Patents Assigned to Pedro B. Macedo
  • Patent number: 4995984
    Abstract: Compositions comprising carbon-based supports and containing heteropolycyclic compounds such as bipyridyl, phenanthroline or derivatives thereof are used in separation of dissolved late transition metals such as Fe, Co, Ni and Cu from solutions, in particular when such solutions contain high concentrations of other dissolved metals such as Zr, Hf, La, Al and Ba. Such compositions are also used to separate late transition metals such as Pt group metals from each other.
    Type: Grant
    Filed: September 18, 1989
    Date of Patent: February 26, 1991
    Assignees: Pedro B. Macedo, Theodore Aaron Litovitz
    Inventor: Aaron Barkatt
  • Patent number: 4902426
    Abstract: The present invention comprises a process for separating rare earth ions or actinide ions or mixtures thereof in solution by passing the solution through an ion exchange material to separate the rare earths or actinides or mixtures thereof. The ion exchange material has a surface area of about 5-1500 m.sup.2 /g. The ion exchange material is impregnated with a liquid containing alkali metal cations, Group Ib metal cations, ammonium cations, organic amines or mixtures thereof, at a pH range above about 9. A plurality of fractions of the solution is collected as the solution passes through the ion exchange material, preferably in a column. This process is particularly preferred for separating rare earth ions and especially lanthanum and neodymium. It is particularly preferred to purify lanthanum to contain less than 0.1 ppm, preferably less than 0.01 ppm, of neodymium.
    Type: Grant
    Filed: May 20, 1988
    Date of Patent: February 20, 1990
    Assignees: Pedro B. Macedo, Theodore Aaron Litovitz
    Inventors: Pedro B. Macedo, Theodore A. Litovitz, Hamid Hojaj
  • Patent number: 4876232
    Abstract: Compositions comprising carbon-based supports and containing heteropolycyclic compounds such as bipyridyl, phenanthroline or derivatives thereof are used in separation of dissolved late transition metals such as Fe, Co, Ni and Cu from solutions, in particular when such solutions contain high concentrations of other dissolved metals such as Zr, Hf, La, Al and Ba. Such compositions are also used to separate late transition metals such as Pt group metals from each other.
    Type: Grant
    Filed: September 28, 1987
    Date of Patent: October 24, 1989
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventor: Aaron Barkatt
  • Patent number: 4737316
    Abstract: A liquid containing radioactive ions is purified (decontaminated) by contacting the same with an inorganic ion exchange composition having ion exchange sites which can be occupied by the radioactive ions from the liquid. The ion exchange composition is a mixture of an ion exchange medium and an additive which is relatively inert to the ion exchange process and which is a sintering aid for the ion exchange medium designed to lower the sintering temperature of the ion exchange composition. The ion exchange composition may be disposed within a suitable container (e.g., cannister), e.g., made of 304L stainless steel or Inconel 601 and the ion exchange process may be carried out in such container. Alternatively, the ion exchange medium can be employed without being previously admixed with the additive. The additive, if desired, can be admixed at a later stage with the contaminated medium.
    Type: Grant
    Filed: May 20, 1986
    Date of Patent: April 12, 1988
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Pedro B. Macedo, Herbert G. Sutter, Robert K. Mohr, Catherine J. Simmons
  • Patent number: 4687581
    Abstract: A method for separating and purifying cations by ion exchange with regenerable porous glass. More specifically, the method is for decontaminating toxic waste streams such as a radioactive waste streams and concentrating the radioactive cations contained therein which comprises passage of the waste stream through an ion exchange medium of porous silicate glass or silica gel. In one embodiment, a liquid nuclear waste stream is passed through an ion exchange column containing porous silicate glass or silica gel having a plurality of .tbd.Si--O--Z groups wherein Z represents a non-radioactive cation (hydrogen, alkali metals, Group Ib metals and ammonium cations, and mixtures thereof) to displace the non-radioactive cations of the silicate glass or silica gel by the radioactive cations of the waste stream. Thereafter, the ion exchange medium is contacted with an aqueous solution of an acid to strip the radioactive cations therefrom and the stripped ion exchange medium is regenerated.
