Patents Assigned to Virginia Polytechnic Institute & State University
  • Patent number: 6255554
    Abstract: A non-human transgenic mammalian animal, as described above, contains an exogenous double stranded DNA sequence stably integrated into the genome of the animal, which comprises cis-acting regulatory units operably linked to a DNA sequence encoding human Factor VIII protein and a signal peptide, where the cis-acting regulatory units are active in mammary gland cells and the signal peptide is active in directing newly expressed Factor VIII into the milk of the animal. The promoter may be a milk protein promoter such as for whey acidic protein, casein, lactalbumin, or beta-lactoglobulin promoter. The transgenic mammals are preferably farm animals, for example, cows, goats, sheep, rabbits and pigs. Concurrent expression of a gene for human von Willebrand's Factor into milk may be used to stabilize newly-secreted Factor VIII.
    Type: Grant
    Filed: March 4, 1999
    Date of Patent: July 3, 2001
    Assignees: American National Red Cross, Virginia Polytechnic Institute & State University
    Inventors: Henryk Lubon, William N. Drohan, William H. Velander
  • Patent number: 6090486
    Abstract: Fiber reinforced thermosetting matrix materials are advantageously created using fibers that are coated with a coating containing a nucleophilic initiator or have a surface treatment which creates a nucleophilic initiator on the surface. The fibers are combined with the thermosetting matrix materials just before curing of the matrix material is desired. These fibers and this methodology avoid premature curing, allow higher levels of initiator to be used to ensure rapid cure, and allow the thermosetting matrix materials to be heated to reduce viscosity.
    Type: Grant
    Filed: April 22, 1999
    Date of Patent: July 18, 2000
    Assignee: Virginia Polytechnic Institute & State University
    Inventors: Judy S. Riffle, Christy S. Tyberg, James E. McGrath
  • Patent number: 5633793
    Abstract: A boost rectifier is provided with an ultra high speed diode in its direct current rail to reduce diode reverse recovery loss with or without implementing a soft switching technique. Full zero-voltage-transition (ZVT) as well as zero-current-transition (ZCT) may also be achieved by adding a simple auxiliary network across the DC rail which operates only during the short turn-on transients of the bridge switches. Similarly, a simple, inexpensive auxiliary circuit can be added to the DC rail of a conventional voltage source inverter shown to implement both ZVT and ZCT.
    Type: Grant
    Filed: January 23, 1995
    Date of Patent: May 27, 1997
    Assignees: Center for Innovative Technology, Virginia Tech Intellectual Properties, Inc., Virginia Polytechnic Institute and State University
    Inventors: Fred C. Lee, Yimin Jiang
  • Patent number: 5625587
    Abstract: A ferroelectric memory device having a perovskite thin film of a rare earth manganate and processes for manufacturing the same. The perovskite thin film layer has properties consistent with high quality nonvolatile memory devices. The perovskite thin film layer can be applied by a MOCVD process, by a MOD process, or a liquid source delivery process, all of which are described.
    Type: Grant
    Filed: July 12, 1995
    Date of Patent: April 29, 1997
    Assignee: Virginia Polytechnic Institute and State University
    Inventors: Chien-Hsiung Peng, Seshu B. Desu, Jie Si
  • Patent number: 5580554
    Abstract: Methods are provided for the diagnosis and treatment of patients with increased risk of gestational hypertension or preeclampsia. The methods involve measuring serum M-CSF levels, and administration of M-CSF.
    Type: Grant
    Filed: March 23, 1995
    Date of Patent: December 3, 1996
    Assignees: Genetics Institute, Inc., Virginia Polytechnic Institute and State University
    Inventor: James C. Keith
  • Patent number: 5574636
    Abstract: An improved zero voltage transition (ZVT) pulse width modulation (PWM) link converter is provided which introduces a space vector modulation scheme and an auxiliary circuit which includes a commutation power supply or special switch arrangement used to discharge resonant inductor currents to zero and to recover commutation energy. In an alternate embodiment, an improved ZVT PWM link converter provides an auxiliary switch for each main switch in the converter to achieve ZVT. The novel ZVT converters provide zero-voltage switching without increasing switching action of the main switches. In this way, the advantages of PWM control is maintained. Conduction loss, turn-off losses, and voltage stress of the main switches are the same as in conventional PWM converters, but the dominant turn-on losses are eliminated, so total power losses are minimized.
