Open Access. Powered by Scholars. Published by Universities.®
- Institution
- Keyword
-
- A356 alloy (1)
- AA319 (1)
- AQM (1)
- Absorption kinetic (1)
- Absorption with chemical reaction (1)
-
- Activation energy (1)
- Ad hoc hybrid (1)
- Al-Fe-Mn-Si (1)
- Al2Cu (1)
- Biohydrogen (1)
- Blast resistance (1)
- Boundary layers (1)
- Building fire safety (1)
- CO2 (1)
- Chattering (1)
- Chinese script (1)
- Chlorella vulgaris Buitenzorg (1)
- Coal (1)
- Coconut oil (1)
- Congestion control (1)
- Defected ground structure (1)
- Desulfurization (1)
- Devolatisation (1)
- Diffuser valve (1)
- Dq model (1)
- Emergency response planning (1)
- Energy (1)
- Energy minimization (1)
- Fatty alcohol sulfate (1)
- Fire safety audit (1)
Articles 1 - 29 of 29
Full-Text Articles in Engineering
Study On Mechanical Properties Of A356 Alloys Enhanced With Preformed Thixotropic Structure, Shueiwan H. Juang, Shyh-Ming Wu
Study On Mechanical Properties Of A356 Alloys Enhanced With Preformed Thixotropic Structure, Shueiwan H. Juang, Shyh-Ming Wu
Journal of Marine Science and Technology
A preformed A356 alloys with thixotropic structure (designated SSM-A356) was systematically studied on mechanical properties in order to establish the database for further investigations in forming and heat treatment. Because of the specific microstructure and characteristics, the heat treatment conditions of SSM-A356 were explored through the observations of microstructure and the measurement of micro-hardness. In the investigation of heat treatment, it was observed that the eutectic silicon was refined and spheroidized which is unlikely for conventional processing. The mechanical testing results showed that the yield and ultimate tensile strength of SSM-A356 were respectively around 115% and 34% greater than those …
Variable-Thickness Boundary Layers For Sliding Mode Control, Chyun-Chau Fuh
Variable-Thickness Boundary Layers For Sliding Mode Control, Chyun-Chau Fuh
Journal of Marine Science and Technology
Sliding mode control is a nonlinear feedback control technique which provides good robustness against modeling uncertainties and external disturbances. However, as the uncertainties or disturbances increase, a greater control input is required, and the control signal may cause an undesirable chattering phenomenon. In general, the further the system trajectory from the origin, the more violent the chattering effect. However, as the trajectory moves closer to the origin, the degree of chattering gradually reduces. As a result, even if an attempt is made to eliminate chattering by introducing a small constant boundary layer around the sliding surface, the chattering phenomenon may …
Isolation Of Methyl Laurate From Coconut Oil As Raw Material For Fatty Alcohol Sulfate, Rita Arbianti, Tania Surya Utami, Astri Nugroho
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, …
Two Element Microstrip Antenna Array With Defected Ground Structure, Fitri Yuli Zulkifli, Eko Tjipto Rahardjo, Muhamad Asvial, Djoko Hartanto
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 …
Physical Characteristics And Utilization Oft The Karst Beaches In Kabupaten Gunungkidul, Astrid Damayanti, Ranum Ayuningtyas
Physical Characteristics And Utilization Oft The Karst Beaches In Kabupaten Gunungkidul, Astrid Damayanti, Ranum Ayuningtyas
Makara Journal of Technology
Physical Characteristics and Utilization oft the Karst Beaches in Kabupaten Gunungkidul. Karsts beaches at Gunungkidul Regency (Baron, Kukup, Sepanjang, Drini, Krakal, Ngandong, and Sundak), located in south of Daerah Istimewa Yogyakarta Province, have economic potential. Even they have similarity in geological condition (genesis and morphological processes), but they have different physical characteristics. Based on result of observation environment on morphological conditions and spatial analysis method, we found the proper utilization of the beaches.
The Decompositioning Of Volatile-Matter Of Tanjung Enim Coal By Using Thermogravimetry Analyzer (Tga), Nukman Nukman
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.
Hydrogen Absorption In Weldments Of Overlaid Claded Pressure Vessel, Ronnie Higuchi Rusli
Hydrogen Absorption In Weldments Of Overlaid Claded Pressure Vessel, Ronnie Higuchi Rusli
Makara Journal of Technology
Cracks was found in type 347 stainless steel internal attachment welds of a reactor for a high temperature, and high pressure hydrogen service. One of the possible causes of cracking is low cycle fatigue cracking induced by repetition of thermal stress to embrittled weld metal. Type 347 weld metal loses its ductility by presence of sigma phase and hydrogen.
