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2012

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Articles 5731 - 5760 of 6303

Full-Text Articles in Engineering

Curcumin-Loaded Magnetic Nanoparticles For Breast Cancer Therapeutics And Imaging Applications, Murali M. Yallapu, Shadi F. Othman, Evan T. Curtis, Nichole A. Bauer, Neeraj Chauhan, Deepak Kumar, Meena Jaggi, Subhash C. Chauhan Jan 2012

Curcumin-Loaded Magnetic Nanoparticles For Breast Cancer Therapeutics And Imaging Applications, Murali M. Yallapu, Shadi F. Othman, Evan T. Curtis, Nichole A. Bauer, Neeraj Chauhan, Deepak Kumar, Meena Jaggi, Subhash C. Chauhan

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Breast cancer is a commonly diagnosed cancer among women in the United States. It is estimated that 230,480 women were diagnosed with, and 39,520 women died from, breast cancer in 2011 in the United States.1 Basal-like breast cancer accounts for 15% of all breast cancers and has a poor prognosis. The majority of these cancers are referred to as triple-negative breast cancers because they do not over express estrogen receptor, progesterone receptor, or human epidermal growth factor receptor 2.2,3 Chemotherapy is an effective option to treat such cancers; however, chemotherapy is always associated with several sets of side …


Ferroelectric Control Of Magnetocrystalline Anisotropy At Cobalt/Poly(Vinylidene Fluoride) Interfaces, Pavel Lukashev, Tula R. Paudel, Juan M. López-Encarnación, Shireen Adenwalla, Evgeny Y. Tsymbal, Julian P. Velev Jan 2012

Ferroelectric Control Of Magnetocrystalline Anisotropy At Cobalt/Poly(Vinylidene Fluoride) Interfaces, Pavel Lukashev, Tula R. Paudel, Juan M. López-Encarnación, Shireen Adenwalla, Evgeny Y. Tsymbal, Julian P. Velev

Shireen Adenwalla Papers

Electric field control of magnetization is one of the promising avenues for achieving high-density energy-efficient magnetic data storage. Ferroelectric materials can be especially useful for that purpose as a source of very large switchable electric fields when interfaced with a ferromagnet. Organic ferroelectrics, such as poly(vinylidene fluoride) (PVDF), have an additional advantage of being weakly bonded to the ferromagnet, thus minimizing undesirable effects such as interface chemical modification and/or strain coupling. In this work we use first-principles density functional calculations of Co/PVDF heterostructures to demonstrate the effect of ferroelectric polarization of PVDF on the interface magnetocrystalline anisotropy that controls the …


Head Ejection During Barrier Impacts, Scott K. Rosenbaugh, Ronald K. Faller, Dean L. Sicking Jan 2012

Head Ejection During Barrier Impacts, Scott K. Rosenbaugh, Ronald K. Faller, Dean L. Sicking

Department of Civil and Environmental Engineering: Faculty Publications

During oblique vehicular impacts with longitudinal barriers, an occupant’s head is often ejected out of a side window. When this occurs, the occupant’s head can contact the barrier or an object attached thereto. This impact event, often termed head slap, normally produces a serious injury or fatality. Roadside barriers and any attached hardware should be designed with sufficient offset at the top to preclude head slap for most impact conditions. The goal of this study was to identify the extent of head ejection that can be expected during high-speed crashes with longitudinal barriers. High-speed videos of full-scale vehicle crash tests …


Drop Weight Testing On Sandwich Panels With A Novel Thermoplastic Core Material, Christopher Y. Tuan Jan 2012

Drop Weight Testing On Sandwich Panels With A Novel Thermoplastic Core Material, Christopher Y. Tuan

Department of Civil and Environmental Engineering: Faculty Publications

A series of drop weight tests were conducted to evaluate the dynamic flatwise compression strength and flexural strength of sandwich panels with a novel core structure. This sandwich core material, known as Norcore, consists of interconnected cells in a unique configuration of truncated pyramid with sloping cell walls. Core materials made of thermoplastic including virgin Lexan, polycarbonate, polycarbonate regrind, high-impact polystyrene, and acrylonitrile butadiene styrene were tested. The test results showed that these sandwich panels have good strength as well as energy absorption capacities.


