For years, the struggle among the Arabian Gulf countries has centrally focused on the region's stabilities and which players to back.
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That will proof that we are really solid, strong and able to meet our credibility in managing all the prudential side, financial stabilities and our monetary policies.
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"I want to continue to play a key role in advancing policies that ... bring peace and stabilities to a troubled and violent world," Collins said in an announcement Friday.
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Students on the scholarship would have to attend school full time unless they have stabilities, and though their tuition would be free, they'd still have to pay for books, fees, and room and board if they live on campus.
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Carbocation and carbanion stabilities can be assessed using hydride ion affinities and pKa values, respectively.
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For these blends to be successful in reducing heat duty, their chemical stabilities must be maintained.
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Stevens, R; Stevens, L; Price, N. C (1983) The Stabilities of Various Thiol Compounds used in Protein Purifications. Biochemical Education, 11 (2), 70.
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The stabilities of the alkali-ion pairs as function of the anion charge z by can be described by a more detailed equation.
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Biochemical and biophysical studies revealed that VIM variants have only small variations in their kinetic parameters but substantial differences in their thermal stabilities and inhibition profiles.
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Sharkey, J. B.; Lewin, S. Z. Thermochemical properties of the copper (II) hydroxychlorides. Thermochimica Acta 1972, 3(3), 189.Pollard, A. M.; Thomas, R. G.; Williams, P. A. Synthesis and stabilities of the basic copper (II) chlorides atacamite, paratacamite, and botallackite. Mineral Mag.
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For example, the dipeptide Ala-Gln has the solubility of 586 g/L more than 10x the solubility of Gln (35 g/L). Dipeptides also can exhibit different stabilities, e.g. with respect to hydrolysis. Gln does not withstand, sterilization procedures, whereas this dipeptide does.
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A fixed wing is typically unstable in pitch, roll, and yaw. Pitch and yaw stabilities of conventional fixed wing designs require horizontal and vertical stabilisers,Crane, Dale: Dictionary of Aeronautical Terms, third edition, p. 194. Aviation Supplies & Academics, 1997. Aviation Publishers Co. Limited, From the Ground Up, p.
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JHU37160 and JHU37152 have been marketed commercially as novel DREADD ligands, active in vivo, with high potency and affinity for hM3Dq and hM4Di DREADDs. Diihydrochloride salts of DREADDs ligands that are water-soluble (but with differing stabilities in solution) have also been commercially developed (see for aqueous stability).
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Other common coordination geometries are tetrahedral and square planar. Crystal field theory may be used to explain the relative stabilities of transition metal compounds of different coordination geometry, as well as the presence or absence of paramagnetism, whereas VSEPR may be used for complexes of main group element to predict geometry.
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The structural domain, cCTnC, exists as a "molten globule" in the apo state, but forms a well structured open conformation in the Ca2+-bound state. These structural differences change the relative stabilities of the apo- and Ca2+-bound states, accounting for the divergent Ca2+-binding affinities between the two domains.
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These additional components in parenteral nutritions, however were subject to stability checks, since they greatly affect the stability of lipid emulsions that serve as the base for these formulations. Studies have shown differences in physical and chemical stabilities of these total parenteral nutrition solutions, which greatly influences pharmaceutical manufacturing of these admixtures.
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Different mRNAs within the same cell have distinct lifetimes (stabilities). In bacterial cells, individual mRNAs can survive from seconds to more than an hour. However, the lifetime averages between 1 and 3 minutes, making bacterial mRNA much less stable than eukaryotic mRNA. In mammalian cells, mRNA lifetimes range from several minutes to days.
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Rotational arrangements relate to the non-planar confirmation as compared to the ideal coplanar geometry. Intra-base pair parameters are used to determine the structure and stabilities of non-canonical base pairs. These parameters were originally created for the base pairings in DNA but can also fit the non-canonical base models.
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Exchange rates usually follow the trend I > Br > Cl. Alkyl- and arylfluoride are generally unreactive toward organolithium reagents. Lithium halogen exchange is kinetically controlled, and the rate of exchange is primarily influenced by the stabilities of the carbanion intermediates (sp > sp2 > sp3) of the organolithium reagents.The Preparation of Organolithium Reagents and Intermediates Leroux.F., Schlosser.
