Source dissolution method

The possible preparation of InAs by crystallization from the melt depends also on the liquidus shape (especially in the In-rich region). A summary of previous liquidus measurements was reported by De Winter and Pollack (1986) who employed a source dissolution method based on the equilibration, at a fixed temperature, of a known quantity of high-purity indium with single crystals of InAs, the weight loss of which was determined. The experiments were carried out under a flux of hydrogen purified via permeation through palladium. 

Los Alamos is processing a wide variety of residues, including Pu-Be neutron sources, polystyrene-Pu02-U02 blocks, incinerator ash, Pu-U alloys and oxides, Pu-Zr alloys and oxides, Pu-Np alloys and oxides, Pu-Th alloys and oxides, etc. Processes have been developed for these scrap items (see Figure 2), but we need to know more about Pu-Np separations Pu-Th separations oxalate precipitations for both plus 3 and plus 4 valences valence stabilization dissolution methods for high-fired impure oxides in-line alpha monitors to measure extremely low concentrations of Pu and Am in HNO3 solutions and solubility of various mixtures of Pu02 and UO2 under a variety of conditions. 

The purpose of most experimental studies of diffusion is to obtain accurate diffusion coefficients as a function of temperature, pressure, and composition of the phase. For this purpose, the best approach is to design the experiments so that the diffusion problem has a simple anal3hical solution. After the experiments, the experimental results are compared with (or fit by) the anal3hical solution to obtain the diffusivity. The method of choice depends on the problems. The often used methods include diffusion-couple method, thin-source method, desorption or sorption method, and crystal dissolution method. 

Tracer diffusivities are often determined using the thin-source method. Self-diffusivities are often obtained from the diffusion couple and the sorption methods. Chemical diffusivities (including interdiffusivity, effective binary diffusivity, and multicomponent diffusivity matrix) may be obtained from the diffusion-couple, sorption, desorption, or crystal dissolution method. 

The kinetics of the enzymatic dissolution of elastin are very complex and the reaction of elastin fibers with elastolytic enzymes is commonly characterized by a lag phase or a markedly sigmoid time course (cf. Hall and Czerkawski, 1959 Naughton et al., 1960). The length of the slow initial phase is influenced by the enzyme-substrate ratio and the source and method of preparation of the elastin used in the assay the course of the reaction with different enzymes is also influenced by the presence or absence of salts, reducing agents, and many other substances. As a result... 

More recently, cellulose fibres have been investigated as potential precursors for self-reinforced polymer composites, as well summarised in a review by Eichhom et al. [191]. Numerous authors have reported the use of cellulose fibres from various sources, including wood pulp fibres [192, 193], filter and Kraft paper [194-197], microcrystalline cellulose fibres [198-202], sisal fibres [203, 204], ramie fibres [205], cotton fibres [206], regenerated cellulose (Lyocell) and cellulose fibres spun from an anisotropic phosphoric acid solution (Bocell) [207], and fibres from bacterial cellulose [208]. Two main technologies have been presented to produce these so-called self-reinforced cellulose or all-cellulose composites, and these are, first, the conventional impregnation of cellulose matrix into cellulose fibres and, second, a novel selective dissolution method in which the cellulose fibre surfaces are partially dissolved to form a matrix phase that bonds fibres together. 

Potassium Chloride. The principal ore encountered in the U.S. and Canadian mines is sylvinite [12174-64-0] a mechanical mixture of KCl and NaCl. Three beneficiation methods used for producing fertilizer grades of KCl ate thermal dissolution, heavy media separation, and flotation (qv). The choice of method depends on factors such as grade and type of ore, local energy sources, amount of clay present, and local fuel and water availabiUty and costs. 

In a bioanalytical method, analyses of blank samples (plasma, urine, or other matrix) should be obtained from at least six sources. Each blank sample should be tested for the possible interference of endogenous substances, metabolites, or degradation products. The response of the peaks interfering at the retention time of the analyte should be less than 20% of the response of a lower quantitation limit standard, and should be less than 5% of the response of the internal standard that was used [18, 19]. For dissolution studies, the dissolution media or excipients should not give a peak or spot that has an identical Rt or Rf value with the analyte [20]. 

Early optimism about the possibility of in vitro-in vivo correlation was tempered by the need for a performance test that would yield reproducible results (10). Even though not necessarily correlated to bioavailability, dissolution requirements were seen as useful in controlling variables in formulation or processing. Thus, from the start, sources of variability in the results were seen as factors to be minimized in any proposed compendial method. 

Figure 10 Rotational (tangential) flow (UA) as a function of stirring rate (co) for paddle (filled circles) and basket (open circles) Mean SD position S2 approximately 1 cm above the paddle and midway between the paddle shaft and the wall of the dissolution vessel. (Please note that, in contrast to simulation techniques such as, for instance, computational fluid dynamics, these data are based on dissolution experiments.) Source Data from Ref. 10, UPE method.

The most important sources of Mn are pyrolusite Mn02, hausmannite Mu304, and rhodochrosite MnC03. The metal is produced by dissolution of the minerals in acid, then electrolysis of the Mn(II) solution. An alternate method is to reduce Mn02 with Al. 

We used desorption of deactivated catalysts in vacuo at reaction temperatures into the ion source of a mass spectrometer as a method of examining desorbable intracrystalline fouling products. The method of dissolution of deactivated catalyst, followed by adsorbate analysis, that was reported by Venuto et al. (3, 4) was also used. The latter method gives composition and quantity of total adsorbate. The vacuum desorption technique provides information on the mobility—i.e., desorption dynamics, of desorbable (rather than total) adsorbed fouling products. 

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