Engineering Commons^™

Dehalococcoides Abundance And Alternate Electron Acceptor Effects On Large, Flow-Through Trichloroethene Dechlorinating Columns, Babur S. Mirza, Darwin L. Sorensen, Ryan Dupont, Joan E. Mclean

Civil and Environmental Engineering Faculty Publications

Trichloroethene (TCE) in groundwater is a major health concern and biostimulation/bioaugmentation-based strategies have been evaluated to achieve complete reductive dechlorination with varying success. Different carbon sources were hypothesized to stimulate different extents of TCE reductive dechlorination. Ecological conditions that developed different dechlorination stages were investigated by quantitating Dehalococcoides 16S rRNA (Dhc) and reductive dehalogenase gene abundance, and by describing biogeochemical properties of laboratory columns in response to this biostimulation. Eight large columns (183 cm × 15.2 cm), packed with aquifer material from Hill AFB, Utah, that were continuously fed TCE for 7.5 years. Duplicate columns were biostimulated with whey or …

Continuum-Scale Investigation Of Evaporation From Bare Soil Under Different Boundary And Initial Conditions: An Evaluation Of Nonequilibrium Phase Change, Andrew C. Trautz, Kathleen M. Smits, Abdullah Cihan

Civil Engineering Faculty Publications - Archive

Evaporation and condensation in bare soils govern water and energy fluxes between the land and atmosphere. Phase change between liquid water and water vapor is commonly evaluated in soil hydrology using an assumption of instantaneous phase change (i.e., chemical equilibrium). Past experimental studies have shown that finite volatilization and condensation times can be observed under certain environmental conditions, thereby questioning the validity of this assumption. A comparison between equilibrium and nonequilibrium phase change modeling approaches showed that the latter is able to provide better estimates of evaporation, justifying the need for more research on this topic. Several formulations based on …

Quantification And Normalization Of Noise Variance With Sparsity Regularization To Enhance Diffuse Optical Tomography, Jixing Yao, Fenghua Tian, Yothin Rakvongthai, Soontorn Oraintara, Hanli Liu

Bioengineering Faculty Publications - Archive

Conventional reconstruction of diffuse optical tomography (DOT) is based on the Tikhonov regularization and the white Gaussian noise assumption. Consequently, the reconstructed DOT images usually have a low spatial resolution. In this work, we have derived a novel quantification method for noise variance based on the linear Rytov approximation of the photon diffusion equation. Specifically, we have implemented this quantification of noise variance to normalize the measurement signals from all source-detector channels along with sparsity regularization to provide high-quality DOT images. Multiple experiments from computer simulations and laboratory phantoms were performed to validate and support the newly developed algorithm. The …

Multiregional Functional Near-Infrared Spectroscopy Reveals Globally Symmetrical And Frequency-Specific Patterns Of Superficial Interference, Yujin Zhang, Fulun Tan, Xu Xu, Lian Duan, Hanli Liu, Fenghua Tian, Chao-Zhe Zhu

Bioengineering Faculty Publications - Archive

Linear regression with short source-detector separation channels (S-channels) as references is an efficient way to overcome significant physiological interference from the superficial layer for functional nearinfrared spectroscopy (fNIRS). However, the co-located configuration of Schannels and long source-detector separation channels (L-channels) is difficult to achieve in practice. In this study, we recorded superficial interference with S-channels in multiple scalp regions. We found that superficial interference has overall frequency-specific and globally symmetrical patterns. The performance of linear regression is also dependent on these patterns, indicating the possibility of simplifying the Schannel configurations for multiregional fNIRS imaging.

Dynamic Functional Connectivity Revealed By Resting-State Functional Near-Infrared Spectroscopy, Zhen Li, Hanli Liu, Jingping Xu, Wenli Liu, Fenghua Tian, Yong He, Haijing Niu, Xuhong Liao

Bioengineering Faculty Publications - Archive

No abstract provided.