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If the chalk was rejected, then the Oba would try to invade Esanland. The varying political stabilities of Benin and the Esan kingdoms also led to warfare. Such warfare was so common that there is no recorded history of peace between all of the Esan kingdoms and Benin. Esanland was extensively involved in world trade.
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She has worked on charge-transfer complexes and how charge is transferred between electron donors (such as NH3, C2H4) and electron acceptors (F2, Cl2). She studied 2D electrides, alkalides and transition-metal diatomics. In 2017, she collaborated with Kim Jelfs to predict the relative stabilities of polymorphs of aza-6-helicene from first principles.
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In 2000 Fleming started her research laboratory at Johns Hopkins University. She continued to study the interactions of transmembrane helices, as well as investigating beta barrels. Her work on beta barrels allowed her research group to significantly increase the number of known membrane protein stabilities. She created a hydrophobicity scale to describe protein side-chains.
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These species are all very unstable and are observed as fleeting intermediates in the gas phase. At a few millibars pressure, the relative stabilities are S2O > S2O2 > SO. Sulfur monoxide (SO) and its dimer (S2O2) have been trapped at low temperature. Disulfur dioxide (S2O2) is a dimer of sulfur monoxide. It has C2v structure (planar).
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Like thallium, moscovium should have a common +1 oxidation state and a less common +3 oxidation state, although their relative stabilities may change depending on the complexing ligands or the degree of hydrolysis. Moscovium(I) oxide (Mc2O) should be quite basic, like that of thallium, while moscovium(III) oxide (Mc2O3) should be amphoteric, like that of bismuth.
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2003, 32, pp 276-288. COFs are another class of porous polymeric materials, consisting of porous, crystalline, covalent bonds that usually have rigid structures, exceptional thermal stabilities (to temperatures up to 600 °C), are stable in water and low densities. They exhibit permanent porosity with specific surface areas surpassing those of well-known zeolites and porous silicates.
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Organic ladder polymers are interest because they can exhibit exceptional thermal stabilities and the conformation of the subunits is constrained. Because they are less flexible, their processing can be challenging. An early example was derived from condensation of the 1,2,4,5-tetraaminobenzene with naphthalenetetracarboxylic dianhydride.Scherf, Ullrich "Ladder-type materials" Journal of Materials Chemistry 1999, volume 9, 1853-1864.
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Ryan is an expert in electrochemistry and interfacial material science. Ryan joined Imperial College London as a lecturer in 1998. Her research group explore the mechanism of corrosion, new protective materials and materials with thermal management capabilities. She studies the process of electrochemical deposition, the stabilities of metals and the formation processes of metal and oxide nanostructures.
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This mechanism also proceeds with inversion at the carbon center. This reaction is known to be reversible. Depending on the relative stabilities of the carbanion and oxy-anion formed, a silyl ether is perfectly capable of rearranging to a species with the silicon bonded to the carbon atom, and the free alcohol being present. This would be termed a Retro-Brook rearrangement.
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It is possible to predict the results of a halogenation reaction based on bond dissociation energies and the relative stabilities of the radical intermediates. Another factor to consider is the probability of reaction at each carbon atom, from a statistical point of view. Due to the different dipole moments of the product mixture, it may be possible to separate them by distillation.
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The AFIT instrument quantifies the dynamic foaming properties of air entraining agents, surfactants and foaming materials. It makes these measurements without intrusion of a probe or device into a working environment. Appropriate foam stabilities are necessary for proper performance of the materials onto/into which AEA’s or surfactants are applied. Stable foams have stable bubbles; unstable foams have breaking bubbles.
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The Irving–Williams series refers to high-spin, octahedral, divalent metal ion of the first transition series. It places the stabilities of complexes in the order :Mn < Fe < Co < Ni < Cu > Zn This order was found to hold for a wide variety of ligands. There are three strands to the explanation of the series. #The ionic radius is expected to decrease regularly for Mn2+ to Zn2+.
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Organometallic Complexes for Optoelectronic Applications. Thompson, M.E.; Djurovich, P.E.; Barlow, S.; Marder, S., Comprehensive Organometallic Chemistry III, 2007, 12, 101-194. His laboratory discovered and developed a class of Ir(III)-based complexes featuring polyaromatic ligands, which can be efficiently tuned for color emission and excited-state lifetimes. These materials can be doped in the emissive layer of multilayer, vapor- deposited OLEDs and generally show high stabilities and efficiencies.
