cyclo-organic molecules, such as lactones, lactams, ethers, cycloalkenes, and cycloalkynes. These compounds are not without significance, since they are particularly useful in the study of transannular strain. Furthermore, transannular interactions are... | https://en.wikipedia.org/wiki?curid=2733186 |
Prelog strain Rates of reaction can be affected by the size of rings. Essentially each reaction should be studied on a case by case basis but some general trends have been seen. Molecular mechanics calculations of strain energy differences SI between a sp2 and sp3 state in cycloalkanes show linear correlations with ra... | https://en.wikipedia.org/wiki?curid=2733186 |
Prelog strain The regioselectivity of water elimination is highly influenced by ring size. When water is eliminated from cyclic tertiary alcohols by an E1 route, three major products are formed. The semicyclic isomer (so-called because the double bond is shared by a ring atom and an exocyclic atom) and the (E) endocycl... | https://en.wikipedia.org/wiki?curid=2733186 |
Prelog strain This indicates that strain within the cyclic transition states is higher if there are more carbons in the ring. Since transannular strain is the largest source of strain in rings this size, the larger enthalpies of activation result in much slower cyclizations due to transannular interactions in the cycli... | https://en.wikipedia.org/wiki?curid=2733186 |
Aqueous two-phase system Aqueous biphasic systems (ABS) or aqueous two-phase systems (ATPS) are clean alternatives for traditional organic-water solvent extraction systems. ABS are formed when either two polymers, one polymer and one kosmotropic salt, or two salts (one chaotropic salt and the other a kosmotropic salt) ... | https://en.wikipedia.org/wiki?curid=2733362 |
Aqueous two-phase system It is a common observation that when oil and water are poured into the same container, they separate into two phases or layers, because they are immiscible. In general, aqueous (or water-based) solutions, being polar, are immiscible with non-polar organic solvents (chloroform, toluene, hexane e... | https://en.wikipedia.org/wiki?curid=2733362 |
Aqueous two-phase system Specificity may be further increased by tagging ligands specific to the desired enzyme, onto the polymer. This results in a preferential binding of the enzyme to the polymer, increasing the effectiveness of the extraction. One major disadvantage, however, is the cost of materials involved, name... | https://en.wikipedia.org/wiki?curid=2733362 |
Ethyl bromoacetate is the chemical compound with the formula CHBrCOCH. It is the ethyl ester of bromoacetic acid and is prepared in two steps from acetic acid. It is a lachrymator and has a fruity, pungent odor. It is also a highly toxic alkylating agent and may be fatal if inhaled. is listed by the World Health Organi... | https://en.wikipedia.org/wiki?curid=2733421 |
Sour crude oil is crude oil containing a high amount of the impurity sulfur. It is common to find crude oil containing some impurities. When the total sulfur level in the oil is more than 0.5% the oil is called "sour". The impurities need to be removed before this lower-quality crude can be refined into petrol, thereby... | https://en.wikipedia.org/wiki?curid=2733552 |
Optical molasses is a laser cooling technique that can cool neutral atoms to temperatures lower than a magneto-optical trap (MOT). An optical molasses consists of 3 pairs of counter-propagating circularly polarized laser beams intersecting in the region where the atoms are present. The main difference between optical m... | https://en.wikipedia.org/wiki?curid=2734556 |
Optical molasses Counterpropagating beams of circularly polarized light cause a standing wave, where the light polarization is linear but the direction rotates along the direction of the beams at a very fast rate. Atoms moving in the spatially varying linear polarisation have a higher probability density of being in a ... | https://en.wikipedia.org/wiki?curid=2734556 |
Worm-like chain The worm-like chain (WLC) model in polymer physics is used to describe the behavior of polymers that are semi-flexible: fairly stiff with successive segments pointing in roughly the same direction, and with persistence length within a few orders of magnitude of the polymer length. The WLC model is the c... | https://en.wikipedia.org/wiki?curid=2736555 |