Evaluation Of Ice-Melting Capacities Of Deicing Chemicals, B. M. Gerbino-Bevins, Christopher Y. Tuan, M. Mattison Jan 2012

Evaluation Of Ice-Melting Capacities Of Deicing Chemicals, B. M. Gerbino-Bevins, Christopher Y. Tuan, M. Mattison

Department of Civil and Environmental Engineering: Faculty Publications

Common deicing chemicals include sodium chloride, magnesium chloride, calcium chloride, calcium magnesium acetate, potassium acetate, potassium formate, and corn or beet-based deicer solution. Liquid deicers are commonly used for pre-wetting road salt, sand or other solid deicers, or mixed with salt brine as liquid deicer. Although manufacturers provide performance data under specific conditions, a standardized test is very much needed. Samples of sodium chloride, magnesium chloride, calcium chloride, potassium acetate, and beet juice-based chemical deicers were selected for performance evaluation. The SHRP Ice-Melting Capacity Test has been used in many research projects, but the results do not always correlate well …


Self‐Regulating Action Exploration In Reinforcement Learning, Teck-Hou Teng, Ah-Hwee Tan, Yuan-Sin Tan Jan 2012

Self‐Regulating Action Exploration In Reinforcement Learning, Teck-Hou Teng, Ah-Hwee Tan, Yuan-Sin Tan

Research Collection School Of Computing and Information Systems

The basic tenet of a learning process is for an agent to learn for only as much and as long as it is necessary. With reinforcement learning, the learning process is divided between exploration and exploitation. Given the complexity of the problem domain and the randomness of the learning process, the exact duration of the reinforcement learning process can never be known with certainty. Using an inaccurate number of training iterations leads either to the non-convergence or the over-training of the learning agent. This work addresses such issues by proposing a technique to self-regulate the exploration rate and training duration …


A Novel Qos-Aware Mpeg-4 Video Delivery Algorithm Over The Lossy Ieee 802.11 Wlans To Improve The Video Quality, Tanmoy Debnath Jan 2012

A Novel Qos-Aware Mpeg-4 Video Delivery Algorithm Over The Lossy Ieee 802.11 Wlans To Improve The Video Quality, Tanmoy Debnath

Doctoral

Video traffic is bursty in nature and has different network requirements compared to other types of traffic (e.g. voice, data) in terms of bandwidth, delay, jitter, and loss etc. So it becomes important to manage video traffic on a WLAN carefully to achieve acceptable levels of Quality of Service (QoS). The unique contribution of this work is that it presents experimental and simulation studies of the performance of real video content streamed over WLAN networks. Under various test scenarios the performance of the WLAN network in terms of delay, loss, throughput etc. is analysed in the presence of background traffic. …


Energy Issues Affecting Corn/Soybean Systems: Challenges For Sustainable Production, Douglas L. Karlen, David Archer, Adam Liska, Seth Meyer Jan 2012

Energy Issues Affecting Corn/Soybean Systems: Challenges For Sustainable Production, Douglas L. Karlen, David Archer, Adam Liska, Seth Meyer

Adam Liska Papers

Quantifying energy issues associated with agricultural systems, even for a two-crop corn (Zea mays L.) and soybean (Glycine max [L.] Merr.) rotation, is not a simple task. It becomes even more complicated if the goal is to include all aspects of sustainability (i.e., economic, environmental, and social). This Issue Paper examines energy issues associated with and affecting corn/soybean rotations by first defining the size of the system from both a U.S. and global perspective and then establishing boundaries based on the Farm Bill definition of sustainability. This structured approach is essential to help quantify energy issues within corn/soybean …


Mononuclear Phagocyte Intercellular Crosstalk Facilitates Transmission Of Cell-Targeted Nanoformulated Antiretroviral Drugs To Human Brain Endothelial Cells, Georgette D. Kanmogne, Sangya Singh, Upal Roy, Xinming Liu, Joellyn Mcmillan, Santhi Gorantla, Shantanu Balkundi, Nathan Smith, Yazen Alnouti, Nagsen Gautam, You Zhou, Larisa Poluektova, Alexander Kabanov, Tatiana Bronich, Howard Gendelman Jan 2012

