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Articles 2221 - 2250 of 2904

Full-Text Articles in Engineering

Time Depedent Queuing Models Of The National Airspace, Chatabush Roongrat Jan 2010

Time Depedent Queuing Models Of The National Airspace, Chatabush Roongrat

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

Air transportation in the US system has dramatically changed in the past few decades. The National Airspace System (NAS) has increasingly become congested. A high volume of air traffic demand is one of the major challenges of the NAS. However, air traffic is very difficult to study due to many uncertainties involved. It is important that we be able to understand the relationship under uncertainties due to aviation operations, precision of navigation and control, and traffic flow efficiency. Many queuing models have been studied to better understand and quantify these relationships. In the past decade, most queuing network models assume …


Synthesis And Characterization Of Ferromagnetic Nanowires, Poching Tsai Jan 2010

Synthesis And Characterization Of Ferromagnetic Nanowires, Poching Tsai

Material Science and Engineering Theses - Archive

Ferromagnetic nanocrystals with shape anisotropy have drawn great attention in the past decades because of their unique magnetic properties and for their potential applications in ultra-high-density magnetic recording media, exchange-coupled nanocomposite magnets and related nanodevices. In this thesis, synthesis and characterixation of ferromagnetic CoNi and CoFe nanowires are reported. CoNi nanocrystals with different size, shape and composition were successfully synthesized via a catalyst chemical solution method. It was found out that the structure and morphology can be controlled by altering the NaOH concentration, and the elongation of the nanowires can be adjusted by changing surfactants ratio and catalyst amount. Unlike …


Solid-State Tunneling Spectroscopy Of Individual Quantum Dots, Ramkumar Subramanian Jan 2010

Solid-State Tunneling Spectroscopy Of Individual Quantum Dots, Ramkumar Subramanian

Material Science and Engineering Dissertations - Archive

Quantum dots are gaining importance for their potential applications in the fields of energy harvesting, bio-labeling and treatment, in opto-electronic devices and in photonic devices. For all these applications, it is imperative to know their electronic structure. Although currently several spectroscopic techniques exist to study the electronic structure of these quantum dots, they are accompanied by other effects and do not give purely the electronic structure of the individual quantum dot. The main goals of this research are to:o To study the energy level structure of `single' quantum dots.o Develop a new spectroscopic technique that allows the measurement of the …


Transmission Electron Microscopy Studies Of Lamno₃ And La₁₋Xsrxmno₃Thin Films Grown On Various Substrates, Yinsheng Fang Jan 2010

Transmission Electron Microscopy Studies Of Lamno₃ And La₁₋Xsrxmno₃Thin Films Grown On Various Substrates, Yinsheng Fang

Material Science and Engineering Theses - Archive

LaMnO₃ (LMO) and La₁₋xSrxMnO₃ (LSMO) thin films with colossal magnetoresistance have attracted considerable interest for potential applications in many technological devices, such as magnetic sensors and read-head of computer memory. In this work, polycrystalline and epitaxial LMO and LSMO thin films were deposited on various substrates including (001) Si, (001) MgO, and (001) LaAlO₃ (LAO) using RF magnetron sputtering. The microstructures of the thin films were initially studied using X-ray diffraction. Detailed microstructure information such as crystallite of the films, grain size, epitaxial quality, crystallographic structure and film/substrate interface were studied using high-resolution transmission electron microscope (HRTEM). More specifically, Effects …


Incorporation Of Vascular Endothelial Growth Factor And Pleiotrophin Into A Multiluminal Biosynthetic Nerve Implant For The Repair Of Peripheral Nerve Long Gap Defects, An Hai Nguyen Jan 2010

Incorporation Of Vascular Endothelial Growth Factor And Pleiotrophin Into A Multiluminal Biosynthetic Nerve Implant For The Repair Of Peripheral Nerve Long Gap Defects, An Hai Nguyen

Bioengineering Theses - Archive

To repair a fully transected nerve without putting undue tension on the nerve stumps, and too circumvent many of the obvious problems of using harvested nerve grafts synthetic nerve guides have been used in the clinical setting. Thus far this strategy has met with minimal success for the repair of short defects (i.e. 1 - 2.5 cm) while any defect larger than 3 cm have failed. We hypothesize that neurotorphic support, early vascularization, and contact guidance are needed to successfully regenerate a nerve across a long-gap defect. To this end we proposed a biosynthetic nerve implant (BNI) with a multiluminal …