Worm-like chain This is caused by thermal fluctuations, which result in a coiled, random configuration of the undisturbed polymer. The polymer's orientation correlation function can then be solved for, and it follows an exponential decay with decay constant 1/P: formula_14 A useful value is the mean square end-to-end d... | https://en.wikipedia.org/wiki?curid=2736555 |
Worm-like chain Here, the contour length is represented by formula_2, the persistence length by formula_10, the extension is represented by formula_24, and external force is represented by formula_25. Laboratory tools such as atomic force microscopy (AFM) and optical tweezers have been used to characterize the force-de... | https://en.wikipedia.org/wiki?curid=2736555 |
Worm-like chain For the low-force regime (F < about 10 pN), the following interpolation formula was derived: formula_31. For the higher-force regime, where the polymer is significantly extended, the following approximation is valid: formula_32. More accurate interpolation formulas for the force-extension and extension-... | https://en.wikipedia.org/wiki?curid=2736555 |
Myristoylation is a lipidation modification where a myristoyl group, derived from myristic acid, is covalently attached by an amide bond to the alpha-amino group of an N-terminal glycine residue. Myristic acid is a 14-carbon saturated fatty acid (14:0) with the systematic name of "n"-Tetradecanoic acid. This modificati... | https://en.wikipedia.org/wiki?curid=2736775 |
Myristoylation In vertebrates, this modification is carried about by two NMTs, NMT1 and NMT2, both of which are members of the GCN5 acetyltransferase superfamily. The crystal structure of NMT reveals two identical subunits, each with its own myristoyl CoA binding site. Each subunit consists of a large saddle-shaped β-s... | https://en.wikipedia.org/wiki?curid=2736775 |
Myristoylation Co-translational and post-translational covalent modifications enable proteins to develop higher levels of complexity in cellular function, further adding diversity to the proteome. The addition of myristoyl-CoA to a protein can occur during protein translation or after. During co-translational addition ... | https://en.wikipedia.org/wiki?curid=2736775 |
Myristoylation The basic patch allows for favorable electrostatic interactions to occur between the negatively charged phospholipid heads of the membrane and the positive surface of the associating protein. This allows tighter association and directed localization of proteins. Myristoyl-conformational switches can come... | https://en.wikipedia.org/wiki?curid=2736775 |
Myristoylation This specific dual modification is important for G protein-coupled receptor pathways and is referred to as the dual fatty acylation switch. is often followed by phosphorylation of nearby residues. Additional phosphorylation of the same protein can decrease the electrostatic affinity of the myristoylated ... | https://en.wikipedia.org/wiki?curid=2736775 |
Myristoylation The pro-apoptotic BH3-interacting domain death agonist (Bid) is one such protein that once myristoylated, translocates to the mitochondria where it prompts the release of cytochrome c leading to cell death. Actin, gelsolin and p21-activated kinase 2 PAK2 are three other proteins that are myristoylated fo... | https://en.wikipedia.org/wiki?curid=2736775 |
Myristoylation Utilizing the myristoyl-electrostatic switch, including a basic patch on the matrix protein, gag can assemble at lipid rafts at the plasma membrane for viral assembly, budding and further maturation. In order to prevent viral infectivity, myristoylation of the matrix protein could become a good drug targ... | https://en.wikipedia.org/wiki?curid=2736775 |
Intelligent Small World Autonomous Robots for Micro-manipulation (I-Swarm) is a European research project to develop millimeter-scale robots for dangerous activities. It is coordinated by Jörg Seyfried at the University of Karlsruhe in Germany. The robots operate on solar power and can communicate between each other. T... | https://en.wikipedia.org/wiki?curid=2736877 |
Naphthalen-1,8-diyl 1,3,2,4-dithiadiphosphetane 2,4-disulfide A compound related to Lawesson's reagent named NpPS has been formed by the reaction of 1-bromonaphthalene with PS, this is a 1,3,2,4-dithiadiphosphetane 2,4-disulfide which has a naphth-1,8-diyl group holding the two phosphorus atoms together. The mechanism ... | https://en.wikipedia.org/wiki?curid=2737578 |
