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2007

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Articles 91 - 120 of 340

Full-Text Articles in Civil Engineering

Kinetic Model For Triglyceride Hydrolysis Using Lipase:Review, Heri Hermansyah, A. Wijanarko, Dianursanti Dianursanti, Misri Gozan, Praswasti P. D.K Wulan, Rita Arbianti, Roekmijati W. Soemantojo, Tania Surya Utami, Yuliusman Yuliusman, Momoji Kubo, Naomi Shibasaki Kitakawa, Toshiy Yonemoto Apr 2007

Kinetic Model For Triglyceride Hydrolysis Using Lipase:Review, Heri Hermansyah, A. Wijanarko, Dianursanti Dianursanti, Misri Gozan, Praswasti P. D.K Wulan, Rita Arbianti, Roekmijati W. Soemantojo, Tania Surya Utami, Yuliusman Yuliusman, Momoji Kubo, Naomi Shibasaki Kitakawa, Toshiy Yonemoto

Makara Journal of Technology

Triglyceride hydrolysis using lipase has been proposed as a novel method to produce raw materials in food and cosmetic industries such as diacylglycerol, monoacylglycerol, glycerol and fatty acid. In order to design a reactor for utilizing this reaction on industrial scale, constructing a kinetic model is important. Since the substrates are oil and water, the hydrolysis takes place at oil-water interface. Furthermore, the triglyceride has three ester bonds, so that the hydrolysis stepwise proceeds. Thus, the reaction mechanism is very complicated. The difference between the interfacial and bulk concentrations of the enzyme, substrates and products, and the interfacial enzymatic reaction …


Sulfonation Of Cptfe Film Grafted Styrene For Proton Exchange Membrane Fuel Cell, Yohan Yohan Apr 2007

Sulfonation Of Cptfe Film Grafted Styrene For Proton Exchange Membrane Fuel Cell, Yohan Yohan

Makara Journal of Technology

Sulfonation of cPTFE Film grafted Styrene for Proton Exchange Membrane Fuel Cell. Sulfonation of γ-ray iradiated and styrene-grafted crosslinked polytetrafluoroethylene film (cPTFE-g-S film) have been done. The aim of the research is to make hydropyl membrane as proton exchange membrane fuel cell. Sulfonation was prepared with chlorosulfonic acid in chloroethane under various conditions. The impact of the percent of grafting, the concentration of chlorosulfonic acid, the reaction time,and the reaction temperature on the properties of sulfonated film is examinated. The results show that sulfonation of surface-grafted films is incomplete at room temperature. The increasing of concentration of chlorosulfonic acid and …


Evaluation Of Unknown Foundations, Ronald W. Florkowski Mar 2007

Evaluation Of Unknown Foundations, Ronald W. Florkowski

USF Tampa Graduate Theses and Dissertations

In recent years, bridge foundations have been in the spotlight throughout the nation. Bridges built over running water are susceptible to erosion or scour around their foundations. The reduction in load capacity to piers and abutments pose a safety risk to highway motorists. It has become necessary for engineers to examine and monitor these "scour critical" bridges. The difficulty arises with subsurface foundations of which very little is known about their construction. Hence, the methods applied to analyzing "Unknown Foundations" have become a necessary topic of research.

This thesis explores a method to determine foundation lengths. Similar to Sonic Echo …


Effect Of Backwashing On Perchlorate Removal In Fixed Bed Biofilm Reactors, Young Chul Choi, Xu Li, Lutgarde Raskin, Eberhard Morgenroth Mar 2007

Effect Of Backwashing On Perchlorate Removal In Fixed Bed Biofilm Reactors, Young Chul Choi, Xu Li, Lutgarde Raskin, Eberhard Morgenroth

Department of Civil and Environmental Engineering: Faculty Publications

The influence of backwashing on biological perchlorate reduction was evaluated in two laboratory scale fixed bed biofilm reactors using 1- or 3-mm glass beads as support media. Influent perchlorate concentrations were 50 μg/L and acetate was added as the electron donor at a concentration of 2 mg C/L. Perchlorate removal was evaluated at various influent dissolved oxygen (DO) concentrations. Complete perchlorate removal was achieved with an influent DO concentration of 1 mg/L resulting in bulk phase DO concentrations below the detection limit of 0.01 mg/L. The influence of increasing influent DO concentrations for 12 h periods was evaluated before and …


Bs News Mar 2007

Bs News

Building Services Engineering

No abstract provided.


