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Transport of nutrients and eutrophication control by an urban runoff diversion system protecting a drinking water reservoir

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Water science and Technology: Water Supply 2008年第2期8卷 173-180页

作者： Tran, M.L. Bahng, J. Pankratz, S.L. Suffet, I.H.M. Department of Environmental Health Sciences School of Public Health University of California Los Angeles Charles E. Young Drive South Los Angeles CA 90095 United States Environmental Science and Engineering Program School of Public Health University of California Los Angeles Charles E. Young Drive South Los Angeles CA 90095 United States

ISBN: (纸本)9781843391883

Urban runoff from five storms during the 2003-2004 and 2004-2005 rainy seasons was sampled at the exit point of runoff diversion forebays leading to engineered retention ponds to protect a drinking water reservoir. Samples were collected from three different drainage areas both years and were analysed for water quality parameters including total dissolved solids, electrical conductivity (EC), dissolved organic carbon, bacterial count and nutrients in the water phase. In the second year of the study, samples were also taken at the entry point into the forebays and analysed to determine if the forebays contributed to removal of analytes prior to diversion in the retention ponds. EC, which had been used as the determining factor of whether runoff is used to recharge or diverted to holding ponds, did not relate to nutrient levels. This indicated that EC is insufficient to determine water quality because runoff with low EC may contain high levels of nutrients that can support eutrophication. Monitoring of nutrients themselves is essential for decisions. © IWA Publishing 2008.

关键词： Nutrients

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Tracer simulation to analyze channel effect on particle transport in the Chesapeake Estuary

Tracer simulation to analyze channel effect on particle tran...

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10th International Conference on Estuarine and Coastal Modeling

作者： Wang, Ping Linker, Lewis Batiuk, Richard Lung, Wu-Seng University of Maryland Center for Environmental Science Chesapeake Bay Office 410 Severn Avenue Annapolis MD 21403 United States Chesapeake Bay Program 410 Severn Avenue Annapolis MD 21403 United States University of Virginia Dept of Civil and Environmental Engineering Charlottesville VA 22904 United States

ISBN: (纸本)9780784409909

A particulate tracer was simulated by the Chesapeake Bay Estuarine Model. The tracer was loaded daily at the fall-line of Potomac River (a middle Bay's tributary), with a settling rate at 0.1 m/day. After tracers reached the mouth of Potomac River, most of them were transported to the lower-Bay. The landward movement with saline water intrusion is the main force for tracer transport to the upper-Bay and the upstream of non-source rivers. In the main-stem Bay, there exist concentration gradients from the Potomac mouth to the opposite shore, to the lower-Bay, and to the upper-Bay. These gradients are disturbed across deep channels. The landward saline water is favored along the deep channel over their shallower sides. Depending on the layer (saline or fresh water) that the tracer resides in and the direction that the tracer is transported, the preferential in tracer transport/deposit along channel versus its shallower sides is different. Contrasting "channel effects" are observed between the source river and non-source rivers, and between the lower Bay and the upper upper-Bay. Generally, the channel at the source-river or down-Bay have less tracer than the shallower sides;whereas, the channels at non-source rivers or the up Bay have more tracer than the shallower sides. The phenomena of the channel effect are disturbed by local bathymetry and freshwater inputs. The tracer simulation shows how particles are transported by the estuarine circulation, providing information for strategic source controls to protect targeted waterways. © 2008 American Society of Civil Engineers.

关键词： Rivers

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Nonmetallic inclusions in solar cell silicon: Focusing on recycling of scraps

Nonmetallic inclusions in solar cell silicon: Focusing on re...

