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Oriented biopolymeric membrane
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PATENTS
dehydration of natural gas. Patent number: WO 02/38250 Inventor: J.H. Hallman Publication date: 16 May 2002
corrosive properties of the brine. Patent number: WO 02/40747 Publication date: 23 May 2002
Improved haemodialysis apparatus
Preparation of thromboplastin reagents
Applicant/Inventor: A. Belson, USA An apparatus for improved haemodialysis treatment has been developed. It includes a module with an ultrasonic transducer coupled to a membrane or hollow fibre dialyzer. An ultrasonic waveform generator is switchable between various modes, including a narrowband sine wave, a variable or sweeping frequency sine wave and a broadband square or sawtooth waveform. A low power setting is used to increase the diffusion rate across the semi-permeable membranes of the dialyzer, and a high power setting is used intermittently to break up a thrombus that may form within the dialyzer. A chamber downstream of the dialyzer has an ultrasonic or optical emboli sensor for detecting thrombi or emboli exiting the dialyzer, and a focused ultrasonic transducer to break up any emboli in the chamber. A screen or filter at the exit of the chamber prevents thrombi and emboli larger than a certain size from entering the patient’s circulatory system. Patent number: WO 02/38201 Publication date: 16 May 2002
Assignee: Sigma-Aldrich Co, USA Disclosed are mammalian thromboplastin reagents and methods for preparing such reagents. These reagents are suitable for use in prothrombin-time (PT) assays, and offer improved sensitivities with acceptable PT-normal times. Contaminating proteins – particularly plasma clotting factors – are separated from a thromboplastin solution by a membrane permeation protocol, in which the thromboplastin solution is exposed to a semi-permeable membrane, and clotting factors are allowed to pass from the thromboplastin solution through the membrane, while tissue factor is retained in the thromboplastin solution. In a preferred method, one or more contaminating clotting factors are separated by diafiltration from a NaCl/Na3 citrate thromboplastin extract of mammalian tissue, and the purified thromboplastin extract is combined with Ca++ ions to form a thromboplastin reagent. Patent number: US 6 391 609 Inventor: M.D. Goldford Publication date: 21 May 2002
Membrane-based cathodic protection system
Fluid barrier membranes
Applicant/Inventor: G.I. Russell, USA A cathodic protection system for corrosion protection of metallic structures in contact with aqueous solutions such as salt water and calcium chloride brine is covered by this patent. The system employs anode chambers, containing hydroxide anolytes segregated from an electrolyte containing chloride by an ion-exchange membrane. The anode and the structures to be protected are coupled to voltage and current sources impressing a current at the immersed surfaces of the metallic structures in order to maintain these surfaces close to an equipotential, and are covered with a bound layer of polarized hydroxide. The preferred embodiment is used in connection with stainless steel holding tanks and associated equipment. When the brine and the anolyte contact the membrane, a bi-ionic potential forms across the membrane that drives the counterdirected transport of ions through the membrane, thereby preventing the anodic production of 12C. Additionally, pH control is employed and a controller is coupled to one or more of a series of reference electrodes used to monitor the potential differences between the electrodes and the metal surfaces to be cathodically protected. If the potential difference falls outside of a predetermined range, because of changing exposure conditions and/or operating parameters, the applied voltage is adjusted so that the current from the anode produces a polarized and alkaline protective film at the metallic surfaces of the holding tank and associated equipment so as to counteract and overcome the
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Assignee: Nike Inc, USA This invention details a membrane that includes as a gas-barrier component comprising a polyester polyol-modified polyurethane. The polyester polyol portion has repeating units in which the total number of carbon atoms is about eight or less. The membrane has a transmission rate of 15.0 or less for nitrogen gas. Patent number: US 6 391 405 Inventors: H.W. Bonk, D.J. Goldwasser, P.H. Mitchell Publication date: 21 May 2002
carrying out a chemical conversion and subsequent cleaning with water. The cleaning process is performed in one or more stages and comprises a step of withdrawing aqueous wash from a first cleaning stage and adjusting the pH of this wash with at least one acid selected from a group that includes phosphoric acid, nitric acid, hydrofluoric acid, hydrosilicofluoric acid and fluoroboric acid. It also involves treating the pHadjusted aqueous wash with a first reverse osmosis (RO) membrane to separate it into a first filtrate and a first concentrate, and a step of neutralizing the first filtrate with an alkali, and treating the alkali-neutralized filtrate with a second RO membrane to separate it into a second filtrate and a second concentrate. The first concentrate is recycled for phosphate chemical conversion, and the second filtrate is recycled as aqueous wash for aqueous cleaning. The second concentrate is discarded from the system. Patent number: US 6 391 206 Inventors: H. Chihara, S. Shirahata, S. Shiraishi, N. Tada, T. Kawashima, H. Morita, Y. Ohashi Publication date: 21 May 2002
Ion exchange membrane Assignee: RhoCraft Research and Development Ltd, USA An ion exchange membrane for use in sensors which measure dissolved gases is the subject of this patent. Disclosed is a method for using ion exchangers in gas permeable membranes to maintain optimal conditions in the electrolyte contained within the sensor. This can greatly extend the service lifetime and improve the stability of sensors of similar size and electrolyte volume that have been constructed using prior art. Patent number: US 6 391 174 Inventors: R.D. Rowe, T.M. Fyles, G.D. Robertson Publication date: 21 May 2002
Extracting and analyzing gases Oriented biopolymeric membrane Assignee: Collagen Matrix Inc, USA This patent describes a sheet membrane containing a layer of oriented biopolymeric fibres. The membrane has a thickness of 0.1–3.0 mm, a density of 0.1–1.2 g/cm3, a hydrothermal shrinkage temperature of 50°C–85°C, a suture pullout strength of 0.1–5 kg, a tensile strength of 10–150 kg/cm3, and permeability to molecules having molecular weights of 200 to 300 000 daltons. Patent number: US 6 391 333 Inventors: S.-T. Li, D. Yuen Publication date: 21 May 2002
Recovery of aqueous wash in phosphate chemical conversion Assignee: Nippon Paint Co Ltd, Japan This invention is related to a method for recovering aqueous wash in a phosphate chemical conversion of a shaped metal product. It involves
Assignee: Serveron Corp, USA A tubular membrane extractor column is connected to an oil-filled electrical component such as a transformer. Fault gases dissolved in the transformer oil are extracted from the oil in the separator and are isolated in a second phase. Oil and second phase gas are circulated in separate flow paths until equilibrium is reached. Equilibrated gas is routed to a gas chromatograph or other analytical instrument requiring controlled fluid flow, and which incorporates a manifold assembly that eliminates the need for many of the external fittings and connections required in the instrument. A manifold block contains a number of fluid flow paths to route fluids to selected components. A collar mates to the block and adapts to a rotary injection valve to provide the continued fluid paths from the block to the injector valve and the other components of the instrument. Patent number: US 6 391 096
Membrane Technology August 2002
8/14/02
12:42 PM
Page 12
PATENTS
dehydration of natural gas. Patent number: WO 02/38250 Inventor: J.H. Hallman Publication date: 16 May 2002
corrosive properties of the brine. Patent number: WO 02/40747 Publication date: 23 May 2002
Improved haemodialysis apparatus
Preparation of thromboplastin reagents
Applicant/Inventor: A. Belson, USA An apparatus for improved haemodialysis treatment has been developed. It includes a module with an ultrasonic transducer coupled to a membrane or hollow fibre dialyzer. An ultrasonic waveform generator is switchable between various modes, including a narrowband sine wave, a variable or sweeping frequency sine wave and a broadband square or sawtooth waveform. A low power setting is used to increase the diffusion rate across the semi-permeable membranes of the dialyzer, and a high power setting is used intermittently to break up a thrombus that may form within the dialyzer. A chamber downstream of the dialyzer has an ultrasonic or optical emboli sensor for detecting thrombi or emboli exiting the dialyzer, and a focused ultrasonic transducer to break up any emboli in the chamber. A screen or filter at the exit of the chamber prevents thrombi and emboli larger than a certain size from entering the patient’s circulatory system. Patent number: WO 02/38201 Publication date: 16 May 2002
Assignee: Sigma-Aldrich Co, USA Disclosed are mammalian thromboplastin reagents and methods for preparing such reagents. These reagents are suitable for use in prothrombin-time (PT) assays, and offer improved sensitivities with acceptable PT-normal times. Contaminating proteins – particularly plasma clotting factors – are separated from a thromboplastin solution by a membrane permeation protocol, in which the thromboplastin solution is exposed to a semi-permeable membrane, and clotting factors are allowed to pass from the thromboplastin solution through the membrane, while tissue factor is retained in the thromboplastin solution. In a preferred method, one or more contaminating clotting factors are separated by diafiltration from a NaCl/Na3 citrate thromboplastin extract of mammalian tissue, and the purified thromboplastin extract is combined with Ca++ ions to form a thromboplastin reagent. Patent number: US 6 391 609 Inventor: M.D. Goldford Publication date: 21 May 2002
Membrane-based cathodic protection system
Fluid barrier membranes
