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2012

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Articles 91 - 120 of 171

Full-Text Articles in Engineering

The Water Footprint Of Humanity, Arjen Y. Hoekstra, Mesfin Mekonnen Feb 2012

The Water Footprint Of Humanity, Arjen Y. Hoekstra, Mesfin Mekonnen

Daugherty Water for Food Global Institute: Faculty Publications

This study quantifies and maps the water footprint (WF) of humanity at a high spatial resolution. It reports on consumptive use of rainwater (green WF) and ground and surface water (blue WF) and volumes of water polluted (gray WF). Water footprints are estimated per nation from both a production and consumption perspective. International virtual water flows are estimated based on trade in agricultural and industrial commodities. The global annual average WF in the period 1996–2005 was 9,087 Gm3 ∕y (74% green, 11% blue, 15% gray). Agricultural production contributes 92%. About one-fifth of the global WF relates to production for export. …


Impacts Of Changes In Land Use And Land Cover On Atmospheric Chemistry And Air Quality Over The 21st Century, S. Wu, L. J. Mickley, J. O. Kaplan, D. J. Jacob Feb 2012

Impacts Of Changes In Land Use And Land Cover On Atmospheric Chemistry And Air Quality Over The 21st Century, S. Wu, L. J. Mickley, J. O. Kaplan, D. J. Jacob

Michigan Tech Publications, Part 1

The effects of future land use and land cover change on the chemical composition of the atmosphere and air quality are largely unknown. To investigate the potential effects associated with future changes in vegetation driven by atmospheric CO 2 concentrations, climate, and anthropogenic land use over the 21st century, we performed a series of model experiments combining a general circulation model with a dynamic global vegetation model and an atmospheric chemical-transport model. Our results indicate that climate-and CO 2-induced changes in vegetation composition and density between 2100 and 2000 could lead to decreases in summer afternoon surface ozone of up …


Selective Fluoride Removal By Aluminum Precipitation & Membrane Filtration, Emily Kowalchuk Feb 2012

Selective Fluoride Removal By Aluminum Precipitation & Membrane Filtration, Emily Kowalchuk

Civil Engineering ETDs

Fluoride is an anionic constituent of most natural surface and ground waters. At low concentrations it has the beneficial effect of improving dental health, but at high concentrations it causes skeletal and other problems. The drinking water standard for fluoride is 4.0 mg/L, but even at this level approximately 10% of exposed children will develop dental enamel fluorosis. Several small communities in New Mexico have source waters with fluoride concentrations higher than 4.0 mg/L. No commercial technologies selectively remove fluoride from drinking water in part because it is relatively non-reactive in aqueous solution and also because its chemistry is similar …


Heat Transfer Coefficients In Mimicked Fischer-Tropsch Slurry Bubble Columns, Chengtian Wu, Muthanna H. Al-Dahhan Feb 2012

Heat Transfer Coefficients In Mimicked Fischer-Tropsch Slurry Bubble Columns, Chengtian Wu, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

To Provide More Support for Fischer-Tropsch (FT) Slurry Bubble Column Reactor Design, Scale-Up, and Performance, the Effects of Operating Conditions on the Heat Transfer Coefficients Were Investigated in a Mimicked FT Cold Flow System (Compressed Air:C 9-C 11:FT Catalyst Carrier). the Studied Operating Conditions Varied in Superficial Gas Velocity (Up to 0.3 M/s), Pressure (Up to 10 Bar), and Solids Concentration (Up to 25 Vol %). the Effects of These Variables on Heat Transfer Coefficients Are Discussed and Analyzed. the Increase in Pressure Tended to Reduce the Heat Transfer Coefficient, While the Increase in Solids Loading Enhanced the Heat Transfer …


The Bridge Newsletter Spring 2012, Missouri University Of Science And Technology Feb 2012

The Bridge Newsletter Spring 2012, Missouri University Of Science And Technology

The Bridge Newsletter

-Light-weight foam could cushion expensive bridge repairs
-New Chancellor
-The house of the future today
-High-tech approach to project management


