Civil and Environmental Engineering Commons^™

Dynamic Behavior Of Operational Wind Turbines Considering Aerodynamic And Seismic Load Interaction, Mohammad-Amin Asareh

Doctoral Dissertations

"With the advancements in the wind energy production industry, the demand for a cost effective and safe design of wind turbine structures is growing rapidly. The wide deployment of wind turbines in locations with high seismic hazard has lead engineers to take into account a more comprehensive seismic design of such structures. In response to the need for a computational tool that can perform coupled simulations of wind and seismic loads, a seismic module has been developed for the publicly available National Renewable Energy Laboratory (NREL) code, FAST, at the first step of this research. This achievement allows engineers working …

Reliability-Based Optimization Design Of Geosynthetic Reinforced Embankment Slopes, Michelle (Mingyan) Deng

Doctoral Dissertations

"This study examines the optimization design of geosynthetic reinforced embankment slopes (GRES) considering both economic benefits and technical safety requirements. In engineering design, cost is always a big concern. To minimize the cost, engineers tend to seek an optimal combination of design parameters among the considered alternatives while ensuring the optimal solution is safe. Reliability-based optimization (RBO) is such a technique that provides engineers the optimal design with the minimum cost while all technical design requirements are satisfied. The research goal of this study is to implement a mathematical formulation algorithm of the RBO technique in GRES design. To achieve …

Performance Analysis And Modelling Of Hybrid Photovoltaic-Thermal Solar Panels, Nicole C. Annis

Doctoral Dissertations

A photovoltaic-thermal (PVT) panel was constructed, tested, and modelled using both MATLAB and TRNSYS. During the experimental testing, which took place on the Missouri University of Science and Technology campus in Rolla, Missouri; two identical PVT panels were tested alongside two PV panels to gather an electrical baseline for comparison. Approximately 69 days’ worth of data were of data were collected during the summer of 2014. The PV electrical, PVT electrical, PVT thermal and PVT combined (electrical and thermal) efficiencies were 3.5-5.6%, 3.4-5.4%, 20.9-11.6%, and 24.3-17.0%, respectively.

A MATLAB program was developed using existing equations for one-dimensional, quasi-steady model of …

Performance Characteristics Of Polyethylene Terephthalate (Pet) Modified Asphalt, Matthew D. Earnest

College of Graduate Studies: Theses & Dissertations

Polyethylene terephthalate (PET) plastic is utilized primarily in food and beverage packaging. Although a portion of waste PET is recycled, the majority of the waste is buried in landfills. Therefore, the use of ground PET particles in asphalt may provide an environmentally friendly solution for the disposal of large quantities of PET waste. This study evaluated the performance of PET as an asphalt modifier with both asphalt binder and asphalt mixture testing. The binder testing was conducted on wet process blends produced with a high shear mixer at PET contents of 5, 10, and 15 percent by weight of the …

Ammonia Oxygen Demand Determination For The Design Of An Oxygenation System In A Water Supply Reservoir, Armond Jenkins

College of Graduate Studies: Theses & Dissertations

The Occoquan Reservoir is a eutrophic reservoir that is part of an indirect potable reuse system. To protect the reservoir water quality, a high quality nitrified product water from a water reclamation facility and an oxygenation system are used during periods of thermal stratification to prevent the onset of anaerobic conditions above the sediments. During the stratified warmest months of the year, oxygen depletion rates exceed nitrate and artificial oxygen supply rates near the dam resulting in ammonia accumulation in the water column. Field observations and laboratory experiments revealed that sediment ammonia release rates ranged from 170-542 mg/m²∙day. …

Statistical Approach To Design For Fall Prevention In Construction, Kyunghwan Kim

Wayne State University Theses

During the past decades, the construction industry has been considered as one of the most vulnerable field to work-related injuries and fatalities, and fall accidents are the leading causes accounting for about one-third of the total fatal injuries happened in construction. Furthermore, more than 30% of fall fatal cases occurred in the projects under $ 300K in Korea where construction workers' safety and health are not usually considered as top priorities because the contractors, who are normally small sized construction firms or self-employed, do not have safety budget to deal with construction workers' safety.

