Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 101821 - 101850 of 198086

Full-Text Articles in Engineering

Targeted Products From Fast-Hydropyrolysis And Hydrodeoxygenation Of Biomass, Ian Tad Smith Dec 2015

Targeted Products From Fast-Hydropyrolysis And Hydrodeoxygenation Of Biomass, Ian Tad Smith

Open Access Theses

Previously, the H2Bioil process was proposed as a possible way to convert sustainably available intact biomass into liquid fuels. The optimization of this process and possible synergies with other biomass conversion processes are presented in this thesis.

The selectivity of the PtMo hydrodeoxygenation catalyst was tuned using two different hydrogen partial pressures: 25 bar, and 2.5 bar. This effect was studied on cellulose and intact biomass samples to determine the effect that hydrogen has upon the retention of aromatic compounds found in intact biomass. These experiments show that it is possible for the hydrogenation activity of the PtMo catalyst to …


Design Of Elastic Metamaterials, Yu-Chi Su Dec 2015

Design Of Elastic Metamaterials, Yu-Chi Su

Open Access Dissertations

This study focused on the design and fabrication of a double negativity and three broadband single negativity elastic metamaterials using a 3D printer. We investigated dispersion curves and dynamic material properties of the metamaterials. Negative phase velocity in the double negativity metamaterial was also demonstrated.

For metamaterials with single negativity, three types of broadband metamaterials were designed from parametric studies. A comparison showed that using frame bending/stretching mode is more effective than applying beam bending mode to broaden bandgap. Furthermore, it is found that adding internal resonant components could enlarge the bandgap. The single negativity metamaterials were validated by numerical …


Generalized Techniques For Using System Execution Traces To Support Software Performance Analysis, Thelge Manjula Peiris Dec 2015

Generalized Techniques For Using System Execution Traces To Support Software Performance Analysis, Thelge Manjula Peiris

Open Access Dissertations

This dissertation proposes generalized techniques to support software performance analysis using system execution traces in the absence of software development artifacts such as source code. The proposed techniques do not require modifications to the source code, or to the software binaries, for the purpose of software analysis (non-intrusive). The proposed techniques are also not tightly coupled to the architecture specific details of the system being analyzed. This dissertation extends the current techniques of using system execution traces to evaluate software performance properties, such as response times, service times. The dissertation also proposes a novel technique to auto-construct a dataflow model …


Method Assessment For Microalgae Quantification In Wastewater Treatment And Biofuel Production, Kristen S. Harrison Dec 2015

Method Assessment For Microalgae Quantification In Wastewater Treatment And Biofuel Production, Kristen S. Harrison

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

There is growing interest in the use of microalgae for wastewater treatment and biofuel production. However, there is not yet a reliable, user-friendly method of quantifying the biomass and lipid production of a large sample of algae. This study aims to establish and validate new methods for green microalgae quantification using the Microplate reader and the Coulter Counter. Chlorella vulgaris was chosen as the ‘ideal’ algal species for wastewater treatment and biofuel production due to its structure, lipid production, and pollution removal ability. Three traditional quantification methods -- microscope cell count, lipid separation, and chlorophyll extraction -- were compared to …


Effect On Mechanical Properties Of Aluminium Alloy Composites On Adding Ash As Reinforcement Material, Mohd Zafaruddin Khan, Mohd Anas, Ather Hussain, Md Irshadul Haque, Kamran Rasheed Dec 2015

Effect On Mechanical Properties Of Aluminium Alloy Composites On Adding Ash As Reinforcement Material, Mohd Zafaruddin Khan, Mohd Anas, Ather Hussain, Md Irshadul Haque, Kamran Rasheed

Journal of Metals, Materials and Minerals

To produce Al-matrix cast particle composites, wettability of the ceramic particles by liquid Al is essential. To improve wettability of the solution, few elements such as Mg and Si are added into Al melt to incorporate the ceramic particles. The present investigation has been focussed on the utilization of abundant available industrial waste such as fly ash and bagasse ash in useful manner by dispersing it into Eutectic Al-Si alloy LM6 Containing 10.58% Si to produce composites by liquid casting route. The mechanical properties such as Brinell Hardness and Ultimate tensile strength has been investigated. The test results of the …


