Reverse injection

This analytical method determines levels of major oxanilate and sulfonate soil metabolites of acetochlor, alachlor, and metolachlor in groundwater and surface water. The method consists of analysis of environmental samples by direct aqueous injection reversed-phase LC/MS/MS. 

A.G. Fogg, A.E. Davies, Reverse-flow injection or reagent injection Normal flow-injection, reverse flow-injection and single-boundary measurements, Analyst 117 (1992) 1055. 

To this end, loop-based injection is preferred and the sample aspiration tube (Fig. 6.9) behaves as a sampling probe, as demonstrated in the landmark work of Thomsen et al. who determined reactive silicate in coastal waters during a cruise from Monterey Bay to San Francisco Bay in the USA [3]. The sample was continuously aspirated from a water layer about 2 m below the sea surface and a situation of "infinite sample volume" was attained in the main channel of a shipboard reagent injection (reversed flow) flow injection system. A reagent aliquot was injected into the flowing sample every 45 s and the resulting coloured zone was quantified by spectrophotometry. The height of the recorded peak was directly related to the reactive silicate concentration at the specified location and depth. 

Reactant and energy injection strategy, as one-shut (batch), continuous pulsed injection, reversed flow, staged injection, and use of a membrane. 

The bipolar junction transistor (BIT) consists of tliree layers doped n-p-n or p-n-p tliat constitute tire emitter, base and collector, respectively. This stmcture can be considered as two back-to-back p-n junctions. Under nonnal operation, tire emitter-base junction is forward biased to inject minority carriers into tire base region. For example, tire n type emitter injects electrons into a p type base. The electrons in tire base, now minority carriers, diffuse tlirough tire base layer. The base-collector junction is reverse biased and its electric field sweeps tire carriers diffusing tlirough tlie base into tlie collector. The BIT operates by transport of minority carriers, but botli electrons and holes contribute to tlie overall current. 

The in situ combustion method of enhanced oil recovery through air injection (28,273,274) is a chemically complex process. There are three types of in situ combustion dry, reverse, and wet. In the first, air injection results in ignition of cmde oil and continued air injection moves the combustion front toward production wells. Temperatures can reach 300—650°C. Ahead of the combustion front is a 90—180°C steam 2one, the temperature of which depends on pressure in the oil reservoir. Zones of hot water, hydrocarbon gases, and finally oil propagate ahead of the steam 2one to the production well. 

The oil 2one is fairly cool, and in a viscous oil reservoir this can result in Htde oil movement (Uquid blocking). Reverse combustion, in which oil ignition occurs near the production well, can avoid this problem. The combustion 2one moves countercurrent to the flow of air from the injection well. Oil flows through heated rock and remains mobile. Reverse combustion requires more air and consumes more oil than forward combustion. 

The USP recognizes three forms of water for parenteral dosage forms. Water for injection is prepared by reverse osmosis or distillation, which... 

A notable difference between the newer large machines and the somewhat smaller units is the use of multiple, reverse-flow can combustors configured annulady. Because the individual cans are relatively small, they reportedly lend themselves well to laboratory experimentation with various fuel types, including reduced-heat value synfuels (see Fuels, synthetic). A dry, low NO version of the can combustors has been developed for both gas and hquid fuel firing. NO emissions can reportedly be held below 25 ppm when firing gas fuel. By employing water injection, NO emissions can be held below 60 ppm for oil-fired units. 

As Figure 10 shows, the n—p—n bipolar junction transistor (BJT) may be regarded as two back-to-back p—n junctions separated by a thin base region (26,32,33). If external voltages are applied so that the base-emitter (BE) junction is forward biased and the base-coUector (BC) junction is reverse biased, electrons injected into the base from the emitter can travel to the base-coUector junction within their lifetime. If the time for minority carrier electrons to... 

We proposed using MLC for assay of azithromycin in tablets and capsules. As alternative conventional reversed-phase HPLC method MLC was used for analysis of Biseptol (sulfamethoxazole and trimethoprim) tablets and injection. The MLC was proposed to assay of triprolydine hydrochloride and pseudoephedrine hydrochloride in tablets as alternative normal-phase HPLC method described in USP phamiacopoeia. 

The double opposed seal is used in applications where a zero process leakage is mandated. The seal consists of two seal faces, with the process side seal reversed. An inert gas is injected between the two seals at a positive differential over the process gas pressure. A small amount of the inert gas leaks into the process. The process must be able to accept the contamination of the buffer gas for this seal to be used. 

For the double-opposed seal, normally an inert gas is injected between the two opposed seals. This gas is pressure controlled to maintain a differential pressure higher than the process side pressure. The supply to this seal is critical because a failure will permit the differential pressure across the outer seal to reverse, which will result in a seal failure. This seal arrangement usually incorporates a buffer to the process side of the... 

F11 Rotary Kiln with Liquid Injection Unit R24 Metals Recovery - Reverse Osmosis... 

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