Patents Represented by Attorney Alan A. Thomson
  • Patent number: 6517701
    Abstract: Aqueous solutions containing lead, zinc and manganese are treated to recover these metals by sequential solvent extraction steps. Solvent extractants are selected to extract preferentially lead, then zinc and then manganese in that order. Any interfering metals are removed (as by ion exchange) before extraction. The loaded extractant phases are stripped with selected acids and lead, zinc and manganese each recovered from the strip solutions. Optionally calcium can be recovered when present. A preferred type of extractant (for lead especially) is substituted monothiophosphinic acids. A closed loop system is described which is advantageous with leachate from sulphide and carbonate ores.
    Type: Grant
    Filed: August 14, 2001
    Date of Patent: February 11, 2003
    Assignee: Centaur Mining Exploration Ltd.
    Inventor: Robert A. Geisler
  • Patent number: 5556545
    Abstract: The removal of arsenic, from aqueous liquids by adsorption on alumina, is facilitated by selecting the alumina adsorbent to have a particle size below about 200 micrometers, forming a slurry of the alumina and aqueous liquid and agitating the slurry. It has been found that alumina can be selected to have a particle size sufficiently small, or preferably a combination of both particle size sufficiently small and pore size and number sufficiently large, to achieve 50 ppb or less arsenic within about 2 hours treatment. The alumina with adsorbed arsenic is separated from the slurry by steps preferably comprising microfiltration. A precipitation pretreatment can be combined with the slurry treatment e.g. to handle more concentrated solutions.
    Type: Grant
    Filed: March 3, 1994
    Date of Patent: September 17, 1996
    Assignee: Her Majesty the Queen in right of Canada, as represented by The Secretary of State for the Environment
    Inventors: Konstantin Volchek, Saviz Mortazavi, Harry Whittaker
  • Patent number: 5276110
    Abstract: A carbosilane-based hybrid star polymer having a carbosilane core of large size and addition polymer chains emanating from the core, is described. The carbosilane core is formed from a central silane nucleus and built up by repeated alternating hydrosilylation of reactive vinylic sites followed by vinylation of silicon halide reactive sites. The core is reacted with living addition prepolymers to form the hybrid star polymer. The minimum core size to give the desired properties corresponds to that having at least about 48 reactive silicon halide sites on the periphery. These highly regular hybrid star polymers have unique solution and gelling agent properties and form highly structured and rigid gels, and also act as viscosity modifiers. The large carbosilane core having either vinyl or silicon halide reactive sites can be used as a reactive intermediate.
    Type: Grant
    Filed: August 12, 1992
    Date of Patent: January 4, 1994
    Assignee: National Research Council of Canada
    Inventors: Lin-Lin Zhou, Paul M. Toporowski, Jacques Roovers
  • Patent number: 5105088
    Abstract: Radiation detectors and dosimeters having superheated droplets of detector liquid as the radiation-sensitive component have been found to have significant variation in sensitivity with changes in operating temperature. In order to provide a more constant sensitivity, a self-regulating pressure control has been developed which will alter the pressure on the droplet-containing medium to compensate for changes in operating temperature. The pressure control is for instance a mechanical system selected from a pressure-multiplying piston or bellows assembly pressurized by a volatile liquid, and a spring-loaded elastic diaphragm assembly. This pressure control is designed to maintain a constant degree of superheat of the detector liquid in activated detectors.
    Type: Grant
    Filed: May 7, 1990
    Date of Patent: April 14, 1992
    Assignee: Atomic Energy of Canada Limited
    Inventors: Hugh Boniface, Robert Noulty, John Jevcak, Harry Ing
  • Patent number: 5078212
    Abstract: A method and apparatus for emplacement of dry particulate filter pack and seal material into a borehole to form a monitoring zone for groundwater monitoring which allows the material to be emplaced in dry form. The method involves inserting a tube into the borehole to a depth above a desired monitoring zone and consecutively injecting a first layer of seal material, a layer of filter material and a second layer of seal material, while supplying gas to the tube to prevent groundwater from contacting particulate material while in the tube. The apparatus comprises an injector, including a container and valve assembly adapted for connection to a pressurized gas supply, that allows sequential placement of seal material and filter material while continuously supplying gas to the injection tube.
