Purpose of This Study

The purpose of this study is twofold to compare four linear aqueous SEC columns made by Tosoh and Showa Denko in terms of composition and performance and to evaluate the effect of commercial PEO standards on the accuracy and precision of the MW and MWD of polyvinylpyrrolidone (PVP) and NIST PEO standards. In terms of performance, emphasis will be placed on factors not commonly covered by column manufacturers. Successful SEC conditions for PVP in water, in water/methanol, and in dimethylformamide can be found in the literature (8,9,10). This study deals mainly with the effects of column, mobile phase, and PEO standards on the MW and MWD of PVP. 

The purpose of this study is only intended to illustrate and evaluate the decision tree approach for CSP prediction using as attributes the 166 molecular keys publicly available in ISIS. This assay was carried out a CHIRBASE file of 3000 molecular structures corresponding to a list of samples resolved with an a value superior to 1.8. For each solute, we have picked in CHIRBASE the traded CSP providing the highest enantioselectivity. This procedure leads to a total selection of 18 CSPs commercially available under the following names Chiralpak AD [28], Chiral-AGP [40], Chiralpak AS [28], Resolvosil BSA-7 [41], Chiral-CBH [40], CTA-I (microcrystalline cellulose triacetate) [42], Chirobiotic T [43], Crownpak CR(-i-) [28], Cyclobond I [43], DNB-Leucine covalent [29], DNB-Phenylglycine covalent [29], Chiralcel OB [28], Chiralcel OD [28], Chiralcel OJ [28], Chiralpak OT(-i-) [28], Ultron-ES-OVM [44], Whelk-0 1 [29], (/ ,/ )-(3-Gem 1 [29]. 

Schiesser and Lapidus (S3), in later studies, measured the liquid residencetime distribution for a column of 4-in. diameter and 4-ft height packed with spherical particles of varying porosity and nominal diameters of in. and in. The liquid medium was water, and as tracers sodium chloride or methyl orange were employed. The specific purposes of this study were to determine radial variations in liquid flow rate and to demonstrate how pore diffusivity and pore structure may be estimated and characterized on the basis of tracer experiments. Significant radial variations in flow rate were observed methods are discussed for separating the hydrodynamic and diffusional contributions to the residence-time curves. 

The purpose of this study was to compare hepatotoxic effects of monobromo-benzene, 3 dibromobenzene isomers, hexabromobenzene and tetrabromobisphenol A with special attention paid to the dynamics of changes of selected indicators of liver necrosis during acute poisoning. 

A more detailed study has looked at the stmctural model of cross-linked E-plastomers. The purpose of this study was to develop correlations between dynamic properties such as the hysteretic loss and compression set of E-plastomers with key microstmctural variables such as density and molecular weight. 

The purpose of this study is to consider in more detail the influence of the size and nature of the counterion on the degree and extent of dissociation of poly(a-D)galacturonic acid already discussed in a previous paper [2], particularly to check the effect of screening the charges on the polyacid in the presence of different counterions. 

Since one of the key purposes of this study is to determine residue partitioning in the various processed commodities, every reasonable effort must be made to start the processing procedures with some level of residue in the RAC. If the RAC has residues present at harvest under normal GAP, then selective partitioning can be easily detected as the RAC is processed. However, if there is no residue in/on the RAC, the guideline indicates that exaggerated application rates may be required to obtain sufficient residue level to conduct a successful processing study. Usually a three- or... 

For the purpose of this study, particles are classified as Brownian or non-Brownian, where Brownian particles are defined as those for which the diameter is less than five microns and non-Brownian are those with diameter greater than five microns. The major focus of this work is on the second category. The particle release process has been studied both theoretically and experimentally, and it is found that for non-Brownian particles the surface charge and the electrolyte composition of the flowing phase are less significant factors than the hydrodynamic effects. However, Van der Waals forces are found to be important and the distortion of particles by these forces is shown to be crucial. 

Some of the isomers in this system have recently been investigated both theoretically and experimentally in a SIFT experiment.93 94 The primary purpose of this study was to identify the structural forms of the isomers produced in the association... 

