Air-liquid

The transfer of Langmuir films from the air-liquid surface to a solid substrate has come to be known as Langmuir-Blodgett deposition, after its developers [130, 131]. The solid substrates are usually hydrophilic surfaces such as... 

Liquid metals, however, present several disadvantages. Their weights must be considered with regard to equipment design. Additionally, Hquid metals are difficult to contain and special pumps must be used for system safety. Alkali metals react violentiy with water and bum ia air. Liquid metals also may become radioactive whea used for cooling auclear reactors (qv). 

The principal international producers and distributors of nitrogen are L Air Liquide S.A. (France), The BOC Group Pic (U.K.), Air Products and Chemicals, Inc. (U.S.), and Praxair, Inc. (U.S.). There are many other smaller regional producers. 

Potassium superoxide is utilized primarily ia respiratory support equipment. The material is produced ia the United States (Gallery Chemical Company), France (Air Liquide), and China. 

Calcium peroxide is made by EMC, L Air Liquide, Nippon Peroxide (Japan), Shimakyo Chemical (Japan), Solvay Deutschland, Solvay Interox (United Kingdom), and Tomita Seiyaku (Japan). Trade names used for calcium peroxide are Calper, IXPER 60 C, IXPER 75 C, PermeOx, and Trap2ene. The world market for calcium peroxide ia 1992 was about 2000 t. The U.S. prices ia 1994 were, for the food-grade (75% Ca02), 3.97/kg and for the technical grade (60%), 2.97—3.30/kg. 

This product has been assigned UN No. 1449 and should be transported in accordance with international transport regulations pertaining to Class 5.1, oxidizing substances. It is made by Solvay Deutschland, which uses the trade name IXPER 90 B, and by L Air Liquide. The U.S. price in 1994 was 12/kg the French price was Fr. 75/kg. 

The world market in 1993 was about 450,000 t. Sodium peroxoborate is made commercially by Atochem, Ausimont, Caffaro, Degussa, Eka Nobel, Foret, L Air Liquide, Solvay Interox (Belgium, Italy, Germany, United Kingdom, United States), and Treibacher Chemische Werke. The U.S. price in 1994 was in the range 1.32—1.43/kg, the German price was DM 1.35—1.60/kg ( 0.78—0.92/kg). 

Technical data. Air Liquide America, Walnut Creek, Calif., 1994. 

U. Single water drop in air, liquid side coefficient / jy l/2 ki = 2 ), short contact times / J 1 lcontact times dp [T] Use arithmetic concentration difference. Penetration theory, t = contact time of drop. Gives plot for k a also. Air-water system. [lll]p.. 389... 

FIG. 15-21 Continuous extraction of n-hiitylamine from kerosine into water. T = 1.23 ft, Z = 1.56 ft, no air-liquid interface, impellers centered, Vr/Ve X 1-57, residence time X 1.08 min. To convert feet to meters, multiply hy 0.3048 to convert inches to centimeters, multiply hy 2.54 and to convert horsepower to kilowatts, multiply hy 0.746. [Overcashiet Kingsley, and Olney, Am. Inst. Chem. Eng. J., 2, 529 (1.956), with permission.]... 

Consider the simple initial condition t = 0 where the sohd concentration (t),o is constant across the entire shiny domain ix < r < rb where / l and l b are, respectively, the radii of the shiny surface and the bowl. At a later time t > 0, three layers coexist the top clarified layer, a middle shiny layer, and a bottom sediment layer. The air-liquid interface remains stationaiy at radius / l, while the hqiiid-slurry interface with radius i expands radiaUy outward, with t with i given by ... 

A special form of crevice attack can occur at a waterline or at the edges of water droplets. At the water surface, a meniscus region is present where surface tension causes water to climb up the metal surface it contacts. In effect, a crevice is formed between the air-liquid and liquid-metal interface at the meniscus. Oxygen concentration is high at the meniscus due to the greater accessibility of this region to the air. The meniscus region becomes cathodic to the adjacent metal surface. Corrosion occurs just below the meniscus, and chloride, if present, is... 

Because STM measures a quantum-mechanical tunneling current, the tip must be within a few A of a conducting surface. Therefore any surface oxide or other contaminant will complicate operation under ambient conditions. Nevertheless, a great deal of work has been done in air, liquid, or at low temperatures on inert surfaces. Studies of adsorbed molecules on these surfaces (for example, liquid crystals on highly oriented, pyrolytic graphite ) have shown that STM is capable of even atomic resolution on organic materials. 

LNG is predominantly methane, not toxic but flammable in air. Liquid below -161 ° C is delivered to the methane terminal in shiploads of 12,000 tonnes and is transferred into either four in-ground tanks, each of about 20,000 tonnes capacity or eight above-ground tanks, six w ilh 4,000 tonnes capacity and two with 1,000 tonnes capacity. The LNG is refrigerated below the boiling point of the gas mixture. 

Air Liquide Group (France) Air Products Chemicals) Aldrich Chemical Atofina Chemicals Atomergic Chemetals (France) BOC Gases (UK)... 

Advance Research Chemicals Air Liquide Group (France)... 

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