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2008 Global Symposium on Recycling, Waste Treatment and Clean Technology, REWAS 2008

作者： Zhang, Lifeng Øvrelid, Eivind Senanu, Samuel Agyei-Tuffour, Benjamin Femi, Adegboyega Nathaniel Department of Materials Sci. and Engr. Missouri University of Science and Technology 223 McNutt Hall Rolla MO 65401 United States SINTEF Tronheim Norway Department of Materials Science and Engineering Norwegian University of Science and Technology Norway Department of Environmental Program University of Northern Iowa Cedar Falls IA 50614 United States

ISBN: (纸本)9780873397261

The solar grade silicon ingot produced from directional solidification process usually pushes the impurities to the top and finally cut off and discarded, which leads to material loss. The hard inclusions lead to wire breakages during the cutting of the ingot in wafers. The main kinds of inclusions found in solar grade silicon have been investigated using vacuum filtration: needle-like Si3N4 and lumpy SiC inclusions. Clusters of SiC inclusions and Si3N4 are also found. Surface observations of the scraps before polishing reveals that Si 3N4 inclusions are usually bigger and in some cases can be about a few millimeters. SiC inclusions are usually smaller, ∼200m but can be ∼500m in some cases. Inclusions observed after filtration are mainly SiC with diameters ∼10m. Through the vacuum filtration, 99% inclusions can be removed 99%. The possible mechanisms of filtration are cake filtration for the larger sized Si3N4 and SiC inclusions and deep-bed filtration the SiC inclusions. For the directional solidified silicon ingot, an approximate distance of ∼10mm gave an encouraging cutoff thickness. The inclusions sizes were below 10m.

关键词： Silicon carbide

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MERCURY CYCLING THROUGH A TIDAL CYCLE USING DATA FROM AN EMBEDDED SENSOR NETWORK:A COMPARISON BETWEEN TWO ESTUARINE HABITATS

MERCURY CYCLING THROUGH A TIDAL CYCLE USING DATA FROM AN EMB...

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10th International Estuarine Biogeochemistry Symposium(第十届河口生物地球化学国际研讨会)

作者： Sarah Rothenberg Nithya Ramanathan Deborah Estrin Jennifer Jay State Key Laboratory of Environmental Geochemistry GuiyangChina Department of Computer ScienceUniversity of CaliforniaLos AngelesUSA Department of Civil and Environmental EngineeringUniversity of CaliforniaLos AngelesUSA Environmental Science and Engineering Program University of CalifomiaLos AngelesUSA

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Controlling taste and odour events for the city of Philadelphia, USA: A case study

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Water science and Technology: Water Supply 2008年第2期8卷 135-141页

作者： Suffet, I.H. Mel Burlingame, Gary Mackey, Erin Environmental Science and Engineering Program-UCLA School of Public Health Charles E. Young Drive South Los Angeles CA 90095-1772 United States Philadelphia Water Department Bureau of Laboratory Services 1500 E. Hunting Park Avenue Philadelphia PA 19124 United States Carollo Engineers 12592 West Explorer Dr. Boise ID 83713 United States

ISBN: (纸本)9781843391883

The overall goal of this case study is to describe the history and present methods that the Philadelphia Water Department (PWD) uses to address its on-going earthy and musty drinking water T&O problems. The Philadelphia Water Department has developed a baseline for its water's aesthetic qualities since the early 1980's. Philadelphia feels it has sufficient resources to control taste and odour problems. However, when directly asked, only 61-64% of the consumers are satisfied with the taste and odour of Philadelphia's drinking waters. A taste and odour early warning system is being developed for the two drinking water sources, the Delaware and Schuylkill rivers. Secondly, routine T&O panels and chemical analysis of geosmin and MIB are completed. Since the year 2000, 10 ng/L has become an early warning wake-up call for PWD. When higher levels are observed, testing is a priority, the source of the T&O is investigated and consumer complaints are monitored carefully. Present water treatment plants are conventional with chlorine disinfection, coagulation/sedimentation, rapid dual media filtration and final chloramination. The PWD uses powdered activated carbon, river water bypass and hydraulic changes in the distribution system to minimise odour events. © IWA Publishing 2008.

关键词： Potable water

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Site specific farming, environmental concerns, and associated advanced technologies, provide a platform for active learning and research at a land grant university

Site specific farming, environmental concerns, and associate...