Gasworks A gasworks or gas house is an industrial plant for the production of flammable gas. Many of these have been made redundant in the developed world by the use of natural gas, though they are still used for storage space. Coal gas was introduced to Great Britain in the 1790s as an illuminating gas by the Scottish... | https://en.wikipedia.org/wiki?curid=2739199 |
Gasworks The tar produced was then held in a tar well/tank which was also used to store liquor. An impeller or pump was used to increase the gas pressure before scrubbing. Exhausters were optional components and could be placed anywhere along the purifying process but were most often placed after the condensers and imm... | https://en.wikipedia.org/wiki?curid=2739199 |
Gasworks The gas holder usually consisted of an upturned steel bell contained within a large frame that guided it as it rose and fell depending on the amount of gas it contained. The by-products of gas-making, such as coke, coal tar, ammonia and sulfur had many uses. For details, see coal gas. Coal gas is no longer mad... | https://en.wikipedia.org/wiki?curid=2739199 |
Gasworks Such works were established at the Macdonaldtown Carriage Sheds, Newcastle, Bathurst, Junee and Werris Creek. These plants followed on from the works of a private supplier which the railway took over in 1884. Gas was also transported in special travelling gas reservoir wagons from the gasworks to stationary re... | https://en.wikipedia.org/wiki?curid=2739199 |
Gasworks The site itself has been synonymous with economic growth and benefit to Brisbane and Queensland with the success of the gasworks facilitating further development of the Newstead/Teneriffe area to include the James Hardie fibro-cement manufacturing plant, Shell Oil plant, Brisbane Water and Sewerage Depot and e... | https://en.wikipedia.org/wiki?curid=2739199 |
Gasworks Located in Athens, Greece Technopolis (Gazi) is a gasworks converted to an exhibition space. The Gas Museum in Leicester, UK is operated by The National Gas Museum Trust. Gas Works Park is a public park in Seattle, Washington. The Warsaw Museum is a museum in Warsaw, Poland. | https://en.wikipedia.org/wiki?curid=2739199 |
Nanoelectrochemistry is a branch of electrochemistry that investigates the electrical and electrochemical properties of materials at the nanometer size regime. plays significant role in the fabrication of various sensors, and devices for detecting molecules at very low concentrations. Two transport mechanisms are funda... | https://en.wikipedia.org/wiki?curid=2740204 |
Nanoelectrochemistry <br> According to TSK model, surface atoms in nanocrystals can occupy terrace, step or kink positions: each site has a different tendency to adsorb reactants and to let them move along the surface. Generally, sites having lower coordination number (steps and kinks) are more reactive due to their hi... | https://en.wikipedia.org/wiki?curid=2740204 |
Nanoelectrochemistry The most used characterization techniques are: There are mainly two properties that distinguish nanoelectrodes from electrodes: smaller RC constant and faster mass transfer. The former allows measurements to be made in high-resistance solutions because they offer less resistance, the latter, due to... | https://en.wikipedia.org/wiki?curid=2740204 |
Molten Man (Mark Raxton) is a fictional character, a supervillain appearing in American comic books published by Marvel Comics. A creature based on "Molten Man" appeared in the 2019 Marvel Cinematic Universe film "", which was actually an illusion created by a series of drones operated by Mysterio. The character was cr... | https://en.wikipedia.org/wiki?curid=2741033 |
Molten Man Eventually, Molten Man's body begins to give off intense heat and to consume itself. His metal skin became molten, and he steals meteor fragments from a museum to attempt a cure. An encounter with Spider-Man resulted in his submergence in the polluted East River, which temporarily reversed the deterioration.... | https://en.wikipedia.org/wiki?curid=2741033 |
Molten Man was then kidnapped along with Liz, Normie Osborn, and Spider-Man by Harry Osborn, who had suffered a mental lapse, making him the evil Green Goblin once again. was saved by Spider-Man. and Spider-Man have since become friends, and has occasionally used his powers to aid Spider-Man against other supervillains... | https://en.wikipedia.org/wiki?curid=2741033 |
