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2014

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Articles 211 - 240 of 1522

Full-Text Articles in Civil and Environmental Engineering

Environmental Systems Analysis - Penn State, University Park, Douglas A. Haith Oct 2014

Environmental Systems Analysis - Penn State, University Park, Douglas A. Haith

All ECSTATIC Materials

Undergraduate course in environmental systems analysis offered at Penn State, University Park in Fall 2014.


Environmental Engineering Systems, Mark Houck Oct 2014

Environmental Engineering Systems, Mark Houck

All ECSTATIC Materials

Introduces the concepts and applications of systems analysis in environmental engineering. Tools and methodologies of systems analysis are applied to improve the understanding and resolution of complex environmental engineering problems related to air, soil, and water quality and pollution. Scientific, engineering, political, social, legal, regulatory, medical, economic, and financial impacts of environmental engineering decisions are considered. Course taught at George Mason University.


The Structure-Function Relationship Of Pamam Dendrimers As Robust Oil Dispersants, Nicholas K. Geitner, Bo Wang, Rachel E. Andorfer, David A. Ladner, Pu Chen Ke, Feng Ding Oct 2014

The Structure-Function Relationship Of Pamam Dendrimers As Robust Oil Dispersants, Nicholas K. Geitner, Bo Wang, Rachel E. Andorfer, David A. Ladner, Pu Chen Ke, Feng Ding

Publications

PAMAM dendrimers have recently been investigated as efficient and biocompatible oil dispersants utilizing their encapsulation capacity; however, their high cationic charge density has been shown to be cytotoxic. It is therefore imperative to mitigate cationic charge-induced toxicity and understand the effects of such changes. Presented here is a synergistic experimental and computational approach to examine the effects of varying terminal surface charge on the capacity of dendrimers to disperse model liner, polycyclic aromatic, and hybrid hydrocarbons. Uncharged dendrimers collapse by forming intramolecular hydrogen bonds, which reduce the hosting capability. On the other hand, changing the surface charges from positive to …


Capacity-Related Driver Behavior On Modern Roundabouts Built On High-Speed Roads, Shaikh Ahmad Oct 2014

Capacity-Related Driver Behavior On Modern Roundabouts Built On High-Speed Roads, Shaikh Ahmad

Open Access Theses

The objective of this thesis was to investigate the factors that affect capacity-related driver behavior on modern roundabouts built on high-speed roads. The capacity of roundabouts is strongly affected by the behavior of drivers as represented by critical headway (critical gap) and follow-up headway (follow-up time). The effects of heavy vehicles (single-unit truck, bus, and semi-trailer) and area type (rural or urban) on roundabout capacity were investigated by comparing the critical headways for roundabouts located on high-speed and low-speed roads. The effects of nighttime conditions (in the presence of street lighting) were also considered. Data were collected using the Purdue …


Strategies For The Replacement Of Historic Bridge Guardrails, Adam J. Clauss Oct 2014

Strategies For The Replacement Of Historic Bridge Guardrails, Adam J. Clauss

Open Access Theses

Bridges that are designated historic present a special challenge to bridge engineers whenever rehabilitation work or improvements are made to the bridges. Federal and state laws protect historically significant bridges, and railings on these bridges can be subject to protection because of the role they play in aesthetics. Unfortunately, original railings on historic bridges do not typically meet current crash-test requirements and typically do not meet current standards for railing height and size of permitted openings. The objective of this study is to develop strategies that can be used to address existing railings on historic bridges and to develop solutions …


Interdisciplinary, Collaborative International Service Learning: Developing Engineering Students As Global Citizens, Anthony D. Songer, Karen R. Breitkreuz Oct 2014

Interdisciplinary, Collaborative International Service Learning: Developing Engineering Students As Global Citizens, Anthony D. Songer, Karen R. Breitkreuz

Construction Management Faculty Publications and Presentations

Recent calls to reform engineering education place emphasis on applied math and science within the broader context of globalization, economics, the environment, and society. This broad and complex challenge necessitates the investigation of new interdisciplinary education approaches for engineering education. This paper presents a formal approach for developing engineering students as global citizens. The 360 Degree Model for Educating Socially Responsible Global Citizens (360 Global Ed model) presented herein includes a framework for foundational theory, educational environment, academic coursework, and outcomes. At the core of the emerging model is an international service learning experience called the Village Network. …


Construction Management Service Learning: A "How To" Process For Success, R. Casey Cline, Ken Robson, Michael Kroth Oct 2014

Construction Management Service Learning: A "How To" Process For Success, R. Casey Cline, Ken Robson, Michael Kroth

Construction Management Faculty Publications and Presentations

To ensure that students are prepared for positions in the construction industry, construction management education programs expose students to industry relevant construction management (CM) theory and practice. Traditional transmission teaching methodologies, while arguably effective for teaching management theory and practice, are not as effective for the transfer of practical leadership skills and knowledge of construction specific processes. As an alternative teaching strategy, many CM programs incorporate service-learning (S-L) into curricula; providing students practical experience, focusing on the acquisition of knowledge through goal setting, thinking, planning, experimentation, observation, and reflection.