In this respect, this study focused …

Autotrophic Ammonia Oxidation Activity Of Ammonia Oxidizing Archaea And Bacteria In Recirculating Aquaculture System, Iftita Rahmatika

Chulalongkorn University Theses and Dissertations (Chula ETD)

Ammonia oxidation is the important biological step in nitrogen removal in aquaculture system of shrimp production. This process is driven by the ammonia oxidizing bacteria (AOB) and the newly discovered ammonia oxidizing archaea (AOA). In this study, the abundances, communities and autotrophic ammonia oxidation activity of AOA and AOB in the recirculating aquaculture system (RAS) were investigated. Bioballs were sampled from the low and high salinity RAS (0 and 20 PPT, respectively). The abundance of AOA and AOB amoA genes were monitored for 5 months with qPCR. The abundance of AOA amoA genes was 2-700 times higher than AOB in …

การประเมินคาร์บอนฟุตพริ้นท์องค์กรและวิเคราะห์แนวทางการลดก๊าซเรือนกระจกที่เหมาะสม กรณีศึกษาโรงงานปิโตรเคมีขั้นกลางในประเทศไทย, จิราภรณ์ ธรรมเนียมอินทร์

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้มีวัตถุประสงค์เพื่อประเมินคาร์บอนฟุตพริ้นท์องค์กรและประเมินแนวทางการลดก๊าซเรือนกระจก พร้อมทั้งเสนอแนวทางการลดก๊าซเรือนกระจกที่เหมาะสมกับโรงงานในกลุ่มอุตสาหกรรมปิโตรเคมีขั้นกลางในประเทศไทย งานวิจัยได้ศึกษาโรงงานตัวแทนทั้งหมด 6 โรงงาน ครอบคลุมผลิตภัณฑ์ 9 ผลิตภัณฑ์ (เอทิลีนออกไซด์ เอทิลีนไกลคอล ไวนิลคลอไรด์มอนอเมอร์ คิวมีน ฟีนอล แอซีโทน บิสฟีนอล เอ อีพิคลอโรไฮดริน และกรดเทเรฟทาลิกบริสุทธิ์) รวบรวมข้อมูลย้อนหลัง 3 ปี ตั้งแต่ พ.ศ.2555-2557 และแบ่งแหล่งกำเนิดก๊าซเรือนกระจกออกเป็น 2 ประเภท คือ การปล่อยก๊าซเรือนกระจกทางตรงและทางอ้อม ผลการวิจัยพบว่าขนาดคาร์บอนฟุตพริ้นท์องค์กรของโรงงานตัวแทน มีค่าอยู่ในช่วง 70,253-570,307 t CO2eq ต่อปี ส่วนใหญ่มาจากการปล่อยก๊าซเรือนกระจกทางอ้อม โดยมีการปล่อยก๊าซเรือนกระจกสูดสุดมาจากการใช้ไฟฟ้าคิดเป็นร้อยละ 40 ของการปล่อยเรือนกระจกทั้งหมด รองมาด้วยการใช้ไอน้ำและการปล่อยคาร์บอนไดออกไซด์จากปฏิกิริยาในกระบวนการผลิต ค่าความเข้มคาร์บอนมีค่าอยู่ระหว่าง 0.269-1.101 t CO2eq/t product มีค่าความเข้มคาร์บอนเฉลี่ยเท่ากับ 0.425 t CO2eq/t product จากการวิเคราะห์มาตรการอนุรักษ์พลังงาน พบว่า มีศักยภาพในการลดปริมาณก๊าซเรือนกระจกได้ 166,820 t CO2eq คิดเป็นร้อยละ 3.89 ของการปล่อยก๊าซเรือนกระจกทั้งหมดของกลุ่มโรงงานตัวแทน โดยมาตรการประหยัดไอน้ำเป็นมาตรการที่สามารถลดการปล่อยก๊าซเรือนกระจกได้สูงสุด คิดเป็นร้อยละ 82.89 ของมาตรการที่ดำเนินการทั้งหมด สำหรับแนวทางการลดก๊าซเรือนกระจกมีความเหมาะสมและสามารถนำไปปรับใช้กับกลุ่มอุตสาหกรรมปิโตรเคมีขั้นกลาง แนะนำทั้งหมด 5 แนวทาง ประกอบด้วย (1) การเปลี่ยนแหล่งพลังงานทางอ้อม (2) การเพิ่มประสิทธิภาพการใช้พลังงานจากมาตรการอนุรักษ์พลังงาน (3) การจัดการก๊าซคาร์บอนไดออกไซด์จากปฏิกิริยาในกระบวนการผลิต (4) การปรับปรุงและพัฒนาเทคโนโลยีในกระบวนการผลิต และ (5) การปรับเปลี่ยนการใช้สารทำความเย็น