Molten Man When Harry Osborn comes to visit Liz and Normie, he and Liz argue. Hearing Liz speak Harry's name, Raxton awakens and attacks him, screaming that Harry has hurt his family for the last time, and will "die for real". Spider-Man intervenes, but he has trouble fighting Raxton, whose powers have grown out of con... | https://en.wikipedia.org/wiki?curid=2741033 |
Molten Man His skin completely absorbed the experimental alloy, turning all of the external tissues of his body into a solid metallic substance, as well as the trunks, belt, and boots he was wearing at the time of the accident. As a result, possesses superhuman strength and his skin is composed of a frictionless metal ... | https://en.wikipedia.org/wiki?curid=2741033 |
Molten Man He asks Mary Jane Watson on a date. She reluctantly accepts, but spends most of the evening talking about Peter Parker, who has just broken up with her. Raxton remains a gentleman the entire time. Later, he encounters Mary Jane at the mall, and upon learning that the boy she was with was Peter, tells her "Go... | https://en.wikipedia.org/wiki?curid=2741033 |
Phosphorescent organic light-emitting diode Phosphorescent organic light-emitting diodes (PHOLED) are a type of organic light-emitting diode (OLED) that use the principle of phosphorescence to obtain higher internal efficiencies than fluorescent OLEDs. This technology is currently under development by many industrial a... | https://en.wikipedia.org/wiki?curid=2741241 |
Phosphorescent organic light-emitting diode Hence it would be expected that in fluorescent OLEDs only the formation of singlet excitons results in the emission of useful radiation, placing a theoretical limit on the internal quantum efficiency (the percentage of excitons formed that result in emission of a photon) of 2... | https://en.wikipedia.org/wiki?curid=2741241 |
Phosphorescent organic light-emitting diode The United States Department of Energy has recognized the potential for massive energy savings via the use of this technology and therefore has awarded $200,000 USD in contracts to develop PHOLED products for general lighting applications. One problem that currently hampers t... | https://en.wikipedia.org/wiki?curid=2741241 |
X-ray absorption spectroscopy (XAS) is a widely used technique for determining the local geometric and/or electronic structure of matter. The experiment is usually performed at synchrotron radiation facilities, which provide intense and tunable X-ray beams. Samples can be in the gas phase, solutions, or solids. XAS dat... | https://en.wikipedia.org/wiki?curid=2745361 |
X-ray absorption spectroscopy XAS methodology can be broadly divided into four experimental categories that can give complementary results to each other: metal K-edge, metal L-edge, ligand K-edge, and EXAFS. XAS is a technique used in different scientific fields including molecular and condensed matter physics, materia... | https://en.wikipedia.org/wiki?curid=2745361 |
Thermodynamic state For thermodynamics, a thermodynamic state of a system is its condition at a specific time, that is fully identified by values of a suitable set of parameters known as state variables, state parameters or thermodynamic variables. Once such a set of values of thermodynamic variables has been specified... | https://en.wikipedia.org/wiki?curid=2747182 |
Thermodynamic state The number of state variables required to specify the thermodynamic state depends on the system, and is not always known in advance of experiment; it is usually found from experimental evidence. Always the number is two or more; usually it is not more than some dozen. Though the number of state vari... | https://en.wikipedia.org/wiki?curid=2747182 |
Thermodynamic state For non-equilibrium thermodynamics, a suitable set of identifying state variables includes some macroscopic variables, for example a non-zero spatial gradient of temperature, that indicate departure from thermodynamic equilibrium. Such non-equilibrium identifying state variables indicate that some n... | https://en.wikipedia.org/wiki?curid=2747182 |
Thermodynamic state In the most commonly cited simple example, an ideal gas, the thermodynamic variables would be any three variables out of the following four: amount of substance, pressure, temperature, and volume. Thus the thermodynamic state would range over a three-dimensional state space. The remaining variable, ... | https://en.wikipedia.org/wiki?curid=2747182 |
Thermodynamic state A few different types of equilibrium are listed below. | https://en.wikipedia.org/wiki?curid=2747182 |