Bs News Feb 2007

Bs News

Building Services Engineering

No abstract provided.


Evaluation Of An Existing Steel Post Alternative For The Thrie Beam Bullnose Guardrail System, Robert W. Bielenberg, Ronald K. Faller, John R. Rohde, John D. Reid Jan 2007

Evaluation Of An Existing Steel Post Alternative For The Thrie Beam Bullnose Guardrail System, Robert W. Bielenberg, Ronald K. Faller, John R. Rohde, John D. Reid

Mid-America Transportation Center: Final Reports and Technical Briefs

Recently, the Minnesota Department of Transportation (MnDOT) funded a research project through the Midwest States Regional Pooled Fund to evaluate an existing steel post alternative for the thrie beam bullnose barrier system previously developed at the Midwest Roadside Safety Facility (MwRSF). MnDOT had an interest in the replacement of the wooden breakaway posts used in the current bullnose system with proprietary breakaway steel posts. The research project consisted of evaluation of current breakaway steel post designs, investigation and selection of a candidate post design, and full-scale testing of the bullnose system with a steel post alternative. The full-scale testing was …


Water Quality Modelling In Dublin From Bray To Balbriggan Gdsds/75407/130, Aodh Dowley, Zeinab Bedri Jan 2007

Water Quality Modelling In Dublin From Bray To Balbriggan Gdsds/75407/130, Aodh Dowley, Zeinab Bedri

Reports

No abstract provided.


The Structural Reliability Of Bridges Subject To Time-Dependent Deterioration, Colin C. Caprani, C. Mcnally, E. J. O'Brien, A. Bordallo-Ruiz Jan 2007

The Structural Reliability Of Bridges Subject To Time-Dependent Deterioration, Colin C. Caprani, C. Mcnally, E. J. O'Brien, A. Bordallo-Ruiz

Conference papers

The reliability of the structural performance of any given structure is affected by both in-service loading and material deterioration due to environmental attack. They must be evaluated at any given time in order to compute lifetime probability of failure. This paper presents an innovative methodology to derive the structure lifetime load effect due to existing traffic using a statistical tool known as Predictive Likelihood. Loss of resistance due to corrosion originated by chloride ingression is also taken into account. Finally the lifetime probability of failure is evaluated via the application of a time-discretization strategy.


Position And Orientation Correction For Pipe Profiling Robots, Andrew John Dettmer Jan 2007

Position And Orientation Correction For Pipe Profiling Robots, Andrew John Dettmer

Doctoral Dissertations

Sewer pipelines are prevalent, important, valuable, unnoticed, and often in a state of disrepair. Pipeline inspection is essential for effective management of wastewater systems and is now mandated for many municipalities complying with the Governmental Accounting Standards Board Statement 34 and EPA regulations. Pipe inspection robots are routinely used to inspect underground pipelines for cracks, deformations, leaks, blockages and other anomalies to prevent catastrophic failure and to ensure cost effective maintenance and renewal. Most existing pipe inspection robots only collect video footage of pipe condition. Pipe profiling technology has recently been introduced to allow for measurement of the internal coordinate …


Assessment Of The Safety Benefits Of Vms And Vsl Using The Ucf Driving Simulator, Cristina Dos Santos Jan 2007

Assessment Of The Safety Benefits Of Vms And Vsl Using The Ucf Driving Simulator, Cristina Dos Santos

Electronic Theses and Dissertations

Researchers at the University of Central Florida (UCF) have been working during the past few years on different strategies to improve freeway safety in real-time. An ongoing research at UCF has investigated crash patterns that occurred on a stretch of Interstate-4 located in Orlando, FL and created statistical models to predict in real-time the likelihood of a crash in terms of time and space. The models were then tested using PARAMICS micro-simulation and different strategies that would reduce the risk of crashes were suggested. One of the main recommended strategies was the use of Variable Speed Limits (VSL) which intervenes …


