Residual Stress Measurement Of 7050 Aluminum Alloy Open Die Forgings Using The Hole-Drilling Method,
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,
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,
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,
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 …
Grain Size Control In Post-Forged C263 Seamless Rolled Rings,
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 …
Analysis Of Bimetallic Adhesion And Interfacial Toughness Of Kinetic Metallization Coatings,
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,
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.
Analysis Of Hole Lifetime In Soi Mosfet Single-Photon Detector,
2013
Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011, Japan
Analysis Of Hole Lifetime In Soi Mosfet Single-Photon Detector, Dedy Septono Catur Putranto, Wei Du, Hiroaki Satoh, Atsushi Ono, Purnomo Sidi Priambodo, Djoko Hartanto, Hiroshi Inokawa
Makara Journal of Technology
Hole lifetime in the silicon-on-insulator (SOI) metal-oxide-semiconductor field-effect transistor (MOSFET) singlephoton detector was evaluated by the analysis of drain current histograms for different light intensities and substrate voltages. It was found that the peaks in the histogram corresponding to the larger number of stored holes grew as the gate bias decreased. This was attributed not to the increased light absorption efficiency or collection efficiency of the photo-generated holes, but to the prolonged hole lifetime presumably caused by the higher transverse electric field inside the body of SOI MOSFET.
Biodiesel Reactor Design With Glycerol Separation To Increase Biodiesel Production Yield,
2013
Faculty of Agriculture , Universitas Siliwangi, Tasikmalaya 46115, Indonesia
Biodiesel Reactor Design With Glycerol Separation To Increase Biodiesel Production Yield, Budy Rahmat, Imas Siti Setiasih, Roni Kastaman
Makara Journal of Technology
The study consisted of reactor design used for transesterification process, effect of glycerol separation on transesterification reaction, determination of biodiesel quality, and mass balance analysis. The reactor was designed by integrating circulated pump/stirrer, static mixer, and sprayer that intensify the reaction in the outer tank reactor. The objective was to reduce the use of methanol in excess and to shorten the processing time. The results showed that the reactor that applied the glycerol separation was able to compensate for the decreased use of the reactant methanol from 6:1 to 5:1 molar ratio, and changed the mass balance in the product, …
Development Of Seebeck-Coefficient Measurement Systems Using Kelvin-Probe Force Microscopy,
2013
Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011, Japan
Development Of Seebeck-Coefficient Measurement Systems Using Kelvin-Probe Force Microscopy, Kazutoshi Miwa, Faiz Salleh, Hiroya Ikeda
Makara Journal of Technology
Thermoelectric device is investigated by a number of researchers in order to enhance the thermoelectric efficiency. It is known that the efficiency can be improved by quantum effect. However, it is difficult to measure the thermoelectric characteristics of nanometer-scale structures. Thus a new measurement method is expected to be developed. We propose to apply Kelvin-probe force microscopy (KFM) to characterization of thermoelectric materials. KFM can locally observe surface potential of Fermi energy of a sample without touching the sample surface. In the present paper, we estimate the Seebeck coefficient of thin Si-on-insulator layers using KFM.
