Patents Assigned to Virginia Tech
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Patent number: 8811039Abstract: 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: GrantFiled: July 18, 2011Date of Patent: August 19, 2014Assignee: Virginia Tech Intellectual Properties, Inc.Inventors: Khai Doan The Ngo, Xiao Cao, Yin Wang
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Patent number: 8811700Abstract: 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: GrantFiled: April 15, 2010Date of Patent: August 19, 2014Assignee: Virginia Tech Intellectual Properties, Inc.Inventors: Ge Wang, Hengyong Yu
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Patent number: 8803489Abstract: 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: GrantFiled: July 18, 2011Date of Patent: August 12, 2014Assignee: Virginia Tech Intellectual Properties, Inc.Inventors: Qian Li, Fred C. Lee, Ming Xu, Chuanyun Wang
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Publication number: 20140220067Abstract: 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: ApplicationFiled: February 6, 2014Publication date: August 7, 2014Applicant: Virginia Tech Intellectual Properties, Inc.Inventors: Xiang-Jin MENG, Nathan M. Beach, Sheela Ramamoorthy
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Patent number: 8798722Abstract: 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: GrantFiled: March 1, 2010Date of Patent: August 5, 2014Assignee: Virginia Tech Intellectual Properties, Inc.Inventors: Christopher Rylander, Thomas A. Campbell, Ge Wang, Yong Xu, Mehmet Alpaslan Kosoglu
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Publication number: 20140210282Abstract: 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: ApplicationFiled: August 16, 2013Publication date: July 31, 2014Applicant: Virginia Tech Intellectual Properties, Inc.Inventors: Dong Dong, Dushan Boroyevich, Paolo Mattavelli
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Publication number: 20140212283Abstract: 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: ApplicationFiled: August 27, 2012Publication date: July 31, 2014Applicant: VIRGINIA TECH INTELLECTUAL PROPERTIES, INC.Inventors: R. Gordon Kirk, Willliam Songer
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Patent number: 8785376Abstract: 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: GrantFiled: December 20, 2011Date of Patent: July 22, 2014Assignees: Virginia Tech Intellectual Properties, University of Utah Research FoundationInventors: Eric W. Schmidt, Joseph O. Falkinham, Peter W. Jeffs
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Patent number: 8784566Abstract: 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: GrantFiled: March 29, 2006Date of Patent: July 22, 2014Assignee: Virginia Tech Intellectual Properties, Inc.Inventor: Y. H. Percival Zhang
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Publication number: 20140190471Abstract: 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: ApplicationFiled: March 19, 2014Publication date: July 10, 2014Applicant: Virginia Tech Intellectual Properties, Inc.Inventor: Y. H. Percival Zhang
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Publication number: 20140187681Abstract: 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: ApplicationFiled: December 31, 2012Publication date: July 3, 2014Applicant: Virginia Tech Intellectual Properties, Inc.Inventors: Colin SMITH, Shashank Priya
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Patent number: 8700257Abstract: 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: GrantFiled: May 13, 2010Date of Patent: April 15, 2014Assignees: Toyota Motor Engineering & Manufacturing North America, Inc., Virginia Tech Intellectual Properties, Inc.Inventors: Atsutaka Tamura, Stefan Duma
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Patent number: 8698579Abstract: 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: GrantFiled: March 25, 2011Date of Patent: April 15, 2014Assignee: Virginia Tech Intellectual Properties, Inc.Inventors: Shuo Wang, Fred C. Lee
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Patent number: 8691974Abstract: 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: GrantFiled: September 28, 2010Date of Patent: April 8, 2014Assignee: Virginia Tech Intellectual Properties, Inc.Inventors: Paul Gatenholm, Henrik Backdahl, Theodore Jon Tzavaras, Rafael V. Davalos, Michael B. Sano
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Patent number: 8663392Abstract: 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: GrantFiled: March 16, 2009Date of Patent: March 4, 2014Assignee: Virginia Tech Intellectual Properties, Inc.Inventor: Y. H. Percival Zhang
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Publication number: 20140013808Abstract: 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: ApplicationFiled: September 10, 2013Publication date: January 16, 2014Applicant: Virginia Tech Intellectual Properties, IncInventors: Jeong I. KIM, Daniel KOMINSKY, Gary PICKRELL, Ahmad SAFAAI-JAZI, Roger STOLEN, Anbo WANG
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Patent number: 8624541Abstract: 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: GrantFiled: May 1, 2012Date of Patent: January 7, 2014Assignee: Virginia Tech Intellectual Properties, Inc.Inventors: Krishnan Ramu, Keunsoo Ha, Sung-Yeul Park
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Publication number: 20140001103Abstract: 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: ApplicationFiled: June 28, 2012Publication date: January 2, 2014Applicant: VIRGINIA TECH INTELLECTUAL PROPERTIES, INCInventors: Roe-Hoan Yoon, Gerald Luttrell, Saad Ragab, Demetri Telionis, Abdel-Halim Said, Sanja Miskovic, Aaron Noble, Yihong Yang
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Patent number: 8618162Abstract: 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: GrantFiled: January 26, 2012Date of Patent: December 31, 2013Assignee: Virginia Tech Intellectual Properties, Inc.Inventors: Paul Carlier, Jeffrey Bloomquist, Sally Paulson, Eric Wong
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Patent number: 8618761Abstract: 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: GrantFiled: November 15, 2011Date of Patent: December 31, 2013Assignee: Virginia Tech Intellectual Properties, Inc.Inventors: Christopher Allen Hudson, Nimal Lobo, Krishnan Ramu