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For an overview of major minerals in siliciclastic rocks and their relative stabilities, see Folk (1965), pp. 62–64. The amount of weathering depends mainly on the distance to the source area, the local climate and the time it took for the sediment to be transported to the point where it is deposited. In most sedimentary rocks, mica, feldspar and less stable minerals have been reduced to clay minerals like kaolinite, illite or smectite.
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Secondly, despite its recent internal stabilities, the country is suffering from ongoing conflicts in adjacent countries. Djibouti has seen a considerable number of refugees and asylum seekers fleeing to the country from Eritrea, Ethiopia, Somalia and Yemen. As of March 2018, the number of refugees and asylum-seekers amounts to 27 000 people. Moreover, the implementation of such strategy also depends on the political leadership and its willingness to commit to the programs.
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Line trip is one of the general disturbances in the power system. The outage of transmission lines affects the frequency and voltage stabilities of the system. By utilizing the measurement data in FNET system, the line trip events can be detected correctly and efficiently. The current project primarily focuses on the design of a professional line trip adaptor to realize the online line trip detection and to provide automatic alert notification for the clients.
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The results suggested that the rank-order stabilities of facets were high, with values greater than .50 (indicating a strong correlation); the results for trait domains were similar to individual facets. High rank-order stability is further evidenced by another study that integrated personality structure, process, and development. This study included previous research that indicated high-order rank stability; it also included research that indicated variation in this stability across periods of the lifespan, such as adolescence and adulthood.
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Hooge, D. M.; Steward, F. A.; McNaughton, J. L. "Improved Stabilities of Vitamins A, D3, E and Riboflavin with Tribasic Copper Chloride (TBCC) Compared to Copper Sulfate Pentahydrate in Crumbled Broiler Starter Feed". Paper presented at the 89th Annual Meeting of the Poultry Science Association, Palais de Congress, Montreal, Quebec, Canada, August 19, 2000.O’Keefe, S. F.; Steward, F. A. “Food Stability – a Mineral’s Chemical Form Dictates How Actively It Promotes Oxidation”. Petfood Industry, May/June, 1999, 46-50.
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The internal angles of a flat regular hexagon are 120°, while the preferred angle between successive bonds in a carbon chain is about 109.5°, the tetrahedral angle. Therefore, the cyclohexane ring tends to assume certain non-planar (warped) conformations, which have all angles closer to 109.5° and therefore a lower strain energy than the flat hexagonal shape. The most important shapes are chair, half- chair, boat, and twist-boat. Their relative stabilities are: chair > twist boat > boat > half-chair.
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When a reactant can form two different products depending on the reaction conditions, it becomes important to choose the right conditions to favor the desired product. If a reaction is carried out at relatively lower temperature, then the product formed is one lying across the smaller energy barrier. This is called kinetic control and the ratio of the products formed depends on the relative energy barriers leading to the products. Relative stabilities of the products do not matter.
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According to Gibbs' rules of phase equilibria, these unique crystalline phases are dependent on intensive variables such as pressure and temperature. Polymorphism is related to allotropy, which refers to elemental solids. The complete morphology of a material is described by polymorphism and other variables such as crystal habit, amorphous fraction or crystallographic defects. Polymorphs have different stabilities and may spontaneously and irreversibly transform from a metastable form (or thermodynamically unstable form) to the stable form at a particular temperature.
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This state represents a combination of folded hydrophobic α-helices and partially unfolded segments covered by the detergent. For example, the "unfolded" bacteriorhodopsin in SDS micelles has four transmembrane α-helices folded, while the rest of the protein is situated at the micelle-water interface and can adopt different types of non-native amphiphilic structures. Free energy differences between such detergent-denatured and native states are similar to stabilities of water-soluble proteins (< 10 kcal/mol).
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When higher stabilities are required, the crystals and their driving circuits may be mounted in a "crystal oven" to control the temperature. For very narrow band filters, sometimes several crystals are operated in series. A large number of crystals can be collapsed into a single component, by mounting comb-shaped evaporations of metal on a quartz crystal. In this scheme, a "tapped delay line" reinforces the desired frequencies as the sound waves flow across the surface of the quartz crystal.
