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Articles 10021 - 10050 of 16761

Full-Text Articles in Engineering

Boosting Electrocatalytic Activity Of Nitrogen-Doped Graphene/Carbon Nanotube Composite For Oxygen Reduction Reaction, Yu Zhang, Jin-Song Hu, Wen-Jie Jiang, Lin Guo, Zi-Dong Wei, Li-Jun Wan Oct 2014

Boosting Electrocatalytic Activity Of Nitrogen-Doped Graphene/Carbon Nanotube Composite For Oxygen Reduction Reaction, Yu Zhang, Jin-Song Hu, Wen-Jie Jiang, Lin Guo, Zi-Dong Wei, Li-Jun Wan

Journal of Electrochemistry

Developing low-cost catalysts with high electrocatalytic activity for oxygen reduction reaction (ORR) has recently attracted much attention because the sluggish ORR currently limits the performance and commercialization of fuel cells and metal-air batteries as well. Nitrogen doped carbon materials have been considered as a promising candidate for the replacement of high-cost and scarce Pt-based catalysts although their electrocatalytic activity still needs to be much improved. In this work, an improved nitrogen-doped graphene/carbon nanotubes composite (N-rGO/CNT) was developed as an efficient ORR electrocatalyst. It was found that the ORR activity of N-rGO/CNT composite could be significantly enhanced by introducing iron in …

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Electrochemical Deposition Of Copt Alloy Thin Film And Its Abnormal Infrared Effects, Qing-Song Chen, Guo-Cong Guo, Shi-Gang Sun Oct 2014

Electrochemical Deposition Of Copt Alloy Thin Film And Its Abnormal Infrared Effects, Qing-Song Chen, Guo-Cong Guo, Shi-Gang Sun

Journal of Electrochemistry

Nanostructured CoPt alloy thin film was deposited on glassy carbon substrate (denoted as CoPt/GC) under cyclic voltammetric conditions. SEM studies demonstrated that the CoPt/GC was composed of nonuniform nanoparticles with an average size of 139 nm. The composition of the CoPt/GC was analyzed by energy dispersive X-ray spectroscopy (EDS), which depicts a Co:Pt ratio of ca. 3:5. In situ FTIR spectroscopy employing CO adsorption as a probe reaction revealed that the CoPt/GC exhibits abnormal infrared effects (AIREs). The unique anomalous IR features of CO adsorbed (COad) on CoPt/GC consist in the complete inversion of the COad IR …

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Recent Progress In Heteroatoms Doped Carbon Materials As A Catalyst For Oxygen Reduction Reaction, Wei Ding, Xue Zhang, Li Li, Zi-Dong Wei Oct 2014

Recent Progress In Heteroatoms Doped Carbon Materials As A Catalyst For Oxygen Reduction Reaction, Wei Ding, Xue Zhang, Li Li, Zi-Dong Wei

Journal of Electrochemistry

Developing catalytic materials for oxygen reduction reactions (ORR) with high performance and low cost has been one of the major challenges for large-scale applications of fuel cells. In this review, we summarize the recent progress in the heteroatoms doped carbon materials as a catalyst for the catalysis of ORR, with an emphasis on the universal origin of their catalytic mechanisms. The future prospects of the metal-free catalyst were to find precisely controlled doping methods, to explore the role of heteroatoms in the catalysis, and to generate more active catalysts with suitable nanostructure.

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Fabrication Of Pattern Of Graphene Oxide And Au Nanoparticles By Microcontanct Printing Technique, Wen-Hui Pang, Xiao-Jian Xiao, Meng-Wei Ye, Kai-Chao Deng, Jing Tang Oct 2014

Fabrication Of Pattern Of Graphene Oxide And Au Nanoparticles By Microcontanct Printing Technique, Wen-Hui Pang, Xiao-Jian Xiao, Meng-Wei Ye, Kai-Chao Deng, Jing Tang

Journal of Electrochemistry

Graphene oxide (GO) was prepared by modified Hummers method. Using the GO solution as "ink", Au nanoparticles (AuNPs) and GO were transferred to the surface of ITO substrate modified with (3-aminopropyl) triethoxysilane (APTES/ITO) in a sequence. The transferred AuNPs and GO could form a uniform and dense composite pattern which was characterized by FE-SEM and AFM. Moreover, using the APTES/ITO substrate surface potential as zero, the sequences of the surface potential were APTES>GO>Au.