Dynamic Impact Testing Of W152x13.4 (W6x9) Steel Posts On A 2:1 Slope, Gopi Dey, Ronald K. Faller, John A. Hascall, Robert W. Bielenberg, Karla A. Polivka, Kirk Molacek Jan 2007

Dynamic Impact Testing Of W152x13.4 (W6x9) Steel Posts On A 2:1 Slope, Gopi Dey, Ronald K. Faller, John A. Hascall, Robert W. Bielenberg, Karla A. Polivka, Kirk Molacek

Mid-America Transportation Center: Final Reports and Technical Briefs

Dynamic impact testing of W152x13.4 (W6x9) steel posts at various embedment depths has been detailed, and the results stated. A total of 17 bogie tests have been performed on a 2:1 slope, with post lengths varying from 1,829 mm (6 ft) through 2,743 mm (9 ft). A total of four bogie tests were performed on level terrain using 1,829-mm (6-ft) long steel posts at two different impact speeds. For each bogie test, raw acceleration data, obtained from accelerometers, was filtered and then force-displacement and energy-displacement graphs were plotted. From the energy-displacement graphs, the average post-soil forces were calculated for a …


The Design And Performance Of Pressure Pipe Liners Under Static And Cyclic Loading, Shanhai Guan Jan 2007

The Design And Performance Of Pressure Pipe Liners Under Static And Cyclic Loading, Shanhai Guan

Doctoral Dissertations

Cured-in-place pipe (CIPP), is a widely used trenchless technology. Based on the current liner design method, American Society for Testing and Materials (ASTM) F2207-02, several aspects are studied for the effect on estimating the long-term performance of the liners.

While estimating the liner burst pressure, the effect from host pipe material properties, liner material properties, defect geometry, liner creep properties and loading condition should be considered. The burst pressure calculated based on the existing method is overestimated and this allows an increased risk of structural failure before the expected design life is reached.

Compared with cast-iron, a PVC host pipe …


Spacecraft Loads Predictionvia Sensitivity Analysis And Optimization, Tom Braswell Jan 2007

Spacecraft Loads Predictionvia Sensitivity Analysis And Optimization, Tom Braswell

Electronic Theses and Dissertations

Discrepancies between the predicted responses of a finite element analysis (FEA) and reference data from test results arise for many reasons. Some are due to measurement errors, such as inaccurate sensors, noise in the acquisition system or environmental effects. Some are due to analyst errors precipitated by a lack of familiarity with the modeling or solver software. Still others are introduced by uncertainty in the governing physical relations (linear versus non-linear behavior), boundary conditions or the element material/geometrical properties. It is the uncertainty effects introduced by this last group that this study seeks to redress. The objective is the obtainment …


Exploring The Potential Of Combining Ramp Metering And Variable Speed Limit Strategies For Alleviating Real-Time Crash Risk On Urban Freeways, Kirolos Maged Haleem Jan 2007

Exploring The Potential Of Combining Ramp Metering And Variable Speed Limit Strategies For Alleviating Real-Time Crash Risk On Urban Freeways, Kirolos Maged Haleem

Electronic Theses and Dissertations

Research recently conducted at the University of Central Florida involving crashes on Interstate-4 in Orlando, Florida has led to the creation of new statistical and neural networks models that are capable of determining the crash risk on the freeway (Abdel-Aty et al., 2004; 2005, Pande and Abdel-Aty, 2006). These models are able to calculate rear-end and lane-change crash risks along the freeway in real-time through the use of static information at various locations along the freeway as well as real-time traffic data obtained by loop detectors. Since these models use real-time traffic data, they are capable of calculating rear-end and …


Evaluating The Impact Of Oocea S Dynamic Message Signs (Dms) On Travelers Experience Using The Pre-Deployment Survey, John Hill Rogers Jan 2007

