Precision analyzer

The advantages of this type of detector are that even a noisy photodiode can easily be turned into a quantum limited detector and that the spectrum of the source can be analyzed precisely. 

A white crystalline material of the composition PtI(CH3)3 has been obtained in the following fashion.4 The yellow iodo derivative is converted to the sulfate by metathesis with silver sulfate. Addition of potassium iodide solution to an aqueous solution of trimethylplatinum(IY) sulfate yields a precipitate which, if recovered immediately by filtration, is white, analyzes precisely for PtI(CH3)3, is free of solvent, and decomposes at 190 to 200°. 

The factors which limit on-line process analyzer precision include ... 

Methods and technology were developed to analyze 1000 samples/yr of coal and other pollution-related samples. The complete trace element analysis of 20-24 samples/wk averaged 3-3.5 man-hours/sample. The computerized data reduction scheme could identify and report data on as many as 56 elements. In addition to coal, samples of fly ash, bottom ash, crude oil, fuel oil, residual oil, gasoline, jet fuel, kerosene, filtered air particulates, ore, stack scrubber water, clam tissue, crab shells, river sediment and water, and corn were analyzed. Precision of the method was 25% based on all elements reported in coal and other sample matrices. Overall accuracy was estimated at 50%. 

Instrument factors (instrument noise, non-linearity, temperature instability, drift, etc.). The factors which limit on-line NIR analyzer precision include ... 

E572 Stella, P., Spagliardi, G., Lovagnini-Scher, C.A., Guagnellini, E. and Okely, C. (1989). Kodak Ektachem 700 analyzer precision and accuracy evaluation Actual data from laboratory quality control over one year. Biochim. Clin. 13, Suppl. I /8, 150, Abstr. A 24. 

The examination of chemical shifts and coupling constants in proton and C NMR spectra has been used extensively for determining solution conformations. These techniques are particularly appropriate to the compounds discussed in this Chapter, as the chemical shifts of the two protons at the C-2 position are substantially different, as are their / coupling constants with the C-2 carbon atom. In 1994, the H NMR spectrum of 2-phenyl-1,3-dithiane was analyzed precisely, including up to V coupling data <94CJC1722>. The data confirm the expected chair conformation. 

The spectral dimension will be analyzed precisely in Section 4, which is devoted to obtaining reference solutions by the Monte Carlo method. 

In the course of the dehydration step, hydrogen sulfide also escapes. This may cause a problem, since the amount of alkali metal sulfide varies in an uncontrolled manner. In order to reach a high degree of polymerization, the alkali metal sulfide and the dichloro aromatic compound should be present in a stoichiometric ratio. Further, the hydrogen sulfide vaporized off in the dehydration step is a harmful substance. Therefore, the amount of hydrogen sulfide escaped in the dehydration step should be analyzed precisely to get the amount of sulfur still present in the reaction vessel. The hydrogen... 

Various analytical methods have been developed to detect the low isocyanate concentrations in the air of a urethane plant. One method uses atmospheric samples collected by passing air through absorber solutions. The absorbed isocyanates are then converted chemically into colour complexes, which are compared with a standard solution or measured photometrically. The colour intensity is converted to give the isocyanate concentration. A disadvantage of this method is that the sampling takes a considerable amount of time to collect a sufficient quantity of isocyanate to be analyzed precisely. 

It may be remarked that we have not found many pieces of research work which propose and analyze, precisely, interventions of the teacher during a given TLS. More attention has been paid again to this vertex of our "didactical rhombus" by a few researchers (Dumas-Carre Weil-Barais, 1998 Leach Scott, 2002) referring to a Vygotskian approach, but this dimension seems to be considered thus far in a quite general way that is independent of other dimensions of a given TLS. 

Ray, Johnston and Knox [75] investigated the c-spectra of ethylene-propylene copoli ers prepared with an isospecific catalyst system. The absence of propylene head-to-head or tail-to-tail inversions in these copolymers and their essentially complete isotactic enchainment enabled their spectra to be analyzed precisely. Assignments made previously for atactic ethylene-propylene copolymers, together with new assignments made possible by the simplicity of the isotactic copolymer spectra were used to obtain all n-add distributions through triads, P-P and E-E-centered tetrad distributions, and a number of pentad distributions. 

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