Civil Engineering Commons^™

Observation Of Photovoltaic Effect And Single-Photon Detection In Nanowire Silicon Pn-Junction, Arief Udhiarto, Sri Purwiyanti, Daniel Moraru, Takeshi Mizuno, Michiharu Tabe

Makara Journal of Technology

We study nanowire silicon pin and pn-junctions at room and low temperature. Photovoltaic effects are observed for both devices at room temperature. At low temperature, nanowire pn-junction devices show their ability to detect single photon. This ability was not been observed for pin devices. Phosphorus-boron dopant cluster in the depletion region is considered to have the main role for single-photon detection capability. Fundamental mechanism of dopant-based single-photon detection in nanowire pn-junction is described in details.

Influences Of Surface Morphology Of Nanostructured Rutile Tio2 Nanorods/Nanoflowers As Photoelectrode On The Performance Of Dye-Sensitized Solar Cell, Mohd Khairul Bin Ahmad, Kenji Murakami

Makara Journal of Technology

Aligned Rutile TiO2 nanorods (r-TNRs) and TiO2 nanoflowers (r-TNFs) were successfully prepared by hydrothermal method. Using hydrochloric acid (HCl) as chelating agent and titanium butoxide (TBOT) as precursor, aligned r-TNRs with r-TNFs were successfully growth onto fluorine-doped tin oxide (FTO) with different morphologies. The influences of surface morphologies to the rutile based Dye-sensitized solar cell (DSC) efficiency are discussed. The highest lightto- electric energy conversion efficiency, 1.80% is achieved using different concentration under simulated solar light illumination of 100 mWcm-2 (1.5 AM).

Improvement In Performance Of Zno Based Dsc Prepared By Spraying Method, Rangga Winantyo, Devinda Liyanage, Kenji Murakami

Makara Journal of Technology

This paper reports the effect of TiCl4 on the performance of ZnO based DSC. ZnO was used due to its stability against photo-corrosion and photochemical properties similar to TiO2. Thin films of nanocrystalline ZnO were deposited on transparent conducting oxide glass using spray method. The ZnO films were treated using TiCl4. The cell’s efficiency was found to be 2.5% with TiCl4 post-treatment and 1.9% without TiCl4 post-treatment.

Determining The Air Gap Length Of An Axial Flux Wound Rotor Synchronous Generator, Abdul Multi, Iwa Garniwa, Uno Bintang Sudibyo

Makara Journal of Technology

The air gap length of the designed axial flux wound rotor (AFWR) synchronous generator is determined properly according to the design parameters. One of the distinct advantages of an axial flux (AF) machine is its adjustable air gap. An AF generator’s performance might be controlled by adjusting its air gap. The designed generator has a smallscale capacity that has 1 kW, 380 V, and 50 Hz. The windings are laid into slots made from laminated core. The slots are carved in the face of the stator and rotors. The generator has a single-double-sided slotted wound stator sandwiched between twin rotors. …

Production Optimization For Plan Of Gas Field Development Using Marginal Cost Analysis, Suprapto Soemardan, Widodo Wahyu Purwanto, Arsegianto Arsegianto

Makara Journal of Technology

Gas production rate is one of the most important variables affecting the feasibility plan of gas field development. It take into account reservoir characteristics, gas reserves, number of wells, production facilities, government take and market conditions. In this research, a mathematical model of gas production optimization has been developed using marginal cost analysis in determining the optimum gas production rate for economic profit, by employing the case study of Matindok Field. The results show that the optimum gas production rate is mainly affected by gas price duration and time of gas delivery. When the price of gas increases, the optimum …

Passive Stormwater Samplers For Sampling Highway Runoff From Bmps: Feasibility Studies, Mitchell R. Klein

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Pollution from highway stormwater runoff has been an increasing area of concern within the environmental field. To respond to the need for reduced contamination within runoff many Best Management Practices (BMPs) have been implemented. One difficult aspect of BMPs is monitoring their effectiveness along with determining effluent concentrations. The current methods for stormwater sampling include sending technicians or installing an auto-sampler to collect either grab or composite samples. These methods become costly, cumbersome and infeasible due to the potentially large amount of BMPs across a region and the irregularity and difficulty of predicting storms. Passive samplers have proven themselves as …

