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2009

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Articles 2791 - 2820 of 4158

Full-Text Articles in Engineering

Echo-State-Network-Based Real-Time Wind Speed Estimation For Wind Power Generation, Wei Qiao Jan 2009

Echo-State-Network-Based Real-Time Wind Speed Estimation For Wind Power Generation, Wei Qiao

Department of Electrical and Computer Engineering: Faculty Publications

Wind turbine generators (WTGs) are usually equipped with one or more well-calibrated nemometers to measure wind speed for system monitoring, control, and protection. The use of these mechanical sensors increases the cost and hardware complexity and reduces the reliability of the WTG system. This paper proposes an echo-state-network (ESN)-based real-time wind speed estimation algorithm for WTG systems. The ESN is designed to provide a nonlinear inverse model of the WTG dynamics, which is used to estimate the wind speed in real time from the measured WTG output electrical power and shaft speed at any turbine blade pitch angle. The estimated …

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Laser-Induced Resonant Excitation Of Ethylene Molecules In C2H4/C2H2/O2 Reactions To Enhance Diamond Deposition, Hao Ling, Jian Sun, X. Han, T. Gebre, Z. Q. Xie, M. Zhao, Yongfeng Lu Jan 2009

Laser-Induced Resonant Excitation Of Ethylene Molecules In C2H4/C2H2/O2 Reactions To Enhance Diamond Deposition, Hao Ling, Jian Sun, X. Han, T. Gebre, Z. Q. Xie, M. Zhao, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

Vibrational resonant excitation of ethylene (C2H4) molecules using a carbon dioxide laser was employed to promote reactions in precursors of ethylene, acetylene (C2H2), and oxygen to enhance diamond deposition. One of the vibrational modes (CH2 wag mode, v7) of the C2H4 molecules was selected to achieve the resonant excitation in the reactions. Optical emission spectroscopy was used to study the effects of laser resonant excitation on the reactions for diamond deposition. The optical emissions of CH and C2 species were enhanced with the laser excitation, …

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Rubric For Presentation Evaluation, Paul Savory Jan 2009

Rubric For Presentation Evaluation, Paul Savory

Department of Industrial and Management Systems Engineering: Instructional Materials

I have developed this rubric to allow classmates and myself to offer an evaluation or assessment of a student classroom presentation. It is my attempt to develop a standardized evaluation linked to specified criteria, making the grading process simpler and more transparent.

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Rubric For Project Report Evaluation, Paul Savory Jan 2009

Rubric For Project Report Evaluation, Paul Savory

Department of Industrial and Management Systems Engineering: Instructional Materials

I have developed this rubric to formalize the evaluation or assessment of a project report. It is my attempt to develop a standardized evaluation linked to specified criteria, making the grading process simpler and more transparent.

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Simulation Of Corn Stover And Distillers Grains Gasification With Aspen Plus, Ajay Kumar, Hossein Noureddini, Yaşar Demirel, David Jones, Milford Hanna Jan 2009

Simulation Of Corn Stover And Distillers Grains Gasification With Aspen Plus, Ajay Kumar, Hossein Noureddini, Yaşar Demirel, David Jones, Milford Hanna

Yaşar Demirel Publications

A model was developed to simulate the performance of a lab‐scale gasifier and predict the flowrate and composition of product from given biomass composition and gasifier operating conditions using Aspen Plus software. Mass balance, energy balance, and minimization of Gibbs free energy during the gasification were applied to determine the product gas composition. Carbon conversion efficiency and tar content were provided to the model as inputs as these could not be predicted by the model based on minimization of Gibbs free energy. Experiments for validation of the model were performed on a lab‐scale fluidized bed gasifier using corn stover and …

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Samplemaskinginellipsometerand The Like Systems Including Detection Of Substrate Backside Reflections, Martin M. Liphardt, James D. Welch, Corey L. Bungay, John A. Woollam Jan 2009

Samplemaskinginellipsometerand The Like Systems Including Detection Of Substrate Backside Reflections, Martin M. Liphardt, James D. Welch, Corey L. Bungay, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

A system and method of preventing substrate backside reflected components in a beam of electromagnetic radiation caused to reflect from the surface of a sample in an ellipsometer or polarimeter system, involving placing a mask adjacent to the surface of the sample which allows electromagnetic radiation to access the sample over only a limited area, wherein to access the sample over only a limited area, wherein the mask can include detector elements for collecting electromagnetic radiation reflected from the sample backside.

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The Ethical Phenomenon Of Gm-Corn: Anger, Anxiety, And Arrogance In Crossing American Borders, Jules Simon Jan 2009

The Ethical Phenomenon Of Gm-Corn: Anger, Anxiety, And Arrogance In Crossing American Borders, Jules Simon

Departmental Papers (Philosophy)

In terms of phenomenology, I often wonder about the relevance of what I do as a philosopher for the life of those with whom I come into contact. This ‘coming into contact’ happens for me on several levels: as one human among many, as a husband and father and son and brother, as a teacher, as a neighbor, and as country or city dweller. I remember with fondness those times in the late sultry summer months when, as a youth, I would drive with my father to this or that local farm-stand on some remote back road in the hills …

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Infrared Light Activated Floating Micro Stimulators For Neuro-Prosthetic Applications, Kimberlyn M. Gray Jan 2009

Infrared Light Activated Floating Micro Stimulators For Neuro-Prosthetic Applications, Kimberlyn M. Gray

Doctoral Dissertations

The most common failures in neural stimulation implants are due to interconnect complications such as tissue response, lead migration, and lead breakages. The challenge in eliminating interconnects lies in minimizing device size to maintain spatial selectivity required in the CNS. One approach to this problem is a current generating device that can be stimulated by an external signal, such as light or sound. Here, we report the design, construction and testing of rnicrophotodiode devices that can be stimulated remotely with near-infrared (NIR) light to generate current that can be injected locally into the peripheral nervous system. The use of near-infrared …

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Doe Climate Change Research Program: Strategic Plan Jan 2009

Doe Climate Change Research Program: Strategic Plan

United States Department of Energy: Publications

Advance the forefront of climate change research to provide the nation with the scientific knowledge it needs about the effects of greenhouse gas emissions on Earth's climate and biosphere to support effective energy and environmental decision making.