However, from a practical standpoint, the development of a service-learning project …


Kentucky Traffic Collision Facts 2013, Kentucky Transportation Center, Kentucky State Police Oct 2014

Kentucky Traffic Collision Facts 2013, Kentucky Transportation Center, Kentucky State Police

Kentucky Transportation Center Research Report

KENTUCKY’S TRAFFIC COLLISION FACTS report for 2013 is based on collision reports submitted to the Kentucky State Police Records Branch. As required by Kentucky Revised Statutes 189.635, “every law enforcement agency whose officers investigate a vehicle accident of which a report must be made…shall file a report of the accident…within ten days after investigation of the accident upon forms supplied by the bureau.” The stated purpose of this requirement is to utilize data on traffic collisions for such purposes as will improve the traffic safety program in the Commonwealth. Data contained in this report are based solely on the observations …


High Voltage Rear Electric Drivetrain Design For A Parallelthrough-The-Road Plug-In Hybrid Electric Vehicle, Adam Garrett Fogarty Oct 2014

High Voltage Rear Electric Drivetrain Design For A Parallelthrough-The-Road Plug-In Hybrid Electric Vehicle, Adam Garrett Fogarty

Open Access Theses

Purdue University was selected as one of 15 universities to participate in a three year Advanced Vehicle Technology Competition (AVTC) called EcoCar2: Plugging Into the Future. The vehicle built by the Purdue team was a Parallel-Through-The-Road Plug-in Hybrid Electric Vehicle (PTTR PHEV). The vehicle utilized a B20 diesel powertrain to power the front wheels, as well as a custom electric drivetrain to power the rear wheels. Using this vehicle during the final year of the competition, the team was successful in placing 4th overall as well as 2nd in the category of Well-To-Wheel (WTW) Greenhouse Gas Emissions. A stock 2013 …


Spatial And Temporal Patterns Of Geo-Tagged Tweets, Yue Li Oct 2014

Spatial And Temporal Patterns Of Geo-Tagged Tweets, Yue Li

Open Access Theses

With over 500 million current registered users and over 500 million tweets per day, Twitter has caught the attention of scientists in various disciplines. As Twitter allows users to send messages with location tags, a massive amount of valuable geo-social knowledge is embedded in tweets, which can provide useful implications for human geography, urban science, location-based service, targeted advertising, and social network studies. This thesis aims to determine the lifestyle patterns of college students by analyzing the spatial and temporal dynamics in their tweets. Geo-tagged tweets are collected over a period of six months for four US Midwestern college cites: …


Using A Centrifuge For Quality Control Of Pre-Wetted Lightweight Aggregate In Internally Cured Concrete, Albert E. Miller Oct 2014

Using A Centrifuge For Quality Control Of Pre-Wetted Lightweight Aggregate In Internally Cured Concrete, Albert E. Miller

Open Access Theses

Early age shrinkage of cementitious systems can result in an increased potential for cracking which can lead to a reduction in service life. Early age shrinkage cracking can be particularly problematic for high strength concretes, which are often specified due to their high strength and low permeability. However, these high strength concretes frequently exhibit a reduction in the internal relative humidity (RH) due to the hydration reaction (chemical shrinkage) and self-desiccation which results in a bulk shrinkage, termed autogenous shrinkage, which is substantial at early ages. Due to the low permeability of these concretes, standard external curing is not always …


Evaluation Of Lane Use Management Strategies, Chaitanya Paleti Siva Sai Krishna Oct 2014

Evaluation Of Lane Use Management Strategies, Chaitanya Paleti Siva Sai Krishna

Open Access Theses

The limited funding available for roadway capacity expansion and the growing funding gap, in conjunction with the increasing congestion, creates a critical need for innovative lane use management options. Various cost-effective lane use management strategies have been implemented in the United States and worldwide to address these challenges. However, these strategies have their own costs, operational characteristics, and additional requirements for field deployment. Hence, there is a need for systematic methodologies to evaluate lane use management strategies.

