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Full-Text Articles in Engineering

Designing An Articulation-Agreement Database For The College Of Science And Engineering And Technology Advising Center, Stephanie Fasen, Susan Hendley, Tim Pham, Danish Zaman Aug 2014

Designing An Articulation-Agreement Database For The College Of Science And Engineering And Technology Advising Center, Stephanie Fasen, Susan Hendley, Tim Pham, Danish Zaman

Journal of Undergraduate Research at Minnesota State University, Mankato

During their academic careers, some college students transfer to different universities. To allow students to transfer seamlessly to other colleges, advisors at Minnesota universities create articulation agreements that list the classes that transfer between two universities. To use these documents, students and advisors must search through binders to find the correct articulation agreement and then manually review it. This is a time-consuming process for both students and advisors. To make this information more accessible, we created a web-based database that instantly produces a list of equivalent classes for majors offered at Minnesota St ate University, Mankato (MSU) and other Minnesota …

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Effects Of Thermal Boundary Conditions During Finite Element Modeling Of Physical Vapor Transport, Wade Luhman Aug 2014

Effects Of Thermal Boundary Conditions During Finite Element Modeling Of Physical Vapor Transport, Wade Luhman

Journal of Undergraduate Research at Minnesota State University, Mankato

Physical vapor transport (PVT) is a material processing method commonly used to produce different types of semiconductor materials. Computer modeling of PVT is important to understand the fundamentals of the processing method. Due to the large amount of computer processing power and storage needed to solve the computer models many of the previously solved simulations have been simplified to efficiently utilize computer usage. Previous PVT computer simulations of mercurous chloride (Hg2Cl2) have assumed constant temperature profiles on the source and crystal substrate for simplicity. These simulations were performed using the FIDAP computational fluid dynamics software package. In this research the …

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Racial Disparities In Access To Community Water Supply Service In Wake County, North Carolina, Jacqueline Macdonald Gibson, Nicholas Defelice, Daniel Sebastian, Hannah Leker Aug 2014

Racial Disparities In Access To Community Water Supply Service In Wake County, North Carolina, Jacqueline Macdonald Gibson, Nicholas Defelice, Daniel Sebastian, Hannah Leker

Frontiers in Public Health Services and Systems Research

Anecdotal evidence suggests that historically African American communities on the fringes of cities and towns in North Carolina have been systematically denied access to municipal drinking water service. This paper presents the first statistical analysis of the role of race in determining water access in these fringe areas, known as extraterritorial jurisdictions. Using publicly available property tax data, we quantified the percentage of residences with municipal water service in each census block in Wake County (the second-largest by population in North Carolina). Using the resulting water service maps plus 2010 U.S. Census data, we employed a logistic regression to assess …

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Fluid Properties In The Formation Of High-Grade Iron Ore In Northern Minnesota, Elizabeth Drommerhausen Aug 2014

Fluid Properties In The Formation Of High-Grade Iron Ore In Northern Minnesota, Elizabeth Drommerhausen

Journal of Undergraduate Research at Minnesota State University, Mankato

The Mesabi Iron Range in Northern Minnesota has been a major producer of iron ore for over 100 years. Production has been from the 1.85 – billion-year –old Biwabik Iron Formation, an iron-rich sedimentary rock that is tilted gently to the south. Most of the known high-grade ore lies near the surface and has been already mined. Determining whether more high-grade ore may lie at depth could have significant economic impact on the mining industry in northern Minnesota. To evaluate the likelihood of finding more high-grade iron ore deeper underground, it is important to determine the source of the fluids …

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Instrumentation To Monitor Bridge Foundation On The Crosstown Project, Brian Welch Aug 2014

Instrumentation To Monitor Bridge Foundation On The Crosstown Project, Brian Welch

