Browsing Research Centers by Title
Now showing items 479-498 of 624
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A Panel Discussion with Fred S. Keller
(Virginia Tech. Learning Resources Center, 1979-05) -
Parallel devices having balanced switching current and power
(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 ... -
Patient Views of Mild Cognitive Impairment
(Center for Gerontology, Virginia Tech, 2007-11) -
Peptide-based hydrogen sulphide-releasing gels
(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, ... -
Personal and Social Resources and Well Being among Informal Care Recipients
(Virginia Tech, 2004-07-31)Moving beyond a focus on primary caregivers only, we examined the effects on older adults’ psychological well-being of having multiple family or friend helpers and of other elements of social support when receiving informal ... -
Perturbation-based balance training targeting both slip- and trip-induced falls among older adults: a randomized controlled trial
(2020-06-12)Background Falls are the leading cause of injuries among older adults. Perturbation-based balance training (PBT) is an innovative approach to fall prevention that aims to improve the reactive balance response following ... -
Phase transition and temperature stability of piezoelectric properties in Mn-modified Pb(Mg1/3Nb2/3)O-3-PbZrO3-PbTiO3 ceramics
(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
(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
(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
(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
(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
(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
(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
(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. -
Porous organic materials offer vast future opportunities
(2020-10-02)In light of the surging research on porous organic materials, we herein discuss the key issues of their porous structures, surface properties, and end functions. We also present an outlook on emerging opportunities, new ... -
Power switch drivers with equalizers for paralleled switches
(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
(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 ... -
A Practical Guide for Managing Interdisciplinary Teams: Lessons Learned from Coupled Natural and Human Systems Research
(MDPI, 2020-07-09)Interdisciplinary team science is essential to address complex socio-environmental questions, but it also presents unique challenges. The scientific literature identifies best practices for high-level processes in team ... -
Predicting Community Connections in the Workplace
(Virginia Tech, 2003-11)This study explores the relationships between interpersonal connections in the workplace and four dimensions of employee retention. -
Predicting Mild Traumatic Brain Injury with Injury Risk Functions
(Brain Injuries and Biomechanics Symposium, 2013-09-19)To assess the safety of various products, equipment, and vehicles during traumatic events injury risk curves have been developed correlate measurable parameters with risk of injury. The first risk curves to predict head ...