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Fabrication And Characterization Of The Ni-Scsz Composite Anodes With A Cu-Lscm-Ceo2 Catalyst Layer In The Thin Film Sofc, Yao Lv, Bo Huang, Xi-Zhi Gu, Chun-Yi Hou, Yi-Xing Hu, Xiao-Yin Wang, Xin-Jian Zhu Oct 2014

Fabrication And Characterization Of The Ni-Scsz Composite Anodes With A Cu-Lscm-Ceo2 Catalyst Layer In The Thin Film Sofc, Yao Lv, Bo Huang, Xi-Zhi Gu, Chun-Yi Hou, Yi-Xing Hu, Xiao-Yin Wang, Xin-Jian Zhu

Journal of Electrochemistry

Solid oxide fuel cell (SOFC) directly operating on hydrocarbon without external reforming has the potential of greatly speeding up the application of SOFCs for transportation. In this paper, a three-layer structure anode was fabricated by tape casting and screen printing method. The addition of Cu-LSCM-CeO2 to the supported anode surface presented better performance running on H2 and ethanol. The maximum power densities were 511 and 390 mW?cm-2, respectively, running on H2 and ethanol at 750 °C. No significant degradation was observed on the anode. Consequently, the Cu-LSCM-CeO2 catalyst layer on the surface of the …

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Preparation And Electrochemical Behavior Of Pbo/Gn/Ac, Yun-Fang Gao, Yan-Ping Wang, Qiu-Shi Yao, Fu-Hua Wang, Dong-Lei Ren, Xin Xu Oct 2014

Preparation And Electrochemical Behavior Of Pbo/Gn/Ac, Yun-Fang Gao, Yan-Ping Wang, Qiu-Shi Yao, Fu-Hua Wang, Dong-Lei Ren, Xin Xu

Journal of Electrochemistry

The lead oxide/graphene/activated carbon (PbO/GN/AC) composite materials were prepared by impregnating commercial activated carbon and graphene in saturated lead nitrate solution followed by calcination. The structures and morphologies of the composite were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The results show that PbO crystals (about 200 nm) were dispersed uniformly on the surface of activated carbon and graphene. Electrochemical data indicate that the composite exhibited good electrochemical performances. The PbO/GN/AC composite possessed the higher over-potential of hydrogen evolution and the high specific capacitance of 312.6 F·g-1, while the internal resistance …

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Preparation Of Pt/Dna-Mwcnts/Gc Electrode And Its Electrocatalytic Activity Toward H2O2 Reduction, Li-Li Fan, Li-Na Wu, Zhi-Yu Qu, Dan-Feng Liu, Jun-Ming Zhang, Si-Ming Fan, You-Jun Fan Oct 2014

Preparation Of Pt/Dna-Mwcnts/Gc Electrode And Its Electrocatalytic Activity Toward H2O2 Reduction, Li-Li Fan, Li-Na Wu, Zhi-Yu Qu, Dan-Feng Liu, Jun-Ming Zhang, Si-Ming Fan, You-Jun Fan

Journal of Electrochemistry

The DNA-multi-walled carbon nanotubes (MWCNTs)/glassy carbon (GC) electrode was prepared by modifying the DNA functionalized MWCNTs composite on a GC electrode. A novel non-enzymatic H2O2 sensing electrode was fabricated by electrodepositing Pt nanoparticles on the DNA-MWCNTs/GC electrode. The modified electrodes were characterized by scanning electron microscope (SEM). The response properties of the sensing electrode to H2O2 were investigated by cyclic voltammetry and chronoamperometry. The results indicated that the sensing electrode exhibited a good linear relationship between response current and H2O2 concentration in the range of 0.04 ~ 18.07 mmol·L-1 with …

