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Quantifying spatiotemporal variability in occupant exposure to an indoor airborne contaminant with an uncertain source location

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Building Simulation 2023年第6期16卷 889-913页

作者： john e.castellini jr.cary a.faulkner Wangda Zuo Michael D.Sohn Department of Mechanical engineering University of Colorado BoulderUCB 427BoulderCO80309USA Department Architectural engineering The Pennsylvania State UniversityUniversity ParkPA16802USA National Renewable energy National Laboratory GoldenCO80401USA energy Analysis and environmental Impacts Division Lawrence Berkeley National Laboratory1 Cyclotron RoadBerkeleyCA94720USA

Well-mixed zone models are often employed to compute indoor air quality and occupant *** effective,a potential downside to assuming instantaneous,perfect mixing is underpredicting exposures to high intermittent concentrations within a *** such cases are of concern,more spatially resolved models,like computational-fluid dynamics methods,are used for some or all of the ***,these models have higher computational costs and require more input information.A preferred compromise would be to continue with a multi-zone modeling approach for all rooms,but with a better assessment of the spatial variability within a *** do so,we present a quantitative method for estimating a room’s spatiotemporal variability,based on influential room *** proposed method disaggregates variability into the variability in a room’s average concentration,and the spatial variability within the room relative to that *** enables a detailed assessment of how variability in particular room parameters impacts the uncertain occupant *** demonstrate the utility of this method,we simulate contaminant dispersion for a variety of possible source *** compute breathing-zone exposure during the releasing(source is active)and decaying(source is removed)*** CFD methods,we found after a 30 minutes release the average standard deviation in the spatial distribution of exposure was approximately 28%of the source average exposure,whereas variability in the different average exposures was lower,only 10%of the total *** also find that although uncertainty in the source location leads to variability in the average magnitude of transient exposure,it does not have a particularly large influence on the spatial distribution during the decaying period,or on the average contaminant removal *** systematically characterizing a room’s average concentration,its variability,and the spatial variability within the room important insights can be gain

关键词： uncertainty variability airborne contaminant spatiotemporal variability well-mixed heterogeneity

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Fast prediction of indoor airflow distribution inspired by synthetic image generation artificial intelligence

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Building Simulation 2023年第7期16卷 1219-1238页

作者： cary a.faulkner Dominik S.Jankowski john e.castellini jr Wangda Zuo Philipp epple Michael D.Sohn Ali Taleb Zadeh Kasgari Walid Saad Department of Mechanical engineering University of Colorado BoulderBoulderCOUSA HySON Institut SonnebergGermany Department of Architectural engineering Pennsylvania State UniversityUniversity ParkPAUSA Department of Mechanical engineering Coburg University of Applied SciencesCoburgGermany energy Analysis and environmental Impacts Division Lawrence Berkeley National LaboratoryBerkeleyCAUSA Department of electrical and Computer engineering Virginia TechArlingtonVAUSA

Prediction of indoor airflow distribution often relies on high-fidelity,computationally intensive computational fluid dynamics(CFD)*** intelligence(Al)models trained by CFD data can be used for fast and accurate prediction of indoor airflow,but current methods have limitations,such as only predicting limited outputs rather than the entire flow ***,conventional Al models are not always designed to predict different outputs based on a continuous input range,and instead make predictions for one or a few discrete *** work addresses these gaps using a conditional generative adversarial network(CGAN)model approach,which is inspired by current state-of-the-art Al for synthetic image *** create a new Boundary Condition CGAN(BC-CGAN)model by extending the original CGAN model to generate 2D airflow distribution images based on a continuous input parameter,such as a boundary ***,we design a novel feature-driven algorithm to strategically generate training data,with the goal of minimizing the amount of computationally expensive data while ensuring training quality of the Al *** BC-CGAN model is evaluated for two benchmark airflow cases:an isothermal lid-driven cavity flow and a non-isothermal mixed convection flow with a heated *** also investigate the performance of the BC-CGAN models when training is stopped based on different levels of validation error *** results show that the trained BC-CGAN model can predict the 2D distribution of velocity and temperature with less than 5%relative error and up to about 75,ooo times faster when compared to reference CFD *** proposed feature-driven algorithm shows potential for reducing the amount of data and epochs required to train the Al models while maintaining prediction accuracy,particularly when the flow changes non-linearlywith respectto an input.

