Chemical analyses and physical property measurements

Chemical analyses and physical property measurements made on the starting materials and the products of the ammonium fluotitanate reactions are shown in Table 2. The analytical data for the products of the iron ammonium fluoride reaction are shown in Table 3. Following treatment, the various zeolite products contained up to 16.1 wt.% Ti02 in the zeolites treated with ammonium fluotitanate, and up to 16.9 wt.% Fe203 in the zeolites treated with ammonium Iron fluoride. X-ray powder diffraction intensity is decreased in the substituted products, but retention of oxygen and water adsorption capacity indicates that pore volume has been retained. No extraneous peaks due to other crystalline phases were observed in the X-ray powder diffraction patterns of well washed products. 

Table 2. Chemical Analyses and Physical Property Measurements of the Starting Zeolites and the Products of the Ammonium Titanium Fluoride Reaction...

Information on purchased catalysts should include the lot numbers and dates of manufacture, and the amount of water and other volatile matter still contained on the catalyst. Specifications should provide data for chemical analyses, and physical-mechanical and physical-chemical properties. The latter information should include data concerning the average shape and sizes of particles, including oversized particles, fines content, and other measures of physical integrity. An example of information which could be included in purchase specifications for a fixed bed catalyst is shown in the following Table II. 

When rebreathing systems are used for the delivery of xenon, its concentration within the system needs to be closely monitored. Infrared gas analysers cannot detect xenon, since it is a single atom, and as it is chemically inert its physical properties must be utilised. Mass spectrometry is the most accurate method but it is expensive and it is impractical for clinical use. A calibrated katharometer combined with a galvanic oxygen sensor is a satisfactory alternative which provides a reasonably accurate measure ( 1%). 

The identification of the constituents of a complex mixture, such as coal, by molecular type may proceed in a variety of ways, but generally consists of three types of analyses chemical, spectroscopic, and physical. Mathematical formulas have been developed that use the properties measured by these techniquto derivestructuralparameters. Several good reviews on this subject are available.2 3... 

All of the above can be related to metal analysis as well as analysis for other components. Therefore, in order to analyse samples for metals or other unknown components, the analyst must have available the necessary information on the samples, suitable instruments, and procedures/methods for measuring the chemical and physical properties, all of which are an essential part of the analytical protocol. That reporting of measured results should include the support of statistical data is of paramount importance, and an inadequate knowledge of the same hinders confidence in the reported results. 

The objective in this study was to compare the long-term performance of these oils. To do this, changes in chemical and physical properties of the used oils were monitored using American Society of Testing Materials (ASTM) standard test methods [2]. Typically, used engine oil analyses include measurements of viscosity, acid and base numbers, water, glycol, soot, and metals content. In addition to the standard tests, fuel economy, deposit-forming tendencies, and friction and wear characteristics were determined on new and used oil samples in this study. 

Traditional methods of additive analysis and the required instruments are often expensive and require the efforts of a skilled technician or chemist. In some cases a single instmment can not provide analyses for the wide variety of additives a particular organisation utilises. Additionally, laboratory techniques rarely provide results in a timely fashion. Determination of physical properties is not the least important if one thinks of pigments, talc and other fillers. Application of spectroscopic techniques to polymer production processes permits real-time measurement of those qualitative variables that form the polymer manufacturing specification, i.e. both chemical properties (composition, additive concentration) and physical properties (such as melt index, density). On-line analysis may intercept plant problems such as computer error, mechanical problems and human error with respect to additive incorporation in the resin production. Characterisation and quantitative determination of additives in technical polymers is an important but difficult issue in process and quality control. 

However, physical properties such as API gravity and distillation are easy to measure. As a result, empirical correlations have been developed by the industry to determine chemical properties from tlicsv physical analyses. 

In general, hazard identification criterion represents the deviation of one or more measured variables from specified values. This is the basis upon which a significant percentage of risk analyses are done. For a chemical process, a number of measurable variables, physical properties, and states or positions of various parts of the overall equipment, e.g., pumps, valves, and motors, can be specified for every time or phase of the process. Certain deviations from the "standard" recipe or settings can then be defined in advance as hazardous, and thus can be used for initiation of an alarm at the early stage of a runaway or upset condition. 