Phase Unwrapping Insar Image Using Local Energy Minimization Approach, Kusworo Adi, Tati L.R. Mengko, Andriyan B. Suksmono, Hendra Gunawan
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 …
Neutron Irradiation On Ss316 Material For Radioactive Endovascular Stent Production, Rohadi Awaludin, Abidin Abidin, Sriyono Sriyono
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 …
Spectral Response Surfaces And The Ringing Response Of Offshore Structures, I Ketut Suastika
Spectral Response Surfaces And The Ringing Response Of Offshore Structures, I Ketut Suastika
Makara Journal of Technology
A method, called spectral response surface method, is proposed for the study of the ringing phenomenon of offshore structures. Newman’s results for diffraction force on a column were reformulated in terms of the frequency components of the ocean surface and their Hilbert transforms. Using a first-order reliability method together with a dynamic model for the structural response, it is straightforward to calculate the ocean surface history most likely to generate an extreme ringing response and the ringing response history.
Developing A Convective Code With Vorticity Transport In Upwind Method, Je -Ee Ho
Developing A Convective Code With Vorticity Transport In Upwind Method, Je -Ee Ho
Journal of Marine Science and Technology
The Navier-Strokes equations are usually used to solve the convective problems, however, to satisfy the conversation of mass, the uncertainty of pressure terms will easily trigger off the numerical divergence during the iterative process; which results in a calculating failure and makes the numerical solutions impossible. In this study, a vorticity–transport method that avoids the involvement of pressure terms by cross differentiate the governing equations and meets the flow conservation with stream function was proposed. With the aid of the upwind scheme and implicit method, an effective transformation from the partial differential equations into the vortex potential algebraic equations would …
Characteristic Study Of Mhd Minipump, Je -Ee Ho
Characteristic Study Of Mhd Minipump, Je -Ee Ho
Journal of Marine Science and Technology
The present study aims to develop and discuss the availability of the Magneto Hydrodynamics Minipump (MHD) as a miniaturizative part specified for precise manufacturing or medical application. Based on the MHD theory, an available working current (1.8A) induced by lower voltage (0-12V) and weaker magnetic intensity (0.04T) meets the need in mini-system operation. However, precise estimations of working capacity, maximum head, dynamic head, and static head in various electrolyte concentrations are necessary. Furthermore, this work also provides a simplified analytic model with a static balance between Lorentz force, surface tension force, and body force. Compared with analytic solutions and experimental …
Optimization Of Diffuser Valves, Chin-Tsan Wang, Pi-Cheng Chang, Chien-Cheng Huang
Optimization Of Diffuser Valves, Chin-Tsan Wang, Pi-Cheng Chang, Chien-Cheng Huang
Journal of Marine Science and Technology
In this study, the width of channel, D, and diffuser angle, , at given diffuser width whose value is 100 m will be studied for steady and unsteady flow conditions. By means of a series of numerical simulations, some findings for diffuser valve will be reported. The diffuser valve with a channel width of D = 300 m and diffuser angle =60º, is a better geometry because of its outstanding capability on suction production of net volume flow. Besides, the larger the Reynolds number is, the greater the suction amount of net volume flow will be. When the aspect ratio …
Investigation On The Blast Resistance Of A Stiffened Door Structure, Ming-Wei Hsieh, Jui-Pin Hung, De-Jen Chen
Investigation On The Blast Resistance Of A Stiffened Door Structure, Ming-Wei Hsieh, Jui-Pin Hung, De-Jen Chen
Journal of Marine Science and Technology
This study was aimed at investigating the blast resistance of a stiffened door structure. For this, a series of finite element transient analysis were performed to predict the dynamic response of blast resistant doors. Current results show that the stiffeners have sustained the majority of the explosive loadings. The effect of stiffener size on the stress state was rated in terms of the ratio of stiffener stress to plate stress, which was enhanced with the increase of web thickness of stiffener. Additional, the highest stresses were shown to occur at the transverse stiffeners near the hinged sides with a maximum …
