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Articles 781 - 810 of 957

Full-Text Articles in Mechanical Engineering

Augmented Reality Navigation Interfaces Improve Human Performance In End-Effector Controlled Telerobotics, Keshav Chintamani Jan 2010

Augmented Reality Navigation Interfaces Improve Human Performance In End-Effector Controlled Telerobotics, Keshav Chintamani

Wayne State University Dissertations

On the International Space Station (ISS) and space shuttles, the National Aeronautics and Space Administration (NASA) has used robotic manipulators extensively to perform payload handling and maintenance tasks. Teleoperating robots require expert skills and optimal performance is crucial to mission completion and crew safety. Degradation in performance is observed when manual control is mediated through remote camera views, resulting in poor end-effector navigation quality and extended task completion times. This thesis explores the application of three-dimensional augmented reality (AR) interfaces specifically designed to improve human performance during end-effector controlled teleoperations. A modular telerobotic test bed was developed for this purpose …

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Semi-Automatic Image Segmentation For Volumetric Visualization Of Pelvis Ct Scan-Images, Suprijanto Suprijanto, Farida I. Muchtadi, Irwan Setiawan Nov 2009

Semi-Automatic Image Segmentation For Volumetric Visualization Of Pelvis Ct Scan-Images, Suprijanto Suprijanto, Farida I. Muchtadi, Irwan Setiawan

Makara Journal of Technology

Semi-Automatic Image Segmentation for Volumetric Visualization of Pelvis CT Scan-Images. The current development of computerized tomography (CT) has enable us to obtain cross sectional image using multi slicing techniques in an order of few seconds. The obtained images represent several tissue structures on cross section slice being imaged. One challenge to help diagnosis using CT images is extracting an anatomic structure of interest using a method of image segmentation and volumetric visualization with the assistance of computers. In case of volumetric visualization of pelvis bones extracted from multi-slice CT images, whole images which are containing part of pelvis bone structures …

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Implementation Of Six Sigma Method To Maintain The Quality Of Construction Projects, Yusuf Latief, Retyaning Puji Utami Nov 2009

Implementation Of Six Sigma Method To Maintain The Quality Of Construction Projects, Yusuf Latief, Retyaning Puji Utami

Makara Journal of Technology

Implementation of Six Sigma Method to Maintain The Quality of Construction Projects. Six sigma (6-sigma) is a method that widely developed in the world, especially in manufacturing industry to decrease failures in achieving good quality in construction projects. The objective of this research is to explore the existing condition of quality management and the aplication of 6-sigma method in maintaining quality of construction projects. Structured interviews to experienced experts and people who were recommended by their companies were conducted. Non-parametric analysis using frequencies distribution procedures were used for analysis. The result shows that existing condition in quality management of construction …

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Mechanical Properties Of Ramie Fiber Reinforced Epoxy Lamina Composite For Socket Prosthesis, Tresna P. Soemardi, Widjajalaksmi Kusumaningsih, Agustinus Purna Irawan Nov 2009

Mechanical Properties Of Ramie Fiber Reinforced Epoxy Lamina Composite For Socket Prosthesis, Tresna P. Soemardi, Widjajalaksmi Kusumaningsih, Agustinus Purna Irawan

Makara Journal of Technology

Mechanical properties of ramie fiber reinforced epoxy lamina composite for socket prosthesis. This paper presents an investigation into the application of natural fiber composite especially ramie fiber reinforced epoxy lamina composite for socket prosthesis. The research focuses on the tensile and shear strength from ramie fiber reinforced epoxy lamina composite which will be applied as alternative material for socket prosthesis. The research based on American Society for Testing Material (ASTM) standard D 3039/D 3039M for tensile strength and ASTM D 4255/D 4255M-83 for shear strength. The ramie fiber applied is a fiber continue 100 % Ne14'S with Epoxy Resin Bakelite …

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Potency Of Thermoelectric Generator For Hybrid Vehicle, Nandy Putra, Raldi Artono Koestoer, Mohammad Adhitya, Ardian Roekettino, Bayu Trianto Nov 2009

