Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Species measured

Eckbreth A C, Dobbs G M, Stufflebeam J H and Tellex P A 1984 CARS temperature and species measurements in augmented jet engine exhausts App/. Opt. 23 1328-39... [Pg.1232]

Essential features of an automated method are the specificity, ie, the assay should be free from interference by other semm or urine constituents, and the sensitivity, ie, the detector response for typical sample concentration of the species measured should be large enough compared to the noise level to ensure assay precision. Also important are the speed, ie, the reaction should occur within a convenient time interval (for fast analysis rates), and adequate range, the result for most samples should fall within the allowable range of the assay. [Pg.392]

Separate sample blanking requires an additional analytical channel, and is therefore wasteflil of both reagents and hardware. An alternative approach that is used on several automated systems, eg, Du Pont ACA, BM-Hitachi 704, Technicon RA-1000, is that of bichromatic analysis (5) where absorbance measurements are taken at two, rather than one, wavelength. When the spectral curves for the interference material and the chromogen of the species measured differ sufficiently, this can be an effective technique for reducing blank contributions to assay error. Bichromatic analysis is effective for blanks of both the first and second type. [Pg.393]

Fig. 14.4 Oxygen isotopic composition of atmospheric species measured to date (After Thiemens, M., Ann. Rev. Earth Planet. Sci. 34, 217 (2006)). For these data, m, Equation 14.31 is approximately (0.7 < m < 0.9) indicating for these materials the fractionation is better described as anomalous rather than mass independent ... Fig. 14.4 Oxygen isotopic composition of atmospheric species measured to date (After Thiemens, M., Ann. Rev. Earth Planet. Sci. 34, 217 (2006)). For these data, m, Equation 14.31 is approximately (0.7 < m < 0.9) indicating for these materials the fractionation is better described as anomalous rather than mass independent ...
The electrophoretic mobility usually found in standard reference tables is a physical constant determined for complete dissociation extrapolated to infinite dilution. However, the mobility of ionic species measured under practical conditions often depends on protonation/deprotonation equilibria... [Pg.21]

Infrared spectra of VjO, supported catalysts after calcination at 550°C showed the V=0 stretching vibration band at 923 cm. This indicates that surface vanadium species is located on the basic sites within the AIPO,-5 surface. According to the diffused reflectance spectra of the samples with low VjO, contents, the vanadium species supported on AIPO4-5 surface was mainly in a distorted tetrahedral environment. However, upon increasing the V Oj coment, crystalline VjOj was formed on the AIPO -S surface prior to the formation of approximately a monolayer of the surface vanadium species. The vanadium species measured by EPR and DRS and catalytic properties of vanadium loaded VjOg/AIPO -S were similar to those of vanadium substituted VAPO -S. [Pg.187]

A critical requirement for the success of receptor models for atmospheric particles Is that the compositions of particles from all major sources in an area be accurately known. Chemical element balances (CEBs) of 130 samples taken In Washington, D.C. and analyzed for 40 elements yielded nearly the same source strengths when 28 elements are used In the least-squares fit as when only nine carefully chosen elements are used. Certain elements are important to the stability of CEB fits (Na, Ca, V, Mn, As and Pb) and should be measured carefully In particles from sources. For three of the nine elements (Al, Fe and Zn), other elements can serve as surrogates (many lithophlles for Al and Fe, Sb and Cd for Zn). Measurements on many more sources of each Important type should be done In order that trends can be observed that will allow one to predict compositions of particles from unmeasured sources. Instack measurements should Include collections of at least two size fractions of particles plus vapor-phase species. Measurements of at least 20 elements plus some classes of carbonaceous material should be made. [Pg.51]

There are some sampling sites located on mountains that have been used to assess the relative amounts of S02 oxidation that occurs in clouds versus in the gas phase. In these cases, fixed sampling sites can be used and the concentrations of S02, sulfate, and associated species measured in the gas and particle phases as well as in the cloudwater as the cloud passes over the sampling site (e.g., see Saxena and Lin, 1990 Aneja and Kim, 1993 and Burkhard et al., 1995). [Pg.297]

