Patents Assigned to Virginia Tech
  • Patent number: 8811039
    Abstract: A power converter including a resonant circuit is controlled by pulse width modulation (PWM) of a switching circuit to control current in the resonant circuit near the frequency of the resonant circuit (a null-immittance criterion) in order to control current and voltage at the output of the resonant circuit. Further control of voltage can be performed by PWM of a switching circuit at the output of the resonant circuit such that centers of the duty cycles of respective switches for the output of the resonant circuit are substantially synchronized and substantially symmetrical about centers of said duty cycles of respective switches at the input of the resonant circuit. Thus, operation of the converter is substantially simplified by using only PWM, a wide range of input and output voltages can be achieved and the converter circuit can be configured for bi-directional power transfer.
    Type: Grant
    Filed: July 18, 2011
    Date of Patent: August 19, 2014
    Assignee: Virginia Tech Intellectual Properties, Inc.
    Inventors: Khai Doan The Ngo, Xiao Cao, Yin Wang
  • Patent number: 8811700
    Abstract: A system and method for tomographic image reconstruction using truncated projection data that allows exact interior reconstruction (interior tomography) of a region of interest (ROI) based on the known sparsity models of the ROI, thereby improving image quality while reducing radiation dosage. In addition, the method includes parallel interior tomography using multiple sources beamed at multiple angles through an ROI and that enables higher temporal resolution.
    Type: Grant
    Filed: April 15, 2010
    Date of Patent: August 19, 2014
    Assignee: Virginia Tech Intellectual Properties, Inc.
    Inventors: Ge Wang, Hengyong Yu
  • Patent number: 8803489
    Abstract: Light load efficiency of a power factor correction circuit is improved by adaptive on-time control and providing for selection between a continuous conduction mode and a discontinuous conduction mode wherein the discontinuous conduction mode increases time between switching pulses controlling connection of a cyclically varying voltage to a filter/inductor that delivers a desired DC voltage and thus can greatly reduce the switching frequency at light loads where switching frequency related losses dominate efficiency. The mode for controlling switching is preferably selected for each switching pulse within a half cycle of the cyclically varying input voltage. A multi-phase embodiment allows cancellation of EMI noise at harmonics of the switching frequency and adaptive change of phase angle allows for cancellation of dominant higher order harmonics as switching frequency is reduced.
    Type: Grant
    Filed: July 18, 2011
    Date of Patent: August 12, 2014
    Assignee: Virginia Tech Intellectual Properties, Inc.
    Inventors: Qian Li, Fred C. Lee, Ming Xu, Chuanyun Wang
  • Publication number: 20140220067
    Abstract: The present invention provides a novel chimeric porcine circovirus infectious DNA clone and live attenuated chimeric virus with the PCV2, preferably of subtype PCV2b, capsid gene integrated into a non-pathogenic PCV1 virus genome. In a particular embodiment, the PCV2 capids gene is of subtype PCV2b, the predominant subtype circulating in pigs worldwide. The attenuated chimeric virus, designated PCV1-2b, effectively protects pigs from PCV2b challenges, and can be used as a live vaccine, as well as an inactivated (killed) vaccine, that provides protection and cross protection against PCV2b and PCV2a subtypes infection. The live attenuated vaccine of the present invention is also effective protecting pigs from porcine circovirus-associated disease (PCVAD).
    Type: Application
    Filed: February 6, 2014
    Publication date: August 7, 2014
    Applicant: Virginia Tech Intellectual Properties, Inc.
    Inventors: Xiang-Jin MENG, Nathan M. Beach, Sheela Ramamoorthy
  • Patent number: 8798722
    Abstract: The present invention relates to the field of optical imaging and therapeutics. More particularly, embodiments of the present invention provide minimally-invasive Fiberoptic Microneedle Devices (FMDs) for light-based therapeutics, which physically penetrate tissue and deliver light directly into the target area below the skin surface (FIG. 1). A preferred embodiment of the invention is a fiberoptic microneedle device comprising: (a) one or more silica-based needles capable of guiding light and comprising a length of about 0.5-6 mm, a base having an outer diameter in the range of about 100-150 micron, and a tip having an outer diameter in the range of about 5-20 micron; (b) a support member to which the needles are secured; (c) a ferrule comprising one or more holes for each of the needles, wherein the ferrule is operably configured to provide mechanical support to each needle at all or some portion of the length of the needle.