Biological thermodynamics is the quantitative study of the energy transductions that occur in or between living organisms, structures, and cells and of the nature and function of the chemical processes underlying these transductions. may address the question of whether the benefit associated with any particular phenoty... | https://en.wikipedia.org/wiki?curid=2747470 |
Biological thermodynamics Annual energy captured by photosynthesis in green plants is about 4% of the total sunlight energy that reaches Earth. The energy transformations in biological communities surrounding hydrothermal vents are exceptions; they oxidize sulfur, obtaining their energy via chemosynthesis rather than p... | https://en.wikipedia.org/wiki?curid=2747470 |
Biological thermodynamics No matter what the type of living species, all living organisms must capture, transduce, store, and use energy to live. The relationship between the energy of the incoming sunlight and its wavelength or frequency is given by where "h" is the Planck constant (6.63x10Js) and "c" is the speed of ... | https://en.wikipedia.org/wiki?curid=2747470 |
Biological thermodynamics Diversity can also be argued to be a diffusion process that diffuses toward a dynamic equilibrium to maximize entropy. Therefore, thermodynamics can explain the direction and rate of evolution along with the direction and rate of succession. The First Law of Thermodynamics is a statement of th... | https://en.wikipedia.org/wiki?curid=2747470 |
Biological thermodynamics Living organisms are often mistakenly believed to defy the Second Law because they are able to increase their level of organization. To correct this misinterpretation, one must refer simply to the definition of systems and boundaries. A living organism is an open system, able to exchange both ... | https://en.wikipedia.org/wiki?curid=2747470 |
Biological thermodynamics where: The change in Gibbs Free Energy can be used to determine whether a given chemical reaction can occur spontaneously. If ∆"G" is negative, the reaction can occur spontaneously. Likewise, if ∆"G" is positive, the reaction is nonspontaneous. Chemical reactions can be “coupled” together if t... | https://en.wikipedia.org/wiki?curid=2747470 |
Synergetics (Haken) Synergetics is an interdisciplinary science explaining the formation and self-organization of patterns and structures in open systems far from thermodynamic equilibrium. It is founded by Hermann Haken, inspired by the laser theory. Haken's interpretation of the laser principles as self-organization ... | https://en.wikipedia.org/wiki?curid=2748227 |
Synergetics (Haken) This far-reaching macroscopic order is independent of the details of the microscopic interactions of the subsystems. This supposedly explains the self-organization of patterns in so many different systems in physics, chemistry and biology. "[...] the statistical properties of laser light change qual... | https://en.wikipedia.org/wiki?curid=2748227 |
Synergetics (Haken) ] This equation tells us that the amplitude of the dipoles, which is proportional to A, is instantaneously given by the field amplitude B(t) (and by the fluctuating force). This is probably the simplest example of a principle which has turned out to be of fundamental importance in synergetics and wh... | https://en.wikipedia.org/wiki?curid=2748227 |
Wöhler synthesis The is the conversion of ammonium cyanate into urea. This chemical reaction was described in 1828 by Friedrich Wöhler. It is often cited as the starting point of modern organic chemistry. Although the Wöhler reaction concerns the conversion of ammonium cyanate, this salt appears only as an (unstable) i... | https://en.wikipedia.org/wiki?curid=2749404 |
Wöhler synthesis Prior to the Wöhler synthesis, the work of John Dalton and Jöns Jacob Berzelius had already convinced chemists that organic and inorganic matter obey the same chemical laws. It took until 1845 when Kolbe reported another inorganic – organic conversion (of carbon disulfide to acetic acid) before vitalis... | https://en.wikipedia.org/wiki?curid=2749404 |
Dielectric complex reluctance is a scalar measurement of a passive dielectric circuit (or element within that circuit) dependent on sinusoidal voltage and sinusoidal electric induction flux, and this is determined by deriving the ratio of their complex "effective" amplitudes. The units of dielectric complex reluctance ... | https://en.wikipedia.org/wiki?curid=2751642 |
