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DEMAND-SIDE ENERGY MANAGEMENT AT THE univERSITY OF virginia

Journal of Green Building 2006年第3期1卷 58-68页

作者： Paul Crumpler university of virginia Facilities Management

INTRODUCTION The following text offers a view of the Energy Management Program at the university of virginia(UVa),located in Charlottesville,*** has a very successful history of conserving energy and improving efficiency in central energy systems such as chilled water loops and steam production and *** recently,the UVa Energy Management Program has intensified efforts on demand-side energy conservation ***-side conservation opportunities exist at most college campuses;improvements in efficiency in buildings(demand side)can significantly reduce energy consumption and *** keys to an effective demand-side energy management program are shown in the *** basic,continuous improvement cycle of PLAN-DO-CHECK-ACT was coined by Deming,and is the basis of energy management at *** and ongoing successful efforts at UVa have paid huge *** include elimination of many aging stand-alone chillers and boilers by connecting buildings to central *** energy use and cost has saved at least$10,000,000 ***-side improvements include lighting upgrades made in all buildings by replacing older T-12 fluorescent fixtures with T-8 tubes with electronic *** sensors were also added to thousands of lighting circuits.A major supply-side improvement was investing in four large electric substations to combine hundreds of electricity accounts into four,thus reducing cost and improving *** has hundreds of buildings with approximately 14 million square feet of enclosed building *** uses and types include a large teaching hospital,research buildings,animal care areas,laboratory,classroom,athletic,and student housing ranging in age from more than 200 years to new *** and utility use vary just as greatly as their ages and *** of how efficient a building is designed to be,it operates only as efficiently as it is allowed to be by building occupants and man

关键词： hundreds lighting SIDE

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Macroinvertebrate　assemblages　of　surface　mine　wetlands　of　Southwest　virginia，USA

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Journal of Environmental Sciences 1996年第1期8卷 1-14页

作者： David H.Jones Robert B. Atkinson John Cairns,Jr.(Department of Biology,virginia Polytechnic Institute and State university, Blacksburg,virginia 24061 USA) Dept Biol Virginia Poly Inst Blacksburg VA 24061 United States

The focus of this study was to investigate the macroinvertebrate community in surface mine wetlands. Nine wetlands were sampled for macroinvertebrates from July 1993 through May *** sites represented a range of physical,chemical, and biological parameters. Macroinvertebrates were found in all sites;a total of 14 orders, 40 families,and 70 genera were identified in the samples. Insects were the most common invertebrates,and most functional feeding groups were represented. Predators dominated with 63% of the taxa, followed by the collector/gathers with 20%,shredders 14%, and scrapers 3%. Sites differed in the number of taxa inhabiting *** ranged from 10 genera to *** lowest richness was found in two seasonal wetlands that were dry for the majority of the year. A permanently flooded site with no water quality problems and a dense growth of aquatic plants had the highest richness.

关键词： macroinvertebrate assemblages surface mine wetlands wetland faunas.

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CRITICAL ISSUES OF POWDER METALLURGY TURBINE DISKS

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Acta Metallurgica Sinica(English Letters) 1996年第6期9卷 467-471页

作者： K.M. Chang(Department of Mechanical and Aerospace Engineering,West virginia university, P.O. Box 6160, Morgantown,WV 26506, USA West virginia univ Morgantown United States

P/M superalloy disks obtain their final strength by appropriate heat treatments; the maximum attainable strength depends on the rapid cooling rate from the solution annealing. A rapid quench of a large disk forging can cause two problems, surface cracking and shape *** the past,many attempts employ the finite element code to model and to predict temperature evolution and induced stress distribution in a large turbine disk. The major difficulty was the correct description of alloy behavior; particularly the thermomechanical properties and the failure criteria of material during the cooling. High temperature fatigue resistance is always the key requirement for disk materials. New methodology of residual life management emphasizes the initiation as well as the propagation of the cracks developed under the service conditions. One of major challenges to P/M superalloys is the time-dependent behavior of fatigue cracking, which relates to the well-known SAGBO (stress-assisted grain boundary oxidation) phenomenon.A great effort has been done to understand the micro-mechanism of time-dependent fatigue crack propagation resulted in the second generation of P/M superalloys. Further improvement on temperature capability of disk alloys at rim area may lead to the idea of dual-property *** grain structures at different portions of a large disk are possible,as the property requirements for different locations are different. This goal is achievable if the thermal history at specific disk locations can be controlled to develop desirable microstructures and *** suggestions on the future direction of research efforts will be discused.

