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Countercurrent chromatography CCD was used to separate a wide variety of useful compounds for several decades. Standard column chromatography consists of a solid stationary phase and a liquid mobile phase, while gas chromatography (GC) uses a solid or liquid stationary phase on a solid support and a gaseous mobile phas... | https://en.wikipedia.org/wiki?curid=30862402 |
Countercurrent chromatography In comparison to column chromatography, flows and total solvent usage can in most countercurrent chromatography separations may be reduced by half and even up to a tenth. Also, the cost of purchasing and disposing of stationary phase media is eliminated. Another advantage of countercurrent... | https://en.wikipedia.org/wiki?curid=30862402 |
Countercurrent chromatography Common factors that influence stationary phase retention are flow rate, solvent composition of the biphasic solvent system, and the g-force. The stationary phase retention is represented by the stationary phase volume retention ratio (Sf) which is the volume of the stationary phase divided... | https://en.wikipedia.org/wiki?curid=30862402 |
Countercurrent chromatography The range is so large, even for a specific instrument, let alone all instrument options, as the type of target, matrix and available biphasic solvent vary so much. Approximately 10 g per liter would be a more typical value, that the majority of applications could use as a base value. The c... | https://en.wikipedia.org/wiki?curid=30862402 |
Countercurrent chromatography However, modern instruments that can accommodate 30 to 70+ % ionic liquids (and potentially 100% ionic liquid, if both phases are suitably customized ionic liquids) have become available. Ionic liquids can be customized for polar / non-polar organic, achiral and chiral compounds, bio-molec... | https://en.wikipedia.org/wiki?curid=30862402 |
Countercurrent chromatography The flow is stopped after the target compound(s) are eluted or the column is extruded by pumping the stationary phase through the column. An example of a major application of countercurrent chromatography is to take an extremely complex matrix such as a plant extract, perform the countercu... | https://en.wikipedia.org/wiki?curid=30862402 |
Countercurrent chromatography DCCC enjoyed some success with natural product separations but was largely eclipsed by the rapid development of high-speed countercurrent chromatography. The main limitation of DCCC is that flow rates are low, and poor mixing is achieved for most binary solvent systems. The modern era of C... | https://en.wikipedia.org/wiki?curid=30862402 |
Countercurrent chromatography Walter Conway & others later evolved the bobbin design such that multiple coils, even coils of different tubing sizes, could be placed on the single bobbin. Edward Chou later evolved and commercialized a triple bobbin design as the Pharmatech CCC which had a de-twist mechanism for leads be... | https://en.wikipedia.org/wiki?curid=30862402 |
Countercurrent chromatography The bobbin is rotated in a double-axis gyratory motion (a cardioid), which causes a variable g-force to act on the column during each rotation. This motion causes the column to see one partitioning step per revolution and components of the sample separate in the column due to their partiti... | https://en.wikipedia.org/wiki?curid=30862402 |
Countercurrent chromatography More recently, in France and UK, non-stacked disc CPC configurations have been developed with PTFE, stainless steel or titanium rotors. These have been designed to overcome possible leakages between the stacked discs of the original concept, and to allow steam cleaning for Good manufacturi... | https://en.wikipedia.org/wiki?curid=30862402 |
Countercurrent chromatography CPC seems particularly suited to accommodate aqueous two-phase solvent systems. Generally, CPC instruments can retain solvent systems that are not well-retained in a hydrodynamic instrument due to small differences in density between the phases. It has been very helpful for the development... | https://en.wikipedia.org/wiki?curid=30862402 |
Countercurrent chromatography Progressively more polar eluents were then used to move polar compounds up the plate. Various alkane bonded phases were tried with C18 becoming the most popular. Alkane chains were chemically bonded to the silica, and a reversal of the elution trend occurred. Thus a polar stationary became... | https://en.wikipedia.org/wiki?curid=30862402 |