Effect Of Lightweight Aggregate Moisture Content On Internally Cured Concrete, Casey Jones

Graduate Theses and Dissertations

Putting an end to the rapid deterioration of concrete structures in the United States will only occur through the introduction of better materials and construction methods. The American Society of Civil Engineers (ASCE) reports the overall condition of concrete bridges in the United States to be a "C+". Though better than other areas of the infrastructure, there is still room for improvement in concrete bridges. One major area that may be improved is that of the concrete bridge deck. The bridge deck is comprised of the actual driving surface. It is subject to many deterioration mechanisms including freeze/thaw cycles, de-icing …

Measurement Of Emissions From A Passenger Truck Fueled With Biodiesel From Different Feedstocks, Natchanok Pala-En, Melanie L. Sattler, Brian Dennis, Victoria Chen, Rachel L. Muncrief

Civil Engineering Faculty Publications - Archive

Biodiesel has generated increased interest recently as an alternative to petroleum-derived diesel. Due to its high oxygen content, biodiesel typically burns more completely than petroleum diesel, and thus has lower emissions of hydrocarbons (HC), carbon monoxide (CO), and particulate matter (PM). However, biodiesel may increase or decrease nitrogen oxide (NOx) and carbon dioxide (CO2) emissions, depending on biodiesel feedstock, engine type, and test cycle. The purpose of this study was to compare emissions from 20% blends of biodiesel made from 4 feedstocks (soybean oil, canola oil, waste cooking oil, and animal fat) with emissions from ultra low sulfur diesel (ULSD). …

Social Capital And Walkability As Social Aspects Of Sustainability, Shannon Rogers, Kevin Gardner, Cynthia Carlson

Civil Engineering Faculty Publications

The concepts of sustainability and sustainable development are frequently described as having three main components, sometimes referred to as the three pillars or the triple bottom line: environmental, economic, and social. Because of an historical focus in the sustainability field on correcting environmental problems, much consideration has been given to environmental issues, especially how they interface with economic ones. Frequently mentioned but rarely examined, the social aspects of sustainability have been considered the weakest and least described pillar. After a brief review of existing concepts and theories, this paper uses a case study approach to examine the third pillar more …

Statistical Model For Estimating Carbon Dioxide Emissions From A Light-Duty Gasoline Vehicle, Benjamin Nmai Afotey, Melanie L. Sattler, Stephen P. Mattingly, Victoria Chen

Civil Engineering Faculty Publications - Archive

No abstract provided.

Flexural Strength Reliability Of Visually Graded Southern Pine Dimensional Lumber, Mengyu Yang

All Theses

The reference design values published in the National Design Specification (NDS) for Wood Construction are derived from full-scale testing of lumber samples performed in the 1980s. This testing program is commonly known as the In-GradeTest Program. Selective annual sample tests of visually graded Southern Pine lumber from 1994 to 2010 revealed an overall decreasing trend in the mechanical properties. Because of this alarming observation, a new round of full-scale In-Grade test of visually graded Southern Pine was initiated in 2010. The new test data indicated significant reductions in certain design values published in the current design code (2005 NDS). …

Robust Design Optimization: Ensuring Robustness Against Uncertainty In Structural Design, Zhifeng Liu

All Dissertations

In structural design, if robustness is overlooked in design process, the acquired design is likely to have large variation in its performance due to uncertainties. In that there is no design specification that explicitly considers the robustness against such uncertainties, this dissertation elucidates design methodologies for use in selecting the optimal design parameters to minimize the effect of the hard to reduce or irreducible uncertainties on structural performance, i.e., maximizing the robustness. However, due to limited resources, structural designs are also constrained by available resources and budget. Consequently, in that a tradeoff relationship exists between the robustness and cost (i.e. …

Risk Assessment Model For Pipe Rehabilitation And Replacement In A Water Distribution System, Jan C. Devera