Effect Of Temperature Dropping During Solution Treatment In Rejuvenation Heat Treatment On Final Microstructures Of Udimet 520, Kritsayanee Saelor, Panyawat Wangyao Dec 2015

Effect Of Temperature Dropping During Solution Treatment In Rejuvenation Heat Treatment On Final Microstructures Of Udimet 520, Kritsayanee Saelor, Panyawat Wangyao

Journal of Metals, Materials and Minerals

Udimet 520 is a low precipitation hardened nickel-based superalloy, which is made to be turbine blades at high temperature. After long-term service, the microstructure of the turbine blades could be degraded, then the mechanical properties are worse than the new ones. The rejuvenation heat treatment of degraded turbine blades, which are made of cast Udimet 520, is following by solution treatment at 1,121C / 4 hours and then double aging processes, which include primary aging at 843 C / 24 hours and secondary aging at 760 C / 16 hours, respectively.However, in practical reheat treatment processes, the temperature during solution …


Effect Of Tig Welding Parameters On Strain-Age Cracking In Joining Nickel-Based Superalloy, Gtd-111 With Inconel 625, Athittaya Athiroj, Panyawat Wangyao Dec 2015

Effect Of Tig Welding Parameters On Strain-Age Cracking In Joining Nickel-Based Superalloy, Gtd-111 With Inconel 625, Athittaya Athiroj, Panyawat Wangyao

Journal of Metals, Materials and Minerals

Excellent mechanical properties at high temperature of nickel-based superalloys brought them to extensive application in severe operating conditions. However, the great mechanical properties deteriorate after long-term exposure to high temperature and it frequently causes failure of the component e.g. cracking. TIG welding is considered as an economical way to refurbish the minor damage component as replacement with new one is costly due to high material cost and complexity in manufacturing processes. Unfortunately, heat from welding that applies to the component may create new cracks during and after process from liquation and strain-age cracking. This phenomena is problem especially in precipitation-hardened …


Processing Of Nano Fillers In Nitrile Rubber A Novel Technique, Abitha V. K., Ajay Vasudeo Rane, K. Rajkumar Dec 2015

Processing Of Nano Fillers In Nitrile Rubber A Novel Technique, Abitha V. K., Ajay Vasudeo Rane, K. Rajkumar

Journal of Metals, Materials and Minerals

Dispersion of various nano fillers like Nano silica, nano clay, Nano TiO2, etc has been attempted in NBR rubbers using new technique of dispersion. Liquid NBR is taken as dispersion media for nano fillers in polymer matrix and polymer nano composites were characterized by Rubber Process Analyzer [RPA-2000, USA]. The dispersion of the nano fillers were investigated by XRD, SEM-EDS. The effect of increasing nano- fillers on mechanical properties like tensile strength, modulus and Elongation at break was studied. Hot air ageing of polymer nano composites was also studied.Dispersion of various nano fillers like Nano silica, nano clay, Nano TiO2, …


Microstructure Based Finite Element Simulation Of Jco Forming Process For Pipeline X65, Wut Thianngoen, Saranya Kingklang, Vitoon Uthaisangsuk Dec 2015

Microstructure Based Finite Element Simulation Of Jco Forming Process For Pipeline X65, Wut Thianngoen, Saranya Kingklang, Vitoon Uthaisangsuk

Journal of Metals, Materials and Minerals

In recent years, strong increases in energy demand have become the most important issue in every section. High strength pipeline steels make large contribution to cost reduction for fuel transportation in oil and gas industries due to their great combination of optimal strength and toughness properties. Mechanical properties of pipeline steel tubes are significantly influenced by their microstructure characteristics, which in turn are controlled by the production. In this work, the JCO forming process of gas pipeline tube made of hotrolled steel grade X65 with ferrite/pearlite microstructure was investigated by means of a FE multiscale modeling approach. Three different scales …


Petrology And Geochemistry Of The Harlan, Kellioka, And Darby Coals From The Louellen 7.5-Minute Quadrangle, Harlan County, Kentucky, Michelle N. Johnston, James C. Hower, Shifeng Dai, Peipei Wang, Panpan Xie, Jingjing Liu Dec 2015