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On The Origin Of The Errors Of IK As Estimated From K-L Equation In Rotating Disk Electrode System, Wei Chen, Ling-Wen Liao, Zheng-Da He, Yan-Xia Chen Oct 2014

On The Origin Of The Errors Of IK As Estimated From K-L Equation In Rotating Disk Electrode System, Wei Chen, Ling-Wen Liao, Zheng-Da He, Yan-Xia Chen

Journal of Electrochemistry

Rotating disk electrode system is mainly used to study the kinetics of reactions whose reactants have very low solubility in the electrolyte. For an irreversible reaction, Koutecky-Levich equation (K-L Eq.) is frequently used to deduce the kinetic current ik). Since K-L Eq. is derived based on the assumption that a system should conform the steady-state diffusion conditions, the data recoded from the actual system which deviates from such a condition, great error may be induced for the ik estimated. In this work, polarization curves for oxygen reduction reaction at polycrystalline Pt electrode recorded in solutions with various …

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Electrochemical And Spectroscopic Studies Of Ethanol Oxidation On Nano-Cubic Pt Modified By Tin Adatoms, Lu Rao, Bin-Wei Zhang, Yan-Yan Li, Yan-Xia Jiang, Shi-Gang Sun Oct 2014

Electrochemical And Spectroscopic Studies Of Ethanol Oxidation On Nano-Cubic Pt Modified By Tin Adatoms, Lu Rao, Bin-Wei Zhang, Yan-Yan Li, Yan-Xia Jiang, Shi-Gang Sun

Journal of Electrochemistry

The nano-cubic Pt modified by tin (Sn) was synthesized and used to investigate the role of this adatom played in the ethanol oxidation. The onset potential of ethanol oxidation was significantly shifted negatively which can be forward about 300 mV when the coverage of Sn (θSn)was 0.9. The electrtochemical in situ FTIR result demonstrated that the amount of CO2 increased first, and then decreased with θSn increased, and reached the maximun when θSn was 0.38. Furthermore, the formation of acetic acid could be observed at very low potential (-0.05 V) after modifying Sn adatom, and the amount of acetic …

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Effect Of Plasticizer On Oxygen Permeability Of Cast Polylactic Acid (Pla) Films Determined Using Dynamic Accumulation Method, Kurniawan Yuniarto, Bruce A. Welt, Aris Purwanto, Hadi Karia Purwadaria, Ayman Abdellatief, Titi C. Sunarti, Setyo Purwanto Oct 2014

Effect Of Plasticizer On Oxygen Permeability Of Cast Polylactic Acid (Pla) Films Determined Using Dynamic Accumulation Method, Kurniawan Yuniarto, Bruce A. Welt, Aris Purwanto, Hadi Karia Purwadaria, Ayman Abdellatief, Titi C. Sunarti, Setyo Purwanto

Journal of Applied Packaging Research

Polylactic acid (PLA) is becoming an increasingly important biopolymer for packaging applications. PLA brittleness limits its applicability. This study evaluated PLA properties with increasing amounts of added polyethylene glycol (PEG) plasticizer. Oxygen transmission rate (OTR) of cast films was determined using the newly available Dynamic Accumulation (DA) method. Arrhenius temperature sensitivity of OTR and polymer Permeability was also determined. Permeability of neat PLA is 4.848 ml mm (STP)/m2 s kPa; hence, 4.84 ml mm (STP)/m2 s kPa, 4.07 ml mm (STP)/m2 s kPa and 5.42 ml mm (STP)/m2 s kPa by adding PEG 1 %, 5% …

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Polycrystalline Iii-Nitrides, Michael J. Callahan, Buguo Wang, John S. Bailey Oct 2014