Countercurrent chromatography It requires only one column volume of solvent phase and leaves the column full of fresh stationary phase for the subsequent separation. The use of a solvent gradient is very well developed in column chromatography but is less common in CCC. A solvent gradient is produced by increasing (or ... | https://en.wikipedia.org/wiki?curid=30862402 |
Countercurrent chromatography The countercurrent chromatography instrument must be modified so that both ends of the column have both inlet and outlet capabilities. This mode may accommodate continuous or sequential separations with the sample being introduced in the middle of the column or between two bobbins in a hyd... | https://en.wikipedia.org/wiki?curid=30862402 |
Countercurrent chromatography In CCC, the separation characteristics of the column may be modified simply by changing the composition of the biphasic solvent system. In an conventional CCC experiment the biphasic solvent system is pre-equilibrated before the instrument is filled with the stationary phase and equilibrat... | https://en.wikipedia.org/wiki?curid=30862402 |
Countercurrent chromatography It works best with ionizable compounds such as nitrogen containing alkaloids or carboxylic acid containing fatty acids. and related liquid-liquid separation techniques have been used on both industrial and laboratory scale to purify a wide variety of chemical substances. Separation realiza... | https://en.wikipedia.org/wiki?curid=30862402 |
Tin(II) chloride (data page) This page provides supplementary chemical data on tin(II) chloride. Phase behavior Liquid properties Gas properties UV-Vis IR NMR MS Structure and properties The handling of this chemical may incur notable safety precautions. It is highly recommend that you seek the Safety Datasheet (SDS) f... | https://en.wikipedia.org/wiki?curid=30862636 |
Acid attack An Acid Attack, also called acid throwing, vitriol attack, or vitriolage, is a form of violent assault involving the act of throwing acid or a similarly corrosive substance onto the body of another "with the intention to disfigure, maim, torture, or kill". Perpetrators of these attacks throw corrosive liqui... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack The UK has one of the highest rates of acid attacks per capita in the world, according to Acid Survivors Trust International (ASTI). In 2016 there were over 601 acid attacks in the UK based on ASTI figures, and 67% of the victims were male, but statistics from ASTI suggest that 80% of victims worldwide are ... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack " Female students have had acid thrown in their faces as a punishment for attending school. Acid attacks due to religious conflicts have been also reported. Both males and females have been victims of acid attacks for refusing to convert to another religion. Conflicts regarding property issues, land dispute... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack A 2007 literature review analyzed 24 studies in 13 countries over the past 40 years, covering 771 cases. According to the London-based charity Acid Survivors Trust International, 80% of acid attacks are on women, and acid assaults are grossly under-estimated. In some regions, assaults perpetrated on female ... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack High incidence of acid assaults have been reported in some African countries, including Nigeria, Uganda, and South Africa. Unlike occurrences in South Asia, acid attacks in these countries show less gender discrimination. In Uganda, 57% of acid assault victims were female and 43% were male. A study focusing... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack There has recently been a surge in high-profile, public acid attacks in Bulgaria and Greece. In Bangladesh, such attacks are relatively common. Bangladesh has the highest reported incidence of acid assault in the world. According to the Acid Survivors Foundation in Bangladesh, the country has reported 3000 ... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack One study showed that refusal of marriage proposals accounted for 55% of acid assaults, with abuse from a husband or other family member (18%), property disputes (11%) and refusal of sexual or romantic advances (2%) as other leading causes. Additionally, the use of acid attacks in dowry arguments has been r... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack A particularly high-profile case of this nature was the attack on Cambodian teenager Tat Marina in 1999, allegedly carried out by the jealous wife of a government official (the incident prompted a rash of copycat crimes that year, raising the number from seven in 1998 to 40 in 1999). One third of the victim... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack Altogether, from January 2002 to October 2010, 153 cases of acid assault were reported in Indian print media while 174 judicial cases were reported for the year of 2000. The motivation behind acid attacks in India mirrors those in Bangladesh: a study of Indian news reports from January 2002 to October 2010 ... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack The Sharia "code of qisas", or equivalence justice, required a caught perpetrator of acid violence to pay a fine and may be blinded with acid in both eyes. Under Iranian law, victims or their families can ask a court's permission to enact "qisas" either by taking the perpetrator's life in murder cases or af... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack Women who did not conform to these expectations, or to "morality expectations" of secular factions, were vulnerable to attacks which included pouring acid on their bodies, rock pelting, threats, and even rape. B'Tselem has also documented additional attacks with acid in specific attacks involving women in a... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack Moshe Hirsch was the leader of the anti-Zionist Neturei Karta group in Jerusalem. Hirsch had one glass eye due to an injury sustained when someone threw acid in his face. According to his cousin, journalist Abraham Rabinovich, the incident had no link with Hirsch's political activities but was connected to ... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack Acid attacks have been dropped by half in 2019 Acid attacks in Pakistan came to international attention after the release of a documentary by Sharmeen Obaid-Chinoy called "Saving Face" (2012). According to Shahnaz Bukhari, the majority of these attacks occur in the summer when acid is used extensively to so... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack According to the article, the first identified survivor of acid violence in Bogota was attacked in 1998. Since then reported cases have been increasing with time. The study also cited the Colombian Forensics Institute, which reported that 56 women complained of aggression by acid in 2010, 46 in 2011, and 16... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack Three years before the attack took place, Colombia reported one of the highest rates of acid attacks per capita in the world. However, there was not an effective law in place until Ponce de León's campaign took off in the months after her attack. The new law, which is named after her, defines acid attacks a... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack The UK has one of highest rates of acid attacks in the world, according to the police. According to London's Metropolitan Police, 2017 was the worst year for acid attacks in London, with 465 attacks recorded, up from 395 the previous year and 255 in 2015. In 2016, the Metropolitan Police in London recorded ... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack According to data from London's Metropolitan Police, a demographic breakdown of known suspects in London attacks for the period (2002–2016) showed White Europeans comprising 32% of suspects, African Caribbeans 38% and Asian 6%. Victims for the same period were 45% White Europeans, 25% African Caribbeans and... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack On 3 October 2017, the UK government announced that sales of acids to under 18s would be banned. In January 2018, CNN reported that acid attacks in London increased six-fold between 2012 and 2017 and that 71% of attackers and 72% of victims were male. In April 2019, a teenage girl, 13, and a woman, 63, were... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack The most notable effect of an acid attack is the lifelong bodily disfigurement. According to the Acid Survivors Foundation in Pakistan, there is a high survival rate amongst victims of acid attacks. Consequently, the victim is faced with physical challenges, which require long-term surgical treatment, as we... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack Acid assault survivors face many mental health issues upon recovery. One study showed that when compared to published Western norms for psychological well-being, non-Caucasian acid attack victims reported higher levels of anxiety, depression, and scored higher on the Derriford appearance scale, which measur... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack Some media outlets overwhelmingly avoid reporting acid attack violence, or the description of the attack is laconic or often implies that the act was inevitable or even justified. Treatment for burn victims remains inadequate in many developing nations where incidence is high. Medical underfunding has resul... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack Research has prompted many solutions to the increasing incidence of acid attacks in the world. Many countries look to Bangladesh, whose rates of attack have been decreasing, as a model, following their lead in many legislative reforms. However, several reports highlighted the need for an increased, legal ro... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack The Acid Survivors Foundation in Uganda operates in Kampala and provides counseling and rehabilitation treatment to victims, as well as their families. The LICADHO, the Association of the Blind in Cambodia, and the Cambodian Acid Survivors Charity assist survivors of acid attacks. The Acid Survivors Foundat... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack She also spearheads research into social norms of beauty and speaks publicly as an advocate for the empowerment of all victims of disfigurement and discrimination. In 2011, the principal of an Indian college refused to have Juwaley speak at her school for fear that Juwaley's story of being attacked by her h... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack Acid has been used in metallurgy and for etching since ancient times. The rhetorical and theatrical term "La Vitrioleuse" was coined in France after a "wave of vitriolage" occurred according to the popular press where, in 1879, 16 cases of vitriol attacks were widely reported as crimes of passion perpetrate... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack Under the Qisas law of Pakistan, the perpetrator may suffer the same fate as the victim, and may be punished by having drops of acid placed in their eyes. This law is not binding and is rarely enforced according to a report in "The New York Times". In Pakistan, the Lower House of Parliament unanimously pass... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack In 2013, section 326 A of Indian Penal Code was enacted by the Indian Parliament to ensure enhanced punishment for acid throwing. In 2002, Bangladesh introduced the death penalty for acid attacks and laws strictly controlling the sale, use, storage, and international trade of acids. The acids are used in tr... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack The ACA regulates the sale, usage, and storing of acid in Bangladesh through the creation of the National Acid Control Council (NACC). The law requires that the NACC implement policies regarding the trade, misuse, and disposal of acid, while also undertaking initiatives that raise awareness about the danger... | https://en.wikipedia.org/wiki?curid=30862640 |
Acid attack " After a spate of attacks in London in 2017, the Home Office said it would consider changes in laws and measures regarding sales of acid, as well as changes in prosecution and sentencing guidelines. As of 2017, it is unlawful to carry acid with the intent to cause harm. Attacks are prosecuted as acts of ac... | https://en.wikipedia.org/wiki?curid=30862640 |
Gold(III) chloride (data page) This page provides supplementary chemical data on gold(III) chloride The handling of this chemical may incur notable safety precautions. It is highly recommend that you seek the Material Safety Datasheet (MSDS) for this chemical from a reliable source such as SIRI, and follow its directio... | https://en.wikipedia.org/wiki?curid=30862646 |
Pre-exponential factor In chemical kinetics, the pre-exponential factor or A factor is the pre-exponential constant in the Arrhenius equation, an empirical relationship between temperature and rate coefficient. It is usually designated by A when determined from experiment, while Z is usually left for collision frequenc... | https://en.wikipedia.org/wiki?curid=30862748 |
Rotating biological contactor A rotating biological contactor or RBC is a biological treatment process used in the treatment of wastewater following primary treatment. The primary treatment process means protection by removal of grit and sand and coarse material through a screening process, followed by a removal proces... | https://en.wikipedia.org/wiki?curid=30862811 |
Rotating biological contactor The discs contact the wastewater with the atmospheric air for oxidation as it rotates. The rotation helps to slough off excess solids. The disc system can be staged in series to obtain nearly any detention time or degree of removal required. Since the systems are staged, the culture of the... | https://en.wikipedia.org/wiki?curid=30862811 |