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The "strain energy" of a molecule is a quantity that is difficult to precisely define, so the meaning of this term can easily vary depending on one's interpretation. Instead, an objective way to view the allylic strain of a molecule is through its conformational equilibrium. Comparing the heats of formation of the involved conformers, an overall ΔHeq can be evaluated. This term gives information about the relative stabilities of the involved conformers and the effect allylic strain has on equilibrium.
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By being able to allocate flexible (virtual) CPUs to each of the VNFC instances, the network management layer can scale up (i.e., scale vertically) the VNFC to provide the throughput/performance and scalability expectations over a single system or a single platform. Similarly, the network management layer can scale out (i.e., scale horizontally) a VNFC by activating multiple instances of such VNFC over multiple platforms and therefore reach out to the performance and architecture specifications whilst not compromising the other VNFC function stabilities.
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If the chalk was rejected, then the Oba would try to invade Esanland. The varying political stabilities of Benin and the Esan kingdoms also led to warfare. Such warfare was so common that there is no recorded history of peace between all of the Esan kingdoms and Benin. Esanland was extensively involved in world trade. Benin’s sovereignty over Esanland enabled it to send long-distant traders, or Ekhen procured cloth, ivory, peppers, and slaves for European merchants in Yorubaland, Esanland, and Afenmai.
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An ion chromatography system used to detect and measure cations such as sodium, ammonium and potassium in Expectorant Cough Formulations. There has been a growing interest in the application of IC in the analysis of pharmaceutical drugs. IC is used in different aspects of product development and quality control testing. For example, IC is used to improve stabilities and solubility properties of pharmaceutical active drugs molecules as well as used to detect systems that have higher tolerance for organic solvents.
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For psychotherapy, counseling, and coaching, the question of stability – or over- stability – as well as change and new adaptation is essential. The model for understanding these phenomena is the interdisciplinary systems theory of synergetics, which in turn derives from the theory of non-linear dynamic systems. It deals with self-organization processes in which a large number of components form orders or patterns which then react upon the further developmental dynamics of the components. Such dynamic stabilities or orders are called attractors.
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The polymers obtained from captodatively substituted starting materials exhibit "desirable" properties such as optical activity, differences in polarity, solvent affinity, thermal and mechanical stabilities. Substituents on the monomer can affect solvent affinities How a captodative monomer can form a polar polymer # Polymers with polar substituents are known to have interesting applications including within electrical and optical materials. # These polymers are typically transparent. # The Tdi (initial decomposition) of these polymers are relatively low compared to their analogues, but have relatively higher Tdm (maximum rate of weight change temperatures).
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This enabled him to establish an order of the relative stabilities of metal–organic complexes along the latter half of the transition series manganese through zinc. From these findings he saw a parallel with the selective uptake of metal ions by organisms. Williams’s plan was to continue working with Irving for his DPhil, but he first visited the lab of Arne Tiselius at Uppsala University. He was impressed by what he saw there, and returned to Sweden after he gained his DPhil in 1950.
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They are also the best for other races and for the same reasons. The energy required at these wavelengths is least and the necessary stabilities and collecting areas are fundamentally easier to realize and cheaper than at shorter wavelengths. Microwave window as seen by a ground-based system. From NASA report SP-419: SETI - the Search for Extraterrestrial Intelligence 4\. The best part of the microwave region is the low frequency end of the "microwave window"- frequencies from about 1 to 2 or 3 GHz.
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In 1951 the US Army Chemical Corps and Ordnance Corps initiated a joint program to develop a 115mm chemical rocket. The US Army Ordnance Corps designed the 115mm T238 and launcher in 1957 to provide the army a means to attack large area targets with chemical agents. Artillery and mortars are for small area targets; and due to different spin stabilities, warheads intended for explosives are not ideal for chemical delivery. The 115mm rocket was subsequently accepted as the M55 rocket with M91 launcher.
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A variety of reagents have been used to dope PTs. Iodine and bromine produce highly conductive materials, which are unstable owing to slow evaporation of the halogen. Organic acids, including trifluoroacetic acid, propionic acid, and sulfonic acids produce PTs with lower conductivities than iodine, but with higher environmental stabilities. Oxidative polymerization with ferric chloride can result in doping by residual catalyst, although matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) studies have shown that poly(3-hexylthiophene)s are also partially halogenated by the residual oxidizing agent.
