Composite samples, description

For composite samples the method discriminated separate Ti02 and CaC03 components and accurately determined their proportions. In addition, in combination with ultrasonic attenuation measurements, the size fractions of iron ore slurries below 10 and 30 pm were determined to within 1.3% and 1.0% respectively when compared with laser diffraction measurements [272]. According to Coghill et. al. velocity measurements are complementary to attenuation methods but better suited to the finer size fractions. A description of the analyzer and the results of plant feasibility tests and on-line installation has been presented [273]. 

Numerous methods are required to characterize drug substances and drug products (Chapter 10). Specifications may include description identification assay (of composite sample) tests for organic synthetic process impurities, inorganic impurities, degradation products, residual solvents, and container extractables tests of various physicochemical properties, chiral purity, water content, content uniformity, and antioxidant and antimicrobial preservative content microbial tests dissolution/disintegration tests hardness/friability tests and tests for particle size and polymorphic form. Some of these tests may be precluded, or additional tests may be added as dictated by the chemistry of the pharmaceutical or the dosage form. 

Finally a rough positive trend can be observed between 8 B values and values (Fig. 7). The correlation seems worse than between 8 B and 1/B but once again it is tempting to ascribe part of this scatter to an heterogeneity of the samples since contrary to B concentrations and isotopic compositions which were measured on the same piece of chert (but at different scales, bulk or micrometer scale), the 8 B values were measured on pieces of cherts resampled recently in the DSDP section as close as possible to the samples analyzed 25 years ago for values (see sample description). 

In this section, the differences between using CVD hybrid fillers and physically mixed hybrid fillers in polymer composites were studied. It shows an interesting result with regard to the thermal and hardness properties of composites. The synergistic effects of two components in the hybrid fillers helped each other perform as fillers and reinforcements in polymer composites. The thermal conductivities and hardnesses of phenolic/CNT—alumina hybrid composites were studied. The CNT—alumina hybrid (HYB compound) was produced via the CVD method, which was discussed in Section 5.6. The phenolic/CNT—alumina hybrid composites were fabricated using hot-mounted molding. Thermal conductivity was measured using the transient plane source method with a Hot-Disk Thermal Constant Analyzer. Table 5.4 shows the sample description in this study. 

To gain an understanding of the composition of the reservoir rock, inter-reservoir seals and the reservoir pore system it is desirable to obtain an undisturbed and continuous reservoir core sample. Cores are also used to establish physical rock properties by direct measurements in a laboratory. They allow description of the depositional environment, sedimentary features and the diagenetic history of the sequence. 

Variations in measurable properties existing in the bulk material being sampled are the underlying basis for samphng theory. For samples that correctly lead to valid analysis results (of chemical composition, ash, or moisture as examples), a fundamental theoiy of sampling is applied. The fundamental theoiy as developed by Gy (see references) employs descriptive terms reflecting material properties to calculate a minimum quantity to achieve specified sampling error. Estimates of minimum quantity assumes completely mixed material. Each quantity of equal mass withdrawn provides equivalent representation of the bulk. 

In the following description and discussion of our results, various criteria derived from the literature are used to determine whether or not each sample is of adequate preservation to allow it to be confidently included in a stable isotope study. The values applied in the various criteria have been found to be associated with archaeological bone collagen that retained an isotopic composition that was reflective of its diet, while the majority of samples that had values outside of the criteria did not retain an isotopic composition that reflected diet. The values for these criteria may vary slightly depending upon the collagen extraction methodology used, and such criteria are not exact. In this study samples that fall within the criteria values are deemed acceptable, and those that do not are deemed unacceptable. ... 

The design of this fish study centered on sample collection, preservation, preparation, analysis, and QA/QC. There was no discussion of the effect of compositing on the sample population. No description was given of statistical techniques to be applied to the data for reporting results and for comparison with action levels and future data. Unfortunately, the omission of a statistical framework during planning of the field study is the rule rather than the exception in hazardous waste investigations. 

It is important to emphasize that the Ts of a given sample is not a unique value, but rather depends on the analytical method and protocol employed, as well as a complete description of the sample, its composition (e.g., moisture content), and its history (i.e., under what conditions was it made... 

The Directive contains these other requirements concerning toxicity information and test data (1) Notifications must include descriptions of the studies conducted and methods used (Article 6(1), and Annex VII, Introductory Statements) (2) The tests must be performed according to the methods specified in Annex V (Article 3(1)), and must be "recognized and recommended by the competent international bodies where such recommendations exist" (Annex VII, Introductory Statements) (3) The persons who carry out the tests must comply with the principles of current good laboratory practice (Annex VII, Introductory Statements) and (4) The notifications must include the composition of samples used in testing, and the name of the persons responsible for carrying out the studies (Annex VII, Introductory Statements). 

The geology, textural characteristics of the nodules and bottom sediments, and descriptions of the substratum are summarized on site (Guliy 2004). Samples have been studied for its dimension, and mineralogical and chemical composition in accordance with their space distribution as well as age differences. 

Level 2 sampling programs are directed toward a more detailed representation of stream composition. They are not as inclusive as Level 1, in that resources are expended to improve information only on streams of a critical nature and on compound classes defined as present by Level 1 analysis. Level 2 sampling is optimized for specific compounds or classes of compounds contained in the streams sampled. Level 2 also provides a more quantitative description of the concentrations and mass flow rates of the various substances in the stream. Further, recommended procedures for compliance testing should be introduced into the program to ensure that the data acquired by the procedures selected for Level 2 sampling can be correlated with regulatory requirements. 

Another goal can be the description of the object in detail, e.g. the composition of a metal part as a function of distance from the surface, or the composition of various particles in a mixed particulate product e.g. pigments. Here i-t is necessary to know the size and the number of samples, the distance between samples or the sampling frequency. 

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