Recognition System Of Indonesia Sign Language Based On Sensor And Artificial Neural Network,
2013
Informatics Engineering Department, Muria Kudus University, Gondangmanis Kudus 59352, Indonesia
Recognition System Of Indonesia Sign Language Based On Sensor And Artificial Neural Network, Endang Supriyati, Mohammad Iqbal
Makara Journal of Technology
Sign language as a kind of gestures is one of the most natural ways of communication for most people in deaf community. The aim of the sign language recognition is to provide a translation for sign gestures into meaningful text or speech so that communication between deaf and hearing society can easily be made. In this research, the Indonesian sign language recognition system based on flex sensors and an accelerometer is developed. This recognition system uses a sensory glove to capture data. The sensor data that are processed into feature vector are the 5-fingers bending and the palm acceleration when …
Growth Of Crsi2 Nanostructures Using Crcl2 Powder On Si Substrates,
2013
Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011, Japan
Growth Of Crsi2 Nanostructures Using Crcl2 Powder On Si Substrates, Wen Li, Meng Erchao, Tomoji Matsushita, Shingo Oda, Daisuke Ishikawa, Kaito Nakane, Hirokazu Tatsuoka
Makara Journal of Technology
Chromium disilicide (CrSi2) nanostructures were grown by the exposure of Si (111) substrates to CrCl2 vapor in an argon gas flow at atmospheric pressure without using any metal catalyst. Dependence of the growth condition on the structural property was investigated. Hexagonal-shaped CrSi2 microrods were grown at 750 °C with 0.05 g of CrCl2. As the quantity of CrCl2 increased to 0.1 g, the bundle of CrSi2 nanowires with microrods and web-liked CrSi2 nanostructure with turning angles were grown at 750 °C and 700 °C, respectively. The preliminary discussion on the growth mechanism of CrSi2 micro- and nanostructures was carried out.
Superplasticity And Microstructural Stability In A Mg Alloy Processed By Hot Rolling And Friction Stir Processing,
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.
Electromagnetic Simulation For Thz Antenna-Coupled Microbolometers Operated At Room Temperature,
2013
Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011, Japan
Electromagnetic Simulation For Thz Antenna-Coupled Microbolometers Operated At Room Temperature, Makoto Aoki, Masanori Takeda, Norihisa Hiromoto
Makara Journal of Technology
Room-temperature terahertz (THz) detectors with higher performance are necessary for utilizing the THz wave in various sensing, spectroscopy and imaging, but even the best ones in the present are still insufficient for the practical applications. This issue is essential especially in the region around 1 THz at which there exists a large technology gap between microwave and middle-infrared. Therefore, we study to develop an antenna-coupled microbolometer to achieve a high-performance THz detector operated at a room-temperature for sensing at around 1 THz frequency wave. In this paper, we present several important features and results obtained from electromagnetic simulations, which help …
Performance Optimization Of Microbial Fuel Cell (Mfc) Using Lactobacillus Bulgaricus,
2013
Chemical Engineering Department, Engineering Faculty, Universitas Indonesia, Depok 16424, Indonesia
Performance Optimization Of Microbial Fuel Cell (Mfc) Using Lactobacillus Bulgaricus, Rita Arbianti, Tania Surya Utami, Heri Hermansyah, Deni Novitasari, Ester Kristin, Ira Trisnawati
Makara Journal of Technology
Electrical energy needs in Indonesia are expected to continue to rise. The use of petroleum as a source of energy still dominates, although oil reserves in Indonesia are increasingly being depleted. Therefore, there is a need to develop alternative sources of sustainable energy, such as microbial fuel cell (MFC). In this study, Lactobacillus bulgaricus was used as an electricity producer in a dual-chamber MFC reactor. We investigated the maximum electrical energy by varying the bacterial optical density (OD), the operational time of MFC, the reactor volume, the electrolyte solution, and the configuration of MFC reactor. In this study, the maximum …
Biological Pretreatment Of Oil Palm Frond Fiber Using White-Rot Fungi For Enzymatic Saccharification,
2013
R&D Unit for Biomaterials, Indonesian Institute of Sciences, Cibinong, Bogor 16911, Indonesia
Biological Pretreatment Of Oil Palm Frond Fiber Using White-Rot Fungi For Enzymatic Saccharification, Euis Hermiati, Sita Heris Anita, Lucky Risanto, Dyah Styarini, Yanni Sudiyani, Achmad Hanafi, Haznan Abimanyu