Petrology And Geochemistry Of The Harlan, Kellioka, And Darby Coals From The Louellen 7.5-Minute Quadrangle, Harlan County, Kentucky, Michelle N. Johnston, James C. Hower, Shifeng Dai, Peipei Wang, Panpan Xie, Jingjing Liu

Center for Applied Energy Research Faculty and Staff Publications

The Harlan, Kellioka, and Darby coals in Harlan County, Kentucky, have been among the highest quality coals mined in the Central Appalachians. The Middle Pennsylvanian coals are correlative with the Upper Elkhorn No. 1 to Upper Elkhorn No. 3½ coals to the northwest of the Pine Mountain thrust fault. Much of the mining traditionally was controlled by captive, steel-company-owned mines and the coal was part of the high volatile A bituminous portion of the coking coal blend. Overall, the coals are generally low-ash and low-sulfur, contributing to their desirability as metallurgical coals. We did observe variation both in geochemistry, such …


Studying The Optimum Design Of Automotive Thermoelectric Air Conditioning, Alaa Attar Dec 2015

Studying The Optimum Design Of Automotive Thermoelectric Air Conditioning, Alaa Attar

Dissertations

The remarkable amount of research being conducted on thermoelectrics gives the impression that this technology will have a bright future in power generation and temperature control systems. At the present time, thermoelectrics is applied widely for temperature control, but has not yet replaced conventional air-conditioning systems due to its lower performance. Currently, approximately 10% of annual vehicle fuel consumption corresponds to the air-conditioning system used to cool the vehicle cabin. Conventional air-conditioning systems cool the entire cabin; however, about 73% of a vehicle’s mileage occurs while the driver is the only occupant. These facts indicate the need for a single …


Sustainability Assessment For Energy Systems And Chemical Process Industries, Michael J. Matzen Dec 2015

Sustainability Assessment For Energy Systems And Chemical Process Industries, Michael J. Matzen

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Sustainability has become an important factor in the chemical process and energy industries with a strong drive for process improvements towards more environmentally conscious solutions. However, there are many ways of defining sustainability and even more ways of trying to determine how sustainable a process is. This work looks into applying a conjunction of tools including; process simulation, multi-criteria decision matrices and life-cycle assessment to more quantitatively determine sustainability metrics. We have applied these tools for the production of electricity, methanol and dimethyl ether. A novel method of electricity production, in chemical looping combustion (CLC), was used that inherently involves …


Experimental Investigation And Thermal Modeling On Electro Discharge Drilling Of Pcd, Farnaz Nourbakhsh Dec 2015

Experimental Investigation And Thermal Modeling On Electro Discharge Drilling Of Pcd, Farnaz Nourbakhsh

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

This study presents an experimental investigation and finite element simulation of Electro Discharge Drilling (ED-Drilling) of Polycrystalline Diamond (PCD). PCD has many outstanding properties including uniformly high hardness, high wear resistance and strong corrosion which are the main causes of widely using PCD. While PCD has many advantages and an important role in industrial applications, its high level of hardness and wear resistance cause this material to be difficult to form and machine by using traditional machining methods. EDM as a nontraditional machining process is an effective method among other non-traditional methods for PCDs due to its low cost and …


Bandwidth Estimation For Virtual Networks, Ertong Zhang Dec 2015

Bandwidth Estimation For Virtual Networks, Ertong Zhang

School of Computing: Dissertations, Theses, and Student Research

Cloud computing is transforming a large part of IT industry, as evidenced by the increasing popularity of public cloud computingservices, such as Amazon Web Service, Google Cloud Platform, Microsoft Windows Azure, and Rackspace Public Cloud. Manycloud computing applications are bandwidth-intensive, and thus the network bandwidth information of clouds is important for theirusers to manage and troubleshoot the application performance.