    Type: Grant
    Filed: September 9, 1994
    Date of Patent: November 12, 1996
    Assignees: Center for Innovative Technology, Virginia Tech Intellectual Properties, Inc., Virginia Polytechnic Institute and State University
    Inventors: Fred C. Lee, Hengchun Mao
  • Patent number: 5541609
    Abstract: An antenna for a personal communication device designed for reducing RF emissions to a user's head and body comprises a single half-wave dipole antenna element mounted on the top of a telescoping rod such that the antenna element is raised above the user's head when the rod is extended. The rod is completely inactive and serves only to elevate the active antenna element above the user's head and away from the body. A built-in switch is provided which reduces the transmission RF power when the rod is retracted to further protect the user. In a second embodiment, a co-linear array of dipole antenna elements is used. The full array is active for reception. However, a proximity detector senses the proximity of a human body, and lowers the RF transmission power to those antenna elements in the array that are closest to the user's head.
    Type: Grant
    Filed: March 8, 1995
    Date of Patent: July 30, 1996
    Assignees: Virginia Polytechnic Institute and State University, Virginia Tech Intellectual Properties, Inc., Center for Innovative Technology
    Inventors: Warren L. Stutzman, J. Randall Nealy
  • Patent number: 5530111
    Abstract: A method is described for the chemical modification of pre-shaped hydrogels in non-aqueous medium. The conditions permit the reaction of highly expanded, porous hydrogel particles, such as spherical beads, using pseudo homogeneous reaction conditions in the absence of water. The method involves a three step procedure in which the porous gels are solvent exchanged int a water-free solvent (step 1) with minimal change in gel dimension and porosity; followed by reaction under non-aqueous condition (step 2); and followed by solvent exchange into water (step 3). Many different types of reactions requiring non-aqueous conditions may be carried out using these conditions. The method has particularly been demonstrated for crosslinking fluorinating beads, and for esterifying beads in a reaction involving multifunctional free carboxylic acids in the presence of dicyclohexylcarbodiimide (DCC).
    Type: Grant
    Filed: August 29, 1994
    Date of Patent: June 25, 1996
    Assignees: The Center for Innovative Technology, Virginia Polytechnic Institute and State University, Virginia Tech Intellectual Properties, Inc.
    Inventors: Wolfgang G. Glasser, Charles E. Frazier, Gamini Samaranayake
  • Patent number: 5527667
    Abstract: Viral contamination in water samples is detected using a medium which includes both a substrate for .beta.-galactosidase and E. coli with elevated levels of intracellular .beta.-galactosidase. The substrate is chosen to undergo a detectable change (e.g., colorimetric, fluorometric, photometric, etc.) upon cleavage by .beta.-galactosidase. A water sample to be tested for viral contamination is added to the medium. If coliphages are present in the water sample, they will infect, multiply within, and subsequently lyse the E. coli host. Lysis of the E. coli will allow the release of the intracellular .beta.-galactosidase into the media, whereupon the enzyme will cleave the substrate for a detectable reaction. In one particular application, a colorimetric reagent that serves as a substrate for .beta.-galactosidase is dissolved or dispersed within an agar medium, and in another particular application, a colorimetric reagent that serves as a substrate for .beta.
    Type: Grant
    Filed: May 25, 1993
    Date of Patent: June 18, 1996
    Assignees: Virginia Polytechnic Institute and State University, Virginia Tech Intellectual Properties, Inc., The Center for Innovative Technology
    Inventors: M. Marian Ijzerman, Charles Hagedorn, Joseph O. Falkinham
  • Patent number: 5523398
    Abstract: The invention is directed to the formation of cellulose derivatives using homogenous phase reaction conditions. Cellulose is dissolved using DMAc/LiCl and a reagent system is added to promote the acylation of an appropriate acid anhydride or free carboxylic acid. One reagent system includes N,N-dicyclohexylcarbodiimide (DCC) and 4-pyrrolidinopyridine (PP). Another reagent system includes p-toluene sulfonyl chloride (TsCl) and pyridine (Py).
    Type: Grant
    Filed: August 31, 1994
    Date of Patent: June 4, 1996
    Assignees: The Center for Innovative Technology, Virginia Polytechnic Institute and State University, Virginia Tech Intellectual Properties
    Inventors: Wolfgang G. Glasser, Gamini Samaranayake, James E. Sealey, II
  • Patent number: 5515444
    Abstract: An active noise control system using a compact sound source is effective to reduce aircraft engine duct noise. The fan noise from a turbofan engine is controlled using an adaptive filtered-x LMS algorithm. Single multi channel control systems are used to control the fan blade passage frequency (BPF) tone and the BPF tone and the first harmonic of the BPF tone for a plane wave excitation. A multi channel control system is used to control any spinning mode. The multi channel control system to control both fan tones and a high pressure compressor BPF tone simultaneously. In order to make active control of turbofan inlet noise a viable technology, a compact sound source is employed to generate the control field. This control field sound source consists of an array of identical thin, cylindrically curved panels with an inner radius of curvature corresponding to that of the engine inlet.