Rotating biological contactor The first RBC was installed in West Germany in 1959, later it was introduced in the United States and Canada. In the United States, rotating biological contactors are used for industries producing wastewaters high in biochemical oxygen demand (BOD) (e.g., petroleum industry and dairy indus... | https://en.wikipedia.org/wiki?curid=30862811 |
Rotating biological contactor As a result, the issue of short life failure became fully understood in the early 1990s when the correct process and hydraulic issues had been identified to produce a high quality nitrified effluent. There are several other papers which address the whole issue of RBCs. Findlay also develop... | https://en.wikipedia.org/wiki?curid=30862811 |
Gadolinium gallium garnet Gadolinium Gallium Garnet (GGG, ) is a synthetic crystalline material of the garnet group, with good mechanical, thermal, and optical properties. It is typically colorless. It has a cubic lattice, a density of 7.08 g/cm and its Mohs hardness is variously noted as 6.5 and 7.5. Its crystals are ... | https://en.wikipedia.org/wiki?curid=30862832 |
Aluminium chloride (data page) Supplementary data for aluminium chloride. NIST website Except where noted otherwise, data relate to standard ambient temperature and pressure. | https://en.wikipedia.org/wiki?curid=30862971 |
Temozolomide (TMZ; brand names Temodar and Temodal and Temcad) is an oral chemotherapy drug. It is an alkylating agent used as a treatment of some brain cancers; as a second-line treatment for astrocytoma and a first-line treatment for glioblastoma multiforme. Olaparib in combination with temozolomide demonstrated subs... | https://en.wikipedia.org/wiki?curid=30863182 |
Temozolomide One study indicated that women that have taken temozolomide without concomitant fertility preservation measures achieve pregnancy to a lesser rate later in life, but the study was too small to show statistical significance in the hypothesis that temozolomide would confer a risk of female infertility. In ma... | https://en.wikipedia.org/wiki?curid=30863182 |
Temozolomide However, some tumor cells are able to repair this type of DNA damage, and therefore diminish the therapeutic efficacy of temozolomide, by expressing a protein "O"-alkylguanine DNA alkyltransferase (AGT) encoded in humans by the "O"-6-methylguanine-DNA methyltransferase ("MGMT") gene. In some tumors, epigen... | https://en.wikipedia.org/wiki?curid=30863182 |
Temozolomide It is slightly soluble in water and aqueous acids, and melts at under decomposition. The agent was developed by Malcolm Stevens and his team at Aston University in Birmingham. It has been available in the US since August 1999, and in other countries since the early 2000s. Laboratory studies and clinical tr... | https://en.wikipedia.org/wiki?curid=30863182 |
Temozolomide The resultant novel compound, called NEO212 or TMZ-POH, revealed anticancer activity that was significantly greater than that of either of its two parent molecules, temozolomide and perillyl alcohol. Although , NEO212 has not been tested in humans, it has shown superior cancer therapeutic activity in anima... | https://en.wikipedia.org/wiki?curid=30863182 |
Temozolomide High doses of temozolomide in high-grade gliomas have low toxicity, but the results are comparable to the standard doses. | https://en.wikipedia.org/wiki?curid=30863182 |
Akira Ogata In 1912, Ogata graduated from the Faculty of Medicine of the University of Tokyo. In 1919 he received a degree from the Humboldt University of Berlin, where he had performed pharmacological experiments. In 1920, he was appointed assistant professor at the Faculty of Medicine of the University of Tokyo, wher... | https://en.wikipedia.org/wiki?curid=30864054 |
Akira Ogata The new pill could keep tired pilots more alert and lift the spirits of those in battle. In Japan the drug was used as a workforce pill. It was called ‘Philopon’ which means ‘love of work’. It was given to military personnel as well as government factories. Many pharmaceutical companies in the US patented t... | https://en.wikipedia.org/wiki?curid=30864054 |
TEMPO (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl or (2,2,6,6-tetramethylpiperidin-1-yl)oxidanyl, commonly known as TEMPO, is a chemical compound with the formula (CH)(CMe)NO. This heterocyclic compound is a red-orange, sublimable solid. As a stable aminoxyl radical, it has applications in chemistry and biochemistry. is us... | https://en.wikipedia.org/wiki?curid=30864235 |