Synthesis And Evaluation Of Bioceramics For Orthopedics And Tissue Culture Applications, Hande Demirkiran Dec 2009

Synthesis And Evaluation Of Bioceramics For Orthopedics And Tissue Culture Applications, Hande Demirkiran

Material Science and Engineering Dissertations - Archive

Hydroxyapatite is the most well known phosphate in the biologically active phosphate ceramic family by virtue of its similarity to natural bone mineral. Among all bioglass compositions Bioglass®45S5 is one of the most bioactive glasses. This study initially started by adding different amounts (1, 2.5, 5, 10, and 25 wt. %) of Bioglass®45S5 to synthetic hydroxyapatite in order to improve the bioactivity of these bioceramics.The chemistries formed by sintering and their effect on different material properties including bioactivity were identified by using various techniques, such as powder and thin film x-ray diffraction, scanning electron microscopy coupled with energy dispersive X-ray …


Tribological Performance Of Ashless Antiwear Additives Under Extreme Pressure Conditions, Bohoon Kim Dec 2009

Tribological Performance Of Ashless Antiwear Additives Under Extreme Pressure Conditions, Bohoon Kim

Material Science and Engineering Dissertations - Archive

Zinc diakyl dithiophosphate (ZDDP) has been used in engine oil for several decades as an antiwear additive. However, ZDDP is the primary source of P, S and Zn in the exhaust, which results in frequent maintenance or replacement of exhaust gas treatment systems. The use of ashless additives is more desirable because of recent environmental regulations. The main goal of this research was to develop a fundamental understanding of how ashless compounds protect the tribological surface in comparison to ZDDP. X-ray absorption near edge structure spectroscopy (XANES) has been performed on tribo and thermal films in order to investigate the …


Self Powered Sensing By Combining Novel Sensor Architectures With Energy Harvesting, Vishwas Bedekar Dec 2009

Self Powered Sensing By Combining Novel Sensor Architectures With Energy Harvesting, Vishwas Bedekar

Material Science and Engineering Dissertations - Archive

Recent advancements in the field of wireless sensor networks have resulted in increasing demand for self-powering techniques that reduces the dependence on batteries. In order to address this problem, there has been significant effort on generating small electrical power locally by harvesting energy from freely available environmental sources such as mechanical vibrations, wind, and stray magnetic field. Further, there is need for inventing new sensing techniques to reduce the overall power consumption. The road for reaching the destination of self-powered sensor networks requires cooperative progress in reduction in sensor power consumption by developing new sensing mechanisms and local generation of …


Synthesis, Characterization And Potential Applications Of Fept Nanoparticles, Vikas Nandwana Dec 2009

Synthesis, Characterization And Potential Applications Of Fept Nanoparticles, Vikas Nandwana

Material Science and Engineering Dissertations - Archive

Monodisperse FePt nanoparticles with controlled size and geometry have drawn great attention in the last decade for fundamental scientific studies and for their potential applications in advanced materials and devices such as ultra-high-density magnetic recording media, exchange-coupled nanocomposite magnets, biomedicines and nanodevices. This dissertation focuses on the synthesis and characterization of FePt nanoparticles and their use in potential applications. The FePt nanoparticles of different size (2 to 16 nm) and shape (spherical, cubic, rod) were synthesized by a chemical solution method. The size and shape of these particles were controlled by adjusting reaction parameters. The as-synthesized FePt nanoparticles have chemically …


Climate Change Impacts On Water Resources Of The Upper Blue Nile River Basin, Ethiopia, U. Kim, Jagath J. Kaluarachchi, V. U. Smakhtin Dec 2009

Climate Change Impacts On Water Resources Of The Upper Blue Nile River Basin, Ethiopia, U. Kim, Jagath J. Kaluarachchi, V. U. Smakhtin

Civil and Environmental Engineering Faculty Publications

Climate change affects water resources availability of international river basins that are vulnerable to runoff variability of upstream countries especially with increasing water demands. The upper Blue Nile River Basin is a good example because its downstream countries, Sudan and Egypt, depend solely on Nile waters for their economic development. In this study, the impacts of climate change on both hydrology and water resources operations were analyzed using the outcomes of six different general circulation models (GCMs) for the 2050s. The outcomes of these six GCMs were weighted to provide average future changes. Hydrologic sensitivity, flow statistics, a drought index, …


