Tracers, analysis

Linearity with respect to the tracer analysis, that is, the magnitude of the response at the outlet is directly proportional to the amount of tracer injected. 

There are a number of Physical Methods available but of all the Physical Methods, tracer analysis using C14, H3 or S35- labelled initiators or other substances has received considerable attention. However, this method is incapable of giving results specific to the actual functional group and is highly susceptible to interference by absorbed radioactive impurities. It is moreover hazardous, expensive and needs sophisticated apparatus. 

Thus, a multibiomarker tracer analysis of both water-soluble and hydrophobic organic compounds in various environmental samples using the GC-MS analytical method is useful. The saccharides, i.e. monosaccharides, disaccharides, anhydrosaccharides, and polyols (reduced sugars) are an important class of water-soluble compounds to be considered as environmental tracers. 

Tracer Analysis. This method is readily performed with radioactive isotopes because their ease of detection by measurement of their... 

Closely related to tracer analysis is the method of isotopic dilution analysis. Here, instead of checking the effectiveness of a method from known amounts of an element in the sample, and of its radioactive isotope, one knows only the amount of radioactive isotope added, and by precipitating or otherwise separating the total amount of that element present, and then measuring its radioactivity, one determines its amount, and hence the amount present in the original sample. 

Gilardoni S, Vignati E, Cavalli F, Putaud JP, Larsen BR, Karl M, Stenstrom K, Genberg J, Henne S, Dentener F (2011) Better constraints on sources of carbonaceous aerosols using a combined 14C - macro tracer analysis in a European rural background site. Atmos Chem Phys 11 5685-5700. doi 10.5194/acp-ll-5685-2011... 

Covell DG, Berman M, DeLisi C. Mean residence time — Theoretical development, experimental determination, and practical use in tracer analysis. Math. Biosci. 1984 72 213-244. 

Mackas D. L., Denman K. L., and Bennett A. E. (1987) Least squares multiple tracer analysis of water mass composition. J. Geophys. Res. 92(C3), 2907-2918. 

Methanol synthesis from H2/CO2 has been studied so feir in relation to that from H2/C0.[2,3] One of the reasons studied before is due to an interesting phenomenon that an addition of small amoimt CO2 into H2/CO feed improves methanol 5deld significantly in the industrial process.[2] The role of added CO2 was noted. Rozovskii showed by tracer analysis study that carbon species of produced methanol originated from CO2 in the H2/CO feed, suggesting methanol was produced via C02.[4] Recent researches have been aiming at the development of highly efficient catalysts for methanol synthesis for the industrial process. 

A logical next step is the formulation of correlation functions between suspension characteristics (as presently described by a calculated collision efficiency value), specific tank parameters (as presently expressed in terms of the dispersion number, derived from tracer analysis), and solids separation... 

If an absorption phenomenon is occurring, changing the materials of construction of the wetted surfaces could impact the results. The best reactor results (in which the reactor volume based on the tracer analysis most closely matches the geometrically calculated reactor volume) were attained with stainless steel materials of constmction. The injector loops, tubing from the injectors to the mixing tee, and the reactor were all changed to stainless steel materials of construction of equivalent volumes. The flat top experiments were repeated for this configuration Fig. 13.10 shows the results. 

The water property below the 3,500 m depth in the SCS is similar to that of the Philippine seawater in the layer from 1,900 m to 2,000 m, which shows that the bottom water in the SCS originates from the western Pacific. The same result could also be obtained from chemical tracer analysis. Using a box model, Han (1998) suggested the renewal time of the deep-water below 2,000 m is about 76 years. Fang and Wei (2002) pointed out that the circulation between Pacific Ocean and Indian Ocean through the SCS is a branch of the throughflow. From their numerical results, the annual mean transport is about (4 1.5) Sv, and the renewal time of the SCS water is (40 15) years. All the... 

Rosenblatt J, Chinkes D, Wolfe M, Wolfer RR. Stable isotope tracer analysis by GC-MS, including quantification of isotopomer effects. Am J Physiol 1992 263 E584—E596. 

Etching, and radioactive tracer analysis of the remaining specimen, were used to measure the diffusivity. The latter coefficients could be varied, by a factor of up to 1000, by varying the partial pressures of the components in the ambient. At 800C, and a Se mole fraction of 10" , the Se diffusivity could be described by ... 

The methods of p-n junction measurement and radioactive tracer analysis were used to study the diffusion of P in single crystals for various impurity surface concentrations. The data could be described by ... 

Radioactive tracer analysis is based on the simple proportionality between the mass of analyte x and the radioactivity A initially added to the sample ... 

Mills, P. L., W. P. Wu and M. P. Dudukovic. Tracer Analysis in Systems with Two-Phase Flow. AIChE Journal 25 (1979) 885. 

Reservoir coimectivity is important to sweep efficiency in all phases of production. How efficiently a formation s pore spaces are coimected is determined through tracer analysis, where chemical or radioactive tracers are introduced at injection and monitored at production wells. The idea is simple the more tracers obtained at a producer, the better the connectivity between the injectors and it. In reservoir simulation, the oilfield s permeability and porosity distributions are determined, often by trial and error, and more than likely nonuniquely, by history matching with production and well test data. In singlephase flow reservoirs, steady-state production profiles are completely determined by the pressure equation and Darcy s law, neither of which depends on porosity. In well testing, pressure buildup and drawdown depend on porosity and compressibility, factors that do not directly enter in steady-state production. Empirical tracer tests provide further information porosity, inferred from tracer travel times, enters in steady flows where compressibility is unimportant. These three flow tests therefore provide good independent check points that are essential to good reservoir description. 

Reaction mechanisms of acetone aldol condensation over MgO and La20s were studied using deuterium as a tracer. Analysis of the isotopic distributions of the product and reactant revealed that the slow step is involved in Step II in accordance with homogeneous systems. 

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