Development Of A Decision-Making Methodology To Design A Water Quality Monitoring Network, J. Keum, Jagath J. Kaluarachchi

Civil and Environmental Engineering Faculty Publications

The number of water quality monitoring stations in the USA has decreased over the past few decades. Scarcity of observations can easily produce prediction uncertainty due to unreliable model calibration. An effective water quality monitoring network is important not only for model calibration and water quality prediction but also for resources management. Redundant or improperly located monitoring stations may cause increased monitoring costs without improvement to the understanding of water quality in watersheds. In this work, a decision-making methodology is proposed to design a water quality monitoring network by providing an adequate number of monitoring stations and their approximate locations …

Exploring The Effects Of Atmospheric Forcings On Evaporation: Experimental Integration Of The Atmospheric Boundary Layer And Shallow Subsurface, Kathleen Smits, Victoria Eagen, Andrew Trautz

Civil Engineering Faculty Publications - Archive

Evaporation is directly influenced by the interactions between the atmosphere, land surface and soil subsurface. This work aims to experimentally study evaporation under various surface boundary conditions to improve our current understanding and characterization of this multiphase phenomenon as well as to validate numerical heat and mass transfer theories that couple Navier-Stokes flow in the atmosphere and Darcian flow in the porous media. Experimental data were collected using a unique soil tank apparatus interfaced with a small climate controlled wind tunnel. The experimental apparatus was instrumented with a suite of state of the art sensor technologies for the continuous and …

Slaps Music Sharing App, Maximillian L. Parelius

Computer Engineering

Slaps is a fun way to share new songs with friends. Users can simply select songs from their personal library of music, select a short sample of the song to share, and then select which friends to share it with. If a user loves a song that he/she receives, they can link directly to iTunes through the app to download the full song.

Panorama: Multi-Path Ssl Authentication Using Peer Network Perspectives, William P. Harris

Computer Engineering

SSL currently uses certificates signed by Certificate Authorities (CAs) to authenticate connections. e.g. Google will pay a CA to sign a certificate for them, so that they can prove that they're not someone pretending to be Google. Unfortunately, this system has had multiple problems, and many believe that an alternative needs to be found.

One of the ideas for alternatives is using multiple "network perspectives" to authenticate a server. The idea behind this is that, though playing man-in-the-middle (MITM) with one connection is easy, it should be difficult for an adversary to do so with many connections, especially if they …

Biostimulation And Bioaugmentation To Enhance Reductive Dechlorination Of Tce In A Long-Term Flow Through Column Study, Joan E. Mclean, Jared Ervin, Jing Zhou, Darwin L. Sorensen, Ryan Dupont

Civil and Environmental Engineering Faculty Publications

Large laboratory columns (15.2 cm diameter, 183 cm long) were fed with groundwater containing trichloroethylene (TCE), were biostimulated and bioaugmented, and were monitored for over 7.5 years. The objective of the study was to observe how the selection of the carbon and energy source, i.e., whey, Newman Zone® standard surfactant emulsified oil and Newman Zone nonionic surfactant emulsified oil, affected the rate and extent of dechlorination. Column effluent was monitored for TCE and its degradation products, redox indicators (nitrate-N, Fe(II), sulfate), and changes in iron mineralogy. Total bacteria and Dehalococcoides mccartyi strains were quantified using q-PCR. Complete dechlorination was only …

Efficient Method To Cool The Data Center Using Solar Energy, Krishna Ketanbhai Desai

Mechanical and Aerospace Engineering Theses - Archive

Solar energy is the only source which is abundantly available and which can be used to power a cooling system that is based on absorption cycle. Solar cooling system can be used to provide refrigeration for food and medicines and comfort cooling also. Such systems are speci cally applicable to the large applications having large cooling loads for particularly big periods of a year. Peak demand for the cooling of a building and the highest availability of solar radiation are in similar phase, which makes solar cooling of any building a potential energy source and also a green solution. In …

Multiphase Flow Modeling And Analysis Of Filling Process For Pulsed Detonation Engines, Swati Chandran Thirumangalath

Mechanical and Aerospace Engineering Theses - Archive

The filling process of a pulsed detonation engine with fuel and oxidizer should be carried out quickly in order to maintain a high frequency of operation. The objectives of this research were to model an efficient inlet system for filling the detonation tube with fuel/air mixture in stoichiometric ratio and to evaluate various filling schemes. Numerical modeling of the filling process was done using PointwiseTM for meshing and FluentTM as the flow solver, solving the Reynolds-averaged Navier-Stokes equations with a k-? turbulence model. Five different filling configurations were studied, including endwall, normal and angled, opposing and staggered sidewall. The fuel …