Potency Of Thermoelectric Generator For Hybrid Vehicle, Nandy Putra, Raldi Artono Koestoer, Mohammad Adhitya, Ardian Roekettino, Bayu Trianto

Makara Journal of Technology

Potency of Thermoelectric Generator for Hybrid Vehicle. Thermoelectric Generator (TEG) has been known as electricity generation for many years. If the temperature difference occurred between two difference semi conductor materials, the current will flow in the material and produced difference voltage. This principle is known as Seebeck effect that is the opposite of Peltier effect Thermoelectric Cooling (TEC). This research was conducted to test the potential of electric source from twelve peltier modules. Then, these thermoelectric generators were applied in hybrid car by using waste heat from the combustion engine. The experiment has been conducted with variations of peltier module …

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Effects Of Ph On Calcium Carbonate Precipitation Under Magnetic Field, Nelson Saksono, Yuliusman Yuliusman, Setijo Bismo, Roekmijati W. Soemantojo, Azwar Manaf Nov 2009

Effects Of Ph On Calcium Carbonate Precipitation Under Magnetic Field, Nelson Saksono, Yuliusman Yuliusman, Setijo Bismo, Roekmijati W. Soemantojo, Azwar Manaf

Makara Journal of Technology

Magnetic field effect on CaCO3 precipitation is the key parameter in evaluating the effectiveness of Anti-scale Magnetic Treatment (AMT). The purpose of this study was to investigate magnetic fields influence on CaCO3 precipitation in high and low super-saturated CaCO3 solution by varied pH CaCO3 solution using circulation flow fluid system. The observation results in the high super saturated solution (pH 8.5) showed the increase of precipited CaCO3 in magnetized solutions compared to those in non-magnetic solution during circulation process. In the low super-saturated CaCO3 solution (pH 6.4) it was found that magnetic treatment increased CaCO3 precipitation after circulation process. In …

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Performance Of Hollow Fiber Membrane Gas-Liquid Contactors To Absorb Co2 Using Diethanolamine (Dea) As A Solvent, Sutrasno Kartohardjono, Pan Ade Nata, Eko Prasetio, Yuliusman Yuliusman Nov 2009

Performance Of Hollow Fiber Membrane Gas-Liquid Contactors To Absorb Co2 Using Diethanolamine (Dea) As A Solvent, Sutrasno Kartohardjono, Pan Ade Nata, Eko Prasetio, Yuliusman Yuliusman

Makara Journal of Technology

This study uses DEA solution to absorb CO2 from the gas flow through the hollow fiber membrane contactors. This study aims to evaluate the performance of hollow fiber membrane contactors to absorb CO2 gas using DEA solution as solvent through mass transfer and hydrodynamics studies. The use of DEA solution is to reduce the mass transfer resistance in the liquid phase, and on the other side, the large contact area of the membrane surface can cover the disadvantage of membrane contactors; additional mass transfer resistance in the membrane phase. During experiments, CO2 feed flows through the fiber lumens, while the …

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Intermetallic Cu3sn Phase Layer On Electrode’S Tip Of Galvanized Resistance Spot Welding, Muhammad Anis, Aulia Irsyadi, Deni Ferdian Nov 2009

Intermetallic Cu3sn Phase Layer On Electrode’S Tip Of Galvanized Resistance Spot Welding, Muhammad Anis, Aulia Irsyadi, Deni Ferdian

Makara Journal of Technology

Intermetallic Cu3Sn Phase Layer on Electrode’s Tip of Galvanized Resistance Spot Welding. A resistance spot welding method is commonly used in automotive industries application. In a resistance spot welding method, the copper electrode has a significant role as an electric current carrier for joining thin metal sheet. This research was focused on studying the effect of tin layer at the electrode tip for joining galvanized steel sheet. The main variable of this research is in the thickness of the intermetallic Cu3Sn layer. The result showed that the introduction of tin layer less than 1 μm in thickness on the electrode …