    Type: Grant
    Filed: September 6, 1990
    Date of Patent: January 7, 1992
    Assignee: Her Majesty the Queen in right of Canada, as represented by the Minister of Energy, Mines and Resources
    Inventors: Daniel R. Boyle, Russell J. Thibedeau, Romeo Forconi
  • Patent number: 5070081
    Abstract: A combined process is described in which inclusion complexes are formed from guest molecules and cyclodextrins during agglomeration of the cyclodextrins. Sufficient agitation in the presence of a small amount of water results in complex formation and bonding into strong agglomerates. The agglomerates are strong and stable and useful inter alia in foods (the guest molecules are flavors), pharmaceuticals (the guest molecules are drugs) and agriculture (the guest molecules are various agrochemicals).
    Type: Grant
    Filed: April 14, 1989
    Date of Patent: December 3, 1991
    Assignee: National Research Council of Canada
    Inventors: Abdul Majid, John A. Ripmeester
  • Patent number: 5035910
    Abstract: Oilseed, particularly whole canola seed, is separated under non-oxidizing conditions, in a non-aqueous solvent system, into high quality oil and proteinaceous flour food components, and a seed coat meal (hull) byproduct. Maceration in a solvent, sequential liquid cyclone separations, and recovery of components and solvent all take place in completely enclosed liquid flow-through systems with solvent recycle, in a relatively short time. This rapid processing avoids oilseed exposure to elevated temperatures and substantially prevents breakdown of certain of its chemical components into antinutritional compounds. Flaking, cooking and pressing stages are not required.
    Type: Grant
    Filed: February 14, 1990
    Date of Patent: July 30, 1991
    Assignee: Her Majesty the Queen in right of Canada, as represented by the Minister of Agricuture
    Inventors: John D. Jones, Douglas S. McGinnis
  • Patent number: 5010005
    Abstract: Whole cells of methylotrophic yeasts are able to oxidize benzyl alcohol to benzaldehyde in aqueous reaction media. However, the low water solubility of the reactant and product of this bioconversion, combined with the ability of both to strongly inhibit the reaction, suggested to us the use of non-aqueous reaction fluids. Using non-aqueous systems, it was found that Pichia pastoris can be used to oxidize higher alcohols. The alcohol oxidase from such yeast had been previously reported unable to oxidize such alcohols. Purified alcohol oxidase was shown to function in a number of two-phase systems of varied aqueous to organic phase concentrations. The stability and biocatalyst recovery of the enzyme was improved by immobilization.
    Type: Grant
    Filed: April 24, 1990
    Date of Patent: April 23, 1991
    Inventors: Sheldon J. B. Duff, William D. Murray
  • Patent number: 5002784
    Abstract: The extraction of natural products from material of biological origin is enhanced and accelerated by concurrent contact with extractant medium and exposure to microwave radiation. Normally the extractant medium is selected to be transparent to the microwave and to remain at ambient temperature: however, if some heating of the medium is permissible it may be partially transparent. Sufficient extractant medium should be present to effect the desired extraction. The extraction products are recovered by standard procedures. Materials used for extraction include mint, sea parsley, cedar foilage and garlic. Extractants may be for instance hexane, dichloromethane or ethanol. Extractions may be in two or more stages with different extractants used in each stage. Some of these extraction products are found to be novel, and quite distinct from steam distillation products.
    Type: Grant
    Filed: May 7, 1990
    Date of Patent: March 26, 1991
    Assignee: Her Majesty the Queen in right of Canada as represented by the Minister of Environment
    Inventors: J. R. Jocelyn Pare, Michel Sigouin, Jacques Lapointe
  • Patent number: 4973783
    Abstract: Various halogenated aromatic compounds, particularly polychlorinated biphls, and the like, are dehalogenated by reaction with alkali metal in the presence of liquid hydrosiloxane. A selected solvent or diluent may be present. The alkali metal halide reaction product may be removed by washing. It has been found substantially complete dehalogenation is achieved readily at ambient temperatures when the hydrosiloxane is present. The dehalogenated aromatic moiety normally is recovered intact. This method has been found very effective in the destruction and removal of PCB contaminants.