关键词： superalloy disk,powder metallurgy (P/M) quench cracking,fatigue crack propagation SAGBO (stress-assisted grain boundary oxidation),dual-property disk grain size

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An Analysis of Social Vulnerability to Natural Hazards in Nepal Using a Modified Social Vulnerability Index

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International Journal of Disaster Risk Science 2019年第1期10卷 103-116页

作者： Sanam K.Aksha Luke Juran Lynn M.Resler Yang Zhang Department of Geography Virginia Tech virginia Water Resources Research Center Virginia Tech Urban Affairs and Planning Virginia Tech

Social vulnerability influences the ability to prepare for, respond to, and recover from disasters. The identification of vulnerable populations and factors that contribute to their vulnerability are crucial for effective disaster risk reduction. Nepal exhibits multihazard risk and has experienced socioeconomic and political upheaval in recent decades, further increasing susceptibility to ***, we still know little regarding social vulnerability in Nepal. Here, we investigate social vulnerability in Nepal by adapting Social Vulnerability Index(SoVI) methods to the Nepali context. Variables such as caste, and populations who cannot speak/understand Nepali were added to reflect the essence of the Nepali context. Using principal component analysis, 39 variables were reduced to seven factors that explained 63.02% of variance in the *** scores were summarized to calculate final SoVI scores. The highest levels of social vulnerability are concentrated in the central and western Mountain, western Hill, and central and eastern Tarai regions of Nepal, while the least vulnerable areas are in the central and eastern Hill regions. These findings, supplemented with smaller-scale analyses, have the potential to assist village officers, policymakers,and emergency managers in the development of more effective and geographically targeted disaster management programs.

关键词： Disaster risk reduction Natural hazards Nepal Principal component analysis Social Vulnerability Index

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Harnessing wrinkling morphologies of graphene on soft substrates for mechanically programmable interfacial thermal conductance

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Nano Research 2023年第7期16卷 9608-9617页

作者： Qingchang Liu Baoxing Xu Department of Mechanical and Aerospace Engineering University of VirginiaCharlottesvilleVirginia 22904USA

Strain engineering has been leveraged to tune the thermal properties of materials by introducing stress and manipulating local atomic vibrations,which poses a detrimental threat to the mechanical integrity of materials and structures and limits the capability to regulate thermal ***,we report that the interfacial thermal conductance of graphene on a soft substrate can be regulated by harnessing wrinkling and folding morphologies of graphene,which could be well controlled by managing the prestrain applied to the *** obtained graphene structures are free of significant in-plane mechanical strain and only have infinitesimal distortion to the intrinsic thermal properties of *** subsequent thermal transport studies with pumpprobe non-equilibrium molecular dynamics(MD)simulation show that the thermal conductance between graphene structures and the substrate is uniquely determined by the morphological features of *** atomic density of interfacial interactions,energy dissipation,and temperature distribution are elucidated to understand the thermal transport across each graphene structure and *** further demonstrate that the normalized thermal conductance decreases monotonically with the increase of the equivalent mechanical strain,showing the capability of mechanically programmable interfacial thermal conductance in a broad range of *** demonstrations in search of on-demand thermal conductance are conducted by controlling the geometric morphologies of *** study lays a foundation for regulating interfacial thermal conductance through mechanical loading-induced geometric deformation of materials on a soft substrate,potentially useful in the design of flexible and stretchable structures and devices with tunable thermal management performance.

关键词： interfacial thermal conductance wrinkled graphene pump-probe atomic interaction mechanical loading

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Extinctions,Morphological Gaps,Major Transitions,Stem Groups,and the Origin of Major Clades,with a Focus on Early Animals

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Acta Geologica Sinica(English Edition) 2022年第6期96卷 1821-1829页

作者： XIAO Shuhai Department of Geosciences Virginia TechBlacksburgVirginia 24061USA

Systematic extinctions can leave major morphological gaps between living crown-group *** morphological gaps would be perceived,from a neontological point of view,as major evolutionary *** order to fill these morphological gaps and to map the evolutionary steps toward major evolutionary transitions,we need to integrate extinct stem-group taxa in phylogenetic ***,the recognition of stem group has not been widely adopted in the study of early animal fossils,despite that all fossils are stem groups at one level or *** of the difficulty is that stem groups may not have all features that collectively diagnose the respective crown group,and they can have unique(autapomorphic)features,making them tantalizingly similar to and frustratingly different from the crown group(e.g.,stemgroup eukaryotes can be prokaryotic and stem-group animals can be protistan).The need to embrace stem groups and to implement the PhyloCode,in order to achieve phylogenetic clarity and to offer key paleontological insights into the origin and early animal evolution,is illustrated in debates on several controversial Ediacaran and Cambrian fossils.

关键词： metazoan Ediacaran Cambrian evolutionary radiation stem group crown group

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A Survey and Tutorial of EEG-Based Brain Monitoring for Driver State Analysis

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IEEE/CAA Journal of Automatica Sinica 2021年第7期8卷 1222-1242页

作者： Ce Zhang Azim Eskandarian virginia Tech Mechanical Engineering Department ASIM Lab Virginia 24061-0131 USA

The driver’s cognitive and physiological states affect his/her ability to control the ***,these driver states are essential to the safety of *** design of advanced driver assistance systems(ADAS)or autonomous vehicles will depend on their ability to interact effectively with the driver.A deeper understanding of the driver state is,therefore,***(EEG)is proven to be one of the most effective methods for driver state monitoring and human error *** paper discusses EEG-based driver state detection systems and their corresponding analysis algorithms over the last three ***,the commonly used EEG system setup for driver state studies is ***,the EEG signal preprocessing,feature extraction,and classification algorithms for driver state detection are ***,EEG-based driver state monitoring research is reviewed in-depth,and its future development is *** is concluded that the current EEGbased driver state monitoring algorithms are promising for safety ***,many improvements are still required in EEG artifact reduction,real-time processing,and between-subject classification accuracy.