The current bandwidth estimation methods originally developed for the traditional Internet, however, face great challenges in clouds dueto virtualization that is the main enabling technique of cloud computing. First, virtual machine scheduling, which is an importantcomponent of computer virtualization for processor …


Methodology For Selecting The Column Configuration With Lowest Media Replacement Cost For Small Adsorption Systems, Artem Bausk Dec 2015

Methodology For Selecting The Column Configuration With Lowest Media Replacement Cost For Small Adsorption Systems, Artem Bausk

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

The relative performance of three column configurations often used for adsorption systems serving small communities was evaluated in terms of which results in the lowest overall replacement cost. Replacement cost is the cost of fresh media and the transportation, labor, and material costs to replace the media. Both the adsorption capacity and the media replacement costs were modeled. The pore and surface diffusion model was utilized to simulate the fixed-bed adsorption and obtain the breakthrough curves, which were then normalized using the target effluent to influent concentration ratio (C/Co) and the mass transfer zone fraction (%MTZBT). …


Effects Of Sediments On Bmps For Highway Runoff Control, Matthew Garder Dec 2015

Effects Of Sediments On Bmps For Highway Runoff Control, Matthew Garder

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

Numerous studies conducted on highway stormwater runoff and its control with Best Management Practices (BMPs) indicate that sediment is the major pollutant that affects performance and longevity of BMPs. Currently, there are several knowledge gaps related to the effects of sediments on highway BMPs: a) how much sediment will be generated by a construction site by a section of highway with its surrounding watershed under different conditions; b) how sediment is intercepted by different BMPs with or without pretreatment sections; and c) what are the effects of these sediments on BMPs’ hydraulic behavior, longevity, and pollutants removal or release. The …


Solar Powered Picnic Table For Charging Cellphones And Other Small Devices, Casey B. Potts Dec 2015

Solar Powered Picnic Table For Charging Cellphones And Other Small Devices, Casey B. Potts

Electronic Theses and Dissertations

Solar panels are used in many different applications for generating sustainable energy. Many countries use solar power as a power generation method. It is also, an excellent option for getting power to difficult areas. There are three main systems used when generating solar power: grid-tied, battery banked, and direct driven systems. Most systems use a combination of grid-tied and battery banked so any unused power can be fed back into the main grid for compensation. The solar power application suggested in this thesis will provide USB power to a picnic table enabling students to charge cellphones and other small devices …


Condition Assessment Of Clemson University's Parking Network And Development Of A Framework To Support Pavement Management, Yazurved Sai Vishwaksen Aravalli Dec 2015

Condition Assessment Of Clemson University's Parking Network And Development Of A Framework To Support Pavement Management, Yazurved Sai Vishwaksen Aravalli

All Theses

The concept of pavement management system for Clemson University parking network provides a rehabilitation programming strategy for parking and transportation services department at Clemson University. The department invests funds to keep parking lots in good condition which pays large rewards in terms of savings for both Clemson University and parking lot users. Clemson University Pavement Management System (CU-PMS) will provide quality information for better decisions to ensure the funds invested gets the best value. This project consists of developing a useful and efficient network-level PMS for Clemson University parking lot network. The study area includes all the parking lots in …


Analysis Of Citrate Content In Bone Using High Performance Liquid Chromatography, Matthew Konstantin Pysh Dec 2015

Analysis Of Citrate Content In Bone Using High Performance Liquid Chromatography, Matthew Konstantin Pysh

All Theses

Approximately 1.5 wt. % of bone is comprised of citrate molecules bound to the surface of apatite crystals. Furthermore, 80 to 90% of physiological citrate is contained within bone. Recently, interest in citrate has increased due to the potential of a citrate based method for estimation of postmortem intervals, time since death, of skeletal remains. The broad objective of this research was to develop and validate a High-Performance Liquid Chromatography (HPLC) method for quantitative and qualitative analysis of citrate in bone. An appropriate HPLC column and operating conditions for the detection of citrate were selected and subsequently used to analyze …


Design Of A Meta-Material With Targeted Nonlinear Deformation Response, Zachary Satterfield Dec 2015

Design Of A Meta-Material With Targeted Nonlinear Deformation Response, Zachary Satterfield

All Theses

The M1 Abrams tank contains track pads consist of a high density rubber. This rubber fails prematurely due to heat buildup caused by the hysteretic nature of elastomers. It is therefore desired to replace this elastomer by a meta-material that has equivalent nonlinear deformation characteristics without this primary failure mode. A meta-material is an artificial material in the form of a periodic structure that exhibits behavior that differs from its constitutive material. After a thorough literature review, topology optimization was found as the only method used to design meta-materials. Further investigation determined topology optimization as an infeasible method to design …