    Type: Grant
    Filed: March 16, 1989
    Date of Patent: November 27, 1990
    Assignee: National Research Council Canada/Conseil national de recherches Canada
    Inventors: David Griller, Jalal A. Hawari, Derek J. McPhee
  • Patent number: 4973554
    Abstract: A water soluble ligand bound polymer has been synthesized and used for purification and stabilization of trypsin, an easily autodigestible enzyme. The affinity polymer was formed by copolymerizing N-acryloyl-m-amino-benzamidine, and acrylamide in the absence of oxygen. Bound trypsin could be easily eluted by either arginine or benzamidine. At low temperature (< C.), the polymer solution was very stable and retained its high capacity for trypsin binding after 6 months of storage. Trypsin can also be stored in this system for extended periods. Combining the principles of affinity chromatography and ultrafiltration, a process has been developed, using this polymer, for purification of trypsin. The purification process also features provisions for the recirculation of the eluant as well as the macroligand.
    Type: Grant
    Filed: February 26, 1988
    Date of Patent: November 27, 1990
    Assignee: National Research Council of Canada
    Inventors: John H. Luong, Keith B. Male, An-Lac Nguyen
  • Patent number: 4929553
    Abstract: This invention is concerned with the specific processing of secreted proteins in genetically modified yeast cells. The yeast KEX1 gene was cloned and the KEX1 product was shown to be a serine protease, evidently a carboxypeptidase B-like protease. A probable site of processing of polypeptides by the KEX1 gene product is at the C-terminus of the .alpha. subunit of the killer toxin, where the mature toxin subunit is followed in the precursor by a pair of basic amino acid residues. Processing likely involves an endoprotease cut following these basic residues, and their subsequent C-terminal trimming by a carboxypeptidase. Consistent with the KEX1 product being this carboxypeptidase is the finding that it is also involved in .alpha.-factor pheromone production. In wildtype yeast, KEX1 is not essential for .alpha.-factor production, as the final hormone repeat in the prepro .alpha.-hormone precursor does not need C-terminal processing to form one copy of the active hormone. However, in a mutant strain where .
    Type: Grant
    Filed: May 29, 1987
    Date of Patent: May 29, 1990
    Assignee: Canadian Patents & Development Ltd.
    Inventors: Howard Bussey, Aleksandra Dmochowska, David Y. Thomas, Daniel Dignard
  • Patent number: 4913730
    Abstract: Gold is recovered from aqueous solutions which include a solubilizing reagent by contacting the solution with hydrogen under selected conditions until the gold precipitates, and removing the precipitate from the solution. The reagent comprises a thiourea or a thiosulfate and the solution is a leach, eluate or strip solution. The contacting may be by gas sparging or under hydrogen pressures, e.g. up to about 300 psi, and usually the temperature is within about to C. If the initial feed solution is too dilute, it can be concentrated by ion exchange or solvent extraction followed by elution or stripping respectively. Any silver present is precipitated with the gold.
    Type: Grant
    Filed: May 4, 1988
    Date of Patent: April 3, 1990
    Assignee: Canadian Patents and Development Ltd.
    Inventors: Guy Deschenes, Gordon M. Ritcey
  • Patent number: 4902507
    Abstract: An insecticidal composition for controlling or inhibiting the growth of larvae of the Bertha armyworm, comprising an insecticidal substance of one or more strains of Bacillus thuringiensis and an insecticidally acceptable carrier. The strains belong to the varieties aizawai, kurstaki and kenyae and include Bacillus thuringiensis var. aizawai strain HD-133.
    Type: Grant
    Filed: August 14, 1987
    Date of Patent: February 20, 1990
    Assignee: Canadian Patents & Development Ltd.
    Inventors: Oswald N. Morris, Marc R. Trottier
  • Patent number: 4902344
    Abstract: The present invention relates to an aqueous ferric chloride leach process for the extraction of metal values from a metal-sulphide bearing material, the leach being carried out in the presence of a leaching aid chosen from among salts of diesters of sulphodicarboxylic acids. It, in particular, relates to the enhanced recovery of metal values from complex, metal-sulphide bearing materials such as, for example, fine grained, polymetallic sulphide ores, their concentrates or the like.
