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Study phase

Phase Studies. Phase systems that have been investigated during this period include (identified phases in square brackets) Na3P04-Zn3(P04)3 [Pg.216]

Averbuch-Pouchot, and J. C. Guitel, Acta Cryst., 1975, B31, 2680. [Pg.216]

For K 0 discrete aggregates are preferred and for 0 saddle-like structures are preferred. It has been found that xrand k are on the order of a few k T [123] and that k is negative. Others have obtained k and k on the order of unity and -0.5 in units of k T [60, 70, 71], respectively. There are also models where k is positive [124] due to how the enthalpy has been taken into account. Small differences in droplet size result in big variations of the derived values for k and k. Since they are often obtained from experimental results as the combination 2k + k) [Pg.61]

When the spontaneous curvature Hq is zero, either a lamellar flat structure, L , with both principal curvatures equal to zero, or a bilayer bicontinuous structure, [Pg.61]

saddle-shaped with both principal curvatures equal but of opposite sign, can be formed. Numerous investigations (both experimental and theoretical) that concern the bilayer bicontinuous phase have previously been carried out [123, 125-129]. [Pg.61]

For the C ,En microemulsions, it has been found that Hq depends linearly on the temperature, T  [Pg.61]


Figure B2.5.1 schematically illustrates a typical flow-tube set-up. In gas-phase studies, it serves mainly two purposes. On the one hand it allows highly reactive shortlived reactant species, such as radicals or atoms, to be prepared at well-defined concentrations in an inert buffer gas. On the other hand, the flow replaces the time dependence, t, of a reaction by the dependence on the distance v from the point where the reactants are mixed by the simple transfomiation with the flow velocity vy... Figure B2.5.1 schematically illustrates a typical flow-tube set-up. In gas-phase studies, it serves mainly two purposes. On the one hand it allows highly reactive shortlived reactant species, such as radicals or atoms, to be prepared at well-defined concentrations in an inert buffer gas. On the other hand, the flow replaces the time dependence, t, of a reaction by the dependence on the distance v from the point where the reactants are mixed by the simple transfomiation with the flow velocity vy...
The phases studied in the present work are those of material, Schrodinger waves, rather than of electromagnetic, light waves. Recently, it has been shown... [Pg.144]

Rodger P M, A J Stone and D J Tildesley 1988. The Intermolecular Potential of Chlorine. A Three Phase Study. Molecular Physics 63 173-188. [Pg.269]

Infrared absorption properties of 2-aminothiazole were reported with those of 52 other thiazoles (113). N-Deuterated 2-aminothiazole and 2-amino-4-methylthiazo e were submitted to intensive infrared investigations. All the assignments were performed using gas-phase studies of the shape of the vibration-rotation bands, dichroism, isotopic substitution, and separation of frequencies related to H-bonded and free species (115). With its ten atoms, this compound has 24 fundamental vibrations 18 for the skeleton and 6 for NHo. For the skeleton (Cj symmetry) 13 in-plane vibrations of A symmetry (2v(- h, 26c-h- Irc-N- and 7o)r .cieu.J and... [Pg.23]

Bleaching Powder. This material, known siace 1798, is made by chlorination of slightly moist hydrated lime, calcium hydroxide [1305-62-0] Ca(OH)2- It has the empirical formula Ca(OCl)2 CaCl2 Ca(OH)2 2H20. Its compositioa, loag a subject of coatroversy, was estabHshed by phase studies, microscopy, and x-ray diffraction techniques (241). The initial chlorination products are monobasic calcium chloride [14031-38-4] and dibasic calcium hypochlorite [12394-14-8] ... [Pg.474]

Computer simulation techniques offer the ability to study the potential energy surfaces of chemical reactions to a high degree of quantitative accuracy [4]. Theoretical studies of chemical reactions in the gas phase are a major field and can provide detailed insights into a variety of processes of fundamental interest in atmospheric and combustion chemistry. In the past decade theoretical methods were extended to the study of reaction processes in mesoscopic systems such as enzymatic reactions in solution, albeit to a more approximate level than the most accurate gas-phase studies. [Pg.221]

When liquid content of the feed is high, a condenser and a separator are needed. The liquid-to-gas ratio can be as high, so that even at reaction temperatures a liquid phase is present. The reactor still performs as a CSTR, however the response time for changes will be much longer than for vapor phase alone. Much lower RPM will be needed for liquid-phase studies (or liquid and gas phase experiments) since the density of the pumped fluid is an order-of-magnitude greater than for vapor phase alone. In this case a foamy mixture or a liquid saturated with gas is recirculated. [Pg.89]

After inserting (71) into (66) and some combinatorics we find the value of LO X) = where by X we denote one of the phases studied... [Pg.727]