Journal of Undergraduate Research at Minnesota State University, Mankato

The Crosstown Bridge Monitoring Project is located at the intersection of Highway 62 and Interstate I35W a few miles south and west of downtown Minneapolis. The bridge being evaluated is at a railroad overpass located midway along the Crosstown expansion. This research project involved placing instrumentation on the bridge foundation in order to measure the change in the foundation loading during the course of the construction project. For several years there have been questions pertaining to the forces in the pile foundations that support highway embankments. This project placed strain gages on the pile foundations in order to monitor these …

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Boundary Knot Method Solution Of Helmholtz Problems With Boundary Singularities, De-Jian Shen, Ji Lin, Wen Chen Aug 2014

Boundary Knot Method Solution Of Helmholtz Problems With Boundary Singularities, De-Jian Shen, Ji Lin, Wen Chen

Journal of Marine Science and Technology–Taiwan

This paper proposes a boundary knot method (BKM) formulation in conjunction with the singularity subtraction technique to solve Helmholtz problems with boundary singularities. The solution breaks down into the singular solution and the regular solution. The singular solution is derived analytically and satisfies the governing equation and the corresponding boundary conditions containing singularities. Then the regular solution is approximated by the BKM. Numerical results demonstrate the accuracy and efficiency of the proposed technique.

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Behaviors Of Large-Scale Driven Pc Piles, Shih-Tsung Hsu Aug 2014

Behaviors Of Large-Scale Driven Pc Piles, Shih-Tsung Hsu

Journal of Marine Science and Technology–Taiwan

This study developed a numerical method for evaluating ground movements while a pile is being driven and obtained a comprehensive load-displacement curve for a driven pile. The tested pile exhibited a larger scale than those tested in previous studies, and was penetrated into a considerable depth of the stratum. Numerical results revealed that both the ground movement and residual force caused by the pile driving was able to be analyzed using the proposed numerical procedure. Although the load applied to the tested piles differed from that determined by numerically analyzing incremental pile displacement, the load-displacement behavior of the piles calculated …

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Optimization Of Electrical Discharge Machining Parameters For Niti Shape Memory Alloy By Using The Taguchi Method, Saeed Daneshmand, Ehsan Farahmand Kahrizi, Ali Akbar Lotfineyestanak, Vahid Monfared Aug 2014

Optimization Of Electrical Discharge Machining Parameters For Niti Shape Memory Alloy By Using The Taguchi Method, Saeed Daneshmand, Ehsan Farahmand Kahrizi, Ali Akbar Lotfineyestanak, Vahid Monfared

Journal of Marine Science and Technology–Taiwan

Electrical discharge machining (EDM) is among the most essential nontraditional machining processes. Material removal rate (MRR) and surface roughness are the two main parameters applied in this method. A desired surface roughness can be achieved at the maximal MRR by selecting the optimal input parameters. Because of the mechanical properties and hardness of shape-memory nickel titanium (NiTi) alloy, material can be removed using an EDM method. NiTi alloy is widely used in marine science and aerospace industries. Surface roughness is a critical parameter affecting the machining of this alloy. This study examined the effect the input parameters (pulse current, gap …

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Added Mass Computation For Control Of An Open-Frame Remotely-Operated Vehicle: Application Using Wamit And Matlab, You-Hong Eng, Cheng-Siong Chin, Michael Wai-Shing Lau Aug 2014

Added Mass Computation For Control Of An Open-Frame Remotely-Operated Vehicle: Application Using Wamit And Matlab, You-Hong Eng, Cheng-Siong Chin, Michael Wai-Shing Lau

Journal of Marine Science and Technology–Taiwan

In this paper, numerical modeling and testing of a complexshaped remotely-operated vehicle (ROV) are shown. The paper emphasizes on systematic modeling of hydrodynamic added mass using computational fluid dynamic software WAMITTM on the open frame ROV that is not commonly applied in practice. From initial design and prototype testing, a small-scale test using a free-decaying experiment is used to verify the theoretical models obtained from WAMITTM. Simulation results have shown to coincide with the experimental tests. The proposed method is able to determine the hydrodynamic added mass coefficients of the open frame ROV.