Myzocytosis (from Greek: myzein, (') meaning "to suck" and kytos (') meaning "container", hence referring to "cell") is a method of feeding found in some heterotrophic organisms. It is also called "cellular vampirism" as the predatory cell pierces the cell wall and/or cell membrane of the prey cell with a feeding tube,... | https://en.wikipedia.org/wiki?curid=2755147 |
Phenomenology (physics) In physics, phenomenology is the application of theoretical physics to experimental data by making quantitative predictions based upon known theories. It is in contrast to experimentation in the scientific method, in which the goal of the experiment is to test a scientific hypothesis instead of ... | https://en.wikipedia.org/wiki?curid=2757018 |
Phenomenology (physics) Phenomenological analyses, in which one studies the experimental consequences of adding the most general set of beyond-the-Standard-Model effects in a given sector of the Standard Model, usually parameterized in terms of anomalous couplings and higher-dimensional operators. In this case, the ter... | https://en.wikipedia.org/wiki?curid=2757018 |
Retroreflective sheeting is flexible retroreflective material primarily used to increase the nighttime conspicuity of traffic signs, high-visibility clothing, and other items so they are safely and effectively visible in the light of an approaching driver's headlamps. They are also used as a material to increase the sc... | https://en.wikipedia.org/wiki?curid=2761068 |
Retroreflective sheeting for road signs is categorized by construction and performance specified by technical standards such as ASTM D4956-11a.; various types give differing levels of retroreflection, effective view angles, and lifespan. Sheeting has replaced button copy as the predominant type of retroreflector used i... | https://en.wikipedia.org/wiki?curid=2761068 |
Fire in the hole "Fire in the hole" is a warning that an explosive detonation in a confined space is imminent. It originated with miners, who needed to warn their fellows that a charge had been set. The phrase appears in this sense in state mining regulations, in military and corporate procedures, and in various mining... | https://en.wikipedia.org/wiki?curid=2764113 |
Phase-contrast imaging is a method of imaging that has a range of different applications. It exploits differences in the refractive index of different materials to differentiate between structures under analysis. In conventional light microscopy, phase contrast can be employed to distinguish between structures of simil... | https://en.wikipedia.org/wiki?curid=2764446 |
Phase-contrast imaging In biology, it is employed in viewing unstained biological samples, making it possible to distinguish between structures that are of similar transparency or refractive indices. In geology, phase contrast is exploited to highlight differences between mineral crystals cut to a standardised thin sec... | https://en.wikipedia.org/wiki?curid=2764446 |
Phase-contrast imaging The advantage of these methods compared to normal absorption-contrast X-ray imaging is higher contrast that makes it possible to see smaller details. One disadvantage is that these methods require more sophisticated equipment, such as synchrotron or microfocus X-ray sources, x-ray optics, and hig... | https://en.wikipedia.org/wiki?curid=2764446 |
Phase-contrast imaging A difference in the refractive index between a detail and its surroundings causes a phase shift between the light wave that travels through the detail and that which travels outside the detail. An interference pattern results, marking out the detail. This method has been used to image Precambrian... | https://en.wikipedia.org/wiki?curid=2764446 |
Phase-contrast imaging Instead, because the combination of contrasts due to multiple diffracting elements and planes and the transmitted beam is complex, computer simulations are used to determine what sort of contrast different structures may produce in a phase-contrast image. Thus, a reasonable amount of information ... | https://en.wikipedia.org/wiki?curid=2764446 |
Phase-contrast imaging Thus, a very low degree of lens aberration is also a requirement for HRTEMs, and advances in spherical aberration (Cs) correction have enabled a new generation of HRTEMs to reach resolutions once thought impossible. | https://en.wikipedia.org/wiki?curid=2764446 |