A number of studies of bacterial mutagenicity and the PAHs and PACs responsible for it have been carried out in southern California. At the risk of seeming somewhat parochial, we describe briefly the results of some of them, since they are unique in the breadth of parameters and species measured concurrently. A key objective of these studies was to better understand the role played by atmospheric reactions in determining the composition and mutagenicity of fine particles... [Pg.493]

TABLE 11.4 Some Species Measured by Mass Spectrometry in the Atmosphere up to about 1990 ... [Pg.561]

Species (measured parameter) Concentration in the River Concentration in the Well... [Pg.572]

There are a large number of spectroscopic reports involving Erythrosin, particularly from Russian laboratories. The near-IR absorption spectra of both Eosin and Erythrosin triplets and their dianion radical cations have been reported [236], the pK s of both species measured [237], and the influence on radiative and radiationless transitions by external heavy atoms such as iodide reported [238]. The nonradiative decay of Erythrosin in water at room temperature has also been studied by photoacoustic spectroscopy [239],... [Pg.351]

Under normal d-c operating voltages, the selection of the applied potential is determined by the species measured, cell design, carrier gas composition, and detector contamination. [Pg.259]

Tabic 1. The different instruments discussed in this paper, coverage of their measurements, species measured and the satellite. The list is not intended to be complete, but merely to illustrate the currently available instrumentation. ... [Pg.305]

Instrument Name Height of measurement Species measured Platform... [Pg.307]

Early work with aqueous solutions containing ionic solutes in a 1 1 mixture of water and glycerol showed that factors such as the pH of the solution and salt content had significant and reproducible effects on the distribution of ionic species measured by the mass spectrometer. Using the Henderson-Hasselbalch equation under simplifying conditions (at low ionic strengths with acid components whose pKa s lie between 3 and 10), it was shown that the pKa of an acid could be accurately determined knowing the pH of the solution and the concentrations of acid and base species (2). With respect to the measurement of this constant by FABMS,... [Pg.210]

The ethyl radical formed during the dealkylation process was trapped using 2-methyl-2-nitrosopropane to form tert-butylethylnitroxide 34, where the coupling constants and g-factors of the trapped species measured by electron spin resonance (ESR) analysis matched the literature values for ferZ-butylcthylnitroxidc 34 exactly. [Pg.431]

The most recent publication reviewed was by Einspahr and Harder (63), who discuss the basic properties of hardwood barks that could be important in the manufacture of any fibrous product. This was a progress report showing results for 16 pulpwood species work is in progress on 16 additional species. Measured were such bark factors as specific gravity, extractives content, strength, toughness, reaction to hammermilling, and ash content. [Pg.262]


See other pages where Species measured is mentioned: [Pg.379]    [Pg.49]    [Pg.7]    [Pg.12]    [Pg.283]    [Pg.670]    [Pg.332]    [Pg.67]    [Pg.34]    [Pg.343]    [Pg.201]    [Pg.34]    [Pg.41]    [Pg.315]    [Pg.168]    [Pg.103]    [Pg.434]    [Pg.626]    [Pg.66]    [Pg.819]    [Pg.21]    [Pg.475]    [Pg.134]    [Pg.384]    [Pg.69]   
See also in sourсe #XX -- [ Pg.202 ]




SEARCH



Aircraft nitrogen species measurements

Challenges nitrogen species measurements

Distributed diagnostics species distribution measurement

Excited flame measurements, species

Measurement specificity, nitrogen species

Multiple species measurements

Optical measurement methods, chemical species

Reactive surface intermediate species measurement

Remote measurements, nitrogen species

Species Identification and Measurement

Species distribution, measurement

Species measurement methods

Surface sites, nitrogen species measurement

The Activity Coefficient of a Single Ionic Species Cannot Be Measured

© 2024 chempedia.info