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Observation Of Photovoltaic Effect And Single-Photon Detection In Nanowire Silicon Pn-Junction, Arief Udhiarto, Sri Purwiyanti, Daniel Moraru, Takeshi Mizuno, Michiharu Tabe 2013 Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011, Japan

Observation Of Photovoltaic Effect And Single-Photon Detection In Nanowire Silicon Pn-Junction, Arief Udhiarto, Sri Purwiyanti, Daniel Moraru, Takeshi Mizuno, Michiharu Tabe

Makara Journal of Technology

We study nanowire silicon pin and pn-junctions at room and low temperature. Photovoltaic effects are observed for both devices at room temperature. At low temperature, nanowire pn-junction devices show their ability to detect single photon. This ability was not been observed for pin devices. Phosphorus-boron dopant cluster in the depletion region is considered to have the main role for single-photon detection capability. Fundamental mechanism of dopant-based single-photon detection in nanowire pn-junction is described in details.


Influences Of Surface Morphology Of Nanostructured Rutile Tio2 Nanorods/Nanoflowers As Photoelectrode On The Performance Of Dye-Sensitized Solar Cell, Mohd Khairul Bin Ahmad, Kenji Murakami 2013 Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011, Japan

Influences Of Surface Morphology Of Nanostructured Rutile Tio2 Nanorods/Nanoflowers As Photoelectrode On The Performance Of Dye-Sensitized Solar Cell, Mohd Khairul Bin Ahmad, Kenji Murakami

Makara Journal of Technology

Aligned Rutile TiO2 nanorods (r-TNRs) and TiO2 nanoflowers (r-TNFs) were successfully prepared by hydrothermal method. Using hydrochloric acid (HCl) as chelating agent and titanium butoxide (TBOT) as precursor, aligned r-TNRs with r-TNFs were successfully growth onto fluorine-doped tin oxide (FTO) with different morphologies. The influences of surface morphologies to the rutile based Dye-sensitized solar cell (DSC) efficiency are discussed. The highest lightto- electric energy conversion efficiency, 1.80% is achieved using different concentration under simulated solar light illumination of 100 mWcm-2 (1.5 AM).


Improvement In Performance Of Zno Based Dsc Prepared By Spraying Method, Rangga Winantyo, Devinda Liyanage, Kenji Murakami 2013 Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011, Japan

Improvement In Performance Of Zno Based Dsc Prepared By Spraying Method, Rangga Winantyo, Devinda Liyanage, Kenji Murakami

Makara Journal of Technology

This paper reports the effect of TiCl4 on the performance of ZnO based DSC. ZnO was used due to its stability against photo-corrosion and photochemical properties similar to TiO2. Thin films of nanocrystalline ZnO were deposited on transparent conducting oxide glass using spray method. The ZnO films were treated using TiCl4. The cell’s efficiency was found to be 2.5% with TiCl4 post-treatment and 1.9% without TiCl4 post-treatment.


Determining The Air Gap Length Of An Axial Flux Wound Rotor Synchronous Generator, Abdul Multi, Iwa Garniwa, Uno Bintang Sudibyo 2013 Department of Electrical Engineering, Faculty of Engineering, Universitas Indonesia, Depok 16424, Indonesia

Determining The Air Gap Length Of An Axial Flux Wound Rotor Synchronous Generator, Abdul Multi, Iwa Garniwa, Uno Bintang Sudibyo

Makara Journal of Technology

The air gap length of the designed axial flux wound rotor (AFWR) synchronous generator is determined properly according to the design parameters. One of the distinct advantages of an axial flux (AF) machine is its adjustable air gap. An AF generator’s performance might be controlled by adjusting its air gap. The designed generator has a smallscale capacity that has 1 kW, 380 V, and 50 Hz. The windings are laid into slots made from laminated core. The slots are carved in the face of the stator and rotors. The generator has a single-double-sided slotted wound stator sandwiched between twin rotors. …