Mononuclear Phagocyte Intercellular Crosstalk Facilitates Transmission Of Cell-Targeted Nanoformulated Antiretroviral Drugs To Human Brain Endothelial Cells, Georgette D. Kanmogne, Sangya Singh, Upal Roy, Xinming Liu, Joellyn Mcmillan, Santhi Gorantla, Shantanu Balkundi, Nathan Smith, Yazen Alnouti, Nagsen Gautam, You Zhou, Larisa Poluektova, Alexander Kabanov, Tatiana Bronich, Howard Gendelman

Nebraska Center for Biotechnology: Faculty and Staff Publications

Despite the successes of antiretroviral therapy (ART), HIV-associated neurocognitive disorders remain prevalent in infected people. This is due, in part, to incomplete ART penetration across the blood–brain barrier (BBB) and lymph nodes and to the establishment of viral sanctuaries within the central nervous system. In efforts to improve ART delivery, our laboratories developed a macrophage-carriage system for nanoformulated crystalline ART (nanoART) (atazanavir, ritonavir, indinavir, and efavirenz). We demonstrate that nanoART transfer from mononuclear phagocytes (MP) to human brain microvascular endothelial cells (HBMEC) can be realized through cell-to-cell contacts, which can facilitate drug passage across the BBB. Coculturing of donor MP …


Robust Execution Strategy For Scheduling Under Uncertainity, Na Fu Jan 2012

Robust Execution Strategy For Scheduling Under Uncertainity, Na Fu

Dissertations and Theses Collection (Open Access)

Resource Constrained Project Scheduling Problems with minimum and maximum time lags (RCPSP/max) provides a general model for resource scheduling in many real-world problems (such as manufacturing and construction engineering). Due to its practical importance and generality, providing effective algorithms and scalable solutions for RCPSP/max is a topic of growing research. Traditional methods have addressed deterministic models with all parameters known with certainty. In this thesis, we are concerned with RCPSP/max problems in an uncertain environment where durations of activities are stochastic and resource availabilities are subject to unforeseen breakdowns. We propose methods for generating robust execution strategy to protect against …


Go Niche Or Go Home: Influence Maximization In The Presence Of Strong Opponent, Long Foong Liow Jan 2012

Go Niche Or Go Home: Influence Maximization In The Presence Of Strong Opponent, Long Foong Liow

Dissertations and Theses Collection (Open Access)

In hotly contested product categories dominated by a few powerful firms, it is quite common for weaker or late entrants to focus only on particular segments of the whole market. The rationale for such strategy is intuitive: to avoid direct confrontation with heavy-weight firms, and to concentrate in segments where these weaker firms have comparative advantages. In marketing, this is what people called “go niche or go home”. The niche-building strategy may rely on “homophily”, which implies that consumers in a particular market segment might possess certain set of attributes that cause them to appreciate certain products better (in other …


On Critical Infrastructure Interdependency, Polinpapilinho F. Katina, C. Ariel Pinto Jan 2012

On Critical Infrastructure Interdependency, Polinpapilinho F. Katina, C. Ariel Pinto

Engineering Management & Systems Engineering Faculty Publications

Developing effective protection, mitigation, and recovery measures for critical infrastructure (CI) systems is paramount in the wake of increasing natural and manmade hazards, risks, and threats. Influencing protection, rescue, and recovery measures are interplays (i.e., interdependencies) among infrastructure systems. Understanding interdependencies plays an essential role in minimizing and reducing cascading failures among complex interdependent infrastructure systems. This paper asserts that deployment of protection, mitigation, and recovery solutions can have little effect on infrastructure management if infrastructure operators and policymakers have partial understanding of infrastructure interdependencies. Using narrative research, authors illustrate that effective coordination and response for protection, mitigation, and recovery …


Application Of Electrospinning Technique In The Fabrication Of A Composite Electrode For Pemfc, Joshua Sightler, Eli Mcpherson, William A. Rigdon, Xinyu Huang Jan 2012

Application Of Electrospinning Technique In The Fabrication Of A Composite Electrode For Pemfc, Joshua Sightler, Eli Mcpherson, William A. Rigdon, Xinyu Huang

Faculty Publications

The Pt/C catalysts were mixed with carbon nanotube (CNT), Nafion™ dispersion and a fiber former, polymer poly-acrylic acid (PAA), to form an ink. The ink was deposited onto aluminum foil attached to a rotating collector via an electrospinning process. The ink composition, mixing procedure, and the E-spin parameters were studied for producing a uniform nanofiber mat on the aluminum substrate. The fiber-mat containing active catalyst ingredients was heat treated and decal transferred onto a Nafion membrane to form a membrane electrode assembly (MEA).


Dual Mode Sensing With Low-Profile Piezoelectric Thin Wafer Sensors For Steel Bridge Crack Detection And Diagnosis, Lingyu Yu, S. Momeni, V. Godinez, Victor Giurgiutiu, Paul Ziehl, J. Yu Jan 2012

Dual Mode Sensing With Low-Profile Piezoelectric Thin Wafer Sensors For Steel Bridge Crack Detection And Diagnosis, Lingyu Yu, S. Momeni, V. Godinez, Victor Giurgiutiu, Paul Ziehl, J. Yu

Faculty Publications

Monitoring of fatigue cracking in steel bridges is of high interest to many bridge owners and agencies. Due to the variety of deterioration sources and locations of bridge defects, there is currently no single method that can detect and address the potential sources globally. In this paper, we presented a dual mode sensing methodology integrating acoustic emission and ultrasonic wave inspection based on the use of low-profile piezoelectric wafer active sensors (PWAS). After introducing the research background and piezoelectric sensing principles, PWAS crack detection in passive acoustic emission mode is first presented. Their acoustic emission detection capability has been validated …


Magic From Human Regenerative Technologies -- Stem Cells, John M. Ritz Jan 2012

Magic From Human Regenerative Technologies -- Stem Cells, John M. Ritz

STEMPS Faculty Publications

The article discusses the developments in stem cell research and development. It mentions that through tissue engineering or regenerative medicine, many diseases are finding techniques for improvement and cure. It discusses the role of stem cells in mending the human body and the ethics associated with this technology . It is mentioned that stem cells are divided in 2 types: embryonic stem cells and adult stem cells. It includes the process of cell differentiation which determines the properties and characteristics of cells. It mentions several diseases related to sports injury, spinal cord injuries, blood and heart disorders to be to …


Green Transportation For A Green Earth, Petros J. Katsioloudis, Mildred V. Jones Jan 2012

Green Transportation For A Green Earth, Petros J. Katsioloudis, Mildred V. Jones

STEMPS Faculty Publications

Transportation is one of the biggest contributors to the destruction of the environment. Results from environmental research and pursuant governmental regulations are changing the way companies do business and how transportation systems address the future. The Environmental Protection Agency (EPA) has been at the forefront in leading environmental research and instituting policies and regulations to fight the issues impacting the environment. The transportation industry and consumers alike are concerned about the environment, energy resources, efficiencies, and economics. In this article, the authors suggest that it is vital that people promote the protection of the environment and strengthen the laws that …


Real-World Performance Of Longitudinal Barriers Struck By Large Trucks, Doug Gabauer Jan 2012

Real-World Performance Of Longitudinal Barriers Struck By Large Trucks, Doug Gabauer

Faculty Journal Articles

Outside of relatively limited crash testing with large trucks, very little is known regarding the performance of traffic barriers subjected to real-world large truck impacts. The purpose of this study was to investigate real-world large truck impacts into traffic barriers to determine barrier crash involvement rates, the impact performance of barriers not specifically designed to redirect large trucks, and the real-world performance of large-truck-specific barriers. Data sources included the Fatality Analysis Reporting System (2000-2009), the General Estimates System (2000-2009) and 155 in-depth large truck-to-barrier crashes from the Large Truck Crash Causation Study. Large truck impacts with a longitudinal barrier were …