Evaluating The Impact Of Oocea S Dynamic Message Signs (Dms) On Travelers Experience Using The Pre-Deployment Survey, John Hill Rogers

Electronic Theses and Dissertations

The purpose of this thesis was to evaluate the impact of dynamic message signs (DMS) on the Orlando-Orange County Expressway Authority (OOCEA) toll road network using the Pre-Deployment DMS Survey (henceforth referred to as "pre-deployment survey"). DMS are electronic traffic signs used on roadways to give travelers information about travel times, traffic congestion, accidents, disabled vehicles, AMBER alerts, and special events. The particular DMS referred to in this study are large rectangular signs installed over the travel lanes and these are not the portable trailer mount signs. The OOCEA is currently in the process of adding several fixed DMS on …


Target Element Sizes For Finite Element Tidal Models From A Domain-Wide, Localized Truncation Error Analysis Incorporating Botto, Denwood Parrish Jan 2007

Target Element Sizes For Finite Element Tidal Models From A Domain-Wide, Localized Truncation Error Analysis Incorporating Botto, Denwood Parrish

Electronic Theses and Dissertations

A new methodology for the determination of target element sizes for the construction of finite element meshes applicable to the simulation of tidal flow in coastal and oceanic domains is developed and tested. The methodology is consistent with the discrete physics of tidal flow, and includes the effects of bottom stress. The method enables the estimation of the localized truncation error of the nonconservative momentum equations throughout a triangulated data set of water surface elevation and flow velocity. The method's domain-wide applicability is due in part to the formulation of a new localized truncation error estimator in terms of complex …


Input-Output And Hybrid Techniques For Real-Time Prediction Of Delay And Maximum Queue Length At Signalized Intersections, Anuj Sharma, Darcy M. Bullock, James A. Bonneson Jan 2007

Input-Output And Hybrid Techniques For Real-Time Prediction Of Delay And Maximum Queue Length At Signalized Intersections, Anuj Sharma, Darcy M. Bullock, James A. Bonneson

Department of Civil and Environmental Engineering: Faculty Publications

Vehicle delay and queue length are quantitative measures of intersection performance. The technological advancement in the field of vehicle sensors and traffic controllers has reached a point where it has enabled efficient measurement of these performance measures. Two techniques are presented for real-time measurement of vehicle delay and queue length at a signalized Intersection, and these automated delay and queue estimates are compared with manually ground-truthed measurement. These techniques were evaluated at an instrumented intersection in Noblesville, Indiana. The root-mean-square error by both techniques was below 0.7 veh-s for-estimation of average delay and less than 0.15 vehicle for estimation of …


A Weighted Residual Parabolic Acceleration Time Integration Method For Problems In Structural Dynamics, Ali Abolmaali, S.H. Razavi, M. Ghassemieh Jan 2007

A Weighted Residual Parabolic Acceleration Time Integration Method For Problems In Structural Dynamics, Ali Abolmaali, S.H. Razavi, M. Ghassemieh

Civil Engineering Faculty Publications - Archive

In the proposed method, the variation of displacement in each time step is assumed to be a fourth order polynomial in time and its five unknown coefficients are calculated based on: two initial conditions from the previous time step; satisfying the equation of motion at both ends of the time step; and the zero weighted residual within the time step. This method is non-dissipative and its dispersion is considerably less than in other popular methods. The stability of the method shows that the critical time step is more than twice of that for the linear acceleration method and its convergence …


Investigating The Use Of Small-Diameter Softwood As Guardrail Posts (Dynamic Test Results), Jason A. Hascall, Ronald K. Faller, John D. Reid, Dean L. Sicking, David E. Kretschmann Jan 2007

Investigating The Use Of Small-Diameter Softwood As Guardrail Posts (Dynamic Test Results), Jason A. Hascall, Ronald K. Faller, John D. Reid, Dean L. Sicking, David E. Kretschmann