Production Optimization For Plan Of Gas Field Development Using Marginal Cost Analysis, Suprapto Soemardan, Widodo Wahyu Purwanto, Arsegianto Arsegianto 2013 Chemical Engineering Department, Faculty of Engineering, Universitas Indonesia, Depok 16424, Indonesia

Production Optimization For Plan Of Gas Field Development Using Marginal Cost Analysis, Suprapto Soemardan, Widodo Wahyu Purwanto, Arsegianto Arsegianto

Makara Journal of Technology

Gas production rate is one of the most important variables affecting the feasibility plan of gas field development. It take into account reservoir characteristics, gas reserves, number of wells, production facilities, government take and market conditions. In this research, a mathematical model of gas production optimization has been developed using marginal cost analysis in determining the optimum gas production rate for economic profit, by employing the case study of Matindok Field. The results show that the optimum gas production rate is mainly affected by gas price duration and time of gas delivery. When the price of gas increases, the optimum …


Effect Of Zinc Galvanization On The Microstructure And Fracture Behavior Of Low And Medium Carbon Structural Steels, Ignatius C. Okafor, Ronald J. O'Malley, Kaushal R. Prayakarao, Heshmat A. Aglan 2013 Missouri University of Science and Technology

Effect Of Zinc Galvanization On The Microstructure And Fracture Behavior Of Low And Medium Carbon Structural Steels, Ignatius C. Okafor, Ronald J. O'Malley, Kaushal R. Prayakarao, Heshmat A. Aglan

Materials Science and Engineering Faculty Research & Creative Works

Microstructure and fracture behavior of ASTM 572 Grade 65 steels used for wind tower applications have been studied. Steels of two carbon level chemistries designed for this grade were used in the study. Fracture toughness of the steels was studied using 3-point bend test on samples coated with zinc and not coated with zinc. Lower carbon steel showed higher resistance to fracture than medium carbon steel after zinc galvanization. SEM study suggests that zinc and zinc bath additives that migrated to crack tips are responsible for the loss in ductility. The phenomenon of Liquid Metal Embrittlement (LME) is suggested to …


Achieving High Strength And High Ductility In Friction Stir-Processed Cast Magnesium Alloy, Wei Yuan, Sushanta K. Panigrahi, Rajiv S. Mishra 2013 Missouri University of Science and Technology

Achieving High Strength And High Ductility In Friction Stir-Processed Cast Magnesium Alloy, Wei Yuan, Sushanta K. Panigrahi, Rajiv S. Mishra

Materials Science and Engineering Faculty Research & Creative Works

Friction stir processing (FSP) is emerging as an effective tool for microstructural modification and property enhancement. As-cast AZ91 magnesium alloy was friction stir processed with one-pass and two-pass to examine the influence of processing conditions on microstructural evolution and corresponding mechanical properties. Grain refinement accompanied with development of strong basal texture was observed for both processing conditions. Ultrafine-grained (UFG) AZ91 was achieved under two-pass FSP with fine precipitates distributed on the grain boundary. The processed UFG AZ91 exhibited a high tensile strength of ∼435 MPa (117 pct improvement) and tensile fracture elongation of ∼23 pct. The promising combination of strength …


Influence Of Strain And Strain Rate On Microstructural Evolution During Superplasticity Of Mg-Al-Zn Sheet, A. Mohan, S. K. Panigrahi, R. S. Mishra, R. Verma 2013 Missouri University of Science and Technology

Influence Of Strain And Strain Rate On Microstructural Evolution During Superplasticity Of Mg-Al-Zn Sheet, A. Mohan, S. K. Panigrahi, R. S. Mishra, R. Verma