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Simple Ml Detector For Multiple Antennas Communication System, Ahmad Taqwa, Soegijardjo Soegijoko, Sugihartono Sugihartono, Suhartono Tjondronegoro Nov 2009

Simple Ml Detector For Multiple Antennas Communication System, Ahmad Taqwa, Soegijardjo Soegijoko, Sugihartono Sugihartono, Suhartono Tjondronegoro

Makara Journal of Technology

Simple ML Detector for Multiple Antennas Communication System. In order to support providing broadband wireless communication services against limited and expensive frequency bandwidth, we have to develop a bandwidth efficient system. Therefore, in this paper we propose a closed-loop MIMO (Multiple-Input-Multiple-Output) system using ML (Maximum Likelihood) detector to optimize capacity and to increase system performance. What is especially exciting about the benefits offered by MIMO is that a high capacity and performance can be attained without additional frequency-spectral resource. The grand scenario of this concept is the attained advantages of transformation matrices having capability to allocate transmitted signals power suit …

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Towards Supervised Autonomous Task Completion Using An In Vivo Surgical Robot, Jason J. Dumpert Oct 2009

Towards Supervised Autonomous Task Completion Using An In Vivo Surgical Robot, Jason J. Dumpert

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Laparoscopy is a minimally invasive alternative to traditional abdominal surgery. Unlike traditional surgery, a laparoscopic procedure can be completed using small incisions. The use of these small incision results in reduced pain to the patient, shorter recovery times, and less trauma to skin, muscle and other tissues. However, these benefits to the patient are offset by the increased difficulty to the surgeon performing the procedure. These difficulties include reduced dexterity, reduced perception, and longer procedure times. The use of small in vivo robotic devices in minimally invasive surgery is one possible solution to these problems. The movement of these devices …

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Development Of A New Lagrangian Float For Studying Coastal Marine Ecosystems, Alex Schwithal, Chris Roman May 2009

Development Of A New Lagrangian Float For Studying Coastal Marine Ecosystems, Alex Schwithal, Chris Roman

Graduate School of Oceanography Faculty Publications

This paper presents an overview and initial testing results for a shallow water Lagrangian float designed to operate in coastal settings. The presented effort addresses the two main characteristics of the shallow coastal environment that preclude the direct of use of many successfully deep water floats, namely the higher variation of water densities near the coast compared with the open ocean and the highly varied bathymetry. Our idea is to develop a high capacity dynamic auto-ballasting system that is able to compensate for the expected seawater density variation over a broad range of water temperatures and salinities while using measurements …

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2009 (Spring) Ensi Informer Magazine, Morehead State University. Engineering Sciences Department Apr 2009

2009 (Spring) Ensi Informer Magazine, Morehead State University. Engineering Sciences Department

ENSI Informer Magazine Archive

The ENSI Informer Magazine published in the spring of 2009.

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Improved Predictive Power Control Of Cdma System In Rayleigh Fading Channel, Adit Kurniawan, Iskandar Iskandar, Sayid Machdar Apr 2009

Improved Predictive Power Control Of Cdma System In Rayleigh Fading Channel, Adit Kurniawan, Iskandar Iskandar, Sayid Machdar

Makara Journal of Technology

In this paper an improved prediction-based power control is proposed for code division multiple access (CDMA) systems in Rayleigh fading channel environments. One of the most serious problems which degrades the performance of power control algorithm is the effect of feedback delay. To overcome the effect of feedback delay, power control needs to employ prediction algorithm which utilises the correlation property of the past channel samples measurements to predict the future sample values. In CDMA power control, however, the correlation property of channel measurements is destroyed because the transmit power is continuously updated for each power control interval. The prediction …

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On The Performance Of Svd-Dwt Based Digital Video Watermarking Technique With Semi-Blind Detector, Tarzan Basaruddin, Della Maulidiya Apr 2009

On The Performance Of Svd-Dwt Based Digital Video Watermarking Technique With Semi-Blind Detector, Tarzan Basaruddin, Della Maulidiya

