Plastics, plating

In order to be able to recognize the type and function of the test point even without an inscription, it is recommended that the design of the test point conform to factory standards. Aboveground test points are usually installed in marker posts with a closable flap. The measuring cable is attached to a plastic plate with terminals (see Fig. 10-7). 

The plastic plates and terminals are fitted into cast housings inside concrete columns or in built-up areas, in cable junction boxes installed at walls. Belowground test points should be installed in built-up areas only in exceptional circumstances. In this case watertight, flush-mounted test stations are installed under a street-level covering and can be kept dry only by the most careful construction. 

Laminated plastics plate, sheet, and profile shapes... 

J. F. Mandell, Experimental Investigation of the Buckling of Anisotropic Fiber Reinforced Plastic Plates, Air Force Materials Laboratory Technical Report AFML-TR-68-281, October 1968. 

Thorough rinsing between the pretreatment steps is essential to prevent carry-over of solutions. The commonest plastic plated is ABS (acrylonitrile butadiene styrene copolymer) but procedures are also available for polypropylene and other plastics. In some proprietary processes, electroless copper solutions are used to give the initial thin conducting layer. 

Cooling tower packing (plastic plate or wooden lath)... 

Molecular modeling helps students understand physical and chemical properties by providing a way to visualize the three-dimensional arrangement of atoms. This model set uses polyhedra to represent atoms, and plastic connectors to represent bonds (scaled to correct bond length). Plastic plates representing orbital lobes are included for indicating lone pairs of electrons, radicals, and multiple bonds—a feature unique to this set. 

The measurement of optical density in AChE-biotests after analytical procedure can be done on special microplate photometer, for example, MicroReader 4 (Hyperion Inc., USA). The measurement of optical density was at X = 490 nm. For installation of microplate photometer parameters, the software of the device is used. According to our data, the best results were found with the use of modified 96-cells plate (Budantsev and Budantseva, 2005). They differ from a standard plastic plate by absence of cells bottom. 

TLC has similar applications to paper chromatography. The stationary phase is a coating, such as silica gel, on a glass or plastic plate. Depending on the TLC plate used, components may be separated based on differences in molecular weight, charge, or polarity (see Chapter 11). TLC with a 70% isopropyl alcohol mobile phase and a silica gel plate is an effective substitute for paper chromatography separation of amino acids. Nucleotides may be separated on a special silica gel plate and a 20% ethanol (in water) mobile phase. 

SECM is a useful electrochemical technique for imaging the smface topographical structure at solid/liquid interfaces. " " Briefly, the electrochemical system consists of a 10 pm Pt-ultramicroelectrode (UME) with Ag/AgCl (3 M KCl) as the reference and Pt as the coimter electrode. The unmodified- and Pyc modified-Nafion membranes (side-1) are carefully moimted on a homemade plastic plate on the bottom of the SECM cell. 

Double-antibody sandwich. Antibody is coated on or adsorbed to the plastic plate. The sample to be assayed containing the antigen (antibiotic) is added followed by a second antibody that is conjugated to the enz)rme (horseradish peroxidase, alkaline phosphatase, or 3 galactosidase). The substrate is added and the intensity of the color produced is directly proportional to the antigen in the test sample. 

The imaging plate (IP), approximately 0.5 mm thick, is a flexible plastic plate coated with polycrystals (crystal size 4-5 pm in diameter) of the phosphor, typically 150 pm thick, combined wifli an organic binder. The surface of the phosphor layer is... 

The most frequently used system is a glass or plastic plate coated with silica gel for routine applications the silica gel particle size is in the range 2-25 fim. The method of use for this system is as follows ... 

Antistatic agents consisting of trimethylalkylammonium halides such as tri-methylhexadecyl ammonium chloride were used by Iyama et al. (2) in coatings on plastic plates. 

A TLC system comprises three elements. As its name implies, one of the elements is thin layer coated mostly on a glass or plastic plate, which acts as a stationary phase. Such a plate is termed chromatoplate . The most popular materials (adsorbent) used to form the thin layer are silica gel and alumina powder. The other elements are a sample, and a solvent or solvent mixture (developer) which acts as a mobile phase to develop (elute) the sample. A stock solution of sample is prepared in advance of the TLC experiment and applied to the thin layer to form a spot. After removal of solvent contained in the spot, the sample is eluted with an appropriate... 