Materials Science and Engineering Faculty Research & Creative Works

Strain-induced abnormal grain growth was observed along the gage length during high-temperature uniaxial tensile testing of rolled Mg-Al-Zn (AZ31) sheet. Effective strain and strain rates in biaxial forming of AZ31 sheets also affected the nature of grain growth in the formed sheet. For the uniaxial testing done at 400 C and a strain rate of 10-1 s-1, abnormal grain growth was prevalent in the gage sections that experienced true strain values between 0.2 and 1.0. Biaxial forming of AZ31 at 5 x 10 -2 s-1 and 400 C also exhibited abnormal grain growth at the cross …


High-Speed Imaging Of A Bulk Metallic Glass During Uniaxial Compression, Wendelin Wright, Rachel R. Byer, Xiaojun Gu 2013 Bucknell University

High-Speed Imaging Of A Bulk Metallic Glass During Uniaxial Compression, Wendelin Wright, Rachel R. Byer, Xiaojun Gu

Faculty Journal Articles

High-speed imaging directly correlates the propagation of a particular shear band with mechanical measurements during uniaxial compression of a bulk metallic glass. Imaging shows shear occurs simultaneously over the entire shear plane, and load data, synced and time-stamped to the same clock as the camera, reveal that shear sliding is coincident with the load drop of each serration. Digital image correlation agrees with these results. These data demonstrate that shear band sliding occurs with velocities on the order of millimeters per second. Fracture occurs much more rapidly than the shear banding events, thereby readily leading to melting on fracture surfaces.


Microstructure And Mechanical Properties Of A Friction Stir Processed Ti-6al-4v Alloy, Jianqing Su, Jiye Wang, Rajiv S. Mishra, Ray Xu, John A. Baumann 2013 Missouri University of Science and Technology

Microstructure And Mechanical Properties Of A Friction Stir Processed Ti-6al-4v Alloy, Jianqing Su, Jiye Wang, Rajiv S. Mishra, Ray Xu, John A. Baumann

Materials Science and Engineering Faculty Research & Creative Works

Friction stir processing (FSP) trials were performed on 2mm-thick Ti-6Al-4V sheets using various processing parameters including tool rotational speed (800-1000RPM) and tool traverse speed (1-4IPM). A processing window was established with the W-1% La2O3 tool to produce defect-free friction stir processed (FSP'd) materials. The stir zone (SZ) material of the FSP'd samples showed a fully Β transformed microstructure characterized by typical basket-weave lamellar α/Β structure. The prior Β grains in the SZs contained multiple α variants, and the average sizes ranged from 12μm to 38μm influenced by the processing parameters. Based on metallurgical evaluation, the microstructural evolution …


Mechanical Properties And Microstructures Of Incoloy 909 Rolled Rings Subjected To A Modified Forging Cycle, Colin Lee Elliott Glaves 2013 California Polytechnic State University-- San Luis Obispo

Mechanical Properties And Microstructures Of Incoloy 909 Rolled Rings Subjected To A Modified Forging Cycle, Colin Lee Elliott Glaves

Materials Engineering

The microstructure of rolled rings of Incoloy 909 nickel-iron-cobalt superalloy subjected to a standard customer solution and aging treatment exhibited unacceptably large grains. Samples cut from a failed ring were mounted and polished for analysis. The samples were etched with a modified Kalling’s waterless reagent and metallographic analysis was done to identify characteristic large grain structures distributed among the desired smaller grain structures. The large grains were identified and noted for comparison to later samples. Two test rings were forged out of Incoloy 909 using revised forging procedures involving reduced soak temperatures before each forging step. Metallographic samples were cut …


The Effects Of Heat Treatment On The Grain Growth, Phase Evolution, And Hardness Of Newly Developed Steel-Based Hardfacing Alloys For Industrial Applications, Renee Kuzniar 2013 California Polytechnic State University - San Luis Obispo

The Effects Of Heat Treatment On The Grain Growth, Phase Evolution, And Hardness Of Newly Developed Steel-Based Hardfacing Alloys For Industrial Applications, Renee Kuzniar

