Mechanical Engineering Commons^™

Application Of Fiscal Incentives For Development Of East Natuna Gas Field For Long-Term National Natural Gas Demand, Marwan Batubara, Widodo Wahyu Purwanto, Akhmad Fauzi

Makara Journal of Technology

East Natuna gas field, which has proven reserves of 46 trillion cubic feet, is projected to meet long-term natural gas needs. However, CO2-content of the gas reserves reaches 71%, leading to expensive development costs. This research investigates the feasibility of the field based on several fiscal incentives. Firstly, gas supply-demand until year 2040 was analyzed. Then, based on the analysis, the field was developed using high CO2 gas separation technology to produce gas of 1300 MMSCFD in 2023, 2600 MMSCFD in 2031, and 3900 MMSCFD in 2039. Finally, the economic feasibility was assessed using cash flow analysis in accordance with …

Transmission Electron Microscopy Characterization Of High-Temperatur Oxidation Of Fe-20cr-5al Alloy Prepared By Focused Ion Beam Technique, Mohammad Dani, Pudji Untoro, Teguh Yulius Surya Panca Putra, Parikin Parikin, Joachim Mayer, Arbi Dimyati

Makara Journal of Technology

The Focused Ion Beam (FIB) technique was applied for cross section preparation of the oxidized alloy for Transmission Electron Microscopy (TEM) study. Prior to preparation, the specimens of Fe-20Cr-5Al alloy sheet were oxidized in air at 1200 oC for 2 minutes, 10 minutes, 2 hours, and 100 hours. The microstructure and elemental composition of the samples were characterized using TEM equipped with an Energy Dispersive X-Ray Spectroscopy (EDX). The Electron Energy Loss Spectroscopy (EELS) was used to determine of the light elements. The TEM investigation reveals remarkable microstructure evolution of the specimens during oxidation which generally exhibit a typical multi-layer …

High Temperature Corrosion Of Aluminized Aisi 4130 Steel With The Different Composition Of Nacl/Na2so4 Deposits, Mohammad Badaruddin, Chaur Jeng Wang, Yudhistyra Saputra, Abu Khalid Rivai

Makara Journal of Technology

The high temperature corrosion of AISI 4130 steel can be increased by hot-dip aluminizing coating. The aluminized steel specimens with the deposit composition of 100/0, 30/70, 50/50, 70/30, and 0/100 (wt.%) NaCl/Na2SO4 were oxidized at 750 °C for 1-49 h periods. According to a parabolic rate constant (kp) value, the aluminized steel with deposit composition of 70/30 NaCl/Na2SO4 shows the highest kp value (3.71 × 10-11 g2cm- 4s-1), later followed by the kp value of 3.35 × 10-11 g2cm-4s-1 for 100/0 and the lowest kp value is 7.731 × 10-12 g2cm-4s-1 for 0/100. Whereas, the kp value for the aluminized …

Effects Of Supplier-Manufacturer Relationships On Supply-Chain Performance Of Manufacturing Industries In Indonesia, Rachmad Hidayat, Khisbullah Hudha, Sabarudin Akhmad

Makara Journal of Technology

The present study describes the relationships between commitment, communication, satisfaction, trust, relationship quality with suppliers, and supply-chain performance. The population of the study was manufacturing companies in Indonesia. Respondents were the chief executive officers or corporate secretaries or the designated managers involved in strategic decision making. Samples were taken by using a proportional area random sampling technique. Structural Equation Modeling (SEM) was used for analysis. Results of both direct and indirect testing of hypothesis indicated two hypotheses of positive and significant effects and nine hypotheses of positive but insignificant effects. Those hypotheses of positive and significant effects were the direct …

A New Method For Simulating Power Flow Density Focused By A Silicon Lens Antenna Irradiated With Linearly Polarized Thz Wave, Catur Apriono, Eko Tjipto Rahardjo, Norihisa Hiromoto

Makara Journal of Technology

A terahertz system uses dielectric lens antennas for focusing and collimating beams of terahertz wave radiation. Linearly polarized terahertz wave radiation has been widely applied in the terahertz system. Therefore, an accurate method for analyzing the power flow density in the dielectric lens antenna irradiated with the linearly polarized terahertz wave radiation is important to design the terahertz systems. In optics, ray-tracing method has been used to calculate the power flow density by a number density of rays. In this study, we propose a method of ray-tracing combined with Fresnel’s transmission, including transmittance and polarization of the terahertz wave radiation …

Stochastic Optimization Of Supply Chain Risk Measures –A Methodology For Improving Supply Security Of Subsidized Fuel Oil In Indonesia, Adinda Yuanita, Andi Noorsaman Sommeng, Anondho Wijonarko