关键词： artificial intelligence indoor airflow conditional generative adversarial network computational fluid dynamics

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2024 Adult Compendium of Physical Activities:A third update of the energy costs of human activities

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Journal of Sport and Health Science 2024年第1期13卷 6-12页

作者： Stephen D.Herrmann erik A.Willis Barbara e.Ainsworth Tiago V.Barreira Mary Hastert Chelsea L.Kracht john M.Schuna jr. Zhenghui Cai Minghui Quan Catrine Tudor-Locke Melicia C.Whitt-Glover David R. Jacobs jr. Kansas Center for Metabolism and Obesity Research University of Kansas Medical CenterKansas CityKS 66160USA Division of Physical Activity and Weight Management Department of Internal MedicineUniversity of Kansas Medical CenterKansas CityKS 66160USA Center for Health Promotion and Disease Prevention University of North Carolina at Chapel HillChapel HillNC 27599USA College of Health Solutions Arizona State UniversityPhoenixAZ 85003USA School of exercise and Health Shanghai University of SportShanghai 200438China exercise Science Department Syracuse UniversitySyracuseNY 13244USA Clinical Sciences Division Pennington Biomedical Research CenterBaton RougeLA 70808USA School of exercise and Sport Science Oregon State UniversityCorvallisOR 97331USA College of Health and Human Services University of North Carolina at CharlotteCharlotteNC 28223USA Gramercy Research Group KnightdaleNC 27545USA Division of epidemiology and Community Health School of Public HealthUniversity of MinnesotaMinneapolisMN 55454USA

Background:The Compendium of Physical Activities was published in 1993 to improve the comparability of energy expenditure values assigned to self-reported physical activity(PA)across *** original version was updated in 2000,and again in 2011,and has been widely used to support PA research,practice,and public health ***:This 2024 update was tailored for adults 19-59 years of age by removing data from those≥60 *** a systematic review and supplementary searches,we identified new activities and their associated measured metabolic equivalent(MeT)values(using indirect calorimetry)published since *** replaced estimated MeTs with measured values when ***:We screened 32,173 abstracts and 1507 full-text papers and extracted 2356 PA energy expenditure values from 701 *** added303 new PAs and adjusted 176 existing MeT values and descriptions to reflect the addition of new data and removal of MeTs for older *** added a Major Heading(Video Games).The 2024 Adult Compendium includes 1114 PAs(912 with measured and 202 with estimated values)across 22 Major ***:This comprehensive update and refinement led to the creation of The 2024 Adult Compendium,which has utility across research,public health,education,and healthcare domains,as well as in the development of consumer health *** new website with the complete lists of PAs and supporting resources is available at https://***.

关键词： Adults energy expenditure exercise MeT Physical Activities

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Older Adult Compendium of Physical Activities:energy costs of human activities in adults aged 60 and older

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Journal of Sport and Health Science 2024年第1期13卷 13-17,F0003页

作者： erik A.Willis Stephen D.Herrmann Mary Hastert Chelsea L.Kracht Tiago V.Barreira john M.Schuna jr. Zhenghua Cai Minghui Quan Scott A.Conger Wendy J.Brown Barbara e.Ainsworth Center for Health Promotion and Disease Prevention University of North Carolina at Chapel HillChapel HillNC 27599USA Kansas Center for Metabolism and Obesity Research The University of Kansas Medical CenterKansas CityKS 66160USA Division of Physical Activity and Weight Management Department of Internal MedicineUniversity of Kansas Medical CenterKansas CityKS 66160USA Clinical Science Division Pennington Biomedical Research CenterBaton RougeLA 70808USA exercise Science Department Syracuse UniversitySyracuseNY 13244USA School of exercise&Sport Science Oregon State UniversityCorvallisOR 97331USA School of exercise and Health Shanghai University of SportShanghai 200438China Department of Kinesiology Boise State UniversityBoiseID 83725USA School of Human Movement and Nutrition Sciences The University of QueenslandSt.LuciaQLD 4072Australia Faculty of Health Sciences and Medicine Bond UniversityGold CoastQLD 4229Australia College of Health Solutions Arizona State UniversityPhoenixAZ 85003USA

