Patents by Inventor Ahmad Dadgar
Ahmad Dadgar has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 5620585Abstract: A process for leaching gold, silver, platinum and palladium wherein an aqueous leaching solution containing bromine and bromide ion contacts a precious metal source to produce an aqueous leachate. A precursor composition for producing an aqueous leaching solution for leaching gold, silver, platinum and palladium. A process for electrogenerating bromine and a process for leaching gold, silver, platinum and palladium wherein bromine is electrogenerated and contacts a precious metal source to produce an aqueous leachate. A process for leaching gold, silver, platinum and palladium wherein bromine is electrogenerated from a solution containing chloride ions and bromide ions.Type: GrantFiled: June 6, 1995Date of Patent: April 15, 1997Assignee: Great Lakes Chemical CorporationInventors: Ahmad Dadgar, Jonathan N. Howarth, Rodney H. Sergent, Nicolai A. Favstritsky, Julie A. McKeown, Dennis W. Borden, Brent M. Sanders, Jane Likens
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Patent number: 5607619Abstract: A process for leaching gold, silver, platinum and palladium wherein an aqueous leaching solution containing bromine and bromide ion contacts a precious metal source to produce an aqueous leachate. A precursor composition for producing an aqueous leaching solution for leaching gold, silver, platinum and palladium. A process for electrogenerating bromine and a process for leaching gold, silver, platinum and palladium wherein bromine is electrogenerated and contacts a precious metal source to produce an aqueous leachate. A process for leaching gold, silver, platinum and palladium wherein bromine is electrogenerated from a solution containing chloride ions and bromide ions.Type: GrantFiled: June 7, 1995Date of Patent: March 4, 1997Assignee: Great Lakes Chemical CorporationInventors: Ahmad Dadgar, Jonathan N. Howarth, Rodney H. Sergent, Nicolai A. Favstritsky, Julie A. McKeown, Dennis W. Borden, Brent M. Sanders, Jane Likens
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Patent number: 5385650Abstract: A process for recovering bromine from an acidic solution containing bromide ion. Electric current is passed through the acidic solution between an anode and a cathode, thereby generating bromine by electrolysis at the anode to produce an electrolyzate containing bromine. Bromine is separated from the electrolyzate as a vapor under negative pressure. The bromide ion solution may be contaminated with organic material. An electrolytic process for producing a hypobromous acid solution. An electrolytic cell.Type: GrantFiled: April 30, 1993Date of Patent: January 31, 1995Assignee: Great Lakes Chemical CorporationInventors: Jonathan N. Howarth, Ahmad Dadgar, Rodney H. Sergent
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Patent number: 5276006Abstract: Aqueous plant cryoprotectant composition containing between about 0.005 and 25 wt. % tetrahydrofurfuryl alcohol, tetrahydrofurfuryl amine or mixtures thereof and method of increasing the resistance of plant tissue to damage caused by freezing conditions comprising applying to the plant tissue surfaces at ambient non-freezing temperatures an aqueous solution containing an effective amount of tetrahydrofurfuryl alcohol, tetrahydrofurfuryl amine or mixtures thereof.Type: GrantFiled: August 13, 1992Date of Patent: January 4, 1994Assignee: Great Lakes Chemical Corp.Inventors: Charles C. Shin, Nicolai A. Favstritsky, Ahmad Dadgar
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Patent number: 5264136Abstract: Methods and compositions for generating stable, residual disinfectants during the ozonization of water, comprising the carrying out the ozonization of water in the presence of bromide ions and an effective amount of a hypobromite ion scavenger possessing imide and/or amide functionality that preferentially converts hypobromite ions to biocidal, ozone-stable derivatives thereof to thereby suppress the catalytic decomposition reaction of ozone with hypobromite ions. The methods and compositions of the present invention are useful for water disinfection and algae control, generally.Type: GrantFiled: October 30, 1992Date of Patent: November 23, 1993Assignee: Great Lakes Chemical CorporationInventors: Jonathan N. Howarth, Ahmad Dadgar, Julie A. McKeown, Rodney H. Sergent
