Tracers sodium

Schiesser and Lapidus (S3), in later studies, measured the liquid residencetime distribution for a column of 4-in. diameter and 4-ft height packed with spherical particles of varying porosity and nominal diameters of in. and in. The liquid medium was water, and as tracers sodium chloride or methyl orange were employed. The specific purposes of this study were to determine radial variations in liquid flow rate and to demonstrate how pore diffusivity and pore structure may be estimated and characterized on the basis of tracer experiments. Significant radial variations in flow rate were observed methods are discussed for separating the hydrodynamic and diffusional contributions to the residence-time curves. 

Evidence of the groundwater tracer sodium bromide was found in water from waste trench 27 and several inert atmosphere wells. Changes in bromine concentrations were observed in water from waste trench 27, the experimental trench, and inert atmosphere wells, indicating that there is some communication by groundwater flow between these locations (Table II). Bromine concentrations in water samples from waste trench 27 were quite low prior to the construction of the experimental trench. Following trench... 

Fig. 3 shows the results of measurements of the total inward tracer sodium flux (open circles) resulting from voltage-clamped depolarising pulses of about 3 ms duration as a function of the absolute membrane potential during the pulse. (Potential is referred to the external solution as ground. Flux is plotted upward but inwardly directed currents would be negative quantities.)... 

Fig. 3, Comparisons between the measured tracer sodium flux (O) and electrically measured ionic flux during the early transient current following a depolarising voltage-clamp pulse of about 3 ms duration ( ). Axons from Dosidicus gigas internally perfused with 550 mK KF, pH 7.3 immersed in K-frec artificial sea water. Temp. 17°C. Control experiments with tetrodotoxin were used (u.sing the same axon) to subtract current components due to potassium. (Used with permission from Atwater el al. [I7J.)...

Sodium cyanide is also used as a radioactive tracer, sodium [ " C]-cyanide (Kirk-Othmer, 1996). In the United States, it is used as an active ingredient in a predator collar around a sheep s neek to poison coyotes (Kirk-Othmer, 1982b). 

The radioactive isotopes available for use as precursors for radioactive tracer manufacturing include barium [ C]-carbonate [1882-53-7], tritium gas, p2p] phosphoric acid or pP]-phosphoric acid [15364-02-0], p S]-sulfuric acid [13770-01 -9], and sodium [ I]-iodide [24359-64-6]. It is from these chemical forms that the corresponding radioactive tracer chemicals are synthesized. [ C]-Carbon dioxide, [ C]-benzene, and [ C]-methyl iodide require vacuum-line handling in weU-ventilated fume hoods. Tritium gas, pH]-methyl iodide, sodium borotritide, and [ I]-iodine, which are the most difficult forms of these isotopes to contain, must be handled in specialized closed systems. Sodium p S]-sulfate and sodium [ I]-iodide must be handled similarly in closed systems to avoid the Uberation of volatile p S]-sulfur oxides and [ I]-iodine. Adequate shielding must be provided when handling P P]-phosphoric acid to minimize exposure to external radiation. 

If the source fingerprints, for each of n sources are known and the number of sources is less than or equal to the number of measured species (n < m), an estimate for the solution to the system of equations (3) can be obtained. If m > n, then the set of equations is overdetermined, and least-squares or linear programming techniques are used to solve for L. This is the basis of the chemical mass balance (CMB) method (20,21). If each source emits a particular species unique to it, then a very simple tracer technique can be used (5). Examples of commonly used tracers are lead and bromine from mobile sources, nickel from fuel oil, and sodium from sea salt. The condition that each source have a unique tracer species is not often met in practice. 

Barium nitrate is prepared by reaction of BaCO and nitric acid, filtration and evaporative crystallization, or by dissolving sodium nitrate in a saturated solution of barium chloride, with subsequent precipitation of barium nitrate. The precipitate is centrifuged, washed, and dried. Barium nitrate is used in pyrotechnic green flares, tracer buUets, primers, and in detonators. These make use of its property of easy decomposition as well as its characteristic green flame. A small amount is used as a source of barium oxide in enamels. 

These reactions are useful because they run under mild conditions, use inexpensive or easily recoverable starting materials, and have short reaction times. The major problem in purification is the separation of the sodium pyridone sulfonate from excess sodium sulfite, sodium bromide, and sodium bromoalkyl sulfonate. However, these latter compounds usually would not interfere with the use of the pyridone sulfonate as a water tracer. From a practical point of view, the pyridone sulfonates need not be purified, but can be used directly. A modified synthetic procedure involves the treatment of the pyridone sodium salt with a tenfold excess of a,iu-dibromoalkane in acetonitrile, followed by removal of the excess dibromide by vacuum distillation. The resulting product is treated with an excess of sodium sulfite in aqueous ethanol. Evaporation of the solvent yields a useful tracer. Procedures given in the experimental section were... 