关键词： Advanced driver assistance systems(ADAS) data analysis electroencephalography(EEG) intelligent vehicles machine learning algorithms neural network.

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OPTIMAL INVERSE LQG CONTROL FOR CERTAIN ODE AND PDE STATIONARY PROCESSES

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Journal of Systems Science & Complexity 2010年第3期23卷 584-599页

作者： David L.RUSSELL Department of Mathematics Virginia Tech

Following work carried out earlier on linear-quadratic optimal control for linear finitedimensional stationary systems we report,in this article,on extension of some of those results to certaininfinite dimensional systems;in particular a class of PDE systems of elliptic *** systems arestudied in the now familiar framework developed by *** and ***,specialized to asubclass of such systems important in a variety of *** an extended example this paperstudies an optimal redistribution problem in a groundwater flow system governed by Darcy's equation,presenting both analytic and computational work related to such problems.

关键词： Elliptic PDE linear feedback control stationary system.

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Rapid, cost-effective DNA quantification via a visuallydetectable aggregation of superparamagnetic silicamagnetite nanoparticles

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Nano Research 2014年第5期7卷 755-764页

作者： Qian Liu Jingyi Li Hongxue Liu Ibrahim Tora Matthew S. Ide Jiwei Lu Robert J. Davis David L. Green James P. Landers Department of Chemistry University of Virginia McCormick Road P. O. Box 400319 Charlottesville 22904 Virginia USA Department of Pathology University of Virginia Health Science Center Charlottesville 22908 Virginia USA Department of Mechanical Engineering University of Virginia Charlottesville 22904 Virginia USA Center for Microsystems forthe Life Sciences University of Virginia Charlottesville 22904 Virginia USA Department of Materials Science & Engineering University of Virginia P. O. Box 400745 395 McCormick Road Charlottesville 22904-4745 Virginia USA Department of Chemical Engineering University of Virginia. 123 Engineers Way Charlottesville 22904 Virginia USA

DNA and silica-coated magnetic particles entangle and form visible aggregates under chaotropic conditions with a rotating magnetic field, in a manner that enables quantification of DNA by image analysis. As a means of exploring the mechanism of this DNA quantitation assay, nanoscale SiO2-coated Fe304 （Fe3O4@SiO2） particles are synthesized via a solvothermal method. Characterization of the particles defines them to be -200 nm in diameter with a large surface area （141.89 m2/g）, possessing superparamagnetic properties and exhibiting high saturation magnetization （38 emu/g）. The synthesized Fe3O4@SiO2 nanoparticles are exploited in the DNA quantification assay and, as predicted, the nanoparticles provide better sensitivity than commercial microscale Dynabeads for quantifying DNA, with a detection limit of 4 kilobase-pair fragments of human DNA. Their utility is proven using nanoparticle DNA quantification to guide efficient polymerase chain reaction （PCR） amplification of short tandem repeat loci for human identification.

关键词： silica/magnetite core-shell superparamagnetic DNA quantification polymerase chain reaction(PCR)

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Leaching recovery of rare earth elements from the calcination product of a coal coarse refuse using organic acids

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Journal of Rare Earths 2022年第2期40卷 318-327,I0005页

作者： Bin Ji Qi Li Wencai Zhang Department of Mining and Minerals Engineering Virginia Polytechnic Institute and State UniversityBlacksburg Virginia 24061USA

Due to the increasing criticality of rare earth elements(REEs),it has become essential to recover REEs from alternative *** this study,systematic REEs leaching tests were performed on the calcination product of a coal coarse refuse using hydrochloric acid and different types of organic acid as *** results show that the recovery of REEs,especially heavy REEs(HREEs)and scandium(Sc),is improved by using selected organic *** acid and DL-malic acid afford the best leaching performances;whereas,malonic acid,oxalic acid,and DL-tartaric acid are inferior to hydrochloric *** of zeta potential measurements and solution chemical equilibrium calculations show that malonic acid is more likely adsorbed on the surface of the calcined material compared with citric acid and DL-malic *** adsorption may reduce the effective concentration of malonic species in solution and/or increase the amount of REEs adsorbed on the surface,thereby impairing the leaching *** with light REEs(LREEs),a stronger adsorption of the HREEs on the surface is observed from electro-kinetic test *** finding explains why organic acids impose a more positive impact on the leaching recovery of HREEs,By complexing with the HREEs,organic acids can keep the metal ions in solution and improve the leaching *** adsorption of Sc^(3+)on the surface is the lowest compared with other ***,rather than complexing,the organic anionic species likely play a function of solubilizing Sc from the solid,which is similar to that of hydrogen ions.

关键词： Rare earth elements Coal refuse Acid leaching Organic acids

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