Mid-America Transportation Center: Final Reports and Technical Briefs

A modified version of the Midwest Guardrail System (MGS), utilizing small-diameter round wood posts, was developed, tested, and evaluated. Three systems were developed using different species of timber, Douglas Fir, Ponderosa Pine, and Southern Yellow Pine. A combination of Barrier VII computer simulation modeling and several series of cantilever bogie tests, conducted in both a rigid sleeve and soil, were used to determine the required diameter of post for each species in order to serve as an equivalent substitute for the standard steel post used in the barrier system. The final recommended nominal sizes were determined to be 184 mm …


Enhancing The Capability Of Rapid Bridge Replacement After Extreme Events, Yong Bai, Seong Hoon Kim, William R. Burkett Jan 2007

Enhancing The Capability Of Rapid Bridge Replacement After Extreme Events, Yong Bai, Seong Hoon Kim, William R. Burkett

Civil and Environmental Engineering Faculty Research and Publications

Purpose

The potential threats of extreme events to highway bridges have received increased attention from government agencies, the engineering and construction communities, and the traveling public. These events include terrorist attacks as well as human‐induced and natural hazards such as earthquakes, explosions, fires, floods, and hurricanes. To respond to the potential threats on highway bridges, a research project was conducted to identify rapid bridge replacement processes, techniques, and needs for improvements.

Design/methodology/approach

To achieve the research objectives, a detailed case study of previous bridge replacement following an extreme event was conducted. The case study was performed using a three‐step approach. …


Effect Of Horizontal Piles On The Soil Bearing Capacity For Circular Footing Above Cavity, Rafael L. Arosemena Jan 2007

Effect Of Horizontal Piles On The Soil Bearing Capacity For Circular Footing Above Cavity, Rafael L. Arosemena

Electronic Theses and Dissertations

The design of foundation in normal soil conditions is governed by bearing capacity, minimum depth of foundation and settlement. However, foundation design in karst regions needs to consider an additional criterion associated to the possibility of subsurface subsidence and ravelling sinkholes. Under this environment, alternative techniques are needed to improve the subsurface soil. In this study general background information is given to understand the geological characteristics of Central Florida and why this area is considered to be a karst region and susceptible to sinkholes formation. Traditional foundation design techniques on karst regions are addressed in this paper. Finally, the use …


Parameter Estimation Using Sensor Fusion And Model Updating, Kevin Francoforte Jan 2007

Parameter Estimation Using Sensor Fusion And Model Updating, Kevin Francoforte

Electronic Theses and Dissertations

Engineers and infrastructure owners have to manage an aging civil infrastructure in the US. Engineers have the opportunity to analyze structures using finite element models (FEM), and often base their engineering decisions on the outcome of the results. Ultimately, the success of these decisions is directly related to the accuracy of the finite element model in representing the real-life structure. Improper assumptions in the model such as member properties or connections, can lead to inaccurate results. A major source of modeling error in many finite element models of existing structures is due to improper representation of the boundary conditions. In …


Pilot Study Of Nutrient Loading In A Wet Detention Lake, Eric C. Gurr Jan 2007

Pilot Study Of Nutrient Loading In A Wet Detention Lake, Eric C. Gurr

Electronic Theses and Dissertations

Florida is surrounded by water, and its many internal lakes and rivers have long been recognized for their excellent fishing and boating. This notoriety draws land developers to the lake shores to establish residential and commercial infrastructure. This land development brings with it flood plain alteration, water level stabilization, and increased nutrients which cause adverse impacts to our lakes. In response, the United States Environmental Protection Agency (EPA) passed the Federal Clean Water Act (CWA) in 1972 which set the framework for the water quality standards for the entire United States. As a result of the CWA many point sources …


Construction Specifications And Analysis Of Rehabilitation Techniques Of Pervious Concrete Pavement, Craig Ballock Jan 2007

Construction Specifications And Analysis Of Rehabilitation Techniques Of Pervious Concrete Pavement, Craig Ballock

Electronic Theses and Dissertations

The primary objective of this study is to evaluate the clogging potential of installed pervious concrete systems, to analyze rehabilitation techniques and develop construction specifications for the construction of portland cement pervious concrete specific to the state of Florida. Currently, a consistent statewide policy has not been established in reference to credit for storage volume within the voids in pervious concrete and the coarse aggregate base. For this reason a current and updated assessment of pervious pavement is needed to benefit from the advantages of pervious pavement use in low traffic volume areas. Initially by modeling a pervious concrete system …