A Study Of Uplift Capacity Of Pipeline In Soils, Khamnoy Kounlavong

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis aims to analyze the uplift capacity of a burial pipeline in two types of soil namely cohesionless soils and cohesive-frictional soils. Finite element analysis with two dimensional plain strain condition were employed to model and determine the limit load of this problem. Cohesionless and cohesive-frictional soils were model as Mohr-coulomb materials in the drained condition while a pipeline was modeled as plate element with an elastic material with high axial and bending stiffness to ensure its rigid behavior. Parametric studies of cohesionless soils and cohesive-frictional soils were performed to study effects of dimensionless variables, including 1) embedment depth …

Numerical And Experimental Studies Of Undercut Slopesinclined Along A Bedding Plane, Rithy Ouch

Chulalongkorn University Theses and Dissertations (Chula ETD)

Slope failures along a bedding plane were critical issues and mostly happened in an open pit mining project such as the Mae Moh Mine, Thailand. The prediction of maximum width to which the slope remains stable after an excavation process is required. The aim of this research is to investigate the stability and failure mechanisms of undercut slopes with and without shear pins resting on a bedding plane by means of physical and numerical models. Physical models of slip tests and undercut slopes were made of the humid silica sand No. 6 with 10% of water content and rested on …

Alternative Fatigue Cracking Resistance Assessment Criteria Of Asphalt Mixtures With Overlay Tester, Alejandro Miramontes

Open Access Theses & Dissertations

The accumulation of damage due to cracking of hot mix asphalt (HMA) layers under repeated loading along with the climatic effects is known as fatigue cracking. The Overlay Tester (OT) has been implemented or considered by several highway agencies as an index to evaluate the cracking susceptibility and resistance to cracking of asphalt mixtures in the laboratory. The performance indicator used to measure the quality of the HMA mixes is the number of cycles that a specimen may resist during the test until the crack appears and fully propagates to the top of the specimen. The repeatability of the number …

Design Optimization And Optical Characterization Of A High Temperature Solar Receiver, Samia Afrin

Open Access Theses & Dissertations

Concentrated solar power (CSP) is a fast forwarding technology in power generation sector because of its' competitive price, abundance in nature and the most important fact is its' energy storage capability. Among the four types of available CSP technology, central receiver has more potential concerning with high temperature, power block efficiency and levelized cost of energy (LCOE). Other than conventional type of receiver design, the concept of this work is very particular in a sense of its design novelty.

National Renewable Energy Laboratory (NREL) come up with a new concept of high temperature solar receiver called near black body (NBB) …

Salt And Mineral Recovery From High Salinity Waters, Osvaldo Alejandro Broesicke

Open Access Theses & Dissertations

Natural salt springs in the Salt Fork Basin in Crosby County, Texas, result in the natural salt pollution of the Brazos River, rendering it unusable for most potable purposes. Previous research indicates that by intercepting the source of the pollution, water quality of the Brazos River can be greatly improved. This paper investigates and assesses two strategies for salt and mineral recovery using natural brine collected from the Salt Fork Basin, the first of which is presented in a separate work.