Makara Journal of Technology

Monte Carlo simulation-based methods for stochastic optimization of risk measures is required to solve complex problems in supply security of subsidized fuel oil in Indonesia. In order to overcome constraints in distribution of subsidized fuel in Indonesia, which has the fourth largest population in the world—more than 250,000,000 people with 66.5% of productive population, and has more than 17,000 islands with its population centered around the nation's capital only—it is necessary to have a measurable and integrated risk analysis with monitoring system for the purpose of supply security of subsidized fuel. In consideration of this complex issue, uncertainty and probability …

Thermodynamic Analysis Of Irreversible Heat-Transformers, Niccolo` Giannetti, Arnas Arnas, Andrea Rocchetti, Kiyoshi Saito

Makara Journal of Technology

Absorption heat transformers extend the possibilities for efficient and environment-friendly energy conversion processes. Based on a general thermodynamic model of three-thermal cycles with finite thermal capacity of the heat sources, this paper is intent upon analyzing and optimizing the performance of absorption heat transformers, by including the influence of irreversibility in the analytical expression of the system efficiency. Dimensionless parameters for an overall optimization are defined and a first screening is performed to clarify their influence. Dependence on the main factors is highlighted to suggest how to change them in order to enhance the whole system performance. Under this point …

Design And Fabrication Of Liquid Scintillator Counter, Andrea Calderon Saucedo, John L. Orrell

STAR Program Research Presentations

Pacific Northwest National Laboratory (PNNL) is currently developing an ultra-low background liquid scintillator counter (ULB LSC) in the shallow underground laboratory. At a depth of 35-meters water-equivalent, the underground laboratory has a multi-layered shielding to keep out cosmic-ray induced background. The ULB LSC, which is located in a clean room facility, is a multi-layered design made up of various materials, including plastic scintillator veto panels, borated polyethylene, lead and copper. These layers help lower the contributions of the terrestrial background and intrinsic background, resulting from the impurities present in the materials, to the overall background count rate observed by the …

Effect Of Respiration On Cardiac Filling At Rest And During Exercise In Fontan Patients: A Clinical And Computational Modeling Study, Alexander Van De Bruaene, Guido Claessen, Andre La Gerche, Ethan Kung, Alison Marsden, Pieter De Meester, Sarah Devroe, Jan Bogaert, Piet Claus, Hein Heidbuchel, Werner Budts, Marc Gewillig

Publications

Due to the absence of a sub-pulmonary ventricle, the Fontan circulation is sensitive to respiration-induced changes in intrathoracic pressure. However, the importance of a ‘respiratory pump’ in creating forward flow remains controversial. We aimed at evaluating the effect of respiration on ventricular filling during exercise using clinical data and computational modeling predictions. Ten Fontan patients (6 male, 20 ± 4 years) underwent ungated cardiac magnetic resonance (CMR) imaging at rest and during supine bicycle exercise to evaluate systemic ventricular volumes (end-diastolic volume index (EDVi), end-systolic volume index (ESVi) and stroke volume index (SVi)) during normal respiration and a Valsalva maneuver. …

Wind Tunnel Flow Characterization Utilizing Turbulence Spheres, David Omar Cano

Theses and Dissertations - UTB/UTPA

When it comes to designing products that will be highly subjected to the aerodynamics of the atmospheric freestream, it’s vital to take into consideration parameters such as geometry and surface smoothness. The optimization of the performance of certain products may be done so with the usage of wind tunnel testing. In order to utilize this tool to its full potential, the flow quality must be pre-determined before running tests. In determining the flow quality there are two main parameters needed to obtain this value. These parameters are referred to as the Turbulence Factor (TF) and Turbulence Intensity (TI). To calculate …

Two Dimensional Inverse Dynamics Model Of Human Knee Dynamics During The Moderate Squat Exercise, Ricardo Gomez Jr.

Theses and Dissertations - UTB/UTPA

The purpose of this research is to investigate the internal forces on the human knee joint during moderate squat exercise. An inverse dynamics, two dimensional, anatomic dynamic knee model is developed. The model describes the motion in the sagittal plane of human leg, and includes tibia, femur, ligamentous knee structures, tendons and muscles. The software package Matlab is used to solve the inverse dynamics model. Numerical simulations are conducted for walking (the stance phase of the gait cycle) in order to validate the model, and for moderate squatting in order to predict ligament, contact and muscle forces during this exercise.