Solvay Conference The International Solvay Institutes for Physics and Chemistry, located in Brussels, were founded by the Belgian industrialist Ernest Solvay in 1912, following the historic invitation-only 1911 "Conseil Solvay", considered a turning point in the world of physics. The Institutes coordinate conferences, ... | https://en.wikipedia.org/wiki?curid=2764597 |
Solvay Conference Perhaps the most famous conference was the Fifth on "Electrons and Photons" held from 24 to 29 October 1927, where the world's most notable physicists met to discuss the newly formulated quantum theory. The leading figures were Albert Einstein and Niels Bohr. 17 of the 29 attendees were or became Nobe... | https://en.wikipedia.org/wiki?curid=2764597 |
Molecular motor Molecular motors are natural (biological) or artificial molecular machines that are the essential agents of movement in living organisms. In general terms, a motor is a device that consumes energy in one form and converts it into motion or mechanical work; for example, many protein-based molecular motor... | https://en.wikipedia.org/wiki?curid=2765047 |
Molecular motor " These synthetic molecular motors currently suffer many limitations that confine their use to the research laboratory. However, many of these limitations may be overcome as our understanding of chemistry and physics at the nanoscale increases. One step toward understanding nanoscale dynamics was made w... | https://en.wikipedia.org/wiki?curid=2765047 |
Continuous distillation Continuous distillation, a form of distillation, is an ongoing separation in which a mixture is continuously (without interruption) fed into the process and separated fractions are removed continuously as output streams. Distillation is the separation or partial separation of a liquid feed mixtu... | https://en.wikipedia.org/wiki?curid=2766531 |
Continuous distillation In practice when there are multiple distillate fractions, the distillate exit points are located at different heights on a fractionating column. The bottoms fraction can be taken from the bottom of the distillation column or unit, but is often taken from a reboiler connected to the bottom of the... | https://en.wikipedia.org/wiki?curid=2766531 |
Continuous distillation It is often not worthwhile separating the components in these fractions any further based on product requirements and economics. Industrial distillation is typically performed in large, vertical cylindrical columns (as shown in images 1 and 2) known as "distillation towers" or "distillation colu... | https://en.wikipedia.org/wiki?curid=2766531 |
Continuous distillation The "lightest" products (those with the lowest boiling point or highest volatility) exit from the top of the columns and the "heaviest" products (the bottoms, those with the highest boiling point) exit from the bottom of the column. The overhead stream may be cooled and condensed using a water-c... | https://en.wikipedia.org/wiki?curid=2766531 |
Continuous distillation Since a continuous distillation unit is fed constantly with a feed mixture and not filled all at once like a batch distillation, a continuous distillation unit does not need a sizable distillation pot, vessel, or reservoir for a batch fill. Instead, the mixture can be fed directly into the colum... | https://en.wikipedia.org/wiki?curid=2766531 |
Continuous distillation If the feed is from a source at a pressure higher than the distillation column pressure, it is simply piped into the column. Otherwise, the feed is pumped or compressed into the column. The feed may be a superheated vapor, a saturated vapor, a partially vaporized liquid-vapor mixture, a saturate... | https://en.wikipedia.org/wiki?curid=2766531 |
Continuous distillation Large-scale industrial fractionation towers use reflux to achieve more efficient separation of products. Reflux refers to the portion of the condensed overhead liquid product from a distillation tower that is returned to the upper part of the tower as shown in images 3 and 4. Inside the tower, t... | https://en.wikipedia.org/wiki?curid=2766531 |
Continuous distillation The stage at the tower bottom has the highest pressure and temperature. Progressing upwards in the tower, the pressure and temperature decreases for each succeeding stage. The vapor–liquid equilibrium for each feed component in the tower reacts in its unique way to the different pressure and tem... | https://en.wikipedia.org/wiki?curid=2766531 |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.