Purpose:To describe the development of a Compendium for estimating the energy costs of activities in adults>60 years(OA Compendium).Methods:Physical activities(PAs)and their metabolic equivalent of task(MeT)values were obtained from a systematic search of studies published in 4 sport and exercise databases(PubMed,embase,SPORTDiscus(eBSCOhost),and Scopus)and a review of articles included in the 2011 Adult Compendium that measured PA in older *** values were computed as the oxygen cost(VO_(2),mL/kg/min)during PA divided by 2.7 m L/kg/min(MeT_(60+))to account for the lower resting metabolic rate in older ***:We identified 68 articles and extracted energy expenditure data on 427 *** these,we derived 99 unique Specific Activity codes with corresponding MeT_(60+)values for older *** developed a website to present the OA Compendium MeT_(60+)values:https://***:The OA Compendium uses data collected from adults>60 years for more accurate estimation of the energy cost of PAs in older *** is an accessible resource that will allow researchers,educators,and practitioners to find MeT_(60+)values for older adults for use in PA research and practice.

关键词： energy expenditure exercise MeT Older adults

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Can a multistage approach improve individual tree mortality predictions across the complex mixed-species and managed forests of eastern North America?

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Forest ecosystems 2023年第1期10卷 21-30页

作者： Cen Chen john Kershaw jr Aaron Weiskittel elizabeth McGarrigle Center for Research on Sustainable Forests University of MaineOronoME04469USA Faculty of Forestry&environmental Management University of New BrunswickFrederictonNBE3B 5A3Canada Nova Scotia Department of Natural Resources HalifaxNSB3J 3M8Canada

Tree mortality plays a fundamental role in the dynamics of forest ecosystems,yet it is one of the most difficult phenomena to accurately *** modeling strategies have been developed to improve individual tree mortality *** less explored strategy is the use of a multistage modeling *** improvements from this approach have remained largely *** this study,we developed a novel multistage approach and compared its performance in individual tree mortality predictions with a more conventional approach using an identical individual tree mortality model *** permanent plot data(n=9442)covering the Acadian Region of North America and over multiple decades(1965–2014)were used in this *** results indicated that the model behavior with the multistage approach better depicted the observed mortality and showed a notable improvement over the conventional *** difference between the observed and predicted numbers of dead trees using the multistage approach was much smaller when compared with the conventional *** addition,tree survival probabilities predicted by the multistage approach generally were not significantly different from the observations,whereas the conventional approach consistently underestimated mortality across species and overestimated tree survival probabilities over the large range of DBH in the *** new multistage approach also predictions of zero mortality in individual plots,a result not possible in conventional ***,the new approach was more tolerant of modeling errors because it based estimates on ranked tree mortality rather than error-prone predicted ***,this new multistage approach deserves to be considered and tested in future studies.

关键词： Tree mortality modeling Mortality disaggregation Mixed effect model Annualization Mixed forests

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Ancient Muses: Archaeology and the Arts

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2003年

作者： john H. Jameson jr

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Computational fluid dynamics simulation on the longwall gob breathing

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International Journal of Mining Science and Technology 2017年第2期27卷 185-189页

作者： Samuel A.Lolon Jürgen F.Brune Gregory e.Bogin jr. john W.Grubb Saqib A.Saki Aditya Juganda Department of Mining engineering Colorado School of MinesCO 80401USA Department of Mechanical engineering Colorado School of Mines CO 80401USA

In longwall mines, atmospheric pressure fluctuations can disturb the pressure balance between the gob and the ventilated working area, resulting in a phenomenon known as ‘‘gob breathing". Gob breathing triggers gas flows across the gob and the working areas and may result in a condition where an oxygen deficient mixture or a methane accumulation in the gob flows into the face area. Computational Fluid Dynamics(CFDs) modeling was carried out to analyze this phenomenon and its impact on the development of an explosive mixture in a bleeder-ventilated panel scheme. Simulation results indicate that the outgassing and ingassing across the gob and the formation of explosive Gas Zones(eGZs) are directly affected by atmospheric pressure changes. In the location where methane zones interface with mine air, eGZ fringes may form along the face and in the bleeder entries. These findings help assess the methane ignition and explosion risks associated with fluctuating atmospheric pressures.

