High-volume instrumentation

High voltage insulation materials, self-cleaning coatings for, 22 123 High Volume Instrument (HVI) systems, for classifying cotton, 8 13-14 High water velocities, in industrial water treatment, 26 141... 

Other instruments include the Calvet microcalorimeters [113], some of which can also run in the scanning mode as a DSC. These are available commercially from SETARAM. The calorimeters exist in several configurations. Each consists of sample and reference vessels placed in an isothermally controlled and insulated block. The side walls are in intimate contact with heat-flow sensors. Typical volumes of sample/reference vessels are 0.1 to 100 cm3, The instruments can be operated from below ambient temperatures up to 300°C (some high temperature instruments can operate up to 1000°C). The sensitivity of these instruments is better than 1 pW, which translates to a detection limit of 1 x 10-3 W/kg with a sample mass of 1 g. 

Sampling of these substances has been carried out following three approaches liquid absorbents [47], solid-phase microextraction (SPME) fibres [43] and filter substrates (mostly quartz fibre filters but also PTFE membranes [1, 42, 48, 49]). When filter substrates are used, atmospheric particles are collected over 24-h periods using high-volume (dichotomous or single-filter instruments [1, 48]), medium-volume or low-volume samplers (operated to ensure collection of sufficient aerosol mass [37, 50]). Samples were always stored at low temperamres (refrigerated or frozen) to ensure sample preservation. 

It should be noted that the sampler used in the study, (a stacked filter unit), collected only particles less than 15pm aerodynamic diameter, i.e. particles of respirable size. State standards for TSP are based on High Volume samplers which have no inlet cutoff. Hence, particles as large as 100 microns can be captured by these instruments. Therefore, measurements made in this study may not indicate whether particulate standards have been violated, since a significant portion of the total suspended particulate mass is not measured by the stacked filter unit (SFU). 

With the maturation of tandem mass spectrometry (MS/MS) instruments and methodologies, many commercial laboratories are switching to this technique, and high-sensitivity measurements on high volumes of samples are becoming routinely achieved. Since the future of steroid hormone analysis is MS/MS, only MS techniques will be described in this chapter. Immunoassay procedures have been well described and reviewed over the years and will cease to be mainstream methodologies within the next decade. 

CaviMax is a constant, high-flow-rate, single-orifice instrument with a maximum pressure of 8 MPa and orifices that can be interchanged in the range of 1.25 to 2.90 mm. The bubble dynamics can be further controlled through the use of a flow-throttling valve located just after the cavitation recovery zone. Other high-volume processors are available but were not used in this study. 

In this volume we have assembled all the methods used in our respective laboratories emphasizing the methodologies and techniques that are considered to be the most relevant, appropriate and least subject to error, whilst presenting critical assessments of all the approaches described. Where major specialized, high-cost instrumentation is required the text emphasizes the interpretation of the data obtained, the advantages and disadvantages of the technique and the chemical basis of the approach, rather than the specific details of how to operate the relevant instrument. 

Instrumented tablet presses with computer interfaces allow the pharmaceutical scientist to study the mechanism of compaction and the relationship of the mechanism to tablet-compaction properties and formulations. In addition, automated systems are useful to develop compression profiles for reference purposes, to control weight of tablets during development and production, and to monitor punch wear. This automation reduces the burden on personnel faced with the requirements of quality control. Merck Sharp and Dohme s major production facility in the United Kingdom is fully computerized to manufacture a high-volume tablet product as well as multiple-tablet products. " ... 

Ambient air concentration. High-volume samplers (VDI. 1976) fl] sucking about 400 m of ambient air through a 10 cm diameter Whatman 41 filter, were used during 21 h-periods. After filter conditioning, instrumental neutron activation analysis (INAA Al, Zn, Sb, Mn) and atomic absorption spectrometry (AAS Pb, Cd, Cr, As) were applied for analysis. 

With the introduction in the late 1960s of very high sensitivity instrumentation for the analysis of air and soil gas for Hg, it became possible to determine Hg levels in the field. Air surveys were commonly carried out from vehicles mounted with a precious-metal collector. Mercury within measured volumes of air passing over the collector amalgamated with the precious metal, which was subsequently heated to release the Hg for analysis. A less sensitive alternative method was to pass air directly through a Hg analyser without pre-concentration. 

The temperature of a polymer s melting, glass transition, crystallization, and its solid-state annealing are all known to have pressure dependencies.High-pressure instruments, such as the Gnomix Inc. (Colar-ado, U.S.A.), have been developed to study PVT relationships in polymers. In these experiments, the sample is placed in an incompressible fluid and then the desired pressure is applied. Full details of this technique, as well as a collection of P-V-T relationships for a wide range of polymers up to 200 MPa ( 30,000 psi) and 400°C, have recently been published. These data have mainly been collected isothermally to report the effects of pressure and temperature on the volume of... 

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