Polycrystalline Iii-Nitrides, Michael J. Callahan, Buguo Wang, John S. Bailey

AFIT Patents

This invention provides a process for producing high-purity dense polycrystalline III-nitride slabs. A vessel which contains a group III-metal such as gallium or an alloy of group III-metals of shallow depth is placed in a reactor. The group III-metal or alloy is heated until a molten state is reached after which a halide-containing source mixed with a carrier gas and a nitrogen-containing source is flowed through the reactor vessel. An initial porous crust of III-nitride forms on the surface of the molten III-metal or alloy which reacts with the nitrogen-containing source and the halide-containing source. The flow rate of the …

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Cnt-Reinforced Polymer Nanocomposite By Molecular Dynamics Simulations, Yaeji Kim Oct 2014

Cnt-Reinforced Polymer Nanocomposite By Molecular Dynamics Simulations, Yaeji Kim

Open Access Dissertations

Polymer matrix composites reinforced with carbon nanotubes (CNTs) have received significant attention due to their potential for exceptional mechanical, electrical, thermal and optical properties. The enhancement of ultimate mechanical properties of CNT reinforced polymer composites is governed not just by the properties of the two phases but by dispersion of the CNTs, interactions in the interfacial region and local molecular changes in polymer due to the vicinity of the CNTs. Strong adhesive interactions between the matrix and CNT leads to good compatibility preventing the aggregation of the reinforcements and results in optimal mechanical response. Even though significant efforts have been …

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Digital Image Correlation Of Heterogeneous Deformations In Polycrystalline Material With Electron Backscatter Diffraction, Javier Esquivel Oct 2014

Digital Image Correlation Of Heterogeneous Deformations In Polycrystalline Material With Electron Backscatter Diffraction, Javier Esquivel

Open Access Theses

This work establishes the ability to conduct digital image correlation (DIC) investigations at varying length scales. DIC allows for a computational method of strain field measurements using multiple images to track random speckle patterns on material surfaces. The use of a powder silicon oxide speckle allows for high optical magnification correlation using conventional load frames. Self-assembling gold nanoparticles provide sub-micron resolution speckle patterns to study microstructure influences on deformation using scanning electron microscopy. The complex microstructure in aerospace grade aluminum and nickel-based superalloys, give rise to varied deformation fields, which can be studied using electron backscatter diffraction. Specimen preparation techniques, …

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Mode I Fatigue Delamination Onset Of Carbon Fibre Reinforced Polymer With Novel Post-Cure Throughthickness Reinforcement, Christopher John Kourloufas Oct 2014

Mode I Fatigue Delamination Onset Of Carbon Fibre Reinforced Polymer With Novel Post-Cure Throughthickness Reinforcement, Christopher John Kourloufas

Open Access Theses

A novel trough thickness reinforcement (TTR) technique, proposed by Kravchenko et al., has been tested under mode I fatigue loading conditions in order to investigate characterisation of the onset of delamination growth in unidirectional 8552/IM7. The experimental results, following standard test method ASTM D6115-13, indicate that the mode I fatigue delamination onset behaviour can be altered by the inclusion of TTR both ahead and behind the crack tip. Tests have been conducted at a wide range of maximum displacement values, corresponding to percentages of the critical fracture toughness value determined for the maternal, GIC . The results were found …

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Using A Centrifuge For Quality Control Of Pre-Wetted Lightweight Aggregate In Internally Cured Concrete, Albert E. Miller Oct 2014

Using A Centrifuge For Quality Control Of Pre-Wetted Lightweight Aggregate In Internally Cured Concrete, Albert E. Miller

Open Access Theses

Early age shrinkage of cementitious systems can result in an increased potential for cracking which can lead to a reduction in service life. Early age shrinkage cracking can be particularly problematic for high strength concretes, which are often specified due to their high strength and low permeability. However, these high strength concretes frequently exhibit a reduction in the internal relative humidity (RH) due to the hydration reaction (chemical shrinkage) and self-desiccation which results in a bulk shrinkage, termed autogenous shrinkage, which is substantial at early ages. Due to the low permeability of these concretes, standard external curing is not always …

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High-Purity Gallium Analysis By Inductively Coupled Plasma Mass Spectrometry, Kyungjean Min Oct 2014

High-Purity Gallium Analysis By Inductively Coupled Plasma Mass Spectrometry, Kyungjean Min