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Geometric Solution In Progressive Collapse Analysis Of Hull Girder, Ertekin Bayraktarkatal, Gökhan Tansel Tayyar Aug 2014

Geometric Solution In Progressive Collapse Analysis Of Hull Girder, Ertekin Bayraktarkatal, Gökhan Tansel Tayyar

Journal of Marine Science and Technology–Taiwan

This paper presents a calculation model for stiffened plates to determine the ultimate strength of ship hull girders from their curvatures using a geometrical approach. The present study employed Smith’s method, in which the cross-section is divided into smaller elements consisting of a stiffener(s) and attached plating. The strength of beam-columns and stiffened plates was obtained using an iterative numerical approach. The deflection curve was evaluated using the curvature values directly instead of by solving differential equations. The deflection curve was taken as an assembly of chains of circular arcs. The ultimate strength of the hull girder of a 1/3 …

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Intelligent Dynamic Acquisition Learning Fuzzy Modeling Systems Design, Hsuan-Ming Feng, Ching-Yi Chen Aug 2014

Intelligent Dynamic Acquisition Learning Fuzzy Modeling Systems Design, Hsuan-Ming Feng, Ching-Yi Chen

Journal of Marine Science and Technology–Taiwan

Secretary General, Taiwan Group on Earth Observations, Taiwan, R.O.C

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Reversing Sensitization Of Naturally Exfoliated 5456-H116 Aluminum Alloys, Ren-Yu Chen, Cheng-Chyuan Lai Aug 2014

Reversing Sensitization Of Naturally Exfoliated 5456-H116 Aluminum Alloys, Ren-Yu Chen, Cheng-Chyuan Lai

Journal of Marine Science and Technology–Taiwan

5456-H116 Al-Mg alloy has been broadly used in the U.S. Navy in order to meet the demand of reducing ship hull weight while considering high specific strength, corrosion resistance, and weldability. A particular concern of these alloy is sensitization, which causes it to be sensitized when highly anodic β phase (Al3Mg2) is precipitated at grain boundaries especially in service exceeding 65~200°C, leading to intergranular corrosion (IGC), exfoliation and stress corrosion cracking (SCC). This study investigated the reversal of sensitization of a naturally exfoliated 5456-H116 alloy plate by planned heating treatment with a short exposure to 250°C. The properties of sensitized …

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Robust Adaptive Motion Control With Environmental Disturbance Rejection For Perturbed Underwater Vehicles, Hamid Reza Koofigar Aug 2014

Robust Adaptive Motion Control With Environmental Disturbance Rejection For Perturbed Underwater Vehicles, Hamid Reza Koofigar

Journal of Marine Science and Technology–Taiwan

This paper addresses the motion control problem of autonomous underwater vehicles (AUVs) perturbed by unknown hydrodynamic coefficients, unmodelled dynamics and environmental disturbances. The proposed algorithm consists of an adaptive subcontroller to tackle the parametric uncertainties and a robust term to vanish the effects of unstructured uncertainties and disturbances. The resulting robust adaptive controller ensures the convergence of tracking error, without any assumption on the upper bound of perturbations in the design procedure. The closed loop stability is shown, using the Lyapunov stability theorem, and verified by various simulations.

