Abstract: An improved diaphragm valve, particularly adapted for applications at high pressures and in applications in which low dead volume is required. The valve has a diaphragm which is formed of a halogenated hydrocarbon polymer of a compression strength sufficient to avoid non-recoverable extrusion of the diaphragm. Use of such a valve totally avoids the work-hardening problem encountered in use of valves using metal diaphragms.
Abstract: Esters are prepared by reaction of acyl halides and alcohols or hydroxyalkyl esters and acid halides in the presence of a tertiary amine and polar aprotonic solvents. Bis(2-methacrylatoethyl) phthalate is prepared by the reaction of phthaloyl chloride with 2-hydroxyethyl methacrylate in pyridine and acetone. Bis-phenol-A-bis(2-methacrylatoethyl)ether is prepared from 2,2-bis[4-(2-hydroxyethoxy)phenyl]-propane and methacryl chloride in acetone.
September 19, 1973
Date of Patent:
January 10, 1978
Donald G. Stoffey, Jan Alexander Orlowski
Abstract: Dental compositions for sealing margins between tooth structures and amalgam restorations therein, the compositions comprising (a) an alkylene glycol dimethacrylate and/or its oligomer, (b) a polymerization initiator, (c) a polymerization accelerator and (d) a secondary monomer additive; and process for sealing the margins with the compositions.
Abstract: In the salting of vegetables, such as cucumbers, control of fermentation using brine acidity as the monitor and continually and rapidly determining brine acidity with tris(hydroxymethyl)aminomethane as a standard.
May 11, 1972
Date of Patent:
November 23, 1976
The United States of America as represented by the Department of Agriculture
Thomas A. Bell, John L. Etchells, Raymond E. Kelling, James L. Olsen
Abstract: A composition of matter comprising a polymeric reaction product of a hydroxy terminated butadiene prepolymer having an average molecular weight of about 400 to 25,000 and containing 1 to 3 hydroxyl groups per molecule and a polyisocyanate reactant present in an amount to provide from 100 to 1200 percent excess isocyanate groups to hydroxyl groups or active hydrogen sites, and from 1 to 70 percent by weight of a compound containing a fluoride ion. In another, and preferred aspect of the invention, the polyisocyanate reactant is present in an amount to provide from 1.5 to 2.7 isocyanate groups for each hydroxyl group or active hydrogen site, the composition containing an aromatic polyol, such as N,N-bis(2-hydroxypropyl) aniline, and wherein the aromatic polyol comprises at least 42 percent but not more than 60 percent of the hydroxyl components. The compositions are especially useful as dental fissure sealants and as means of applying a fluoride to a tooth surface.
Abstract: A body electrode suitable for sensing bioelectrical potentials and adapted to be electrically connected to an external electrically responsive member, the body electrode including a stainless steel electrode and an aqueous alkali metal sulfate electrolyte; and methods of accurately receiving and transmitting for monitoring and diagnostic purposes small electrical voltages generated in the body.
Abstract: A molding apparatus for thermoforming plastic sheet material having upper and lower matching molding blocks, each molding block having a thin rigid shell. The shell has a die cavity therein with the exposed face of the shell defining the die cavity surface. A porous body of metallic filler material is contained within the central portion of each molding block and is in contact with the inner surface of the rigid shell. Inlet and outlet means are provided for circulating a coolant fluid through the central portion of each molding block.