Managing The Economic Constraints Of Foundries And Fabless Enterprises, Charles M. Weber, Jiting Yang

Engineering and Technology Management Faculty Publications and Presentations

This paper presents an empirically grounded model, which links organizational learning to pattern-specific fixed costs. The approach described in this paper helps fab managers make fundamental strategic decisions concerning product design and product mix by engaging in scenario planning. Four critical aspects of managing pattern-specific fixed cost are analyzed in detail – sensitivity to time, design cost and production volume; platform designs; process postponement solutions; and design penalties. The model suggests that fabless enterprises and foundries must collaborate extensively on the design and realizations of product platforms for state-of-the-art integrated circuit products to remain economically viable.

Evaluate The Impact Of Sustainability And Pipeline Quality On Global Crude Oil Supply Chain, Sunny Paraskumar Jain

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

United states is one of the largest crude oil producer in the world but the consumption rate is higher than production hence united states imports oil from varies part of world depend on different criteria. The objective of this dissertation is to evaluate the impact of pipeline quality and facility sustainability on crude oil supply chain cost for Russia and Colombia that gave idea about when and where we have to invest to satisfy United states oil requirement. In order to meet this objective, three specific criteria are investigated as follow:1. Evaluate the supply chain factors that determine pipeline quality …

Particulate-Matter Emission Estimates From Agricultural Spring-Tillage Operations Using Lidar And Inverse Modeling, Kori D. Moore, Michael D. Wojcik, Randy S. Martin, Christian C. Marchant, D. S. Jones, W. J. Bradford, G. E. Bingham, R L. Pfeiffer, J. H. Prueger, J. L. Hatfield

Civil and Environmental Engineering Faculty Publications

Particulate-matter (PM) emissions from a typical spring agricultural tillage sequence and a strip–till conservation tillage sequence in California’s San Joaquin Valley were estimated to calculate the emissions control efficiency (ηη) of the strip–till conservation management practice (CMP). Filter-based PM samplers, PM-calibrated optical particle counters (OPCs), and a PM-calibrated light detection and ranging (LIDAR) system were used to monitored upwind and downwind PM concentrations during May and June 2008. Emission rates were estimated through inverse modeling coupled with the filter and OPC measurements and through applying a mass balance to the PM concentrations derived from LIDAR data. Sampling irregularities and errors …

Experimental Validation Data For Cfd Of Transient Convection From Forced To Natural With Flow Reversal On A Vertical Flat Plate, Blake W. Lance, Barton L. Smith

Engineering Datasets

Transient convection was investigated experimentally for the purpose of providing Computational Fluid Dynamics (CFD) validation data. A specialized facility for validation experiments called the Rotatable Buoyancy Tunnel was used to acquire thermal and velocity measurements of flow over a smooth, vertical heated plate. The initial condition was forced convection downward with subsequent transition to mixed convection, ending with natural convection upward after a flow reversal. Data acquisition through the transient was repeated for ensemble-averaged results. With simple flow geometry, validation data were acquired at the benchmark level. All boundary conditions (BCs) were measured and their uncertainties quantified. Temperature profiles on …

Experimental Validation Data For Cfd Of Steady And Transient Mixed Convection On A Vertical Flat Plate, Blake W. Lance

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Simulations are becoming increasingly popular in science and engineering. One type of simulation is Computation Fluid Dynamics (CFD) that is used when closed forms solutions are impractical. The field of Verification & Validation emerged from the need to assess simulation accuracy as they often contain approximations and calibrations.

Validation involves the comparison of experimental data with simulation outputs and is the focus of this work. Errors in simulation predictions may be assessed in this way. Validation requires highly-detailed data and description to accompany these data, and uncertainties are very important.

The purpose of this work is to provide highly complete …

Du02, Center For Orthopaedic Biomechanics, Michael D. Harris, Phd, Kevin Shelburne, Phd

Natural Knee Data

No abstract provided.