Master's Theses

The efficient delivery of potable water for a community through its distribution system has historically been the backbone of nearly all metropolitan developments. Much of these systems are comprised of pipe networks made of various materials including concrete, iron, PVC, and even steel. As these communities expand and urbanize, water demand and population density simultaneously increase. This develops higher strains and stresses in the community‟s water distribution network causing pipes to corrode, crack, or rupture prematurely while in service. As a result, the deterioration of water distribution systems in growing cities is increasingly becoming a major concern for our nation. …

Phosphorus Removal From Ebpr Sludge Dewatering Liquors Using Lanthanum Chloride, Aluminum Sulfate And Ferric Chloride, Michael Strileski

UNLV Theses, Dissertations, Professional Papers, and Capstones

In wastewater treatment, enhanced biological phosphorus removal (EBPR) is becoming an increasingly popular alternative to chemical precipitation (CP) because of its lower costs and reduced sludge production. However, downstream solids handling processes such as digestion, sludge storage and dewatering promote an undesirable release (i.e. secondary release) of polyphosphate that was stored within EBPR sludge. Released phosphate is recycled to the head of the plant with the liquors of sludge dewatering processes. The concentration of phosphate in recycle streams from EBPR systems can be one to two orders of magnitude higher than the influent phosphorus concentration entering the EBPR system. Plants …

Development Of A Rating System To Measure The Vulnerability Of Residential Homes To Natural Hazards, Corey Cattano

All Dissertations

Hurricanes and tropical storms continue to damage the United States coastline where population migration increases and tourism thrives. Extended dry spells, high winds, and hot summers in the Mountain and Pacific West regions promote ideal conditions for seemingly uncontrollable wildfires. Additionally, the increased frequency of unstable climate conditions foretells signs of Mother Nature not letting up. With recent events such as Superstorm Sandy and the Waldo Canyon wildfires in mind, there is a strong need to improve hazard mitigation techniques in residential homes and encourage resilient building methods. Research within this field is challenging due to the lack of descriptive …

Miniature Concrete Prism Test - A New Test Method For Evaluating The Asr Potential Of Aggregates, The Effectiveness Of Asr Mitigation And The Job Mixture, Enamur Latifee

All Dissertations

Existing test methods to characterize ASR potential of aggregates and mitigation ability of supplementary cementing materials such as the Accelerated Mortar Bar Test (AMBT) and the Concrete Prism Test (CPT) are widely accepted in the industry. Although, the AMBT is a rapid test, the results from this test can be unreliable, particularly with certain types of aggregates. The CPT is considered as a more reliable test; however, the duration of this test method renders it impractical for routine usage in the industry to screen deleterious materials or inefficient ASR mitigation measures. This research presents a new test method-Miniature Concrete Prism …

Volatile Organic Compound Emissions From Surface Coating Facilities: Characterization Of Facilities, Estimation Of Emission Rates, And Dispersion Modeling Of Off-Site Impacts, Annabrabha Athappan, Sulak Sumitsawan, Roja Haritha Gangupomu, Ketwalee Kositkanawuth, Parthen Parikh, Benjamin Nmai Afotey, Neelesh Sule, Sahithi Raj Kalidindi, Melanie L. Sattler, Yvette Pearson Weatherton

Civil Engineering Faculty Publications - Archive

Surface coating facilities are major sources of volatile organic compounds (VOCs) in urban areas. These VOCs can contribute to ground-level ozone formation, and many are hazardous air pollutants (HAPs), including xylene, ethylbenzene, and toluene. This project was conducted in order to provide information for updating the Texas Commission on Environmental Quality (TCEQ), USA, permit by rule for Surface Coating Facilities. Project objectives were: 1) To develop a database of information regarding surface coating facilities in Texas; 2) To estimate maximum emission rates for various VOC species from surface coating facilities in Texas; 3) To conduct dispersion modeling to estimate off-site …

Accuracy Analysis Of Parallel Method Based On Non-Overlapping Domain Decomposition Method, Moonho Tak, Yooseob Song, Hye-Kwan Jeon, Taehyo Park

