Engineering Commons^™

Geographic Variation In Potential Of Residential Solar Hot Water System Performance In The United States, Florida Solar Energy Center, Camilo Gil

FSEC Energy Research Center®

This paper describes an assessment of residential solar water heater performance around the continental United States. We performed annual simulations using an hourly simulation model (EGUSA) for 212 TMY3 weather locations around the nation. The annual simulations show how standard hot water energy use for electric and gas systems vary geographically (kWh and therms) as well as the potential energy savings from solar water heaters. A key finding is that the energy necessary for water heating varies by 2:1 around the U.S. with implications for solar water heating system design and sizing. Our results provide information on expected water heater …

Colloidal Electroluminescence: Novel Routes To Controlled Emission Of Organic Light Emitting Diode Devices, Christopher Huebner

All Dissertations

In recent years the importance of the organic light emitting diode (OLED) has grown immensely, and the past two decades have seen ongoing and exhaustive research in organic routes to solid state lighting,
wherein electricity is directly converted into emitted light through an excited state relaxation mechanism. The benefits of incorporating polymeric and small molecule materials into solid state lighting devices include high efficiences, low production costs, amenability to large-scale production and devices, reduced environmental impact and low energy consumption. Herein are presented novel routes to materials engineering and preparation, device fabrication and emission tailoring through the abilility to form …

Stable And Reproducible Electronic Conduction Through Dna Molecular Junctions, Ajit K. Mahapatro, Gil Lee, Kyung J. Jeong, David B. Janes

Birck and NCN Publications

This letter presents the observation of stable and reproducible electronic conduction through double stranded (ds) DNA molecules in a nominally dry state. Stable conduction was realized by immobilizing 15 base-pair guanine:cytosine rich dsDNA within gold nanogap junctions, stabilizing the dsDNA with a polycation, and characterizing in nitrogen. In air, the current levels decrease with successive voltage scans likely due to oxidation of the guanine bases under bias. In nitrogen, reproducible current-voltage traces are observed and the current levels at specific bias points are stable with time. The stability allows comprehensive electrical studies and could enable conductance-based DNA sensors.

Strain Relaxation In Si/Ge/Si Nanoscale Bars From Molecular Dynamics Simulations, Yumi Park, Hasan Metin Atkulga, Ananth Y. Grama, Alejandro Strachan

Birck and NCN Publications

We use molecular dynamics (MD) with the reactive interatomic potential ReaxFF to characterize the local strains of epitaxial Si/Ge/Si nanoscale bars as a function of their width and height. While the longitudinal strain (along the bars length) is independent of geometry, surface relaxation leads to transverse strain relaxation in the Ge section. This strain relaxation increases with increasing height of the Ge section and reduction in its width and is complete (i.e., zero transverse strain) for roughly square cross sections of Ge leading to a uniaxial strain state. Such strain state is desirable in some microelectronics applications. From the MD …

Strain Relaxation In Si/Ge/Si Nanoscale Bars From Molecular Dynamics Simulations, Yumi Park, Hasan Atkulga, Ananth Y. Grama, Alejandro Strachan

Birck and NCN Publications

We use molecular dynamics (MD) with the reactive interatomic potential ReaxFF to characterize the local strains of epitaxial Si/Ge/Si nanoscale bars as a function of their width and height. While the longitudinal strain (along the bars length) is independent of geometry, surface relaxation leads to transverse strain relaxation in the Ge section. This strain relaxation increases with increasing height of the Ge section and reduction in its width and is complete (i.e., zero transverse strain) for roughly square cross sections of Ge leading to a uniaxial strain state. Such strain state is desirable in some microelectronics applications. From the MD …

Self-Supporting Nanowire Arrays Templated In Sacrificial Branched Porous Anodic Alumina For Thermoelectric Devices, Kalapi G. Biswas, Hatem El Matbouly, Vijay Rawat, Jeremy L. Schroeder, Timothy D. Sands

Birck and NCN Publications

Templated synthesis of thermoelectric nanowires in porous anodic alumina (PAA) have potential for enhanced performance relative to bulk materials. A significant challenge is the template material, which can serve as a thermal shunt. In this work, an approach for creating a branched PAA template is described. The process utilizes localized self-heating to destabilize the planar anodization front, yielding branched and interconnected pores growing at a rate of 300 mu m/h. The template is selectively etched after electrodeposition of desired materials, yielding self-supporting nanowire arrays with thicknesses up to about 300 mu m, thereby eliminating the thermal shunt through the template.