    Type: Grant
    Filed: October 27, 1988
    Date of Patent: February 20, 1990
    Assignee: Canadian Patents & Development Ltd.
    Inventors: Bernard H. Lucas, David Y. Shimano
  • Patent number: 4888108
    Abstract: Dispersed solids, particularly fine peptized hydrophobic solids, present in some petroleum oils, bitumen solutions or concentrates, heavy oils and the like, may be removed by distributing an additive selected from resorcinol, catechol, formic acid, maleic acid or anhydride, chloral hydrate and asphaltene - precipitating solvents (preferably certain mixtures thereof) throughout the dispersion to cause small agglomerates containing the solids to form, and separating the agglomerates from the residual liquid. This residual liquid is rendered more suitable for various refining processes. Agglomerates containing asphaltenes and mineral solids may be used e.g. in hydrogen generation, for compounding roofing materials and in paving materials.
    Type: Grant
    Filed: June 23, 1988
    Date of Patent: December 19, 1989
    Assignee: Canadian Patents and Development Limited
    Inventor: J. Redmond Farnand
  • Patent number: 4871669
    Abstract: Methylotrophic yeasts of the genera Pichia, Torulopsis, Candida and Hansenula when grown on methanol, make use of an enzyme, alcohol oxidase, to catalyse the initial oxidation of methanol to formaldehyde. Non-growing whole cells of such methylotrophic yeasts were used in place of purified alcohol oxidase for the production of flavoring aldehydes from their respective alcohols. To reduce end product inhibition a number of amine buffers, which chelate the aldehydes, were studied and an increase in aldehyde production was demonstrated with selected buffers which maintain a weakly alkaline pH.
    Type: Grant
    Filed: June 27, 1988
    Date of Patent: October 3, 1989
    Assignee: Canadian Patents & Development Limited
    Inventors: William D. Murray, Sheldon J. B. Duff, Patricia H. Lanthier
  • Patent number: 4870014
    Abstract: This inverntion concerns a glycoamylase gene cloned into the yeast Saccharomyces cerevisiae, method for cloning such a gene into such yeasts and cloning vehicles containing such a gene, suitable for use in Saccharomyces cerevisiae. Yeast containing a glucoamylase gene are of potential use in the brewing industry.
    Type: Grant
    Filed: September 16, 1985
    Date of Patent: September 26, 1989
    Assignee: Canadian Patents and Development Ltd.
    Inventors: Judy A. Eratt, Anwar Nasim
  • Patent number: 4851484
    Abstract: An anhydride-cured epoxy resin (epoxy resin+anhydride curing agent+catalyst) may be fortified (i.e. increased in strength and modulus without being made brittle) by the addition of a carboxylic acid and the reaction product of a carboxylic acid anhydride and a substituted aromatic amine. Strengths as high as 125 MPa and moduli as high as 3500 MPa have been attained, as well as elongations up to 6% and an increase in the ability of the plastic to yield before fracture (ductility), compared to 80 MPa strength, 3000 MPa modulus and 2.4% elongation for the unfortified system (strengths and moduli are tensile).
    Type: Grant
    Filed: March 3, 1988
    Date of Patent: July 25, 1989
    Assignee: Canadian Patents & Development Ltd.
    Inventors: Andrew Garton, Paul D. McLean
  • Patent number: 4837146
    Abstract: Sclerotinia stem rot, caused by the fungus Sclerotinia sclerotiorum (L ib.) de Bary, is a major disease of rapeseed (canola) in western Canada and many other parts of the world. Significant yield losses result from severe crop infestatons. A method of stem rot disease forecasting is disclosed. The method is based on the relationship discovered between infestation of top plant parts with spores of the fungus at early bloom and subsequent disease incidence. Also disclosed are media compositions, which facilitate rapid growth of S. sclerotiorum from plant parts under non-sterile conditions and thereby permit detection of the fungus. This forecasting system allows improved disease risk assessement in advance of the need for spraying against sclerotinia stem rot.
    Type: Grant
    Filed: May 18, 1987
    Date of Patent: June 6, 1989
    Assignee: Canadian Patents & Development Ltd.
    Inventors: Robin A. A. Morrall, T. K. Turkington, Richard K. Gugel, Sheldon V. Rude