检索结果-南通市图书馆

A practical application of photogrammetry to performing rib characterization measurements in an underground coal mine using a DSLR camera

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2017年第1期27卷 83-90页

作者： brent A.Slaker Khaled M.Mohamed Mining Engineer Ground Control Branch NIOSH Office of Mine Safety and Health ResearchPittsburghPAUSA

Understanding coal mine rib behavior is important for inferring pillar loading conditions as well as ensuring the safety of miners who are regularly exposed to ribs. Due to the variability in the geometry of underground openings and ground behavior, point measurements often fail to capture the true movement of mine workings. Photogrammetry is a potentially fast, cheap, and precise supplemental measurement tool in comparison to extensometers, tape measures, or laser range meters, but its application in underground coal has been limited. The practical use of photogrammetry was tested at the Safety Research Coal Mine, National Institute for Occupational Safety and Health(NIOSH). A commercially available, digital single-lens reflex(DSLR) camera was used to perform the photogrammetric surveys for the experiment. Several experiments were performed using different lighting conditions, distances to subject,camera settings, and photograph overlaps, with results summarized as follows: the lighting method was found to be insignificant if the scene was appropriately illuminated. It was found that the distance to the subject has a minimal impact on result accuracy, and that camera settings have a significant impact on the photogrammetric quality of images. An increasing photograph resolution was preferable when measuring plane orientations; otherwise a high point cloud density would likely be excessive. Focal ratio(F-stop) changes affect the depth of field and image quality in situations where multiple angles are necessary to survey cleat orientations. Photograph overlap is very important to proper three-dimensional reconstruction, and at least 60% overlap between photograph pairs is ideal to avoid unnecessary post-processing. The suggestions and guidelines proposed are designed to increase the quality of photogrammetry inputs and outputs as well as minimize processing time, and serve as a starting point for an underground coal photogrammetry study.

关键词： Photogrammetry Coal mining Underground Rib characterization

Assessing ventilation control strategies in underground parking garages

在线全文

学校读者我要写书评

暂无评论

Building Simulation 2021年第3期14卷 701-720页

作者： Afshin Faramarzi Jongki Lee brent Stephens Mohammad Heidarinejad Department of Civil Architecturaland Environmental EngineeringIllinois Institute of TechnologyChicagoILUSA

Enclosed parking garages require mechanical ventilation fans to dilute concentrations of pollutants emitted from vehicles,which contributes to energy use and peak electricity *** study develops and applies a simulation framework combining multi-zone airflow and contaminant transport modeling,fan affinity laws,and realistic assumptions for vehicle traffic patterns and carbon monoxide(CO)emissions to improve our ability to predict the impacts of various ventilation control strategies on indoor air quality and fan energy use in parking *** simulation approach is validated using measured data from a parking garage case study and then applied to investigate fan energy use,peak power demand,and resulting CO concentrations for four different ventilation control strategies in a model underground parking garage under a variety of assumptions for model *** four ventilation control strategies evaluated include one simplistic schedule(i.e.,Always-On)and three demand-based strategies in which fan speed is a function of CO concentrations in the spaces,including Linear-Demand Control Ventilation(DCV),Standardized Variable Flow(SVF),and a simple On-Off *** estimated annual average fan energy consumption was consistently lowest with the Linear-DCV strategy,resulting in average(±standard deviation)energy savings across all modeled scenarios of 84.3%±0.4%,72.8%±3.6%,and 97.9%±0.1%compared to SVF,On-Off,and Always-On strategies,*** utility of the framework described herein is that it can be used to model energy and indoor air quality impacts of other parking garage configurations and control scenarios.

关键词： carbon monoxide demand control ventilation energy efficiency indoor air quality underground parking garage

Noise-enhanced dynamic single leg balance in subjects with functional ankle instability

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Sport and Health Science 2012年第2期1卷 102-106页

作者： Scott Ross brent Arnold Virginia Commonwealth University

Background:Stochastic resonance stimulation(SRS) transmits subsensory electrical Gaussian white noise into the body to enhance sensorimotor *** therapy has improved static single leg balance in subjects with functional ankle ***,the effect of this stimulation on dynamic single leg balance is not *** in dynamic single leg balance with SRS may have implications For enhancing functional rehabilitation for ankle ***,the purpose of this study was to determine the effects of SRS on dynamic single leg balance in subjects with functional ankle instability. Methods:This study was an experimental research design and data were collected in a sports medicine research *** subjects with functional ankle instability(69±15 kg;173±10 cm;21±2 years) reported a history of ankle sprains and instability at the ankle with physical activity.A single leg jump-landing test was used to assess dynamic *** were required to jump between 50% and 55% of the maximal vertical jump height,land on a single leg atop a force plate,and stabilize as quickly as ***-landing tests were performed with and without *** trials were performed for each treatment condition(SRS and control).A randomized block design was used to determine test ***/posterior and medial/lateral time-to-stabilization were computed to assess dynamic *** time indicated better ***-tailed paired samples t tests were used for analysis(α≤0.05). Results:SRS improved anterior/posterior time-to-stabilization(stochastic resonance = 1.32±0.31 s,control = 1.74±0.80 s,p = 0.03),but did not enhance medial/lateral time-to-stabilization(stochastic resonance = 1.95±0.40 s,control = 1.92±0.48 s,p = 0.07). Conclusion:Clinicians might use SRS to facilitate balance improvements with sagittal plane dynamic single leg balance exercises that patients may not be able to perform otherwise.