In this thesis, a systematic simulation-based methodology is proposed to evaluate lane use management strategies. It involves identifying traffic corridors that are suitable …


Fire Behavior Of Bolted Connections, Qiaqia Zhu Oct 2014

Fire Behavior Of Bolted Connections, Qiaqia Zhu

Open Access Theses

Bolted connection failures have been observed in building fires and large-scale structural fire tests. Limited information is available on plate bearing behavior at elevated temperatures. The failure mode of a shear-tab connection could change from plate bearing failure to bolt shear failure between 400 (degree Celsius) °C to 600°C. Component-based models have been used to predict the behavior of bolted connections. Earlier researchers have developed simple mathematical models to represent the force-displacement relationships of bolt shear and plate bearing components of bolted connections. However, these models need to be verified experimentally for US building construction and materials. Therefore, eleven single-bolted …


A Stochastic Multi-Criteria Assessment Of Security Of Transportation Assets, Michelle Sophie Dojutrek Oct 2014

A Stochastic Multi-Criteria Assessment Of Security Of Transportation Assets, Michelle Sophie Dojutrek

Open Access Dissertations

Transportation project evaluation and prioritization use traditional performance measures including travel time, safety, user costs, economic efficiency, and environmental quality. The project impacts in terms of enhancing the infrastructure resilience or mitigating the consequences of infrastructure damage in the event of disaster occurrence are rarely considered in project evaluation. This dissertation presents a methodology to address this issue so that in evaluating and prioritizing investments, infrastructure with low security can receive the attention they deserve. Secondly, the methodology can be used for evaluating and prioritizing candidate investments dedicated specifically to security enhancement. In defining security as a function of threat …


Experimental Database, Analysis And Design Of Noncompact And Slender Concrete-Filled Steel Tube (Cft) Members, Zhichao Lai Oct 2014

Experimental Database, Analysis And Design Of Noncompact And Slender Concrete-Filled Steel Tube (Cft) Members, Zhichao Lai

Open Access Dissertations

Concrete-filled steel tube beam-columns are categorized as compact, noncompact or slender depending on the governing tube slenderness ratio. AISC 360-10 specifies the provisions for designing noncompact and slender rectangular and circular CFT members under axial compression, flexure, and combined axial and flexural loading. This research presents the development and evaluation of these design provisions. Available experimental databases of CFT members are reviewed, and a new experimental database of tests conducted on noncompact and slender CFT members is compiled. Detailed 3D finite element method (FEM) models are developed for noncompact and slender CFT members, and benchmarked using experimental results. The AISC …


A New Passive Surface Water Flux Meter For Simultaneous Measurement Of Contaminant And Water Fluxes In Streams And Rivers, Stephen A. Sassman Oct 2014

A New Passive Surface Water Flux Meter For Simultaneous Measurement Of Contaminant And Water Fluxes In Streams And Rivers, Stephen A. Sassman

Open Access Dissertations

A passive surface water flux meter (PSFM) for measurement of contaminant concentration/flux in rivers and streams is described and tested. The novel PSFM design was developed for portability and ease of adaptability for a variety of contaminant classes. Although previous designs have been evaluated under constant flow conditions, the PSFM has never been used for measurement of pesticides or hormones and this is the first time that it has been tested under transient flow. Discharge through the PSFM is assessed by measuring miscible displacement of alcohol tracers from granular activated carbon (GAC). The tracer retardation factors (R) measured by miscible …


Effects Of Web Reinforcement Discontinuities On The Seismic Response Of Structural Walls, Ying Wang Oct 2014

Effects Of Web Reinforcement Discontinuities On The Seismic Response Of Structural Walls, Ying Wang

Open Access Dissertations

Field evidence was interpreted to suggest that discontinuities in the longitudinal web reinforcement caused severe damage in structural walls during strong ground motion. To test this hypothesis, six small-scale reinforced concrete structural walls were tested under lateral displacement reversals. Test variables included the presence of web longitudinal reinforcement discontinuities and number of loading cycles. The test results indicated that unit tensile strains in longitudinal reinforcing bars in boundary elements were approximately 50% higher in structural walls with web longitudinal reinforcement cutoffs relative to walls without reinforcement cutoffs. Higher unit tensile strains caused an increase in permanent strain accumulation, increasing the …


Nano-Modification For High Performance Cement Composites With Cellulose Nanocrystals And Carbon Nanotubes, Yizheng Cao Oct 2014

Nano-Modification For High Performance Cement Composites With Cellulose Nanocrystals And Carbon Nanotubes, Yizheng Cao