Yeo, A.R., Yeo, M.E., Caporn, S.J.M., Lachno, D.R. Flowers, T.J. (1985). The use of C-ethane diol as a quantitative tracer for the transpirational volume flow of water, and an investigation of the effects of salinity upon transpiration, net sodium accumulation and endogenous ABA in individual leaves of Oryza sativa L. Journal of Experimental Botany, 36, 1099-109. 

To mark the displacement front, 150 ppm of sodium iodide was incorporated in the surfactant micellar slug. This tracer can easily be detected in effluents with a UV detector at 229 nm. 

To establish the well drainage boundaries and fluid flow patterns within the TFSA-waterflood pilot, an interwell chemical tracer study was conducted. Sodium thiocyanate was selected as the tracer on the basis of its low adsorption characteristics on reservoir rocks (36-38), its low and constant background concentration (0.9 mg/kg) in produced fluids and its ease and accuracy of analysis(39). On July 8, 1986, 500 lb (227 kg) of sodium thiocyanate dissolved in 500 gal (1.89 m3> of injection brine (76700 mg/kg of thiocyanate ion) were injected into Well TU-120. For the next five months, samples of produced fluids were obtained three times per week from each production well. The thiocyanate concentration in the produced brine samples were analyzed in duplicate by the standard ferric nitrate method(39) and in all cases, the precision of the thiocyanate determinations were within 0.3 mg/kg. The concentration of the ion in the produced brine returned to background levels when the sampling and analysis was concluded. 

TFSA-WATERFLOOD PILOT. A 36 acre (1.14 x lO m2) TFSA-waterflood pilot was recently conducted in the Torrance Field in the Los Angeles Basin of Southern California. To characterize the fluid floi patterns within the pilot, an interwell chemical tracer study was conducted with sodium thiocyanate. Results of the tracer study are shown in Table IV. Only 61.6 % of the injected tracer was recovered in the produced fluids, indicating that as much as 38.4 % of the injected fluids were flowing out of the pattern. Furthermore, since only 1604 bbl/d (255 m3/d) of brine was injected into the pattern, as much as 75.9 % of the total fluids produced by pilot wells were from outside the pattern. 

Elution volume calibrations were performed using radioactive tracers of the rare earth elements and 133Ba, with atomic-absorption or flame-emission analysis of iron, sodium, potassium, calcium, and magnesium. As shown in Fig. 5.14, any barium added to the second columns is eluted at the start of the light rare earth element fraction . To ensure barium removal the sample can be put through the first column again. 

Rhodes et al. (1991) conducted RTD measurements to study longitudinal solids mixing in a circulating fluidized-bed riser by pulse-injection of a sodium chloride tracer. 

The first and second tracer tests used 20 kgs of sodium flourescein dye in March 1998 and 1 curie of T31 in December 1998. The results of these tests... 

Very few direct measurements of the reaction of surface silanol groups on quartz have been reported. This is apparently caused by the small effects due to the limited surface areas available. Adsorption of sodium ions on quartz was measured by radioactive tracer techniques by Gaudin et al. (293). Saturation was achieved at high pH (>10) and sodium ion concentrations above 0.07 Jlf. The calculated packing density of silanol groups was 4.25/100 A. Goates and Anderson (294) titrated quartz with aqueous sodium hydroxide and alcoholic sodium ethylate. The occurrence of two types of acidic groups was reported. 

Ng and Assirelli have carried out a mixing study in batch stirred vessels with working volumes of 3 L to 20L using a fiber-optic UV-vis monitoring technique. Bromophenol blue sodium salt was used as a non-reactive tracer. The results on traditional Rushton turbines and 45° angled pitched blade turbines showed good agreement with a typical conductivity technique and a correlation proposed in literature. 

To obtain a true k in MEEKC, it is important to trace the migration of the pseudostationary phase accurately. Sudan III, timepidium bromide, and quine, which have generally been used as tracers for micelles in MEKC, could not be employed as tracers for microemulsions consisting of sodium dodecylsulfate salt (SDS) or cetyltrimethylammonium bromide (CTAB), n-butanol and heptane (12). An iteration method based on a linear relationship between log k and the carbon number for alkylbenzenes (13) seems to provide a reasonable value of the migration time of the microemulsions. Dodecylbenzene shows a migration time larger than the value calculated by the iteration method and those of other hydrophobic compounds, such as phenanthrene, fluoranthrene, and Sudan III (Table 1). Methanol and ethanol were used as tracers for the aqueous phase. 

Also called vapour-phase interferences or cation enhancement. In the air-acetylene flame, the intensity of rubidium absorption can be doubled by the addition of potassium. This is caused by ionization suppression (see Section 2.2.3), but if uncorrected will lead to substantial positive errors when the samples contain easily ionized elements and the standards do not. An example is when river water containing varying levels of sodium is to be analysed for a lithium tracer, and the standards, containing pure lithium chloride solutions, do not contain any ionization suppressor. 

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