Proper characterization of composite interfaces, whether it is for chemical, physical or mechanical properties, is extremely difficult because most interfaces with which we are concerned are buried inside the material. Furthermore, the microscopic and often nanoscopic nature of interfaces in most useful advanced fiber composites requires the characterization and measurement techniques to be of ultrahigh magnification and resolution for sensible and accurate solutions. In addition, experiments have to be carried out in a well-controlled environment using sophisticated testing conditions (e.g. in a high vacuum chamber). There are many difficulties often encountered in the physico-chemical analyses of surfaces. 

In on effort to establish the mechanism of coal flotation and thus establish the basis for an anthracite lithotype separation, some physical and chemical parameters for anthracite lithotype differentiation were determined. The electrokinetic properties were determined by streaming potential methods. Results indicated a difference in the characteristics of the lithotypes. Other physical and chemical analyses of the lithotypes were mode to establish parameters for further differentiation. Electron-microprobe x-ray, x-ray diffraction, x-ray fluorescent, infrared, and density analyses were made. Chemical analyses included proximate, ultimate, and sulfur measurements. The classification system used was a modification of the Stopes system for classifying lithotypes for humic coals. 

It is for these reasons that we have initiated this correlative study of peat petrography and peat industrial-chemical (coal quality) properties. Note that the information reported herein represents preliminary results based on a limited number of different types of peats that were analyzed for only a few coal quality tests (i.e., proximate analysis, ultimate analysis, and BTU content). Future studies will involve measurement of other petrographic parameters and include other industrial analyses (such as, gas and liquid yields, physical properties, organic chemical yields, and so forth). 

The choice of techniques for a specific problem depends not only on the nature of the material in question but also on the types of answer required. Methods for the determination of metal speciation range from very simple separations based on bulk physical properties to detailed structural analyses, which can measure interatomic distances and orientations. The complete chemical identification of a total unknown is a different problem from one in which a distinction must be made between, perhaps as few as two, possibilities. The foregoing chapter concentrates on techniques for chemical identification, which, together with the separation techniques which are discussed in depth elsewhere, make the determination of metal speciation possible. 

The small quantities of samples used for the determination of properties of natural materials by chemical analysis and calorimetric measurement must represent a large quantity (1000 kg or more) of a highly heterogeneous material, consisting of components with very different physical and chemical properties. The careful preparation of representative samples is a prerequisite for the reliability of the results of analyses and measurements. 

Reactions of considerable extent occur even in very dilute solutions of non-metals in alkali metals. Small concentrations of dissolved non-metals also influence physical properties of the molten metals. Very exact analyses are necessary to define the chemical potentials of non-metals in alkali metals. Oxygen can be removed from sodium, for instance, to such a degree, that only 0.1 to 0.01 wppm remain in solution. Electrochemical cells have the ability to estimate such extremely low concentrations. Carbon in liquid alkali metals, which are in contact with austenitic stainless steels, is in the same range of concentrations. Thus, only activity meters, based on gasanalytical devices or electrochemical cells, are able to measure such low carbon concentrations. There is still need for the development of analytical procedures to estimate nitrogen in alkali metals with the same sensitivity and accuracy. 

The choice of analytical and physicochemical methods for the characterization of polymorphs is dictated by the need to measure properties which ultimately depend on the different internal arrangements of the same molecules in these phases. When pseudopolymorphs are also considered, the range of suitable analytical techniques is significantly broadened owing to the presence in the crystal of the solvating molecule and the possibility of analysing the physical and chemical changes which may accompany both formation and decomposition of pseudopolymorphs. 

The adhesion properties of all types of polyolefins are not easy to explain because these properties are affected by different phenomena. Using of a single theory or mechanisms based on the physical and chemical adhesion manifestations is difiicult for the description of interdisciplinary nature and diversity. There is considerable information to discuss each of the adhesion mechanisms. Therefore, it is not possible to select only the thermodynamic theory of adhesion that is the best to describe the surface free energy of the polyolefin. All mechanisms and adhesion theories are implied by the diversity of polymer systems, which are embraced in combination with research for the analyses of adhesion properties. The physical and chemical composition in the first atomic layers dictates the adhesion and some other properties of the polymer materials. This layer represents underneath layer and this subsurface partially controls the outer layers. The double bonds and cross-linked stmctures limit the mobility macromolecules of polyolefins in the subsurface layers, which results in the functional group stabilization on the surface. Other basic research is necessary for an examination of the polymer subsurface layer and explanation of its effect changes of the surface properties. Moreover, for the improvement of quantitative measurements of adhesion, additional investigation is required. 

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