Makara Journal of Technology
Oil palm frond is one type of lignocellulosic biomass abundantly and daily available in Indonesia. It contains cellulose which can be converted to glucose, and further processed to produce different kinds of value –added products. The aim of this research is to study the effects of biological pretreatment of oil palm frond (OPF) fiber using Phanerochaete chrysosporium and Trametes versicolor on the enzymatic saccharification of the biomass. The OPF fiber (40-60 mesh sizes) was inoculated with cultures of the two fungi and incubated at 27 °C for 4 weeks. The samples were taken after 1, 2, 3, and 4 weeks …
Agricultural Drought Pattern In West Java Using Thermal Vegetation Index From Modis-Terra Satellite,
2013
Departement of Geography, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok 16424, Indonesia
Agricultural Drought Pattern In West Java Using Thermal Vegetation Index From Modis-Terra Satellite, Dini Daruati, Rahmatulloh Rahmatulloh, Sri Hardiyanti Purwadhi
Makara Journal of Technology
This study examines agricultural drought paddy fields in West Java. The aims of this research are to know the pattern and distribution of paddy field drought in West Java and the correlation between drought and the physical characteristics. The agricultural drought is obtained from TVI (Thermal Vegetation Index) model. TVI is derived from MODIS Terra satellite image, which is the ratio between the LST (Land Surface Temperature) and EVI (Enhanced Vegetation Index). Physical factors studied are rainfall, l slope, geomorphology, soil drainage, and irrigation areas. The most severe drought occurred in September 2006 because of El Nino, covering 806,564 ha, …
Stress Corrosion Cracking Susceptibility Of Ultrafine Grained Al-Mg-Sc Alloy,
2013
Missouri University of Science and Technology
Stress Corrosion Cracking Susceptibility Of Ultrafine Grained Al-Mg-Sc Alloy, G. R. Argade, N. Kumar, R. S. Mishra
Materials Science and Engineering Faculty Research & Creative Works
General corrosion and stress corrosion cracking (SCC) behavior of coarse grained, fine grained and ultrafine grained (UFG) AA5083 and Al-Mg-Sc-Zr alloy in different thermomechanical conditions were studied in the present work. Friction stir processing (FSP) was carried out to refine the grain size. The average grain size achieved after FSP for AA5083 was 7±3μm, whereas that for Al-4Mg-0.8Sc-0.08Zr was 0.39±0.16μm with 100% UFG microstructure. Linear polarization resistance and cyclic polarization techniques were used to study general corrosion behavior of these alloys in 3.5wt% NaCl solution. The UFG microstructure showed the highest polarization resistance (Rp) of ~93kΩ which increased to ~160kΩ …
Bacterial Growth On Metal And Non-Metal Surfaces In A Static Bioreactor,
2013
California Polytechnic State University, San Luis Obispo
Bacterial Growth On Metal And Non-Metal Surfaces In A Static Bioreactor, Rolan Yuk Loong Liong
Master's Theses
Research was conducted to observe bacterial growth on the surface of metals in a static bioreactor. Metal and non-metal samples were subjected to bacterial exposure (1 day and 9 days). The metal samples were surface treated prior to bacterial exposure. The microstructures of the surface treated samples were analyzed by optical microscopy. After exposure, the microstructures of the samples were analyzed by scanning electron microscopy (SEM). The analysis suggested that microbial attachment on the surface was related to the underlying microstructure of steel. The preferential attachment of microbes could potentially be influenced by cathodic and anodic regions created by the …
High Strain Rate Superplasticity In Friction Stir Processed Ultrafine Grained Mg-Al-Zn Alloys,
2013
Missouri University of Science and Technology
High Strain Rate Superplasticity In Friction Stir Processed Ultrafine Grained Mg-Al-Zn Alloys, A. Mohan, W. Yuan, R. S. Mishra
Materials Science and Engineering Faculty Research & Creative Works
Friction stirs processing of a rolled AZ31 alloy, and a high pressure die cast AZ91 alloy produced ultrafine grained materials with average grain size of 0.8μm and 0.5μm, respectively. Tensile testing was done in the temperature range of 210-360°C and strain rate range of 1x10-4-3x10-2s-1. Higher amounts of Β-precipitates in AZ91 thermally stabilized the microstructure up to 330°C. Friction processed ultrafine grain AZ91 exhibited high strain rate super plasticity at all tested temperatures. The best elongation of 1251% was achieved at a strain rate of 1x10-2s-1 and temperature of 330°C. The …