Makara Journal of Technology

On the Performance of SVD-DWT Based Digital Video Watermarking Technique with Semi-Blind Detector. This paper presents a watermarking technique for digital video. The proposed scheme is developed based on the work of Ganic and Chan which took the virtue of SVD and DWT. While the previous works of Chan has the blind detector property, our attempt is to develop a scheme with semi-blind detector, by using the merit of the DWT-SDV technique proposed by Ganic which was originally applied to still image. Overall, our experimental results show that our proposed scheme has a very good imperceptibility and is reasonably robust …

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Lipid Production From Microalgae As A Promising Candidate For Biodiesel Production, Arief Widjaja Apr 2009

Lipid Production From Microalgae As A Promising Candidate For Biodiesel Production, Arief Widjaja

Makara Journal of Technology

Recently, several strains of microalgae have been studied as they contain high lipid content capable to be converted to biodiesel. Fresh water microalgae Chlorella vulgaris studied in this research was one of the proof as it contained high triacyl glyceride which made it a potential candidate for biodiesel production. Factors responsible for good growing of microalgae such as CO2 and nitrogen concentration were investigated. It was found that total lipid content was increased after exposing to media with not enough nitrogen concentration. However, under this nitrogen depletion media, the growth rate was very slow leading to lower lipid productivity. The …

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Environmental Remediation Full-Scale Implementation: Back To Simple Microbial Massive Culture Approaches, Agung Dhamar Syakti, Mohamad Yani Apr 2009

Environmental Remediation Full-Scale Implementation: Back To Simple Microbial Massive Culture Approaches, Agung Dhamar Syakti, Mohamad Yani

Makara Journal of Technology

Using bioaugmentation and biostimulation approach for contaminated soil bioremediation were investigated and implemented on field scale. We combine those approaches by culturing massively the petrophilic indigenous microorganisms from chronically contaminated soil enriched by mixed manure. Through these methods, bioremediation performance revealed promising results in removing the petroleum hydrocarbons comparatively using metabolite by product such as biosurfactant, specific enzymes and other extra-cellular product which are considered as a difficult task and will impact on cost increase.

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Preparation Of Radioactive Gold Nanoparticle By Neutron Activation, Rohadi Awaludin Apr 2009

Preparation Of Radioactive Gold Nanoparticle By Neutron Activation, Rohadi Awaludin

Makara Journal of Technology

Preparation of Radioactive Gold Nanoparticle by Neutron Activation. It was reported that gold nanoparticle could be used for cancer therapy using thermal effect. It is possible to kill cancer cells using radiation of radioisotope. Study on preparation of radioactive gold by neutron activation at central irradiation position (CIP) of G.A. Siwabessy reactor with neutron flux 1.26 x 1014 neutron s-1cm-2 has been carried out. It was revealed that a radioisotop of gold (198Au) was produced by neutron activation from natural gold. Calculation results showed that 198Au with radioactivity of 0.366 Bq, 2.93 Bq, 9.90 Bq and 23.4 Bq was produced …

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Implementation Of Web Cam As Motion Detector With Directshow Interfacing, Yonatan Santoso, Iwan Setiyawan, Victor N. Papilaya Apr 2009

Implementation Of Web Cam As Motion Detector With Directshow Interfacing, Yonatan Santoso, Iwan Setiyawan, Victor N. Papilaya

Makara Journal of Technology

Implementation of Web Cam as Motion Detector with DirectShow Interfacing. One of many ways to take control a web cam is by using DirectShow which is integrated in DirectX. DirectShow acts like an API therefore it is easier to use. Afterwards, web cam will be implemented to detect object’s motion as well as camera surveillance. The method is by comparing a reference image with other image which is taken lately. If there are differences between those image it means motion has been detected.

