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2007

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Articles 1 - 30 of 726

Full-Text Articles in Civil and Environmental Engineering

Metalloporphyrin Catalyzed Degradation Of Pce: Effects Of Reductants, Buffers And Cosolvent Concentration, Sowmya Suryanarayanan Dec 2007

Metalloporphyrin Catalyzed Degradation Of Pce: Effects Of Reductants, Buffers And Cosolvent Concentration, Sowmya Suryanarayanan

All Theses

Reductive dechlorination of chlorinated organic contaminants using metalloporphyrins as catalysts may be an effective approach to treat widespread contamination. However, most previous studies have examined water-soluble rather than insoluble metalloporphyrins despite the fact that the latter category makes up the largest fraction found in nature. Recent studies have shown that addition of different cosolvents to water can activate otherwise non-reactive metalloporphyrin catalysts and facilitate the reduction of tetrachloroethylene (PCE), presumably by the mere process of making the otherwise insoluble metalloporphyrins dissolve in solution. Therefore, solubility has been advanced as a key factor in the ability of metalloporphyrins to catalyze organic …


Evaluation Of A Computer Vision Traffic Surveillance System, Robert Graham Dec 2007

Evaluation Of A Computer Vision Traffic Surveillance System, Robert Graham

All Theses

This thesis presents an evaluation of the accuracy of a novel computer vision traffic sensor - developed by the Clemson University Electrical and Civil Engineering Departments - capable of collecting a variety of traffic parameters. More specific, the thesis examines how the camera height and distance from the travel way affects the accuracy. The details of the quantitative and qualitative evaluations used to validate the system are provided. The parameters chosen to evaluate were volume, vehicle classification, and speed. Experimental results of cameras mounted at heights of 20 and 30 feet and a lateral distance of 10 and 20 feet …


Bacterial Auto-Aggregation And Co-Aggregation In Activated Sludge, Fei Chen Dec 2007

Bacterial Auto-Aggregation And Co-Aggregation In Activated Sludge, Fei Chen

All Theses

Microbial auto-aggregation and co-aggregation, leading to biofilm or floc formation, widely occur in natural systems. This study was conducted to investigate the extent of bacterial auto-aggregation and co-aggregation in activated sludge and their contributions in activated sludge floc formation. In this study, an activated sludge sample was separated into a supernatant part (planktonic community) and a sediment part (floc community) by centrifugation at 650_g for 2 minutes. 197 strains were isolated from both communities. These isolates belong to 18 phylotypes based on molecular identifications. Similar phylogenetic distributions of these isolates were observed in planktonic and floc communities, suggesting a similar …


Nirt: Developing A Nanoscale Sensing Device For Measuring The Supply Of Iron To Phytoplankton In Marine Systems, Mark L. Wells, Karen Orcutt, D. Whitney King, Carl Tripp Dec 2007

Nirt: Developing A Nanoscale Sensing Device For Measuring The Supply Of Iron To Phytoplankton In Marine Systems, Mark L. Wells, Karen Orcutt, D. Whitney King, Carl Tripp

University of Maine Office of Research Administration: Grant Reports

There is increasing evidence that Fe has a singularly unique role in marine ecosystems, both regulating total phytoplankton production in high nitrate, low chlorophyll regions of the world, and influencing the predominant composition of the phytoplankton assemblages found in others. It is remarkable then that there is no agreement about how to define biologically available Fe, in contrast to the macronutrients nitrogen, phosphorous or silicon. Current attempts to attain predictive insights to how ocean ecosystems will influence the magnitude of climate change are blocked in large part by this question, along with an extreme shortage of data on Fe distributions …


Laboratory Evaluation Of Microbial Aggregation In Activated Sludge, Xiaoling Liu Dec 2007

Laboratory Evaluation Of Microbial Aggregation In Activated Sludge, Xiaoling Liu

All Theses

Microbial aggregation was investigated in this study using the activated sludge process as a model system, the performance of which is highly dependent on effective bioaggregation. This research includes two experiments. First, four laboratory-scale activated sludge sequencing batch reactors (SBRs) were constructed in order to evaluate the effect of solids retention time (SRT) on microbial aggregation. These SBRs were operated at SRT of 4, 8, 16, and 32 days, respectively, fed with a protein-based synthetic wastewater, and monitored over a period of 268 days for performance and sludge settling characteristics including soluble COD in the effluent (sCOD), sludge volume index …


Cosolvent Effects On The Reductive Dechlorination Of Tetrachloroethylene Catalyzed By Iron Tetraphenyl Porphyrin Chloride, Lavanya Ramasubramanian Dec 2007

Cosolvent Effects On The Reductive Dechlorination Of Tetrachloroethylene Catalyzed By Iron Tetraphenyl Porphyrin Chloride, Lavanya Ramasubramanian

All Theses

Abiotic electron transfer mediated reductive dechlorination reactions have been studied extensively in the past decade. Porphyrins and metalloporphyrins are common electron transfer mediators used. Past studies have shown that some metalloporphyrins play a key role in increasing the rate of reaction in the presence of cosolvents. There have also been suggestions that organic cosolvents enhance the rate of reduction by increasing the solubility of metalloporphyrins.
The primary objective of this project was to examine the effect of cosolvents on the metalloporphyrin-catalyzed reductive dechlorination of tetrachloroethylene (PCE). Subsequently, experiments were also conducted to test the hypothesis that metalloporphyrin solubility is linked …


Assessing Asr Potential Of Hardened Concrete And The Use Of Rice Husk Ash To Mitigate Asr, David Wingard Dec 2007

Assessing Asr Potential Of Hardened Concrete And The Use Of Rice Husk Ash To Mitigate Asr, David Wingard

All Theses

This two part research study was created to first develop a new process using existing test methods to determine the Alkali-Silica Reaction (ASR) potential of hardened concrete that is exposed to external alkalis and secondly to determine the ASR mitigation potential of using rice husk ash (RHA) as a supplementary cementitious material (SCM). The first part of the research study was completed by using a new aggregate extraction procedure that uses a combination of hydrochloric acid treatments and abrasion to remove the cement paste from the aggregate. This extracted aggregate was then crushed down to the specified sizes and used …


Seismic Fragility Curves For A Typical Highway Bridge In Charleston, Sc Considering Soil-Structure Interaction And Liquefaction Effects, Matthew Bowers Dec 2007

Seismic Fragility Curves For A Typical Highway Bridge In Charleston, Sc Considering Soil-Structure Interaction And Liquefaction Effects, Matthew Bowers

All Theses

Evidence from historical earthquakes suggests that the vulnerability of highway bridges is significantly affected by large permanent ground deformations caused by liquefaction as well as soil-structure interaction (SSI). The vulnerability of a typical multi-span simply-supported (MSSS) concrete girder bridge found in Charleston, South Carolina, is evaluated with consideration for liquefaction and SSI effects. In general, existing bridges in this region were not originally designed with consideration for seismic events or liquefaction of underlying soils. Fragility curves that represent the probability of exceeding predefined performance levels of damage given an earthquake of a particular intensity are used to evaluate the effects …


Investigation Into Mitigation Of Alkali-Silica Reaction Using Selected Scms In Presence Of Potassium Acetate Deicer, Jigar Desai Dec 2007

Investigation Into Mitigation Of Alkali-Silica Reaction Using Selected Scms In Presence Of Potassium Acetate Deicer, Jigar Desai

All Dissertations

Alkali-silica reaction (ASR) is one of the most recognized durability problems in concrete leading to premature deterioration of different types of concrete structures. Recent investigation into premature deterioration of airfield concrete pavements indicated the aggressive effects of alkali-acetate and alkali-formate based deicers on concrete containing marginal aggregates, in particular on their potential to induce ASR.. This dissertation presents the results and analysis from a research study conducted to evaluate the effectiveness of selected supplementary cementitious materials-SCMs (fly ash and slag) as ASR mitigation measures in presence of potassium acetate based deicer.
Five aggregates that encompass a range of mineralogies and …


Sediment Transport Upstream Of Orifices, David Powell Dec 2007

Sediment Transport Upstream Of Orifices, David Powell

All Dissertations

Sediment transport upstream of orifices has not been studied outside the realm of the restoration of reservoir storage capacity. This experimental study used a large basin with a circular orifice outlet and a movable sand bed leveled with the invert of the orifice. Three sizes of non-cohesive, uniform sand were used with d50 values of 0.29mm, 0.72mm, and 0.89mm. Bed profiles at equilibrium scour conditions were measured for three different head levels for each sediment size. The maximum scour depth, length, and scour width were related to the particle size and the available head. The longitudinal and lateral extents …


Causey, Robert Lewis, B. 1927 (Sc 1316), Manuscripts & Folklife Archives Dec 2007

Causey, Robert Lewis, B. 1927 (Sc 1316), Manuscripts & Folklife Archives

MSS Finding Aids

Finding aid only for Manuscripts Small Collection 1316. Comments written by Causey, Bowling Green, Kentucky, concerning the proposed industrial Trimodal Transpark that would be located near Smiths Grove, Kentucky, if approved.


Tubería Petrolera Recurso Para La Construcción De Puentes, Diego Armando Leal Vargas, Wilmar Armando Jiménez Marulanda, Anderson Salvador Bernal Tello Dec 2007

Tubería Petrolera Recurso Para La Construcción De Puentes, Diego Armando Leal Vargas, Wilmar Armando Jiménez Marulanda, Anderson Salvador Bernal Tello

Ingeniería Civil

No abstract provided.


A Pilot Study On The Effects Of Temperature On The Material Properties Of Prestressed Concrete And The Use Of Thermogravimetric Analysis In The Assessment Of Heat-Affected Concrete, Kacie Caple Dec 2007

A Pilot Study On The Effects Of Temperature On The Material Properties Of Prestressed Concrete And The Use Of Thermogravimetric Analysis In The Assessment Of Heat-Affected Concrete, Kacie Caple

All Theses

An understanding of the material property changes in building materials due to exposure to a fire is needed for accurate damage assessment of a structure. Discussion pertaining to material property changes and the bond between concrete and prestressing steel following elevated temperature exposures is presented. Evaluation of the use of thermogravimetric analysis (TGA) as a post-fire analysis tool to determine the maximum temperature exposure of concrete is also included.
Heated concrete cylinders were tested to determine the compressive strength and modulus of elasticity changes of concrete. Heated steel prestressing strands were tested in tension to determine changes in the ultimate …


Experimental And Analytical Application Of The Hodd Method For The Detection Of Damage, Jacob Merkley Dec 2007

Experimental And Analytical Application Of The Hodd Method For The Detection Of Damage, Jacob Merkley

All Theses

Detecting damage location and severity in civil engineering structures has become an important research topic in the past several decades. Various non-destructive damage identification methods using dynamic properties from ambient and forced vibration have been developed. Researchers have shown that higher order derivatives of mode shapes of the 2nd and 4th order can be effective in detecting damage in civil engineering structures. Furthermore, these higher order derivatives are sensitive to small changes in global stiffness facilitating the detection of small degrees of damage.
In this study a modal analysis is performed on analytical and experimental simply supported beams using the …


Energy Efficiency In Cold-Weather High-End Custom Homes, Joseph R. Kearl Dec 2007

Energy Efficiency In Cold-Weather High-End Custom Homes, Joseph R. Kearl

Theses and Dissertations

Nationally, there is increasing interest in energy efficient homes due to growing energy costs and increased awareness. However, many builders haven't yet incorporated energy saving products and practices into homes. Many builders don't have the resources to evaluate available options and prefer to rely on the experiences of other builders. The purpose of this study was to create energy efficiency benchmarks for cold-weather, high-end custom homes and evaluate current building practices. A list of energy-efficient products and practices was created through a review of relevant literature. A group of expert builders was formed into a committee to help determine energy …


College Of Engineering Senior Design Competition Fall 2007, University Of Nevada, Las Vegas Dec 2007

College Of Engineering Senior Design Competition Fall 2007, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge.

The senior design competition helps to focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects …


Sensitivity Of Half-Cell Potential Measurements To Properties Of Concrete Bridge Decks, Thad Marshall Pinkerton Dec 2007

Sensitivity Of Half-Cell Potential Measurements To Properties Of Concrete Bridge Decks, Thad Marshall Pinkerton

Theses and Dissertations

Half-cell potential testing has been recommended as a non-destructive method for assessing the corrosion potential of reinforcing steel in concrete bridge decks. The technique is particularly useful because it can be utilized to evaluate the probability of corrosion before damage is evident at the surface of a bridge deck. The specific objective of this research was to quantify the effects of age, chloride concentration, concrete cover thickness, spatial position, temperature, and presence or condition of epoxy coating on half-cell potential measurements of concrete bridge decks typical of those in Utah. The laboratory testing associated with this research followed a full-factorial …


Buffer Law And Transitional Roughness Effect In Turbulent Open-Channel Flows, Junke Guo, Pierre Y. Julien Dec 2007

Buffer Law And Transitional Roughness Effect In Turbulent Open-Channel Flows, Junke Guo, Pierre Y. Julien

Department of Civil and Environmental Engineering: Faculty Publications

A novel and complete velocity profile law is presented for turbulent open channel flows. The law embeds the linear law in the viscous sublayer; the quartic law due to turbulent bursting that must satisfy instantaneous mass conservation, the modified log-wake law in the outer region and the effects of wall roughness. Specifically, an arctangent law smoothly connects the linear law with the log law of the wall. Combining the arctangent law with the modified log-wake law, a continuous velocity profile is proposed for smooth boundary conditions. A complete velocity profile is obtained after subtracting a new roughness function. Finally, the …


Commissioners Report On The Shoals In The Ohio River (Sc 1545), Manuscripts & Folklife Archives Dec 2007

Commissioners Report On The Shoals In The Ohio River (Sc 1545), Manuscripts & Folklife Archives

MSS Finding Aids

Finding aid and full-text scan (Click on "Additional Files" below) for Manuscripts Small Collection 1545. Photocopy (made in 1970) of handwritten Ohio River survey done in 1819 related to river navigation in Ohio, Kentucky, Virginia, and Indiana. It includes many hand-drawn maps. There is a large, undated map in a pocket on inside back cover.


Environmental Sustainability Asessment In Iran’S Southpars Special Economic Energy Zone, Omidreza Saadatian Dec 2007

Environmental Sustainability Asessment In Iran’S Southpars Special Economic Energy Zone, Omidreza Saadatian


No abstract provided.


Mexico Engineering Study Abroad: Assessing The Effectiveness Of International Experiences On Teaching Global Engineering Skills, Joshua Benjamin Draper Dec 2007

Mexico Engineering Study Abroad: Assessing The Effectiveness Of International Experiences On Teaching Global Engineering Skills, Joshua Benjamin Draper

Theses and Dissertations

Globalization is a rapidly increasing trend in many industries, including civil engineering. This paper defines the skills engineers will need in an increasingly international industry. It also describes an engineering study abroad program designed to teach some of those skills to students and presents a survey used as an assessment tool to evaluate the effectiveness of the program. The program, called Mexico Engineering Study Abroad (MESA), is taught at Brigham Young University (BYU) in Provo, UT. MESA is a project-based extended field trip format class that couples hydrologic modeling with cultural awareness as students work together with Mexican students on …


Dry Stacked Surface Bonded Masonry - Structural Testing And Evaluation, Eric B. Murray Dec 2007

Dry Stacked Surface Bonded Masonry - Structural Testing And Evaluation, Eric B. Murray

Theses and Dissertations

The ENDURA block system is a dry-stack surface-bonded masonry system. Typical masonry construction uses thin-set mortar in the bed joints to provide a bearing surface for the blocks while the ENDURA system typically relies on shims and a surface bonding coat to ensure that the wall is level and plumb and to provide stability. Typical ENDURA block walls are built with the reinforcement placed eccentrically in the walls. Testing was performed on ten walls in order to determine axial capacity. The walls were ten feet high by eight feet wide. Each of the walls was built using a different configuration …


Time And Frequency Domain Analyses Of Hydrologic And Stream Water Quality Data, Shesh Raj Koirala Dec 2007

Time And Frequency Domain Analyses Of Hydrologic And Stream Water Quality Data, Shesh Raj Koirala

Doctoral Dissertations

The issue of scaling of deterministic properties at various domain levels has become an area of interest for active research. Interpretation of observational data, and similarly hydrologic simulation, require an understanding of how certain deterministic modeling parameters scale from the smaller to larger domains spatially and temporally. Novel approaches to better understand scaling behavior in hydrologic systems and that will result in improved deterministic modeling are necessary to advance the state-of-the-science in hydrologic transport processes, particularly in the areas of microbial concentration and inorganic chemical constituent dynamics. Two primary objectives of this research were i) to determine the statistical relationship …


Evaluation Of Impacts On Delay, Cycle-Length Optimization, Control Types, And Peak-Hour Factor With The Randomness Of Traffic, Jan-Mou Li Dec 2007

Evaluation Of Impacts On Delay, Cycle-Length Optimization, Control Types, And Peak-Hour Factor With The Randomness Of Traffic, Jan-Mou Li

Doctoral Dissertations

Some basic concepts about traffic which are correct in theory may be misinterpreted in practice. Such misinterpretations may lead to a different direction from the ideal operation. This four-part dissertation is designated to examine fundamental concepts in traffic operation, and to validate the impact of randomness on control delays, cycle-length optimization, control types, and the peak-hour factor.

Control delays experienced by drivers is a critical performance measure on interrupted-flow traffic which involves movements at slower speeds and stops on intersection approaches, as vehicles move up in the queue or slow down upstream of an intersection. Since the basic term of …


Evaluation Of Current Nonlinear Static Procedures For Concrete Buildings Using Recorded Strong-Motion Data, Rakesh K. Goel, Charles Chadwell Dec 2007

Evaluation Of Current Nonlinear Static Procedures For Concrete Buildings Using Recorded Strong-Motion Data, Rakesh K. Goel, Charles Chadwell

Civil and Environmental Engineering

This study evaluates current Nonlinear Static Procedures (NSPs) specified in the FEMA356, ASCE-41, ATC-40, and FEMA-440 documents using strong-motion data from reinforced-concrete buildings. For this purpose, three-dimensional computer models of five reinforced concrete buildings – Imperial County Services Building, Sherman Oaks Commercial Building, North Hollywood Hotel, Watsonville Commercial Building, and Santa Barbara Office Building – are developed. When appropriate, springs at the building’s base are included to account for the soil-structure interaction effects. These buildings are selected because they were strongly shaken, several deformed beyond their linear-elastic range, during past earthquakes and their recorded motions are available. The recorded motions …


Burrowing In Marine Muds By Crack Propagation: Kinematics And Forces, Sanjay Raja Arwade, Kelly M. Dorgan, Peter A. Jumars Dec 2007

Burrowing In Marine Muds By Crack Propagation: Kinematics And Forces, Sanjay Raja Arwade, Kelly M. Dorgan, Peter A. Jumars

Sanjay Raja Arwade

The polychaete Nereis virens burrows through muddy sediments by exerting dorsoventral forces against the walls of its tongue-depressor-shaped burrow to extend an oblate hemispheroidal crack. Stress is concentrated at the crack tip, which extends when the stress intensity factor (KI) exceeds the critical stress intensity factor (KIc). Relevant forces were measured in gelatin, an analog for elastic muds, by photoelastic stress analysis, and were 0.015±0.001 N (mean ± s.d.; N=5). Measured elastic moduli (E) for gelatin and sediment were used in finite element models to convert the forces in gelatin to those required in muds to maintain the same body …


Evaluation Of The Role Of Driver’S Knowledge Of Who Has The Right-Of-Way Contributes To Interstate On-Ramp Crashes, Deogratias Eustace, Vamsi Krishna Indupuru Dec 2007

Evaluation Of The Role Of Driver’S Knowledge Of Who Has The Right-Of-Way Contributes To Interstate On-Ramp Crashes, Deogratias Eustace, Vamsi Krishna Indupuru

Civil and Environmental Engineering and Engineering Mechanics Faculty Publications

The knowledge of drivers on who has the right-of-way between the one on mainline lanes of a freeway and the one entering the freeway through on-ramp junction lane was evaluated. In addition, drivers’ opinions on how to make the on-ramp junctions safer were collected. A survey instrument with 21 items requesting drivers’ information in regard with demographics, freeway driving experience, knowledge of right-of-way and merging practices was used for data collection. The results show that crashes are relatively rare events and for some reasons, most of them never happen but result into near misses, which can not be reported and …


2006 Summary Of Highway Revenues, Distributions, & Expenses For Indiana Counties, Cities, & Towns, Indiana Ltap Dec 2007

2006 Summary Of Highway Revenues, Distributions, & Expenses For Indiana Counties, Cities, & Towns, Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Publications

This report provides information on revenues, distributions, and expenses of state and local governments for highway, road, and street work. Since the Motor Vehicle Highway (MVH) and Local Road and Street (LRS) Accounts are the principal source of funds for local road or street construction and maintenance operations, this summary may be used to see the trends in income sources and in the expenses charged to the funds prior to their being distributed to the highway, road, and street agencies.


Rideability Issues For Asphalt And Concrete Specification Modifications, Brad Rister, Clark Graves Dec 2007

Rideability Issues For Asphalt And Concrete Specification Modifications, Brad Rister, Clark Graves

Kentucky Transportation Center Research Report

Concerns have been raised regarding the differences between the incentive/disincentive determination procedures as well as the pay adjustments for rideability between asphalt and concrete projects. This report will attempt to do the following:

  1. Address the differences between concrete and asphalt rideability specifications by looking at Kentucky’s historical rideability specifications and the specifications of peer states.
  2. Review the necessity to revise current specifications based on historical rideability data, peer states rideability specifications, technological advancements in placement of roadway materials, and technological advancements in measuring rideability after construction.
  3. Evaluate the monetary impact of a revised rideability specification on the latest year’s data. …


Performance Based Contracting And Improving The Current Contracting Process, Troy Berkland Dec 2007

Performance Based Contracting And Improving The Current Contracting Process, Troy Berkland

All Theses

The primary objective of the research described in this report was to suggest improvements to the maintenance contracting process currently utilized by the South Carolina Department of Transportation (SCDOT). A secondary research objective was to examine to what extent SCDOT could migrate more toward performance based, as opposed to method based, highway maintenance specifications.
A comprehensive literature review indicated some states had successfully implemented performance based specifications for a wide range of maintenance activities whereas others had not. Some states have adopted performance based specifications as part of a comprehensive asset management program whereby the contractor typically performs all routine …