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Impact Characteristics Of Free Over-Fall In Pool Zone With Upstream Bed Slope, Shi-I Liu, Jen-Yan Chen, Yao-Ming Hong, Hung-Shin Huang, Rajkumar V Raikar Aug 2014

Impact Characteristics Of Free Over-Fall In Pool Zone With Upstream Bed Slope, Shi-I Liu, Jen-Yan Chen, Yao-Ming Hong, Hung-Shin Huang, Rajkumar V Raikar

Journal of Marine Science and Technology–Taiwan

This paper presents the theoretical equations for the impact characteristics of free over-fall (ICFOF) in the pool zone with sloping upstream bed. The various impact characteristics considered are the brink depth, the impact position and impact angle, the tail water depth and the depth of water pool. In order to overcome the complexity in determining the ICFOF, they were expressed in dimensionless forms as functions of upstream bed slope (UBS), upstream Froude number and Drop number. The multiple regression analysis was used to obtain the empirical expressions for the ICFOF using the laboratory experimental results. It was found that the …

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Effects Of Power System Stabilizer On Inter-Area Oscillations In Vietnam Power System, Van-Dien Doan, Ta-Hsiu Tseng, Pei-Hwa Huang Aug 2014

Effects Of Power System Stabilizer On Inter-Area Oscillations In Vietnam Power System, Van-Dien Doan, Ta-Hsiu Tseng, Pei-Hwa Huang

Journal of Marine Science and Technology–Taiwan

The main objective of this paper is to report a preliminary study of the effects of the power system stabilizer on the small-signal stability and the damping of low-frequency oscillations of the Vietnam power system which is under fast development and has a longitudinal grid pattern. Spontaneous low-frequency oscillations are potential to occur in the exchange of regional power flow of a power system with longitudinal network structure under normal operation. The method of eigen-analysis is utilized to perform the study of the inter-area oscillations with an emphasis on the oscillation mode with low frequency and light damping. The eigenvalues, …

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Contrast Enhancement And Visual Effects Based On Gray-Level Grouping, Yen-Ching Chang, Chun-Ming Chang, Li-Chun Lai, Liang-Hwa Chen Aug 2014

Contrast Enhancement And Visual Effects Based On Gray-Level Grouping, Yen-Ching Chang, Chun-Ming Chang, Li-Chun Lai, Liang-Hwa Chen

Journal of Marine Science and Technology–Taiwan

Contrast enhancement plays a crucial role in the field of image processing. Histogram equalization is a simple and automatic method for contrast enhancement. Conventional contrast-enhancement techniques, such as histogram specification and contrast stretching, require manual parameters to achieve satisfactory results. To automatically produce enhanced results for low-contrast images, a new histogram-based optimized contrast-enhancement technique, called gray-level grouping (GLG), was proposed. GLG performs satisfactorily in dark and low-contrast images and always increases the contrast values to a maximum. Extravagant contrast enhancement typically means sacrificing the visual effects of an image. Through scrutinizing the GLG procedure, we discovered potential limitations and observed …

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An Image Display Device Without A Concrete And Definitive Screen, Junewen Chen, Jing-Bin Duan, Li-An Chiu, Chuan-Sheng Hong, Ya-Ping Kang Aug 2014

An Image Display Device Without A Concrete And Definitive Screen, Junewen Chen, Jing-Bin Duan, Li-An Chiu, Chuan-Sheng Hong, Ya-Ping Kang

Journal of Marine Science and Technology–Taiwan

We present a novel and practical hardwareless display system that was developed for the 3-D projection of real objects in the absence of a concrete screen. In this report, the design and experimental results are presented to demonstrate the display of 360°-viewable objects. Images that are projected on an annular stream of aerosol or fluid can penetrate the layerlike aerosols, thereby displaying a 3-D image. Software can be used to normalize the image data to display life-like images of any model, including customers, and various outfits can be added. Moreover, the images can be visualized in full 360°, and the …

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Three Dimensional Transient Asymmetric Flowfields In Physical Vapor Transport, Joseph Dobmeier Aug 2014

Three Dimensional Transient Asymmetric Flowfields In Physical Vapor Transport, Joseph Dobmeier

Journal of Undergraduate Research at Minnesota State University, Mankato

Physical Vapor Transport is a manufacturing process used to produce single crystals of semiconductor materials such as mercurous chloride (Hg2Cl2). In the past this time-varying process has been studied with numerical simulation by considering three dimensional flow using an axi-symmetric two dimensional model or by restricting the simulation to asymmetric two dimensional flow and dropping the assumption of axi-symmetry from the model. It is generally agreed that neither of these methods accurately represent the true behavior of the process. The purpose of this research was to extend the asymmetric two dimensional model to three dimensions thereby obtaining a solution which …