Open Access Dissertations

One of the new engineering frontiers is the exploration of infrastructure materials with novel combinations of properties that break traditional paradigms. The goal of this study is to utilize two different nano-fibers, cellulose nanocrystals (CNCs) and carbon nanotubes (CNTs) to modify the nanoscale structures of cement composites and thereby improve the performance at the macro-level. This study also evaluates the mechanism behind the modification, since fiber bridging, the most common reinforcing mechanism for fiber-reinforced composites, cannot be simply applied because CNCs are too short to bridge cracks in cement composites. ^ The mechanical tests show an increase in the flexural …


Impact Of Anthropogenic Activities On Hydro-Climatological Variables, Kuk Hyun Ahn Oct 2014

Impact Of Anthropogenic Activities On Hydro-Climatological Variables, Kuk Hyun Ahn

Open Access Dissertations

The natural environment has been significantly affected by anthropogenic activities. Between 1700s and 2000s, agricultural land area had quintupled and the extent of natural vegetation was globally reduced by half. Furthermore many scientists argue that the recent rise in CO2 levels in the atmosphere is mainly due to anthropogenic activities. Anthropogenic activities may also play a crucial role in the change of the hydro-climatologic variables. In this study, impact of anthropogenic activities on two representative hydro-climatologic variables, temperature and streamflow, is investigated. The variations in temperature occur over larger spatial and time scale, and hence the United States is adopted …


A Nonlinear Interface Formulation For Frictional Contact, Layla K Amaireh Oct 2014

A Nonlinear Interface Formulation For Frictional Contact, Layla K Amaireh

Open Access Dissertations

Finite element simulations of contact problems often involve modeling the interaction of multiple bodies across a non-confirming interface. Non-Confirming Meshes (NCM) are typically associated with large sliding or adaptive refinement on one side of the interface to capture localized nonlinear behavior due to large deformations, damage and inelasticity. The use of NCMs, however, presents a number of numerical issues; the main challenge with such discretizations is to ensure compatibility of the kinematic and traction fields along the non-conforming interface. ^ The Enriched Discontinuous Galerkin Approach (EDGA) (Haikal and Hjelmstad,2010)addresses this challenge by implementing a local enrichment along with an interface …


Integrating Pro-Environmental Behavior With Transportation Network Modeling: User And System Level Strategies, Implementation, And Evaluation, Husain M. Abdul Aziz Oct 2014

Integrating Pro-Environmental Behavior With Transportation Network Modeling: User And System Level Strategies, Implementation, And Evaluation, Husain M. Abdul Aziz

Open Access Dissertations

Personal transport is a leading contributor to fossil fuel consumption and greenhouse (GHG) emissions in the U.S. The U.S. Energy Information Administration (EIA) reports that light-duty vehicles (LDV) are responsible for 61\% of all transportation related energy consumption in 2012, which is equivalent to 8.4 million barrels of oil (fossil fuel) per day. The carbon content in fossil fuels is the primary source of GHG emissions that links to the challenge associated with climate change. Evidently, it is high time to develop actionable and innovative strategies to reduce fuel consumption and GHG emissions from the road transportation networks. This dissertation …


Irrigation With Treated Wastewater: Potential And Limitations, Anne Dare Oct 2014

Irrigation With Treated Wastewater: Potential And Limitations, Anne Dare

Open Access Dissertations

As the world population increases and resources become more coveted, water emerges as a key component to global food security. The Middle East and North Africa (MENA) is among the driest regions in the world: containing just one percent of the world's freshwater resources. An increasing population creates greater quantities of wastewater and demands greater quantities of food, so an obvious connection arises. However logical wastewater reuse may be for bridging the irrigation supply-demand gap in this arid region, significant limitations prevent widespread adoption. The overall goal of this research is to take a holistic view of the limitations facing …


Camera Viewpoint Invariant Vehicular Traffic Segmentation And Classification, Jeffrey B. Flora Oct 2014

Camera Viewpoint Invariant Vehicular Traffic Segmentation And Classification, Jeffrey B. Flora

Electrical & Computer Engineering Theses & Dissertations

The goal of this intelligent transportation systems work is to develop a computer vision method that is view angle independent for segmenting and classifying vehicular traffic on highway systems. In order to achieve this goal, this work implements an algorithm for vehicle segmentation, feature extraction, and classification using the existing Virginia Department of Transportation (VDOT) infrastructure on networked traffic cameras. The VDOT traffic video is analyzed for vehicle detection and segmentation using an adaptive Gaussian mixture model algorithm. Speed estimation is performed using a single camera calibration. Size and shape features from morphological properties and texture features from histogram of …


Hydro-Climate Temporal Variations And Their Influences On Net Primary Production In A Eurasian Steppe Watershed, Xiaomin Yang Oct 2014