TEMPO is employed in organic synthesis as a catalyst for the oxidation of primary alcohols to aldehydes. The actual oxidant is the "N"-oxoammonium salt. In a catalytic cycle with sodium hypochlorite as the stoichiometric oxidant, hypochlorous acid generates the "N"-oxoammonium salt from TEMPO. One typical reaction exam... | https://en.wikipedia.org/wiki?curid=30864235 |
TEMPO Thus, the chemist can control the extent of polymerization and also synthesize narrowly distributed polymer chains. is sufficiently inexpensive for use on a laboratory scale, however at an industrial scale its price is often prohibitive. Structurally related analogues do exist, which are largely based on 4-hydrox... | https://en.wikipedia.org/wiki?curid=30864235 |
Jacob Israelachvili Jacob Nissim Israelachvili (19 August 1944 – 20 September 2018) was an Israeli physicist and chemical engineer who was a professor of chemical engineering at the University of California, Santa Barbara (UCSB). He was born in Tel Aviv, Israel and sent to an English boarding school at the age of 7. Af... | https://en.wikipedia.org/wiki?curid=30864881 |
Jacob Israelachvili Currently, he is studying interfacial phenomena, the physics of thin films, and fundamental questions in rheology and tribology of surfaces. Israelachvili has developed numerous techniques for the static and dynamic measurement of material and molecular properties of vapors, liquids, and surfaces. I... | https://en.wikipedia.org/wiki?curid=30864881 |
Jacob Israelachvili Israelachvili was also founder of SurForce, LLC. The company specializes in researching surface force interactions and producing SFA systems. | https://en.wikipedia.org/wiki?curid=30864881 |
Water quality modelling Water quality modeling involves the prediction of water pollution using mathematical simulation techniques. A typical water quality model consists of a collection of formulations representing physical mechanisms that determine position and momentum of pollutants in a water body. Models are avail... | https://en.wikipedia.org/wiki?curid=30865207 |
Complementarity (molecular biology) In molecular biology, complementarity describes a relationship between two structures each following the lock-and-key principle. In nature complementarity is the base principle of DNA replication and transcription as it is a property shared between two DNA or RNA sequences, such that... | https://en.wikipedia.org/wiki?curid=30865488 |
Complementarity (molecular biology) Complementarity is achieved by distinct interactions between nucleobases: adenine, thymine (uracil in RNA), guanine and cytosine. Adenine and guanine are purines, while thymine, cytosine and uracil are pyrimidines. Purines are larger than pyrimidines. Both types of molecules compleme... | https://en.wikipedia.org/wiki?curid=30865488 |
Complementarity (molecular biology) DNA repair mechanisms such as proof reading are complementarity based and allow for error correction during DNA replication by removing mismatched nucleobases. Nucleic acids strands may also form hybrids in which single stranded DNA may readily anneal with complementary DNA or RNA. T... | https://en.wikipedia.org/wiki?curid=30865488 |
Complementarity (molecular biology) Genome wide studies have shown that RNA antisense transcripts occur commonly within nature. They are generally believed to increase the coding potential of the genetic code and add an overall layer of complexity to gene regulation. So far, it is known that 40% of the human genome is ... | https://en.wikipedia.org/wiki?curid=30865488 |
Complementarity (molecular biology) And three is by providing a new double-stranded RNA (dsRNA) sequence that Dicer can act upon to create more miRNA to find and degrade more copies of the gene. Small interfering RNAs (siRNAs) are similar in function to miRNAs; they come from other sources of RNA, but serve a similar p... | https://en.wikipedia.org/wiki?curid=30865488 |
Complementarity (molecular biology) Too strong an initial binding to a bad location and the strands will not unwind quickly enough; too weak an initial binding and the strands will never fully form the desired complex. These hairpin structures allow for the exposure of enough bases to provide a strong enough check on t... | https://en.wikipedia.org/wiki?curid=30865488 |
