Now showing items 371-390 of 491

    • Optimal trajectory control for LLC resonant converter for LED PWM dimming 

      Virginia Polytechnic Institute and State University; Lee, Fred C.; Ji, Shu; Feng, Weiyi (United States Patent and Trademark Office, 2016-03-01)
      Pulse width modulation is provided for controlling a resonant power converter, particularly for dimming of light emitting diode arrays without loss of efficiency. Dynamic oscillation due to the beginning of a pulse width ...
    • Optimal trajectory control for LLC resonant converter for soft start-up 

      Virginia Tech Intellectual Properties, Inc.; Lee, Fred C.; Feng, Weiyi (United States Patent and Trademark Office, 2016-04-19)
      By setting switching instants of a switching circuit of a resonant power converter based on current in a resonant circuit reaching a current limit of a current limitation band, soft start-up of the power converter can be ...
    • Optimization of segmented thermoelectric generator using Taguchi and ANOVA techniques 

      Kishore, Ravi Anant; Sanghadasa, Mohan; Priya, Shashank (Springer Nature, 2017-12-01)
      Recent studies have demonstrated that segmented thermoelectric generators (TEGs) can operate over large thermal gradient and thus provide better performance (reported efficiency up to 11%) as compared to traditional TEGs, ...
    • Origin of high piezoelectric response in A-site disordered morphotropic phase boundary composition of lead-free piezoelectric 0.93(Na0.5Bi0.5)TiO3-0.07BaTiO(3) 

      Maurya, Deepam; Murayama, M.; Pramanick, A.; Reynolds, W. T., Jr.; An, Ke; Priya, Shashank (American Institute of Physics, 2013-03-21)
      Perovskite piezoelectric compositions near the morphotropic phase boundary (MPB) are known to exhibit high piezoelectric response. In lead-based ABO(3) compound with B-site disorder, the origin of this enhancement has been ...
    • Outdoor grill and patio 

      Gottlieb, Lois Davidson (Virginia Tech. Digital Library and Archives; Virginia Tech. University Libraries. Special Collections Department, 2005-01-06)
    • Outdoor grill, patio, and wooded area 

      Gottlieb, Lois Davidson (Virginia Tech. Digital Library and Archives; Virginia Tech. University Libraries. Special Collections Department, 2005-01-06)
    • Overview: Risk of Falling and Older Adults 

      Center for Gerontology (Virginia Tech. Center for Gerontology, 2013-10)
      Falls are a major public health concern for older adults. Annually, 1 out of 3 Americans aged 65+ experiences a fall. According to the Centers for Disease Control and Prevention, falls are the leading cause of hospitalization ...
    • Parallel devices having balanced switching current and power 

      Virginia Tech Intellectual Properties, Inc.; Toyota Motor Engineering & Manufacturing North American, Inc.; Wang, Chi-Ming; Mao, Yincan; Miao, Zichen; Ngo, Khai D. (United States Patent and Trademark Office, 2018-10-30)
      A power circuit includes a power source for providing electrical power and two driving transistors being disposed in parallel and receiving electrical power from the power source. Each of the two driving transistors includes ...
    • Peptide-based hydrogen sulphide-releasing gels 

      Carter, Jennifer M.; Qian, Yun; Foster, Jeffrey C.; Matson, John B. (The Royal Society of Chemistry, 2015-07-20)
      An aromatic peptide amphiphile was designed for delivery of the signaling gas H2S. The peptide self-assembled in water into nanofibers that gelled upon charge screening. The non-toxic gel slowly released H2S over 15 hours, ...
    • Phase transition and temperature stability of piezoelectric properties in Mn-modified Pb(Mg1/3Nb2/3)O-3-PbZrO3-PbTiO3 ceramics 

      Yan, Yongke; Kumar, Amit; Correa, Margarita; Cho, Kyung-Hoon; Katiyar, R. S.; Priya, Shashank (AIP Publishing, 2012-04-01)
      This study investigates the effect of two different Mn modifiers [MnO2 and Pb(Mn1/3Nb2/3)O-3(PMnN)] on the of phase transitions in Pb(Mg1/3Nb2/3)O-3-PbZrO3-PbTiO3 ceramics. The temperature dependence of polarization derived ...
    • Phosphonium-containing diblock copolymers from living anionic polymerization of 4-diphenylphosphino styrene 