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Verification Of Costless Merge Pairing Heaps, Joshua Vander Hook Aug 2014

Verification Of Costless Merge Pairing Heaps, Joshua Vander Hook

Journal of Undergraduate Research at Minnesota State University, Mankato

Most algorithms’ performance is limited by the data structures they use. Internal algorithms then decide the performance of the data structure. This cycle continues until fundamental results, verified by analysis and experiment, prevent further improvement. In this paper I examine one specific example of this. The focus of this work is primarily on a new variant of the pairing heap. I will review the new implementation, compare its theoretical performance, and discuss my original contribution: the first preliminary data on its experimental performance. It is instructive to provide some background information, followed by a formal definition of heaps in 1.1. …

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Improvements To Uhmwpe, Brooke Mckelvogue Aug 2014

Improvements To Uhmwpe, Brooke Mckelvogue

Journal of Undergraduate Research at Minnesota State University, Mankato

Ultra high molecular weight polyethylene (UHMWPE) is a material used in artificial implants for articular joint replacements. However, these implants have a limited lifespan in which the patient will be pain-free due to the wear of the UHMWPE components. Recently crosslinking, or exposing the material to radiation, has been used to extend the wear resistance of UHMWPE. Crosslinking introduces another set of drawbacks; mainly the reduction of the fracture toughness of UHMWPE and the generation of free radicals, which leave the polymer vulnerable to damage from oxidation. Currently, research is being conducted on other methods to increase the wear resistance …

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Work In Progress - Peer Directed Learning In A Project Based Model, Andrew Mcnally Aug 2014

Work In Progress - Peer Directed Learning In A Project Based Model, Andrew Mcnally

Journal of Undergraduate Research at Minnesota State University, Mankato

Iron Range Engineering is a new, unique, undergraduate program using problem-based learning. One guiding principle is student responsibility for learning. In order to facilitate learning, faculty and students alike have come up with several learning methods. Learning modes may include self-directed learning, peer-directed learning, one-on-one faculty directed learning, or industry mentored learning. Peer directed learning often manifests in the form of learning groups (a group of students learning similar competencies), led by either a faculty member or a student who has previously excelled in that competency and has taken an interest in pursuing advanced credit. Recently, Iron Range Engineering has …

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Computational Model Of A Left Ventricle: Showing The Effects Of Inertia On Cardiac Dyssynchrony, Andrew Mcnally, Matthew Korpela, Erin Lamke, Matthew Hudson Aug 2014

Computational Model Of A Left Ventricle: Showing The Effects Of Inertia On Cardiac Dyssynchrony, Andrew Mcnally, Matthew Korpela, Erin Lamke, Matthew Hudson

Journal of Undergraduate Research at Minnesota State University, Mankato

In an effort to research heart failure, a leading cause of death in the industrialized world, this research team has developed a segmented lumped parameter model of the left ventricle. The computations model developed focuses on dyssynchrony, a heart condition where some regions of the heart vary significantly in properties like internal muscle resistance, mass, or elastance. Inertial effects are often assumed as negligible by cardiovascular models. One primary function of this model is to investigate inertial effects as they relate to mechanical cardiac dyssynchrony. An added dimension of this analysis is to observe the thermodynamics of the cardiac cycle …

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Optimization Of Reactive Ion Etching (Rie) Parameters For Selective Removal Of Mosfet Gate Dielectric And Evaluation Of Its Physical And Electrical Properties, Hojoon Lee, Samuel Wood Aug 2014

Optimization Of Reactive Ion Etching (Rie) Parameters For Selective Removal Of Mosfet Gate Dielectric And Evaluation Of Its Physical And Electrical Properties, Hojoon Lee, Samuel Wood