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CFSE for Zn(II) is zero. #Although the CFSE of Cu(II) is less than that of Ni(II), octahedral Cu(II) complexes are subject to the Jahn–Teller effect, which affords octahedral Cu(II) complexes additional stability. However, none of the above explanations can satisfactorily explain the success of the Irving–Williams series in predicting the relative stabilities of transition metal complexes. A recent study of metal-thiolate complexes indicates that an interplay between covalent and electrostatic contributions in metal–ligand binding energies might result in Irving–Williams series.
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Energy diagrams of SN1 reactions Hammond's postulate can be used to examine the structure of the transition states of a SN1 reaction. In particular, the dissociation of the leaving group is the first transition state in a SN1 reaction. The stabilities of the carbocations formed by this dissociation are known to follow the trend tertiary > secondary > primary > methyl. Therefore, since the tertiary carbocation is relatively stable and therefore close in energy to the R-X reactant, then the tertiary transition state will have a structure that is fairly similar to the R-X reactant.
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Primary functions are to supply information about structures, relative stabilities and other properties of isolated molecules. Molecular mechanics calculations on complex molecules are common in the chemical community. Quantum chemical calculations, including Hartree–Fock method molecular orbital calculations, but especially calculations that include electronic correlation, are more time-consuming in comparison. Quantum chemical calculations are also called upon to furnish information about mechanisms and product distributions of chemical reactions, either directly by calculations on transition states, or based on Hammond's postulate, by modeling the steric and electronic demands of the reactants.
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Energy diagrams of SN1 reactions Hammond's postulate can be used to examine the structure of the transition states of a SN1 reaction. In particular, the dissociation of the leaving group is the first transition state in a SN1 reaction. The stabilities of the carbocations formed by this dissociation are known to follow the trend tertiary > secondary > primary > methyl. Therefore, since the tertiary carbocation is relatively stable and therefore close in energy to the R-X reactant, then the tertiary transition state will have a structure that is fairly similar to the R-X reactant.
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The C-rich stability element is a short part of a gene sequence important for the proper synthesis of globin and several other human proteins. Differences in the stabilities of individual mRNAs can dramatically affect the overall level of expression for genes. Eukaryotic mRNAs can have half-lives that vary from as short as several minutes to as long as several days. In differentiating human erythroid cells the deposition of high levels of alpha globin protein is dependent on an unusually long half-life of the alpha globin mRNA (greater than 24hrs).
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Perfect authentic cadence (IV–V–I chord progression, in which we see the chords F major, G major, and then C major, in four-part harmony) in C major. thumb "Tonal music is built around these tonic and dominant arrival points [cadences], and they form one of the fundamental building blocks of musical structure" . Tonality is the arrangement of pitches and/or chords of a musical work in a hierarchy of perceived relations, stabilities, attractions and directionality. In this hierarchy, the single pitch or triadic chord with the greatest stability is called the tonic.
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This determination entails speeding up the oxidation process in the oil (under heat and forced air), which enables its stability to be evaluated by monitoring volatile substances associated with rancidity. It is measured as "induction time" and recorded as total hours before the oil breaks down. Canola oil requires 7.5 hours, for example, whereas extra virgin olive oil (EVOO) and virgin coconut oil will last over a day at 110 °C of continuous heat. The differing stabilities correlate with lower levels of polyunsaturated fatty acids, which are more prone to oxidation.
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Microbiologically induced calcium carbonate precipitation (MICP) is a bio- geochemical process that induces calcium carbonate precipitation within the soil matrix. Biomineralization in the form of calcium carbonate precipitation can be traced back to the Precambrian period. Calcium carbonate can be precipitated in three polymorphic forms, which in the order of their usual stabilities are calcite, aragonite and vaterite. The main groups of microorganisms that can induce the carbonate precipitation are photosynthetic microorganisms such as cyanobacteria and microalgae; sulfate-reducing bacteria; and some species of microorganisms involved in nitrogen cycle.
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A nuclear run-on assay is conducted to identify the genes that are being transcribed at a certain time point. Approximately one million cell nuclei are isolated and incubated with labeled nucleotides, and genes in the process of being transcribed are detected by hybridization of extracted RNA to gene specific probes on a blot. Garcia-Martinez et al. (2004) developed a protocol for the yeast S. cerevisiae (Genomic run-on, GRO) that allows for the calculation of transcription rates (TRs) for all yeast genes to estimate mRNA stabilities for all yeast mRNAs.