In the case of solution phase studies, it is clear where we should draw a boundary between the parts of a system that ought to be studied quantum-mechanically and those that can be treated by the techniques of molecular mechanics. [Pg.263]

Despite its apparent simplicity, the PK pyrrole synthesis has retained its mystique since being discovered. Several investigations into the PK mechanism have been reported, including a gas phase study. Current evidence (intermediate isolation, kinetics, isotope effects) suggests the following (abbreviated) mechanism for the formation of pyrrole 13. However, the specific PK mechanism is often dependent on pH, solvent, and amine and dicarbonyl structure, especially with regard to the ringclosing step. [Pg.80]

Gas-phase studies where relevant tautomeric compounds are described are ihore scarce, but include uracil, thymine, and adenine [97CPL(269)39]. In the case of the 2-pyridone/hydroxypyridine equilibrium, the intensity of the OH and NH stretching vibrations was measured for eight temperatures in the range from 428 to 533 K in the gas phase. This allows determination otAH and AS for the equilibrium (92JPC1562). [Pg.47]

Three principal conditions in the leaching studies differed markedly from those in the single-phase studies ... [Pg.341]

Because of these differences, it is not surprising that speciation differs significantly in the two systems. The contrast in oxidation-state distributions between the single-phase studies and the leaching experiments is noteworthy. In the latter,... [Pg.341]

Roughly speaking the collisions are moderately weak. This conclusion is verified by comparison of theoretical and experimental data within the whole range of the gas phase studied in [89]. [Pg.108]

The irradiation (or ion bombardment) of solid solutions, where a scavenger can be present, should also be explored further. Here it will be important to ensure that the solids are indeed solutions before conclusions can be safely drawn. It is curious to note that the yields observed in frozen solutions are in several cases very similar to the yields in the pure crystalline solutes. This suggests the possibility that the frozen targets had segregated, and that the solute was in fact present as micro crystals. (If this is the case, it may well be that a new method can be developed on this basis for making phase studies at high dilution.)... [Pg.104]

The pKa of basic compounds as well as the buffered mobile phase were influenced by the organic solvent and depended on its proportion in the soluhon. The results indicated that the stationary phases and mobile phases studied were not suitably optimized for the estimation of lipophilicity of basic compounds. [Pg.417]

The field phase of an LSMBS is critically important. Close monitoring of shoppers by field phase study management personnel is required, especially when a sampling plan includes frequent collections, such as weekly or bimonthly. Missed, delayed, or deficient commodity samples can throw a laboratory off schedule, which in turn can adversely affect both the timeliness and the quality of the analyses. Missed, delayed, or deficient samples can also affect the study outcome and interpretation, because a statistical design typically requires a certain number of data points, each represented by analysis of a commodity sample. [Pg.240]

Experimental limitations initially limited the types of molecular systems that could be studied by TRIR spectroscopy. The main obstacles were the lack of readily tunable intense IR sources and sensitive fast IR detectors. Early TRIR work focused on gas phase studies because long pathlengths and/or multipass cells could be used without interference from solvent IR bands. Pimentel and co-workers first developed a rapid scan dispersive IR spectrometer (using a carbon arc broadband IR source) with time and spectral resolution on the order of 10 ps and 1 cm , respectively, and reported the gas phase IR spectra of a number of fundamental organic intermediates (e.g., CH3, CD3, and Cp2). Subsequent gas phase approaches with improved time and spectral resolution took advantage of pulsed IR sources. [Pg.184]

An interesting gas-phase study of the photolysis of ftmy-l-phenyl-2-butene has been published by Comtet.(39,40) He has found that (a) it was not possible to quench the formation of the cyclopropane product under conditions that reduced the fluorescence quantum yield, (b) sensitization by acetophenone only gave cis-trans isomerization, and (c) the quantum yield of cyclopropane formation in the direct photolysis decreases as n-butane is added to the reaction mixture. Comtet suggests that the data are consistent with a reaction from the second triplet state. [Pg.481]

Calorimetric Phase Studies of Model Amphiphilic Petroleum Recovery Systems... [Pg.292]

A vapour phase study of this azide showed it sometimes to explode when exposed to heat. [Pg.130]

Considerable interest in the subject of C-H bond activation at transition-metal centers has developed in the past several years (2), stimulated by the observation that even saturated hydrocarbons can react with little or no activation energy under appropriate conditions. Interestingly, gas phase studies of the reactions of saturated hydrocarbons at transition-metal centers were reported as early as 1973 (3). More recently, ion cyclotron resonance and ion beam experiments have provided many examples of the activation of both C-H and C-C bonds of alkanes by transition-metal ions in the gas phase (4). These gas phase studies have provided a plethora of highly speculative reaction mechanisms. Conventional mechanistic probes, such as isotopic labeling, have served mainly to indicate the complexity of "simple" processes such as the dehydrogenation of alkanes (5). More sophisticated techniques, such as multiphoton infrared laser activation (6) and the determination of kinetic energy release distributions (7), have revealed important features of the potential energy surfaces associated with the reactions of small molecules at transition metal centers. [Pg.16]