Subsurface Phosphorus Transport And Scale Dependent Phosphorus Leaching In Alluvial Floodplains, Derek Michael Heeren Jan 2012

Subsurface Phosphorus Transport And Scale Dependent Phosphorus Leaching In Alluvial Floodplains, Derek Michael Heeren

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Increased nutrient loads have resulted in several adverse impacts on surface water quality, including excessive algal growth, fish kills, and drinking water taste and odor issues across the United States and especially in the Ozark ecoregion of northeastern Oklahoma and northwestern Arkansas. Nitrogen is a concern, but phosphorus (P) is generally considered the limiting nutrient in most surface water systems. Scientists and engineers need to identify critical nutrient source areas and transport mechanisms within a catchment in order to cost effectively protect and enhance drinking water systems, recreation activities, and aquatic ecosystems. While surface runoff is considered to be the …


Tsunami Hydrodynamics In The Columbia River, Harry Yeh, Elena Tolkova, David A. Jay, Stefan A. Talke, Hermann Fritz Jan 2012

Tsunami Hydrodynamics In The Columbia River, Harry Yeh, Elena Tolkova, David A. Jay, Stefan A. Talke, Hermann Fritz

Civil and Environmental Engineering Faculty Publications and Presentations

On 11 March 2011, the Tohoku Tsunami overtopped a weir and penetrated 49 km up the Kitakami River, the fourth largest river in Japan. Similarly, the 2010 Chile tsunami propagated at least 15 km up the Maule River. In the Pacific Northwest of the United States, large tsunamis have occurred along the Cascadia subduction zone, most recently the 'orphan tsunami' of 1700 (Atwater et al.). The expected future occurrence of a Cascadia tsunami and its penetration into the Lower Columbia River became the subject of “the Workshop on Tsunami Hydrodynamics in a Large River” held in Corvallis, Oregon, 2011. We …


Identification Of The Biogenic Compounds Responsible For Size-Dependent Nanoparticle Growth, Paul M. Winkler, John Ortega, Thomas Karl, Luca Cappellin, Hans R. Friedli, Kelley Barsanti, Peter H. Mcmurry, James N. Smith Jan 2012

Identification Of The Biogenic Compounds Responsible For Size-Dependent Nanoparticle Growth, Paul M. Winkler, John Ortega, Thomas Karl, Luca Cappellin, Hans R. Friedli, Kelley Barsanti, Peter H. Mcmurry, James N. Smith

Civil and Environmental Engineering Faculty Publications and Presentations

The probability that freshly nucleated nanoparticles can survive to become cloud condensation nuclei is highly sensitive to particle growth rates. Much of the growth of newly formed ambient nanoparticles can be attributed to oxidized organic vapors originating from biogenic precursor gases. In this study we investigated the chemical composition of size-selected biogenic nanoparticles in the size range from 10 to 40 nm. Particles were formed in a flow tube reactor by ozonolysis ofα-pinene and analyzed with a Thermal Desorption Chemical Ionization Mass Spectrometer. While we found similar composition in 10 and 20 nm particles, the relative amounts of …


Climate Change Impact Assessment For Surface Transportation In The Pacific Northwest And Alaska, John Macarthur, Philip Mote, Miguel A. Figliozzi, Jason Ideker, Ming Lee Jan 2012

Climate Change Impact Assessment For Surface Transportation In The Pacific Northwest And Alaska, John Macarthur, Philip Mote, Miguel A. Figliozzi, Jason Ideker, Ming Lee

Civil and Environmental Engineering Faculty Publications and Presentations

The states in the Pacific Northwest and Alaska region share interconnected transportation networks for people, goods, and services that support the regional economy, mobility, and human safety. Regional weather has and will continue to affect the physical condition and serviceability of these networks, yet the nature of climate changes and their potential impacts on the regional transportation system and its use are very poorly understood. The world’s leading climate scientists, such as the Intergovernmental Panel for Climate Change, have reached consensus that global climate changes are being observed and will continue into the future, particularly increasing temperatures. Given this fact, …