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Thermal Stability Of Clay's Galleries In Polypropylene - Clay (Montmorillonite) Nanocomposites Using Polypropylene-Gmaleic Anhydride As Compatibilizer, Sotya Astutiningsih, Pandu Lanang Kinasih, Arief Cahyo Wibowo Apr 2009

Thermal Stability Of Clay's Galleries In Polypropylene - Clay (Montmorillonite) Nanocomposites Using Polypropylene-Gmaleic Anhydride As Compatibilizer, Sotya Astutiningsih, Pandu Lanang Kinasih, Arief Cahyo Wibowo

Makara Journal of Technology

Thermal Stability of Clay's Galleries in Polypropylene - Clay (montmorillonite) Nanocomposites using Polypropylene-g- Maleic Anhydride as Compatibilizer. Superior properties of food packaging can be achieved using nanocomposite technology. However, fabrication of this materials are complex and expensive. Long term objectives of this research is the synthesis of low cost polypropylene clay nanocomposites (PPCN) via a short-cut method known as ‘cascade engineering’. Cascade engineering principle in PPCN fabrication is performed by using compatibilizer (to enable the mixing of PP and clay) masterbatch, and PPCN in one pot process using melt mixer. This paper present the experimental results using small-angle x-ray diffraction …

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Induction And Conduction Electromagnetic Waves Caused By Lightning Strike On The Low Voltage Network, Reynaldo Zoro Apr 2009

Induction And Conduction Electromagnetic Waves Caused By Lightning Strike On The Low Voltage Network, Reynaldo Zoro

Makara Journal of Technology

Induction and Conduction Electromagnetic Waves Caused by Lightning Strike on the Low Voltage Network. Direct and indirect lightning strikes can disturb and induce low voltage overheadlines and it can produced overvoltage due to traveling waves along the lines. This overvoltage can damage the equipments connected to it. It was recorded that there were already a lot of damages of electronic equipments and arrestesr located inside the building of Lightning Measurement Station at Mnt. Tangkuban Perahu. Most of the overvoltage which was developed on the low voltage lines were coming from indirect lightning strike nearby due to the fact that most …

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Muara Bekasi – Muara Tawar Offshore Transmission Pipeline Routing And Economic Analysis., Asep Handaya Saputra, Ardiansyah Ardiansyah Apr 2009

Muara Bekasi – Muara Tawar Offshore Transmission Pipeline Routing And Economic Analysis., Asep Handaya Saputra, Ardiansyah Ardiansyah

Makara Journal of Technology

Muara Bekasi – Muara Tawar Offshore Transmission Pipeline Routing and Economic Analysis. Power plant Muara Tawar will substitute the need of oil fuel to gas as form of economizing and energy conservation. The nearest supply point to fulfill natural gas needed on Muara Bekasi. So that Power Plant Company needed to develop gas pipeline infrastructure to joining the point.The purpose of this study is to create a system of gas transmission pipeline from gas supply point at Muara Bekasi to Power Plant Muara Tawar trough to offshore area. Design of gas transmission pipeline is started with technical data collection and …

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The 2005 Chios Ancient Shipwreck Survey: New Methods For Underwater Archaeology, Brendan P. Foley, Katerina Dellaporta, Dimitris Sakellariou, Brian S. Bingham, Richard Camilli, Ryan M. Eustice, Dionysis Evagelistis, Vicki Lynn Ferrini, Kostas Katsaros, Dimitris Kourkoumelis, Aggelos Mallios, Paraskevi Micha, David A. Mindell, Christopher Roman, Hanumant Singh, David S. Switzer, Theotokis Theodoulou Apr 2009

The 2005 Chios Ancient Shipwreck Survey: New Methods For Underwater Archaeology, Brendan P. Foley, Katerina Dellaporta, Dimitris Sakellariou, Brian S. Bingham, Richard Camilli, Ryan M. Eustice, Dionysis Evagelistis, Vicki Lynn Ferrini, Kostas Katsaros, Dimitris Kourkoumelis, Aggelos Mallios, Paraskevi Micha, David A. Mindell, Christopher Roman, Hanumant Singh, David S. Switzer, Theotokis Theodoulou