关键词： Chronic Posture Sprain Stochastic resonance

Defect detection in freight railcar tapered-roller bearings using vibration techniques

在线全文

学校读者我要写书评

暂无评论

Railway Engineering Science 2021年第1期29卷 42-58页

作者： Constantine Tarawneh Joseph Montalvo brent Wilson University Transportation Center for Railway Safety(UTCRS) University of Texas Rio Grande Valley(UTRGV)EdinburgTXUSA Hum Industrial Technology IncSt.LouisMOUSA

Currently,there are two types of defect detection systems used to monitor the health of freight railcar bearings in service:wayside hot-box detection systems and trackside acoustic detection *** systems have proven to be inefficient in accurately determining bearing health,especially in the early stages of defect *** that end,a prototype onboard bearing condition monitoring system has been developed and validated through extensive laboratory testing and a designated field test in 2015 at the Transportation Technology Center,*** Pueblo,*** devised system can accurately and reliably characterize the health of bearings based on developed vibration thresholds and can identify defective taperedroller bearing components with defect areas smaller than 12.9 cm2 while in service.

关键词： Railcar health monitoring Onboard condition monitoring systems Bearing defect detection Bearing vibration signatures Bearing spectral analysis

Effect of saline water ionic strength on phosphorus recovery from synthetic swine wastewater

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2022年第3期34卷 81-91页

作者： Zhipeng Zhang Bing Li Filicia Wicaksana Wei Yu brent Young Department of Chemical&Materials Engineering University of AucklandAuckland 1010New Zealand

Declining worldwide phosphate rock reserves has driven a growing interest in exploration of alternative phosphate supplies. This study involved phosphorus recovery from swine wastewater through precipitation of struvite, a valuable slow-release fertiliser. The economic feasibility of this process is highly dependent on the cost of magnesium source. Two different magnesium sources were used for phosphorus recovery: pure magnesium chloride and nanofiltration(NF) saline water retentate. The paper focuses on the impact of ionic strength on phosphorus recovery performance that has not been reported elsewhere. Experimental design with five numerical variables(Mg/P molar ratio, pH, PO_(4)^(3-)-P, NH_(4)^(+)-N, and Ca^(2+) levels) and one categorical variable(type of magnesium source) was used to evaluate the effect of ionic strength on phosphorus removal and struvite purity. The experimental data were analysed using analysis of variance(ANOVA) and principal component analysis(PCA). Results indicated that a magnesium source obtained from NF retentate was as effective as MgCl_(2) for struvite precipitation. It was also revealed that ionic strength had a more positive effect on struvite purity than on phosphorus removal. Within the range of parameters studied in this research, high ionic strength, high p H and wastewater with high phosphate, high ammonium and low calcium contents were found to be the most favourable conditions for struvite precipitation. Findings from this study will be beneficial to determine the feasibility of using high ionic strength saline water, such as NF seawater retentate, as a magnesium source for phosphorus recovery from wastewater that is rich in ammoniumnitrogen and phosphate.

关键词： Phosphorus recovery Struvite Ionic strength Wastewater Nanofiltration retentate

An unexpected cause of acute liver failure

在线全文

学校读者我要写书评

暂无评论

Gastroenterology Report 2014年第3期2卷 239-241页

作者： brent Lacey Department of Gastroenterology Naval Medical Center San DiegoUSA

A 66-year-old man presented with decompensated acute liver failure with no clear ***,a bone marrow biopsy revealed hemophagocytic cells,and he was diagnosed with hemophagocytic *** is an uncommon condition in adults,with high morbidity and mortality,and it is often indistinguishable from other forms of acute liver *** clinical suspicion is critical to making the diagnosis,based on meeting at least four of nine specified criteria.