Civil Engineering Faculty Publications

In this paper, an accuracy analysis of parallel method based on non-overlapping domain decomposition method is carried out. In this approach, proposed by Tak et al.(2013), the decomposed subdomains do not overlap each other and the connection between adjacent subdomains is determined via simple connective finite element named interfacial element. This approach has two main advantages. The first is that a direct method such as gauss elimination is available even in a singular problem because the singular stiffness matrix from floating domain can be converted to invertible matrix by assembling the interfacial element. The second is that computational time and …

Diffusivity And Sorptivity Of Berea Sandstone Determined Using Neutron Radiography, M. Kang, Chu-Lin Cheng, H. Z. Bilheux, Michael J. Gragg, D. M. Wright, J. M. Lamanna, J. Horita, J. M. Warren

Civil Engineering Faculty Publications

Neutron radiography is increasingly being used to study the dynamics of water movement in variably saturated porous media. It has been applied to visualize water imbibition in both natural and engineered materials, including soil, rock, brick, concrete, and glass. The sorptivity, S, and unsaturated diffusivity, D(θ), are important parameters for describing water movement under partially saturated conditions. Estimates of S and D(θ) have been obtained using a variety of techniques, including neutron imaging. However, we could find no previous reports of such measurements for the Berea sandstone, regardless of the method employed. Berea sandstone is a widespread, …

Forward Prediction Of Height-Averaged Capillary Pressure–Saturation Parameters Using The Bc-Vg Upscaler, Chu-Lin Cheng, Edmund Perfect, R. T. Mills

Civil Engineering Faculty Publications

There is ongoing interest in approaches for upscaling point (e.g., pixel or voxel scale) measurements of soil hydraulic properties to predict column-scale behavior in the laboratory, or even field-scale processes. We have developed the BC-vG Upscaler for estimating the height-averaged capillary pressure–saturation relationship, , for a given porous medium based on equations used in the TrueCell program. Whereas TrueCell inversely estimates point Brooks and Corey (BC) equation parameters from  data, the BC-vG Upscaler uses point BC parameters as inputs for the forward prediction of height-averaged van Genuchten (vG) parameters. The BC-vG Upscaler was verified using previously published, independent point and …

A New Framework For Flooding Control In Regulated River Systems, Elizabeth Akemi Kanashiro

Boise State University Theses and Dissertations

This thesis presents a case study on the application of a dynamic framework for the intelligent control of flooding in the Boise River system in Idaho. This framework couples a robust and numerically efficient hydraulic routing approach with the popular multi-objective, non-dominated Sorting Genetic Algorithm II (NSGA-II). The novelty of this framework is that it allows for controlled flooding when the conveyance capacity of the river system is exceeded or is about to exceed. Controlled flooding is based on weight factors assigned to each reach of the system depending on the amount of damage that would occur should a flood …

Calibration Of Microscopic Traffic Flow Models Considering All Parameters Simultaneously, Victor Hugo Molano Paz

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study proposes a methodology to calibrate microscopic traffic flow simulation models. The proposed methodology has the capability to calibrate simultaneously all the calibration parameters as well as demand patterns for any network topology. These parameters include global and local parameters as well as driver behavior and vehicle performance parameters; all based on multiple performance measures, such as link counts and speeds. Demand patterns are included in the calibration framework in terms of turning volumes.

A Simultaneous Perturbation Stochastic Approximation (SPSA) algorithm is proposed to search for the vector of the model‟s parameters that minimizes the difference between actual and …

Implementation Of Integrated Project Delivery On Department Of Navy Military Construction Projects, Christopher S. Lee

UNLV Theses, Dissertations, Professional Papers, and Capstones

The concept of the project delivery system refers to the overall processes by which a project is designed, constructed, and/or maintained. There are many different types of project delivery systems to fit particular situations involving the owner and his intended project. The project delivery system is what establishes the framework that enables a construction project to be developed and ultimately executed.