关键词：计算流体力学模拟采空区呼吸爆炸性气体计算流体动力学大气压力长壁开采压力平衡

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Prospects for the continued development of environmentally-realistic toxicity test susing microorganisms

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Journal of environmental Sciences 1993年第3期5卷 253-268页

作者： john Cairns,jr. Paul V.McCormick Scott e.Belanger Department of Biology and University Center for environmental and Hazardous Materials Studies Virginia Polytechnic Institute and State UniversityBlacksburgVirginia 24061-0415U.S.A. Department of Biology Elizabethtown CollegeElizabethtownPennsylvania-17022-2298U.S.A.and Senior Research AssociateUniversity Center for Environmental and Hazardous Materials StudiesVirginia Polytechnic Institute and State UniversityBlacksburgVirginia-24061-0415U.S.A. Stream ecosystem Research Section Environmental Safety DepartmentThe Procter and Gamble CompanyCincinnatiOhio-45217U.S.A.

The focus of environmental regulations has changed significantly since the introduction of the bioassay as a standard means of assessing environmental *** in this change is an increasing emphasis on protecting the integrity of natural ecosystems,which incorporate community-and system-level properties as well as organismal and population ***,support for the use of multispecies testing has widened to include not only ecologists in academia but environmental scientists in the regulatory and industrial sector as *** reason for this trend is clear:the additional environmental realism gained from tests utilizing communities of organisms allows for greater insight into the potential hazard of chemicals and other forms of human activity to natural ecosystems that cannot be obtained from single species tests *** of the problems cited for multispecies testing early in their evolution as a hazard assessment tool have been refuted or *** particular,the use of natural microbial communities minimizes several shortcomings typically associated with multispecies toxicity *** discussion includes the utility of microcosm and mesocosm tests using aquatic microbial communities as hazard assessment tools in conjunction with accumulating information on their performance in toxicity testing *** increasing body of experimental evidence supports an expansion in the use of these tests for a variety of regulatory and research purposes.A shift in research focus is needed,however,to answer remaining questions and further refine standard protocols for these valuable ecotoxicological tools.

关键词： environmentally-realistic toxicity tests microorganisms.

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Dendroclimatic analysis of white pine (Pinus strobus L.)using long-term provenance test sites across eastern North America

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Forest ecosystems 2018年第3期5卷 221-235页

作者： Sophan Chhin Ronald S.Zalesny jr William C.Parker john Brissette Division of Forestry and Natural Resources West Virginia University322 Percival HallPO Box 6125MorgantownWV26506USA USDA Forest Service Northern Research Station5985Highway KRhinelanderWI 54501USA Ontario Forest Research Institute 1235Queen St.ESault Ste.MarieON P6A 2E5Canada USDA Forest Service Northern Research Station271Mast RoadDurhamNH 03824USA

Background: The main objective of this study was to examine the climatic sensitivity of the radial growth response of 13 eastern white pine(Pinus strobus L.) provenances planted at seven test sites throughout the northern part of the species’ native distribution in eastern North ***: The test sites(i.e., Wabeno, Wisconsin, USA; Manistique, Michigan, USA; Pine River, Michigan, USA; Newaygo,Michigan, USA; Turkey Point, Ontario, Canada; Ganaraska, Ontario, Canada; and Orono, Maine, USA) examined in this study were part of a range-wide white pine provenance trial established in the early 1960 s in the eastern United States and Canada. Principal components analysis(PCA) was used to examine the main modes of variation [first(PC1) and second(PC2) principal component axes] in the standardized radial growth indices of the provenances at each test *** year scores for PC1 and PC2 were examined in relation to an array of test site climate variables using multiple regression analysis to examine the commonality of growth response across all provenances to the climate of each test site. Provenance loadings on PC1 and PC2 were correlated with geographic parameters(i.e., latitude, longitude,elevation) and a suite of biophysical parameters associated with provenance origin ***: The amount of variation in radial growth explained by PC1 and PC2 ranged from 43.4% to 89.6%. Dendroclimatic models revealed that white pine radial growth responses to climate were complex and differed among sites. The key dendroclimatic relationships observed included sensitivity to high temperature in winter and summer, cold temperature in the spring and fal(i.e., beginning and end of the growing season), summer moisture stress, potential sensitivity to storminduced damage in spring and fal, and both positive and negative effects of higher winter snowfal. Separation of the loadings of provenances on principal component axes was mainly associated with temperature-related bioclima

关键词： Adaptation Climate change Dendrochronology Seed source

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engineering electromagnetics / 6th ed.

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丛书名： McGraw-Hill series in electrical engineering

2001年

作者： William H. Hayt jr. john A. Buck.

Includes index.

ISBN: (纸本)0072304243

Includes index.

关键词： electromagnetic theory.

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