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Mineralogical Transformations Controlling Acid Mine Drainage Chemistry, T. Peretyazhko, John M. Zachara, J.-F. Boily, Y. Xia, P.L. Gassman, B.W. Arey, W.D. Burgos Jan 2009

Mineralogical Transformations Controlling Acid Mine Drainage Chemistry, T. Peretyazhko, John M. Zachara, J.-F. Boily, Y. Xia, P.L. Gassman, B.W. Arey, W.D. Burgos

United States Department of Energy: Publications

The role of Fe(III) minerals in controlling acid mine drainage (AMD) chemistry was studied using samples from two AMD sites [Gum Boot (GB) and Fridays-2 (FR)] located in northern Pennsylvania. Chemical extractions, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) were used to identify and characterize Fe(III) phases. The mineralogical analysis revealed schwertmannite and goethite as the principal Fe(III) phases in the sediments. Schwertmannite particles occurred as sub-micron sized spheroids. Their transformation into goethite occurred at the GB site where poorly-crystallized goethite rich in surface-bound sulfate was initially formed. In contrast, no schwertmannite transformation occurred …

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Production And Characterization Of Foam Glass From Container Glass Waste, Dina Mohamed Abdel Alim Jan 2009

Production And Characterization Of Foam Glass From Container Glass Waste, Dina Mohamed Abdel Alim

Archived Theses and Dissertations

No abstract provided.

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Development And Testing Of The Miniature Aerial Delivery System Snowflake, Oleg A. Yakimenko, Nathan Slegers, Robyn A. Tiaden Jan 2009

Development And Testing Of The Miniature Aerial Delivery System Snowflake, Oleg A. Yakimenko, Nathan Slegers, Robyn A. Tiaden

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

This paper discusses the current status of the development of the miniature aerial delivery system to be further employed in a variety of different research projects. It starts from the overall description of the system and proceeds with the discussion of the test results performed so far. Specifically, it addresses the effects of the changing ground winds on touchdown accuracy. The paper ends with conclusions and recommendations.

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A Possible Way To Avoid Heat Death, Nitaya Buntao, Narunchara Katemee, Vladik Kreinovich Jan 2009

A Possible Way To Avoid Heat Death, Nitaya Buntao, Narunchara Katemee, Vladik Kreinovich

Departmental Technical Reports (CS)

A disturbing consequence of the traditional thermodynamics is the possibility of heat death, when the Universe arrives at the state with the largest possible value of the entropy and all the processes will stop. In this paper, we show that one possible way to avoid this consequence is to consider situations in which the entropy never attains its maximum -- and thus, the heat death state is not possible. We show that such situations can have physical sense -- e.g., they naturally appear in boostrap models.

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Towards Neural-Based Understanding Of The Cauchy Deviate Method For Processing Interval And Fuzzy Uncertainty, Vladik Kreinovich, Hung T. Nguyen Jan 2009

Towards Neural-Based Understanding Of The Cauchy Deviate Method For Processing Interval And Fuzzy Uncertainty, Vladik Kreinovich, Hung T. Nguyen

Departmental Technical Reports (CS)

One of the most efficient techniques for processing interval and fuzzy data is a Monte-Carlo type technique of Cauchy deviates that uses Cauchy distributions. This technique is mathematically valid, but somewhat counterintuitive. In this paper, following the ideas of Paul Werbos, we provide a natural neural network explanation for this technique.

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Electrical Properties Of Zno–Batio3–Zno Heterostructures With Asymmetric Interface Charge Distribution, V. M. Voora, Tino Hofmann, M. Brandt, M. Lorenz, N. Ashkenov, M. Grundmann, Mathias Schubert Jan 2009

Electrical Properties Of Zno–Batio3–Zno Heterostructures With Asymmetric Interface Charge Distribution, V. M. Voora, Tino Hofmann, M. Brandt, M. Lorenz, N. Ashkenov, M. Grundmann, Mathias Schubert

Nebraska Center for Materials and Nanoscience: Faculty Publications

We report on capacitance-voltage, current-voltage, Sawyer–Tower, and transient current switching measurements for a ZnO–BaTiO3–ZnO heterostructure deposited on (001) silicon by using pulsed laser deposition. The triple-layer structure reveals asymmetric capacitance- and current-voltage hysteresis and cycling-voltage dependent Sawyer–Tower polarization drift. We explain our findings by coupling of the ferroelectric (BaTiO3) and piezoelectric (ZnO) interface charges and parallel polarization orientation of the ZnO layers causing asymmetric space charge region formation under positive and negative bias. The transient current characteristics suggest use of this structure as nonvolatile memory device.

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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 …

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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) …

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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 …

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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 …

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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 …

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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 …

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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 …

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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 …

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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 …

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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 …

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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 …

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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 …

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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 …

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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 …

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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 …

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