    Type: Grant
    Filed: October 7, 1994
    Date of Patent: May 7, 1996
    Assignees: Virginia Polytechnic Institute and State University, Virginia Tech Intellectual Properties, The Center for Innovative Technology
    Inventors: Ricardo Burdisso, Chris R. Fuller, Walter F. O'Brien, Russell H. Thomas, Mary E. Dungan
  • Patent number: 5508003
    Abstract: A gallium-indium-zinc-copper metallic material has been found to exhibit many of the advantageous properties of mercury, such as electrical conductivity, fluidity, and high vaporization temperature. The metallic material is formulated by combining individual components in the presence of aqueous base, isolating the metallic phase, and heating the metallic combination. The metallic material is formulated to have sufficient quantities of each of the individual components such that the metallic material has a solidification temperature below 0.degree. C.
    Type: Grant
    Filed: October 11, 1994
    Date of Patent: April 16, 1996
    Assignees: The Center for Innovative Technology, Virginia Tech Intellectual Properties, Virginia Polytechnic Institute and State University
    Inventors: James Rancourt, Larry T. Taylor
  • Patent number: 5493002
    Abstract: Arylethynyl phthalic anhydrides have been synthesized and shown to have particular application as endcappers or pendant groups in high performance/high temperature thermosets which include amine terminal or amine pendant groups.
    Type: Grant
    Filed: July 6, 1994
    Date of Patent: February 20, 1996
    Assignees: Virginia Tech Intellectual Properties, Inc., Virginia Polytechnic Institute and State University
    Inventors: James E. McGrath, Gerald W. Meyer
  • Patent number: 5491102
    Abstract: A ferroelectric device is constructed using a bottom electrode composed of a conducting oxide such as RuO.sub.x, on a substrate such as silicon or silicon dioxide. A ferroelectric material such as lead zirconate titanate (PZT) is deposited on the bottom electrode, and a conducting interlayer is formed at the interface between the ferroelectric and the electrode. This interlayer is created by reaction between the materials of the ferroelectric and electrode, and in this case would be Pb.sub.2 Ru.sub.2 O.sub.7-x. A conductive top layer is deposited over the ferroelectric. This top layer may be a metal, or it may be the same type of materials as the bottom electrode, in which case another interlayer can be formed at the interface. A device constructed in this manner has the property of lower degradation due to fatigue, breakdown, and aging.
    Type: Grant
    Filed: August 10, 1993
    Date of Patent: February 13, 1996
    Assignees: Ceram Incorporated, Sharp Kabushiki Kaisha, Virginia Polytechnic Institute and State University
    Inventors: Seshu B. Desu, In K. Yoo, Chi K. Kwok, Dilip P. Vijay
  • Patent number: 5486752
    Abstract: A zero-current transition pulse-width modulated (ZCT-PWM) d.c.-d.c. converter allows minority-carrier semiconductor devices such as, for example, bipolar junction transistors (BJTs), insulated gate bipolar transistors (IGBTs), MOSFET controlled thyristors (MCTs), and gate turn-off thyristors (GTOs), to be used as switches for high-power, high frequency applications. The ZCT-PWM converter comprises a shunt resonant branch inserted into a conventional PWM converter circuit. The resonant branch comprises a resonant inductor (Lr), a resonant capacitor (Cr), an auxiliary switch (S1), and an auxiliary diode (D1). The resonant branch is only active during a relatively short switching time in order to create a zero-current switch condition for the main pulse-modulating switch (S) without substantially increasing voltage or current stresses.
    Type: Grant
    Filed: June 17, 1994
    Date of Patent: January 23, 1996
    Assignees: Center for Innovative Technology**, Virginia Polytechnic Institute & State University, Intellectual Properties, Inc.
    Inventors: Guichao C. Hua, Fred C. Lee
  • Patent number: 5478610
    Abstract: A method of fabricating high quality layered structure oxide ferroelectric thin films. The deposition process is a chemical vapor deposition process involving chemical reaction between volatile metal organic compounds of various elements comprising the layered structure material to be deposited, with other gases in a reactor, to produce a nonvolatile solid that deposits on a suitably placed substrate such as a conducting, semiconducting, insulating, or complex integrated circuit substrate. The source materials for this process may include organometallic compounds such as alkyls, alkoxides, .beta.-diketonates or metallocenes of each individual element comprising the layered structure material to be deposited and oxygen. Preferably, the reactor in which the deposition is done is either a hot wall or a cold wall reactor and the vapors are introduced into this reactor either through a set of bubblers or through a direct liquid injection system.
