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2008

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Articles 91 - 120 of 206

Full-Text Articles in Civil Engineering

A Laboratory Study On The Effects Of Submerged Vertical And Semicircular Breakwaters On Near-Field Hydrodynamics And Morphodynamics, David Young May 2008

A Laboratory Study On The Effects Of Submerged Vertical And Semicircular Breakwaters On Near-Field Hydrodynamics And Morphodynamics, David Young

All Theses

A laboratory study is presented herein that investigates the effects of submerged vertical and semicircular breakwaters on near-field hydrodynamics and morphodynamics. Breakwaters are employed worldwide in order to reduce destructive wave forces often imparted on vulnerable shorelines; a task partially completed by reflecting incident wave energy back out to sea. However, two common side-effects of their function are the occurrence of scour at the breakwater, which can lead to structural problems; and offshore ripple formations, which are influential in scour protection failure and sediment transport patterns. This study aims to determine a relationship between breakwaters and the wave reflection coefficient …


Chemisorption Of Oxygen Onto Activated Carbon Can Enhance The Stability Of Biological Perchlorate Reduction In Fixed Bed Biofilm Reactors, Young Chul Choi, Xu Li, Lutgarde Raskin, Eberhard Morgenroth May 2008

Chemisorption Of Oxygen Onto Activated Carbon Can Enhance The Stability Of Biological Perchlorate Reduction In Fixed Bed Biofilm Reactors, Young Chul Choi, Xu Li, Lutgarde Raskin, Eberhard Morgenroth

Department of Civil and Environmental Engineering: Faculty Publications

Fixed bed biofilm reactors with granular activated carbon (GAC) or glass beads as support media were used to evaluate the influence of short-term (12 h) and long-term (23 days) increases of influent dissolved oxygen (DO) concentrations on biological perchlorate removal. The goal was to evaluate the extent by which chemisorption of oxygen to GAC can enhance the stability of biological perchlorate reduction. Baseline influent concentrations were 50 μg/L of perchlorate, 2 mg/L of acetate as C, and 1 mg/L of DO. Perchlorate removal in the glass bead reactor seized immediately after increasing influent DO concentrations from 1 to 4 mg/L …


Geotechnical Investigations At Three Sites In The South Carolina Coastal Plain That Did Not Liquefy During The 1886 Charleston Earthquake, Ronald Boller May 2008

Geotechnical Investigations At Three Sites In The South Carolina Coastal Plain That Did Not Liquefy During The 1886 Charleston Earthquake, Ronald Boller

All Theses

Geotechnical investigations were performed at three sites in the South Carolina Coastal Plain where liquefaction is believed to not have occurred in 1886 or during other Holocene earthquakes. The three sites are the Coastal Research and Education Center (CREC) located near Charleston, and the Borrow Pit and Marsh Road sites at Hobcaw Barony near Georgetown. The investigations consisted of nine seismic cone penetration test (SCPT) soundings, three non-seismic cone penetration test (CPT) soundings, one standard penetration test (SPT) boring, and two dilatometer test (DMT) soundings. Shear wave velocities (Vs) were calculated from the SCPTs using pseudo interval measurements at the …


A Relational Model For Environmental And Water Resources Data, Jeffery S. Horsburgh, David G. Tarboton, David R. Maidment, Ilya Zaslavsky May 2008

A Relational Model For Environmental And Water Resources Data, Jeffery S. Horsburgh, David G. Tarboton, David R. Maidment, Ilya Zaslavsky

Civil and Environmental Engineering Faculty Publications

Environmental observations are fundamental to hydrology and water resources, and the way these data are organized and manipulated either enables or inhibits the analyses that can be performed. The Observations Data Model presented here provides a new and consistent format for the storage and retrieval of point environmental observations in a relational database designed to facilitate integrated analysis of large data sets collected by multiple investigators. Within this data model, observations are stored with sufficient ancillary information (metadata) about the observations to allow them to be unambiguously interpreted and to provide traceable heritage from raw measurements to useable information. The …