    Type: Grant
    Filed: January 30, 1984
    Date of Patent: August 18, 1987
    Assignee: Pedro B. Macedo
    Inventors: Pedro B. Macedo, Aaron Barkatt, Herbert G. Sutter
  • Patent number: 4659512
    Abstract: A process for removing metal species from solution comprising passing the liquid over a composition comprising a support such as a porous silicate glass or silica gel or charcoal having interconnected pores and containing water soluble amine complexing agents absorbed on the support capable of forming a stable complex with the metal species. The preferred amine complexing agent is triethylenetetramine. The process is especially useful for removing radioactive cobalt from liquid waste streams.
    Type: Grant
    Filed: December 21, 1983
    Date of Patent: April 21, 1987
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Pedro B. Macedo, Aaron Barkatt
  • Patent number: 4659477
    Abstract: A composition comprising a support such as a porous silicate glass or silica gel or charcoal having interconnected pores and containing heavy metal cations of mercury, thallium, silver, platinum, palladium, lead or copper capable of forming a stable complex with an anion bonded to the support. The preferred heavy metal cation is a mercury cation. The composition is especially useful for removing radioactive iodine from liquid and gaseous waste streams.
    Type: Grant
    Filed: July 28, 1983
    Date of Patent: April 21, 1987
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Pedro B. Macedo, Aaron Barkatt
  • Patent number: 4654146
    Abstract: A process for removing heavy alkali metal cations from solution comprising passing a liquid over a composition including a support such as charcoal having interconnected pores containing a tetra-aryl boron moiety associated with an ion exchangeable cation absorbed on the support capable of forming a stable compound with a heavy alkali metal cation.
    Type: Grant
    Filed: March 25, 1985
    Date of Patent: March 31, 1987
    Assignees: Pedro B. Macedo, Theodore Aaron Litovitz
    Inventors: Aaron Barkatt, Pedro B. Macedo
  • Patent number: 4648975
    Abstract: Silica-based chromatographic and reactive materials are disclosed with surfaces modified to contain or to be coated with oxides, hydrous oxides, hydroxides, carbonates or silicates of aluminum, iron, or other suitable metals such as zirconium or titanium. The materials exhibit good resistance to dissolution and resulting loss of activity or clogging. This good resistance is particularly evident even in the high pH region (above 8-9) and in the high temperature region (above 35.degree. C.) where the dissolution rates and solubilities of aluminosilicates and of trivalent iron oxides are much smaller than those of silica.
    Type: Grant
    Filed: February 27, 1986
    Date of Patent: March 10, 1987
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Aaron Barkatt, Pedro B. Macedo
  • Patent number: 4591455
    Abstract: A liquid containing radioactive ions is purified (decontaminated) by contacting the same with an inorganic ion exchange composition having ion exchange sites which can be occupied by the radioactive ions from the liquid. The ion exchange composition is a mixture of an ion exchange medium and an additive which is relatively inert to the ion exchange process and which is a sintering aid for the ion exchange medium designed to lower the sintering temperature of the ion exchange composition. The ion exchange composition may be disposed within a suitable container (e.g., cannister), e.g., made of 304L stainless steel or Inconel 601 and the ion exchange process may be carried out in such container. Alternatively, the ion exchange medium can be employed without being previously admixed with the additive. The additive, if desired, can be admixed at a later stage with the contaminated medium.
    Type: Grant
    Filed: November 24, 1982
    Date of Patent: May 27, 1986
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Pedro B. Macedo, Herbert G. Sutter, Robert K. Mohr, Catherine J. Simmons
  • Patent number: 4552577
    Abstract: The present invention is directed to a method and apparatus for forming shaped foamed-glass articles. Glass particles are introduced to a pressure vessel in the presence of water. A pressure is applied to the pressure vessel sufficient to permit entrapment of water during sintering and sufficient to prevent foaming at processing temperatures. The temperature of the glass is increased to cause the glass to sinter and entrap water. The temperature of the glass is then increased to its fining temperature (T.sub.F) for a sufficient time to fine the glass. The temperature of the glass is reduced to its pressure release temperature (T.sub.PR). The pressure on the glass containing water is then reduced such as by extrusion to cause controlled foaming of the glass to occur. The glass is then cooled preferably by annealing to form the shaped foamed-glass article, typically pipe insulation.