Journal of Undergraduate Research at Minnesota State University, Mankato

The integrated circuit (IC) is dominated by technology using Complementary Metal-oxide-Semiconductor Field-effect Transistor (CMOSFET). In order to put over 300 million transistors on silicon chip requires selective removal of material by Reactive Ion Etching (RIE) which ensures vertical cut thereby increasing packing density of devices on the chip. The gate insulator of CMOS devices plays a crucial role in its electrical performance. In this research gate insulator of MOSFET has been etched by state-of-art technique RIE and its physical and electrical properties have been measured. The gate insulator etching by RIE give rise to charge accumulation on the gate dielectric …

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A Cost Benefit Analysis Of Improving Energy Efficiency Of A Fitness Facilty, Inuri A. Illeperuma Aug 2014

A Cost Benefit Analysis Of Improving Energy Efficiency Of A Fitness Facilty, Inuri A. Illeperuma

Journal of Environmental and Resource Economics at Colby

Abstract: Nearly 40% of the total U.S. energy consumption in 2012 was consumed in residential and commercial buildings, as recorded by U.S. Energy Information Administration. With the urgent need to reduce overall energy consumption in the U.S., many efforts are made to improve the energy efficiency of buildings. However, energy managers identify budget constraints as one of the main obstacles in improving the energy efficiency of buildings. Hence this study focuses on a cost benefit analysis of improving the energy efficiency, with a special focus on fitness facilities in college environments. As a case study, the author focuses on improving …

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Pengaruh Berbagai Komposisi Kompos Dalam Tiga Jenis Media Pembibitan Terhadap Pertumbuhan Bibit Asparagus Dalam Polibeg, F. Kholifah, Tino Mutiarawati Onggo, Wawan Sutari Aug 2014

Pengaruh Berbagai Komposisi Kompos Dalam Tiga Jenis Media Pembibitan Terhadap Pertumbuhan Bibit Asparagus Dalam Polibeg, F. Kholifah, Tino Mutiarawati Onggo, Wawan Sutari

Jurnal Kultivasi

Asparagus seeding need suitable medium composition in order that seedlings can grow well and proper to be planted.The experiment aims to study the effect of different seedlings medium and various compost compositions within the medium on growth of asparagus seedlings planted in polybag.The experiment was conducted in research station of Agriculture Faculty, Universitas Padjadjaran, Jatinangor, Sumedang, located at 730 m above the sea level, conducted from May 2013 up to August 2013. A factorial randomized blocks design was used with four replications. The First factor was different seedlings medium, which consisted of three levels: rice husk, rice husk charcoal and …

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Adjustable Resonance Frequency Of Rf-Mems Capacitor By Using Comb- Drive Actuators: A Design Approaches, Agus Santoso Tamsir, Sandy Tannu Wijaya, Dato’ Burhanuddin Yeop Majlis Aug 2014

Adjustable Resonance Frequency Of Rf-Mems Capacitor By Using Comb- Drive Actuators: A Design Approaches, Agus Santoso Tamsir, Sandy Tannu Wijaya, Dato’ Burhanuddin Yeop Majlis

Makara Journal of Technology

The needs of smaller size RF varactor is a must today, and MEMS comes to be the potential one. In this paper we proposed an adjustable resonance RF-MEMS varactor by using comb-drive actuators placing in each side of the square movable plate. In our preliminary simulation, we found that the device can work properly but some constraints comes such as the dominancies of harmonic resonance frequencies that influences into the nominal capacitances. Therefore for the next step of development we have to find out the window of the structural dimension for a certain spans and a certain operating frequencies.