      Schultz, Alison R.; Fahs, Gregory B.; Jangu, Chainika; Chen, Mingtao; Moore, Robert B.; Long, Timothy E. (The Royal Society of Chemistry, 2015-11-20)
      Living anionic polymerization of 4-diphenylphosphino styrene (DPPS) achieved well-defined homopolymers, poly(DPPS-b-S) styrenic block copolymers, and poly(I-b-DPPS) diene-based diblock copolymers with predictable molecular ...
    • Physical layer orthogonal frequency-division multiplexing acquisition and timing synchronization security 

      La Pan, Matthew J.; Clancy, Charles T.; McGwier, Robert W. (Wiley, 2014-08-18)
      Orthogonal frequency-division multiplexing (OFDM) has become the manifest modulation choice for 4G standards. Timing acquisition and carrier frequency offset synchronization are prerequisite to OFDM demodulation and must ...
    • Piecewise-Constant-Model-Based Interior Tomography Applied to Dentin Tubules 

      He, Peng; Wei, Biao; Wang, Steve; Stock, Stuart R.; Yu, Hengyong; Wang, Ge (Hindawi Publishing Corporation, 2013)
      Dentin is a hierarchically structured biomineralized composite material, and dentin's tubules are difficult to study in situ. Nano-CT provides the requisite resolution, but the field of view typically contains only a few ...
    • Piezoelectric and Magnetoelectric Thick Films for Fabricating Power Sources in Wireless Sensor Nodes 

      Priya, Shashank; Ryu, Jungho; Park, Chee-Sung; Oliver, Josiah; Choi, Jong-Jin; Park, Dong-Soo (MDPI, 2009-08-17)
      In this manuscript, we review the progress made in the synthesis of thick film-based piezoelectric and magnetoelectric structures for harvesting energy from mechanical vibrations and magnetic field. Piezoelectric compositions ...
    • Piezoelectric MEMS for energy harvesting 

      Kim, S. G.; Priya, S.; Kanno, I. (Cambridge University Press, 2012-11)
      Piezoelectric microelectromechanical systems (MEMS) have been proven to be an attractive technology for harvesting small magnitudes of energy from ambient vibrations. This technology promises to eliminate the need for ...
    • Piezoelectric properties and temperature stability of Mn-doped Pb(Mg1/3Nb2/3)-PbZrO3-PbTiO3 textured ceramics 

      Yan, Yongke; Cho, Kyung-Hoon; Priya, Shashank (AIP Publishing, 2012-03-01)
      In this letter, we report the electromechanical properties of textured 0.4Pb(Mg1/3Nb2/3) O-3-0.25PbZrO(3)-0.35PbTiO(3) (PMN-PZT) composition which has relatively high rhombohedral to tetragonal (R-T) transition temperature ...
    • Pond at the Gottlieb residence 

      Gottlieb, Mark (Virginia Tech. Digital Library and Archives; Virginia Tech. University Libraries. Special Collections Department, 2008-04-11)
      Mark Gottlieb, son of Lois Gottlieb, sent photos of a house designed by his mother. This home is in Fairfax Station, Virginia.
    • Power switch drivers with equalizers for paralleled switches 

      Virginia Tech Intellectual Properties, Inc.; Miao, Zichen; Ngo, Khai D.; Zhang, Lujie (United States Patent and Trademark Office, 2018-06-12)
      Capacitors connected between gate terminals of a plurality of parallel-connected power transistors are charged and discharged in each switching cycle to provide a plurality of power transistor control waveforms from a ...
    • Power-cell switching-cycle capacitor voltage control for modular multi-level converters 

      Virginia Tech Intellectual Properties, Inc.; Wang, Jun; Boroyevich, Dushan; Burgos, Rolando P.; Wen, Bo (United States Patent and Trademark Office, 2018-05-08)
      In a modular multi-level power converter, additional switching states are interleaved between main switching states that control output voltage or waveform. The additional switching states provide current from a DC-link ...