The research described in this paper evaluates the potential of a desulfation, soda-caustic softening, acidification/decarbonation, and evaporation process to …

Moisture Susceptibility Of Dense Graded Asphalt Concrete Using Cyclic Moistue Induced Stress Tester, Sarvesh Dip Dhakal

Open Access Theses & Dissertations

Moisture damage in asphalt concrete causes loss in mechanical properties of asphalt material due to the presence of moisture in its microstructures in a liquid or a vapor state. Some of the common types of distress observed in asphalt pavements due to moisture damage are stripping (separation of asphalt binder and aggregate), raveling (dislodgement of aggregate particles in asphalt mixture from surface), and hydraulic scour (a process that occurs on a saturated surface by which the pavement material is eroded due to dynamic action of tires in the presence of water). This Thesis focuses on the research on the effects …

Comparison Of Bicycle Transportation Systems In El Paso And Prague, Jose C Hernandez

Open Access Theses & Dissertations

Bicycle transportation infrastructure has an important role in bicycle transportation mode. Every year there are hundreds of accidents where bicyclist are involve, because there is not a good infrastructure for bicycles in the roads bicyclists have a potential risk. One of the main purposes is maintain the bicyclistsâ?? safety in the roads to attract more people to use this eco-friendly transportation mode. The goal of this Thesis is compare the bicycle infrastructure in two different countries, United States and Czech Republic. The history and the main terminology are described in firsts chapters. Based on law and regulations, design criteria and …

A Stochastic Approach For Pavement Condition Projections And Budget Needs For The Mtc Pavement Management System, Rafael Arturo Ramirez Flores

Open Access Theses & Dissertations

Pavement management decision-making is the most important task for officials in transportation agencies, who develop maintenance and rehabilitation programs. Information about historical pavement network performance is needed for decision-making; pavement management systems (PMS) provide means to organize road network data to improve the pavement network condition. PMS have prediction performance models to forecast the future condition of the pavement networks with information required for decision-making; these models can be deterministic or probabilistic. Pavement performance deterministic models are commonly used in PMS, but they do not consider the uncertainty in forecasting pavement performance. Pavement performance depends on many random factors like …

Recovery Of Nutrient Nitrogen From Municipal Wastewater Residuals By Gas Membrane Separation, Evelyn Rios

Open Access Theses & Dissertations

There are relatively high amounts of ammonia returned to the headworks of a municipal wastewater plant that are extracted from the dewatering process. This ammonia load contributes to a significant oxygen demand in the secondary treatment, requiring greater air blower energy costs. This goal of this research was to evaluate the feasibility of the recovery of an ammonium sulfate product from belt press filtrate. The objectives of this research were to: (1) analyze wastewater treatment average monthly data flows and constituents with respect to ammonia nitrification, (2) the evaluate the technical performance of a two sage gas-separation membrane for recovering …

Performance Life Of Various Hot Mix Asphalt Mixtures In Texas, Danniel David Rodriguez

Open Access Theses & Dissertations

Typically, pavement engineers in subjectively estimate the service lives of various hot-mix asphalt (HMA) mixtures as part of the life-cycle cost analysis considering the staged design and rehabilitation of flexible pavements. This study proposes the performance lives for the various dense-graded (conventional) mixtures, stone-matrix asphalts (SMA), permeable friction courses (PFC), performance design mixtures and other mixtures placed in Texas. A necessary and significant aspect of the approach involved data mining and merging several pavement management databases (Letting Database, DCIS and PMIS) to obtain mixture longevity data along with historical PMIS information. The product of the linking process resulted in the …

Accuracy And Precision Evaluation Of Traffic Speed Pavement Deflection Devices, Jorge Velarde

Open Access Theses & Dissertations

Pavement structural adequacy is considered an important aspect of the pavement management activities and can be incorporated by using surface pavement deflections. Continuous deflection technology, which has been around for several years, can potentially supplant single point deflection measurements provided by the Falling Weight Deflectometer (FWD). Previous studies have evaluated the traffic speed deflection devices (TSDD) accuracy and precision by comparing their results with FWD measurements. Although appropriate correlations and indices to compensate for the differences in load have been made, a direct comparison under the same loading conditions has not been reported in the literature.