Thin-layer chromatography (TLC), sometimes also called planar chromatography, employ a stationary phase immobilized on a glass or plastic plate and an organic mobile phase. It is a rather old technique whose application in residue analysis has been limited in the past by poor chromatographic resolution, inadequate selectivity, and insufficient sensitivity (49). This was due to inherent problems in the quality of the available stationary phase materials and in the uniformity of the layers prepared. Today, the availability of affordable, precoated plates with acceptable performance and consistency has led to the general acceptance of TLC as an efficient procedure for residue analysis (50). The method is used preferentially when analysts must process large numbers of samples in a short period of time (51). 

Currently, a number of immunochemical tests are commercially available in a kit format for many drugs. The 96-well plastic plate is one of the more commonly used formats of polystyrene and polyvinyl sold supports. It is well suited to automation and high throughput uses due to the wide variety of equipment that has been developed to simplify reagent transfer, rinsing steps, and interpretation of results. 

A sheet of high-quality filter paper containing adsorbed water serves as the stationary phase in paper chromatography. However, thin-layer chromatography, which employs a layer of silica gel or other material spread on a glass or plastic plate, has often supplanted paper chromatography because of its rapidity and sharp separations (Fig. 3-5).16/96a 98-10°... 

The support medium may be a sheet of cellulose or a glass or plastic plate covered with a thin coating of silica gel, alumina, or cellulose. Large sheets of cellulose chromatography paper are available in different porosities. These may be cut to the appropriate size and used without further treatment. The paper should never be handled with bare fingers. Although thin-layer plates can easily be prepared, it is much more convenient to purchase ready-made plates. These are available in a variety of sizes, materials, and thicknesses of stationary support. They are relatively inexpensive and have a more uniform support thickness than hand-made plates. 

As discussed in Chapter 3, thin-layer chromatography utilizes a thin coating of silica gel on a glass or plastic plate to separate components of a mixture. The mixture of chemical substances to be analyzed is applied near one edge... 

The principle approach to immunoassay is illustrated in Figure 1, which shows a basic sandwich immunoassay. In this type of assay, an antibody to the analyte to be measured is immobilized onto a solid surface, such as a bead or a plastic (microtiter) plate. The test sample suspected of containing the analyte is mixed with the antibody beads or placed in the plastic plate, resulting in the formation of the antibody—analyte complex. A second antibody which carries an indicator reagent is then added to the mixture. This indicator may be a radioisotope, for RIA an enzyme, for EIA or a fluorophore, for fluorescence immunoassay (FIA). The antibody-indicator binds to the first antibody—analyte complex, free second antibody-indicator is washed away, and the two-antibody—analyte complex is quantified using a method compatible with the indicator reagent, such as quantifying radioactivity or enzyme-mediated color formation (see Automated instrumentation, clinical chemistry). 

Tfmt layer chromatography is similar to paper chromatography except that a coated glass or plastic plate is used instead of paper, and the results are visualized via an iodine vapor chamber. 

For vapor phase measurement of dry oil oxidation, the plate assembly shown in Figure 5 is used. The lower glass or terephtha-late plastic plate holds a disk of polyamide (1.2 x 0.1 cm) on which 1 pi of a suitable oil (linoleic acid, methyl linoleate, cottonseed oil) is deposited from a micropipette. A Buna "0" ring of 1.5-mm thickness is placed surrounding the spot and a similar plate with a polyamide disk is inverted over the ring forming a tight seal when clamped with "C" clamps. The plate assembly is placed in a 65°C draft oven with the receiver plate bottommost. 

For emulsion tests, polyamide-coated terephthalate plastic plates are attached powder-side down by double-faced transparent tape strips to the undersurface of the lid of 9 x 1 cm Pyrex Petri dishes. The plates, 2x3 cm, are cut from standard 20 x 20 cm polyamide-terephthalate plates used for thin-layer chromatography. They are Polygram - Polyamide-6 UV254, procured from Macherey-Nagel and Co. through Brinkmann Instruments, Inc., Westbury, N.Y. As indicated, they contain a fluorophore (zinc silicate) activated by short-wave UV, but not active in the 360-nm range used herein. 

Zhu et al. [76] designed and fabricated microfluidic devices on polymethylmethacrylate (PMMA) substrates for electrochemical analysis applications using an improved UY-LIGA process. The microchannel structures were transferred from a nickel mold onto the plastic plates by the hot embossing... 

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