The Effect Of Ozone And Zeolite Concentration To The Performance Of The Treatment Of Wastewater Containing Heavy Metal Using Flotation Process, Eva Fathul Karamah, Setijo Bismo, Hotdi M. Simbolon
The Effect Of Ozone And Zeolite Concentration To The Performance Of The Treatment Of Wastewater Containing Heavy Metal Using Flotation Process, Eva Fathul Karamah, Setijo Bismo, Hotdi M. Simbolon
Makara Journal of Technology
The Effect of Ozone and Zeolite Concentration to the Performance of the Treatment of Wastewater Containing Heavy Metal Using Flotation Process. Industrial wastewater which contains heavy metal cannot be disposed to the environment directly, due to its toxicity. In this research, separation of metal from wastewater was conducted by sorptive flotation method, using Lampung natural zeolite as bonding agent. The most common diffuser used in the flotation process is air or oxygen. In this research, ozone is used as diffuser because it is a stronger oxidant and more dissolvable in water than oxygen. Besides, ozone is a coagulant aid and …
The Development Of Inverter Fuzzy Logic Control For Induction Motor Control By Vector Control Method In Electric Vehicle, Era Purwanto, Mohammad Ashary, Subagio Subagio, Mauridhi Heri Purnomo
The Development Of Inverter Fuzzy Logic Control For Induction Motor Control By Vector Control Method In Electric Vehicle, Era Purwanto, Mohammad Ashary, Subagio Subagio, Mauridhi Heri Purnomo
Makara Journal of Technology
The development of Inverter Fuzzy Logic Control for Induction Motor Control by Vector Control Method in Electric Vehicle. In response to concerns about energy cost, energy dependence, and environmental damage, a rekindling of interest in electric vehicles (EV’s) has been obvious. Thus, the development of power electronics technology for EV’s will take an accelerated pace to fulfill the market needs, regarding with the problem in this paper is presented development of fuzzy logic inverter in induction motor control for electric vehicle propulsion. The Fuzzy logic inverter is developed in this system to directed toward developing an improved propulsion system for …
Internet Congestion Control System, Pranoto Hidaya Rusmin, Carmadi Machbub, Agung Harsoyo, Hendrawan Hendrawan
Internet Congestion Control System, Pranoto Hidaya Rusmin, Carmadi Machbub, Agung Harsoyo, Hendrawan Hendrawan
Makara Journal of Technology
Internet Congestion Control System. Internet congestion occurs when resource demands exceeds the network capacity. But, it is not the only reason. Congestion can happen on some users because some others user has higher sending rate. Then some users with lower sending rate will experience congestion. This partial congestion is caused by inexactly feedback. At this moment congestion are solved by the involvement of two controlling mechanisms. These mechanisms are flow/congestion control in the TCP source and Active Queue Management (AQM) in the router. AQM will provide feedback to the source a kind of indication for the occurrence of the congestion …
The Role Of 1 And 9 Wt.% Zn In Precipitation Hardening Of Aa319 Aluminium, Bondan Tiara Sofyan, Sari Susanti, Ridwan R. Yusfranto
The Role Of 1 And 9 Wt.% Zn In Precipitation Hardening Of Aa319 Aluminium, Bondan Tiara Sofyan, Sari Susanti, Ridwan R. Yusfranto
Makara Journal of Technology
The Role of 1 and 9 wt.% Zn in Precipitation Hardening of AA319 Aluminium. Aluminium alloys are widely used for automotive application due to its low density and high corrosion resistance. For economic reason, casting of automotive products always uses aluminium scrap as charging materials that may result in fluctuation of content of alloying element, such as Zn. This research studies the role of Zn in precipitation hardening of AA319 aluminium alloys. Hardness and tensile testing were conducted to study the mechanical properties of the alloys, while ageing response was followed by hardness measurements. Evolution of microstructures was observed by …
A Study Of Co2 Absorption Using Jet Bubble Column, Setiadi Setiadi, Nita Tania Hadiyani, Hantizen Hantizen, Dijan Supramono
A Study Of Co2 Absorption Using Jet Bubble Column, Setiadi Setiadi, Nita Tania Hadiyani, Hantizen Hantizen, Dijan Supramono
Makara Journal of Technology
A Study of CO2 Absorption Using Jet Bubble Column. The phenomenon of plunging jet gas-liquid contact occurs quite often in nature, it's momentum carries small air bubbles with it into the reactor medium. The momentum of the liquid stream can be sufficient to carry small bubbles completely to the bottom of the vessel. A stream of liquid falling toward a level surface of that liquid will pull the surrounding air along with it. It will indent the surface of the liquid to form a trumpet-like shape. If the velocity of the stream is high enough, air bubbles will be pulled …