Enhanced Mechanical Stability Of Interlayer Dielectrics With Self-Organized Molecular Pores, Akanksha Pandey

Material Science and Engineering Theses - Archive

In order to reduce resistance-capacitance delays in interconnect structures, ultralow-k films are used as interlayer dielectric materials. In most cases the preferred method to achieve the lower dielectric constant is the use of porous carbon doped silicon oxide (p-SiCOH) dielectrics. A downside of porosity in a dielectric layer during device fabrication is that it reduces the mechanical reliability of the dielectric and increases the susceptibility to adsorption of damaging materials. To overcome this and produce a material which can sustain the rigorous processes of fabrication, it is necessary to optimize the mechanical, thermal and chemical properties along with the electrical …

Enhanced Photocatalytic Performance Of Titania Nanobelts Decorated With Gold Particles Synthesized Using Stirring-Assisted Hydrothermal Method, Yi Shen

Material Science and Engineering Theses - Archive

In this thesis, anatase TiO2 nanobelts (TNBs) have been successfully obtained via an optimized stirring-assisted hydrothermal synthesis. The impact of stirring speed has been studied. Difference in morphology caused by stirring speed was observed by high resolution Field-Emission SEM (FE-SEM). Methylene Blue degradation test indicated that at certain stirring speed, i.e., 700 rpm, which was the highest, produced the best photoactivity than commercial P25 TiO2.Furthermore, Au decorated TNBs were obtained by a simple reduction reaction with Au-containing precursor. The Au-TNBs were founded to outperform in MB degradation the commercial P25 TiO2 and the pristine TNBs under both UV and visible …

Three-Dimensional Indeterminate Impacts In Legged Robotic Locomotion, Abhishek Chatterjee

Mechanical and Aerospace Engineering Theses - Archive

Legged robotic systems undergo a large number of impacts during walking or running tasks. These impacts occur over the surface of contact between the feet and the ground. If a rigid body assumption is held, these impacts can be analyzed by selecting a certain number of points on the impacting bodies. A minimum of three points are required for analyzing a surface contact on a plane. However, using a minimum number of points for analyzing surface impact would require an additional analysis for appropriately selecting these points. On the other hand, if a large number of evenly distributed impact points …

Biomechanical Analysis Of The Cornea To Improve Post Surgical Outcomes Through Finite Element Analysis, Salman Nasir Khan

Mechanical and Aerospace Engineering Dissertations - Archive

Vision deterioration is a major healthcare concern. It is estimated that one in three persons develops some form of vision reducing eye disease by the age of 65 and these numbers are expected to increase. Deterioration in visual acuity is due to ocular diseases that change the shape or clarity of the cornea. Health/shape of the cornea is extremely important as it determines the refractive power of the eye.This work studies ocular surgeries from a mechanical/structural engineering perspective. It begins by discussing laser in-situ keratomileusis (LASIK) surgery and explains the role of lasers in modifying the corneal shape to improve …

Design Of Cooling And Ventilation Of Telecommunication Shelter At High Altitude, Palak Patel

Mechanical and Aerospace Engineering Theses - Archive

Telecommunication shelters house information technology (IT), networking, power, and cooling equipment such as racks, power cabinets, batteries, fans, etc. For reliable operation of the IT and networking equipment, shelters need to satisfy or exceed minimum environmental guidelines for all equipment they contain. These guidelines typically contain specified operational temperature, maximum gaseous and particular contaminant levels. In this work, cooling and ventilation needs of a telecommunication shelter at an altitude of 9,678 feet are studied by modeling the system and simulating various operational and weather scenarios using FloVENT 10.1, a computational fluid dynamics (CFD) tool. The shelter contains two compartments: the …

Experimental And Computatonal Analysis Of The Effect Of Pcb Layer Copper Thickness And Prepreg Layer Stiffness On Solder Joint Reliability, Sanjay Mahesan Revathi

Mechanical and Aerospace Engineering Theses - Archive

The emphasis of this study is to find out how the solder joints of the BGA package are affected with change in the stack up PCB layer copper thickness and the prepeg layer stiffness. In general the effect of the PCB layer thickness is to increase the stress and strain range and to decrease the thermal fatigue life. Basically a PCB consists of different layers with different material properties (Eg: Cu, FR4 etc.).In this paper we deal with the PCB with 1-6-1 configuration (6 core layers and 1 prepeg layer on the top and bottom). A Prepeg is a fiber …

