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2006

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Articles 391 - 420 of 604

Full-Text Articles in Civil and Environmental Engineering

Automated Manipulation For The Lotus Filament Winding Process, Jeffrey V. Anderson Mar 2006

Automated Manipulation For The Lotus Filament Winding Process, Jeffrey V. Anderson

Theses and Dissertations

The filament-winding process produces quality consistent composite parts for many industries. Filament winding allows for consistent quality parts by automating the winding process. A recent development of filament winding is the Lotus process. The Lotus process reverses conventional filament winding by leaving the mandrel stationary and winding composite fiber around the mandrel. The automated Lotus filament-winding machine is controlled by four-axis control manipulating the Lotus ring around a fixed mandrel. This allows Lotus filament winding to wind parts that do not have a linear axis. Lotus filament winding is in its early stages of development. As a second step in …


Investigation Of Copper Contamination And Corrosion Scale Mineralogy In Aging Drink Water Distributions Systems, Nadja F. Turek Mar 2006

Investigation Of Copper Contamination And Corrosion Scale Mineralogy In Aging Drink Water Distributions Systems, Nadja F. Turek

Theses and Dissertations

Research has shown higher levels of copper appear in drinking water conveyed through relatively new copper piping systems; older piping systems typically deliver lower copper levels in their drinking water. This research contributes field data from a real drinking water distribution system, providing a better understanding of this phenomenon, as it relates to treatment considerations and compliance with the Lead and Copper Rule. Copper pipes and copper levels were sampled from drinking water taps of 16 buildings with pipes ranging in age from less than 1 to 48 years. Water samples from each building were collected before and following a …


Bearing Capacity Of Foundations On Sand Using The Method Of Slip Line, Meen-Wah Gui, Muhunthan Mar 2006

Bearing Capacity Of Foundations On Sand Using The Method Of Slip Line, Meen-Wah Gui, Muhunthan

Journal of Marine Science and Technology–Taiwan

The accurate prediction of the bearing capacity of shallow foundations on granular soils has been complicated by their stress dependent strength behavior and the surface roughness of the foundationsoil interface. These are accounted for using empirical relations in the current state of practice. In this study, the stress dependent behavior of soils is accounted for using a strength dilatancy relationship. The method of slip line has been extended to incorporate this relationship and the effects of surface roughness to derive the depth dependent bearing capacity factor Nq. The results are presented in terms of angle of friction, depth/diameter ratio, and …


Modeling Study To Quantify The Benefits Of Groundwater Contaminant Source Remediation, David E. Wagner Mar 2006

Modeling Study To Quantify The Benefits Of Groundwater Contaminant Source Remediation, David E. Wagner

Theses and Dissertations

The purpose of this research was to quantify the benefits of groundwater contaminant source remediation by using a model to simulate how reduction of source mass was related to reduction of contaminant concentration at a receptor. This thesis sought to answer three research questions: (1) how are contaminant source mass reduction and reduction of mass flux leaving the source-zone related; (2) how can we quantify the effect of the important natural attenuation processes that act upon the dissolved contaminant as it travels from the source zone to downgradient receptors, and (3) under specified site conditions, what is the maximum contaminant …


A Decision Model For Choosing Among Photovoltaic Technologies To Generate Electricity At Grid-Connected Air Force Facilities: A Value-Focused Approach, Mostyn O. Kellner Mar 2006

A Decision Model For Choosing Among Photovoltaic Technologies To Generate Electricity At Grid-Connected Air Force Facilities: A Value-Focused Approach, Mostyn O. Kellner

Theses and Dissertations

The United States is currently consuming fossil fuels faster than natural processes can replace them. Our nation's leaders recognize that a diverse energy portfolio including renewable energy is the key to maintaining our economy, security, and the environment. The federal government is by far the greatest energy consumer; thus, our nation's leaders have directed federal agencies to strive to increase the use of renewable energy at federal facilities. Solar electricity technologies, in the form of photovoltaics, have great potential in the renewable energy mix. Although a major strategy should be integrating photovoltaics into the design of new facilities, an important …


Normalizing The Cpt For Overburden Stress, Robb E.S. Moss, Raymond B. Seed, Richard S. Olsen Mar 2006

Normalizing The Cpt For Overburden Stress, Robb E.S. Moss, Raymond B. Seed, Richard S. Olsen

Civil and Environmental Engineering

Effective overburden stress can have a significant influence on cone penetration test (CPT) measurements. This influence can lead to an incorrect assessment of soil strength/resistance for such purposes as liquefaction triggering analysis. For an accurate measurement of tip and sleeve resistance, unbiased by overburden stress, it is essential to normalize these index measurements appropriately. Presented herein is a comprehensive study reviewing all aspects of CPT normalization. A result of this study is a variable normalization procedure for the CPT that is based on both empirical results and theoretical analysis. This paper presents these results in the form of an improved …


Atms Implementation System For Identifying Traffic Conditions Leading To Potential Crashes, Mohamed Abdel-Aty, Anurag Pande Mar 2006

Atms Implementation System For Identifying Traffic Conditions Leading To Potential Crashes, Mohamed Abdel-Aty, Anurag Pande

Civil and Environmental Engineering

Predicting a crash occurrence is the key to traffic safety. Real-time identification of freeway segments with high crash potential is addressed in this paper. For this study, historical crashes and corresponding traffic-surveillance data from loop detectors were gathered from a 36-mi corridor of Interstate 4 for 4 years. Following an exploratory analysis, two types of logistic-regression models (i.e., simple and multivariate) were developed. It was observed that, although the simple models have the advantage of being tolerant in their data requirements, their classification accuracy was inferior to that of the final multivariate model. Hence, the simple models were used to …


Estimating Required Contingency Funds For Construction Projects Using Multiple Linear Regression, Jason J. Cook Mar 2006

Estimating Required Contingency Funds For Construction Projects Using Multiple Linear Regression, Jason J. Cook

Theses and Dissertations

Cost overruns are a critical problem for construction projects. The common practice for dealing with cost overruns is the assignment of an arbitrary flat percentage of the construction budget as a contingency fund. This research seeks to identify significant factors that may influence, or serve as indicators of, potential cost overruns. The study uses data on 243 construction projects over a full range of project types and scopes gathered from an existing United States Air Force construction database. The author uses multiple linear regression to analyze the data and compares the proposed model to the common practice of assigning contingency …


Analysis Of Bacterial Population And Distribution In The Developing Strata Of A Constructed Wetland Used For Chlorinated Ethene Bioremediation, Milton J. Clausen Jr. Mar 2006

Analysis Of Bacterial Population And Distribution In The Developing Strata Of A Constructed Wetland Used For Chlorinated Ethene Bioremediation, Milton J. Clausen Jr.

Theses and Dissertations

Chlorinated hydrocarbons and their degradation products are among of the most common organic groundwater contaminates in the United States. These compounds attack the central nervous system in animals and can affect the photosynthesis of plants. These compounds are also resistant to degradation in the environment and, because of this, pose a risk to any ecosystem in which they are present. This study identified the dominant microbial species in a constructed treatment wetland at Wright-Patterson AFB, Dayton, Ohio using 16S rRNA gene sequence analysis. Samples were taken from three different depths and during each of the four seasons. These samples were …


Evaluation Of Work Zone Safety Operations And Issues, Jerry G. Pigman, Kenneth R. Agent, Eric R. Green Mar 2006

Evaluation Of Work Zone Safety Operations And Issues, Jerry G. Pigman, Kenneth R. Agent, Eric R. Green

Kentucky Transportation Center Research Report

Work zone activities are one of the areas with a high potential for compromised safety for workers and road users. Various measures have been taken to increase the level of safety in work zones; including the use of double fines for speeding and the application of speed displays based on radar detection. There has been an effort to improve the effectiveness and safety of flaggers by requiring the use of a stop/slow paddle for most work zone conditions, using lights on the paddle, and increasing visibility by using more reflective clothing. It has been suggested that safety in work zones …


Baseline Modeling Of The Owensboro Cable-Stayed Bridge Over The Ohio River, Jindong Hu, Issam E. Harik, Suzanne Weaver Smith, Jeff Gagel, Jennie E. Campbell, R. Clark Graves Mar 2006

Baseline Modeling Of The Owensboro Cable-Stayed Bridge Over The Ohio River, Jindong Hu, Issam E. Harik, Suzanne Weaver Smith, Jeff Gagel, Jennie E. Campbell, R. Clark Graves

Kentucky Transportation Center Research Report

This report presents the baseline modeling of the Owensboro cable-stayed bridge which connects Owensboro, Kentucky and Rockport, Indiana over the Ohio River. The objective of this study is to establish the bridge baseline model via the dynamics-based technique and finite element method. The scope of research includes finite element modeling and modal analysis, field free vibration testing, finite element model calibration using field test results, and cable dynamic testing and modeling. It is demonstrated that a cable-stayed bridge is a highly pre-stressed structure. The stress stiffening of cable elements plays an important role in both static and dynamic analysis. The …


Performance Evaluation Of Bridges With Structural Bridge Deck Overlays (Sbdo), James J. Griffin, Issam E. Harik, Ching Chiaw Choo Mar 2006

Performance Evaluation Of Bridges With Structural Bridge Deck Overlays (Sbdo), James J. Griffin, Issam E. Harik, Ching Chiaw Choo

Kentucky Transportation Center Research Report

Structural Bridge Deck Overlay (SBDO) involves applying 6 to 10 inches (150 to 200 mm) of normal weight, class AA, reinforced concrete directly to a bridge’s original slab. The overlay is designed to increase the deck elevation to an extent that standard highway resurfacing procedures can continue uninterrupted up the edges of the bridge. Otherwise, excavation along the bridge approaches or jacking of the superstructure is required to insure proper elevation.

Experimental static field tests were conducted on three different bridges: (1) Simply supported prestressed concrete I-girder bridge; (2) cast-in-place reinforced concrete continuous haunched girder bridge; and (3) cast-in-place reinforced …


Inspection And Evaluation Of A Bridge Deck Reinforced With Carbon Fiber Reinforced Polymer (Cfrp) Bars, Choo Ching Chiaw, Issam E. Harik Mar 2006

Inspection And Evaluation Of A Bridge Deck Reinforced With Carbon Fiber Reinforced Polymer (Cfrp) Bars, Choo Ching Chiaw, Issam E. Harik

Kentucky Transportation Center Research Report

Cracking in reinforced concrete decks is inevitable. It leads to the corrosion and eventual deterioration of the deck system. The use of non-corrosive reinforcement is one alternative to steel in reinforced concrete construction. This report deals with the field evaluation and performance of a concrete bridge deck reinforced with carbon fiber reinforced polymer (CFRP) bars. The bridge is identified as the Elkin Station Road Bridge on route CR1210 over the Two Mile Creek in Clark County, KY. The CFRP bars were placed in the top and bottom mats of the bridge deck in both the transverse and longitudinal directions. The …


Intersection Safety, Aemal Khattak Mar 2006

Intersection Safety, Aemal Khattak

Nebraska Department of Transportation: Research Reports

The objectives of this project included a study to determine the safety effects of intersection type (unsignalized, signalized, and interchange) on Nebraska expressway intersections, quantification of the safety effects of a Collision Countermeasure System (CCS), and update of the Nebraska Department of Roads (NDOR) expressway intersection guidelines. The CCS is an Intelligent Transportation Systems (ITS) traffic control device to warn drivers of conflicting cross-traffic at rural, non-signalized intersections. The goal was that if found effective, the CCS will become part of the intersection designer’s options for expressway intersection design (other options being an interchange, traffic signals, and traffic control signs). …


Restricted-Zone Requirements For Superpave Mixes Made With Local Aggregate Sources, Yong-Rak Kim Mar 2006

Restricted-Zone Requirements For Superpave Mixes Made With Local Aggregate Sources, Yong-Rak Kim

Nebraska Department of Transportation: Research Reports

No abstract provided.


Long-Term Mechanical Behavior Of Yucca Mountain Tuff And Its Variability, Jaak J.K. Daemen, Lumin Ma, Guohua Zhao Mar 2006

Long-Term Mechanical Behavior Of Yucca Mountain Tuff And Its Variability, Jaak J.K. Daemen, Lumin Ma, Guohua Zhao

Publications (YM)

The study of the long term mechanical behavior of Yucca Mountain tuffs is important for several reasons. Long term stability of excavations will affect accessibility (e.g. for inspection purposes), and retrievability. Long term instabilities may induce loading of drip shields and/or emplaced waste, thus affecting drip shield and/or waste package corrosion. Failure of excavations will affect airflow, may affect water flow, and may affect temperature distributions. The long term mechanical behavior of “hard” rocks remains an elusive topic, loaded with uncertainties. A variety of approaches have been used to improve the understanding of this complex subject, but it is doubtful …


Bs News Mar 2006

Bs News

Building Services Engineering

No abstract provided.


Using Value-Focused Thinking To Evaluate The Practicality Of Porous Pavement Parking Areas On Air Force Installations, Christopher D. Bulson Mar 2006

Using Value-Focused Thinking To Evaluate The Practicality Of Porous Pavement Parking Areas On Air Force Installations, Christopher D. Bulson

Theses and Dissertations

Natural runoff processes have been altered by urban development; impervious surfaces (rooftops, highways, parking areas) and their associated storm water systems channel runoff from a vast area into one concentrated outflow. This storm water runoff can cause erosion, flooding, landslides, and significant damage to aquatic ecosystems. Runoff from highways and parking areas has also been known to contain high levels of suspended solids, heavy metals and hydrocarbons. Porous pavements allow infiltration of water through typically impervious surfaces, reducing storm water volumes and acting as a pollutant filtration system. Since there is currently no methodology for Air Force decision-makers to compare …


Stormwater Irrigation Volume Ii: Cyanobacteria Counts With Toxin Concentrations In Stormwater Ponds And After Biofiltration To Reduce Health Risks (2006), Martin Wanielista Feb 2006

Stormwater Irrigation Volume Ii: Cyanobacteria Counts With Toxin Concentrations In Stormwater Ponds And After Biofiltration To Reduce Health Risks (2006), Martin Wanielista

BMP Trains Research and Publications

Algal blooms are a common occurrence in water bodies of all shapes and sizes in the State of Florida as well as all other locations around the world. Cyanobacteria, or blue-green algae, have proven to be of special concern due to proliferation and potential to produce toxins that are harmful to humans, livestock and wildlife. Casual observations of lakes and stormwater ponds in Florida will confirm algal conditions in many. The health risks and the potential for exposure to harmful and possibly fatal toxins associated with these algal blooms are becoming more evident as more nutrients are discharged to our …


Stormwater Irrigation Volume I: Evapotranspiration And Nitrate Reduction After Biofiltration To Reduce Health Risks, Martin Wanielista, Ewoud Hulstein Feb 2006

Stormwater Irrigation Volume I: Evapotranspiration And Nitrate Reduction After Biofiltration To Reduce Health Risks, Martin Wanielista, Ewoud Hulstein

BMP Trains Research and Publications

Irrigation of detained stormwater is an option available for volume and pollution control. Volume control is accomplished when detained waters normally discharged from a detention facility are used instead for irrigation. However, a health risk may result if the nitrate in the irrigation water is not attenuated in the plant and soil matrix. The nitrate level in stormwater ponds is generally much less that the health risk specified as 10 mg/L in Drinking water standards. Nevertheless, the fate of nitrate in the soil plant matrix has not been documented. In addition, there are other potential problems associated with not maintaining …


Ccfss Technical Bulletin Spring 2006, Wei-Wen Yu Center For Cold-Formed Steel Structures Feb 2006

Ccfss Technical Bulletin Spring 2006, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Technical Bulletins (1993 - 2020)

No abstract provided.


Collapse Of The Quebec Bridge, 1907, Cynthia Pearson, Norbert Delatte Feb 2006

Collapse Of The Quebec Bridge, 1907, Cynthia Pearson, Norbert Delatte

Civil and Environmental Engineering Faculty Publications

In the late 19th century, the transportation needs of Quebec led to proposals for bridging the St. Lawrence River. The Quebec Bridge was the longest cantilever structure attempted until that time. In its final design, the clear span was 548.6 m (1,800 ft) long. The bridge project was financially troubled from the beginning. This caused many setbacks in the design and construction. Construction finally began in October 1900. In August 1907, the bridge collapsed suddenly. Seventy five workers were killed in the accident, and there were only 11 survivors from the workers on the span. A distinguished panel was assembled …


Ccfss News Spring 2006, Wei-Wen Yu Center For Cold-Formed Steel Structures Feb 2006

Ccfss News Spring 2006, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Newsletters (1999 - 2008)

No abstract provided.


Value Of Research From 2000-2005: The Kentucky Spr Program For Highway Research, Donald L. Hartman Feb 2006

Value Of Research From 2000-2005: The Kentucky Spr Program For Highway Research, Donald L. Hartman

Kentucky Transportation Center Research Report

The abstracts of the 79 SPR reports completed by KTC researches for 2000-2005 were compiled. Seven projects were selected for value review to demonstrate the various types of benefits that accrue from SPR project research. This review compared objectives with results and described the nature of the benefits (some quantifiable). All of the projects were analyzed to determine: 1) the Kentucky Transportation Cabinet (and FHWA) goals supported and 2) the types of benefits that would reasonably be expected to accrue from implemented results of the research. Most of the 79 projects; results address both improving the performance of the Cabinet …


Behavior Of Filament Winding Fiber Reinforced Polymer Structural Members, Mohamed Soliman Samy Aguib Feb 2006

Behavior Of Filament Winding Fiber Reinforced Polymer Structural Members, Mohamed Soliman Samy Aguib

Archived Theses and Dissertations

Fiber-reinforced polymeric (FRP) composites are being considered for structural members in construction as lighter, more durable alternatives to steel and concrete. Unlike steel and similar isotropic materials where mechanical properties are independent of the applied load directions composites are anisotropic materials by nature. Pultredud FRP structural members that are considered unidirectional members are subjected to premature failure due to discontinuity of fiber in the transverse and through the thickness of the members in a shape of delamination failure. Proposed box-section structural member by utilizing filament-winding process using· woven roving mats instead of roving strands to reorganize the fibers in produced …


Bs News Feb 2006

Bs News

Building Services Engineering

No abstract provided.


Frontal Processes In The Columbia River Plume Area, David A. Jay, Jiayi Pan, Philip M. Orton, Alexander R. Horner-Devine Feb 2006

Frontal Processes In The Columbia River Plume Area, David A. Jay, Jiayi Pan, Philip M. Orton, Alexander R. Horner-Devine

Civil and Environmental Engineering Faculty Publications and Presentations

Information about frontal processes in the Columbia River plume area. Topics include: phenomenology of CR plume fronts, plume responses, upwelling fronts & internal waves: the "Zipper", etc.


Analyzing Dynamic Characteristics Of Internal Solitons Generated At The Columbia River Plume Front With Sar Images, David A. Jay, Jiayi Pan, R. D. Brodeur Feb 2006

Analyzing Dynamic Characteristics Of Internal Solitons Generated At The Columbia River Plume Front With Sar Images, David A. Jay, Jiayi Pan, R. D. Brodeur

Civil and Environmental Engineering Faculty Publications and Presentations

The Columbia River plume transports dissolved and particulate load, phyto- and zooplankton,and larvae across the shelf. It also facilitates primary production and influences food-web structure through its supply of silicate and micronutrients. Small-scale phenomena such as plume fronts and internal waves generated by the plume can greatly affect vertical mixing between the plume and ocean waters. Internal waves that are generated at the front of the river plume and propagate off shoreward [Nash and Moum 2005; Orton and Jay 2005] both cause mixing and transport plume water into the adjacent coastal ocean. We use Synthetic Aperture Radar (SAR) images and …


Prediction Of Service Load Of Concrete Structures After Cracking Using Ultrasonic Technique, Xuezeng Wu Jan 2006

Prediction Of Service Load Of Concrete Structures After Cracking Using Ultrasonic Technique, Xuezeng Wu

Dissertations

The objective of this study is to investigate the cracking behavior of fractured concrete structures and to introduce a new approach to assess their remaining service lives. A novel ultrasonic technique is utilized to detect crack propagation in notched beams of mortar, plain concrete and reinforced concrete. The study showed that crack growth and microcrack zone in cementitious composites can be quantitatively detected by the ultrasound technique.

To predict crack propagation during the fracture process in plain concrete, an effective compliance fracture model is proposed. A large fracture process zone is incorporated in the analytical model by means of an …


Correlating Factors Between Student Participation And Student Learning Via A Service Learning Project In Secondary Education: A Case Study, Shawn V. Jensen Jan 2006

Correlating Factors Between Student Participation And Student Learning Via A Service Learning Project In Secondary Education: A Case Study, Shawn V. Jensen

Theses and Dissertations

In this study a service-learning project was conducted with secondary students in a construction technology based course. Three research questions were considered; (1) does service learning projects help to engage student participation, (2) can students learn the course curriculum while participating in a service learning project, and (3) is there a correlation between student participation and student learning as it pertains to service learning projects? The data was collected through surveys, observations, interviews, and evaluations. The researcher concluded the following from the study; 92% of the students were actively participating in the two week service project, 76% of the students …