Complementarity (molecular biology) When writing sequences for systematic biology it may be necessary to have IUPAC codes that mean "any of the two" or "any of the three". The IUPAC code R (any purine) is complementary to Y (any pyrimidine) and M (amino) to K (keto). W (weak) and S (strong) are usually not swapped but ... | https://en.wikipedia.org/wiki?curid=30865488 |
Teclu burner The is a laboratory gas burner, a variant of the Bunsen burner, named after the Romanian chemist Nicolae Teclu. It can produce a hotter flame than a Bunsen burner. The lower part of its tube is conical, with a round screw nut below its base. The gap, set by the distance between the nut and the end of the t... | https://en.wikipedia.org/wiki?curid=30868647 |
Surface plasmon polariton Surface plasmon polaritons (SPPs) are electromagnetic waves that travel along a metal–dielectric or metal–air interface, practically in the infrared or visible-frequency. The term "surface plasmon polariton" explains that the wave involves both charge motion in the metal ("surface plasmon") an... | https://en.wikipedia.org/wiki?curid=30868906 |
Surface plasmon polariton The component of the scattering vector parallel to the surface results in the formation of a surface plasmon polariton. For a photon to excite an SPP, both must have the same frequency and momentum. However, for a given frequency, a free-space photon has "more" momentum than an SPP because the... | https://en.wikipedia.org/wiki?curid=30868906 |
Surface plasmon polariton The properties of an SPP can be derived from Maxwell's equations. We use a coordinate system where the metal–dielectric interface is the formula_1 plane, with the metal at formula_2 and dielectric at formula_3. The electric and magnetic fields as a function of position formula_4 and time "t" a... | https://en.wikipedia.org/wiki?curid=30868906 |
Surface plasmon polariton The surface plasma frequency is the asymptote of this curve, and is given by In the case of air, this result simplifies to If we assume that "ε" is real and "ε" > 0, then it must be true that "ε" < 0, a condition which is satisfied in metals. Electromagnetic waves passing through a metal exper... | https://en.wikipedia.org/wiki?curid=30868906 |
Surface plasmon polariton In the dielectric, the field will fall off far more slowly. The decay lengths in the metal and dielectric medium can be expressed as where formula_32 is the polarization angle and formula_33 is the angle from the "z"-axis in the "xz"-plane. Two important consequences come out of these equation... | https://en.wikipedia.org/wiki?curid=30868906 |
Plasmonic metamaterial A plasmonic metamaterial is a metamaterial that uses surface plasmons to achieve optical properties not seen in nature. Plasmons are produced from the interaction of light with metal-dielectric materials. Under specific conditions, the incident light couples with the surface plasmons to create se... | https://en.wikipedia.org/wiki?curid=30869356 |
Plasmonic metamaterial In negative index materials energy is transported in a direction opposite to that of propagating wavefronts, rather than paralleling them, as is the case in positive index materials. Normally, light traveling from, say, air into water bends upon passing through the normal (a plane perpendicular t... | https://en.wikipedia.org/wiki?curid=30869356 |
Plasmonic metamaterial Light falling on conventional materials, with a positive index of refraction, exerts a positive pressure, meaning that it can push an object away from the light source. In contrast, illuminating negative index metamaterials should generate a negative pressure that pulls an object toward light. Co... | https://en.wikipedia.org/wiki?curid=30869356 |
Plasmonic metamaterial These specific properties are also highly required to fabricate integrated optical meta-circuits for the quantum information applications. The first metamaterials created exhibit anisotropy in their effects on plasmons. I.e., they act only in one direction. More recently, researchers used a novel... | https://en.wikipedia.org/wiki?curid=30869356 |
Plasmonic metamaterial Potential applications of graphene plasmonics involve terahertz to midinfrared frequencies, in devices such as optical modulators, photodetectors and biosensors. A hyperbolic metamaterial made from titanium nitride (metal) and aluminum scandium nitride (dielectric) have compatible crystal structu... | https://en.wikipedia.org/wiki?curid=30869356 |
Plasmonic metamaterial Gradient index plasmonics were used to produce Luneburg and Eaton lenses that interact with surface plasmon polaritons rather than photons. A theorized superlens could exceed the diffraction limit that prevents standard (positive-index) lenses from resolving objects smaller than one-half of the w... | https://en.wikipedia.org/wiki?curid=30869356 |