Open Access Theses

The mobility of Two-dimensional Electron Gas in AlGaAs/GaAs heterostructures that are grown in the Molecular Beam Epitaxy (MBE) can be increased by purification of the gallium used to grow the films. To attain 200 million cm2/Vs mobility, the impurity concentration of gallium should be reduced to below 1 ppb. The commercial 7N (99.99999%) gallium with 100 ppb total impurity is currently used in the MBE at Purdue University and is being purified by zone refining. To evaluate the commercial 7N gallium and establish the methodology for the impurity measurement after zone refining, germanium, iron, and zinc in 6N and 7N …

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Measurement Of The Responses Of Polyurethane And Confortm Foams And The Development Of A System Identification Technique To Estimate Polyurethane Foam Parameters From Experimental Impulse Responses, Vaidyanadan Sundaram Oct 2014

Measurement Of The Responses Of Polyurethane And Confortm Foams And The Development Of A System Identification Technique To Estimate Polyurethane Foam Parameters From Experimental Impulse Responses, Vaidyanadan Sundaram

Open Access Theses

Flexible polyurethane foam is the main cushioning element used in car seats. Optimization of an occupied seat's static and dynamic behavior requires models of foam that are accurate over a wide range of excitation and pre-compression conditions. Experiments were conducted to measure the response of foam over a wide range of excitation which include slowly varying uniaxial compression tests on a 3 inch cube foam sample, base excitation and impulse excitation test on a foam-mass system. The foam used was the same in all of the experiments, thus obtaining all the responses on the same foam sample which helps eliminate …

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Dissolution Rate And Mechanism Of Metals In Molten Aluminum Alloy A380, Hengyu Zhu Oct 2014

Dissolution Rate And Mechanism Of Metals In Molten Aluminum Alloy A380, Hengyu Zhu

Open Access Theses

Shot sleeve is a very easily worn out part in a high-pressure die-casting machine due to serious dissolution of the area underneath the pouring hole. It is because during a normal pouring process, the high temperature molten aluminum will impact and dissolve that area of the shot sleeve by complex chemical and physical process. Rotation experiment was carried out to H13 and four kinds of refractory metal samples. SEM and EDS pictures were taken in order to investigate the microstructure and the dissolution mechanism of these materials. This suggests a high strength niobium is an ideal material for that area …

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Solid Oxide Fuel Cell Electrolytes Produced Via Very Low Pressure Suspension Plasma Spray And Electrophoretic Deposition, James D Fleetwood Oct 2014

Solid Oxide Fuel Cell Electrolytes Produced Via Very Low Pressure Suspension Plasma Spray And Electrophoretic Deposition, James D Fleetwood

Open Access Dissertations

Solid oxide fuel cells (SOFCs) are a promising element of comprehensive energy policies due to their direct mechanism for converting the oxidization of fuel, such as hydrogen, into electrical energy. Both very low pressure plasma spray and electrophoretic deposition allow working with high melting temperature SOFC suspension based feedstock on complex surfaces, such as in non-planar SOFC designs. Dense, thin electrolytes of ideal composition for SOFCs can be fabricated with each of these processes, while compositional control is achieved with dissolved dopant compounds that are incorporated into the coating during deposition. In the work reported, sub-micron 8 mole % Y …

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Ultrasound Assisted Low-Temperature Synthesis Of Tib2 And Al3ti Particulates In Molten Aluminum, Zhiwei Liu Oct 2014

Ultrasound Assisted Low-Temperature Synthesis Of Tib2 And Al3ti Particulates In Molten Aluminum, Zhiwei Liu

Open Access Dissertations

In situ formed TiB2 and Al3Ti are two typical representatives of ceramic and intermetallic reinforcements in the in situ particulate reinforced Al composites. TiB2 particulates can be synthesized in molten Al via the mixed-salts reaction by adding mixed K2TiF6 and KBF4 salts into the Al melt at high temperatures. Al3 Ti particulates can be produced by the direct-melt reaction between solid Ti powders and liquid Al at high temperatures. Generally, a high reaction temperature is always needed to obtain both reinforcements. Some issues, however, such as high cost and burning loss …