Graduate School of Oceanography Faculty Publications

In 2005 a Greek and American interdisciplinary team investigated two ship wrecks off the coast of Chios dating to the 4th-century B.C. and the 2nd/lst century. The project pioneered archaeological methods of precision acoustic, digital image, and chemical survey using an autonomous underwater vehicle (AUV) and in-situ sensors, increasing the speed of data acquisition while decreasing costs. The AUV recorded data revealing the physical dimensions, age, cargo, and preservation of the wrecks. The earlier wreck contained more than 350 amphoras, predominantly of Chian type, while the Hellenistic wreck contained about 40 Dressel 1C amphoras. Molecular biological analysis of two amphoras …

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Fuzzy Optimal Swarm Of Autonomous Aircrafts For Target Determination And Convergence Control System, Zach D. Richards Jan 2009

Fuzzy Optimal Swarm Of Autonomous Aircrafts For Target Determination And Convergence Control System, Zach D. Richards

Electronic Theses and Dissertations

The thesis project proposes analytical and theoretical algorithms for a networked swarm of autonomous vehicles, such as those used in planet exploration, and to be used in target location determination and convergence, an algorithm of this type could be used in an Autonomous Stratospheric Aircraft (ASA), thus having the possibility of being used for the exploration of a planet as well as many other applications. Upon locating an unknown location of a specified target, the algorithm would then swarm and eventually converge upon the location. There are two similar, but fundamentally different algorithms proposed in this project. These algorithms are …

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Heterogeneous Drive Mechanisms For Novel Locomotion In Rough Terrain, Roy Godzdanker Jan 2009

Heterogeneous Drive Mechanisms For Novel Locomotion In Rough Terrain, Roy Godzdanker

Electronic Theses and Dissertations

The smaller the robot the easier it is for it to access voids in a collapsed structure, however small size brings a host of other problems related to constrained resources. One of the primary constraints on small robots is limited motive power to surmount obstacles and navigate rough terrain. This thesis examines the addition of bulk motive force actuators to existing locomotion platforms and the impact of these heterogeneous actuators on conventional steering methods. The steering methods examined are those associated with skid steered vehicles and differential drive vehicles. In developing the Crabinator, a robot composed of a limbed crawler …

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System Design And Integration For Repeated Impact Tests, Cheng Lin, Gene Hou, Sebastian Bawab, Timothy Coats, Hesham Nassar Jan 2009

System Design And Integration For Repeated Impact Tests, Cheng Lin, Gene Hou, Sebastian Bawab, Timothy Coats, Hesham Nassar

Engineering Technology Faculty Publications

The design and integration of an impact-testing machine is particularly for the test of an object which is repeatedly dropped down from a specified height. Four linear actuators with two on each of the two magnetic rails are used to lift up an object weighing up to 70 lbs. Each actuator is powered and controlled by an industrial amplifier. A Programmable Logical Controller (PLC) is applied to activate these four actuators simultaneously and repeatedly. Accelerometers using an National Instruments (NI) data acquisition system are used to measure the impact force during the tests. Students gain design and implementation experiences from …

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Isolation Of Methyl Laurate From Coconut Oil As Raw Material For Fatty Alcohol Sulfate, Rita Arbianti, Tania Surya Utami, Astri Nugroho Nov 2008

Isolation Of Methyl Laurate From Coconut Oil As Raw Material For Fatty Alcohol Sulfate, Rita Arbianti, Tania Surya Utami, Astri Nugroho

Makara Journal of Technology

Isolation of Methyl Laurate from Coconut Oil as Raw Material for Fatty Alcohol Sulfate. Methyl laurate is a raw or base material for many industries, including surfactant industries. In this research, coconut oil (VCO) is transesterified with methanol to produce methyl ester, using NaOH as the catalyst. Methyl laurate is then separated by method based on the difference in melting point. This research focuses at determining the effects of some variables in transesterification on the concentration of produced methyl laurate. The variables are temperature (40 oC, 50 oC, 60 oC, 80 oC), time of transesterification reaction (0,5 hour, 1 hour, …