A Comparison Of Nondestructive Testing Backcalculation Techniques For Rigid And Flexible Pavements, Trenton Ellis May 2008

A Comparison Of Nondestructive Testing Backcalculation Techniques For Rigid And Flexible Pavements, Trenton Ellis

Civil Engineering Undergraduate Honors Theses

In designing new pavements, engineers rely on many different measures to characterize the average traffic, climate and soil conditions of the region. Of those, soil conditions are the most elusive, but are also the most crucial for designing a pavement of proper thickness and stiffness. This problem is compounded when the design is for an overlay instead of a new pavement. For overlay designs, engineers require a quantitative characterization of the strength of the existing pavement as well as the underlying soil. Especially for new Mechanistic-Empirical design procedures, direct measures and/or estimates of pavement stiffness are essential inputs. A variety …


Analysis Of The Impact Of Fuel Price And Bidding Volume On The Engineer's Estimate, Greaton Sellers May 2008

Analysis Of The Impact Of Fuel Price And Bidding Volume On The Engineer's Estimate, Greaton Sellers

All Theses

The research project 'Analysis of the Impact of Fuel Price and Bidding Volume on the Engineer's Estimate' was initiated by the South Carolina Department of Transportation and conducted by Clemson University. This research was executed as a two part study, 'Best Practices for Developing the Engineer's Estimate', which addressed two distinct but related objectives. The first research objective was to fully explore the advantages and disadvantage of alternative methodologies utilized to compile the engineer's cost estimate. This research objective is addressed in Report Volume I. The second research objective, which is addressed in this Report Volume II, was to develop …


Knowledge-Based System To Support Site Investigation For Safety Improvement, Andrew P. Tarko, Andrew Kwasniak, Jorge Ramos May 2008

Knowledge-Based System To Support Site Investigation For Safety Improvement, Andrew P. Tarko, Andrew Kwasniak, Jorge Ramos

JTRP Technical Reports

Specialists in transportation and other areas of engineering are trying to improve road safety. The most difficult part is determining the road features, driver behaviors, and vehicular failures that unduly increase the risk of crash. To help INDOT safety investigation teams, a previous research project developed a prototype Road Safety Investigation Tool (RSIT) for two-way stop-controlled intersections. The research summarized here has evaluated the prototype RSIT and has developed a new version RSIT2 that has incorporated the findings of the evaluation.

The evaluation of the RSIT prototype confirmed usefulness of the proposed methodology. The tool has been applied to two …


A Laboratory Study Of Streambed Stability In Bottomless Culverts, Brian Mark Crookston May 2008

A Laboratory Study Of Streambed Stability In Bottomless Culverts, Brian Mark Crookston

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Traditional culvert designs, in many cases, have become habitat barriers to aquatic animal species. In response, environmentally sensitive culvert designs have been developed to function as ecological bridges. Bottomless and buried invert culverts are examples of such designs and are commonly used for fish passage. Additional design guidance specific to streambed stability in buried-invert or bottomless culverts under high flow events is needed. This study investigated incipient motion conditions for four substrate materials in a 2-ft (0.61-m) diameter circular bottomless arch culvert and in a 1-ft (0.30-m) wide rectangular flume in a laboratory setting. General scour of the streambed within …


Transitional Flow Between Orifice And Non-Orifice Regimes At A Rectangular Canal Gate, Omar Alminagorta Cabezas May 2008

Transitional Flow Between Orifice And Non-Orifice Regimes At A Rectangular Canal Gate, Omar Alminagorta Cabezas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The main objective of this research was to analyze the hydraulic transition between non-orifice and orifice flow regimes at a rectangular sluice gate through the calibration of various discharge equations, and determining the value of a coefficient, which defines the transition between orifice and non-orifice flow conditions. The second objective was to determine whether a single equation could be used to represent the stage-discharge relationship for both free and submerged non-orifice flow through a rectangular sluice gate.