    Type: Grant
    Filed: April 5, 1983
    Date of Patent: November 12, 1985
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Deepak Varshneya, Pedro B. Macedo, Robert K. Mohr
  • Patent number: 4544499
    Abstract: This invention relates to the immobilization of toxic, e.g., radioactive materials, internally in a silicate glass or silica gel matrix for extremely long periods of time. Toxic materials, such as radioactive wastes containing radioactive anions, and in some cases cations, which may be in the form of liquids, or solids dissolved or dispersed in liquids or gases, are internally incorporated into a glass matrix, having hydrous organofunctionalsiloxy groups, e.g., hydrous aminoalkylsiloxy or carboxyorganosiloxy, bonded to silicon atoms of said glass and/or hydrous polyvalent metals bonded to silicon atoms of said glass through divalent oxygen linkages or otherwise immobilized therein, by a process which involves the ion exchange of said toxic, radioactive anions with hydroxyl groups attached to said organofunctionalsiloxy groups or with hydroxyl groups attached to the hydrous polyvalent metal.
    Type: Grant
    Filed: June 7, 1982
    Date of Patent: October 1, 1985
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Danh C. Tran, Pedro B. Macedo, Joseph H. Simmons, Catherine J. Simmons, Nicholas Lagakos
  • Patent number: 4528011
    Abstract: This invention relates to the immobilization of toxic materials, e.g., radioactive materials, in glass for extremely long periods of time. Toxic materials, such as radioactive wastes, which may be in the form of liquids, or solids dissolved or dispersed in liquids or gases, are deposited in a glass container which is heated to evaporate off non-radioactive volatile materials, if present; to decompose salts, such as nitrates, if any, and to drive off volatile non-radioactive decomposition products, and then to collapse the walls of said container on said radwaste and seal the container and immobilize the contained radwaste, and then burying the resulting product underground or at sea. In another embodiment, the glass container also contains glass particles, e.g., spheres or granules, on which the radwaste solids are deposited.
    Type: Grant
    Filed: December 14, 1981
    Date of Patent: July 9, 1985
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Pedro B. Macedo, Catherine J. Simmons, Danh C. Tran, Nicholas Lagakos, Joseph Simmons
  • Patent number: 4443700
    Abstract: A sensor for measuring stress, temperature, pressure, sound, etc. comprising an optical waveguide, preferably an optical fiber waveguide, a light source which injects light into one end of the waveguide, a deformer contacting and deforming the waveguide to cause light to couple from originally excited modes to other modes, and an optical detector to detect the change in light coupling caused by deformation of the waveguide.
    Type: Grant
    Filed: May 13, 1982
    Date of Patent: April 17, 1984
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Pedro B. Macedo, Theodore A. Litovitz, Nicholas Lagakos, Robert K. Mohr, Robert Meister
  • Patent number: 4362659
    Abstract: This invention relates to radioactive materials which are fixed, stored, entrapped, encapsulated, or otherwise rendered immobile in a glass matrix for extremely long periods of time. Radioactive material such as radioactive wastes are incorporated into a glass matrix by a process of "molecular stuffing" a porous glass either with a radioactive gas which is tapered in the porous glass by dissolution during sintering of the pores of the glass, or with a salt solution containing radioactive material such as CsNO.sub.3, Sr(NO.sub.3), etc., or with a combination of both salt solution and radioactive gas, followed by drying and sintering of the pores of the glass whereby these radioactive materials upon chemical change to their oxides, excepting of course the noble gases which remain in molecular form, become a part of the integrated glass structure.