Thermionic Emission Energy Distribution From Nanocrystalline Diamond Films For Direct Thermal-Electrical Energy Conversion Applications, Kishore Uppireddi, Tyler Westover, Timothy Fisher, Brad Weiner, Gerardo Morell

Birck and NCN Publications

In the ongoing quest for energy production by nonconventional methods, energy conversion by vacuum and solid-state thermionic emission devices is one of the potentially efficient pathways for converting thermal energy directly into electrical power. The realization of practical of thermionic energy conversion devices strongly depends on achieving low work function materials, which is thus far a limiting factor. In an attempt to develop a new low work function thermionic material, this work reports thermionic emission energy distributions (TEEDs) from nanocrystalline diamond (NCD) films in the temperature range from 700 to 900 °C that reveal a consistent effective work function of …

Synthesis And Characterization Of Some Rhenium Complexes, Joseph Brian Scott

Masters Theses & Specialist Projects

Plastics or polymers are thought to behave oppositely from metals. Ideally, polymers behave as insulators while metals conduct electricity. Shirakawa and coworkers discovered conductive polymers in 1977.1 These conductor polymers have been extensively studied, discovering that charge transfer oxidative doping of polyacteylene could increase its conductivity by 12 orders of magnitude. Polyacetylene, although showing promise as an organic conductor, because it is highly air-sensitive and oxidizes when exposed to molecular oxygen, therefore making this an unattractive use for commercial products. Attention has been focused on heterocylic aromatic polymers such as polythiophene and polypyrrole, in efforts to produce conductive polymers that …

Lignin And Lipid Impact On Sorption And Diffusion Of Trichloroethylene In Tree Branches For Determining Contaminant Fate During Plant Sampling And Phytoremediation, Gayathri Gopalakrishnan, Joel Gerard Burken, Charles J. Werth

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Plants Draw All They Need from their Surrounding Environment and in Doing So Also Draw Anthropogenic Contaminants from their Surroundings. Several Natural Processes (E.g., Active Transport, Diffusion, Sorption, and Degradation) Occur within Trees and Affect Chemical Concentrations in Tree Samples. This Study Elucidates Tree Contaminant Chemical Interactions on Equilibrium Sorption and Diffusion into Branch Tissue (I.e., Wood Core and Bark), Specifically the Impacts of Lipid and Lignin Content. Five Tree Species Were Selected to Span a Range of Lignin and Lipid Contents. Linear Isotherms Were Obtained for All Sampled Species over a Limited Concentration Range (2 Μg/ ML < C Gas < 12 Μg/mL), and Equilibrium Distribution Coefficients (Kd) Were Linearly Correlated to Lipid (R2 > 0.83) But …

Effects Of Meeting Spaces On The Performance Of A Concept Selection Task By Engineering Design Teams, Necmettin Ozkan

All Theses

Given the increasing importance of collaboration and the resulting use of virtual tools, this research investigates the performance of engineering design teams using a concept selection task in three meeting spaces, face-to-face, 2D online and 3D virtual. Cisco's WebEx and Sun Microsystems' Wonderland were used as the 2D online meeting space and the 3D virtual environment, respectively. Twenty-four two-person design teams were formed and randomly assigned to the meeting spaces. Eight teams performed a cell-phone concept selection task in each meeting space. Four dependent variables were measured: task completion time, team satisfaction, self-evaluated quality and expert-evaluated quality. Following data collection, …

The Effect Of Bio-Based Materials On Quality And Shelf Life Of Celery, Chike Ifezue

All Theses

Bio-based materials have garnered increasing interest as food packaging
materials because they are derived from renewable resources such
as corn starch, cellulose and sugar beet. These materials do have the disadvantage
of having
poor mechanical performance compared to non-bio based materials and their
effect on quality and shelf life of some produce is unknown.
This research studied the effect of three bio-based materials on quality
and self life of celery. Materials consist of biopolymer films and LDPE
film. The variable materials were: Polylactic Acid (PLA), a versatile
biodegradable aliphatic polyester derived from 100% renewable resources,
Ecoflex, a biodegradable aliphatic-aromatic copolyester, …

High Efficient Electrical Stimulation Of Hippocampal Slices With Vertically Aligned Carbon Nanofiber Microbrush Array, Edward D. De Asis Jr., T. D. Barbara Nguyen-Vu, Prabhu U. Arumugam, Hua Chen, Alan M. Cassell, Russell J. Andrews, Cary Y. Yang, Jun Li

Electrical and Computer Engineering

Long-term neuroprostheses for functional electrical stimulation must efficiently stimulate tissue without electrolyzing water and raising the extracellular pH to toxic levels. Comparison of the stimulation efficiency of tungsten wire electrodes (W wires), platinum microelectrode arrays (PtMEA), as-grown vertically aligned carbon nanofiber microbrush arrays (VACNF MBAs), and polypyrrole coated (PPy-coated) VACNF MBAs in eliciting field potentials in the hippocampus slice indicates that, at low stimulating voltages that preclude the electrolysis of water, only the PPy-coated VACNF MBA is able to stimulate the CA₃ to CA₁ pathway. Unlike the W wires, PtMEA, as-grown VACNF MBA, and the PPy-coated VACNF MBA …

Estimation Of Maximum Achievable End-To-End Throughput In Ieee 802.11 Based Wireless Mesh Networks, Gayatri Venkatesh

All Theses

Wireless mesh networks can be quickly deployed in various situations to provide temporary to permanent wireless network coverage. To assess the feasibility and reliability of a given end-to-end communication need, it is essential for communication end points to accurately estimate their achievable end-to-end throughput. Several capacity, end-to-end throughput, and available bandwidth estimation techniques have been studied in the past for wired and wireless networks. The contention among wireless nodes arising due to the IEEE 802.11 medium access control protocol's channel access mechanism renders the estimation of such network attributes challenging in multi-hop networks. This thesis evaluates Adhoc Probe, one state-of-the-art …

Characterization And Enhancement Of Sensing Properties Of Piezoelectric Materials With Applications To Vibration Suppression, Siddharth Aphale

All Theses

This thesis undertakes the study of piezoelectric properties of polymer-based fabric and film sensors. An enhancement in piezoelectric properties of such sensors, as noted through earlier work, is observed with increasing weight ratios of nanomaterials dispersed in the polymer matrix. A comprehensive mathematical model using cantilever beams is developed to analyze this enhancement both qualitatively and quantitatively. An experimental setup is also developed to implement the proposed real time signal processing necessary to collect required data towards the characterization. In order to distinguish piezoelectric materials from other materials, study of the frequency response of developed fabric sensors to periodic chirp …

Design Of Acousto-Optic Chaos Based Secure Free-Space Optical Communication Links, Anjan K. Ghosh, Pramode K. Verma, Samuel Cheng, Robert C. Huck, Monish Ranjan Chatterjee, Mohammed A. Al-Saedi

Electrical and Computer Engineering Faculty Publications

We discuss the design of an acousto-optic cell based free space optical communication link where the data beam is made secure through chaos encryption. Using external signal modulation of the diffracted light from a hybrid acousto-optic cell chaos (or directly via incorporation in the sound-cell driver's bias voltage) encryption of data is possible. We have shown numerically that decryption of the encoded data is possible by using an identical acousto-optic system in the receiver.

Active Human Power Generation: As A New Portion Of The Energy Supply, Robert J. Mccleary Ii

Library Research Grants

The discovery and use of energy has revolutionized society for more then two hundred years. With it we have witnessed an explosion of knowledge and technology unparallel in history. Unfortunately our main sources of energy are in limited supply. In order to continue to enjoy the progress made during these last few centuries it is necessary to know both when our supply will run out and to find alternative sources.

The question of when the fossil fuels will run out has been on the minds of many scientists for more than fifty years. In 1956 Dr. M. King Hubbert developed …

The Very Basics Of Sustainability - An Alternative Viewpoint (Slides With Audio) (Large File! To Speed Up Download, Right-Click On "Download" Link To Save To Own Pc.), Jim Mcgovern

Other resources

This presentation sets out the very basics of ‘sustainability’, although a definition of sustainability is not attempted. Some of the very basics are the context in which the Earth and humankind exist in space and time, the Earth’s climate, the Earth’s population and humankind’s options and choices. The author advocates keeping an open mind on all available options, including the use of oil, gas, coal, tar sands, carbon capture and sequestration, nuclear power etc., as well as the technologies that are more widely considered ‘green’. The author also argues that, in addressing the challenges that humankind faces, globally concerted effort …

Morphology Of Ingaas Multilayer Nanostructure On Gaas High-Index Surfaces, Yanze Xie