Several hundred data sets were collected in a hydraulic laboratory, each including the measurement of water upstream depth and downstream for five different …


Bridge Instrumentation And The Development Of Non-Destructive And Destructive Techniques Used To Estimate Residual Tendon Stress In Prestressed Girders, Brian Michael Kukay May 2008

Bridge Instrumentation And The Development Of Non-Destructive And Destructive Techniques Used To Estimate Residual Tendon Stress In Prestressed Girders, Brian Michael Kukay

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research embodied a three-prong approach for directly determining the residual prestress force of prestressed concrete bridge girders. For bridges that have yet to be constructed, outfitting girders with instrumentation is a highly effective means of determining residual prestress force in prestressed concrete bridge girders. This constitutes the first prong. Still, many bridges are constructed without such instrumentation. For these bridges, a destructive technique can be used to directly determine the residual prestress in a prestressed concrete bridge girder. This implies that the girder(s) being tested have already been taken out of service. This constitutes the second prong.

For bridges …


Bs News May 2008

Bs News

Building Services Engineering

No abstract provided.


Factors Affecting The Performance Of Brick Veneer Construction, Jocelyn Dickie May 2008

Factors Affecting The Performance Of Brick Veneer Construction, Jocelyn Dickie

All Theses

The first topic focused on in this report is the height restriction imposed by the masonry standard for brick veneer on wood frame backing. The current US standard (ACI 530-05/ASCE 5-05/TMS 402-05 Building Code Requirements for Masonry Structures) does not allow brick veneer to extend more than thirty feet above the foundation when supported by wood framing. These prescriptive requirements are compared with those of the Canadian (CSA 304.1-04) and Australian (AS 3700-2001) masonry standards. The logic found for this height restriction is based on the vertical differential movement caused by moisture and thermal expansion of the brick veneer and …


Development Of Prediction Models Of High Temperature Crumb Rubber Modified Binders, Carl Thodesen May 2008

Development Of Prediction Models Of High Temperature Crumb Rubber Modified Binders, Carl Thodesen

All Dissertations

The purpose of this research was to identify and model critical elements of the asphalt rubber matrix contributing to the crumb rubber modified (CRM) binder properties as measured by Superpave testing procedures. Current models are neither applicable (due to new testing procedures) nor practical (due to the difficulty of application or lack of accuracy). Therefore, this research investigated the development of predictive models for estimating binder properties within a specified range of accuracy.
Multiple crumb rubber sources were evaluated in order to gain an understanding of the differences between the various crumb rubbers. This analysis permitted identification of the important …


Effects Of Warm Asphalt Additives On Asphalt Binder And Mixture Properties, Tejash Gandhi May 2008

Effects Of Warm Asphalt Additives On Asphalt Binder And Mixture Properties, Tejash Gandhi

All Dissertations

With increasing concerns of global warming and increasing emissions, the asphalt industry is making a constant effort to lower its emissions by reducing the mixing and compaction temperatures of the asphalt mixture without affecting the properties of the mix. Several proprietary chemicals are available in the industry that can help reduce the mixing and compaction temperatures. A significant reduction of required heat can be achieved in most cases. While some studies have been conducted to evaluate the properties of warm mix asphalt; properties of binders and mixtures, in fresh and aged conditions, containing these chemicals have not been studied in …


Calculated Surface Velocity Coefficients For Prismatic Open Channels By Three-Dimensional Hydraulic Modeling, Nat Marjang May 2008

Calculated Surface Velocity Coefficients For Prismatic Open Channels By Three-Dimensional Hydraulic Modeling, Nat Marjang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A turbulence model was developed for computing surface velocity coefficients and discharge under steady, uniform flow conditions for rectangular and compound open-channel cross sections. Reynolds-Average Navier-Stokes (RANS) equations, Reynolds stress equations, and kinetic energy and dissipation equations were applied in the model using the finite-volume method with the SIMPLER algorithm. The models show graphical results of the velocity distributions in the longitudinal bed slope direction, secondary velocities, pressure, turbulence kinetic energy, and kinetic energy dissipation rate across the cross section. Also, the surface velocity coefficients were computed at increments of one-eighth of the base width from the vertical walls to …


A Collection Of New Studies Using Existing And Proposed Techniques And Instrumentation For Nondestructive Testing And Analysis Of Concrete Materials And Structures, Shane D. Boone May 2008