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Phase diagram of sulfur showing the relative stabilities of several allotropes STP Phase diagram for solid oxygen Oxygen's most common allotrope is diatomic oxygen, or O2, a reactive paramagnetic molecule that is ubiquitous to aerobic organisms and has a blue color in its liquid state. Another allotrope is O3, or ozone, which is three oxygen atoms bonded together in a bent formation. There is also an allotrope called tetraoxygen, or O4, and six allotropes of solid oxygen including "red oxygen", which has the formula O8. Sulfur has over 20 known allotropes, which is more than any other element except carbon.
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Despite the potential separation of actinides, a direct extraction from the PUREX raffinate is very hard, due to the presence of many other interfering species in the feed such as activation and fission products. In this perspective, advanced separation processes involving very selective extracting agents are required to achieve an efficient partitioning for the following transmutation process. To sum up, knowledge of hydration, acid-base interactions, kinetics and thermodynamic stabilities and speciation of actinide and lanthanide ions with ligands is of great value to understand a solvent extraction process and to design new and promising extracting agents.
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Reflecting their high stabilities, thiophenes arise from many reactions involving sulfur sources and hydrocarbons, especially unsaturated ones. The first synthesis of thiophene by Meyer, reported the same year that he made his discovery, involves acetylene and elemental sulfur. Thiophenes are classically prepared by the reaction of 1,4-diketones, diesters, or dicarboxylates with sulfidizing reagents such as P4S10 such as in the Paal-Knorr thiophene synthesis. Specialized thiophenes can be synthesized similarly using Lawesson's reagent as the sulfidizing agent, or via the Gewald reaction, which involves the condensation of two esters in the presence of elemental sulfur.
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In addition to these exceptional stabilities, the nanomesh shows the extraordinary ability to act as a scaffold for metallic nanoclusters and to trap molecules forming a well-ordered array. In the case of gold (Au), its evaporation on the nanomesh leads to formation of well-defined round Au nanoparticles, which are centered at the nanomesh pores. The STM figure on the right shows Naphthalocyanine (Nc) molecules, which were vapor-deposited onto the nanomesh. These planar molecules have a diameter of about 2 nm, whose size is comparable to that of the nanomesh pores (see upper inset).
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Perovskite are mixed metal oxide with a well-defined cubic structure and a general formula of ABO3, where A is an alkaline earth or lanthanide element and B is a transition metal. These materials are attractive for CO2 separation because of the tunability of the metal sites as well as their stabilities at elevated temperatures. The separation of CO2 from N2 was investigated with an α-alumina membrane impregnated with BaTiO3. It was found that adsorption of CO2 was favorable at high temperatures due to an endothermic interaction between CO2 and the material, promoting mobile CO2 that enhanced CO2 adsorption-desorption rate and surface diffusion.
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Zirconium(II) hydride, ZrH2 is a molecular chemical compound which has been prepared by laser ablation and isolated at low temperature. Zirconium(II) hydride has repeatedly been the subject of Dirac–Hartree–Fock relativistic calculation studies, which investigate the stabilities, geometries, and relative energies of hydrides of the formula MH4, MH3, MH2, or MH. Zirconium(II) hydride has a dihedral (C2v) structure. In zirconium(II) hydride, the formal oxidation states of hydrogen and zirconium are −1 and +2, respectively, because the electronegativity of zirconium is lower than that of hydrogen. The stability of metal hydrides with the formula MH2 (M = Ti-Hf) decreases as the atomic number increases.
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He discussed the conditions needed for the generation of mesoporous materials, such as inverse milcelles, elimination of solvent effects and the controlled condensation of inorganic frameworks. According to Suib, manipulating the nanoparticle size can tune the mesopores and this phenomena can lead to the development of multiple phases of the same metal oxide and can also aid in the synthesis of materials having different structures and thermal stabilities. For developing high surface area metal titanates, Suib proposed a generalized synthesis method involving a metal dissolution and reverse micelle formation. His research group produced the highest surface areas of such metals and used SEM-EDX and TEM mapping for the study of homogeneous distributions of the metals.