Building Fire Safety Audit At Faculty X, University Of Indonesia, Year 2006, Fatma Lestari, Rm. Yodan Amaral Panindrus
Building Fire Safety Audit At Faculty X, University Of Indonesia, Year 2006, Fatma Lestari, Rm. Yodan Amaral Panindrus
Makara Journal of Technology
Building Fire Safety Audit at Faculty X, University of Indonesia, Year 2006. Fire may cause loss of life, material and valuable assets. The objective of this study is to conduct audit for fire safety and emergency response in the building at Faculty X, University of Indonesia, Depok. The audit results on the building fire safety facilities including emergency response and preparedness are then compared to the Building Code Australia (BCA) and Indonesian regulation on the building fire safety (Kep.MenPU.No 10 and 11/KPTS/2000). The building selected are Building A, B, C, D, F and G. Building classification for A, B, D, …
Substrates Preparation From Woody Tropical Waste Biomass For Biohydrogen Production, Dwi Susilaningsih, Theresia Umi Harwati, Khairul Anam, Yopi Yopi
Substrates Preparation From Woody Tropical Waste Biomass For Biohydrogen Production, Dwi Susilaningsih, Theresia Umi Harwati, Khairul Anam, Yopi Yopi
Makara Journal of Technology
Substrates Preparation from Woody Tropical Waste Biomass for Biohydrogen Production. Addressing to the global warming problem, energy crisis and pollution, hydrogen production by micro-organisms using biotechnological approach should be considered, since it fulfils the recent society requirement to safely produce, renewable and environmental friendly energy. Hydrogen is one of the most promising green energy sources, because it is easily converted to electricity and cleanly combustible. There are three types of micro-organisms for hydrogen production, the first is cyanobacteria through the photosynthesis process, the second is anaerobic bacteria, which use organic substances as electron donor and energy and convert them to …
Ad Hoc On-Demand Distance Vector (Aodv) Routing Protocol Performance Evaluation On Hybrid Ad Hoc Network: Comparison Of Result Of Ns-2 Simulation And Implementation On Testbed Using Pda, Riri Fitri Sari, Abdusy Syarif, Bagio Budiardjo
Ad Hoc On-Demand Distance Vector (Aodv) Routing Protocol Performance Evaluation On Hybrid Ad Hoc Network: Comparison Of Result Of Ns-2 Simulation And Implementation On Testbed Using Pda, Riri Fitri Sari, Abdusy Syarif, Bagio Budiardjo
Makara Journal of Technology
Ad Hoc on-Demand Distance Vector (AODV) Routing Protocol Performance Evaluation on Hybrid Ad Hoc Network: Comparison of Result of Ns-2 Simulation and Implementation on Testbed using PDA. In Mobile Ad hoc NETwork (MANET), node supplemented with wireless equipment has the capacity to manage and organise autonomously, without the presence of network infrastructures. Hybrid ad hoc network, enable several nodes to move freely (mobile) to create instant communication. Independent from infrastructure. They could access the Local Area Network (LAN) or the Internet. Functionalities of ad hoc network very much dependent on the routing protocol that determines the routing around node. Ad …
Biomass Production Chlorella Vulgaris Buitenzorg Using Series Of Bubble Column Photo Bioreactor With A Periodic Illumination, Anondho Wijanarko, Dianursanti Dianursanti, Muryanto Muryanto, Josia Simanjuntak, Praswasti Pembangun Dyah Kencana Wulan, Heri Hermansyah, Misri Gozan, Roekmijati Widaningroem Soemantojo
Biomass Production Chlorella Vulgaris Buitenzorg Using Series Of Bubble Column Photo Bioreactor With A Periodic Illumination, Anondho Wijanarko, Dianursanti Dianursanti, Muryanto Muryanto, Josia Simanjuntak, Praswasti Pembangun Dyah Kencana Wulan, Heri Hermansyah, Misri Gozan, Roekmijati Widaningroem Soemantojo
Makara Journal of Technology
Chlorella vulgaris Buitenzorg cultivation using three bubble column photo bioreactors arranged in series with a volume of 200 mL for 130 hours shows an increase of biomass production of Chlorella vulgaris Buitenzorg up to 1.20 times and a decrease of the ability of CO2 fixation compared to single reactor at a periodic sun illumination cycle. The operation conditions on cultivation are as following: T, 29.0oC; P,1 atm.; UG, 2.40 m/h; CO2, 10%; Benneck medium; and illumination source by Phillip Halogen Lamp 20W /12V/ 50Hz. Other research parameters such as microbial carbon dioxide transferred rate (qco2), CO2 transferred rate (CTR), energy …
Profile Design Of Piston Ring Using Inverse Method, