Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 30

Full-Text Articles in 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 …


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 …


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 …


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 …


Comparison Of Effectiveness Of Roadway Design Treatments For Transitioning From Rural Areas To Urban Areas Using A Driving Simulator, Candice Hein Aug 2007

Comparison Of Effectiveness Of Roadway Design Treatments For Transitioning From Rural Areas To Urban Areas Using A Driving Simulator, Candice Hein

All Theses

Traffic fatalities are a leading cause of death in the United States. Rural roads are especially hazardous as they account for 60 percent of all traffic fatalities in the United States. Three main reasons for the rural road problems are high speeds, low volumes, and reduced driver awareness. This is particularly problematic where these roads navigate through communities requiring reduced speeds. Drivers who aren't alert and are driving too fast often miss the reduced speed warning signs and often don't slow until after they have entered the community. Therefore, engineers must do something to the design of the roadway environment …


Assessment Of Driver Speeds, Compliance In Rural School Zones: Comparison Of Speed By School Level And Time Of Day, Stuart Day Aug 2007

Assessment Of Driver Speeds, Compliance In Rural School Zones: Comparison Of Speed By School Level And Time Of Day, Stuart Day

All Theses

TThis study analyzed driver's speeds prior to entering school zones as well as the speeds traveling through school zones. A comparison was conducted to determine if drivers complied with school speed zones using only the standard school sign arrangement found in the Manual on Uniform Traffic Control Device. Two rural school zones in Oconee County, South Carolina were analyzed in this study as rural areas tend to have higher speeds and fewer other factors that could contribute to changes in driver behavior. In order to gather data, data collection devices known as Hi-Stars were placed in the roadway on both …


Steer It And Clear It: Effectiveness Of Quick Clearance Legislation, Amy Carol Hamlin Aug 2007

Steer It And Clear It: Effectiveness Of Quick Clearance Legislation, Amy Carol Hamlin

All Theses

Innovative incident management strategies have been sought by transportation professionals to minimize the impacts of incidents on traffic operation and safety. Some current quick clearance strategies such as 'Steer It and Clear It' legislation in South Carolina, which requires driver(s) of involved vehicle(s) in a minor incident to move vehicles promptly from the traveled roadway prior to the arrival of the first responders, can potentially reduce the duration of an incident. The research detailed in this paper endeavored to measure the benefit of the Steer It and Clear It law on a section of I-85 in South Carolina. A simulation …


Achiral And Chiral Analysis Of Polychlorinated Biphenyls (Pcbs) In The Aquatic And Riparian Food Webs In Twelve Mile Creek, South Carolina., Viet Dang Aug 2007

Achiral And Chiral Analysis Of Polychlorinated Biphenyls (Pcbs) In The Aquatic And Riparian Food Webs In Twelve Mile Creek, South Carolina., Viet Dang

All Theses

Polychlorinated biphenyls (PCBs) contamination in the Twelve Mile Creek arm of Lake Hartwell, South Carolina, has been an issue for decades. Lake Hartwell, which is a reservoir located on the border between the states of South Carolina and Georgia, was contaminated with an estimated 440,000 pounds of PCBs. PCBs were released from the Sangamo-Weston capacitor plant located on Town Creek, which feeds into Twelve Mile Creek and ultimately Lake Hartwell. The Twelve Mile Creek tributary connecting the Sangamo-Weston plant to Lake Hartwell has had little attention. Understanding PCBs contamination in the aquatic and riparian food webs of Twelve Mile Creek …


Wind Effects On Monosloped And Sawtooth Roofs, Bo Cui Aug 2007

Wind Effects On Monosloped And Sawtooth Roofs, Bo Cui

All Dissertations

Wind is one of the significant forces of nature that must be considered in the design of buildings. The actual behavior of wind is influenced not only by the surface (or boundary-layer) conditions, but also by the geometry of the building. All sorts of turbulent effects occur, especially at building corners, edges, roof eaves. Some of these effects are accounted for by the wind pressure coefficient. Wind pressure coefficients used in practice have usually been obtained from experimentally by testing models of different type of structures in wind tunnels.
In this study, a series of wind tunnel tests with scale …


Development And Evaluation Of An Enrichment Culture For Bioaugmentation Of The P-Area Chlorinated Ethene Plume At The Savannah River Site, Elizabeth Wood Aug 2007

Development And Evaluation Of An Enrichment Culture For Bioaugmentation Of The P-Area Chlorinated Ethene Plume At The Savannah River Site, Elizabeth Wood

All Theses

The Twin Lakes chlorinated ethene plume at the Department of Energy's
Savannah River Site (SRS) emerges in a wetland in which trichloroethene (TCE) is
completely reduced to ethene and ethane. Novel strains of Dehalococcoides have been
detected from the wetland area. The objectives of this study were 1) to develop an
enrichment culture capable of completely dechlorinating TCE and tetrachloroethene
(PCE) to ethene using samples from the wetland; 2) to evaluate the use of lactate,
emulsified vegetable oil and corn syrup as possible electron donors for biostimulation of
the P-area chlorinated ethene plume at SRS that is not undergoing natural …


Approaches To Mitigate The Impact Of Dissolved Organic Matter On The Adsorption Of Synthetic Organic Contaminants By Activated Carbon, Abhishek Yadav Aug 2007

Approaches To Mitigate The Impact Of Dissolved Organic Matter On The Adsorption Of Synthetic Organic Contaminants By Activated Carbon, Abhishek Yadav

All Theses

The main objective of this study was to conduct a systematic investigation of various approaches to mitigate the competition of dissolved organic matter (DOM) on the adsorption of synthetic organic contaminants (SOCs) by activated carbons. TCE and atrazine were selected as the target SOCs because they are known to adsorb in different pore size regions. TCE adsorbs in the primary micropore region (i.e., <10 ) which is inaccessible to the majority of the DOM components, while atrazine adsorbs in the secondary micropore region (i.e., 10-20 ) which is partially accessible to some DOM components. The adsorbents used in this study consisted of four activated carbons (OLC, CRC, F400He, and HD4000ST) and one activated carbon fiber (ACF: ACF10). All sorbents were basic and hydrophobic in nature and represented a set of activated carbons with gradually widening pore size distribution, from the extremely microporous carbons (ACF10 and OLC) to carbons with some amount of mesopores (CRC and F400He) and finally a predominantly mesoporous (HD4000ST) carbon.
Isotherms were performed as single solute and after preloading with a dissolved organic matter (5 mg DOC/L and 20 mg DOC/L) for both TCE and atrazine and using the five activated carbons. Single solute isotherm results showed …


Evaluation Of Lithium Based Deicing Chemicals For Mitigating Asr In Concrete Pavement, Senthil Soundarapandian Aug 2007

Evaluation Of Lithium Based Deicing Chemicals For Mitigating Asr In Concrete Pavement, Senthil Soundarapandian

All Dissertations

Deicing and anti-icing chemicals such as alkali-acetate and alkali-formate based formulations are increasingly being used on airfield pavements. Among these new deicers, potassium acetate-based formulations are widely used due to their environmentally friendly nature and effectiveness in melting and undercutting ice at low temperatures. Recent research on premature deterioration of airfield pavements due to alkali-silica reaction (ASR) has indicated that alkali-acetate and alkali-formate deicers such as potassium acetate and sodium formate may have been responsible for the observed distress. In an effort to develop a deicing chemical that is benign to concrete from an ASR standpoint, a new deicing formulation …


Characterization Of Recycled Aged Crm Binders, Soon-Jae Lee Aug 2007

Characterization Of Recycled Aged Crm Binders, Soon-Jae Lee

All Dissertations

The incorporation of conventional reclaimed asphalt pavement (RAP) in hot-mix asphalt (HMA) pavements has become routine in many states around the United States and many other countries all over the world. In addition, the recycling of crumb rubber modified (CRM) materials has been an area of interest since CRM was first used in asphalt paving materials over 40 years ago. Previous research on the recycling of rubberized asphalt concrete (RAC) materials have been limited and focused mainly on the mixture properties at the location of in-field paving. However, for the long-term performance characterizations, it is needed to investigate the aging …


Corrosion Effects On Tension Stiffening Behavior Of Reinforced Concrete, M. A. Shayanfar, M. Ghalehnovi, Amir Safiey Aug 2007

Corrosion Effects On Tension Stiffening Behavior Of Reinforced Concrete, M. A. Shayanfar, M. Ghalehnovi, Amir Safiey

Publications

The investigation of corrosion effects on the tensile behavior of reinforced concrete (RC) members is very important in region prone to high corrosion conditions. In this article, an experimental study concerning corrosion effects on tensile behavior of RC members is presented. For this purpose, a comprehensive experimental program including 58 cylindrical reinforced concrete specimens under various levels of corrosion is conducted. Some of the specimens (44) are located in large tub containing water and salt (5% salt solution); an electrical supplier has been utilized for the accelerated corrosion program. Afterwards, the tensile behavior of the specimens was studied by means …


Numerical And Physical Modeling Of Turbulent Shear Flows, John Raiford May 2007

Numerical And Physical Modeling Of Turbulent Shear Flows, John Raiford

All Dissertations

This dissertation is an evaluation of popular turbulence schemes; both three dimensional and depth-averaged, and also includes an experimental study on shallow near bed jets. The three dimensional and RNG turbulent closure schemes are evaluated for free and bounded shear flows. For free shear flows (circular and plane turbulent jets), the scheme with standard coefficient performs equally well and in some cases better than the renormalized group scheme in predicting growth rate, decay of centerline velocity and longitudinal velocity profiles. For turbulent kinetic energy across the jet, the inner region is better predicted by the RNG scheme.
The second case …


Evaluating The Impacts Of Accelerated Incident Clearance Tools And Strategies By Harnessing The Power Of Microscopic Traffic Simulation , Ryan Fries May 2007

Evaluating The Impacts Of Accelerated Incident Clearance Tools And Strategies By Harnessing The Power Of Microscopic Traffic Simulation , Ryan Fries