Applicant/Inventor: G.I. Russell, USA A cathodic protection system for corrosion protection of metallic structures in contact with aqueous solutions such as salt water and calcium chloride brine is covered by this patent. The system employs anode chambers, containing hydroxide anolytes segregated from an electrolyte containing chloride by an ion-exchange membrane. The anode and the structures to be protected are coupled to voltage and current sources impressing a current at the immersed surfaces of the metallic structures in order to maintain these surfaces close to an equipotential, and are covered with a bound layer of polarized hydroxide. The preferred embodiment is used in connection with stainless steel holding tanks and associated equipment. When the brine and the anolyte contact the membrane, a bi-ionic potential forms across the membrane that drives the counterdirected transport of ions through the membrane, thereby preventing the anodic production of 12C. Additionally, pH control is employed and a controller is coupled to one or more of a series of reference electrodes used to monitor the potential differences between the electrodes and the metal surfaces to be cathodically protected. If the potential difference falls outside of a predetermined range, because of changing exposure conditions and/or operating parameters, the applied voltage is adjusted so that the current from the anode produces a polarized and alkaline protective film at the metallic surfaces of the holding tank and associated equipment so as to counteract and overcome the
12
Assignee: Nike Inc, USA This invention details a membrane that includes as a gas-barrier component comprising a polyester polyol-modified polyurethane. The polyester polyol portion has repeating units in which the total number of carbon atoms is about eight or less. The membrane has a transmission rate of 15.0 or less for nitrogen gas. Patent number: US 6 391 405 Inventors: H.W. Bonk, D.J. Goldwasser, P.H. Mitchell Publication date: 21 May 2002
carrying out a chemical conversion and subsequent cleaning with water. The cleaning process is performed in one or more stages and comprises a step of withdrawing aqueous wash from a first cleaning stage and adjusting the pH of this wash with at least one acid selected from a group that includes phosphoric acid, nitric acid, hydrofluoric acid, hydrosilicofluoric acid and fluoroboric acid. It also involves treating the pHadjusted aqueous wash with a first reverse osmosis (RO) membrane to separate it into a first filtrate and a first concentrate, and a step of neutralizing the first filtrate with an alkali, and treating the alkali-neutralized filtrate with a second RO membrane to separate it into a second filtrate and a second concentrate. The first concentrate is recycled for phosphate chemical conversion, and the second filtrate is recycled as aqueous wash for aqueous cleaning. The second concentrate is discarded from the system. Patent number: US 6 391 206 Inventors: H. Chihara, S. Shirahata, S. Shiraishi, N. Tada, T. Kawashima, H. Morita, Y. Ohashi Publication date: 21 May 2002
Ion exchange membrane Assignee: RhoCraft Research and Development Ltd, USA An ion exchange membrane for use in sensors which measure dissolved gases is the subject of this patent. Disclosed is a method for using ion exchangers in gas permeable membranes to maintain optimal conditions in the electrolyte contained within the sensor. This can greatly extend the service lifetime and improve the stability of sensors of similar size and electrolyte volume that have been constructed using prior art. Patent number: US 6 391 174 Inventors: R.D. Rowe, T.M. Fyles, G.D. Robertson Publication date: 21 May 2002
Extracting and analyzing gases Oriented biopolymeric membrane Assignee: Collagen Matrix Inc, USA This patent describes a sheet membrane containing a layer of oriented biopolymeric fibres. The membrane has a thickness of 0.1–3.0 mm, a density of 0.1–1.2 g/cm3, a hydrothermal shrinkage temperature of 50°C–85°C, a suture pullout strength of 0.1–5 kg, a tensile strength of 10–150 kg/cm3, and permeability to molecules having molecular weights of 200 to 300 000 daltons. Patent number: US 6 391 333 Inventors: S.-T. Li, D. Yuen Publication date: 21 May 2002
Recovery of aqueous wash in phosphate chemical conversion Assignee: Nippon Paint Co Ltd, Japan This invention is related to a method for recovering aqueous wash in a phosphate chemical conversion of a shaped metal product. It involves
Assignee: Serveron Corp, USA A tubular membrane extractor column is connected to an oil-filled electrical component such as a transformer. Fault gases dissolved in the transformer oil are extracted from the oil in the separator and are isolated in a second phase. Oil and second phase gas are circulated in separate flow paths until equilibrium is reached. Equilibrated gas is routed to a gas chromatograph or other analytical instrument requiring controlled fluid flow, and which incorporates a manifold assembly that eliminates the need for many of the external fittings and connections required in the instrument. A manifold block contains a number of fluid flow paths to route fluids to selected components. A collar mates to the block and adapts to a rotary injection valve to provide the continued fluid paths from the block to the injector valve and the other components of the instrument. Patent number: US 6 391 096
Membrane Technology August 2002