    Type: Grant
    Filed: March 1, 2010
    Date of Patent: August 5, 2014
    Assignee: Virginia Tech Intellectual Properties, Inc.
    Inventors: Christopher Rylander, Thomas A. Campbell, Ge Wang, Yong Xu, Mehmet Alpaslan Kosoglu
  • Publication number: 20140210282
    Abstract: Wobbling the operating frequency of a phase-locked loop (PLL), preferably by adding a periodic variation is feedback gain or delay in reference signal phase allows the avoidance of any non-detection zone that might occur due to exact synchronization of the phase locked loop operating frequency with a reference signal. If the change in PLL operating frequency is periodic, it can be made of adequate speed variation to accommodate and time requirement for islanding detection or the like when a reference signal being tracked by the PLL is lost. Such wobbling of the PLL operating frequency is preferably achieved by addition a periodic variable gain in a feedback loop and/or adding a periodically varying phase delay in a reference signal and/or PLL output.
    Type: Application
    Filed: August 16, 2013
    Publication date: July 31, 2014
    Applicant: Virginia Tech Intellectual Properties, Inc.
    Inventors: Dong Dong, Dushan Boroyevich, Paolo Mattavelli
  • Publication number: 20140212283
    Abstract: A tilting pad bearing for a high speed rotary machines, such as a turbocharger for an internal combustion engine, comprises a cage and a plurality of tilting pads. The cage is formed by two annular rings separated by spacers machined from a single billet of high-temperature metal. The bearing pads are inserted between the spacers of the cage. One or more O-rings retain the bearing pads within the cage during assembly of the bearing but are not required after installation of the bearing. When retained in the final assembly and installation of the bearing, the O-rings allow tilting movement of the pads within the cage. The outer surfaces of the spacers have a plurality of grooves, and outer surfaces of each of the pads have matching grooves. One of the grooves is an oil groove, wherein the oil groove of the spacers communicating with and oil inlet holes in the spacers. At least one of the other grooves receives an O-ring that hold the pads in place in the cage during installation.
    Type: Application
    Filed: August 27, 2012
    Publication date: July 31, 2014
    Applicant: VIRGINIA TECH INTELLECTUAL PROPERTIES, INC.
    Inventors: R. Gordon Kirk, Willliam Songer
  • Patent number: 8785376
    Abstract: In one aspect, the invention relates to isolated compounds useful as antifungal agents, for example, compounds having a structure represented by a formula: wherein R1 is hydrogen or hydroxyl; wherein R2 is hydrogen or xylose; and wherein R3 and R4 are each hydrogen or together oxygen, or a pharmaceutically acceptable salt thereof; methods of isolating and purifying same; pharmaceutical compositions comprising same; agricultural compositions comprising same; and methods of treating and/or preventing fungal infections using same. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present invention.
    Type: Grant
    Filed: December 20, 2011
    Date of Patent: July 22, 2014
    Assignees: Virginia Tech Intellectual Properties, University of Utah Research Foundation
    Inventors: Eric W. Schmidt, Joseph O. Falkinham, Peter W. Jeffs
  • Patent number: 8784566
    Abstract: Embodiments of the present invention overcome the well-known recalcitrance of lignocellulosic biomass in an economically viable manner. A process and system are provided for the efficient fractionation of lignocellulosic biomass into cellulose, hemicellulose sugars, lignin, and acetic acid. The cellulose thus obtained is highly amorphous and can be readily converted into glucose using known methods. Fermentable hemicellulose sugars, low-molecular-weight lignin, and purified acetic acid are also major products of the process and system. The modest process conditions and low solvent/solid ratios of some embodiments of the invention imply relatively low capital and processing costs.
    Type: Grant
    Filed: March 29, 2006
    Date of Patent: July 22, 2014
    Assignee: Virginia Tech Intellectual Properties, Inc.
    Inventor: Y. H. Percival Zhang
  • Publication number: 20140190471
    Abstract: Embodiments of the present invention overcome the well-known recalcitrance of lignocellulosic biomass in an economically viable manner. A process and system are provided for the efficient fractionation of lignocellulosic biomass into cellulose, hemicellulose sugars, lignin, and acetic acid. The cellulose thus obtained is highly amorphous and can be readily converted into glucose using known methods. Fermentable hemicellulose sugars, low-molecular-weight lignin, and purified acetic acid are also major products of the process and system. The modest process conditions and low solvent/solid ratios of some embodiments of the invention imply relatively low capital and processing costs.