Graduate Theses and Dissertations

This work aimed to explore nanostructure configuration by growing multiple layers of strained InGaAs on GaAs high index surface. The knowledge learned would help to achieve a comprehensive picture of strain-driven nanostructure evolution. Ordered arrays of InGaAs quantum dots were demonstrated on GaAs(311)B. The ordering patterns depended on the thickness of GaAs interlayer between InGaAs Quantum Dots (QDs). With an increased interfacial thickness, a transition from two dimensional (2D) lateral ordering to 1D dot chains was observed. InGaAs growth on GaAs(311)A and GaAs(331)A ended up with 1D quantum wires (QWRs). Straight InGaAs QWRs were uniformly distributed across the surfaces owing …

On The Modeling Of Energy Harvesters And Analysis Of Their Response Under Time-Varying Frequency Excitations, Thiago Seuaciuc-Osorio

All Theses

Energy harvesting is a process by which otherwise wasted ambient energy can be captured and transformed into a useful form. Historical examples of this concept include windmills, sailing ships, and waterwheels. Modern technologies and current energy needs have brought this same concept to a smaller scale wherein small wireless devices with minute energy consumption can be operated autonomously. Today, many critical electronic devices, such as health-monitoring sensors, pace makers, spinal stimulators, electric pain relievers, etc. require minimal amounts of power to function, which permits utilizing energy from their environment to power them. By exploiting the ability of active materials and …

Hierarchical Bayesian Cortical Models: Analysis And Acceleration On Multicore Architectures, Pavan Yalamanchili

All Theses

There is a significant interest in the research community to develop large scale,
high performance implementations of neuromorphic models. These have the potential to
provide significantly stronger information processing capabilities than current computing
algorithms. This thesis examines the parallelization of two recent biologically inspired
hierarchical Bayesian cortical models onto recent multicore architectures. These models
have been developed recently based on new insights from neuroscience and have several
advantages over traditional neural networks. In particular, they need far fewer network
nodes to simulate a large scale cortical model than traditional neural networks, making
them computationally more efficient. This is the first …

Chameleon Coatings: Adaptive Surfaces To Reduce Friction And Wear In Extreme Environments, Christopher Muratore, Andrey A. Voevodin

Chemical and Materials Engineering Faculty Publications

Adaptive nanocomposite coating materials that automatically and reversibly adjust their surface composition and morphology via multiple mechanisms are a promising development for the reduction of friction and wear over broad ranges of ambient conditions encountered in aerospace applications, such as cycling of temperature and atmospheric composition. Materials selection for these composites is based on extensive study of interactions occurring between solid lubricants and their surroundings, especially with novel in situ surface characterization techniques used to identify adaptive behavior on size scales ranging from 10−10 to 10−4 m. Recent insights on operative solid-lubricant mechanisms and their dependency upon the ambient environment …

Effects Of Bypasses, Jon D. Fricker, Joshua B. Mills

JTRP Technical Reports

This study aims to investigate the long-term impacts of bypasses on small- and medium-sized communities in Indiana. Interviews were conducted with community officials and individuals familiar with the history of each bypassed community. Statistical models were developed to analyze economic impacts across a number of key indicators including payroll and employment in various industry sectors. Lessons learned from this study vary from county to county and across industry sectors. The findings of this study will be used to develop a concise guide that will provide guidance to both Indiana Department of Transportation (INDOT) officials and community officials as to how …

Assessing Vaginal Surgical Skills Using Video Motion Analysis, Gouri B. Diwadkar, Antonie J. Van Den Bogert, Matthew D. Barber, J. Eric Jelovsek

Mechanical Engineering Faculty Publications

OBJECTIVE: To demonstrate the feasibility of using video motion analysis to quantitate a key step of vaginal hysterectomy and define measurable differences between novice and experienced surgical trainees during vaginal hysterectomy.

METHODS: Analyses focused on clamping, transecting, and suturing the left uterosacral ligament. Using a cutoff of 25, trainees were grouped as experienced (n=14) and novice (n=9) based on the total number of vaginal hysterectomies performed by each trainee. Contrasting-groups analysis was used to determine cutoff values that separated novices from experts.