See other pages where Study phase is mentioned: [Pg.2554]    [Pg.15]    [Pg.15]    [Pg.1282]    [Pg.47]    [Pg.912]    [Pg.104]    [Pg.342]    [Pg.342]    [Pg.342]    [Pg.163]    [Pg.559]    [Pg.711]    [Pg.243]    [Pg.321]    [Pg.219]    [Pg.98]    [Pg.584]    [Pg.587]    [Pg.149]    [Pg.38]    [Pg.258]    [Pg.224]    [Pg.186]    [Pg.320]    [Pg.18]    [Pg.114]    [Pg.15]   
See also in sourсe #XX -- [ Pg.27 , Pg.107 , Pg.225 ]




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A-Silyl carbocations gas-phase studies

Application to the Structural Study of Disordered Phases

Boundaries, phase studies, definition

Case Study 1 Flow-induced Phase Separation in Polymer Solutions

Case studies in phase diagrams

Case studies in phase transformations

Chemical transformations in the dense fluid phase studied by high-pressure spectroscopy

Chiral mobile phase additives, chromatographic studies

Chiral stationary phases chromatographic studies

Chiral stationary phases computational studies

Clinical studies, phase active metabolites

Clinical studies, phase dose escalation

Clinical studies, phase metabolism

Clinical trials Phase 1 studies

Clinical trials Phase 4 studie

Coacervate phase, studied when

Concept study phase

Condensed phases experimental studies

Condensed-phase optimized molecular studies

Decision Rules During In-Study Phase and Associated Risks

Diabetes phase 2 studies

Disordered phases, structural studies

Drugs phase studies

Early phase clinical trials pharmacokinetic studies

Early phase clinical trials study designs

Earplug optimization study --- concluding phase

Experimental Methods for Studying Phase Behaviour of Mixtures at High Temperatures and Pressures

Experimental Methods to Study Hydrate Phase Equilibria

Experimental Studies on Precursor Phenomena in Displacive Phase Transformations

FERs from VB Studies of Free Energy Changes for PT in Condensed Phases

Feasibility study phase

Gas-phase adsorption model studies

Gas-phase reaction studies

Gas-phase studies

General Mechanistic Considerations From Solution and Gas-Phase Studies

General comments on study designs in early phase clinical studies

In-Study Validation Phase

Kinetic studies transient phase

Liquid phase studies

Liquid-phase adsorption studies

Liquid-phase reaction studies

Main study phase

Miscibility Studies and Phase Diagrams

Mobile phase studies using polymeric

Mobile phase, chromatographic studies

O-Silylvinyl cations gas-phase studies

Other data acquired in early phase clinical studies

Phase 0 clinical studies

Phase Composition Studies

Phase I clinical studies

Phase I studies

Phase I study designs

Phase I/II studies

Phase II clinical studies

Phase II studies

Phase II/III studies

Phase III clinical studies

Phase III studies

Phase IV clinical studies

Phase IV studies

Phase Illb studies

Phase behavior study

Phase behavior study cation

Phase behavior study, microemulsions

Phase behavior study, microemulsions cation

Phase diagram studies

Phase diagrams case studies

Phase diagrams, miscibility studies

Phase equilibrium studies

Phase lib studies

Phase separation Light scattering study

Phase single-centre studies

Phase study, spectral series

Phase transitions calorimetric studies

Phase transitions crystallographic study

Phase-separation studies

Placebo-controlled studies phase

Plant substance phase 311 studies

Post-marketing studies Phase

Preclinical studies phases

Quenching , phase changes studied

RTD Studies on Liquid-phase Flows

Reactive intermediates solution-phase studies

Reasons for studying phase diagrams

STM Studies of Anchoring Phase Transitions at Nematic Interfaces

Single-crystal phase transition studie

Single-crystal phase transition studie motions

Small Organic Molecules on Solid Phase Target Selection and Solution Studies

Solid phase analysis mineral composition study

Solid phase analysis morphology study

Solid phase study

Solid-phase extraction case study

Solution-phase study procedure

Source study, phases

Special LDA-Systems for Two-Phase Flow Studies

Studies in Lysozyme and the Generic Protein Phase Diagram

Studies of intermolecular interactions in the gas phase

Studies, first time in man phase

Study of Equilibrium Phase Diagram Around Langasite

Study of Equilibrium Phase Diagram Around Langatate

Study planning phase

The Phases of a Study

Theoretical studies orbital phase theory

Third-phase formation studies

Three Phase Bone Study

Transmission electron microscopy phase transformations studies

Vapor phase, studies

Vapor-phase Fourier transform IR studies

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