    Type: Grant
    Filed: September 17, 1979
    Date of Patent: December 7, 1982
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Pedro B. Macedo, Joseph H. Simmons, Theodore A. Litovitz
  • Patent number: 4362542
    Abstract: In a method of making a strong fiber waveguide in which a preform is heated and pulled to make the fiber, the improvement includes adding to the preform at least one dopant capable of creating a mechanical stress profile in the preform and at least another dopant capable of creating an index of refraction profile in the preform, and varying the dopants added to produce a composition profile so that the composition profile varies radially from the center to the surface to form a core, an intermediate clad layer having an index of refraction lower than the core, and a surface layer which is in compression having a thermal expansion coefficient smaller than the core and having a predetermined thickness less than 10% of the radius of the core, the compression being greater than 20,000 psig.
    Type: Grant
    Filed: November 2, 1981
    Date of Patent: December 7, 1982
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Pedro B. Macedo, Robert K . Mohr, Prabhat K. Gupta
  • Patent number: 4342907
    Abstract: A sensor for measuring stress, temperature, pressure, sound, etc. comprising an optical waveguide, preferably an optical fiber waveguide, a light source which injects light into one end of the waveguide, a deformer contacting and deforming the waveguide to cause light to couple from originally excited modes to other modes, and an optical detector to detect the change in light coupling caused by deformation of the waveguide.
    Type: Grant
    Filed: February 1, 1980
    Date of Patent: August 3, 1982
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Pedro B. Macedo, Theodore A. Litovitz, Nicholas Lagakos, Robert K. Mohr, Robert Meister
  • Patent number: 4332031
    Abstract: Silica is selectively removed from aqueous liquid containing a relatively large amount of borate (or boric acid) and a relatively small amount of silica using borate loaded alumina as the sorbant. The effluent can be passed through lithium loaded cation exchange resin to remove any dissolved aluminum.
    Type: Grant
    Filed: March 21, 1980
    Date of Patent: May 25, 1982
    Assignees: Pedro B. Macedo, Theodore A. Litowitz
    Inventors: Aaron Barkatt, Pedro B. Macedo
  • Patent number: 4312774
    Abstract: This invention relates to the immobilization of toxic materials, e.g., radioactive materials, in glass for extremely long periods of time. Toxic materials, such as radioactive wastes, which may be in the form of liquids, or solids dissolved or dispersed in liquids or gases, are deposited in a glass container which is heated to evaporate off non-radioactive volatile materials, if present; to decompose salts, such as nitrates, if any, and to drive off volatile non-radioactive decomposition products, and then to collapse the walls of said container on said radwaste and seal the container and immobilize the contained radwaste, and then burying the resulting product underground or at sea. In another embodiment, the glass container also contains glass particles, e.g., spheres or granules, on which the radwaste solids are deposited.
    Type: Grant
    Filed: April 30, 1979
    Date of Patent: January 26, 1982
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Pedro B. Macedo, Catherine J. Simmons, Danh C. Tran, Nicholas Lagakos, Joseph Simmons
  • Patent number: 4224177
    Abstract: This invention relates to radioactive materials which are fixed, stored, entrapped, encapsulated, or otherwise rendered immobile in a glass matrix for extremely long periods of time. Radioactive material such as radioactive wastes are incorporated into a glass matrix by a process of "molecular stuffing" a porous glass either with a radioactive gas which is trapped in the porous glass by dissolution during sintering of the pores of the glass, or with a salt solution containing radioactive material such as CsNO.sub.3, Sr(NO.sub.3), etc., or with a combination of both salt solution and radioactive gas, followed by drying and sintering of the pores of the glass whereby these radioactive materials upon chemical change to their oxides, excepting of course the noble gases which remain in molecular form, become a part of the integrated glass structure.
    Type: Grant
    Filed: March 9, 1978
    Date of Patent: September 23, 1980
    Assignees: Pedro B. Macedo, Theodore A. Litovitz
    Inventors: Pedro B. Macedo, Joseph H. Simmons, Theodore A. Litovitz