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2008

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Articles 811 - 840 of 997

Full-Text Articles in Civil and Environmental Engineering

Cyanobacterial Harmful Algal Blooms: Chapter 1: An Overview Of The Interagency, International Symposium On Cyanobacterial Harmful Algal Blooms (Isoc-Hab): Advancing The Scientific Understanding Of Freshwater Harmful Algal Blooms, H. Kenneth Hudnell, Quay Dortch, Harold Zenick Jan 2008

Cyanobacterial Harmful Algal Blooms: Chapter 1: An Overview Of The Interagency, International Symposium On Cyanobacterial Harmful Algal Blooms (Isoc-Hab): Advancing The Scientific Understanding Of Freshwater Harmful Algal Blooms, H. Kenneth Hudnell, Quay Dortch, Harold Zenick

United States Environmental Protection Agency: Publications

There is growing evidence that the spatial and temporal incidence of harmful algal blooms is increasing, posing potential risks to human health and ecosystem sustainability. Currently there are no US Federal guidelines, Water Quality Criteria and Standards, or regulations concerning the management of harmful algal blooms. Algal blooms in freshwater are predominantly cyanobacteria, some of which produce highly potent cyanotoxins. The US Congress mandated a Scientific Assessment of Freshwater Harmful Algal Blooms in the 2004 reauthorization of the Harmful Algal Blooms and Hypoxia Research and Control Act. To further the scientific understanding of freshwater harmful algal blooms, the US Environmental …


Cyanobacterial Harmful Algal Blooms: Chapter 35: Risk Assessment Workgroup Report, Joyce Donohue, Jennifer Orme–Zavaleta, Michael Burch, Daniel Dietrich, Belinda Hawkins, Tony Lloyd, Wayne Munns, Jeffery Steevens, Dennis Steffensen, Dave Stone, Peter Tango Jan 2008

Cyanobacterial Harmful Algal Blooms: Chapter 35: Risk Assessment Workgroup Report, Joyce Donohue, Jennifer Orme–Zavaleta, Michael Burch, Daniel Dietrich, Belinda Hawkins, Tony Lloyd, Wayne Munns, Jeffery Steevens, Dennis Steffensen, Dave Stone, Peter Tango

United States Environmental Protection Agency: Publications

Risk assessment is a four–stage process used in evaluating the impact of contaminants on the well being of individuals, populations and/or the physical environment. As defined by the National Academy of Sciences (1983), the four components are as follows: hazard identification, dose– response assessment, exposure assessment and risk characterization.
The goal of a risk assessment is to utilize existing information coupled with site specific data to quantitatively characterize the potential risk of a stressor to an identified receptor(s). Quantitative, risk–based estimates of dose–response relationships integrated with exposure scenarios and information on environmental conditions often become the basis for regulatory measures …


Cyanobacterial Harmful Algal Blooms: Chapter 26: Human Health Effects Workgroup Report, Sandra Azevedo, Neil Chernoff, Ian Falconer, Michael Gage, Elizabeth Hilborn, Michelle Hooth, Karl Jensen, Robert Macphail, Ellen Rogers, Glen Shaw, Ian Stewart Jan 2008

Cyanobacterial Harmful Algal Blooms: Chapter 26: Human Health Effects Workgroup Report, Sandra Azevedo, Neil Chernoff, Ian Falconer, Michael Gage, Elizabeth Hilborn, Michelle Hooth, Karl Jensen, Robert Macphail, Ellen Rogers, Glen Shaw, Ian Stewart

United States Environmental Protection Agency: Publications

Two types of approaches may be used to evaluate the toxicity of environmental agents:

• Observational population studies may be used to investigate humans or animals in contact with the agent of interest, either prospectively or retrospectively.
• Experimental studies may be performed under controlled conditions on animals, living tissues or cells. These results may be extrapolated to human and animal populations.

Observational epidemiological studies of human and animal populations have the advantage of investigating the effects of environmentally relevant exposures to naturally–occurring mixtures of toxins. Health effects may be identified in the target species of concern. These studies are …


Cyanobacterial Harmful Algal Blooms: Chapter 38: Integrating Human And Ecological Risk Assessment: Application To The Cyanobacterial Harmful Algal Bloom Problem, Jennifer Orme-Zavaleta, Wayne Munns, Jr. Jan 2008

Cyanobacterial Harmful Algal Blooms: Chapter 38: Integrating Human And Ecological Risk Assessment: Application To The Cyanobacterial Harmful Algal Bloom Problem, Jennifer Orme-Zavaleta, Wayne Munns, Jr.

United States Environmental Protection Agency: Publications

Environmental and public health policy continues to evolve in response to new and complex social, economic and environmental drivers. Globalization and centralization of commerce, evolving patterns of land use (e.g., urbanization, deforestation), and technological advances in such areas as manufacturing and development of genetically modified foods have created new and complex classes of stressors and risks (e.g., climate change, emergent and opportunist disease, sprawl, genomic change). In recognition of these changes, environmental risk assessment and its use are changing from stressor-endpoint specific assessments used in command and control types of decisions to an integrated approach for application in communitybased decisions. …


Cyanobacterial Harmful Algal Blooms: Chapter 15: Cyanotoxins Workgroup Report, Rex Pegram, Andrew Humpage, Brett Neilan, Maria Runnegar, Tonya Nichols, Robert Thacker, Stephan Pflugmacher, Stacey Etheridge, Adam Love Jan 2008

Cyanobacterial Harmful Algal Blooms: Chapter 15: Cyanotoxins Workgroup Report, Rex Pegram, Andrew Humpage, Brett Neilan, Maria Runnegar, Tonya Nichols, Robert Thacker, Stephan Pflugmacher, Stacey Etheridge, Adam Love

United States Environmental Protection Agency: Publications

The Cyanotoxins Workgroup was charged with the identification and prioritization of research needs associated with: the identification of cyanotoxins; toxicokinetics and toxicodynamics of cyanotoxins; human susceptibility to the toxins; cyanobacterial genetics/omics and factors for inclusion in predictive models of toxin production; and risk reduction from an intentional or accidental release of cyanotoxins. Papers presented for the Cyanotoxins Session of the symposium on toxin types, toxicokinetics, and toxicodyamics (See Humpage this volume), cyanobacterial genetics of toxin production (See Neilan this volume), and parameters related to human risks from cyanobacterial exposure (See Love this volume) set the stage for Cyanotoxins Workgroup discussions. …


Cyanobacterial Harmful Algal Blooms: Chapter 2: A Synopsis Of Research Needs Identified At The Interagency, International Symposium On Cyanobacterial Harmful Algal Blooms (Isoc-Hab), H. Kenneth Hudnell, Quay Dortch Jan 2008

Cyanobacterial Harmful Algal Blooms: Chapter 2: A Synopsis Of Research Needs Identified At The Interagency, International Symposium On Cyanobacterial Harmful Algal Blooms (Isoc-Hab), H. Kenneth Hudnell, Quay Dortch

United States Environmental Protection Agency: Publications

Evidence indicates that the incidence of cyanobacterial harmful algal blooms (CHABs) is increasing in spatial extent and temporal frequency worldwide. Cyanobacterial blooms produce highly potent toxins and huge, noxious biomasses in surface waters used for recreation, commerce, and as drinking water sources. The Interagency, International Symposium on Cyanobacterial Harmful Algal Blooms (ISOC-HAB) characterized the state of the science and identified research needed to address the risks posed by CHABs to human health and ecosystem sustainability. This chapter provides a synopsis of CHAB research needs that were identified by workgroups that addressed charges in major topic areas. The research and infrastructure …


Cyanobacterial Harmful Algal Blooms: Chapter 3: Occurrence Of Cyanobacterial Harmful Algal Blooms Workgroup Report, Anthony Fristachi, James Sinclair, Sherwood Hall, Julie Hambrook Berkman, Greg Boyer, Joann Burkholder, John Burns, Wayne Carmichael, Al Dufour, William Frazier, Steve Morton, Eric O’Brien, Steven Walker Jan 2008

Cyanobacterial Harmful Algal Blooms: Chapter 3: Occurrence Of Cyanobacterial Harmful Algal Blooms Workgroup Report, Anthony Fristachi, James Sinclair, Sherwood Hall, Julie Hambrook Berkman, Greg Boyer, Joann Burkholder, John Burns, Wayne Carmichael, Al Dufour, William Frazier, Steve Morton, Eric O’Brien, Steven Walker

United States Environmental Protection Agency: Publications

Freshwater cyanobacteria periodically accumulate, or bloom, in water bodies across the United States (US). These blooms, also known as cyanobacterial harmful algal blooms (CHAB), can lead to a reduction in the number of individuals who engage in recreational activities in lakes and reservoirs, degrade aquatic habitats and potentially impact human health. In 1998, Congress passed the 1998 Harmful Algal Bloom and Hypoxia Research and Control Act (HABHRCA) to address CHABs that impacted living marine resources, fish and shellfish harvests and recreational and service industries along US coastal waters. In 2004, as part of its reauthorization, HABHRCA requires federal agencies to …


Nitrogen In The Environment: Chapter 22. New Policy Directions, A.P. Manale Jan 2008

Nitrogen In The Environment: Chapter 22. New Policy Directions, A.P. Manale

United States Environmental Protection Agency: Publications

Advances in linking the science of ecology with economics and the development of agri-environmental modeling systems coupled with new information technology suggest new public policy approaches that reward agricultural producers for providing ecological services. An incentive-based ecosystem approach that identifies and quantifies an array of environmental services that can be provided by agricultural land, and then facilitates the development of markets in these services can protect environmental quality while improving farm income. Sustainability can be achieved whereby economic needs of society are integrated into environmental protection. Before presenting new agricultural policy approaches for improving environmental quality and, in particular, managing …


Bridging The Gaps Between Design And Use: Developing Tools To Support Environmental Management And Policy, B. S. Mcintosh, C. Giupponi, A. A. Voinov, C. Smith, K. B. Matthews, M. Monticino, M. J. Kolkman, N. Crossman, M. Van Ittersum, D. Haase, A. Haase, J. Mysiak, J. Groot, S. Sieber, P. Verweij, N. Quinn, P. Waeger, N. Gaber, D. Hepting, H. Scholten, A. Sulis, H. Van Delden, E. Gaddis, H. Assaf Jan 2008

Bridging The Gaps Between Design And Use: Developing Tools To Support Environmental Management And Policy, B. S. Mcintosh, C. Giupponi, A. A. Voinov, C. Smith, K. B. Matthews, M. Monticino, M. J. Kolkman, N. Crossman, M. Van Ittersum, D. Haase, A. Haase, J. Mysiak, J. Groot, S. Sieber, P. Verweij, N. Quinn, P. Waeger, N. Gaber, D. Hepting, H. Scholten, A. Sulis, H. Van Delden, E. Gaddis, H. Assaf

United States Environmental Protection Agency: Publications

Sound decisions in environmental policy and management usually require the examination of alternative solutions, and may require the consideration of alternative problem fornlulations prior to option assessment. Constructing and considering the consequences of alternative problems (variables and relations) and policy options (norms and standards) is fundamental for processes of policy fornlulation (Vickers, 1965).


Complexity And Uncertainty: Rethinking The Modelling Activity, M. Brugnach, C. Pahl-Wostl, K. E. Lindenschmidt, J. A.E.B. Janssen, T. Filatova, A. Mouton, G. Holtz, P. Van Der Keur, N. N. Gaber Jan 2008

Complexity And Uncertainty: Rethinking The Modelling Activity, M. Brugnach, C. Pahl-Wostl, K. E. Lindenschmidt, J. A.E.B. Janssen, T. Filatova, A. Mouton, G. Holtz, P. Van Der Keur, N. N. Gaber

United States Environmental Protection Agency: Publications

Complexity and uncertainty have become critical considerations for environmental modelling applications, opening ne\v avenues for the use and development of models. Increasingly l110dels are being recognized as essential tools to learn, coml11unicate, explore and resolve the particulars of complex environmental problems (Sterman, 2002; Van den Belt, 2(04). However, this shift in the way in which models have been used has not always been accompanied by a concomitant shift in the way in which models have been conceived and implemented. Too often, models were conceived and built as predictive devices, aimed at capturing single, best, objective explanations. Considerations of uncertainty were …


2008 Epa’S Report On The Environment: Indicators Presenting Data For Epa Region 7, United States Environmental Protection Agency Jan 2008

2008 Epa’S Report On The Environment: Indicators Presenting Data For Epa Region 7, United States Environmental Protection Agency

United States Environmental Protection Agency: Publications

EPA’s 2008 Report on the Environment (ROE) compiles, in one place, the most reliable indicators currently available to answer 23 questions that EPA believes are of critical importance to its mission to protect human health and the environment.
The indicators are supported by data gathered from federal and state agencies and non-governmental organizations. All ROE indicators were peer-reviewed to meet exacting standards for accuracy, representativeness, and reliability, and the report has undergone extensive internal and interagency review, SAB review, and public comment. The indicators present trends wherever adequate data are available, and establish national baselines where they are not. The …


Formal Scenario Development For Environmental Impact Assessment Studies., Y. Liu, M. Mahmoud, H. Hartmann, S. Stewart, T. Wagener, D. Semmens, R. Stewart, H. Gupta, D. Dominguez, D. Hulse, R. Letcher, B. Rashleigh, C. Smith, R. Street, J. Ticehurst, M. Twer, H. Van Delden, D. White Jan 2008

Formal Scenario Development For Environmental Impact Assessment Studies., Y. Liu, M. Mahmoud, H. Hartmann, S. Stewart, T. Wagener, D. Semmens, R. Stewart, H. Gupta, D. Dominguez, D. Hulse, R. Letcher, B. Rashleigh, C. Smith, R. Street, J. Ticehurst, M. Twer, H. Van Delden, D. White

United States Environmental Protection Agency: Publications

Scenario analysis is the process of evaluating possible future events through the consideration of alternative plausible, though not equally likely, states (scenarios). The definition by the Intergovernmental Panel on Climate Change (IPCC) best represents scenarios considered in the natural sciences:

"A scenario is a coherent) internally consistent and plausible description of a possible future state of the world. It is not a forecast; rather, each scenario is one alternative image ~fhow the future can unfold."(http://ipcc-ddc.cru. uea.ac.uk/ ddc_definitions. htnll)


Good Modelling Practice, N. Crout, T. Kokkonen, A.J. Jakeman, J.P. Norton, L.T.H. Newham, R. Anderson, H. Assaf, B.F.W. Croke, N. Gaber, J. Gibbons, D. Holzworth, J. Mysiak, J. Reichl, R. Seppelt, T. Wagener, P. Whitfield Jan 2008

Good Modelling Practice, N. Crout, T. Kokkonen, A.J. Jakeman, J.P. Norton, L.T.H. Newham, R. Anderson, H. Assaf, B.F.W. Croke, N. Gaber, J. Gibbons, D. Holzworth, J. Mysiak, J. Reichl, R. Seppelt, T. Wagener, P. Whitfield

United States Environmental Protection Agency: Publications

Best-practice guidelines for Modelling have been developed by a numbers of organizations to promote better understanding of model development and application, facilitate tests of model quality and provide a framework for documenting and communicating modelling activities among modellers and decision makers. Good practice within a Data Mining paradigm is presented in Chapter 12.


Missouri River Recovery Program Bald Eagles And Cottonwood Trees: A Dynamic Duo Jan 2008

Missouri River Recovery Program Bald Eagles And Cottonwood Trees: A Dynamic Duo

United States Army Corps of Engineers, Omaha District

Cottonwood trees are essential to the preservation of the mighty bald eagle along the Missouri River. Bald eagles come to the Missouri River to nest, to
rest during migration and to roost over the winter. Eagles prefer to nest, rest and roost in cottonwood trees because they are sturdy enough to support large nests and are located in areas with plentiful food sources. To survive and reproduce, cottonwood trees require certain levels of soil moisture and nutrients, which historically were provided regularly by the Missouri River’s floods.

The symbol of our country and the only sea eagle native to North …


Dynamic Impact Testing Of Crt Wood Posts In A Rigid Sleeve, Steven W. Arens, Ronald K. Faller, John R. Rohde, Karla A. Polivka Jan 2008

Dynamic Impact Testing Of Crt Wood Posts In A Rigid Sleeve, Steven W. Arens, Ronald K. Faller, John R. Rohde, Karla A. Polivka

Mid-America Transportation Center: Final Reports and Technical Briefs

Dynamic impact testing was performed on 152-mm x 203-mm (6-in. x 8-in.) CRT wood posts placed in a rigid sleeve at various angles. A total of nine bogie tests were performed with three tests each at 0, 90, and 45 degree rotation angles relative to the strong axis of bending. For each bogie test, the raw acceleration data was obtained from accelerometers and was filtered. Then, force-displacement and energy-displacement graphs were plotted. Based on the results, the properties and strengths of the CRT wood posts at the different impact angles were determined. The results of this study will be the …


Transportation Security Framework For A Medium-Sized City, Ryan Fries, Mashrur Chowdhury, Anne Dunning Jan 2008

Transportation Security Framework For A Medium-Sized City, Ryan Fries, Mashrur Chowdhury, Anne Dunning

Publications

Terrorist attacks have made security preparedness unquestionably necessary in all cities. While major metropolitan areas have long recognized that their global visibility has required strong security operations, many medium-sized cities, specifically those of the U.S. and European Union, now face the need to establish transportation security frameworks for the first time. This paper assesses the resources available to help medium-sized cities begin the task of creating such systems. This assessment presents infrastructure risk assessment tools, identifies infrastructure and funding resources, and creates a process for developing a security framework to connect agencies responsible for transportation security in these metropolitan areas. …


Catfish Consumption As A Contributor To Elevated Pcb Levels In A Non-Hispanic Black Subpopulation, Max Weintraub, Linda S. Birnbaum Jan 2008

Catfish Consumption As A Contributor To Elevated Pcb Levels In A Non-Hispanic Black Subpopulation, Max Weintraub, Linda S. Birnbaum

United States Environmental Protection Agency: Publications

The human body burden of polychlorinated biphenyls (PCBs) sharply declined after production was banned in the US in 1979. For the 10% of the US population that remains most exposed to PCBs, fish consumption is the primary source. National Health and Nutrition Examination Survey (NHANES) data indicates that the highest remaining PCB levels exist in a non-Hispanic black subpopulation. Our review suggests that catfish consumption may be a significant PCB source for the one million non-Hispanic black anglers who fish for catfish. In comparison to non-Hispanic white anglers, non-Hispanic black anglers consume more catfish, are more likely to eat the …


The History Of The Unl Water Center From 1964, Water Center, School Of Natural Resources Jan 2008

The History Of The Unl Water Center From 1964, Water Center, School Of Natural Resources

Nebraska Water Center: Administrative Materials

Water is an integral part of Nebraska’s economy and well being in a state that depends on an adequate supply for all uses, including agricultural, municipal, industrial, recreational and wildlife habitat.

Nebraska is fortunate with regard to its water supply, having tremendous groundwater reserves which are estimated to be in excess of two billion acrefeet (an acre-foot being enough water to cover one acre of land with a foot of water, or approximately 325,000 gallons), combined with an estimated annual precipitation of 86 million acre-feet and annual average surface water inflows of 1.7 million acre-feet, give the state adequate supplies …


Clay Mineralogy Effects On Long-Term Performance Of Chemically Treated Expansive Clays, Bhaskar Chandra Srinivas Chittoori Jan 2008

Clay Mineralogy Effects On Long-Term Performance Of Chemically Treated Expansive Clays, Bhaskar Chandra Srinivas Chittoori

Civil Engineering Dissertations - Archive

Stabilization of expansive soils using chemical additives such as cement and lime had been in use for several decades and these treatments provide riding comforts to travelers. However, many state Departments of Transportation (DOTs) in the United States have had problems with subgrade failure even after stabilization with chemical additives due to a loss of stabilizer over time, or a stabilizer being ineffective in some soils while other soils with the same index properties respond well to that stabilizer. These problems are attributed to the limitations of the current procedures of stabilization for pavement subsoil layers. One such limitation is …


Construction Cost Of Underground Infrastructure, Seyed Behnam Hashemi Jan 2008

Construction Cost Of Underground Infrastructure, Seyed Behnam Hashemi

Civil Engineering Theses - Archive

Renewal of aging underground infrastructure is a major challenge that municipalities inNorth America face every day. Traditional replacement or renewal of these underground utilitiesuses open-cut excavation methods that can be disruptive to everyday life of citizens andexpensive, particularly in built-up areas and in projects with difficult ground and site conditions. Incontrast, trenchless technologies use innovative methods, materials, and equipment that requireminimum surface excavation to renew and construct aging underground infrastructure. Thesenew methods are considered to be more safe, cost-effective, efficient and productive thanconventional open-cut projects. However, to select trenchless technologies in utility design,consulting engineers and utility owners need to compare …


Adsorption Curve Fits For Landfill Vocs On Bituminous Coal Based And Coconut Shell Based Activated Carbon, Annaprabha Athappan Jan 2008

Adsorption Curve Fits For Landfill Vocs On Bituminous Coal Based And Coconut Shell Based Activated Carbon, Annaprabha Athappan

Civil Engineering Theses - Archive

This study explores adsorption as a method of controlling hazardous gas emissions from Municipal Solid Waste Landfills (MSWL). In particular, the hazardous air pollutants (HAPs) para, meta, and ortho-xylene, ethylbenzene and methyl ethyl ketone are selected for experimental study. Activated carbon is a good adsorbent and well known for its high surface area. Among the many varieties of activated carbon, bituminous coal based activated carbon (BPL) and coconut shell based activated carbon (OVC) are compared in this study. Each experiment was conducted in a vial with a known amount of carbon in it. The pollutant concentration remaining in the vial …


Assessing Control Strategies For Ground Level Ozone, Neelesh Vijay Sule Jan 2008

Assessing Control Strategies For Ground Level Ozone, Neelesh Vijay Sule

Civil Engineering Dissertations - Archive

Developing cost effective control strategies for ozone has been a challenge to air quality modelers. Conventionally, the control strategies are applied across-the board to the region. The main aim of this research was to develop a Decision-Making Framework (DMF) for evaluating and optimizing the selection of ozone control strategies. Conventional across-the-board reductions conduct emission reductions uniformly throughout the region and throughout the day. By contrast, this dissertation studied targeted reductions, in which emission sources of various types are reduced at various times and locations. The proposed DMF comprised of four phases: (1) Initialization, (2) Mining, (3) Metamodeling, and (4) Optimization. …


Measured And Theoretical Response Of Perpetual Pavement Structures, Miguel M. Portillo Jan 2008

Measured And Theoretical Response Of Perpetual Pavement Structures, Miguel M. Portillo

Civil Engineering Theses - Archive

The Kansas Perpetual Pavement experiment includes the construction of four pavement sections on the US-75 highway designed according to the perpetual pavement concept. The sections were instrumented with strain gauges and pressures cells to measure strains and stress at the bottom of the base layer and at the top of the subbase layer. Pavement response measurements were carried out in seven occasions between July 2005 and October 2007 with a loaded truck. Measured values obtained show that longitudinal and transverse values were almost always below the average endurance limit of 70 microstrains. The measurements also showed that temperature and vehicle …


Evaluation Of The Effectiveness Of Pavement Rumble Strips, Adam Kirk Jan 2008

Evaluation Of The Effectiveness Of Pavement Rumble Strips, Adam Kirk

Kentucky Transportation Center Research Report

This report analyzes the effectiveness of continuous shoulder rumble strips (CSRS) and center line rumble strips (CLRS) on rural two lane roads in Kentucky. This study evaluates the safety benefits, and design details associated with the application of the CSRS and CLRS. The recommended practices proposed as a result of the crash analysis have the potential to reduce both run off the road and opposite direction crashes on rural two lane roads in Kentucky. These recommendations provide benefits for narrow roadways with little to no shoulder as well as larger roadways with wider paved shoulders.


Use Of Edge Line Markings On Rural Two-Lane Highways, Kenneth R. Agent, Eric R. Green Jan 2008

Use Of Edge Line Markings On Rural Two-Lane Highways, Kenneth R. Agent, Eric R. Green

Kentucky Transportation Center Research Report

The objective of this study was to review roadway characteristics and crash data in Kentucky and determine if revisions should be made to current guidelines for the use of edge lines. Recommendations were made concerning the use of edge lines, centerlines, and paved shoulders on rural, two-lane roadways with varying pavement widths.


Statistical Approach To The Development Of A Microscale Model For Estimating Exhaust Emissions Of Light Duty Gasoline Vehicles, Benjamin Nmai Afotey Jan 2008

Statistical Approach To The Development Of A Microscale Model For Estimating Exhaust Emissions Of Light Duty Gasoline Vehicles, Benjamin Nmai Afotey

Civil Engineering Dissertations - Archive

Today, air pollution is taking a growing toll on human health, the environment and the economy, despite decades of efforts to combat it. Although it was once a primary urban phenomenon in industrialized countries, today air pollution has spread worldwide. Mobile, industrial and natural sources constitute the major sources of air pollution. Around the world, major cities in industrialized countries have in recent times been battling air pollution from mobile sources. Beijing, New Delhi, Dallas/ Fort Worth and Los Angeles are no exceptions.Pronounced interest has focused on mobile source (vehicle exhaust) emissions in recent decades. A rapid increase in the …


Multi-Criteria Assessment For Supporting Freeway Operations And Management Systems, Auttawit Upayokin Jan 2008

Multi-Criteria Assessment For Supporting Freeway Operations And Management Systems, Auttawit Upayokin

Civil Engineering Dissertations - Archive

Freeway traffic congestion represents an increasing concern for urban areas throughout the United States. In addition, faced with limited roadway expansion alternatives, transportation agencies are considering investment in traffic management centers (TMCs) as a more viable way to operate and manage freeways effectively. The TMCs' responsibilities include monitoring roadway conditions using the various data collection strategies and determining performance measures for freeway operations. At the same time, traffic engineers at the TMCs may react to the traffic congestion problems by implementing operational strategies. In order to provide reliable decision support for TMC freeway operations and management systems, this dissertation aims …


Capacity Of Two-Sided Type C On Freeway With Four Lanes, Shadi Ghasemi-Majd Jan 2008

Capacity Of Two-Sided Type C On Freeway With Four Lanes, Shadi Ghasemi-Majd

Civil Engineering Theses - Archive

Weaving segments are categorized based on weaving length, configuration, number of lanes, free flow speed and weaving ratio. All these parameters affect weaving capacity. One of the objectives of this research was to extend Phong Thanh Vo's dissertation and study the relation between weaving capacity of two-sided type C on freeways with four lanes and any potential variables (mainalane demand, entrance ramp demand, exit ramp demand and weaving ratio). Micro-simulation has been used in order to analyze different capacity scenarios and the VISSIM calibrated model by Vo was used. Also, the effect of each of the VISSIM calibration parameters on …


The Effect Of Displacement Control Loading Histories On Genral Connecting Surfaces Using Finite Element Analysis, Sanjog Chandrakant Sabnis Jan 2008

The Effect Of Displacement Control Loading Histories On Genral Connecting Surfaces Using Finite Element Analysis, Sanjog Chandrakant Sabnis

Civil Engineering Theses - Archive

Displacement loading history provided by the AISC Seismic Provision 2002 is commonly used for experimental testing and analytical modeling of beam-to-column steel connection to stimulate the seismic effect. However, the basis for the above loading history is not documented in the literature. Thus, this study developed 25 cyclic load cases by varying the frequency and magnitude of the AISC-2002 loading within a predefined envelops. The 25 load cases are obtained from five different load sets in which the concept of uniform and non-uniform frequencies and amplitude are utilized. All the load cases are limited to the displacement equivalent to the …


Clay Mineral Quantification Using Gravemetric Analysis, Sarwenaj Ashraf Jan 2008

Clay Mineral Quantification Using Gravemetric Analysis, Sarwenaj Ashraf

Civil Engineering Theses - Archive

The current procedure used by the Texas Department of Transportation (TxDOT) to determine the type of stabilizer is based mainly on the Plasticity Index (PI) and the gradation of the soil. This method of stabilization does not always work because two soils with the same PIs can have very different shrink/swell potential, plastic limits or liquid limits, hence their behavior may be very different. This is mainly due to the fact that two soils that have the same PI can have very different clay mineral composition. Montmorillonite and kaolinite are the clay minerals that cause swelling/shrinking in soils.Chittoori (2008) had …