    Type: Application
    Filed: March 19, 2014
    Publication date: July 10, 2014
    Applicant: Virginia Tech Intellectual Properties, Inc.
    Inventor: Y. H. Percival Zhang
  • Publication number: 20140187681
    Abstract: Components of an unmanned undersea vehicle are inspired by jellyfish that uses its flexible body and tilt sensing to achieve efficient swimming and turning. A tilt sensor, based on a statocyst, has a metal ball in a chamber lined with resistors. The tilt is sensed in accordance with which resistors the ball contacts. A composition of polyvinyl alcohol hydrogel with ferritin particles dispersed therein mimics the qualities of a jellyfish's mesoglea.
    Type: Application
    Filed: December 31, 2012
    Publication date: July 3, 2014
    Applicant: Virginia Tech Intellectual Properties, Inc.
    Inventors: Colin SMITH, Shashank Priya
  • Patent number: 8700257
    Abstract: A method and device for use in pedestrian-vehicular collisions in which an active hood lift system is deployed to a first elevated lift position and maintained at the deployed position for an interval after which it is lowered, thereby controlling pedestrian impact kinetics and reducing forces that can result pedestrian injuries.
    Type: Grant
    Filed: May 13, 2010
    Date of Patent: April 15, 2014
    Assignees: Toyota Motor Engineering & Manufacturing North America, Inc., Virginia Tech Intellectual Properties, Inc.
    Inventors: Atsutaka Tamura, Stefan Duma
  • Patent number: 8698579
    Abstract: Common mode (CM) and differential mode (DM) components of multi-phase conducted electromagnetic interference (EMI) noise emanating from electronic circuits such as power converters/inverters are separated by respective coupled inductors connected to each phase of three or more phases and which are coupled to each other differently for CM and DM noise of the respective phases. The inductors of the DM separation unit are coupled such that a substantially ideal zero impedance is presented to DM noise while a high impedance is presented to CM noise. Conversely, the inductors of the CM separation unit are coupled such that a substantially ideal zero impedance is presented to CM noise while a high impedance is presented to DM noise.
    Type: Grant
    Filed: March 25, 2011
    Date of Patent: April 15, 2014
    Assignee: Virginia Tech Intellectual Properties, Inc.
    Inventors: Shuo Wang, Fred C. Lee
  • Patent number: 8691974
    Abstract: A novel BC fermentation technique for controlling 3D shape, thickness and architecture of the entangled cellulose nano-fibril network is presented. The resultant nano-cellulose based structures are useful as biomedical implants and devices, are useful for tissue engineering and regenerative medicine, and for health care products. More particularly, embodiments of the present invention relate to systems and methods for the production and control of 3-D architecture and morphology of nano-cellulose biomaterials produced by bacteria using any biofabrication process, including the novel 3-D Bioprinting processes disclosed. Representative processes according to the invention involve control of the rate of production of biomaterial by bacteria achieved by meticulous control of the addition of fermentation media using a microfluidic system. In exemplary embodiments, the bacteria gradually grew up along the printed alginate structure that had been placed into the culture, incorporating it.
    Type: Grant
    Filed: September 28, 2010
    Date of Patent: April 8, 2014
    Assignee: Virginia Tech Intellectual Properties, Inc.
    Inventors: Paul Gatenholm, Henrik Backdahl, Theodore Jon Tzavaras, Rafael V. Davalos, Michael B. Sano
  • Patent number: 8663392
    Abstract: Embodiments of the present invention overcome the well-known recalcitrance of lignocellulosic biomass in an economically viable manner. A process and a system are provided for the efficient fractionation of lignocellulosic biomass into cellulose, hemicellulose, and lignin. The cellulose and hemicellulose thus obtained are highly amorphous and can be readily converted into highly concentrated mixtures of five and six carbon sugars using known methods. Typical yields of sugars exceed 100 grams of sugars per liter of sugar solution. Other products, such as alcohols, can easily be prepared according to methods of the invention. The modest process conditions and low solvent/solid ratios of some embodiments of the invention require relatively low capital and processing costs.
    Type: Grant
    Filed: March 16, 2009
    Date of Patent: March 4, 2014
    Assignee: Virginia Tech Intellectual Properties, Inc.