All Dissertations

Traffic incidents cause Americans delay, waste fuel, cause injuries, and create toxic emissions. Transportation professionals have implemented a variety of tools to manage these impacts and researchers have studied their effectiveness, illustrating a wide range between different tools and locations. To improve this state of knowledge, this dissertation sought to 1) identify prominent and effective incident management strategies, 2) model six selected incident management strategies within five highway corridors in South Carolina, and 3) apply benefit-cost analysis to evaluate the impact of various combinations of these strategies.
To meet these objectives, the author evaluated published literature of the selected strategies, …


Wall And Ground Movements In A Braced Excavation In Clays And Serviceability Reliability Of Adjacent Buildings, Cheng Liang Hsiao May 2007

Wall And Ground Movements In A Braced Excavation In Clays And Serviceability Reliability Of Adjacent Buildings, Cheng Liang Hsiao

All Dissertations

The goal of this dissertation research is to establish an improved procedure for evaluating the excavation-induced ground settlement and building serviceability. This research covers several closely related topics. Firstly, a simplified small strain soil model developed by Hsieh et al. (2003), called the Modified Pseudo Plasticity (MPP) model, is evaluated for its capability and performance in the prediction of the excavation-induced ground deformation behavior using Finite Element Method (FEM). Secondly, for the development of the envisioned empirical models for estimating the excavation-induced wall and ground responses, a database of excavation case histories are compiled. To complement the database of excavation …


Evaluation Of Different Contra-Flow Strategies For Hurricane Evacuation In Charleston, South Carolina, Liz Stephen May 2007

Evaluation Of Different Contra-Flow Strategies For Hurricane Evacuation In Charleston, South Carolina, Liz Stephen

All Theses

The number of category four and five hurricanes has nearly doubled over the past decade. Charleston, the second most populous city in South Carolina, is located on a very low peninsula, making it susceptible to floods during hurricanes and storm surges. In the event of a hurricane, the population at-risk must be evacuated to safety as quickly as possible. The Interstate system is the primary mode to evacuate at-risk population out of Charleston. Effective traffic management strategies are needed to manage the significant increase in demand on highways during the evacuation and contra-flowing traffic has been applied as a strategy …


Characterization Of The Ibc Technologies Superlig¨ 620 Solid Phase Extraction Resin With Applications For Automated Process Monitoring, John Clements May 2007

Characterization Of The Ibc Technologies Superlig¨ 620 Solid Phase Extraction Resin With Applications For Automated Process Monitoring, John Clements

All Theses

Characterization of the IBC Advanced Technologies SuperLig¨ 620 solid phase extraction resin was performed in order to develop an automated strontium-90 process monitor. The main focus was on strontium separation from barium, with the goal of developing an automated separation process for strontium-90 in Hanford high-level tank wastes. High-level waste tanks contain significant cesium-137 activities, of which barium daughters are of great concern as interferences to strontium quantification. A number of complexants were studied in a series of batch distribution coefficient experiments, as SuperLig¨ 620 was not previously known to elute strontium in typical mineral acids. The optimal separation was …


Information Flow To Support Front End Planning, Ryan George May 2007

Information Flow To Support Front End Planning, Ryan George

All Dissertations

Previous research has demonstrated the value of front end planning as it impacts project performance. This dissertation summarizes the findings of a research project which examined ways to improve information flow through the front end planning process. The front end planning process was carefully diagrammed as consisting of 33 distinct information flow activities, each with its own information flow entities and interactions. Fifty-one questionnaire survey forms were analyzed to obtain data for the 33 information flow activities that included activity duration, resources expended, and other supplemental insights such as the extent of information availability. The 51 projects were then grouped …


A Lean Modeling Protocol For Evaluating Green Project Delivery, Leidy E. Klotz, Michael Horman, Mark Bodenschatz Apr 2007

A Lean Modeling Protocol For Evaluating Green Project Delivery, Leidy E. Klotz, Michael Horman, Mark Bodenschatz

Publications

The first vital step to leaning an operation is to model or map the processes used to deliver value in that operation. This allows the requisite understanding of where waste and non value-adding activity exists, and provides the foundation for improvement. Current protocols for modeling operations present the basic tenets for lean mapping, but tend to be based in manufacturing language, and are not easily adapted to capital facilities projects. “Green” or “sustainable” capital projects delivered using current project delivery systems seem to be laden with hidden waste. These projects tend to be more challenging to deliver due increased levels …


Application Of Classical Versus Bayesian Statistical Methods To On-Line Radiological Monitoring, Amy Attardo Jan 2007

Application Of Classical Versus Bayesian Statistical Methods To On-Line Radiological Monitoring, Amy Attardo

All Theses

The on-line monitoring for illicit radioactive material with a minimum number of false detections is a critical need for homeland security. The primary objectives of this work were to apply both Bayesian and classical statistical process control chart techniques to the on-line monitoring of radiological data and to then compare the Type I and Type II error incidence rates. Two versions of the cumulative sum (CUSUM) and Shiryayev-Roberts (S-R) procedures known as total reset and alarm reset methods were developed. The best method in terms of Type I errors was the S-R total reset method. In terms of Type II …