A Collection Of New Studies Using Existing And Proposed Techniques And Instrumentation For Nondestructive Testing And Analysis Of Concrete Materials And Structures, Shane D. Boone

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A variety of studies were performed using existing and newly proposed techniques and instrumentation to further the understanding of nondestructive testing of concrete. A new combined stress wave propagation method was developed that combined the existing methods of the spectral analysis of surface waves, impact echo, and free-free resonant column experimental and analysis techniques. The method was used to determine the stiffness profile and location of embedded voids in a concrete tunnel lining modeled as a three layer concrete slab. A new equation was proposed that predicted the level of damage of concrete samples based on the functions of the …


Models And Algorithms For Addressing Travel Time Variability: Applications From Optimal Path Finding And Traffic Equilibrium Problems, Zhong Zhou May 2008

Models And Algorithms For Addressing Travel Time Variability: Applications From Optimal Path Finding And Traffic Equilibrium Problems, Zhong Zhou

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An optimal path finding problem and a traffic equilibrium problem are two important, fundamental, and interrelated topics in the transportation research field. Under travel time variability, the road networks are considered as stochastic, where the link travel times are treated as random variables with known probability density functions. By considering the effect of travel time variability and corresponding risk-taking behavior of the travelers, this dissertation proposes models and algorithms for addressing travel time variability with applications from optimal path finding and traffic equilibrium problems. Specifically, two new optimal path finding models and two novel traffic equilibrium models are proposed in …


Sustainable Portland: Implementation Series 1, New England Environmental Finance Center Apr 2008

Sustainable Portland: Implementation Series 1, New England Environmental Finance Center

Climate Change

When the Sustainable Portland Task Force Report was released in November 2007, under the leadership of Mayor Jim Cohen, Portland Councilor Kevin Donoghue had the idea that students at the Muskie School of Public Service might be able to help implement recommendations from the report. It may have helped that Kevin was himself a graduate of the Community Planning and Development Master’s program at the Muskie School, but it was a good idea nevertheless. He approached Professor Sam Merrill in the CPD program, who spoke with the new Mayor Ed Suslovic about a possible partnership between the City and the …


Impact Of Lateral Swell Pressure On Retaining Structure Design Using Expansive Cohesive Backfill, Mark G. Thomas Apr 2008

Impact Of Lateral Swell Pressure On Retaining Structure Design Using Expansive Cohesive Backfill, Mark G. Thomas

Civil Engineering Theses - Archive

Since cohesive soils are difficult to drain once becoming saturated, in order to reduce lateral earth pressures exerted by saturated cohesive soils on retaining structures, retaining wall designs most always specify use of drainable granular backfill. However, costs for the importation of granular backfill materials continues to increase due to depletion of these materials in certain areas, and to the ever-increasing costs for material transportation, largely related to increased labor and fuel prices. These factors, together with the costs of removing replaced cohesive materials, and coupled with resource and environmental conservation concerns, are driving efforts to develop reasonable and prudent …


Non-Linear Finite Element Dynamic Analysis Of Tapered Hollow Steel Poles For Passive Base Isolation, Tri Le Apr 2008

Non-Linear Finite Element Dynamic Analysis Of Tapered Hollow Steel Poles For Passive Base Isolation, Tri Le

Civil Engineering Dissertations - Archive

Long tapered poles are commonly used to support Closed Circuit Television (CCTV) Cameras for security and traffic monitoring. Images received from CCTV are normally distorted depending on the wind induced vibration characteristics of the forcing function. To reduce image distortion, three approaches are integrated to optimize the process, which are: (1) development of equations for pole's frequency of vibration in terms of its geometric variables; (2) development of a mechanical damping device to isolate the pole's vibration from that of the camera; and (3) development of an electrical image processing device for image corrections. The identification of a pole's natural …


Dynamic Properties Of Compacted Soils Using Resonant Column With Self-Contained Bender Elements, Roshnara Mohammad Apr 2008