Study Of Hotspot Cooling For Integrated Circuits Using Electrowetting On Dielectric Digital Microfluidic System, Govindraj Shreyas Bindiganavale

Mechanical and Aerospace Engineering Dissertations - Archive

Thermal management in electronics is an ever-growing challenge which needs constant innovations to regulate hotspots in integrated circuits for safe operation within its Thermal Design Power (TDP) envelope. As the number of transistors increase due to advancements in photolithography to enable die shrink, portable electronics are on the rise and so is the demand for microscale cooling systems because conventional cooling components like heat sinks, heat pipes and fans are not capable of meeting design requirements for cooling solutions. In addition to the benefits enjoyed by microscale cooling systems like compact and lightweight design along with simple operation, electrowetting on …

Organic/Inorganic Guanidinium-Based Hybrid Anion Exchange Membranes For Alkaline Fuel Cells, Shambhavi Raju Sakri

Material Science and Engineering Theses - Archive

Organic-inorganic hybrid membranes are good alternatives to homogeneous ones to overcome the limitations posed by the individual constituent materials. These membranes pose promising applications in fuel cells with the combination of phenomenal functionality of organic polymers and stability of inorganic material. Introduction of inorganic materials into the polymer matrix is usually known to show an increase in mechanical properties of the membrane while, the organic part of the membrane, i.e., the polymer contributes towards the electrochemical properties. The properties of the individual materials combine to enhance the characteristic properties of the hybrid membranes. In this thesis we attempted to develop …

Accurate Three-Dimensional Characterization Of The Nonlinear Material Constitutive Properties For Laminated Composite Materials, Julia Elaine Cline

Mechanical and Aerospace Engineering Dissertations - Archive

Accurate and efficient full three-dimensional characterization of mechanical properties of composite materials, including stress-strain curves and strength characteristics, is essential for understanding complex deformation and failure mechanisms of composites and optimizing material qualification efforts. Non-contact full-field deformation measurement techniques such as digital image correlation (DIC) allowing for assessment of all surface strain components on the entire specimen surface, enable simpler experimental setups and material specimen designs for more efficient and accurate material characterization. This work presents a new method enabling simultaneous assessment of the shear stress-strain curves in all three principal material planes. The method uses a small rectangular plate …

Characterization Of Fracture Toughness In Amorphous Diamond Like Carbon Thin Films And Coatings, Ronaksinh Parmar

Material Science and Engineering Theses - Archive

Any material containing a crack when subjected to a certain amount of load, will eventually fail. This failure of material can be either time consuming (ductile) or instant (brittle) depending on the type of material and amount of load applied. For one to be able to study fracture toughness, it is important to study the material's failure rate and how long it can withstand load without failure once a crack has been initiated. Ductile materials demonstrate high fracture toughness while brittle materials show lower fracture toughness and fail instantly once a crack has been initiated. Characterization of fracture toughness in …

Structural Integrity Of Tsvs In 3d Package Under Thermal Loading, Parinda Patel

Mechanical and Aerospace Engineering Theses - Archive

In this advanced technological era, all electronic equipments tend to be light in weight, and have high performance with low power consumption and low prices. Gain in both performance and cost via Moore's law is starting becoming difficult post 28nm technology node. Three dimensional chips staking with TSV technology has gained momentum to meet such requirements of significant miniaturization and power reduction which result in increased performance. Vertically interconnected TSVs provide the shorter effective electrical interconnect path, resulting in reduced signal latency between strata and greater signal bandwidth. Moreover, TSVs offer high density integration, increased number of input/output terminals and …

Considerations For Generating Accurate Linear Transfer Functions For Laminar Flow Transmission Line Dynamics, Sina Jasteh

Mechanical and Aerospace Engineering Theses - Archive

Modeling fluid lines for applications such as hydraulic fracturing has been studied for many years, and we know that the inverse frequency method presents very accurate solutions for systems with lines in almost all laminar flow cases. However, utilizing this method is not easy for all users, and requires experience and understanding of the method. In this study a simplified method is introduced for accurately modeling the transients in lines which requires minimum experience in utilizing inverse frequency methods; the accuracy and limits of this simplified method are studied. Also, alternative approaches are presented which improved the accuracy of the …