The goal of this …

Dispersion Modeling Of Nitrogen Dioxide (No2) And Fine Particulate Matter (Pm2.5) From Backup Generators At Data Centers In Prineville, Oregon, Brooke E. Harmon

Civil and Environmental Engineering Master's Project Reports

As our society becomes increasingly dependent on digital communication (e.g., social media and email) and computerized storage (e.g., digitized medical records and government documents), tech giants such as Google, Facebook, and Apple are constructing and managing an increasing number of massive Internet data centers. These data centers house a network’s most critical systems and are vital to the continuity of daily operations. Requiring as much electricity as a medium size city, data centers rely on complex auxiliary power systems to prevent disruption to service. These backup systems consist of tens of multi-megawatt diesel-powered generators that release combustion byproducts, including over …

Pushover Analysis Of Retrofitted Reinforced Concrete Buildings, Hamidreza Nahavandi

Civil and Environmental Engineering Master's Project Reports

For the past decade or more, the structural engineering profession has been using the nonlinear static procedure (NSP) or pushover analysis. Modeling for such analysis requires the determination of nonlinear properties of each component in the structure, quantified by strength and deformation capacities, which depend on the modeling assumptions. Pushover analysis is carried out for either user-defined nonlinear hinge properties or default-hinge properties, available in some programs based on the FEMA-356 such as SAP2000. While such documents provide the hinge properties for several ranges of detailing, programs may implement averaged values. In the realm of retrofitting of existing structures, few …

Dynamic Effect Of Light And Turbulence On Algal Photosynthetic Rate: A Water-Quality Model, Andres R. Rivas

Civil and Environmental Engineering Master's Project Reports

Several studies provide evidence that algal photosynthetic rates depend on various changing factors such as light attenuation, temperature, and nutrient limitation (Chapra, 1997). However, recent papers show that turbulence and photosynthetic rate dynamics is also important (Ross, 2006). In this study, the photosynthetic rate model used is the one proposed by Chapra (1997), where it depends directly on temperature, nutrient and light limitation factors. At the same time, the effect of turbulence or random-walk of algae particles in the water column was also introduced in this model. To account for this factor, the model added was that proposed by Ross …

Properties Of Microcement Mortar With Nano Particles, Narasimha Reddy Alimeneti

Civil Engineering Theses - Archive

Carbon nanotubes (CNT) and Carbon nanofibers (CNF) are one of the toughest and stiffest materials in the world presently with extreme properties yet to be discovered in terms of elastic modulus and tensile strength. Due to the advanced properties of these materials they are being used in almost all fields of science at nanolevel and are being used in construction industry recently for improvement of material properties. Microcement is fine ground cement which as half the particle size of ordinary Portland cement. In this research the behavior of cement mortar of micro cement with the addition of nanoparticles is studied.Due …

Effect Of Preformed Chloramines And Chlorine To Ammonia Ratio On The Formation Of N-Nitrosodimethylamine (Ndma) In Trwd East Texas Raw Water Delivery System, Khidir Hamad

Civil Engineering Theses - Archive

Tarrant Regional Water District (TRWD) pumps untreated raw water from Richland Chambers and Cedar Creek reservoirs in East Texas to provide water to several customer cities including Arlington and Fort Worth. TRWD adds chloramines to the pipeline to combat biofilm growth, that reduces pipeline capacity and increases pumping costs, and to control zebra mussels, that clog intake structure screens and the pump wet wells. However, addition of chloramines leads to the formation of N-nitrosodimethylamine (NDMA), a potent carcinogen, by reaction of chloramines with nitrogenous organic precursors possibly present in the raw water. NDMA formation presents a challenge to TRWD because …

Fate Of Bulk Hypochlorite Solutions In Two Water Treatment Facilities, Anna Breytus