Materials Engineering

Steel-based hardfacing alloys are welded onto the outside diameter of tool joints in three beads with a slight overlap between welds for underground drilling to prolong the tool joints’ life. Current hardfacing alloys have a shortened life due to cracks occurring in neighboring weld beads. To decrease cracking, the effects of composition and heat treatment on the microstructure was investigated on five alloys. Five small arc-melt circular ingots roughly 1.4 x 0.3 inches were produced. Each sample had varying amounts of C, B, Cr, Mn, Mo, Nb, Si, Ti, V, and W. The carbon levels in the alloys were .91wt%, …


Grain Size Control In Post-Forged C263 Seamless Rolled Rings, Christopher Smith 2013 California Polytechnic State University - San Luis Obispo

Grain Size Control In Post-Forged C263 Seamless Rolled Rings, Christopher Smith

Materials Engineering

Seamless rolled rings of C263 superalloy were forged by Carlton Forge Works in Paramount, CA and sectioned for mechanical testing. The as-forged ring sections were then machined into tensile samples. To simulate cold working done after Carlton’s forging process, the C263 tensile samples were strained using an Instron tensile tester to 1, 3, 5, 7, and 9% plastic strain. These tensile samples were then solution treated at 2100°F for 30 minutes and water quenched before being aged at 1470°F for 8 hours and air cooled, following Carlton Forge Works’ heat treatment process. The gauge length sections were metallographically prepared and …


Residual Stress Measurement Of 7050 Aluminum Alloy Open Die Forgings Using The Hole-Drilling Method, Alexandra Viksne 2013 California Polytechnic State University - San Luis Obispo

Residual Stress Measurement Of 7050 Aluminum Alloy Open Die Forgings Using The Hole-Drilling Method, Alexandra Viksne

Materials Engineering

Open die forged 7050 aluminum alloy has residual stresses that can be measured by the hole-drilling method following standard ASTM E837-01. Weber Metals (Paramount, CA) assumes that the stress is uniform throughout the thickness of an open die forged plate. Four different stress relieved 7050 aluminum samples were tested to confirm if the measurements by the hole-drilling method at the surface of a plate is indicative of the stress throughout. The different stress relief methods included: two water quenched samples at temperature ranges of 60°-90°F and 120°-130°F and two samples plastically deformed by forging at room temperature 1% and 3%. …


Evaluation Of High Phosphorus Electroless Nickel Platings To Protect Carbon Steel Heat Exchangers In Seawater Service, Nathan Brink 2013 California Polytechnic State University - San Luis Obispo

Evaluation Of High Phosphorus Electroless Nickel Platings To Protect Carbon Steel Heat Exchangers In Seawater Service, Nathan Brink

Materials Engineering

The purpose of this project was to determine the suitability of using a high phosphorus electroless nickel (HPEN) coating to prevent corrosion in carbon steel heat exchangers in seawater service. 1 in. x 4 in. samples were cut from ¼ in. SA-516-70 pressure vessel plate, pickled to remove mill scale, dressed with 300 grit sand paper and sent out for plating with 2 mils of HPEN. Due to a clerical error during plating, samples were plated to a significantly lesser extent than requested. Samples were plated with approximately 0.6 mils of HPEN versus the 2 mils requested, however this was …


Effect Of Carbon On Primary Alpha Percentage In Ti-6al-4v As Temperature Approaches The Beta Transus, Kyle Savage 2013 California Polytechnic State University - San Luis Obispo

Effect Of Carbon On Primary Alpha Percentage In Ti-6al-4v As Temperature Approaches The Beta Transus, Kyle Savage

Materials Engineering

Some Ti-6Al-4V forgings require a specific amount of α phase known as primary α in the finished product. The percentage of primary α is dependent on how close to the beta transus temperature forging is conducted. The beta transus temperature is affected by certain alloying elements. Carbon is one of the elements known to increase the beta transus temperature. Since each Ti-6Al-4V ingot contains varying amounts of carbon, testing on a variety of chemistries needs to be conducted. Cubes approximately 0.5 inches from low, medium, and high carbon chemistries were heat treated at temperatures below the beta transus in 18 …


