Potassium first limit

Further kinetic measurements of the type made by Kowalsky were carried out by Semenov and co-workers [61] using a vessel washed with hydrofluoric acid and coated with potassium tetraborate. The first limits in this vessel ranged from 0.16 to 0.07 torr between 460 and 600 °C. It was thus possible to penetrate much further into the explosion region than peviously, while at the same time keeping the pressure and reaction velocity low and so avoiding the heat dissipation problem. Initial pressures ranging from 0.3 to 1.2 torr were used. The results, as did those of... 

Sodium and potassium hydroxides. The use of these efficient reagents is generally confined to the drying of amines (soda lime, barium oxide and quicklime may also be employed) potassium hydroxide is somewhat superior to the sodium compound. Much of the water may be first removed by shaking with a concentrated solution of the alkali hydroxide. They react with many organic compounds (e.g., acids, phenols, esters and amides) in the presence of water, and are also soluble in certain organic liquids so that their use as desiccants is very limited... 

Nitroethane. The principal use of nitroethane is as a raw material for synthesis in two appHcations. It is used to manufacture a-methyl dopa, a hypertensive agent. Also, the insecticide 3 -methyl-A/-[(methylcarbamoyl)oxy]thioacetimidate [16752-77-5] can be produced by a synthesis route using nitroethane as a raw material. The first step of this process involves the reaction of the potassium salt of nitroethane, methyl mercaptan, and methanol to form methyl methylacetohydroxamate. Solvent use of nitroethane is limited but significant. Generally, it is used in a blend with 1-nitropropane. 

Potassium carbonate. Solid potassium hydroxide is very rapid and efficient. Its use is limited almost entirely to the initial drying of organic bases. Alternatively, sometimes the base is shaken first with a concentrated solution of potassium hydroxide to remove most of the water present. Unsuitable for acids, aldehydes, ketones, phenols, thiols, amides and esters. Also used for drying gaseous amines and ammonia. 

Anionic polymerization of ethylene oxide by living carbanions of polystyrene was first carried out by Szwarc295. A limited number of methods have been reported in the preparation of A-B and A-B-A copolymers in which B was polystyrene and A was poly(oxyethylene)296-298. The actual procedure was to allow ethylene oxide to polymerize in a vacuum system at 70 °C with the polystyrene anion initiated with cumyl potassium in THF299. The yields of pure block copolymers are usually limited to about 80% because homopolymers are formed300. ... 

During the lifetime of a root, considerable depletion of the available mineral nutrients (MN) in the rhizosphere is to be expected. This, in turn, will affect the equilibrium between available and unavailable forms of MN. For example, dissolution of insoluble calcium or iron phosphates may occur, clay-fixed ammonium or potassium may be released, and nonlabile forms of P associated with clay and sesquioxide surfaces may enter soil solution (10). Any or all of these conversions to available forms will act to buffer the soil solution concentrations and reduce the intensity of the depletion curves around the root. However, because they occur relatively slowly (e.g., over hours, days, or weeks), they cannot be accounted for in the buffer capacity term and have to be included as separate source (dCldl) terms in Eq. (8). Such source terms are likely to be highly soil specific and difficult to measure (11). Many rhizosphere modelers have chosen to ignore them altogether, either by dealing with soils in which they are of limited importance or by growing plants for relatively short periods of time, where their contribution is small. Where such terms have been included, it is common to find first-order kinetic equations being used to describe the rate of interconversion (12). 

In 1899, the nickel-cadmium battery, the first alkaline battery, was invented by a Swedish scientist named Waldmar Jungner. The special feature of this battery was its potential to be recharged. In construction, nickel and cadmium electrodes in a potassium hydroxide solution, it was the first battery to use an alkaline electrolyte. This battery was commercialized in Sweden in 1910 and reached the Unites States in 1946. The first models were robust and had significantly better energy density than lead-acid batteries, but nevertheless, their wide use was limited because of the high costs. 

Renal Effects. Information regarding renal effects of cyanide in humans is limited to one report. Albuminuria was found in a man during the first 2 days after ingestion of 15 mg CN /kg as potassium cyanide in a suicide attempt (Liebowitz and Schwartz 1948). 

Colorimetric analyzers spectrophotometrically measure the increase in color (absorbance) of a solution resulting from contact with a measured volume of air. The absorbance is linearly proportional to the concentration of the colored species, within known limits. Continuous colorimetric analysis of total oxidants is carried out with a solution of neutral buffered potassium iodide (KI). In 1953, Littman and BenolieF developed the first colorimetric oxidant recorder to come into general use. Instruments of this design, using a 20% neutral buffered potassium iodide solution, later changed to 10%, were incorporated into the Los... 

Apart from the development of lithium initiators for the facile polymerization of L-lactide, mainly by our group, there are only a limited number of Na and K initiators known in the literature. Sodium and potassium cations are nontoxic and are essential to life, and we reported the first EDBP-Na complex as efficient initiator for the preparation of PLA [41]. Similarly, potassium EDBP complex [EDBPH-K-(THE)2] 18 has been demonstrated to be an efficient catalyst for the ROP of L-lactide in a controlled fashion, yielding PLAs with expected molecular weights and moderate PDIs (1.29-1.58) [42],... 

A similar chain-growth mechanism was said to occur with the first molybdenum-sulfur-potassium based catalysts of table I (15). For such a chain-growth mechanism, the heavier the average molecular weight of alcohols, the greater the formation of heavy compounds and, more often than not, the lower the alcohols selectivity. Furthermore, in Fischer-Tropsch type catalysts (24,25) diffusion limitations, mostly due to the presence of liquid products condensed in the micro porosity, increase with the size of diffusing molecules. These molecules are capable of... 

It is apparent from Table IV that with nitrobenzene as the oxidation catalyst the ionization-limited rate was not reached even at a nitrobenzene concentration of 2.7M (0.02M fluorene, 0.02M potassium terf-butoxide). The rate of oxidation at the low nitrobenzene concentrations is first-order in nitrobenzene, fluorene, and base. This is consistent with an oxidation rate determined by Reaction 12 and involving an equilibrium concentration of the fluorene anions. 

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