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Using ground penetrating radar to assess the variability of snow water equivalent and melt in a mixed canopy forest, Northern Colorado

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Frontiers of Earth Science 2017年第3期11卷 482-495页

作者： Ryan W. webb Institute of Arctic and Alpine Research University of Colorado Boulder Boulder CO 80309-0450 USA

Snow is an important environmental variable in headwater systems that controls hydrological processes such as streamflow, groundwater recharge, and evapotran- spiration. These processes will be affected by both the amount of snow available for melt and the rate at which it melts. Snow water equivalent （SWE） and snowmelt are known to vary within complex subalpine terrain due to terrain and canopy influences. This study assesses this variability during the melt season using ground penetrating radar to survey multiple plots in northwestern Colorado near a snow telemetry （SNOTEL） station. The plots include south aspect and flat aspect slopes with open, coniferous （subalpine fir, Abies lasiocarpa and engelman spruce, Picea engelmanii）, and deciduous （aspen, popu- lous tremuooides） canopy cover. Results show the high variability for both SWE and loss of SWE during spring snowmelt in 2014. The coefficient of variation for SWE tended to increase with time during snowmelt whereas loss of SWE remained similar. Correlation lengths for SWE were between two and five meters with melt having correlation lengths between two and four meters. The SNOTEL station regularly measured higher SWE values relative to the survey plots but was able to reasonably capture the overall mean loss of SWE during melt. Ground Penetrating Radar methods can improve future investiga- tions with the advantage of non-destructive sampling and the ability to estimate depth, density, and SWE.

关键词： headwaters snowmelt snow water equiva-lent ground penetrating rdar SNOTEL

A Novel Intermediate Bus Converter Topology for Cutting Edge Data Center Applications

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Chinese Journal of Electrical Engineering 2020年第4期6卷 3-14页

作者： Samuel webb Yan-Fei Liu Department of Electrical and Computer Engineering Queen’s UniversityKingston K7L 3N6Canada

As new technologies emerge data centers and servers have established themselves as one of the largest and fastest growing consumers of *** switched capacitor converter topologies have some very attractive features,namely low reliance on magnetic components and high efficiency,several critical factors have prevented their adoption in high current data center *** family of converters proposed are novel intermediate bus converter that demonstrates the highest performance yet achieved for 48 V to 12 V conversion with up to 2.5 kW/in^(3) power density,higher than 99% peak efficiency,and 97.2% full load efficiency for 12 V/70 A *** reduction of voltage stress across the MOSFETs as well as extremely low reliance on magnetics are the key driving factors behind this high efficiency and power density,and are achieved without a sensitive resonant design or the usage of complex control technique.

关键词： DC-DC converter data centers intermediate bus architecture

Impact of lactic acid bacteria on the control of Listeria monocytogenes in ready-to-eat foods

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Food Quality and Safety 2022年第3期6卷 375-385页

作者： Laura webb Luyao Ma Xiaonan Lu Department of Food Science and Agricultural Chemistry Faculty of Agricultural and Environmental SciencesMcGill UniversitySainte-Anne de-BellevueQcCanada

Due to the increased demand for ready-to-eat(RTE)minimally processed foods,alternatives to chemical and thermal preservation methods to maintain food safety are highly demanded.A significant safety hazard in RTE food products is the growth of the foodborne pathogen Listeria monocytogenes(***).After processing,recontamination or cross-contamination of *** in RTE food products may occur and the lack of cooking can lead to an increased risk of ***,some RTE food products(*** and cured meat)can have a long processing period and shelf life,thus allowing for the growth and proliferation of *** in the food *** acid bacteria(LAB)are generally recognized as safe probiotics and have been proposed as a biological control approach to eliminate foodborne pathogens including *** have been reported to extend the shelf life of food products and inhibit pathogen proliferation via growth competition and metabolite *** are native microflora of many RTE foods,but only certain LAB may inhibit pathogen ***,the specificity of LAB species should be employed in their use in RTE *** review will discuss the antimicrobial mechanisms of LAB against ***,selective use of LAB in food matrices,and their uses in food processing and packaging.