RESULTS: Novice trainees took longer (112 seconds compared with 84 seconds) and had greater cumulative translational motion (92 …

Comparison Of Failure Mechanisms For Cements Used In Skeletal Luting Applications, O. Clarkin, D. Boyd, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glass Polyalkenoate Cements (GPCs) based on strontium calcium zinc silicate (Sr-Ca-Zn-SiO₂) glasses and low molecular weight poly (acrylic acid) (PAA) have been shown to exhibit suitable compressive strength (65 MPa) and flexural strength (14 MPa) for orthopaedic luting applications. In this study, two such GPC formulations, alongside two commercial cements (Simplex ® P and Hydroset™) were examined. Fracture toughness and tensile bond strength to sintered hydroxyapatite and a biomedical titanium alloy were examined. Fracture toughness of the commercial Poly(methyl methacrylate) cement, Simplex® P, (3.02 MPa m^1/2) was superior to that of the novel GPC (0.36 MPa …

Factors Affecting Redox Magnetohydrodynamics For Flow In Small Volumes, Matthew D. Gerner

Graduate Theses and Dissertations

Lab-on-a-chip technologies offer the possibility of developing analytical devices that are low-cost, portable, disposable, fast, and operable by non-technical personnel. Such devices require automated methods to manipulate ultra-small volumes (picoliters) of samples and solution, including pumping, stirring, and positioning. Current methods for ultra-small volume microfluidics have limitations that restrict their use including high voltage requirements, disadvantageous flow profiles or rates, and relatively complicated fabrication due to mechanical parts. Redox magnetohydrodyanmics (RMHD) that utilizes permanent magnets for portability shows promise as a micropump with ease of switching flow direction, no moving parts, compatibility with both aqueous and non-aqueous solutions, low voltages …

Motion Segmentation From Clustering Of Sparse Point Features Using Spatially Constrained Mixture Models, Shrinivas Pundlik

All Dissertations

Motion is one of the strongest cues available for segmentation. While motion segmentation finds wide ranging applications in object detection, tracking, surveillance, robotics, image and video compression, scene reconstruction, video editing, and so on, it faces various challenges such as accurate motion recovery from noisy data, varying complexity of the models required to describe the computed image motion, the dynamic nature of the scene that may include a large number of independently moving objects undergoing occlusions, and the need to make high-level decisions while dealing with long image sequences. Keeping the sparse point features as the pivotal point, this thesis …

Inferring Gene Regulatory Networks From Time Series Microarray Data, Peng Li

Dissertations

The innovations and improvements in high-throughput genomic technologies, such as DNA microarray, make it possible for biologists to simultaneously measure dependencies and regulations among genes on a genome-wide scale and provide us genetic information. An important objective of the functional genomics is to understand the controlling mechanism of the expression of these genes and encode the knowledge into gene regulatory network (GRN). To achieve this, computational and statistical algorithms are especially needed.

Inference of GRN is a very challenging task for computational biologists because the degree of freedom of the parameters is redundant. Various computational approaches have been proposed for …

National Urban Database And Access Portal Tool, Nudapt, Jason Ching, Michael Brown, Steven Burian, Fei Chen, Ron Cionco, Adel Hanna, Torrin Hultgren, Timothy Mcpherson, David J. Sailor, Haider Taha, David Williams

Mechanical and Materials Engineering Faculty Publications and Presentations

Based on the need for advanced treatments of high resolution urban morphological features (e.g., buildings, trees) in meteorological, dispersion, air quality and human exposure modeling systems for future urban applications, a new project was launched called the National Urban Database and Access Portal Tool (NUDAPT). NUDAPT is sponsored by the U.S. Environmental Protection Agency (USEPA) and involves collaborations and contributions from many groups including federal and state agencies and from private and academic institutions here and in other countries. It is designed to produce and provide gridded fields of urban canopy parameters for various new and advanced descriptions of model …

Computing For Knowledge Management: From Nonaka To Visualisation And Knowledge Maps, Helmut Huber

Dissertations

Management itself is not always clearly understood, however, the confusion can be sorted if the underlying theory is clearly distinguished from its implementations. There also may be a specific role for computing in Knowledge Management. It is suggested that Knowledge Management technologists seek a unique strategic position for Computing in Knowledge Management, for reasons of clarity and differentiation from Information Systems. The effective transfer of knowledge is one of the main themes or core competency in Knowledge Management. This is also one of the areas where Knowledge Management technologists may find the niche for a distinct and unique contribution the …

Verification Of Lrfd Bridge Design And Analysis Software For Indot, Amit H. Varma, Jungil Seo

JTRP Technical Reports

NCHRP Process 12-50 was implemented to evaluate and verify composite steel I-girder bridge design software used commonly in Indiana. A test-bed of twenty one bridges was developed with the guidance from an Indiana Department of Transportation appointed research advisory panel (RAP). The test-bed included five simple-span and sixteen multi-span bridge superstructures. More than 80 parameters were required to define a bridge and they include bridge span, girder spacing, number of beams, section type, steel strength, girder sections, and other required bridge parameters. Some of these parameters were initially selected by INDOT and practitioners.

An indigenous computer program PURDUE CSBD was …