Plasmonic metamaterial The switch is made of a metamaterial consisting of nanoscale particles of vanadium dioxide (), a crystal that switches between an opaque, metallic phase and a transparent, semiconducting phase. The nanoparticles are deposited on a glass substrate and overlain by even smaller gold nanoparticles th... | https://en.wikipedia.org/wiki?curid=30869356 |
Glazing (window) Glazing, which derives from the Middle English for 'glass', is a part of a wall or window, made of glass. Glazing also describes the work done by a professional "glazier". Glazing is also less commonly used to describe the insertion of ophthalmic lenses into an eyeglass frame. Common types of glazing t... | https://en.wikipedia.org/wiki?curid=30871229 |
Curie's law In a paramagnetic material, the magnetization of the material is (approximately) directly proportional to an applied magnetic field. However, if the material is heated, this proportionality is reduced: for a fixed value of the field, the magnetization is (approximately) inversely proportional to temperature... | https://en.wikipedia.org/wiki?curid=30872301 |
Curie's law In other words, one seeks the expectation value of the magnetization formula_8: where the probability of a configuration is given by its Boltzmann factor, and the partition function formula_14 provides the necessary normalization for probabilities (so that the sum of all of them is unity.) The partition fun... | https://en.wikipedia.org/wiki?curid=30872301 |
Curie's law Using the Fermi-Dirac distribution, one will find that at low temperatures formula_25 is linear dependent on the magnetic field, so that the magnetic susceptibility saturates to a constant. When the particles have an arbitrary spin (any number of spin states), the formula is a bit more complicated. At low m... | https://en.wikipedia.org/wiki?curid=30872301 |
Curie's law ) The corresponding partition function is We see there is no dependence on the formula_36 angle, and also we can change variables to formula_37 to obtain Now, the expected value of the formula_34 component of the magnetization (the other two are seen to be null (due to integration over formula_36), as they ... | https://en.wikipedia.org/wiki?curid=30872301 |
Hypoxia (environmental) Hypoxia refers to low oxygen conditions. Normally, 20.9% of the gas in the atmosphere is oxygen. The partial pressure of oxygen in the atmosphere is 20.9% of the total barometric pressure. In water, oxygen levels are much lower, approximately 7 ppm 0.0007% in good quality water, and fluctuate lo... | https://en.wikipedia.org/wiki?curid=30872597 |
Hypoxia (environmental) Dissolved oxygen is typically expressed as a percentage of the oxygen that would dissolve in the water at the prevailing temperature and salinity (both of which affect the solubility of oxygen in water; see oxygen saturation and underwater). An aquatic system lacking dissolved oxygen (0% saturat... | https://en.wikipedia.org/wiki?curid=30872597 |
Hypoxia (environmental) While phytoplankton, through photosynthesis, will raise DO saturation during daylight hours, the dense population of a bloom reduces DO saturation during the night by respiration. When phytoplankton cells die, they sink towards the bottom and are decomposed by bacteria, a process that further re... | https://en.wikipedia.org/wiki?curid=30872597 |
Hypoxia (environmental) Scientists have determined that high concentrations of minerals dumped into bodies of water causes significant growth of phytoplankton blooms. As these blooms are broken down by bacteria, such as "Phanerochaete chrysosprium", oxygen is depleted by the enzymes of these organisms. Phytoplankton ar... | https://en.wikipedia.org/wiki?curid=30872597 |
Hypoxia (environmental) Oxyferroheme and veratric alcohol combine to create oxygen radical and Ferri-LiP, which can now be used to degrade lignin. Oxygen radicals cannot be used in the environment, and are harmful in high presence in the environment. Once Ferri-LiP is present in the ligninperoxidase, it can be used to ... | https://en.wikipedia.org/wiki?curid=30872597 |
Hypoxia (environmental) This is energetically favorable due to its negative free energy requirements, and therefore this reaction catalyzed by LiP is likely to take place spontaneously. Breakdown of propanol and phenols occur naturally in the environment because they are both water-soluble. The breakdown of phytoplankt... | https://en.wikipedia.org/wiki?curid=30872597 |
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