Dynamic Properties Of Compacted Soils Using Resonant Column With Self-Contained Bender Elements, Roshnara Mohammad

Civil Engineering Theses - Archive

A comprehensive series of resonant column and bender elements tests were simultaneously performed in the developed RC/BE apparatus. RC/BE tests were conducted on compacted specimens of poorly graded sand (SP) and high plasticity clay (CH) prepared at different moisture contents (17.7, 22.1, 25.5, 30.2% by weight for clay, and 5, 10, 15, 20% by weight for sand) and under different confining pressures (0, 2.5, 5.0, and 10.0 psi, or 0, 17.2, 34.4, 69.0 kPa) in order to assess the influence of key environmental factors, such as compaction induced suction and confining pressure, on small-strain stiffness properties of unsaturated soils, such …


Determination Of Creep Compliance And Tensile Strength Of Hot-Mix Asphalt For Wearing Courses In Missouri, David Newton Richardson, S. M. Lusher Apr 2008

Determination Of Creep Compliance And Tensile Strength Of Hot-Mix Asphalt For Wearing Courses In Missouri, David Newton Richardson, S. M. Lusher

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Creep compliance and indirect tensile (IDT) strength of hot-mix asphalt (HMA) are the two primary inputs to the low-temperature or thermal cracking module in the new Mechanistic-Empirical Pavement Design Guide (M-E PDG) software. Creep compliance is defined as time-dependent strain per unit stress, while IDT strength is best defined as HMA strength when subjected to tension. AASHTO T 322 test protocol was used as reference for this work. However in preparation for the laboratory work performed at the Missouri University of Science and Technology many experts were consulted as to how IDT creep/strength testing and calculations are actually being performed. …


A Study Of Co2 Absorption Using Jet Bubble Column, Setiadi Setiadi, Nita Tania Hadiyani, Hantizen Hantizen, Dijan Supramono Apr 2008

A Study Of Co2 Absorption Using Jet Bubble Column, Setiadi Setiadi, Nita Tania Hadiyani, Hantizen Hantizen, Dijan Supramono

Makara Journal of Technology

A Study of CO2 Absorption Using Jet Bubble Column. The phenomenon of plunging jet gas-liquid contact occurs quite often in nature, it's momentum carries small air bubbles with it into the reactor medium. The momentum of the liquid stream can be sufficient to carry small bubbles completely to the bottom of the vessel. A stream of liquid falling toward a level surface of that liquid will pull the surrounding air along with it. It will indent the surface of the liquid to form a trumpet-like shape. If the velocity of the stream is high enough, air bubbles will be pulled …


Limit States And Load And Resistance Design Of Slopes And Retaining Structures, Dongwook Kim, Rodrigo Salgado Apr 2008

Limit States And Load And Resistance Design Of Slopes And Retaining Structures, Dongwook Kim, Rodrigo Salgado

JTRP Technical Reports

Load and Resistance Factor Design (LRFD) methods for slopes and MSE walls were developed based on probability theory. The complexity in developing LRFD for slopes and MSE walls results from the fact that (1) the representation of spatial variability of soil parameters of slopes using Gaussian random field is computationally demanding and (2) LRFD of MSE walls requires examination of multiple ultimate limit states for both external and internal stability checks.

For each design case, a rational framework is developed accounting for different levels of target probability of failure (or target reliability index) based on the importance of the structure. …


Comparison Of Characteristics Between Fatal And Injury Accidents In The Highway Construction Zones, Yingfeng Li, Yong Bai Apr 2008

Comparison Of Characteristics Between Fatal And Injury Accidents In The Highway Construction Zones, Yingfeng Li, Yong Bai

Civil and Environmental Engineering Faculty Research and Publications

Highway construction zone safety has been a research focus in many countries for many decades. In the United States, regardless of the research efforts devoted, highway construction zones remain a serious safety concern for government agencies, legislatures, the highway industry, and the traveling public. In this study, the fatal and injury accidents between 1992 and 2004 in Kansas highway construction zones were examined systematically and their major characteristics were compared. The results showed significant differences between fatal and injury accidents in the construction zones. The researchers found that: (1) head-on was the dominant type for fatal accidents while rear-end was …


Parallel Mpi/Fortran Finite Element Symmetrical/Unsymmetrical Domain Decomposition, Siroj Tungkatara Apr 2008

Parallel Mpi/Fortran Finite Element Symmetrical/Unsymmetrical Domain Decomposition, Siroj Tungkatara

Civil & Environmental Engineering Theses & Dissertations

MPI/FORTRAN finite element analysis software based on Domain Decomposition (DD) formulas has been developed in this work. Efficient input data storage/data communication schemes, domain partitioning, fast symbolical and numerical sparse assembly, symmetrical/unsymmetrical sparse solver and robust symmetrical/unsymmetrical iterative solvers algorithms are all incorporated into the developed code. Parallel Precondition Conjugated Gradient (PCG) and Flexible Generalized Minimum Residual (FGMRES) are developed. Efficient computational techniques used in the developed code are explained. Numerical performance and the accuracy of the developed code are conducted on acoustic examples with medium to large grid sizes. The results obtained from ODU Wilbur cluster (under parallel processing …


Bs News Apr 2008

Bs News

Building Services Engineering

No abstract provided.


The Development Of Inverter Fuzzy Logic Control For Induction Motor Control By Vector Control Method In Electric Vehicle, Era Purwanto, Mohammad Ashary, Subagio Subagio, Mauridhi Heri Purnomo Apr 2008

The Development Of Inverter Fuzzy Logic Control For Induction Motor Control By Vector Control Method In Electric Vehicle, Era Purwanto, Mohammad Ashary, Subagio Subagio, Mauridhi Heri Purnomo

Makara Journal of Technology

The development of Inverter Fuzzy Logic Control for Induction Motor Control by Vector Control Method in Electric Vehicle. In response to concerns about energy cost, energy dependence, and environmental damage, a rekindling of interest in electric vehicles (EV’s) has been obvious. Thus, the development of power electronics technology for EV’s will take an accelerated pace to fulfill the market needs, regarding with the problem in this paper is presented development of fuzzy logic inverter in induction motor control for electric vehicle propulsion. The Fuzzy logic inverter is developed in this system to directed toward developing an improved propulsion system for …


Internet Congestion Control System, Pranoto Hidaya Rusmin, Carmadi Machbub, Agung Harsoyo, Hendrawan Hendrawan Apr 2008

Internet Congestion Control System, Pranoto Hidaya Rusmin, Carmadi Machbub, Agung Harsoyo, Hendrawan Hendrawan

Makara Journal of Technology

Internet Congestion Control System. Internet congestion occurs when resource demands exceeds the network capacity. But, it is not the only reason. Congestion can happen on some users because some others user has higher sending rate. Then some users with lower sending rate will experience congestion. This partial congestion is caused by inexactly feedback. At this moment congestion are solved by the involvement of two controlling mechanisms. These mechanisms are flow/congestion control in the TCP source and Active Queue Management (AQM) in the router. AQM will provide feedback to the source a kind of indication for the occurrence of the congestion …


Substrates Preparation From Woody Tropical Waste Biomass For Biohydrogen Production, Dwi Susilaningsih, Theresia Umi Harwati, Khairul Anam, Yopi Yopi Apr 2008

Substrates Preparation From Woody Tropical Waste Biomass For Biohydrogen Production, Dwi Susilaningsih, Theresia Umi Harwati, Khairul Anam, Yopi Yopi

Makara Journal of Technology

Substrates Preparation from Woody Tropical Waste Biomass for Biohydrogen Production. Addressing to the global warming problem, energy crisis and pollution, hydrogen production by micro-organisms using biotechnological approach should be considered, since it fulfils the recent society requirement to safely produce, renewable and environmental friendly energy. Hydrogen is one of the most promising green energy sources, because it is easily converted to electricity and cleanly combustible. There are three types of micro-organisms for hydrogen production, the first is cyanobacteria through the photosynthesis process, the second is anaerobic bacteria, which use organic substances as electron donor and energy and convert them to …