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Physical organic chemistry, a term coined by Louis Hammett in 1940, refers to a discipline of organic chemistry that focuses on the relationship between chemical structures and reactivity, in particular, applying experimental tools of physical chemistry to the study of organic molecules. Specific focal points of study include the rates of organic reactions, the relative chemical stabilities of the starting materials, reactive intermediates, transition states, and products of chemical reactions, and non-covalent aspects of solvation and molecular interactions that influence chemical reactivity. Such studies provide theoretical and practical frameworks to understand how changes in structure in solution or solid-state contexts impact reaction mechanism and rate for each organic reaction of interest.
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Physical organic chemists use the mathematical foundation of chemical kinetics to study the rates of reactions and reaction mechanisms. Unlike thermodynamics, which is concerned with the relative stabilities of the products and reactants (ΔG°) and their equilibrium concentrations, the study of kinetics focuses on the free energy of activation (ΔG‡) -- the difference in free energy between the reactant structure and the transition state structure—of a reaction, and therefore allows a chemist to study the process of equilibration. Mathematically derived formalisms such as the Hammond Postulate, the Curtin-Hammett principle, and the theory of microscopic reversibility are often applied to organic chemistry. Chemists have also used the principle of thermodynamic versus kinetic control to influence reaction products.
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Heavy minerals (minerals with a density greater than 2.89 g/cm3) have highly variable stabilities with respect to transport/weathering but the combined effects of chemical weathering, transport and diagenesis (and overall maturity) tend to decrease their percentage in the whole rock. Therefore, the average heavy mineral yield in sandstones is about 1% Boggs, S., 2009. Petrology of sedimentary rocks, Second Edition but can be a lot lower in old/recycled sandstones. The individual properties of heavy minerals being very different from one another and their relative abundance being a direct proxy of the nature of the source terranes and transport/recycling mechanism, heavy minerals have been used since the 19th century as a provenance tool.
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Actually, in his opinion, at the level of the observation process, a continuous interaction takes place between the individual subject and the world, an interaction that produces stabilities which therefore become objects, i.e. the objects that populate our perceptual world. In this sense, perceptual activity appears conditioned by the unfolding of the embodiment process and is linked to the cues offered by Reflexivity to meaning in action. In Carsetti's opinion, it is necessary, however, to emphasize that the classic reflexive models to the extent that they do not appear capable of creatively exploring the structures of reality are not really able to account for the creativity and continuous metamorphosis that characterize cognitive activity.
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If temperature and pressure are fixed, this equilibrium state is a constraint for the ratio of products versus reactants concentrations, obstructing the possibility to reach higher conversions. This limit can be overcome by removing a product of the reaction: in this way, the system cannot reach equilibrium and the reaction continues, reaching higher conversions (or same conversion at lower temperature). Nevertheless, there are several hurdles in an industrial commercialization due to technical difficulties in designing membranes with long stabilities and due to the high costs of membranes. Moreover, there is a lack of a process which lead the technology, even if in recent years this technology was successfully applied to hydrogen production and hydrocarbon dehydrogenation.
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The Irving–Williams Series refers to the relative stabilities of complexes formed by transition metals. In 1953 Harry Irving and Robert Williams observed that the stability of complexes formed by divalent first-row transition metal ions generally increase across the period to a maximum stability at copper: Mn(II) < Fe(II) < Co(II) < Ni(II) < Cu(II) > Zn(II). Specifically, the Irving–Williams Series refers to the exchange of aqua (H2O) ligands for any other ligand (L) within a metal complex. In other words, the Irving–Williams Series is almost exclusively independent of the nature of the incoming ligand, L. The main application of the Series is to empirically suggest an order of stability within first row transition metal complexes (where the transition metal is in oxidation state II).
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He has been awarded over 20 NASA New Technology Awards, 3 Patents, a NASA Exceptional Technology Achievement Medal (2004 Citation: "Linear Ion Trap Frequency Standards with Ultra-high Stability Suitable for Space and Ground Applications") and the NASA Space Technology Mission Directorate Ground Breaker Award (2015), all in the field of ion-trap atomic clocks. In 2009, he was awarded the highest IEEE prize in clock science and technology, the I. I. Rabi Award for 'Seminal work on the time variation of the fundamental constants and outstanding contributions to trapped ion clocks'. He was elected Fellow of the American Physical Society for 'developing fundamental physics tests of local Lorentz invariance and local position invariance, and for pioneering ion clock technology that has enabled stabilities exceeding those of the hydrogen maser'.
