Commercial standards

Standardi tion. Design systems that incorporate component parts that are commercial standard, readily available, and common from system to system contribute to enhanced maintainabiUty and to greatly reduced investment in spare-parts inventories. 

Location of Deposits. Deposits of diatomite are known to exist on every continent and in nearly every country. Over half of the states in the United States reportedly contain diatomaceous earth deposits. In some cases, deposits of marine and freshwater origin occur almost side by side as do deposits of widely varying ages (5). Most of the deposits are not large enough or sufficiently pure to have commercial value. Production figures show the location of the deposits that meet commercial standards in both respects (7). 

The requirements within the product specification need to be expressed in terms that can be verified. Hence you should avoid subjective terms such as good quality components , high reliability , commercial standard parts , etc. as these requirements are not sufficiently definitive to be verified in a consistent manner. (See the later section on Design acceptance criteria and Part 2 Chapter 2 on Clarifying standards of acceptabili-fy-)... 

The GC-MS conditions are given in Table 11. Response factors are specific for the commercial standard, the particular clean-up procedure, and the GC-MS system used [24]. 

The reactors had relatively limited heat transfer capability and polyrates therefore had to be kept low. This was accomplished by operating at low temperatures. (The rate in the CSTR s was about. 5%/hr.). Since chain transfer agents were not employed, product Staudinger molecular weight was about 100,000, very high by current commercial standards. 

Calibration. Many approaches have been used to calibrate flow cytometric measurements. Including the comparison of flow and nonflow techniques (radiolabels, spectrofluorometry). In recent years, commercial standards have been introduced which are calibrated in fluorescein equivalents/particle (e.g., 3,000 or 500,000). With labeled ligands, calibration requires determining the relative quantum yield of the ligand compared to pure fluorescein and using the standards to analyze the amount bound on cells. Our ligands (fluorescein isothiocyanate derivatives) are typically 50% as fluorescent as fluorescein. 

Chip material Borosihcate glass Type of commercial Standard fused-... 

Fig. 1.26. Instrument DSC 2920 with DTA-measuring cell. This installation is not designed for low temperatures, but can be modified for this purpose. (Commercial standard installations for low temperatures have not been found by the author.) (Schema and photograph TA Instruments, Inc. New Castle DE 19720, USA.)...

High resolution (HR)-GC chromatograms of NP show a complicated isomer profile [46] with several tens of peaks (see Fig. 2.1.5(b), top). In contrast, commercial standards of OP are usually made up from f-octylphenol [p-(l,l,3,3-tetramethylbutyl)phenol], which is essentially... 

Fig. 2.3.5. Normal-phase HPLC chromatograms of commercial standards of (b) f-octylphenol and (a) 4-nonylphenol (85%). Column 100 X 4.6 mm2 Hypersil 3 NH2 (3 pm), gradient elution with re-hexane-2-propanol-H20, detection fluorescence, excitation 230 nm...

The more polar components have been characterised by FTICR—MS and HPLC-ESI-MS, and include excess PEG [CH30(E0)nH and HO(EO) Hl starting materials, confirmation of which was obtained by comparison with commercial standards [29]. ESI—MS, FTICR—MS and H NMR data analysis also indicated the presence of the Si—O—C byproduct 3, abbreviated to MDOH-0-(E0)ra-CH2CH=CH2, shown in Fig. 2.8.7. The formation of 3 can occur through side reactions of the... 

The product was identified by comparison of its retention time and mass spectrum with those of a commercial standard substance. Under the given conditions, the final molar conversion yield was 37.5 %. 

The response of the system is calibrated using a commercial standard solution (Sigma) to which known amounts of freshly made solutions of some of the unstable amino acids are added (glutamine, asparagine, tryptophan). In special circumstances, all kinds of other amino acids can be added. It is good practice to check the performance of the system at the end of a series with another commercial standard mix (e.g., Pierce). 

Under the 1948 commercial standard CS 12-48, fuel oil No. 1 is defined as intended for vaporizing pot-type burners and other burners requiring this grade, whereas No. 2 is defined as for general purpose domestic heating for use in burners not requiring No. 1. The No. 1 fuel is therefore specified to have a low 10% point in the ASTM distillation to ensure quick starting, and a low end point and low carbon residue to ensure clean vaporization. 

Missile Laboratory Rept 4, No 3J14N1, M Compilation of Data on Army, Navy. and Commercial Standard Electric.Squibs , Redstone Arsenal, Huntsville, Alabama (1956) 4) C.E.Baugh,... 

To identify systematic errors in the measurement of pH of rainwater, a careful study was conducted with 17 laboratories.19 Eight samples were provided to each laboratory, along with instructions on how to conduct the measurements. Each laboratory used two buffers to standardize pH meters. Sixteen laboratories successfully measured the pH of Unknown A (within 0.02 pH unit), which was 4.008 at 25°C. One lab whose measurement was 0.04 pH unit low had a faulty commercial standard buffer. 

Commercial standard solutions for flame atomic absorption are not necessarily suitable for plasma and furnace analyses. The latter methods require purer grades of water and acids for standard solutions and, especially, for dilutions. For the most sensitive analyses, solutions are prepared in a dust-free environment (a clean room with a filtered air supply) to reduce background contamination that will be detected by your instruments. 

These trivalent catalysts have been purported to have equal (47) or much better (2, 3) activity than the standard Cr(VI)/silica recipe. This would be a real boon to commercial producers who always look for better activity and prefer, for environmental reasons, not to handle Cr(VI) when possible. We have tried to confirm these findings many times, but if the trivalent catalysts have any activity at all in the high-pressure autoclave, it is infinitesimal by commercial standards. In fact, even Kazansky s reported activities at high pressure are microscopic in comparison (45). To our knowledge, no other producer has been able to use such a trivalent catalyst either. 

There must be literally millions of company standards in existence. Although they have relatively little significance in a national or international sense, they are the basis of many commercial contracts and, hence, are perhaps the most important standards of all. Unfortunately, the quality of commercial standards is very variable. 

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