关键词： Ready-to-eat food products lactic acid bacteria Listeria monocytogenes food safety

On the radiogenic heat production of igneous rocks

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Geoscience Frontiers 2017年第5期8卷 919-940页

作者： D. Hasterok J. webb Department of Earth Sciences University of Adelaide North Terrace SA 5005 Australia Ramelius Resources Ltd. East Perth WA 6005 Australia

Radiogenic heat production is a physical parameter crucial to properly estimating lithospheric temperatures and properly understanding processes related to the thermal evolution of the Earth. Yet heat production is, in general, poorly constrained by direct observation because the key radiogenic elements exist in trace amounts making them difficulty image geophysically. In this study, we advance our knowledge of heat production throughout the lithosphere by analyzing chemical analyses of 108,103 igneous rocks provided by a number of geochemical databases. We produce global estimates of the average and natural range for igneous rocks using common chemical classification systems. Heat production increases as a function of increasing felsic and alkali content with similar values for analogous plutonic and volcanic rocks. The logarithm of median heat production is negatively correlated(r^2=0.98)to compositionally-based estimates of seismic velocities between 6.0 and 7.4 km s^(-1), consistent with the vast majority of igneous rock compositions. Compositional variations for continent-wide models are also well-described by a log-linear correlation between heat production and seismic velocity. However, there are differences between the log-linear models for North America and Australia, that are consistent with interpretations from previous studies that suggest above average heat production across much of Australia. Similar log-linear models also perform well within individual geological provinces with^1000 samples. This correlation raises the prospect that this empirical method can be used to estimate average heat production and natural variance both laterally and vertically throughout the lithosphere. This correlative relationship occurs despite a direct causal relationship between these two parameters but probably arises from the process of differentiation through melting and crystallization.

关键词： Heat generation lgneous rocks Heat producing elements Continental lithosphere Seismic velocity Density

Flood Resilience Building in Thailand: Assessing Progress and the Effect of Leadership

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International Journal of Disaster Risk Science 2018年第1期9卷 44-54页

作者： Somporn Khunwishit Chanisada Choosuk Gary webb Faculty of Management Sciences Prince of Songkla University Faculty of Environmental Management Prince of Songkla University Emergency Management and Disaster Science (EMDS)Department College of Health and Public Service University of North Texas

Disaster risk reduction has become a global strategy for making cities more resilient since the establishment of the Hyogo Framework for Action in 2005. The question that still challenges emergency management scholars and professionals, however, is what contributes to the progress of resilience building. Previous literature suggests that disaster resilience can be attributable to multiple factors, including leadership. But the specific abilities that help leaders promote resilience have not yet been examined empirically. To address this problem, using the United Nations International Strategy for Disaster Reduction 10 Essentials for Making Cities Resilient as guidelines, we assessed the progress of flood resilience building in Thailand and its relationship to local government leaders' abilities. Our research showed that, since the flood disaster in 2011, municipalities in Thailand have made moderate progress in flood resilience building. The results of a multiple regression analysis revealed that disaster resilience leadership abilities have had a statistically significant, positive effect on the progress of flood resilience building. Our findings underscore the role of leadership in making cities more resilient and shed light on how local government leaders can contribute to the progress ofdisaster risk reduction. We also outline the academic implications and practical contributions of our research.

关键词： Disaster management Disaster resilience leadership Disaster risk reduction Flood resilience building Thailand

Property-guided generation of complex polymer topologies using variational autoencoders

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npj Computational Materials 2024年第1期10卷 1825-1837页

作者： Shengli Jiang Adji Bousso Dieng Michael A.webb Department of Chemical and Biological Engineering Princeton UniversityPrincetonNJUSA Vertaix Department of Computer SciencePrinceton UniversityPrincetonNJUSA

The complexity and diversity of polymer topologies,or chain architectures,present substantial challenges in predicting and engineering polymer *** machine learning is increasingly used in polymer science,applications to address architecturally complex polymers are ***,we use a generative machine learning model based on variational autoencoders and data generated from molecular dynamics simulations to design polymer topologies that exhibit target properties.