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2008 ASEE Annual Conference and Exposition

作者： Nagchaudhuri, Abhijit Mitra, Madhumi Marsh, Lurline Daughtry, Craig Earle, Tracy Schwarz, Jurgen University of Maryland Eastern Shore Department of Engineering and Aviation Sciences University of Maryland Eastern Shore Department of Biology and Environmental Science University of Maryland Eastern Shore Biology Education Program UMES Department of Agriculture and Resource Sciences University of Maryland Eastern Shore United States Department of Agriculture USDA-ARS Hydrology and Remote Sensing Laboratory Beltsville MD United States Dept of Agriculture UMES Department of Agriculture and Resource Sciences Program in Food Science and Technology

A course titled "Advanced Technologies in Agriculture and environmental sciences" was offered for the first time at the University of Maryland Eastern Shore in spring of 2007. The course was conceived to develop a broader student base for the "Precision Agriculture" related activities that have been ongoing at UMES for the past few years, with support from the United States Department of Agriculture (USDA) and Maryland Space Grant Consortium (MDSGC), and as such has been opened to all science, Technology, engineering, and Mathematics (STEM) seniors and graduate students on campus. In an effort to diffuse the compartmentalization of knowledge and rigid disciplinary boundaries within academia, the course has been designed to be a multi-instructor course. Faculty and staff from Agriculture, Natural sciences, engineering, Aviation sciences, and collaborators from USDA, NASA, and representatives from a local industry involved in "Precision Farming" have worked together to plan and deliver the course. The course content spans over the fundamentals of global positioning systems (GPS), yield monitoring, soil testing, variable rate applicators, fundamentals of plant physiology and agronomy, Geographical Information Systems (GIS), statistics and data analysis, aerial imaging and remote sensing, & nutrient and watershed management. Significant field work using various field sensors, including a chlorophyll meter, pH meter, and other instrumentation to measure leaf area index (LAI) in conjunction with hand held GPS units, is integrated with the course. Funds from USDA will cover at least four summer interns who will be selected from the course participants each year, while the grant is active (2009) to continue experiential learning and research activities initiated in spring as an integral part of the course, during the summer months. © American Society for engineering Education, 2008.

关键词： Global positioning system

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Moisture Absorption Phenomena in Green Composite Printed Circuit Board Prototypes

Moisture Absorption Phenomena in Green Composite Printed Cir...

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Pulsed Power Conference, 2005 IEEE;San Francisco,CA,USA

作者： John D. Lincoln Andrew A. Shapiro Jean-Daniel M. Saphores Oladele A. Ogunseitan Department of Chemical Engineering and Materials Science University of California Irvine CA USA Department of Electrical Engineering and Computer Science University of California Irvine CA USA Departments of Civil and Environmental Engineering Economics and Planning Policy and Design University of California Irvine CA USA Public Health Program College of Health Sciences and the Program in Industrial Ecology Department of Environmental Health Science and Policy University of California Irvine CA USA

ISBN: (纸本)9781424422722

This research developed the moisture-resistance of printed circuit board (PCB) laminate prototypes based on the non-toxic composite materials made from epoxidized linseed oil, melamine polyphosphate, and flax fibers. One of the key issues associated with using renewable base materials in composites is their sensitivity to moisture. A characterization of the properties of the 'green' printed circuit boards developed in the present study showed that moisture absorption for untreated fiber laminates (4.87% vs. established limit <0.8% for FR4 boards over a 24 hour submersion period) compromised electrical resistance and decreased dielectric breakdown to an unacceptable level. A theoretical model was used to target methods for reducing moisture absorption. Based on this model, we found that reductions in fiber diffusivity and fiber volume fraction substantially reduce composite diffusivity. Through the use of chemical treatment, moisture absorption over a 24 hour time period was reduced from 4.87% to 1.15%, which improved electrical properties. At the end of this study, 15 of 18 PCB property requirements were met, while 3 moisture-critical property targets were narrowly missed.

关键词： Printed Circuit Board Design for Environment Green Composite Moisture Absorption Natural Fiber

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Polysulfone-silver nanocomposites for membrane biofouling mitigation: Formation-structure-function relationships

Polysulfone-silver nanocomposites for membrane biofouling mi...