    Type: Grant
    Filed: September 2, 1994
    Date of Patent: December 26, 1995
    Assignees: Ceram Incorporated, Sharp Kabushiki, Virginia Polytechnic Institute and State University
    Inventors: Seshu B. Desu, W. Tao
  • Patent number: 5470866
    Abstract: The natural product cephalomannine can be converted to the important anticancer natural product taxol by a simple process involving the steps of dihydroxylation to give cephalomannine-diols, diol cleavage, benzoylation at the 2'-position and reaction with a 1,2-diamine. The same process when applied to mixtures of taxol and cephalomannine makes it possible to separate taxol from cephalomannine-diols by simple flash-chromatography after the dihydroxylation step. If the benzoylation step is avoided in the above sequence of conversions, the process leads to the free amine (N-debenzoyltaxol). In addition, the selection of an acylating reagent other than that with the benzoyl group for acylation of the free amine (N-debenzoyltaxol), allows the preparation of taxol analogs with other N-acyl substituents.
    Type: Grant
    Filed: March 9, 1994
    Date of Patent: November 28, 1995
    Assignee: Virginia Polytechnic Institute and State University
    Inventors: David G. I. Kingston, Anthony A. Molinero, A. A. Leslie Gunatilaka
  • Patent number: 5459475
    Abstract: A novel method for calculating the surface shapes for subreflectors in a suboptic assembly of a tri-reflector spherical antenna system is introduced, modeled from a generalization of Galindo-Israel's method of solving partial differential equations to correct for spherical aberration and provide uniform feed to aperture mapping. In a first embodiment, the suboptic assembly moves as a single unit to achieve scan while the main reflector remains stationary. A feed horn is tilted during scan to maintain the illuminated area on the main spherical reflector fixed throughout the scan thereby eliminating the need to oversize the main spherical reflector. In an alternate embodiment, both the main spherical reflector and the suboptic assembly are fixed. A flat mirror is used to create a virtual image of the suboptic assembly. Scan is achieved by rotating the mirror about the spherical center of the main reflector.
    Type: Grant
    Filed: December 22, 1993
    Date of Patent: October 17, 1995
    Assignees: Center for Innovative Technology, Virginia Polytechnic Institute and State University, Virginia Tech Intellectual Properties, Inc.
    Inventors: Bing Shen, Warren L. Stutzman
  • Patent number: 5458786
    Abstract: Fine coals are dewatered in an energy efficient process in which a non-polar liquid or a mixture of different hydrophobic liquids are used to displace the water from the coal surface. This process works with higher rank coals that are naturally hydrophobic so that the coal surface from which the water is displaced has a stronger affinity for the hydrophobic liquid than the water. Thermodynamically, this process is spontaneous and, hence, requires no energy. The only energy required for this process is to recover the spent hydrophobic liquid(s) for recycling purposes. The hydrophobic liquids are recovered in gaseous form either by lowering the pressure or by heating, and coverted back to liquid form for re-use. The most economical reagents that can be used for this purpose include propane, butane, pentane, and ethane. Carbon dioxide can also be used for the dewatering process described in the present invention.
    Type: Grant
    Filed: April 18, 1994
    Date of Patent: October 17, 1995
    Assignees: The Center for Innovative Technology, Virginia Polytechnic Institute & State University, Virginia Tech Intellectual Properties, Inc.
    Inventors: Roe-Hoan Yoon, Gerald H. Luttrell
  • Patent number: 5446280
    Abstract: A fiber optic sensor is fully compensated for light source intensity variation, fiber losses and modal power distribution by providing input to one end of an optical fiber from a relatively broad band light source containing at least two spectrally separated wavelengths. At least one of these spectrally separated wavelengths is reflected back into the optical fiber by a filter located between a second end of the optical fiber and a reflective transducer. The filter is preferably of the interference edge filter type and has a nominal cut-off wavelength within the spectral band of the light source or between the two spectrally separated wavelengths. Therefore, the paths traversed by light of the spectrally separated wavelengths will differ only by twice traversing the reflective transducer. Temperature measurement or compensation can also be provided by sensing of reflected light intensity or power at approximately the nominal cut-off frequency of the filter.
    Type: Grant
    Filed: August 31, 1993
    Date of Patent: August 29, 1995
    Assignees: Center for Innovative Technology, Virginia Polytechnic Institute and State University, Virginia Tech Intellectual Properties, Inc.
    Inventors: Anbo Wang, Kent A. Murphy, Richard O. Claus