Leaching differential

Chittoor J.M. Leach J.E. White F.F. (1997) Differential induction of a peroxidase gene family during infection of rice by Xanthomonas oryzae po. oryzae // Mol Plant Microbe Inter. V. 10. P. 861-871. 

The bulk of this paper will be concerned with the prospects of Ji-nitroso compound formation in the environment, and with environmental behaviors of selected nitroso compounds, as best we can describe or predict them from experimental work completed thus far. Obviously, once in the environment, a compound will to a large extent be subject to the same conditions whether it was formed there or introduced as a pesticide contaminant, and in this manuscript no attempt to differentiate between the two modes of introduction has been made. Such distinctions could, however, influence the location of a compound in the environment—say on a plant or soil surface if sprayed with a pesticide, admixed with soil if transported by leaching, etc., and some of the experiments cited will have been conceived with one or the other of the introduction modes in mind. 

It is important to differentiate between the two different types of sorption/ desorption tests (i. e.,batch and column-leaching), and the sorption characteristics determined from one should not be confused with the other. Sorption isotherms obtained with batch equilibrium tests are applied mainly to solid suspensions. The physical model, assumed with this situation, is one of a completely dispersed solid particle system, where all solid particle surfaces are exposed and available for interactions with the contaminants of concern. In contrast, column-leaching tests are performed with intact solid samples, and the sorption characteristics obtained from them are the results of contaminant interactions with a structured system where not all-solid particle surfaces are exposed or available for interactions with the contaminants. 

There are a number of methods for determining the chemical durability of waste forms. Different tests determine either the differential leach rate of individual constituents (in g-m 2-d ) or the cumulative leaching (in g-m 2, or mol% or wt%). The differential leach rate is given by... 

Nasraoui, M., Toulkeridis, T., Clauer, N. Bilal, E. 2000. Differentiated hydrothermal and meteoric alterations in the Lueshe carbonatite complex (Democratic Republic of Congo) identified by a REE study combined with a sequential acid-leaching experiment. Chemical Geology, 165, 109-132. 

In TCM, hypothyroidism is considered a syndrome of Spleen-Qi deficiency and accumulation of dampness or damp-phlegm in the body. Although western drugs may help to keep thyroid hormone levels normal, symptoms such as tiredness, coldness, weight gain and constipation may still exist. In the differentiation of the syndrome, many patients still show signs of Spleen-Qi deficiency and accumulation of dampness in the body, therefore treatment should be given to tonify the Spleen-Qi, activate Qi movement and leach out dampness. 

Leach rate measurements have been made on several waste forms, using the NAA technique. Some results are presented here as examples of the application of this method. Simulated wastes used in these studies consisted of two types of granules obtained from Battelle Pacific Northwest Laboratories. The differential leach rates of the bulk waste matrix were calculated with the equation ... 

Another theory which at this period had been developed to an unwarranted extent, and which also became a target for Boyle s logical analysis, was that of acids and alkalies. We have seen the extent to which, under the authority of Van Helmont, Sylvius de le Boe, and Tachenius, these concepts had been carried. It may be recalled that the ancients did not differentiate sharply between the acid of vinegar, acetum, and other acid juices. The Arabic word alkali, was derived from Kali, the name of a plant (a glass-wort) the ashes of which were leached to obtain the salt... 

The profile development process is therefore marked by differential movement of constituents some, such as salts of potassium or sodium may be leached completely... 

Fj = Fe = 0. A leach stage could be simulated by combining the various rate equations and equilibrium relationships with the material balance, Eq. 9 for each component. The result would be a very complex set of differential equations. 

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