Multiuser Perspectives On Separated, On-Street Bicycle Infrastructure, Christopher Monsere, Nathan Mcneil, Jennifer Dill Jan 2012

Multiuser Perspectives On Separated, On-Street Bicycle Infrastructure, Christopher Monsere, Nathan Mcneil, Jennifer Dill

Civil and Environmental Engineering Faculty Publications and Presentations

In the early fall of 2009, the Bureau of Transportation in Portland, Oregon, installed a cycle track and a pair of buffered bike lanes in downtown Portland. A major objective was to test facilities that were thought to bring higher levels of comfort to bicycle riders through increased separation from motor vehicle traffic. After one year of use, an evaluation was conducted to determine how the facilities affected the experience of the various users. Intercept surveys of cyclists (n 5 248), motorists (n 5 262), pedestrians (n 5 198), and adjacent businesses (n 5 59) showed improved perceptions of safety …


Air Quality At Bus Stops: Empirical Analysis Of Exposure To Particulate Matter At Bus Stop Shelters, Miguel Figliozzi, Adam Moore, Christopher Monsere Jan 2012

Air Quality At Bus Stops: Empirical Analysis Of Exposure To Particulate Matter At Bus Stop Shelters, Miguel Figliozzi, Adam Moore, Christopher Monsere

Civil and Environmental Engineering Faculty Publications and Presentations

Congested traffic corridors in dense urban areas are key contributors to the degradation of urban air quality. While waiting at bus stops, transit patrons may be exposed to greater amounts of vehicle-based pollution, including particulate matter (PM), because of their proximity to the roadway. Current guidelines for the location and the design of bus stops do not take into account air quality or exposure considerations. This study compared the exposure of transit riders waiting at three-sided bus stop shelters that either faced the roadway traffic or faced away from the roadway traffic. Shelters were instrumented with air quality monitoring equipment, …


Energetic Nanoparticles As Fuel Additives For Enhanced Performance In Propulsion Systems, Srinibas Karmakar Jan 2012

Energetic Nanoparticles As Fuel Additives For Enhanced Performance In Propulsion Systems, Srinibas Karmakar

LSU Doctoral Dissertations

Biofuels are currently being explored as a carbon-neutral fuel alternative to petroleum-based fuels. However, biofuels such as ethanol has lower energy density (~27MJ/kg) relative to petroleum fuels (~ 45 MJ/kg). Adding high-energy density particles (such as boron with heating value of ~ 58.5 MJ/kg) to biofuels can generate fuel slurry with higher energy density than the base fuel, and represents a potential strategy toward making biofuels more viable. However, the combustion of boron is inhibited (specifically, the ignition is delayed) by the initial presence of an oxide layer, and its high evaporation and boiling temperatures. The present study investigates the …


Biological Evaluation Of A Novel Tissue Engineering Scaffold Of Layered Double Hydroxides (Ldhs), Fateme Fayyazbakhsh, Mehran Solati-Hashjin, M. A. Shokrgozar, S. Bonakdar, Y. Ganji, N. Mirjordavi, S. A. Ghavimi, P. Khashayar Jan 2012

Biological Evaluation Of A Novel Tissue Engineering Scaffold Of Layered Double Hydroxides (Ldhs), Fateme Fayyazbakhsh, Mehran Solati-Hashjin, M. A. Shokrgozar, S. Bonakdar, Y. Ganji, N. Mirjordavi, S. A. Ghavimi, P. Khashayar

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Bone Tissue Engineering (BTE) Composed of Three Main Parts: Scaffold, Cells and Signaling Factors. Several Materials and Composites Are Suggested as a Scaffold for BTE. Biocompatibility is One of the Most Important Property of a BTE Scaffold. in This Work Synthesis of a Novel Nanocomposite Including Layered Double Hydroxides (LDH) and Gelatin is Carried Out and its Biological Properties Were Studied. the Co-Precipitation (PH=11) Method Was Used to Prepare the LDH Powder, using Calcium Nitrate, Magesium Nitrate and Aluminum Nitrate Salts as Starting Materials. the Resulted Precipitates Were Dried. X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron …


Calling For Justice In The Goldfields Of Tanzania, Madoshi H. Makene, Jody Emel, James T. Murphy Jan 2012

Calling For Justice In The Goldfields Of Tanzania, Madoshi H. Makene, Jody Emel, James T. Murphy

Geography

Tanzania is the third largest gold exporter in Africa, thanks in part to the liberalization of the mining sector which started in the early 1990s. Neoliberal mining reforms promised a win-win situation in which government, investors and local host communities would benefit through export earnings, profits, local employment, andcorporate social responsibility initiatives (e.g., the building of schools and clinics). While the rising price of gold and foreign investments in mining activities have delivered on some of these promises, many residents in mining regions have not benefited socioeconomically. Worse still, their communities have unjustly borne the brunt of the environmental, social, …


Coolant Fluid In A Turning Operation: Soybean Coolant Fluid In Different Concentrations Versus Petroleum Coolant Fluid, Mary Esther Eckman Jan 2012

Coolant Fluid In A Turning Operation: Soybean Coolant Fluid In Different Concentrations Versus Petroleum Coolant Fluid, Mary Esther Eckman

Dissertations and Theses @ UNI

The manufacturing sector today's market felt the need to reduce costs along with the ability to be more "green."

Traditionally petroleum based fluids are used in the manufacturing industry. However they are environmentally more harmful as well as cause significant hazards to the operator. This thesis will provide a case study for this sector to become more environmentally friendly with the use of a soybean based cutting fluid. To prove the point a number of tests were performed turning 4140 steel on a CNC turning center. A number of tests were conducted to provide a comparative study of dry, petroleum …


Computationally Efficient Finite Element Models Of The Lumbar Spine For The Evaluation Of Spine Mechanics And Device Performance, Sean D. Smith Jan 2012

Computationally Efficient Finite Element Models Of The Lumbar Spine For The Evaluation Of Spine Mechanics And Device Performance, Sean D. Smith

Electronic Theses and Dissertations

Finite Element models of the lumbar spine are commonly used for the study of spine mechanics and device performance, but have limited usefulness in some applications such as clinical and design phase assessments due to long analysis times. In this study a computationally efficient L4-L5 FSU model and a L1-Sacrum multi-segment model were developed and validated. The FSU is a functional spine unit consisting of two adjacent vertebral bodies, in this case L4 and L5. The multi-segment model consists of all lumbar vertebrae and the sacrum. The models are able to accurately predict spine kinematics with significantly reduced analysis times, …


Explicit Finite Element Modeling Of The Human Lumbar Spine, Milind Rao Jan 2012

Explicit Finite Element Modeling Of The Human Lumbar Spine, Milind Rao

Electronic Theses and Dissertations

Validated finite element (FE) models of the functional spinal unit (FSU) and lumbar spine are essential in design-phase device development and in assessing the mechanics associated with normal spine function and degenerative disc disease (DDD), as well as the impact of fusion and total disc replacement (TDR). Although experimental data from fully intact specimens can be used for model calibration and validation, the contributions from the individual structures (disc, facets, and ligaments) may be inappropriately distributed. Hence, creation of decompression conditions or device implantations that require structure removal may not have the proper resulting mechanics. An explicit FE formulation may …


Low-Voltage Closed Loop Mems Actuators, Shahrzad Towfighian, Glenn Heppler, Eihab Abdel-Rahman Jan 2012

Low-Voltage Closed Loop Mems Actuators, Shahrzad Towfighian, Glenn Heppler, Eihab Abdel-Rahman

Mechanical Engineering Faculty Scholarship

An efficient electrostatic resonator is designed by adding a low voltage controller to an electrostatic actuator. The closedloop actuator shows stable, and bi-sable behaviors with bounded chaotic oscillations as large as 117% of the capacitor gap. The controller voltage is decreased from a previously designed resonator to less than 9 V thereby reducing the load on the controller circuit components. Bifurcation diagrams are obtained showing the frequency and magnitude of AC voltage required for chaotic oscillations to develop. The information entropy, a measure of chaotic characteristic, is calculated for the micro-resonator and is found to be 0.732.