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The Role Of Microstructure On The Combustion And Impact Behavior Of Mechanically Activated Nickel/Aluminum Reactive Composites, Benjamin Aaron Mason Oct 2014

The Role Of Microstructure On The Combustion And Impact Behavior Of Mechanically Activated Nickel/Aluminum Reactive Composites, Benjamin Aaron Mason

Open Access Dissertations

Metal-based reactive composites are a class of materials that consist of at least one metals, such as Ni/Al, that have high-energy densities and can produce significant energy output during exothermic reaction after thermal or mechanical initiation. However, conventionally these materials typically have slow reaction rates and are difficult to ignite at typical micron particle size ranges limiting their application. Therefore, mechanical activation techniques have been used to create materials with high surface areas and smaller characteristic dimensions in order to increase combustion velocity and ignition sensitivity. Their combustion and mechanical impact behavior is being studied to develop the understanding needed …

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Control Of Morphology Al-Fe-Si Phase In Al-Si-Cu Hypoeutectic Alloy, Meng Wang Oct 2014

Control Of Morphology Al-Fe-Si Phase In Al-Si-Cu Hypoeutectic Alloy, Meng Wang

Open Access Dissertations

Aluminum-Silicon (Al-Si) alloys are one of the most versatile aluminum alloys. Iron is considered one of the most harmful elements in Al-Si diecasting alloy because its presence leads to the precipitation of many AlFeSi intermetallic phases and unacceptable mechanical properties, such as reduction in ductility. Thus controlling the fraction and morphology of AlFeSi phase, especially the β-AlFeSi phase is an important way to improve the ductility of Al-Si die casting alloys. ^ In this dissertation, thermodynamics calculation of AlFeSi phase formation and fraction change during solidification process were conducted using Thermo-Calc software. A series of experiments, including adjusting cooling rates, …

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Nano-Modification For High Performance Cement Composites With Cellulose Nanocrystals And Carbon Nanotubes, Yizheng Cao Oct 2014

Nano-Modification For High Performance Cement Composites With Cellulose Nanocrystals And Carbon Nanotubes, Yizheng Cao

Open Access Dissertations

One of the new engineering frontiers is the exploration of infrastructure materials with novel combinations of properties that break traditional paradigms. The goal of this study is to utilize two different nano-fibers, cellulose nanocrystals (CNCs) and carbon nanotubes (CNTs) to modify the nanoscale structures of cement composites and thereby improve the performance at the macro-level. This study also evaluates the mechanism behind the modification, since fiber bridging, the most common reinforcing mechanism for fiber-reinforced composites, cannot be simply applied because CNCs are too short to bridge cracks in cement composites. ^ The mechanical tests show an increase in the flexural …

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Effects Of Energetic Irradiation On Materials And Devices Based On Graphene And Topological Insulators, Isaac Childres Oct 2014

Effects Of Energetic Irradiation On Materials And Devices Based On Graphene And Topological Insulators, Isaac Childres

Open Access Dissertations

This report focuses on the optical and electronic properties of graphene and topological insulators and how these Dirac fermion systems interact with energetic irradiation. We first present data exploring the effects of electron-beam and oxygen plasma induced disorder on the electronic properties and Raman spectra of graphene. These initial investigations were important for relating Raman peak intensities and weak localization features to each other and to an average disorder length in graphene, LD. ^ We then integrate gate-effect measurements into the Raman spectroscopy study to fully explore the relationships between carrier density, disorder and Raman spectrum signatures. We …

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A Regression Approach For Estimation Of Anthropogenic Heat Flux Based On A Bottom-Up Air Pollutant Emission Database, Sanghyun Lee, Stuart A. Mckeen, David J. Sailor Oct 2014

A Regression Approach For Estimation Of Anthropogenic Heat Flux Based On A Bottom-Up Air Pollutant Emission Database, Sanghyun Lee, Stuart A. Mckeen, David J. Sailor

