Testing Methodology

Properties. Properties of stmctural siHcon nitride ceramics are given in Table 2. These values represent available, weU-tested materials. However, test methodology and the quaHty of the specimens, particularly their surface finish, can affect the measured values. Another important material property is tensile strength. Values obtained on Norton s NT154 material are 750 MPa at RT, 500 MPa at 1200°C, and 350 MPa (50,000 psi) at 1400°C (62). 

Relaxations of a-PVDF have been investigated by various methods including dielectric, dynamic mechanical, nmr, dilatometric, and piezoelectric and reviewed (3). Significant relaxation ranges are seen in the loss-modulus curve of the dynamic mechanical spectmm for a-PVDF at about 100°C (a ), 50°C (a ), —38° C (P), and —70° C (y). PVDF relaxation temperatures are rather complex because the behavior of PVDF varies with thermal or mechanical history and with the testing methodology (131). 

Controversy over test methodology, and concern with the welfare of test animals, has been highly pubhci2ed in the last decade, and various states have proposed legislation to ban animal tests. Significant effort has been devoted to developing nonanimal alternative tests and predictive methods. Progress has been made, but no entirely satisfactory substitute has been found to date (142). 

CCPS has developed guidelines for the measurement of PSM performance that provide useful ideas on measurement. Their approach for developing performance measures integrates Quality Management with a well-tested methodology for developing measures based on mathematical algorithms derived from expert assessment of system performance. The purpose was to identify well-defined, measurable, and practical indicators of performance that are updated on a schedule which makes the performance measure continuously useful. To date, measures have been developed for... 

Corrosion of solders used in the electronics industry is usually a function of the presence of residues from various manufacturing and assembly operations. Corrosion in heat exchangers, particularly in automobiles is a more significant problem and a test methodology has been described as well as various factors controlling the corrosion of tin-lead alloys in radiators... 

A., Gauvrit,). Y., Lanteri, P., Veuthey, J. L. Simplification of a chromatographic test methodology for evaluation of base deactivated supports. Chromatographia 2002, 56, 665-671. 

The determination and analysis of sensory properties plays an important role in the development of new consumer products. Particularly in the food industry sensory analysis has become an indispensable tool in research, development, marketing and quality control. The discipline of sensory analysis covers a wide spectrum of subjects physiology of sensory perception, psychology of human behaviour, flavour chemistry, physics of emulsion break-up and flavour release, testing methodology, consumer research, statistical data analysis. Not all of these aspects are of direct interest for the chemometrician. In this chapter we will cover a few topics in the analysis of sensory data. General introductory books are e.g. Refs. [1-3]. 

Primary container-closure system-related data will need to cover storage, transportation, and use. The choice of materials of construction, their description, and the ability of the container-closure system to protect from moisture and/or light will need to be considered. The compatibility of the container-closure and its contents will need to consider sorption, leaching, and safety. The performance of the container-closure system will also need to be considered in terms of dose delivery from any associated device that is to be supplied as part of the product. Container-closure components will require adequate specifications covering description, identification, critical dimensional tolerances, and test methodology (including pharma-copeial and noncompendial methods). More data are likely to be required for liquid or semi-liquid products than for solid dosage forms. In the latter, product stability data and container-closure system specifications may suffice. 

The objectives of this research are to develop short-term in vitro fatigue test methodologies that will predict long-term in vivo performance of elastomers used in cardiac assistance and related devices and to evaluate the fatigue life of candidate materials for potential use in these applications. 

The range of application of shear cell testing methodology is seen in Tables 2-6. Table 3 relates the flow properties of mixtures of spray-dried lactose and bolted lactose. These mixtures, in combination with the excipients tested, cover a broad range of flow. Tables 4 and 5, for example, show lot to lot variations in the flow properties of several materials, and Table 6 shows the variation in flow properties of bolted starch, sucrose, and phenacetin at different relative humidities (RH). Figure 8 presents the yield loci of sucrose at four different consolidation loads. Also shown in the figure are the shear indices determined at each consolidation load. 

A discussion of test methodology is beyond the scope of the present paper. However, the fact that established tests do not accurately reflect the behavior of materials in fires has been widely recognized (9), and the search for more meaningful techniques for the evaluation of engineering materials has continued to be a valid research objective. The development of the cone calorimeter, a bench-scale tool for the evaluation of fire properties of materials (10a) at NBS, is of particular significance in this context. 

In summary, new brominated flame retardants have essentially met the challenge for thermoplastics that do not meet current requirements (e.g. a V-0 rating) without additives. More stringent flammability requirements for advanced materials and applications, coupled with improved test methodology (e.g. lOa-b) may shift the focus of research to other approaches. 

Organisation of Economic Cooperation and Development, Skin Sensitisation Testing Methodological Considerations, Tech. Rep. No. 78, Paris, 1999. 

The second issue involves the nature of published material itself. Due to journal space limitations and/or other factors, it is rare to find enough detail presented for a reader to make an independent evaluation of the value of the irritation data. Sometimes the test methodology is not defined, making direct comparisons to results obtained in other laboratory situations tenuous at best. Often raw data are lacking, and the results are reduced to either a plus-minus score or a broad categorization (mild, moderate, severe), so that a more specific appraisal cannot be made. These factors preclude the resolution and evaluation of seemingly conflicting data that one often finds in the literature. 

Laboratory-scale test procedures consisting of jar test studies have been used for years, and the test methodology developed is such that full-scale designs can be developed from these studies with a high degree of confidence. A jar test is a series of bench-scale laboratory procedures made on 1- or 2-1 water samples to determine the most effective water treatment method. Tests are performed to identify the most effective coagulants, optimum dosage, optimum pH, and most effective order in which to add various chemicals. 

Several in vitro tests are currently employed to assure drug product quality. These include purity, potency, assay, content uniformity, and dissolution specifications. For a pharmaceutical product to be consistently effective, it must meet all of its quality test criteria. When used as a QC test, the in vitro dissolution test provides information for marketing authorization. The dissolution test forms the basis for setting specifications (test, methodology, acceptance criteria) to allow batch release into the market place. Dissolution tests also provides a useful check on a number of physical characteristics, including particle size distribution, crystal form, etc., which may be influenced by the manufacturing procedure. In vitro dissolution tests and QC specifications should be based on the in vitro performance of the test batches used in in vivo studies or on suitable compendial specifications. For conventional-release products, a single-point dissolution... 

Sorption and/or desorption processes, a part of the removal/reduction/ retardation (RRR) processes for chemical constituents in leachates, were determined by a testing methodology using a series of laboratory simulations. 

The potential impacts of organic leachates from complex mixtures on surface and ground waters appear to be of environmental concern, thus the testing methodology provides a systematic approach for such evaluations. 

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