Development Of Metallic And Ceramic Nanotubes Via Magnetron Sputtering, Hillario Cortez

Theses and Dissertations - UTB/UTPA

Nanotechnology has been extensively studied throughout the years and has allowed for the development of new structures and technologies. Nanofibers in particular have intrinsically unique properties such as large surface area to volume ratio. Nanofiber structures have a wide range of applications that include: catalysts, sensors, biomedical scaffolds, filtration devices, high performance textiles, energy storage systems, sensitized solar cells, photonics, nanocomposites, membranes, drug delivery systems, and electronics. The objective of this work is to fabricate nanotubular structures by employing the template approach. The template approach consists in the fabrication of circular shaped templates, nanofibers, and then coating the template fibers …

Non-Intrusive Second Law Performance Evaluation Of A Domestic Freezer, Jim Mcgovern, S. Oladunjoye

Conference Papers

This paper describes non-intrusive performance testing and second law, exergy-based, performance evaluation of a small, contemporary domestic freezer that used R600a refrigerant. The methodology presented is associated with logging of temperatures and the instantaneous power consumption. It gives a ‘second law of thermodynamics’ perspective on operating performance by providing rational efficiency values and by localizing and quantifying the instantaneous exergy destruction rates. This approach is compared to a more conventional ‘first law’ energy analysis. Suggestions are made for the standardization of such an approach in order to enhance the sustainability of domestic freezers. Keywords: Domestic freezer, Performance testing, Performance evaluation, …

The Search For High-Impact Diagnostic And Management Tools For Low-And Middle-Income Countries: A Self-Powered Low-Cost Blood Pressure Measurement Device Powered By A Solid-State Vibration Energy Harvester, Onur Bilgen, John G. Kenerson, Muge Akpinar-Elci, Rebecca Hattery, Lisbet M. Hanson

Mechanical & Aerospace Engineering Faculty Publications

The World Health Organization has established recommendations for blood pressure measurement devices for use in low-resource venues, setting the triple A expectations of Accuracy, Affordability, and Availability. Because of issues related to training and assessment of proficiency, the pendulum has swung away from manual blood pressure devices and auscultatory techniques towards automatic oscillometric devices. As a result of power challenges in the developing world, there has also been a push towards semiautomatic devices that are not dependent on external power sources or batteries. Beyond solar solutions, disruptive technology related to solid-state vibrational energy harvesting may be the next iterative solution …

Reactive Motions In A Fully Autonomous Crs Catalyst 5 Robotic Arm Based On Rgbd Data, Arad Haselirad

Theses and Dissertations

This study proposes a method to perform velocity estimation using motion blur in a single image frame along x and y axes in the camera coordinate system and intercept a moving object with a robotic arm. It will be shown that velocity estimation in a single image frame improves the system's performance. The majority of previous studies in this area require at least two image frames to measure the target's velocity. In addition, they mostly employ specialized equipments which are able to generate high torques and accelerations.

The setup consists of a 5 degree of freedom robotic arm and a …

Random Actuation Pattern Optimization By Genetic Algorithm For Ultrasonic Structural Health Monitoring Of Plates, Pierrot R. Derjany

Doctoral Dissertations and Master's Theses

The objective of this research is to investigate an optimized two-dimensional random pattern of uniformly excited points using the Genetic Algorithm (GA) technique for structural health monitoring. The point excitations generate ultrasonic waves in both isotropic and anisotropic materials that can be effective in diagnosing structural defects. The formed ultrasonic waves can constructively interfere and send out an intense wave beam to a predetermined target. The constructed wave beams can be steered to different directions with variable target distances. In the GA, the cost function is constructed to reduce main lobe beamwidth, eliminate grating lobes and suppress sidelobes’ levels. Mathematical …

Three-Dimensional Scaffolds Of Graphene, Carbon Nanotubes And Transition-Metal Oxides For Applications In Electronics, Sensors And Energy Storage, Gilbert N. Mbah

Department of Chemistry: Dissertations, Theses, and Student Research

Electronics, sensors and energy storage devices are the new waves behind economic development, security and communication¹. Engineering small sizes of electronic, sensors and energy storage devices is the hurdle limiting efficient, portable and vast applications of Nano-devices for economic, security and communication advancement². Silicon the major material used in transistors has approached its limit to fabricated Nano-devices³. The discovery of free standing, one atomic layer thick and two-dimensional graphene sheets with high conductivity, inert, high specific surface area, stable and high tensile strength material in 2004 has shown capabilities to replaced silicon in electronics, …

On The Selection Of A Good Shape Parameter For Rbf Approximation And Its Application For Solving Pdes, Lei-Hsin Kuo