Entropy Considerations In Numerical Simulations Of Non-Equilibrium Rarefied Flows, Sruti Chigullapalli, A. Venkattraman, M. S. Ivanov, Alina A. Alexeenko Nov 2009

Entropy Considerations In Numerical Simulations Of Non-Equilibrium Rarefied Flows, Sruti Chigullapalli, A. Venkattraman, M. S. Ivanov, Alina A. Alexeenko

PRISM: NNSA Center for Prediction of Reliability, Integrity and Survivability of Microsystems

Non-equilibrium rarefied flows are encountered frequently in supersonic flight at high altitudes, vacuum technology and in microscale devices. Prediction of the onset of non-equilibrium is important for accurate numerical simulation of such flows. We formulate and apply the discrete version of Boltzmann’s H-theorem for analysis of non-equilibrium onset and accuracy of numerical modeling of rarefied gas flows. The numerical modeling approach is based on the deterministic solution of kinetic model equations. The numerical solution approach comprises the discrete velocity method in the velocity space and the finite volume method in the physical space with different numerical flux schemes: the first-order, …


Assessment Of Climate Change Impacts On Water Resources Of The Upper Blue Nile River Basin, Ethiopia, U. Kim, Jagath J. Kaluarachchi Sep 2009

Assessment Of Climate Change Impacts On Water Resources Of The Upper Blue Nile River Basin, Ethiopia, U. Kim, Jagath J. Kaluarachchi

Civil and Environmental Engineering Faculty Publications

Climate change affects water resources availability of international river basins that are vulnerable to runoff variability of upstream countries especially with increasing water demands. The upper Blue Nile River Basin is a good example because its downstream countries, Sudan and Egypt, depend solely on Nile waters for their economic development. In this study, the impacts of climate change on both hydrology and water resources operations were analyzed using the outcomes of six different general circulation models (GCMs) for the 2050s. The outcomes of these six GCMs were weighted to provide average future changes. Hydrologic sensitivity, flow statistics, a drought index, …


Data Collection Methodology For Dynamic Temperature Model Testing And Corroboration, Bethany T. Neilson, David King Stevens, S. C. Chapra, Christina J. Bandaragoda Jul 2009

Data Collection Methodology For Dynamic Temperature Model Testing And Corroboration, Bethany T. Neilson, David King Stevens, S. C. Chapra, Christina J. Bandaragoda

Civil and Environmental Engineering Faculty Publications

This article describes a data collection approach for determining the significance of individual heat fluxes within streamswith an emphasis on testing (i.e. identification of possible missing heat fluxes), development, calibration and corroborationof a dynamic temperature model. The basis for developing this approach was a preliminary temperature modelling effort onthe Virgin River in southwestern Utah during a low-flow period that suggested important components of the energy balancemight be missing in the o riginal standard surface-flux temperat ure model. Possible missing heat fluxes were identi fied as bedconduction, hyporheic exchange, dead zone warming and exchange and poor representation of the amount of …


Magnetically Anchored "Reduced Trocar" Laparoscopy: Evolution Of Surgical Robotics, Richard Bergs May 2009

Magnetically Anchored "Reduced Trocar" Laparoscopy: Evolution Of Surgical Robotics, Richard Bergs

Bioengineering Theses - Archive

Laparoscopic surgery has become increasingly popular over the last few years due to its benefits; lower morbidity, less perceived pain, better cosmesis results, and less hospital time. For the surgeon however, there are fundamental issues that can make a laparoscopic procedure more difficult than simple open surgery; loss of tactile feel, limited working envelope, high demand for hand-eye coordination, and one trocar-port required for each tool. A revolutionary concept of using magnetics to support tooling across the abdominal wall was conceived by Dr. Jeffrey Cadeddu and his colleagues at the University of Texas Southwestern Medical Center. Collectively referred to as …


Synthesis And Dip-Pen Nanolithographical Patterning Of Ferrite Nanoparticles, Jingwen He Jan 2009

Synthesis And Dip-Pen Nanolithographical Patterning Of Ferrite Nanoparticles, Jingwen He

Material Science and Engineering Theses - Archive

Magnetic nanoparticles are of great interest for researchers from a wide range of disciplines, including magnetic fluids, catalysis, biotechnology/biomedicine, magnetic resonance imaging, data storage, and environmental remediation. Ferrites, a class of ferrimagnetic ceramic compounds with the chemical formula of MFe₂O₄, where M represents any one of several metallic elements such as Mg, Fe, Co, Ni, Cu and so on, are commonly used magnetic materials for nanoparticles. Magnetite (Fe3O₄) is the prototype of ferrites. Magnetite nanoparticles have been prepared through the co-precipitation of Fe²⁺ and Fe³⁺ aqueous salt solutions by addition of base. They exhibit a size distribution from 4 nm …