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American Water Works Association Association Annual Conference and Exposition, ACE 2008

作者： Taurozzi, Julian S. Arul, Hari Bosak, Volodymyr Z. Burban, Anatoliy F. Voice, Thomas C. Bruening, Merlin L. Tarabara, Volodymyr V. Department of Civil and Environmental Engineering Michigan State University East Lansing MI 48824 United States High School Honors Science Mathematics Engineering Program Michigan State University United States Department of Chemistry National University of Kyiv-Mohyla Academy 2 Skovoroda St. Kyiv 04070 Ukraine Department of Chemistry Michigan State University United States

ISBN: (纸本)9781605607801

• Ex-situ and in-situ routes of filler incorporation resulted in markedly different nanocomposite morphologies. The two methods yielded differences in both the size of the silver filler and its distribution along the cross-section of the polymer matrix. • The nanocomposites showed evident biocidal effect, which was affected by the distribution of silver within the polymeric matrix (in vs ex-situ, types I, II, III), while its biofouling effectiveness was dependant on flow configuration (downstream vs upstream release) • The nanocomposites can be potentially used as upstream controlled release flow through devices (spacers) for biofouling mitigation • The reduction of ionic silver by polymer solvents prior to or during the phase inversion process can be employed to synthesize biocidal silver-polymer nanocomposites of a range of porosities and nano-scale silver distributions. © 2008 American Water Works Association.

关键词： Fillers

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Safety management on fire emergency response by VESDA applications at semiconductor plants

Safety management on fire emergency response by VESDA applic...

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IEEE International Conference on Systems, Man and Cybernetics

作者： Chun-Ping Lin Chi-Min Shu Doctoral Program Graduate School of Engineering Science and Technology National Yunlin University of Science and Technology Yunlin Taiwan Process Safety and Disaster Prevention Laboratory Department of Safety Health and Environmental Engineering National Yunlin University of Science and Technology Yunlin Taiwan

To take an advantageous stance in the recent competition of semiconductor industries, companies have made efforts to invest terms of technological advancements. From 1993 to 2006, enormous fire accidents occurred in three national science parks in Taiwan. This research focused on whether the very early smoke detection apparatus (VESDA), could adequately assist the emergency response center (ERC) members to take actions when alarm occurs. Besides, the research also analyzed every VESDA alarm that happened from 2004 to 2006 for the purpose of increasing ERC personnel's experience and coordinating ERC with departments of safety management, environmental protection, facility engineering, and equipment sections together to investigate better solutions to related problems.

关键词： Disaster management Fires Electronics industry Accidents Smoke detectors Personnel Safety devices environmental management engineering management Protection

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Thermophysical Properties of PuO2 and AmO2 Solid Solutions Simulated by Molecular Dynamics

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MRS Online Proceedings Library 2008年第1期1043卷 1-6页

作者： Tosawat Seetawan Thaweewat Khuangthip Vittaya Amornkitbamrung Ken Kurosaki Jun Adachi Masahito Katayama Anek Charoenphakdee Shinsuke Yamanaka Program of Physics Faculty of Science and Technology Sakon Nakhon Rajabhat University Sakon Thailand Integrated Nanotechnology Research Center and Departments of Physics Khon Kaen Thailand Division of Sustainable Energy and Environmental Engineering Graduate School of Osaka University Suita Japan

PuO2 and AmO2 solid solutions: (Pu, Am)O2 are one of the candidates of fuels in a sub-critical accelerator-driven system (ADS). To understand the fuel performance, the thermophysical properties such as thermal conductivity and heat capacity are quite important. However, it is very hard to experimentally determine the physical properties of plutonium as well as americium compounds due to their handling-difficulties. Molecular dynamics (MD) would be a specific method to describe the physical properties of such materials. In the present study, we have investigated thermophysical properties of PuO2, AmO2, and their solid solutions in the temperature range from 300 to 2,500 K. The lattice parameter, compressibility, heat capacity, linear thermal expansion coefficient, and thermal conductivity were evaluated. A Morse-type potential function added to the Busing-Ida type potential was employed as the potential for interatomic interactions. The calculated lattice parameters of (Pu, Am)O2 obeyed Vegard’s law, and the values increased with temperature. The heat capacities of (Pu, Am)O2 were similar in any compositions. The thermal conductivities of (Pu, Am)O2 were lower than those of PuO2 and AmO2, indicating that a point-defect scattering effect of phonons could be realized in the MD calculations.

关键词： composite oxide microstructure

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