Dissertations

Meshless methods utilizing Radial Basis Functions~(RBFs) are a numerical method that require no mesh connections within the computational domain. They are useful for solving numerous real-world engineering problems. Over the past decades, after the 1970s, several RBFs have been developed and successfully applied to recover unknown functions and to solve Partial Differential Equations (PDEs).
However, some RBFs, such as Multiquadratic (MQ), Gaussian (GA), and Matern functions, contain a free variable, the shape parameter, c. Because c exerts a strong influence on the accuracy of numerical solutions, much effort has been devoted to developing methods for determining shape parameters which provide …

Neutral Parametric Canonical Form For 2d And 3d Wireframe Cad Geometry, Robert Steven Freeman

Theses and Dissertations

The challenge of interoperability is to retain model integrity when different software applications exchange and interpret model data. Transferring CAD data between heterogeneous CAD systems is a challenge because of differences in feature representation. A study by the National Institute for Standards and Technology (NIST) performed in 1999 made a conservative estimate that inadequate interoperability in the automotive industry costs them $1 billion per year. One critical part of eliminating the high costs due to poor interoperability is a neutral format between heterogeneous CAD systems. An effective neutral CAD format should include a current-state data store, be associative, include the …

Improving The Suction Performance And Stability Of An Inducer With An Integrated Inlet Cover Bleed System Known As A Stability Control Device, Ryan K. Lundgreen

Theses and Dissertations

The performance of an inducer with the integration of an inlet cover bleed system known as a stability control device (SCD) is investigated using computational fluid dynamics. Inducers are the first stage of high suction performance pumps and are designed to operate under cavitating conditions. Improvements in design have allowed inducers to operate stably with low inlet head conditions, however, cavitation instabilities ultimately lead to pump failure. It has been shown that inducers that employ an SCD fully suppress cavitation instabilities.The performance of an inducer is explored at both on- and off-design flow coefficients, where the flow coefficient is a …

Jet And Droplet Impingement On Superhydrophobic Surfaces, Jonathan Glenn Stoddard

Theses and Dissertations

The effect of superhydrophobicity on liquid water impingement on a flat horizontal surface was explored. The surfaces combined a hydrophobic surface chemistry with a patterned microstucture in order to produce high contact angles with water. Three sets of experiments were performed, one for jet impingement and two for droplet impingement, which advance previous work in characterizing the interaction of water and superhydrophobic surfaces.Jet impingement experiments were performed to characterize a transitional regime between an unsubmerged and a completely submerged superhydrophobic surface by varying an imposed downstream depth. For low downstream depths, the surface remained unsubmerged and displayed only break up …

An Estimate Of The Second-Order In-Plane Acceleration Sensitivity Of A Y-Cut Quartz Thickness-Shear Resonator, Huijing He, Jiashi Yang, John A. Kosinski

Department of Mechanical and Materials Engineering: Faculty Publications

We perform a theoretical analysis of the second-order in-plane acceleration sensitivity of a Y-cut quartz thick-ness-shear mode resonator. The second-order nonlinear theory of elasticity for anisotropic crystals is used to determine the biasing fields in the resonator under in-plane acceleration. The acceleration-induced frequency shift is determined from a per-turbation analysis based on the plate equations for small-amplitude vibrations superposed on a finite bias. We show that, whereas the first-order acceleration-induced frequency shift is zero for a structurally symmetric resonator under in-plane ac-celeration, the second-order frequency shift is nonzero and is quadratic in the acceleration. As the fourth-order nonlinear elastic constants …

Two-Dimensional Dynamics Model Of The Lower Limb To Include Viscoelastic Knee Ligaments, Eduardo Granados

Theses and Dissertations - UTB/UTPA

A dynamic, 2D, anatomical knee joint model has been developed to simulate knee reactions to external input forces. A deformable contact area approach is used to find contact forces and moments, and a method of applying nonlinear viscoelastic ligament strain rate response was also developed and implemented on the model to account for the effects of viscoelasticity on the ligament fibers. The ligaments were then tested for various deficiencies to identify their effects on the natural frequency of the knee. Internal knee forces from ligaments, muscles, and contacting surfaces are modeled and then numerically found for different exercises. Static and …

Development, Optimization, And Implementation Of A Vibration Based Defect Detection Algorithm For Railroad Bearings, Amy Gonzalez

Theses and Dissertations - UTB/UTPA

Of the three main rail accident types in the United States, derailments are the most common. Studies have shown that derailments occurring above 25 mph are caused by equipment failures such as bearing failures. As a preventative measure, condition-monitoring systems are required to detect defective bearings in the field. Based on data compiled from multiple experiments of healthy and defective bearings at UTPA, an algorithm has been devised to identify bearing abnormalities. Vibration analysis techniques are utilized to potentially determine whether a bearing is defective and the defect type and size using the acquired vibration signatures. Implementation of a defect …