Mechanical and Materials Engineering Faculty Publications and Presentations

A statistical regression method is presented for estimating hourly anthropogenic heat flux (AHF) using an anthropogenic pollutant emission inventory for use in mesoscale meteorological and air-quality modeling. Based on bottom-up AHF estimated from detailed energy consumption data and anthropogenic pollutant emissions of carbon monoxide (CO) and nitrogen oxides (NOx) in the US National Emission Inventory year 2005 (NEI-2005), a robust regression relation between the AHF and the pollutant emissions is obtained for Houston. This relation is a combination of two power functions (Y = aXb) relating CO and NOx emissions to AHF, giving a determinant …

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Passive Phase Separation Of Microgravity Bubbly Flows Using Conduit Geometry, Ryan M. Jenson, Andrew Paul Wollman, Mark M. Weislogel, Lauren Sharp, Robert Green, Peter J. Canfield, Jörg Klatte, Michael E. Dreyer Oct 2014

Passive Phase Separation Of Microgravity Bubbly Flows Using Conduit Geometry, Ryan M. Jenson, Andrew Paul Wollman, Mark M. Weislogel, Lauren Sharp, Robert Green, Peter J. Canfield, Jörg Klatte, Michael E. Dreyer

Mechanical and Materials Engineering Faculty Publications and Presentations

The ability to separate liquid and gas phases in the absence of a gravitational acceleration has proven a challenge to engineers since the inception of space exploration. Due to our singular experience with terrestrial systems, artificial body forces are often imparted in multiphase fluid systems aboard spacecraft to reproduce the buoyancy effect. This approach tends to be inefficient, adding complexity, resources, and failure modes. Ever present in multiphase phenomena, the forces of surface tension can be exploited to aid passive phase separations where performance characteristics are determined solely by geometric design and system wettability. Said systems may be readily designed …

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Investigation Of Microstructural Alterations In M50 And 52100 Steel Using Nanoindentation, Kristin R. Paulson Oct 2014

Investigation Of Microstructural Alterations In M50 And 52100 Steel Using Nanoindentation, Kristin R. Paulson

Open Access Theses

Bearing steels are used in rolling elements and are designed to withstand heavy loads for an extended period of time. At the end of life, microstructural alterations within the material have been observed and are linked to failure. In this study, a three ball-on-rod fatigue tester was used to test M50 and 52100 steel cylindrical rods at differing loads of 4.0 GPa, 4.5 GPa, and 5.0 GPa and in lubricated and unlubricated conditions to 10 8 cycles in an attempt to produce microstructural alterations. Microstructural alterations characterized as butterflies were observed and investigated further in two M50 samples that were …

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Simulation Studies Of Organic Solar Cell Structure And Morphology On The Device Efficiency, Satish Kumar Reddy Kota Oct 2014

Simulation Studies Of Organic Solar Cell Structure And Morphology On The Device Efficiency, Satish Kumar Reddy Kota

Electrical & Computer Engineering Theses & Dissertations

Solar cells based on organic materials offer several advantages over the traditional solar cells made with inorganic materials. These include a lower impact on nature, smaller weight, the avoidance of cleanrooms for their production, their flexibility which makes it possible to wrap or coat them on objects with varying shapes and geometries, and most significantly their ability to produce electricity in diffuse'd light which is a distinct advantage over conventional solar cells. Organic solar cells have their own disadvantage of very low efficiencies as compared to inorganic solar cells. The morphology and structure of the organic solar cells plays a …

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Pump Design And Development For High Shear Grout Mixing Applications, John Kijak, David Kennedy Sep 2014

Pump Design And Development For High Shear Grout Mixing Applications, John Kijak, David Kennedy

Conference Papers

No abstract provided.

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Performance Of Columnar 7-8 Wt% Ysz Coatings On Platinum Aluminide Bondcoats, Christopher Petorak Sep 2014

Performance Of Columnar 7-8 Wt% Ysz Coatings On Platinum Aluminide Bondcoats, Christopher Petorak

Thermal Barrier Coatings IV

No abstract provided.

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