Examining Dynamic Variable Speed Limit Strategies For The Reduction Of Real-Time Crash Risk On Freeways, Ryan Cunningham Jan 2007

Examining Dynamic Variable Speed Limit Strategies For The Reduction Of Real-Time Crash Risk On Freeways, Ryan Cunningham

Electronic Theses and Dissertations

Recent research at the University of Central Florida involving crashes on Interstate-4 in Orlando, Florida has led to the creation of new statistical models capable of determining the crash risk on the freeway (Abdel-Aty et al., 2004; 2005, Pande and Abdel-Aty, 2006). These models are able to calculate the rear-end and lane-change crash risks along the freeway in real-time through the use of static information at various locations along the freeway as well as the real-time traffic data obtained by loop detectors. Since these models use real-time traffic data, they are capable of calculating rear-end and lane-change crash risk values …


Dynamic Speed Monitoring System Effectiveness On Sharp Curves, Vasu Tavasna Persaud Jan 2007

Dynamic Speed Monitoring System Effectiveness On Sharp Curves, Vasu Tavasna Persaud

Electronic Theses and Dissertations

The design of rural interchanges is of critical concern due to the need for the safe transition of vehicles from one high speed roadways to another and vice versa. This transition is accomplished by entry and exit ramps of various forms. The southbound entry loop ramp at the US 27/ US 192 trumpet interchange in Polk County, Florida does not provide such safe transition since historically there has been a high incidence of vehicular off-tracking. The geometry of the southbound entry ramp coupled with high approach speeds are two of the contributing factors. Due to the high cost of interchange …


Development Of A Decision Support System For Selection Of Trenchless Technologies To Minimize Impact Of Utility Construction On Roadways, Dulcy M. Abraham, Hyeon-Shik Baik, Sanjiv B. Gokhale Jan 2007

Development Of A Decision Support System For Selection Of Trenchless Technologies To Minimize Impact Of Utility Construction On Roadways, Dulcy M. Abraham, Hyeon-Shik Baik, Sanjiv B. Gokhale

JTRP Technical Reports

The need to replace deteriorating underground utility infrastructure and to expand utility services, increases the need for utility conduits to intersect roadways. Open-trench method is currently the most widely used method for installation of underground pipelines and conduits of all sizes. However, open-cut construction has several shortcomings, chief amongst which are: health and safety concerns of workers, surface disturbance, disruption to vehicular/pedestrian traffic and reduction of pavement life. Today, other cost-effective alternatives exist to traditional open-trench construction. These methods are categorized as "Trenchless Technologies" as they require minimum trenching (excavation). While the benefits of trenchless technology are quite apparent when …


Automated Composite Column Wrapping, Purdue Ect Team Jan 2007

Automated Composite Column Wrapping, Purdue Ect Team

ECT Fact Sheets Archive

The Automated Composite Column Wrapping is performed by a patented machine known as Robo-Wrapper. Currently there are three versions of the machine available for bridge retrofit work depending on the size of the columns being wrapped. Composite column retrofit jacket systems can be structurally just as effective as conventional steel jacketing in improving the seismic response characteristics of substandard reinforced concrete columns.


New Structural Material - Fiber Reinforced Plastics, Purdue Ect Team Jan 2007

New Structural Material - Fiber Reinforced Plastics, Purdue Ect Team

ECT Fact Sheets Archive

Traditional structural materials are heavy and require a great deal of maintenance. If a new breed of structural material could be produced that was lighter, stronger and more resistant to corrosion, impacts, parasites and chemicals, it could be a good substitute for steel, concrete, masonry and wood. One new material that has the potential to meet these demands is starting to show up on the construction industry market, it is Fiber Reinforced Plastics (FRP). Some technologies that have been developed using FRP materials within the last few years are: structural shapes, concrete reinforcing, prestressing and post-tensioning tendons and pre-engineered structural …