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Make Or Buy Analysis Model Based On Tolerance Design To Minimize Manufacturing Cost And Quality Loss, Cucuk Nur Rosyidi, Reza Rizkichani Akbar, Wakhid Ahmad Jauhari Aug 2014

Make Or Buy Analysis Model Based On Tolerance Design To Minimize Manufacturing Cost And Quality Loss, Cucuk Nur Rosyidi, Reza Rizkichani Akbar, Wakhid Ahmad Jauhari

Makara Journal of Technology

In a manufacturing company, manufacturing costs, or component prices, and tolerance will affect the price and the quality of a product. Companies must produce high-quality products with low manufacturing costs in order to keep their products competitive in the market; however, it is difficult to produce a high-quality product with a low manufacturing cost. Companies have difficulties in determining the components to be produced using their own manufacturing facilities (make) or outsourced to their suppliers (buy). Hence, a make or buy analysis is needed to minimize the manufacturing costs and quality loss and to determine the optimum alternative regarding make …

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Observation Of Tunneling Effects In Lateral Nanowire Pn Junctions, Sri Purwiyanti, Arief Udhiarto, Daniel Moraru, Takeshi Mizuno, Djoko Hartanto, Michiharu Tabe Aug 2014

Observation Of Tunneling Effects In Lateral Nanowire Pn Junctions, Sri Purwiyanti, Arief Udhiarto, Daniel Moraru, Takeshi Mizuno, Djoko Hartanto, Michiharu Tabe

Makara Journal of Technology

As electronic device dimensions are continuously reduced, applied bias conditions significantly change and the transport mechanisms must be reconsidered. Tunneling devices are promising for scaled-down electronics because of expected high-speed operation and relatively low bias. In this work, we investigated the tunneling features in silicon-oninsulator lateral nanowire pn junction and pin junction devices. By controlling the substrate voltage, tunneling features can be observed in the electrical characteristics. We found that the minimum substrate voltage required for tunneling to occur in pn junctions is higher as compared with pin junctions. The main cause of these effects relies in the difference between …

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Argon Ion Irradiation Effect On The Magnetic Properties Of Fe-Al2o3 Nano Granular Film, Setyo Purwanto, Isao Sakamoto Aug 2014

Argon Ion Irradiation Effect On The Magnetic Properties Of Fe-Al2o3 Nano Granular Film, Setyo Purwanto, Isao Sakamoto

Makara Journal of Technology

We studied the effect of Argon (Ar) ion irradiation on Fe-Al2O3 nanogranular thin film. X-ray diffraction (XRD) patterns show that the ion dose might promote the growth of the Fe2O3 phase from an amorphous phase to a crystalline phase. The magnetic and magnetoresistance properties were investigated using a vibrating sample magnetometer (VSM) and a four point probe (FPP). The results suggest that percolation concentration occurred at the 0.55 Fe volume fraction and with a maximum magnetoresistance (MR) ratio of 3%. The present MR ratio was lower than that of previous results, which might be related to the existence of the …

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Digestibility Of Betung Bamboo Fiber Following Fungal Pretreatment, Widya Fatriasari, Wasrin Syafii, Nyoman J. Wistara, Khaswar Syamsu, Bambang Prasetya Aug 2014

Digestibility Of Betung Bamboo Fiber Following Fungal Pretreatment, Widya Fatriasari, Wasrin Syafii, Nyoman J. Wistara, Khaswar Syamsu, Bambang Prasetya

Makara Journal of Technology

This research evaluated the effect of fungal pretreatment of betung bamboo fibers and enzymatic- and microwaveassisted hydrolysis on the reducing sugar yield. The enzymatic hydrolysis of the pretreated biomass was carried out with cellulase and 10 and 20 FPU/g of substrate in a shaking incubator at 50 °C and 150 rpm for 48 h. The sulfuric acid concentration used in the microwave-assisted acid hydrolysis was 1.0, 2.5, and 5%, either with or without the addition of activated carbon. Microwave irradiation (330 Watt) was applied for 5–12.5 min. The yield of reducing sugar was better with the microwave-assisted acid hydrolysis, and …

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