Solid phase study

All these advances have resulted not only in increases in resolution but have also alleviated the detection problems to a considerable extent. As a result, the last decade has seen a dramatic growth in 15N- and 170-NMR spectroscopy as a versatile method for studying molecular structure, both in isotropic (liquid) and anisotropic (solid) phases. Studies at a natural abundance level of the nucleides are now commonplace. The scope of chemical applications extends from inorganic, organometallic and organic chemistry to biochemistry and molecular biology, and includes the study of reactive intermediates, biopolymers and enzyme-inhibitor complexes. 

The following shows the development of the predictive QSPR model. The descriptors considered for the model include geometric and topological descriptors, electronic properties, charge-dependent properties, physico-chemical properties, and accumulation factors. The solid phases studied include three soil types (mollisol, ultisol, and aridisol) and two aquatic sediments. 

Phenylmercuric ion was introduced to the various solid phase-seawater suspensions as an aqueous solution of phenylmercuric acetate (PMA). Adsorption of phenylmercuric ion onto all solid phases studied, except bentonite clay, was noted at solid concentrations of 150 ppm (suspended). Adsorption isotherms for humic acid, hydrous MnO and amorphous Fe(OH)2 are shown in Figure A. Values of Kads for phenylmercuric ion and these solid phases are listed in Table IV. 

The solid phases studied in the solubility experiments are assumed by the review to have the composition CaSe03-H20 and the solubility equilibrium is written ... 

A gas phase electron diffraction study of 1,3-dithiane was carried out by Adams and Bartell. It suggested a chair conformation to be the most stable, in agreement with solution and solid phase studies <77JST(37)261>. 

There is plenty of information available in literature on liquid crystalline and isotropic phases of different surfactants, but the study of the solid phases is limited to only soaps [12-19]. The basic reason for the lack of solid phase studies of synthetic surfactants is their limited use in solid form. The low KP of these surfactants limits their use to liquid products. Owing to a relatively high KP, sodium cocoyl isethionate (SCI), alkyl glycerol ether sulfonate (AGES), and sodium cocoyl monoglyceride sulfate (CMOS) form solid phases at room temperature, but there is hardly any information available on these solid phases. 

Many of the properties of the cement paste are determined by its chemical nature and micro structure. Microstructure constitutes the nature of the solid body and that of the non-solid portion, viz., porous structure. Microstructural features depend on many factors, such as the physical and chemical nature of the cement, type and the amoimt of admixture added to it, temperature and period of hydration, and the initial w/c ratio. The solid phase study includes examination of the morphology (shape and size), bonding ofthe surfaces, surface area, and density. Porosity, pore shape, and pore size distribution analysis is necessary for investigating the non-solid phase. Many of the properties are interdependent, and no one property can adequately explain the physico-mechanical characteristics of cement paste. 

Wang H, Ganesan A. Total synthesis of the fumiquinazoline alkaloids solid-phase studies. J. Comb. Chem. 2000 2 186-194. 

This study detects the defect of the void and the exfoliation in the solid phase diffusion bonding interface of ductile cast iron and stainless steel with a nickel insert metal using ultrrasonic testing method, and examine the influence of mutual interference of the reflectional wave both the defect and the interface. 

This study was in real time measured that the reflective echo height of the bonding interface in the solid phase diffused bonding process of carbon steel and titanium using ultrasonic testing method. As a result, the following were made discernment. 

Two nucleation processes important to many people (including some surface scientists ) occur in the formation of gallstones in human bile and kidney stones in urine. Cholesterol crystallization in bile causes the formation of gallstones. Cryotransmission microscopy (Chapter VIII) studies of human bile reveal vesicles, micelles, and potential early crystallites indicating that the cholesterol crystallization in bile is not cooperative and the true nucleation time may be much shorter than that found by standard clinical analysis by light microscopy [75]. Kidney stones often form from crystals of calcium oxalates in urine. Inhibitors can prevent nucleation and influence the solid phase and intercrystallite interactions [76, 77]. Citrate, for example, is an important physiological inhibitor to the formation of calcium renal stones. Electrokinetic studies (see Section V-6) have shown the effect of various inhibitors on the surface potential and colloidal stability of micrometer-sized dispersions of calcium oxalate crystals formed in synthetic urine [78, 79]. 

Traditionally one categorizes matter by phases such as gases, liquids and solids. Chemistry is usually concerned with matter m the gas and liquid phases, whereas physics is concerned with the solid phase. However, this distinction is not well defined often chemists are concerned with the solid state and reactions between solid-state phases, and physicists often study atoms and molecular systems in the gas phase. The tenn condensed phases usually encompasses both the liquid state and the solid state, but not the gas state. In this section, the emphasis will be placed on the solid state with a brief discussion of liquids. 

Unlike melting and the solid-solid phase transitions discussed in the next section, these phase changes are not reversible processes they occur because the crystal stmcture of the nanocrystal is metastable. For example, titania made in the nanophase always adopts the anatase stmcture. At higher temperatures the material spontaneously transfonns to the mtile bulk stable phase [211, 212 and 213]. The role of grain size in these metastable-stable transitions is not well established the issue is complicated by the fact that the transition is accompanied by grain growth which clouds the inteiyDretation of size-dependent data [214, 215 and 216]. In situ TEM studies, however, indicate that the surface chemistry of the nanocrystals play a cmcial role in the transition temperatures [217, 218]. 

The ability to control pressure in the laboratory environment is a powerful tool for investigating phase changes in materials. At high pressure, many solids will transfonn to denser crystal stmctures. The study of nanocrystals under high pressure, then, allows one to investigate the size dependence of the solid-solid phase transition pressures. Results from studies of both CdSe [219, 220, 221 and 222] and silicon nanocrystals [223] indicate that solid-solid phase transition pressures are elevated in smaller nanocrystals. 

More recently, studies of the hysteresis of these phase transitions have illuminated the importance of kinetic factors in solid-solid phase transitions [224]. The change between crystal stmctures does not occur at the same point when pressure is increasing, as when it is decreasing the difference between this up-stroke and down-stroke pressure... 

Quantitative studies of solid-state organic reactions were performed by Glazman (267. 268). Equal amounts of acetic anhydride and 2-aminothiazole (grain diameter 0.15 mm) were mixed for 20 rain, and the mixture was heated in a glycerol bath at 0.5°C per minute. Heating curves showed that the reaction starts in the solid phase the use of an eutectic composition of organic reactants increases the yields. 

A simple, rapid and seleetive eleetroehemieal method is proposed as a novel and powerful analytieal teehnique for the solid phase determination of less than 4% antimony in lead-antimony alloys without any separation and ehemieal pretreatment. The proposed method is based on the surfaee antimony oxidation of Pb/Sb alloy to Sb(III) at the thin oxide layer of PbSOyPbO that is formed by oxidation of Pb and using linear sweep voltammetrie (LSV) teehnique. Determination was earried out in eoneentrate H SO solution. The influenee of reagent eoneentration and variable parameters was studied. The method has deteetion limit of 0.056% and maximum relative standard deviation of 4.26%. This method was applied for the determination of Sb in lead/aeid battery grids satisfaetory. 

In this work hybrid method is suggested to determine anionic surfactants in waters. It is based on preconcentration of anionic surfactants as their ion associates with cationic dyes on the membrane filter and measurement of colour intensity by solid-phase spectrophotometry method. Effect of different basic dyes, nature and hydrophobicity of anionic surfactants, size of membrane filter pores, filtration rate on sensitivity of their determination was studied. Various cationic dyes, such as Methylene Blue, Crystal Violet, Malachite Green, Rhodamine 6G, Safranin T, Acridine Yellow were used as counter ions. The difference in reflection between the blank and the sample was significant when Crystal Violet or Rhodamine 6G or Acridine Yellow were used. 

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