Evaluation Of Forging Strain For Maximum Grain Size In Open-Die Forged 6061 Aluminum, Eric Strehl 2013 California Polytechnic State University - San Luis Obispo

Evaluation Of Forging Strain For Maximum Grain Size In Open-Die Forged 6061 Aluminum, Eric Strehl

Materials Engineering

In an effort to maximize grain growth of open-die forged 6061 aluminum alloy parts, samples from three of Weber Metals’s suppliers (Hidal Co-Almex USA Inc., TST Inc., and Vista Metals Corp.; to be called Supplier H, Supplier T, Supplier V respectively) were cut into cylinders with diameters of 0.75˝ and heights of 2˝, and put through a simulated forging process and heat treatment. It is possible that additional alloying elements may be promoting or inhibiting grain growth in the final part. Maximizing grain growth for aluminum alloy parts results in improved resistance to intergranular corrosion. Samples from each vendor had …


Analysis Of Bimetallic Adhesion And Interfacial Toughness Of Kinetic Metallization Coatings, Alec D. Guraydin 2013 California Polytechnic State University, San Luis Obispo

Analysis Of Bimetallic Adhesion And Interfacial Toughness Of Kinetic Metallization Coatings, Alec D. Guraydin

Master's Theses

Due to their ability to confer enhanced surface properties without compromising the properties of the substrate, coatings have become ubiquitous in heavy industrial applications for corrosion, wear, and thermal protection, among others. Kinetic Metallization (KM), a solid-state impact consolidation and coating process, is well-suited for depositing industrial coatings due to its versatility, low substrate heat input, and low cost. The ability of KM coatings to adhere to the substrate is determined by the quality of the interface. The purpose of this study is to develop a model to predict the interfacial quality of KM coatings using known coating and substrate …


An Experimentally Generated Constitutive Model For Peak Stress (Σ_Peak) In Compression Samples, Kevin Mathew Lopez Galang 2013 California Polytechnic State University, San Luis Obispo

An Experimentally Generated Constitutive Model For Peak Stress (Σ_Peak) In Compression Samples, Kevin Mathew Lopez Galang

Master's Theses

The hot working behavior of AISI 1018 steel was studied by hot-compression deformation tests on the Gleeble 1500 thermo-mechanical simulator at true strain values of -0.143 and -0.405, true strain rate values of 0.01 and 0.1, and working temperatures of 900°C and 1000°C. The tests show that a lower working temperature and lower true strain value results in a greater maximum compressive force. The apparent activation energy Qapp was calculated by using the Zener-Hollomon parameter combined with the low stress law. Qapp ­was calculated to be 311 kJ mol-1 K-1.


Superplasticity And Microstructural Stability In A Mg Alloy Processed By Hot Rolling And Friction Stir Processing, V. Jain, R. S. Mishra, R. Verma, E. Essadiqi 2013 Missouri University of Science and Technology

Superplasticity And Microstructural Stability In A Mg Alloy Processed By Hot Rolling And Friction Stir Processing, V. Jain, R. S. Mishra, R. Verma, E. Essadiqi

Materials Science and Engineering Faculty Research & Creative Works

The superplastic behavior of a Mg-1.2 Zn-1.7 Y-0.53 Al-0.27 Mn alloy sheet processed by hot rolling and friction stir processing (FSP) was investigated. The kinetics of superplastic deformation were compared with Mg-3 Al-1 Zn and other Mg-Zn-Y alloys processed by different methods. The FSP Mg-1.2 Zn-1.7 Y-0.53 Al-0.27 Mn alloy exhibits slower kinetics of deformation compared with other alloys. The microstructural stability of the FSP Mg-1.2 Zn-1.7 Y-0.53 Al-0.27 Mn alloy is better than the Mg-3 Al-1 Zn alloy because of the presence of different types of precipitates. © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.


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