Onboard Load Sensor Prototype For Use In Freight Railcar Service, Thomas Michael Diedrich

Theses and Dissertations - UTB/UTPA

Determining the exact load carried by an individual railcar is crucial in the railroad industry. With an accurate load measurement, the filling process can be optimized to provide maximum cargo load without exceeding the loading thresholds set by the Association of American Railroads (AAR). In addition to optimizing the cargo load, an accurate load measurement will make it possible to identify any load imbalance in the railcar which has detrimental effects on bearing. Previous work conducted with a strain-gauge-based load sensor suspended between a thermoplastic steering pad and a bearing adapter provided accurate load data in the laboratory setting. This …

Nonlinear Dynamics Of Electrostatically Actuated M/Nems Plates To Include Casimir And Van Der Waals Effects, Reynaldo Oyervides

Theses and Dissertations - UTB/UTPA

The amplitude-frequency response and voltage-amplitude response of electrostatically actuated micro and nano-electromechanical systems (M/NEMS) clamped circular plates are investigated. The system is actuated by soft AC voltage at frequency near half natural frequency of the plate, and another case near natural frequency of the plate, they resulting in primary and parametric resonances of the system, respectively. The system is first analytically modeled using the Method of Multiple Scales (MMS). MMS results are then compared to Reduced Order Model (ROM) method frequency response numerical simulations. Besides MMS and ROM, time response simulations are conducted. The agreement of the frequency responses of …

Natural Polymer Based Composite Scaffolds For Tissue Engineering Applications, Marcos R. Villarreal

Theses and Dissertations - UTB/UTPA

The fabrication, characterization, and bio-assessment of two types of perspective tissue engineering (TE) scaffolds are presented. Principally derived of biopolymers, both types of scaffolds generally followed porous scaffold methodologies for synthesis. Differentiating the two scaffold varieties was chiefly driven by crosslinking attainment, where crosslinking is argued to add structural stability and aid in regulating biodegradability rates in TE scaffolds. Microwave irradiation via conventional microwave was one method used to prospectively crosslink cornstarch to chitosan and sodium alginate. Triethyl orthoformate, was used to prospectively crosslink collagen and chitosan. After the scaffolds were “crosslinked” they were subjected to freeze drying techniques in …

Feasibility Study Of Custom Manufacturing Of Ionic Polymer-Metal Composite Sensors, Shelby E. Nelson

UNLV Theses, Dissertations, Professional Papers, and Capstones

The ability to create an ion exchange membrane with any shape or thickness through custom manufacturing techniques is highly desirable in ionic polymer-metal composite (IPMC) research. This is caused by the poor selection and limited availability of certain thicknesses of commercial ion exchange membranes. The objective of this study is to determine the feasibility of manufacturing custom ion exchange membranes for IPMC sensors. The manufacturing methods used in this study are extrusion, injection molding, and hot pressing. A commercial membrane from Golden Energy Fuel Cells (GEFC) is used as a comparison. After the membranes are fabricated, certain properties of the …

Cfd Simulation Of Heat Enhancement In Internally Helical Grooved Tubes, Sogol Pirbastami

UNLV Theses, Dissertations, Professional Papers, and Capstones

Heat exchanger devices are widely used in industries, air conditioning systems, refrigeration, etc. These devices have a major role in energy conservation; therefore, increasing the performance of heat exchangers helps save energy, costs and materials. The technique to increase the heat transfer performance is called heat augmentation, which can be applied to pipe surfaces and other surfaces which are used in heat exchangers to improve thermal performance. These techniques are categorized into 3 groups: passive, active and compound technique. In this study a helically machined rectangular groove on the inside of a 2.0 m tube with a diameter of 7.1mm …

Performance Analysis Of A Copper Ii Sulfate Pentahydrate Based Thermogalvanic Cell., Steffen Krebs

Electronic Theses and Dissertations

Low grade heat recovery systems are more relevant today due to the rising costs in energy and transition to non-fossil fuel energy sources. Thermogalvanic cells show potential due to low cost and scalability. In this study the performance of a Copper II Sulfate Pentahydrate based electrolyte was evaluated. The effects of electrolyte concentration, electrode separation, and electrode surface area were studied experimentally. Conductive heat transfer within the electrolyte was simulated via SolidWorks. All experimental thermocell testing was conducted to find the maximum power production of a particular cell design. The base cell had a six inch electrode separation with two …