Hydro-Climate Temporal Variations And Their Influences On Net Primary Production In A Eurasian Steppe Watershed, Xiaomin Yang

Civil & Environmental Engineering Theses & Dissertations

Climate, which is the most important factor that influences Net Primary Productivity, has been detected changing all over the world. The confounding effects of step change invalidate the stationarity assumption of commonly used trend analysis methods such as the Mann-Kendall test technique, so previous studies have failed to explain inconsistencies between detected trends and observed large anomalies. In this research, by formulating a trend analysis approach that considers nonstationary due to step changes, trends and extreme occurrences of precipitation, temperature, and runoff in annual, seasonal, and monthly scales were analyzed in a mid-latitude Eurasian steppe watershed in northeast China, and …


Substation Bay Modeling And Seismic Sensitivity Study, Robert C.H. London Oct 2014

Substation Bay Modeling And Seismic Sensitivity Study, Robert C.H. London

Civil and Environmental Engineering Master's Project Reports

The performance of high voltage electrical substations during an earthquake significantly contributes to regional resilience by providing electrical power to public entities, businesses and homes following an earthquake. Utilities try to minimize the seismic impact by qualifying individual equipment, but rarely evaluate the interconnected substation bay as a whole. In this study, three detailed numerical models were developed using the seismic qualification reports of individual electrical equipment as basis for the components within 115kV, 230kV, and 500 kV substation bay systems. The substation bays were evaluated without interconnectivity of the components and with rigid bus connectivity between components. The models …


Investigation Of Closure Pour Elimination For Phased Construction Of Steel Girder Bridges, Terri R. Norton, Armando Shane Oct 2014

Investigation Of Closure Pour Elimination For Phased Construction Of Steel Girder Bridges, Terri R. Norton, Armando Shane

Nebraska Department of Transportation: Research Reports

No abstract provided.


The Bridge Newsletter Winter 2014, Missouri University Of Science And Technology Oct 2014

The Bridge Newsletter Winter 2014, Missouri University Of Science And Technology

The Bridge Newsletter

-Smart living
-Bodapati earns lifetime award
-TMS honors Myers
-Mays receives award for research


Fate Of Micropollutants During Pyrolysis Of Biosolids, John Ross Oct 2014

Fate Of Micropollutants During Pyrolysis Of Biosolids, John Ross

Master's Theses (2009 -)

Approximately 250 tons of organic micropollutants, including pharmaceuticals, antimicrobials, and hormones, are discharged to the environment during land application of wastewater biosolids annually. Reusing wastewater biosolids is vital to the sustainability of wastewater treatment, but current treatment processes do not remove micropollutants from biosolids in an efficient manner. Pyrolysis―the heating of biomass to temperatures between 400 and 800 °C under oxygen-free conditions―was proposed as a biosolids treatment process that could produce a beneficial soil amendment product, biochar, and remove micropollutants. The objective of this research was to determine the effect of pyrolysis temperature and residence time on the removal of …


Evaluation Of Collapse Indicators For Seismically Vulnerable Reinforced Concrete Buildings, Nicholas R. Skok Oct 2014

Evaluation Of Collapse Indicators For Seismically Vulnerable Reinforced Concrete Buildings, Nicholas R. Skok

Open Access Theses

Older reinforced concrete buildings can be prone to column shear and compression failures during earthquakes because of inadequate transverse reinforcement. Cities in seismic areas still have large inventories of older and potentially deficient buildings. To analyze every building and estimate its vulnerability in detail is costly. A simple method to rank quickly older buildings according to their seismic vulnerability is needed to help engineers prioritize the use of resources for rehabilitating the most vulnerable buildings.

Four indicators of building damage or collapse were evaluated using numerical analysis and prior data from building surveys: column index (Hassan & Sozen, 1997), R …


Evaluation Of Methods For Estimating Prestress Losses In High-Strength Structural Concrete, Mayren Yelitza Mata Carrillo Oct 2014

Evaluation Of Methods For Estimating Prestress Losses In High-Strength Structural Concrete, Mayren Yelitza Mata Carrillo

Open Access Theses

The purpose of this study was to evaluate the applicability of several current approaches used to estimate losses in prestressed concrete members with compressive strengths greater than 15ksi. The scope of the study focused on time-dependent losses for normal weight concrete bonded applications. The approaches evaluated were the PCI Design Handbook (2010) method, the AASHTO Specifications (2012) refined method, the PCI Bridge Design Manual (2003) time-dependent analysis using both the AASHTO (2012) and the PCI-BDM (2003) creep and shrinkage models, and a time-step method developed by Swartz (2010). The methods were compared to existing data on prestress losses from twenty-two …