The construction industry has observed that projects (both private and public) frequently suffer from factors such as adversarial relationships, low roductivity, high inefficiency and rework, frequent contractual disputes concerning who was at fault, and lack of innovation. Not only …

Effect Of Differential Movement Of Straight Reinforcing Bars During Early Age Curing On The Bond Strength, Tyler Andrews

All Theses

As the nation's infrastructure continues to age, the number of structural deficiencies is rising. Accordingly, there is a great need and desire to replace these failing components in a quick and efficient fashion. Prefabricated elements for structures such as bridges and parking decks are commonly implemented in this process in order to save both time and money. These prefabricated elements are often subjected to moving live loads during construction and repair which, consequently, result in differential movements occurring across the joints connecting the elements of these structures. Potential reductions in joint capacity, joint stiffness, and structural durability are the byproducts …

Data Driven, Performance Based Parking Management In A University Setting, Brian Maleck

All Theses

With university enrollment increasing, campuses are becoming under increased strain for parking. More students results in more cars on an already stressed parking infrastructure. In many instances, university parking management offices are being asked to accommodate this increase in parking without the construction of new parking infrastructure. In order to accommodate these demands, better parking management is required.
This research develops a framework to evaluate current parking management practices and pinpoint methods to improve upon current practices. The framework is generalized for use by any size and type of university. Clemson University's campus in Clemson, SC was used as a …

Probabilistic Back Analysis Of Geotechnical Systems, Lei Wang

All Theses

This thesis is aimed at applying the probabilistic approaches for back analysis of geotechnical systems. First, a probabilistic back-analysis of a recent slope failure at a site on Freeway No. 3 in northern Taiwan is presented. The Markov Chain Monte Carlo (MCMC) simulation is used to back-calculate the geotechnical strength parameters and the anchor force. These inverse analysis results, which agree closely with the findings of the post-event investigations, are then used to validate the maximum likelihood method, a computationally more efficient back-analysis approach. The improved knowledge of the geotechnical strength parameters and the anchor force gained through the probabilistic …

An Analysis Of A Missing Design Concept For Sustainable Buildings: Addressing The Safety And Health Of The Construction Worker, Christopher Almond

All Theses

Construction work is inherently dangerous. The 2010 U.S. Bureau of Labor Statistics show the construction industry had the most fatal injuries of all industry sectors, 17%. U.S. regulations place the responsibility for construction safety on the construction contractor. However, owners and designers have the potential to affect the safety of the construction workforce. Owners have gotten more involved in promoting the safety and health of construction workers in recent years; however, studies show that the safety and health of the construction workforce is not typically considered by designers.
The Naval Facilities Engineering Command (NAVFAC) - the U.S. Navy's systems command …

Impact Of Channel Conditions On Existing Scour Measuring Instruments, Md Nasimul Hoque Chowdhury

All Theses

Scour around bridge piers and abutments, is the prominent reason for bridge failures. Bridge failures have substantial effects on economy and human lives. About 60% of the total bridge failures in U.S. can be attributed to scour. In the past, scour has been responsible for several million dollars in bridge repair cost. Given the threat to the bridge infrastructure due to scour, the U.S. Federal Highway Administration has proposed several countermeasures to reduce the impact of bed degradation. One of these countermeasures that is particularly relevant during peak flow periods is the real-time scour monitoring. Scour monitoring involves real-time data …

Application Of Parameter Estimation And Calibration Method For Car-Following Models, Md Rahman

All Theses

Both safety and the capacity of the roadway system are highly dependent on the car-following characteristics of drivers. Car-following theory describes the driver behavior of vehicles following other vehicles in a traffic stream. In the last few decades, many car-following models have been developed; however, studies are still needed to improve their accuracy and reliability.
Car-following models are a vital component of traffic simulation tools that attempt to mimic driver behavior in the real world. Microscopic traffic simulators, particularly car-following models, have been extensively used in current traffic engineering studies and safety research. These models are a vital component of …

Corrosion Activity In Precast Concrete Elements And Cementitious Closure Pours, Shabi Abbas Udaipurwala

All Theses

The use of prefabricated elements in the construction of highway bridges has been a common practice in the United States since 1950s. Precast concrete adjacent box beam girder bridges are quite popular given that the precast elements not only have structural capacity to span across the supports, but also form the bridge deck. These bridges have generally performed well during the initial years after construction, but recent failures in Pennsylvania and Indiana have aroused a nationwide alarm to investigate the causes of failure and find solutions to repair these bridges or develop design for new replacement bridges. It was found …