Civil Engineering Theses - Archive

Measurement of oxyhalides in various strength hypochlorite solutions has been an issue of importance in the last decade, especially in view of the current aim of Homeland Security to reduce the usage of chlorine gas. Hypochlorite solutions have a potential of introducing disinfection by-products when used for water treatment. Previous works have shown the possibility of high levels of chlorate and perchlorate in high strength hypochlorite solutions. Perchlorate is an endocrine disruptor that inhibits iodide intake by the thyroid, thus reducing the production of essential thyroid hormones. Chlorate also has several adverse effects on the blood and thyroid systems. Perchlorate …

Mechanical Behavior Of Grouted Sands, Ryan C. Ortiz

Theses and Dissertations--Civil Engineering

Grouting techniques have been in used for many years, but several new grout materials have surfaced in recent decades that have re-defined the boundaries of the limitations of grouting programs. Typically these applications are used for seepage control in earthen impoundments, but strength of these earthen impoundments should be considered where there is potential for movement in the grouted soil mass. This study investigated initial conditions that could affect grout application effectiveness. The initial conditions in question were soil grain size and in situ moisture content. Two grouts were used, ultrafine and acrylate, and variations in pure grout properties were …

Influence Of Calcium Sulfoaluminate Cement On The Pullout Performance Of Reinforcing Fibers: An Evaluation Of The Micro-Mechanical Behavior, Robert B. Jewell

Theses and Dissertations--Civil Engineering

The objective of this research was to determine the influence of calcium sulfoaluminate (CSA) cement on reinforcing fibers by evaluating the fiber pullout behavior, and bonding characteristics, of a single fiber embedded in a cementitious paste matrix. Four types of fibers commonly used in industry were evaluated: 1) Polyvinyl alcohol; 2) Polypropylene; 3) Coated Steel; and 4) Plain Steel.

Upward trends in energy costs and potential greenhouse gas regulations favor an increased use of construction materials that require lower energy and lower CO₂ emissions to fabricate, such as CSA cement, as opposed to the production of ordinary portland cement …

Deformation-Based Excavation Support System Design Method, Sekyi K. Intsiful

Theses and Dissertations--Civil Engineering

Development in urban areas around the world has steadily increased in recent years. This rapid development has not been matched by the ever decreasing open space commonly associated with urban centers. Vertical construction, thus, lends itself a very useful solution to this problem. Deep excavation is often required for urban construction. Unfortunately, the ground movements associated with deep excavation can result in damage to adjacent buildings. Thus, it is critically important to accurately predict the damage potential of nearby deep excavations and designing adequate support systems.

A new design method is proposed, as an attempt, to address the problem. The …

Prediction Of Strength And Shear Modulus Of Compacted Clays Within An Unsaturated Critical State Framework, Corrie Walton-Macaulay

Theses and Dissertations--Civil Engineering

The objective of this research study is to determine whether the soil stiffness, from which the small-strain shear modulus is determined, can be used to predict the shearing resistance of compacted clay soil, which are invariably under conditions of partial saturation. The research program developed for this objective included three major soil testing programs of matric suction, shear modulus, and strength.

A method to estimate matric suction of field compacted clay soil was presented and it is based on the quantified effect of change in initial void ratio on the soil water characteristic behaviors. With the use of a non-nuclear …

Determining Soil Erosion With Varying Corn Stover Cover Factors, Nicole K. Koeninger

Theses and Dissertations--Biosystems and Agricultural Engineering

Since the Dust Bowl, conservation agriculture has become a common practice globally. Because of the rising interest in the use of corn biomass as a feedstock for biofuel production, the effects of corn stover removal on soil erosion were explored. It was hypothesized that selective harvesting strategies would impact soil erosion differently across a variety of slopes. Soil erosion boxes were constructed, and a rainfall simulator with an intensity of 30 mm hr^-1 for 46 min was used to create runoff from slopes of 1, 5, and 10% and three cover factor treatments (no removal and two simulated corn …