It is important to update the bronchial dosimetry for radon daughters as new information becomes available. It is the purpose of this study to show that there is a potential for either significantly increased bronchial dose in the home per unit exposure if the ambient particle size is artificially reduced due, for example, to open-flame burning or use of kerosene heaters, or a decreased dose if hygroscopic particles dominate the indoor aerosol. 

Introduction and setting The purpose of this study was to identify and quantify the sources of heavy metals, especially lead, in soils and plants of the Lower Guadiana River basin and thereby model the potential mobility of lead. Other than direct pollution from mining, the main sources of heavy metal pollution in the environment are by diffuse pollution (Callender, 2004). In agricultural areas this can include lead from the use of pesticides, fertilizers and municipal sludge (Alloway, 1985). Metals can be attached or associated with different mineral phases in the soil, this along with environmental parameters determinesthe availability to plants. 

Risk assessment. The purpose of this study was risk assessment. The transfer to milk of 19 chemicals was simulated to predict those that may result in exposures to infants higher than the EPA... 

The purpose of this study was to explore the introduction of an OZT moiety onto the specific C-3 site of both l,2 5,6-di-0-isopropylidene-a-D-glucofuranose and 1,2 4,5-di-0-isopropylidene-p-D-fructopyranose, taking advantage of the well-defined frame of both carbohydrate structures to generate all possible OZT-isomers. These spiroheterocyclic structures could be constructed according to a simplified sequence based on a key stereoselective approach from uloses via epoxides or aziridines (Scheme 16). 

While there are a large number of both phosphorus additive and comonomer compounds available, no direct comparisons have been reported between the effectiveness of the two methods of incorporation, aside from some references to the lack of permanency of many additive compositions. The use of additives, on the other hand, may provide a greater flexibility, allowing the production of polymeric compositions of varying degrees of flame retardance, from the same base resin. The purpose of this study was to determine whether any real differences in effectiveness are detectable due to the method of incorporation of phosphorus into a polymer system. 

The purpose of this study was to investigate the extent of accumulation and the fate of molinate in the Japanese carp. 

The purpose of this study was to measure and compare the fracture toughness properties of Type 21-6-9 stainless steel for high-energy-rate and conventional forgings in the unexposed, hydrogen-exposed and tritium-exposed-and-aged conditions. 

The purpose of this study is to determine whether once-daily dosing of the lopinavir/ritonavir (Kaletra) tablet in combination with investigator-selected nucleoside/nucleotide reverse transcriptase inhibitors will reduce HIV viral load to very low levels in patients who have detectable viral loads with their current antiretroviral therapy. 

Electron crystallography of textured samples can benefit from the introduction of automatic or semi-automatic pattern indexing methods for the reconstruction of the three-dimensional reciprocal lattice from two-dimensional data and fitting procedures to model the observed diffraction pattern. Such automatic procedures had not been developed previously, but it is the purpose of this study to develop them now. All these features can contribute to extending the limits of traditional applications such as identification procedures, structure determination etc. 

For the purposes of this study the responses of a variety of intact and defective coatings were monitored and the results are compared with a.c. inpedance data. 

For the purposes of this study a variety of coatings applied to mild steel substrates were used. The coatings were chosen to provide a range of protection from poor to excellent. The coatings studied were ... 

The indicator category health and welfare, set up within the OECD framework for environmental indicators as a state category, only addresses the subject health and welfare from the farmer s side. From our point of view, the original OECD category lacks the two following important issues for the purposes of this study ... 

For the purpose of this study, the OECD set of environmental indicators for the agricultural sector has been adapted, taking into consideration only those indicators that directly affect the system of organic farming. Following indicator categories will be evaluated Ecosystem, natural resources, farm input and output, and health and welfare. 

The purpose of this study was to evaluate the linear calibration technique employing a single polydisperse standard and the search algorithm described above for non-aqueous and aqueous SEC. Comparison of this calibration technique to peak position, universal calibration, and Q-factor approximation techniques which make use of a series of narrow MWD polystyrene standards was also carried out. 

The purpose of this study is to determine the relative timing of Au mineralization in the context of the regional tectonic history. This was accomplished buy using cathode-luminescence to study gangue quartz in auriferous sulfide-quartz-carbonate veins. 

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