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Breslauer determined a DNA database that allows one to energetically map genome sequence information so as to correlate regions of differential stabilities with regions of differential biological functions.Breslauer Named Rutgers VP for Health Science Partnerships The database and its extensions also have been used to design probes and drugs with predictable hybridization and binding properties, a capability key to various diagnostic and therapeutic protocols. Breslauer has mapped the energetic consequences of DNA damage, knowledge critical to understanding the mechanisms of DNA repair, including why certain mutations escape repair and result in cancer. Most recently, Breslauer has elucidated the significance of metastable states within the rough energy landscapes of DNA molecules, information critical to our understanding of the molecular origins of triple repeat diseases, such as Huntington's disease and fragile X syndrome.
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While the sodium-ion battery technology is very versatile and can essentially be tailored to suit any application, it is widely believed that the first usage of sodium-ion batteries would be for all applications which are currently being served by lead-acid batteries. For such lower energy density applications, sodium-ion batteries would essentially be delivering much higher energy densities than current lead-acid batteries (1 – 5 times higher) at similar costs with enhanced performance (efficiency, safety, faster charging/discharging capabilities and cycling stabilities). These applications could be for smart grids, grid-storage for renewable power plants, the car SLI battery, UPS, telecoms, home storage and for any other stationary energy storage applications. The higher energy density sodium-ion batteries (typically those using non-aqueous electrolytes) would be well suited for those applications currently dominated by lithium-ion batteries.
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" # Tobin J. Marks 2001 "For highly original research that has had a major, lasting impact on important areas of chemical science, including f-element coordination and organometallic chemistry, homogeneous small molecule and polymerization catalysis, molecule- based photonics materials, low-dimensional electronic conductors, oxide chemical vapor deposition, high temperature superconductors, and metallocene anti-tumor agents." # Ralph Hirschmann 2002 "For the first synthesis of an enzyme in solution (RNase); the concept of stereolectronic control; the use of prodrugs to reduce toxicity; a new approach to the design of peptidomimetics; the discovery of valuable pharmaceuticals including Vaster, Lisinopril, Primaxin, Ivomec, Menacer, and Proscar." # John I. Brauman 2003 "For work that fundamentally changed the understanding f chemical structures and reactivities. For research that revealed intrinsic stabilities and reactivities and provided models for the dramatic effect of solvation on chemical reactions.
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The position of the main RAFT equilibrium (Figure 5) is affected by the relative stabilities of the RAFT adduct radical (Pn-S-C•(Z)-S-Pm) and its fragmentation products, namely S=C(Z)S-Pn and polymeric radical (Pm•). If formation of the RAFT adduct radical is sufficiently thermodynamically favorable, the concentration of active species, Pm•, will be reduced to the extent that a reduction in the rate of conversion of monomer into polymer is also observed, as compared to an equivalent polymerization without RAFT agent. Such a polymerization, is referred to as a rate-retarded RAFT polymerization. The rate of a RAFT polymerization, that is, the rate of conversion of monomer into polymer, mainly depends on the rate of the Propagation reaction (Figure 5) because the rate of initiation and termination are much higher than the rate of propagation.
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Promethium is the only lanthanide and one of only two elements among the first 83 that has no stable or long-lived (primordial) isotopes. This is a result of a rarely occurring effect of the liquid drop model and stabilities of neighbor element isotopes; it is also the least stable element of the first 84. The primary decay products are neodymium and samarium isotopes (promethium-146 decays to both, the lighter isotopes generally to neodymium via positron decay and electron capture, and the heavier isotopes to samarium via beta decay). Promethium nuclear isomers may decay to other promethium isotopes and one isotope (145Pm) has a very rare alpha decay mode to stable praseodymium-141. The most stable isotope of the element is promethium-145, which has a specific activity of and a half-life of 17.7 years via electron capture. Because it has 84 neutrons (two more than 82, which is a magic number which corresponds to a stable neutron configuration), it may emit an alpha particle (which has 2 neutrons) to form praseodymium-141 with 82 neutrons.
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