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Patent number: 5223015Abstract: Aqueous plant cryoprotectant composition containing between about 0.005 and 25 wt.% tetrahydrofurfuryl alcohol, tetrahydrofurfuryl amine or mixtures thereof and method of increasing the resistance of plant tissue to damage caused by freezing conditions comprising applying to the plant tissue surfaces at ambient non-freezing temperatures an aqueous solution containing an effective amount of tetrahydrofurfuryl alcohol, tetrahydrofurfuryl amine or mixtures thereof.Type: GrantFiled: October 2, 1989Date of Patent: June 29, 1993Inventors: Charles C. H. Shin, Nicolai A. Favstritsky, Ahmad Dadgar
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Patent number: 4941982Abstract: Clear high density fluids for use as completion, packing and perforation media in oil and gas well formations having high carbonate and/or high sulfate ion concentration are formulated from aqueous solutions of zinc bromide and one or more alkali metal bromides and have densities lying in the range of about 15.0 to 20.5 lb./gal and a pH lying in the range of about 1.0 to 5.5, with the alkali metal bromide being provided in an amount approaching its solubility limit in water.Type: GrantFiled: July 28, 1988Date of Patent: July 17, 1990Assignee: Great Lakes Chemical CorporationInventors: Ahmad Dadgar, Charles C. Shin
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Patent number: 4936910Abstract: Process for recovering gold from a leachate containing AuBr.sub.4.sup.-- comprising contacting the leachate with a quantity of sphagnum peat moss under conditions effective to concentrate the gold on the moss, and thereafter recovering the gold from the sphagnum peat moss.Type: GrantFiled: August 18, 1989Date of Patent: June 26, 1990Assignee: Great Lakes Chemical CorporationInventors: Ahmad Dadgar, Charles C. Shin
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Patent number: 4886543Abstract: Aqueous plant cryoprotectant composition containing between about 0.005 and 25 wt. % tetrahydrofurfuryl alcohol, tetrahydrofurfuryl amine or mixtures thereof and method of increasing the resistance of plant tissue to damage caused by freezing conditions comprising applying to the plant tissue surfaces at ambient non-freezing temperatures an aqueous solution containing an effective amount of tetrahydrofurfuryl alcohol, tetrahydrofurfuryl amine or mixtures thereof.Type: GrantFiled: July 7, 1988Date of Patent: December 12, 1989Assignee: Great Lakes Chemical CorporationInventors: Charles C. Shin, Nicolai A. Favstritsky, Ahmad Dadgar
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Patent number: 4804484Abstract: Solid sodium bromide and aqueous sodium bromide solutions incorporate sodium tartrate and one or more amides of nitrolotriacetic acid in order to inhibit floc formation in aqueous sodium bromide solutions in the pH range 6-12 and in order to insure that the solid sodium bromide is free flowing.Type: GrantFiled: July 9, 1987Date of Patent: February 14, 1989Assignee: Great Lakes Chemical CorporationInventor: Ahmad Dadgar
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Patent number: 4784779Abstract: The present invention relates to corrosion inhibitors which can be used with calcium-free drilling, completion and workover fluids in carbonate or sulfate containing wells. More particularly, the invention relates to the use of sodium, ammonium and/or calcium thiocyanate alone, or in combination with specific aldose group antioxidants, as corrosion inhibitors. Aldose group antioxidants include arabinose, ascorbic acid, isoascorbic acid, gluconic acid, alkali metal, and alkaline earth or other metal ascorbates, isoascorbates and gluconates and mixtures thereof. Additionally, ammonium thioglycolate may be incorporated as a further corrosion inhibitor.Type: GrantFiled: September 30, 1986Date of Patent: November 15, 1988Assignee: Great Lakes Chemical Corp.Inventor: Ahmad Dadgar
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Patent number: 4762625Abstract: Alkali and alkaline earth metal and zinc halide brines may be viscosified with compositions incorporating a viscosity inducing hydrophilic polymer, mineral oil, oil soluble non-ionic surfactants, polar solvents, and diluent.Type: GrantFiled: September 29, 1986Date of Patent: August 9, 1988Assignee: Great Lakes Chemical Corp.Inventor: Ahmad Dadgar