Absorption agents

Levodopa degraded in gut prior to reaching sites of absorption. Agents that alter gastrointestinal motility may alter degree of intraluminal degradation. Anti-parkinsonism effect of levodopa susceptible to inhibition by other drugs. 

Flo. 34. Mbssbauer spectrum of tetramethyl tin before and after chemisorption on y-AI,03. N is the count rate of the y quanta at the given value of V N0 is the count rate of the y quanta when the absorption agent is stationary, (a) Tetramethyl tin, (b) tetramethyl tin adsorbed on y-AI203. Zero velocity is with respect to Sn02- Figure according to Karasev et al. (230). 

Heinemann, T., Pietruck, B., Kullak-Ublick, G., and von Bergmann, K. 1988. Comparison of sitosterol and sitostanol on inhibition of intestinal cholesterol absorption. Agents Actions... 

Applications Potassium hydroxide is utilized in the manufacture of other potassium compounds (potassium carbonate, potassium phosphates e.g. tetrapotassium pyrophosphate, potassium permanganate, potassium bromate, potassium iodate, potassium cyanide etc.), of dyes, special soaps and battery liquids. It is also used in photographic developers, in glass manufacture and as a drying and absorption agent. In many of these applications its use is declining. 

Magox . [Premier Services] Magnesium oxide adsorption, absorption agent and scavenger for plastics, rubber industries, chemical neutralization. 

Schaarschmidt, A., H. Hoffmeier, and P. Nowak Applicability of absorption agents for removing poisons from tobacco smoke Chem. Zeit. 56 (1932) 911-913. Schaller, K.H., G. Triebig, and B. Beyer Determination of formaldehyde in tobacco smoke Investigations under experimental and field conditions Zbl. Hyg. Umweltmed. 189 (1989) 103-110. 

Inhibition of Lipid Absorption - Agents which decrease the absorption of dietary lipids specifically by inhibiting pancreatic lipase may be suitable for the treatment of obesity. The reduced rate of lipid absorption produced by fenfluramine in rats is probably due to an inhibition of pancreatic lipase. The structural features of a series of phenethylamines, including fenfluramine, required for lipase inhibition have been described using partially purified rat and human pancreatic lipase. Pluronic L-101, a hydrophobic surfactant is a potent inhibitor of pancreatic lipase vitro and reduces body weight gain and carcass lipid after chronic administration to rats. Fecal excretion of dietary lipid is enhanced by Pluronic L-101, thus supporting its action as a lipase inhibitor. 

In most cases absorption units consist of an absorption step and a regeneration step. Regeneration enables the internal recycling of the absorption agent as shown in Fig. 5.3-1. 

This agent is oily and does not evaporate quickly, thus it is primarily a skin or eye absorption agent. When sprayed on environmental surfaces, it will last longer than 24 hours (persistent). However, under certain conditions it may be inhaled. VX is very potent. The LD50 of victims with skin exposure to VX is only 10 mg (1 drop). 

Gas scrubbers are operated in countercurrent flow and are typically equipped with structured packings or trays. The degree of removal of gaseous components depends on their solubility in the liquid absorption agent and thus on pressure and temperature, and on the liquid-to-gas ratio, which is defined as the ratio of the carrier fluid flow to the gas flow. For the design of an absorption column, the McCabe-Thiele approach is used, as already examined for distillation in Section 3.3.2.2. 

The vapor pressure of the absorption agent and thus a transfer into the gas phase is negligible, and the flow of liquid (without absorbed gas), h, is constant. 

Ya is the loading of the carrier gas with the absorbed gaseous component A (molmol ), and Xa is the loading of the liquid absorption agent (molmol ). Note that in contrast to distillation, where the molar content in the total vapor (Pa) and in the total liquid phase (%a) is used, loadings are typically used for absorption. However, the differences of Ya and Xa compared to >a and Xa are negligible if the content of the absorbed component is small. 

Contrary to distillation, only one single operating line is needed for design of the absorption column. The gas enters the column at the bottom and the absorption agent is supplied on top, so we do not have to consider two sections with different flow rates of gas and liquid as in case of distillation. Hence in total, we need two lines, the equilibrium and the operating line. 

In a flue-gas desulfurization process from Mitsubishi Heavy Industries (MHI), manganese dioxide (Mn02) is the absorption agent. The final product is ammonium sulfate (NH4)2S04, which is an excellent fertilizer. MHI claims better than 90% removal of SOx with this process. 

Desorption the reverse process of absorption agent will be removed from the surface (off gassing or out gassing)... 

According to this equation, it can be seen that the lower the osmotic pressure of ions (the higher the ionic concentration of electrolyte solution) the lower the ability to absorb water. When gels are used in feminine products or as water absorption agents, it is important to select application-specific gels. For feminine products, thirmess and dryness are required. These requirements are accomplished by using absorbent layers [3-5]. 

The moisture absorption eapability of a polyacrylate-type superabsorbent polymer is lower than that of inorganic moisture absorption agents, such as silica gel. In addition, moisture absorption significantly increased as the water vapor pressure increased. This is due to the excellent water absorption capability of the superabsorbent polymers. Hence, superabsorbent polymers are especially useful for moisture absorption at high humidity. Furthermore, by adding a moisture absorption agent, such as calcium chloride, a eompound that has lower saturation... 

Anghilerl, L. J. (NP-14263) Sliver Halides as Absorption Agents of Radio-iodine. Report No, 116. (Argentina Comision Nacional de Energia Atomica, Buenos Aires). 1964. 9 p. Dep. (mn). 19 5759... 

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