Co-Design Of Dynamic Real-Time Scheduling And Cooperative Control For Human-Agent Collaboration Systems Based On Mutual Trust, Xiaotian Wang Dec 2015

Co-Design Of Dynamic Real-Time Scheduling And Cooperative Control For Human-Agent Collaboration Systems Based On Mutual Trust, Xiaotian Wang

All Theses

Mutual trust is a key factor in human-human collaboration. Inspired by this social interaction, we analyze human-agent mutual trust in the collaboration of one human and (semi)autonomous multi-agent systems. In the thesis, we derive time-series human-agent mutual trust models based on results from human factors engineering. To avoid both over- trust and under-trust, we set up dynamic timing models for the multi-agent scheduling problem and develop necessary and sufficient conditions to test the schedulability of the human multi-agent collaborative task. Furthermore, we extend the collaboration between one human and multiple agents into the collaboration between multi-human network and swarm-based agents …


Experimental Investigation Of Heat Leakage And Air Leakage In Domestic Refrigerators, Shervin Shoai Naini Dec 2015

Experimental Investigation Of Heat Leakage And Air Leakage In Domestic Refrigerators, Shervin Shoai Naini

All Theses

The optimization of the energy consumption in household refrigerators should consider the influence of the gasket which determines the heat transfer and air infiltration rate. In this research project, engineering methods are developed to evaluate the heat leakage due to the gasket and air infiltration in domestic refrigerators. In the first study, experimental and numerical approaches are applied to evaluate the gasket heat transfer based on the “Reverse Heat Load Method”. The main objective is to find the effective heat leakage with the dimensions of energy leakage per gasket length per temperature difference (W/m.K). An insulated cubic box with a …


A Robust Data Exchange Framework For Connected Vehicle Technology Supported Dynamic Transit Operations, Yucheng An Dec 2015

A Robust Data Exchange Framework For Connected Vehicle Technology Supported Dynamic Transit Operations, Yucheng An

All Theses

Transit systems are an integral part of surface transportation systems. A connected vehicle technology (CVT) supported transit system will assist the users to manage trips both dynamically and efficiently. The primary focus of this research is to develop and evaluate the performance of a secure, scalable, and resilient data exchange framework. In the developed data exchange framework, a new data analytics layer, named Transit Cloud, is used to receive data from different sources, and send it to different users for a Dynamic Transit Operations (DTO) application. The DTO application allows the transit users to request trip information and obtain itineraries, …


The Performance Of Quaternary Amplitude Modulation With Quaternary Spreading In The Presence Of Interfering Signals, Allison Manhard Dec 2015

The Performance Of Quaternary Amplitude Modulation With Quaternary Spreading In The Presence Of Interfering Signals, Allison Manhard

All Theses

Multiple-access digital communications is considered with direct-sequence spread-spectrum (DS-SS) quadrature amplitude modulation and quaternary spreading in each transmission. Each transmitted signal undergoes attenuation and a delay at a receiver in the additive white Gaussian noise channel. The receiver uses coherent demodulation with a correlation detector synchronized to the one of the K received signals so that the K - 1 other transmissions act as interference. The average probability of error at the output of the detector is determined using Monte Carlo simulation and compared with an approximation in which the interference component in each detection statistic is approximated by a …


Decellularized Bovine Nucleus Pulposus As A Biomimetic Scaffold For Intervertebral Disc Regeneration, Christopher Fernandez Dec 2015

Decellularized Bovine Nucleus Pulposus As A Biomimetic Scaffold For Intervertebral Disc Regeneration, Christopher Fernandez

All Theses

Low back pain (LBP) is a significant burden with a lifetime prevalence of 84% and estimated expenditures of $85.9 billion.[1,2] Although LBP is multifactorial; it has been shown that LBP can originate from degenerating intervertebral discs (IVDs); a process which initiates in the nucleus pulposus (NP); a hydrated tissue primarily composed of type 2 collagen and proteoglycan. Current therapies for IVD degeneration (IDD) are palliative and merely delay surgical management. While these procedures may relieve pain temporarily, they fail to address the underlying cause of degeneration and make no attempt to regenerate the effected tissue. Additional concerns with the use …