Trust Management Schemes For Peer-To-Peer Networks, Lin Cai Jan 2012

Trust Management Schemes For Peer-To-Peer Networks, Lin Cai

Dissertations

Peer-to-peer (P2P) networking enables users with similar interests to exchange, or obtain files. This network model has been proven popular to exchange music, pictures, or software applications. These files are saved, and most likely executed, at the downloading host. At the expense of this mechanism, worms, viruses, and malware find an open front door to the downloading host and gives them a convenient environment for successful proliferation throughout the network. Although virus detection software is currently available, this countermeasure works in a reactive fashion, and in most times, in an isolated manner. A trust management scheme is considered to contain …


Distributed Spectrum Leasing Via Cooperation, Tariq Elkourdi Jan 2012

Distributed Spectrum Leasing Via Cooperation, Tariq Elkourdi

Dissertations

“Cognitive radio” networks enable the coexistence of primary (licensed) and secondary (unlicensed) terminals. Conventional frameworks, namely commons and property-rights models, while being promising in certain aspects, appear to have significant drawbacks for implementation of large-scale distributed cognitive radio networks, due to the technological and theoretical limits on the ability of secondary activity to perform effective spectrum sensing and on the stringent constraints on protocols and architectures.

To address the problems highlighted above, the framework of distributed spectrum leasing via cross-layer cooperation (DiSC) has been recently proposed as a basic mechanism to guide the design of decentralized cognitive radio networks. According …


The Nucleus 2011-2012, Rosalie A. Richards Jan 2012

The Nucleus 2011-2012, Rosalie A. Richards

Science Education Center

No abstract provided.


Numerical Analysis Of Concrete-Filled Circular Steel Tubes, Yaohua Deng, Terri R. Norton, Christopher Y. Tuan Jan 2012

Numerical Analysis Of Concrete-Filled Circular Steel Tubes, Yaohua Deng, Terri R. Norton, Christopher Y. Tuan

Civil Engineering Faculty Publications

Concrete-filled steel tubes have been widely used in building and bridge construction. In this paper, the flexural behaviour of concrete-filled steel tubes is investigated using finite-element analysis and theoretical sectional analysis. The numerical results from both analytical methods are validated against published experimental test results. It is shown that both methods are capable of predicting the elastic and the ultimate moment capacities of concrete-filled steel tubes. Due to its computational efficiency, theoretical sectional analysis is more suitable for the design of concrete-filled steel tubes than finite-element analysis.


The Potential Of Industrial Waste And Agricultural Feedstock Towards Sustainable Biofuels Production: Techno-Economic And Environmental Impact Perspectives, Felix K. Adom Jan 2012

The Potential Of Industrial Waste And Agricultural Feedstock Towards Sustainable Biofuels Production: Techno-Economic And Environmental Impact Perspectives, Felix K. Adom

Dissertations, Master's Theses and Master's Reports - Open

This Ph.D. research is comprised of three major components; (i) Characterization study to analyze the composition of defatted corn syrup (DCS) from a dry corn mill facility (ii) Hydrolysis experiments to optimize the production of fermentable sugars and amino acid platform using DCS and (iii) Sustainability analyses. Analyses of DCS included total solids, ash content, total protein, amino acids, inorganic elements, starch, total carbohydrates, lignin, organic acids, glycerol, and presence of functional groups. Total solids content was 37.4% (± 0.4%) by weight, and the mass balance closure was 101%. Total carbohydrates [27% (± 5%) wt.] comprised of starch (5.6%), soluble …


Engineering Research 2012, College Of Engineering, Michigan Technological University Jan 2012

Engineering Research 2012, College Of Engineering, Michigan Technological University

Michigan Tech Engineering Magazine

Table of Contents

  • Energy
  • Engineered Materials
  • Health
  • Education & Outreach
  • Earth & Water
  • People


What Are The Characteristics Of A Scholar?, Andreas Tolk Jan 2012

What Are The Characteristics Of A Scholar?, Andreas Tolk

Computational Modeling & Simulation Engineering Faculty Publications

No abstract provided.


Impact Of 2000-2050 Climate Change On Global Atmospheric Transport And Deposition Of Mercury, Wenchao Chen Jan 2012

Impact Of 2000-2050 Climate Change On Global Atmospheric Transport And Deposition Of Mercury, Wenchao Chen

Dissertations, Master's Theses and Master's Reports - Open

Since it is very toxic and accumulates in organisms, particularly in fish, mercury is a very important pollutant and one of the most studies. And this concern over the toxicity and human health risks of mercury has prompted efforts to regulate anthropogenic emissions. As mercury pollution problem is getting increasingly serious, we are curious about how serious this problem will be in the future. What is more, how the climate change in the future will affect the mercury concentration in the atmosphere. So we investigate the impact of climate change on mercury concentration in the atmosphere. We focus on the …


Santa Clara Magazine, Volume 53 Number 3, Winter 2012, Santa Clara University Jan 2012

Santa Clara Magazine, Volume 53 Number 3, Winter 2012, Santa Clara University

Santa Clara Magazine

18 - MY FIGHT, MY FAITH By Steven Boyd Saum. As head of the CIA, Leon Panetta '60, J.D. '63 restored confidence in the agency and oversaw the mission to find Osama bin Laden. Now, as secretary of defense in an age of budget austerity, he has to make sure the Pentagon doesn't break the bank-and that the nation doesn't break faith with the men and women who serve.

24 - GENERAL JOE By Sam Scott '96. When Joseph Peterson '72 signed up for ROTC as an undergrad, he planned to complete his military service and then move on. Nearly …


Network-Based Data Collection For A Project-Based Freshman Class, Samuel Bogan Daniels, Cheryl Q. Li, David Harding Jan 2012

Network-Based Data Collection For A Project-Based Freshman Class, Samuel Bogan Daniels, Cheryl Q. Li, David Harding

Mechanical and Industrial Engineering Faculty Publications

The hands-on experience for engineering students is often lacking with class sizes increasing and classroom resources under constant pressure. Even with smaller class sizes and studio classrooms there is only so much equipment and technical support to run experiments and allow for student interaction. Network-based data collection and control may alleviate some of these issues and allow for more hands-on experiences, although remote, in the classroom. This paper discusses the interesting problems and not so obvious pitfalls of setting up some simple network-based data acquisition systems for a multidisciplinary freshman level engineering course. The course as currently taught includes some …


Santa Clara Magazine, Volume 54 Number 2, Fall 2012, Santa Clara University Jan 2012

Santa Clara Magazine, Volume 54 Number 2, Fall 2012, Santa Clara University

Santa Clara Magazine

18 - WE, ROBOTS By John Deever. Adventures with the Robotics Systems Laboratory by land, sea, and sky. And in orbit.

20 - SARAH KATE WILSON VS. GODZILLA By Jeff Gire. Tackling big problems- like attracting more women to engineering and transferring mountains of data through the air.

22 - DELUGE AND DROUGHT By Erica Klarreich. Lessons in how to wedge more data into less space-and build a smarter energy grid.

24 - BUILDING BIOMEDICAL TESTS By Melissae Fellet. Where engineering meets biology, the work ranges from diagnosing voice disorders to tracking toxicity in the brain.

26 - THE LONG …


Santa Clara Magazine, Volume 53 Number 4, Spring 2012, Santa Clara University Jan 2012

Santa Clara Magazine, Volume 53 Number 4, Spring 2012, Santa Clara University

Santa Clara Magazine

20 - WHAT WILL YOU BE? By David Mckay Wilson. San Francisco's Immaculate Conception Academy has found a work-study program that gives low-income students what they need. Starting with a bigger view of the world.

22 - BUCKY BRONCO CONFIDENTIAL By Jeff Gire And Sam Scott '96. Who wears the costume today may be classified information. But here are a few secrets revealed-including how Bucky came to be.

26 - TALKIN' DUST BOWL BLUES By David Mckay Wilson. The ghost of Woody Guthrie stalks the stage-with Rob Tepper '00 playing the role. This year marks the centennial of the iconic …


The Effect Of Clusters Within Crowds Of Pedestrians On The Vertical Response Of A Flexible Footbridge, Joe Keogh, Colin C. Caprani, Paul Archbold, Paul Fanning Jan 2012

The Effect Of Clusters Within Crowds Of Pedestrians On The Vertical Response Of A Flexible Footbridge, Joe Keogh, Colin C. Caprani, Paul Archbold, Paul Fanning

Conference papers

The issue of excessive vibrations of footbridges due to the passage of pedestrians has been well documented in the past decade. Despite this there still remains great uncertainty as to how to predict the acceleration response of a footbridge due to crowd loading. This paper investigates the vibration response of a flexible footbridge subjected to crowd loading. Using a statistical model which caters for the variability of pedestrians, the vibration response of the footbridge is obtained. In this work, the effect of social groups or clusters of pedestrians in a crowd is investigated. Herein a cluster is defined as two …


Biofuels Production From Hydrotreating Of Vegetable Oil Using Supported Noble Metals, And Transition Metal Carbide And Nitride, Huali Wang Jan 2012

Biofuels Production From Hydrotreating Of Vegetable Oil Using Supported Noble Metals, And Transition Metal Carbide And Nitride, Huali Wang

Wayne State University Dissertations

The focus of this research is to prepare non-sulfided hydrotreating catalysts, supported noble metal and transition metal carbide/ nitride, and evaluate their hydrocracking activities and selectivities by using soybean oil as the feedstock. For comparison study, catalytic cracking of soybean oil over a commercialized ZSM-5 was investigated. However, steady state could not be reached because significant amounts of tar and coke were generated during the reaction though a high yield (21%) of jet fuel was obtained from the process. Compared to the catalytic cracking process, less tar and coke were formed during the hydrocracking process and stable continuous flow reaction …


Year Eight Annual Report: Activities, Findings And Evaluators' Reports, Ncete Faculty, Jim Dorward Jan 2012

Year Eight Annual Report: Activities, Findings And Evaluators' Reports, Ncete Faculty, Jim Dorward

Reports to NSF

The National Center for Engineering and Technology Education (NCETE) is a collaborative network of scholars with backgrounds in technology education, engineering, and related fields. Our mission is to build capacity in technology education and to improve the understanding of the learning and teaching of high school students and teachers as they apply engineering design processes to technological problems. NCETE was granted a no-cost extension for an eighth year of work. Significant activities were focused in three areas: building research capacity within the engineering and technology education field; building on current research programs; and communicating and disseminating NCETE works and findings.


The Biological Systems Engineering Program In Nebraska 1895-2011, William Splinter Jan 2012

The Biological Systems Engineering Program In Nebraska 1895-2011, William Splinter

Department of Agricultural and Biological Systems Engineering: Faculty Publications

4. Preface: How Mechanization Has Impacted Food Production THE PIONEERS WHO ESTABLISHED THIS DEPARTMENT 8 Oscar Van Pelt Stout 10 Charles Russ Richards 12 J. Brownlee Davidson 14 Leon W. Chase FORMER FACULTY AND THEIR CONTRIBUTIONS 18 Laurence Froyd Seaton 20 Ivan D.Wood 22 Oscar W. Sjogren 23 Chauncey W. Smith 25 Elmer E. Brackett 27 Claud Kedzie Shedd 29 Ruby M. Loper 31 Lester F. Larsen 33 Lloyd W. Hurlbut 36 Rollin Schnieder 39 Howard D. Wittmuss 41 Deon Axthelm 46 Paul. E. Fischbach 48 Stuart O. Nelson 51 Kenneth von Bargen 56 John R. Davis 58 Robert W. …


Global Estimation Of Evapotranspiration Using A Leaf Area Index-Based Surface Energy And Water Balance Model, H. Yan, S.Q. Wang, David P. Billesbach, Walter Oechel, J.H. Zhang, Tilden Meyers, Ta. Martin, Roser Matamala, Dennis D. Baldocchi, G. Bohrer, D. Dragoni, R. Scott Jan 2012

Global Estimation Of Evapotranspiration Using A Leaf Area Index-Based Surface Energy And Water Balance Model, H. Yan, S.Q. Wang, David P. Billesbach, Walter Oechel, J.H. Zhang, Tilden Meyers, Ta. Martin, Roser Matamala, Dennis D. Baldocchi, G. Bohrer, D. Dragoni, R. Scott

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Studies of global hydrologic cycles, carbon cycles and climate change are greatly facilitated when global estimates of evapotranspiration (E) are available. We have developed an air-relative-humidity-based two-source (ARTS) E model that simulates the surface energy balance, soil water balance, and environmental constraints on E. It uses remotely sensed leaf area index (Lai) and surface meteorological data to estimate E by: 1) introducing a simple biophysical model for canopy conductance (Gc), defined as a constant maximum stomatal conductance gsmax of 12.2mm s−1multiplied by air relative humidity (Rh …


Using Microwave Brightness Temperature Diurnal Cycle To Improve Emissivity Retrievals Over Land, Hamidreza Norouzi, William Rossow, Marouane Temimi, Catherine Prigent, Marzieh Azarderakhsh, Sid Boukabara, Reza Khanbilvardi Jan 2012

Using Microwave Brightness Temperature Diurnal Cycle To Improve Emissivity Retrievals Over Land, Hamidreza Norouzi, William Rossow, Marouane Temimi, Catherine Prigent, Marzieh Azarderakhsh, Sid Boukabara, Reza Khanbilvardi

Publications and Research

To retrieve microwave land emissivity, infrared surface skin temperatures have been used as surface physical temperature since there is no global information on physical vegetation/soil temperature profiles. However, passive microwave emissions originate fromdeeper layerswith respect to the skin temperature. So, this inconsistency in sensitivity depths between skin temperatures and microwave temperaturesmay introduce a discrepancy in the determined emissivity. Previous studies showed that this inconsistency can lead to significant differences between day and night retrievals of land emissivity which can exceed 10%. This study proposes an approach to address this inconsistency and improve the retrieval of land emissivity using microwave observations …


Algorithms For Community Identification In Complex Networks, Mahadevan Vasudevan Jan 2012

Algorithms For Community Identification In Complex Networks, Mahadevan Vasudevan

Electronic Theses and Dissertations

First and foremost, I would like to extend my deepest gratitude to my advisor, Professor Narsingh Deo, for his excellent guidance and encouragement, and also for introducing me to this wonderful science of complex networks. Without his support this dissertation would not have been possible. I would also like to thank the members of my research committee, professors Charles Hughes, Ratan Guha, Mainak Chatterjee and Yue Zhao for their advice and guidance during the entire process. I am indebted to the faculty and the staff of the Department of Electrical Engineering and Computer Science for providing me the resources and …


Microstructural And Mineralogical Transformation Of Hydraulically Disposed Fly Ash—Implications To The Environment, Jabulani S. Mahlaba, Elsabe P. Kearsley, Richard A. Kruger Jan 2012

Microstructural And Mineralogical Transformation Of Hydraulically Disposed Fly Ash—Implications To The Environment, Jabulani S. Mahlaba, Elsabe P. Kearsley, Richard A. Kruger

Coal Combustion and Gasification Products Journal Archive

Increasing amounts of coal are combusted annually to meet the ever-increasing energy demands. The inevitable by-products include fly ash and saline effluents, which require acceptable disposal. The aim of this article is to compare the effect of hydraulic disposal with dry ash dumping. The results indicate that the former carries more environmental benefits based on the physical, chemical, and mineralogical aspects that were investigated.


Mineralogical Transformations In Coal Feedstocks During Carbon Conversion, Based On Packed-Bed Combustor Tests: Part 2. Behavior Of Individual Particles, Ratale H. Matjie, Colin R. Ward, Zhongsheng Li Jan 2012

Mineralogical Transformations In Coal Feedstocks During Carbon Conversion, Based On Packed-Bed Combustor Tests: Part 2. Behavior Of Individual Particles, Ratale H. Matjie, Colin R. Ward, Zhongsheng Li

Coal Combustion and Gasification Products Journal Archive

Handpicked carbon-rich particles (coal or char), mineral-rich particles (heated stones), and bonded stone aggregates (clinkers) from the upper and lower parts of a pilot-scale packed-bed combustor bed, designed to simulate conversion or combustion processes, were subjected to mineralogical and inorganic geochemical studies, in order to evaluate the reactions that may occur during carbon conversion at a particle-by-particle scale. The mineral matter of the carbon-rich particles was found to have higher proportions of carbonate minerals and kaolinite than the mineral-rich (stone) particles in the coal feedstocks used in the study, and to form phases such as anorthite, gehlenite, pyrrhotite, troilite, and …


Mineralogical Transformations In Coal Feedstocks During Carbon Conversion, Based On Packed-Bed Combustor Tests: Part 1. Bulk Coal And Ash Studies, Ratale H. Matjie, Colin R. Ward, Zhongsheng Li Jan 2012

Mineralogical Transformations In Coal Feedstocks During Carbon Conversion, Based On Packed-Bed Combustor Tests: Part 1. Bulk Coal And Ash Studies, Ratale H. Matjie, Colin R. Ward, Zhongsheng Li

Coal Combustion and Gasification Products Journal Archive

Mineralogical and inorganic geochemical studies have been carried out on composite samples of six different coarse-crushed (,120 mm) feed coals tested in a pilot-scale packed-bed combustor designed to simulate conversion and some fixed-bed combustion processes, and also on composite samples of the ashes produced. The mineral matter of the coals consisted mainly of quartz, kaolinite, and Ca-bearing carbonate minerals (calcite, dolomite, aragonite), with minor proportions of illite, pyrite, and several other phases, along with some Ca in an organically associated form. The base to acid ratio of the coal ashes ranged from 0.1 to 0.3, due mainly to variations in …


Distributed Solar Photovoltaic Grid Integration System : A Case Study For Performance, Ming Shen Jan 2012

Distributed Solar Photovoltaic Grid Integration System : A Case Study For Performance, Ming Shen

Dissertations and Theses

The needs to the sustainable development of electricity, energy efficiency improvement, and environment pollution reduction have favored the development of distributed generation (DG). But the problems come with increasing DG penetration in distribution networks. This thesis presents the Solar Energy Grid Integration System (SEGIS) Stage III project done by Portland General Electric (PGE), Advanced Energy, Sandia National Lab on a PGE selected distribution feeder. The feeder has six monitored commercial solar PV systems connected. The total power output from the PV systems has the potential to reach 30% of the feeder load. The author analyzes the performance of the solar …


Commentary And Interpretations Of Tagore’S 'Ode To Africa', Monish Ranjan Chatterjee Jan 2012

Commentary And Interpretations Of Tagore’S 'Ode To Africa', Monish Ranjan Chatterjee

Electrical and Computer Engineering Faculty Publications

This is a commentary/interpretation of Rabindranath Tagore's poem "Ode to Africa."


Development Of An Industrial Fabrication Process For Next Generation, Thinner And Larger Crystalline Silicon (C-Si) Wafer-Based Solar Cells, Anh Viet Nguyen Jan 2012

Development Of An Industrial Fabrication Process For Next Generation, Thinner And Larger Crystalline Silicon (C-Si) Wafer-Based Solar Cells, Anh Viet Nguyen

Legacy Theses & Dissertations (2009 - 2024)

The world's solar cell production has grown rapidly and steadily with an annual average of 30% over the last two decades. Single and micro-crystalline silicon solar cells have been the major reason for this production increase. In 2009, silicon-based solar cells comprised almost 90% of worldwide photovoltaic module shipments.