Synthesis And Tribological Properties Of Dlc Film By Rf Pacvd: Effect Of Processing Parameters, Pruthul Desai Jan 2009

Synthesis And Tribological Properties Of Dlc Film By Rf Pacvd: Effect Of Processing Parameters, Pruthul Desai

Material Science and Engineering Theses - Archive

Diamond-like carbon (DLC) films, have gained grounds in many industries ranging from automobile and oil and gas to electronics and bio fields due to their low friction and wear rate, chemical inertness and high hardness. Radio Frequency (RF) plasma discharge has been widely used to produce amorphous carbon films, because this method can be applied not only for etching but also for deposition on insulators. The advantage of RF plasma discharge is the application for wide area and the stability as compared with direct current (DC) plasma. The properties of DLC films deposited by RF plasma-assisted chemical vapor deposition (PACVD) …


Pool Boiling Heat Transfer Characteristics Of Nanofluids And Nanocoatings, Sang Muk Kwark Jan 2009

Pool Boiling Heat Transfer Characteristics Of Nanofluids And Nanocoatings, Sang Muk Kwark

Mechanical and Aerospace Engineering Dissertations - Archive

This research is a qualitative and quantitative investigation to understand the behaviors of nanofluids and nanocoated surfaces during pool boiling heat transfer. The pool boiling behavior of low concentration nanofluids, a mixture created by dispersing nanoparticles in pure water, was experimentally studied over a flat heater. A majority of this work was conducted using Al₂O₃ nanoparticles dispersed in water and some minor work was performed with others (CuO and diamond nanoparticles). Results from this study are consistent with those previously reported in demonstrating that boiling of nanofluids produces a nanocoating on the heater surface, and which in turn increases the …


Tribological Behavior Of Nanocrystalline Metals Prepared By Surface Mechanical Attrition Treatment, Michael Frink Jan 2009

Tribological Behavior Of Nanocrystalline Metals Prepared By Surface Mechanical Attrition Treatment, Michael Frink

Material Science and Engineering Theses - Archive

Nanocrystalline materials have shown great promise for a number of engineering applications ranging from structural and electronics to biomaterials and drug delivery. Nanoscale grain structures can cause tremendous improvements in strength, hardness and other mechanical properties. This is partially due to the suppression of dislocations within nanocrystalline grains and the entirely different deformation modes active at that scale. In spite of anticipated benefits, very little work has been performed to explore nanoscale effects on the tribological behavior of materials. Surface Mechanical Attrition Treatment (SMAT) is an effective and economical method to produce nanostructured surface layers in bulk materials. The process …


Thioacetamide As A Sulfur Precursor For Chalcopyrite Thin Film Solar Cells, Alex Alphonse Jan 2009

Thioacetamide As A Sulfur Precursor For Chalcopyrite Thin Film Solar Cells, Alex Alphonse

Material Science and Engineering Theses - Archive

Chalcopyrite CuInS₂ (CIS) thin films have the potential to be used in low cost terrestrial photovoltaic applications. The band gap of CIS is around 1.5 eV [1] and it well matches with the solar spectrum. However, the power conversion efficiencies in CIS solar cells are presently limited to 13.2% [2]. CIS absorber layers can be produced in a simple two-stage process consisting of the physical vapor deposition of a Cu-In bilayer - generally with Cu-rich composition - and its subsequent sulfurization under sulfur atmosphere made by either sulfur vapor or H₂S. While sulfur vapor is a safer option than H₂S …


Effect Of Reflow Variables On The Nanoscale Mechanical Properties Of Lead Free Solders, Tonye Adeogba Jan 2009

Effect Of Reflow Variables On The Nanoscale Mechanical Properties Of Lead Free Solders, Tonye Adeogba

Material Science and Engineering Theses - Archive

This study presents findings on the nano-mechanical properties of binary and ternary (Cu, Ag) - Sn Solders. Nanoindentation with a cube corner tip was used on Sn-Ag and SAC405 alloy compositions to investigate the effect of reflow process variables on the properties of hardness and reduced modulus on a nanoscale. The specimens tested were sandwich solder joints where Cu was the substrate. While the reflow variables of cooling rate and reflow time were found to cause changes in IMC morphology and solder matrix microstructure, the nano hardness and reduced modulus were independent of these variables. Low max loads coupled with …