Control Of Thermoforming Process Parameters To Manufacture Surfaces With Pin-Based Tooling, Vijay Sarthy Mysore Sreedhara Dec 2015

Control Of Thermoforming Process Parameters To Manufacture Surfaces With Pin-Based Tooling, Vijay Sarthy Mysore Sreedhara

All Theses

Many manufacturing processes used to mass produce parts rely on expensive and time consuming tooling. These processes include sheet metal forming, injection molding, casting, and thermoforming. The time invested in design and development of tooling can be justified for high-production volumes. However, for low-volume production and customized products, the tooling investment cannot be amortized. Flexible tooling has been developed to address the needs of smaller production volumes. Reconfigurable pin tooling is an example of flexible tooling that relies on a matrix of adjustable-height pins to produce approximate surfaces. A key challenge in pin-based tooling is achieving accurate high quality surfaces …


Electrical Characterization Of Gold And Platinum Thin Film Electrodes With Polyaniline Modified Surfaces, John Aggas Dec 2015

Electrical Characterization Of Gold And Platinum Thin Film Electrodes With Polyaniline Modified Surfaces, John Aggas

All Theses

Recent studies into soft organic electronics have burgeoned as a result of discoveries of conducting polymers such as polyaniline, polythiophene, and polypyrrole. However, in order to make these conducting polymers suitable for in vivo soft organic electronics, they must be developed so that they can be biocompatible and provide accurate sensing. Chitosan, a naturally occurring polymer structure found in exoskeletons of crustaceans, has been studied for its biocompatible properties. Composites of polyaniline (PAn), an intrinsically conductive polymer (ICP) and chitosan (Chi), a biopolymer, were developed and applied to gold and platinum Thin Film Electrode (TFE) devices. Electropolymerization and drop cast …


An Examination Of Microbial Community Composition At Tba-Degrading Versus Non-Degrading Sites, Courtney Thompson Dec 2015

An Examination Of Microbial Community Composition At Tba-Degrading Versus Non-Degrading Sites, Courtney Thompson

All Theses

Understanding how fuel oxygenates interact with microorganisms in the subsurface is important for the remediation of contaminated sites and designing and optimizing remedial strategies. The current understanding of methyl tertiary butyl ether (MTBE) and tertiary butyl alcohol (TBA) degradation in the environment has been developed primarily through gas chromatography GC analysis and culture-based laboratory studies. Microbial communities can be very diverse, and while microcosm studies provide valuable data, few metagenomic studies have been performed. To elucidate the significant microorganisms and pathways involved in the breakdown of MTBE and TBA, the compositions of entire indigenous microbial populations must be investigated and …


Structural Optimization Using Parametric Programming Method, Krupakaran Ravichandraan Dec 2015

Structural Optimization Using Parametric Programming Method, Krupakaran Ravichandraan

All Theses

The Parametric Programming method is investigated to consider its applicability to structural optimization problems. It is used to solve optimization problems that have design variables as implicit functions of some independent input parameter(s). It provides optimal solutions as a parametric function of the input parameter(s) for the entire parameter space of interest. It does not require the detailed discrete optimizations needed at a large number of parameter values as in traditional non-parametric optimization. Parametric programming is widely used in optimal controls, model predictive control, scheduling, process synthesis and material design under uncertainty due to the above mentioned benefits. Its benefits …


Single Particle And Biological Cell Detection By A Radio Frequency Interferometer, Zheng Wang Dec 2015

Single Particle And Biological Cell Detection By A Radio Frequency Interferometer, Zheng Wang

All Theses

This thesis presents a series of studies on single particle and biological cell detection and differentiation by a radio frequency (RF) interferometer system. Several techniques, such as dielectrophoresis (DEP), time domain method and 3D focusing have been illustrated and investigated to demonstrate the capacity of interrogating the electric property of single particle or biological cell by the RF interferometer. Silica particles and live yeast cells are trapped at the sensing area by DEP force and detected by the RF sensor. Solutions of particle mixtures (~4 μm silica and ~10 μm polystyrene) and cell mixtures (viable and non-viable yeast cells, normal …