    Inventor: Y. H. Percival Zhang
  • Publication number: 20140013808
    Abstract: A random array of holes is created in an optical fiber by gas generated during fiber drawing. The gas forms bubbles which are drawn into long, microscopic holes. The gas is created by a gas generating material such as silicon nitride. Silicon nitride oxidizes to produce nitrogen oxides when heated. The gas generating material can alternatively be silicon carbide or other nitrides or carbides. The random holes can provide cladding for optical confinement when located around a fiber core. The random holes can also be present in the fiber core. The fibers can be made of silica. The present random hole fibers are particularly useful as pressure sensors since they experience a large wavelength dependant increase in optical loss when pressure or force is applied.
    Type: Application
    Filed: September 10, 2013
    Publication date: January 16, 2014
    Applicant: Virginia Tech Intellectual Properties, Inc
    Inventors: Jeong I. KIM, Daniel KOMINSKY, Gary PICKRELL, Ahmad SAFAAI-JAZI, Roger STOLEN, Anbo WANG
  • Patent number: 8624541
    Abstract: Regulating the speed of a two-phase switched reluctance machine (TPSRM) rotor includes selecting either a motoring mode or braking mode of operation for the TPSRM, regulating the rotor speed, when the motoring mode is selected, using a control signal cooperatively produced by a speed control feedback loop and a current control feedback loop; and regulating the rotor speed, when the braking mode is selected, using a control signal produced by the current control feedback loop without the cooperation of the speed control feedback loop. The speed control feedback loop uses an established speed control signal and a signal indicative of the rotor's speed to dynamically adjust a first parameter governing the control signal. The current control feedback loop uses an established current control signal and a signal indicative of the current flowing through a stator winding of the TPSRM to dynamically adjust a second parameter governing the control signal.
    Type: Grant
    Filed: May 1, 2012
    Date of Patent: January 7, 2014
    Assignee: Virginia Tech Intellectual Properties, Inc.
    Inventors: Krishnan Ramu, Keunsoo Ha, Sung-Yeul Park
  • Publication number: 20140001103
    Abstract: A rotor for flotation machines or flotation cells of flotation machines includes blades that are configured to provide improved bubble flow and bubble generation performance while also reducing the power requirements for rotating the rotor to generate bubble flow within a tank of a flotation cell used to generate froth. Embodiments of the rotor may also be configured to be smaller than conventional rotor designs, which may help reduce the costs of manufacturing the rotor or flotation machines using such embodiments of the rotor.
    Type: Application
    Filed: June 28, 2012
    Publication date: January 2, 2014
    Applicant: VIRGINIA TECH INTELLECTUAL PROPERTIES, INC
    Inventors: Roe-Hoan Yoon, Gerald Luttrell, Saad Ragab, Demetri Telionis, Abdel-Halim Said, Sanja Miskovic, Aaron Noble, Yihong Yang
  • Patent number: 8618162
    Abstract: The present invention includes insecticidal carbamates that are useful, for example, for the control of insects, such as mosquitoes, which can be used in applications where exposure to and/or contact with humans is likely. The insecticides of the present invention include phenyl N-methyl carbamates and compositions comprising them that exhibit species-selective inhibition of acetylcholinesterase (AChE) and are preferably toxic to mosquitoes but not humans. Of particular interest are compounds of Formula (I) and Formula (II): Compounds of Formula (I) and Formula (II) are especially suitable for insecticide treated nets and indoor residual spraying for mosquito control.
    Type: Grant
    Filed: January 26, 2012
    Date of Patent: December 31, 2013
    Assignee: Virginia Tech Intellectual Properties, Inc.
    Inventors: Paul Carlier, Jeffrey Bloomquist, Sally Paulson, Eric Wong
  • Patent number: 8618761
    Abstract: A method for collecting operational parameters of a motor may include controlling the energization of a phase winding of the motor to establish an operating point, monitoring operational parameters of the motor that characterize a relationship between the energization control applied to the motor's phase winding and the motor's response to this control, and collecting information of the operational parameters for the operating point that characterizes the relationship between the applied energization control and the motor's response. The collected information characterizing the relationship between the applied energization control and the motor's response may be employed by a neural network to estimate the regions of operation of the motor. And a system for controlling the operation of motor may employ this information, the neural network, or both to regulate the energization of a motor's phase winding during a phase cycle.
    Type: Grant
    Filed: November 15, 2011
    Date of Patent: December 31, 2013
    Assignee: Virginia Tech Intellectual Properties, Inc.
    Inventors: Christopher Allen Hudson, Nimal Lobo, Krishnan Ramu