关键词： properties. variational polymer

WATER INDEPENDENCE: A PATH TAKEN

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Journal of Green Building 2012年第3期7卷 65-79页

作者： Joe webb webb Architects 3701 Kirby Drive Suite 916HoustonTX 77098

INTRODUCTION The most prevalent questions we encounter regarding green roofs are:What drove this decision?Why an intensive green roof?What are the benefits such a constructed and constrained feature can provide?What did we discover?What changed?Is there a premium?Is the green roof a true contributor to a process?These questions give rise to the underlying issue of *** is the result of individuals interacting with their environments and the processes that either promote well-being or protect them against the overwhelming influence of risk *** and water are ***,a short bit of *** experience with green roofs began in 2005 and has resulted in five buildings-ranging in size from roughly 48,500 square feet(4,506 m2)down to 5,000 square feet(465 m2)-creating an aggregate of 1.6 acres(.648 ha)of intensive green *** acre plus of green roofs is currently in various stages of permitting,initial planning,schematic design,and construction *** on our next roof is scheduled to be complete in June of *** of our green roofs are in the Houston region.

关键词： green roofs water conservation long term operating costs healthier interior environments stormwater retention water independence Living Building Challenge

Digital re-analysis of lost architecture and the particular case of Lutyens＇ Liverpool Metropolitan Cathedral

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Frontiers of Architectural Research 2016年第2期5卷 265-275页

作者： Nicholas webb Andre Brown School of Architecture University of Liverpool Liverpool L69 7ZN United Kingdom

Research and critique of unbuilt or destroyed works of architecture is traditionally carried out through the examination of surviving information such as drawings, models, photographs, biographies and monographs. The case study presented here demonstrates that this approach cannot always give a fuU-picture of the architect or designer＇s intentions, and may miss inconsistencies in the design and links to other precedents or antecedents in such schemes. Here, we employ strategic contemporary digital representation techniques to re-present and re-analyse the evidence available for a particular architectural project. We describe a systematic methodology, which shows that these techniques can challenge or enhance current understanding. The focus therefore is on the digital re-analysis process that has been devised. Sir Edwin Lutyens＇ unbuilt Liverpool Metropolitan Cathedral design, that would have delivered one of the largest cathedrals in the world, is used as a case study. The findings reveal new information about the cathedral by following structured lines of enquiry generated from the study of primary and secondary source data, as well as serendipitous results that occur as a potential by-product of the methodological process.

关键词： Unbuitt architecture Digitalcritique Forensic anatysis Digitat modetting

Annual survival and site fidelity of free-ranging white-tailed deer (Odocoileus virginianus): comparative demography before (1983- 1992) and after (1993-2005) spatial confinement

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Integrative Zoology 2014年第1期9卷 24-33页

作者： Stephen L.webb Kenneth L.GEE The Samuel Roberts Noble Foundation ArdmoreOklahoma USA

Survival and movement are important demographic variables influencing the dynamics of large herbivores with implications for management and evolution of life-history *** practices such as spatial con-finement and harvest regulation attempt to control survival and movement for the sustainability of harvested deer populations,but a paucity of long-term data exists on these management *** examined annual survival and site fidelity of free-ranging white-tailed deer(Odocoileus virginianus)over 10 years(1983-1992)to compare demographic parameters after spatial confinement(1993-2005).We used capture records(n=174;104 females,70 males),marked deer recaptures(n=42),and dead recoveries(n=68)to estimate sex-specif-ic,age-specific and time-specific *** found that annual female survival was 50%from 1983-1987 during a period of intense harvest,but increased to 93.7%after intense harvesting was *** to spa-tial confinement,annual survival of marked male deer averaged 36.7%-42.5%.After spatial confinement,annu-al survival increased on average for males(58%-99%)and females(77%-98%).Females showed high levels of site fidelity(>99%)prior to spatial confinement,whereas males showed much less site fidelity(≤4.5%for the 2 top-ranking models).During spatial confinement,the semi-impermeable fence effectively increased site fidelity of males(≥56%).These results stem from long-term study(23 years)of a large herbivore experiencing changes to life-history,resulting from changes in management that were applied to the population and aimed at altering population demographics,for sustainability of a harvestable population of deer.

关键词： conservation deer fidelity mortality Odocoileus virginianus population dynamics