关键词： acute liver failure hemophagocytic lymphohistiocytosis

Tranexamic acid for major trauma patients in Ireland

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Emergency Medicine 2022年第1期13卷 11-17页

作者： Kieran Walsh Francis O’Keeff e Louise brent Biswadev Mitra National Trauma Research Institute the Alfred HospitalMelbourne 3004Australia Critical Care Research School of Public Health and Preventive MedicineMonash UniversityMelbourne 3004Australia Emergency&Trauma Centre Alfred HealthMelbourne 3004Australia Emergency Department Mater Misericordiae University HospitalDublin D07 R2WYIreland National Offi ce for Clinical Audit Ardilaun HouseDublin D02 VN51Ireland

BACKGROUND:The Clinical Randomisation of an Anti-fibrinolytic in Significant Hemorrhage-2(CRASH-2)is the largest randomized control trial(RCT)examining circulatory resuscitation for trauma patients to date and concluded a statistically significant reduction in all-cause mortality in patients administered tranexamic acid(TXA)within 3 hours of *** the publication of CRASH-2,significant geographical variance in the use of TXA for trauma patients *** study aims to assess TXA use for major trauma patients with hemorrhagic shock in Ireland after the publication of ***:A retrospective cohort study was conducted using data derived from the Trauma Audit and Research Network(TARN).All injured patients in Ireland between January 2013 and December 2018 who had evidence of hemorrhagic shock on presentation(as defined by systolic blood pressure[SBP]1(70.68%vs.57.43%)and higher Injury Severity Score(ISS>25;49.62%vs.23.76%).Administration of TXA was not associated with mortality at hospital discharge(odds ratio[OR]0.86,95%CI 0.31–2.38).CONCLUSIONS:Among injured Irish patients presenting with hemorrhagic shock,TXA was administered to 56.8%of *** administered with TXA were on average more severely ***,a mortality benefit could not be demonstrated.

关键词： Tranexamic acid Shock Ireland Hemorrhage

MEASURING UP: A CASE FOR REDRAWING THE SYSTEM BOUNDARIES OF SUSTAINABILITY AT THE UNIVERSITY OF KENTUCKY

在线全文

学校读者我要写书评

暂无评论

Journal of Green Building 2019年第3期14卷 161-178页

作者： brent Sturlaugson Rebekah Radtke Anita Lee-Post School of Architecture University of KentuckyLexingtonKentucky40506United States School of Interiors University of KentuckyLexingtonKentucky40506United States Gatton College of Business and Economics University of KentuckyLexingtonKentucky40506United States

The primary goal of this paper is to examine the role that sustainability assessment and reporting plays in creating a sustainable campus for academic excellence. A prototype sustainability assessment and reporting system is developed for triple bottom line impact analysis of the built environment of the newly expanded and renovated Gatton College of Business and Economics at the University of Kentucky. The prototype system utilizes a toolkit to collect environmental, social, and economic data of the building’s built environment for sustainable design performance analyses. The system also employs a comprehensive set of sustainability metrics to measure and report the building’s triple bottom line impacts on academic success. In sum, our study succeeds in (1) expanding the definition and evaluation of campus buildings’ sustainability to include environmental, social, and economic factors, (2) providing campus stakeholders with a toolkit for assessing the sustainability of campus buildings, and (3) creating a comprehensive sustainability metric for benchmarking and tracking campus buildings’ triple bottom line impacts on academic success.

关键词： sustainable campus sustainability assessment and reporting sustainability metric triple bottom line impacts academic success

Global patterns and ecological drivers of taxonomic and phylogenetic endemism in angiosperm genera

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Plant Diversity 2024年第2期46卷 149-157页

作者： Hong Qian brent D.Mishler Jian Zhang Shenhua Qian Research and Collections Center Illinois State Museum1011 East Ash StreetSpringfieldIL 62703USA University and Jepson Herbaria Department of Integrative BiologyUniversity of CaliforniaBerkeleyCA 94720-2465USA Center for Global Change and Complex Ecosystems Zhejiang Tiantong Forest Ecosystem National Observation and Research StationSchool of Ecological and Environmental SciencesEast China Normal UniversityShanghai 200241China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092China Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment Ministry of EducationChongqing UniversityChongqing 400045China

Endemism of lineages lies at the core of understanding variation in community composition among geographic regions because it reflects how speciation,extinction,and dispersal have influenced current ***,we investigated geographic patterns and ecological drivers of taxonomic and phylogenetic endemism of angiosperm genera across the *** identify centers of paleo-endemism and neo-endemism of angiosperm genera,and show that they are mostly located in the Southern Hemisphere in tropical and subtropical regions,particularly in Asia and *** categories of phylogenetic endemism centers can be differentiated using current climate *** climate,historical climate change,and geographic variables together explained~80%of global variation in taxonomic and phylogenetic endemism,while 42-46%,1%,and 15%were independently explained by these three types of variables,*** our findings show that past climate change,current climate,and geography act together in shaping endemism,which are consistent with the findings of previous studies that higher temperature and topographic heterogeneity promote *** study showed that many centers of phylogenetic endemism of angiosperms,including regions in Amazonia,Venezuela,and west-central tropical Africa that have not previously been identified as biodiversity hotspots,are missed by taxon-based measures of endemism,indicating the importance of including evolutionary history in biodiversity assessment.

关键词： Angiosperm Current climate Endemism Historical climate change Topographic heterogeneity