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The Decompositioning Of Volatile-Matter Of Tanjung Enim Coal By Using Thermogravimetry Analyzer (Tga), Nukman Nukman Nov 2008

The Decompositioning Of Volatile-Matter Of Tanjung Enim Coal By Using Thermogravimetry Analyzer (Tga), Nukman Nukman

Makara Journal of Technology

The Decompositioning of Volatile-Matter of Tanjung Enim Coal by using Thermogravimetry Analyzer (TGA). Coal is a nature material which a kind of energy source. The decompotition of coal could analyze by heat treated using thermogravimetry analyzer. The decomposition of the volatile matter for three kinds of Tanjung Enim coal could be known. The value of activation energy that be found diference, then for Semi Anthracite, Bitumonius and Sub Bituminous Coal, the initial temperatures are 60.8 oC, 70.7 oC, 97.8oC, and the last temperatures are 893.8 oC, 832 oC, 584.6oC.

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Phase Unwrapping Insar Image Using Local Energy Minimization Approach, Kusworo Adi, Tati L.R. Mengko, Andriyan B. Suksmono, Hendra Gunawan Nov 2008

Phase Unwrapping Insar Image Using Local Energy Minimization Approach, Kusworo Adi, Tati L.R. Mengko, Andriyan B. Suksmono, Hendra Gunawan

Makara Journal of Technology

Phase Unwrapping InSAR Image Using Local Energy Minimization Approach. Reconstruction process of phase data from its cover is called Phase Unwrapping (PU). Ideally, without any noise phrase, singularity, and aliasing problems, the phase information can be unwrapped easily. However, in fact, the phase data actually always get noise disturbance and discontinuity. The PU process becomes more complicated and needs a better PU algorithm to address the problems properly. In this research, the local PU algorithm is developed using minimization of close related firstorder pixels energy approach. In this method, the energy difference between four close related pixels is counted, followed …

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Two Element Microstrip Antenna Array With Defected Ground Structure, Fitri Yuli Zulkifli, Eko Tjipto Rahardjo, Muhamad Asvial, Djoko Hartanto Nov 2008

Two Element Microstrip Antenna Array With Defected Ground Structure, Fitri Yuli Zulkifli, Eko Tjipto Rahardjo, Muhamad Asvial, Djoko Hartanto

Makara Journal of Technology

Two Element Microstrip Antenna Array with Defected Ground Structure. This paper presents a two element microstrip antenna array using trapezium shape defected ground structure (DGS). The DGS is inserted in the ground plane between two elements of antenna array. Insertion of the DGS is intended to suppress the mutual coupling effect produced by antenna array. Simulation and measurement results were taken and compared between antenna array with and without DGS. Measurement results show that the antenna with DGS compared to antenna without DGS can suppress mutual coupling effect to 7.9 dB, improve the return loss to 33.29% from -30.188 dB …

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Neutron Irradiation On Ss316 Material For Radioactive Endovascular Stent Production, Rohadi Awaludin, Abidin Abidin, Sriyono Sriyono Nov 2008

Neutron Irradiation On Ss316 Material For Radioactive Endovascular Stent Production, Rohadi Awaludin, Abidin Abidin, Sriyono Sriyono

Makara Journal of Technology

Neutron Irradiation on SS316 Material for Radioactive Endovascular Stent Production. It was reported that restenosis could be prevented by radioactive endovascular stent. SS316 material of endovascular stent has been irradiated at pneumatic rabbit system of G.A. Siwabessy reactor for 5 minutes for producing radioactive stent by neutron activation. After 10 days of decay, the irradiated SS316 was measured by gamma spectrometer. The radioisotopes of 51Cr, 59Fe and 60Co were detected in the irradiated SS316 with radioactivity of 5990, 107 and 109 Bq/mg respectively. The Calculation results showed that radioisotopes of 51Cr, 59Fe and 55Fe were produced by neutron activation. The …

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