Negative Differential Resistance In Hydrated Deoxyribonucleic Acid Thin Films Mediated By Diffusion-Limited Redox Reaction, Hou Kuan Lee Jan 2009

Negative Differential Resistance In Hydrated Deoxyribonucleic Acid Thin Films Mediated By Diffusion-Limited Redox Reaction, Hou Kuan Lee

Material Science and Engineering Theses - Archive

The charge transport mechanisms in DNA proposed in the literature cover broad range of possibilities including molecular band conduction, superexchange, multistep hole hopping, and polaron hopping. The reason for the surprisingly diverse results is all the variables in the experiments - DNA sequence, DNA characteristic (single molecule or bundle, DNA length), the metal/DNA contacts, and the environmental dissimilarities in temperature, humidity, etc. In this study, the humidity effect on the electrical conduction in DNA was systematically investigated in a humidity chamber over the wide range of DC voltage. The exponential increase in conduction with increasing humidity was observed for the …


Cae Tools For Modeling Inertia And Aerodynamic Properties Of An R/C Airplane, Kartik Kiran Parikh Jan 2009

Cae Tools For Modeling Inertia And Aerodynamic Properties Of An R/C Airplane, Kartik Kiran Parikh

Mechanical and Aerospace Engineering Theses - Archive

Recently there has been significant research in the field of Unmanned Aerial Vehicles (UAV). For efficient deployment and operation of these vehicles, it is imperative that one understands the physical system. This in turn involves one to design efficient control algorithms for implementation in these platforms. Thus we need algorithms and methods that identify the physical system parameters, that in turn can be used to design robust model based control systems. This thesis employs CAE software such as SolidWorks, GAMBIT and FLUENT to calculate the aerodynamic coefficients and moment of inertia. The aerodynamic coefficients are analyzed to understand the sensitivity …


Mechanism Of Wear Protection Of Al-Alloys Using Xanes, Beibei Wang Jan 2009

Mechanism Of Wear Protection Of Al-Alloys Using Xanes, Beibei Wang

Material Science and Engineering Theses - Archive

The mechanism of wear protection of Al-Si alloys in wear tests using lubricants containing Zinc dialkyl-dithiophosphate (ZDDP), Dialkyl dithiophosphate (DDP) , Amine phosphates, Thiadiazole, Antimony 0, 0-dialkylphosphorodithioate (SbDDP) was studied. Using techniques such as XANES this study examined the tribological behavior of these compounds and the characteristics of the tribofilms formed by them. High frequency reciprocating rig (HFRB) tests were conducted with lubricant containing these five antiwear additives were compared in both base oil and fully formulated oil. The tribofilms formed were then analyzed by a variety of techniques such as Scanning electron microscopy of the film and the composition …


Analysis Of Data Center Cooling Strategies And The Impact Of The Dynamic Thermal Management On The Data Center Efficiency, Veerendra Prakash Mulay Jan 2009

Analysis Of Data Center Cooling Strategies And The Impact Of The Dynamic Thermal Management On The Data Center Efficiency, Veerendra Prakash Mulay

Mechanical and Aerospace Engineering Dissertations - Archive

The power trend for Server systems continues to grow thereby making thermal management of Data centers a very challenging task. Although various configurations exist, the raised floor plenum with Computer Room Air Conditioners (CRACs) providing cold air is a popular operating strategy. The air cooling of data center however, may not address the situation where more energy is expended in cooling infrastructure than the thermal load of data center. Revised power trend projections by ASHRAE TC 9.9 predict heat load as high as 5000W per square feet of compute servers' equipment footprint by year 2010. These trend charts also indicate …


Development Of A Quantum Dot Mediated Thermometry For Minimally Invasive Thermal Therapy, Willard L. Hanson Jan 2009

Development Of A Quantum Dot Mediated Thermometry For Minimally Invasive Thermal Therapy, Willard L. Hanson

Mechanical and Aerospace Engineering Dissertations - Archive

Thermally-related, minimally invasive therapies are designed to treat tumors while minimizing damage to the surrounding tissues. Adjacent tissues become susceptible to thermal injury to ensure the cancer is completely destroyed. Destroying tumor cells, while minimizing collateral damage to the surrounding tissue, requires the capacity to control and monitor tissue temperatures both spatially and temporally. Current devices measure the tumor's tissue temperature at a specific location leaving the majority unmonitored. A point-wise application can not substantiate complete tumor destruction. This type of surgery would be more effective if volumetric tissue temperature measurement were available. On this premise, the feasibility of a …


Synergistic And Antagonistic Effect Of Sulfur-Based Additives On The Performance Of Greases With Zddp And Ptfe, Arunya Suresh Jan 2009

Synergistic And Antagonistic Effect Of Sulfur-Based Additives On The Performance Of Greases With Zddp And Ptfe, Arunya Suresh

Material Science and Engineering Theses - Archive

Lithium-base greases constitute about 50% of the grease market. The current trend is towards developing greases with longer working life and wider application flexibility. To address this concern, greases are blended with antiwear and extreme pressure (EP) additives that serve to reduce wear and increase the operating life of the machinery by creating a low strength, shearable film on the moving surfaces. In the current study, greases were developed to address the need for both performance as prescribed by the ASTM standards D2266 and D2596, respectively. The actual bearing conditions vary significantly with load, rpm and duration of test. These …


Fabrication Of Plga Nanocomposite Using Two Photon Polymerization, Nikhil Narendra Kavadia Jan 2009

Fabrication Of Plga Nanocomposite Using Two Photon Polymerization, Nikhil Narendra Kavadia

Mechanical and Aerospace Engineering Theses - Archive

The demand of smaller size 3D structures in scale of several nanometers has significantly increased the need of development of new techniques for micro/nano fabrication. Applications of nanomaterial embedded true 3D micro/nano structures in the field of medicine, tissue engineering, scaffolding, drug delivery, antibacterial implants or catheters, modification of textiles and refinement of polymers has opened new areas of research for fabrication of nanocomposites embedded with engineering nanoparticles.A novel fabrication process called two photon polymerization (2PP) is employed for the fabrication of polymeric nanocomposites embedded with PLGA nanoparticles. An ultra short pulsed laser source is used to produce laser at …


Dymore Finite Element Analysis Of The Paired Blade Tiltrotor Conceptual Design And A Comparable Conventional Tiltrotor Design, David Orion Braziel Jan 2009

Dymore Finite Element Analysis Of The Paired Blade Tiltrotor Conceptual Design And A Comparable Conventional Tiltrotor Design, David Orion Braziel

Mechanical and Aerospace Engineering Theses - Archive

Increasing the solidity of tiltrotors above that of current designs presents challenges associated with control system packaging and control couplings. The paired blade rotor concept addresses these issues by placing two blades that share a pitch link, located for acceptable control coupling, on each of three hub arms.Dymore finite element models of the paired blade rotor and a reference rotor of equal solidity with six evenly spaced blades were developed to identify any potential design flaws of the paired blade rotor associated with rotor frequency placement or control couplings. The finite element rotor models are documented, and the results of …


Numerical Simulation Of Particle Adhesion Dynamics For Applications In Nanomedicine And Biosensing, Samar Shah Jan 2009

Numerical Simulation Of Particle Adhesion Dynamics For Applications In Nanomedicine And Biosensing, Samar Shah

Mechanical and Aerospace Engineering Theses - Archive

Multifunctional nanoparticles hold considerable promise as the next generation of medicine that allow for detection of early on-set of diseases and targeted therapy with minimal toxicity. To achieve targeted drug delivery, nanoparticles are usually functionalized with certain ligands (polymers) that bind specifically to a particular type of receptors on the endothelial cell surface, which are expressed exclusively during its diseased state. The ligand coated nanoparticles, loaded with drugs inside, transport in blood stream, and adhere to diseased cells via specific adhesion. However, this whole procedure becomes complicated due to simultaneous involvement of hydrodynamic force, adhesion force and Brownian force. In …


Dynamic Stress From Transverse Impact On Flexural Beams, Joshua Ballard Jan 2009

Dynamic Stress From Transverse Impact On Flexural Beams, Joshua Ballard

Mechanical and Aerospace Engineering Theses - Archive

Accurate prediction of stress from impact would be very useful to an engineer in the design and analysis phases of a project. Currently one must resort to finite element analysis and experimentation, both of which have their negatives. Classical hand analysis methods such as the work-energy method overestimate the stress for a weight dropped onto the tip of a cantilevered beam. The goal of this project was to formulate analytical equations that were straightforward and easy to implement that would more accurately predict the dynamic stress in this scenario. Using the already derived equations from the work-energy method, a modification …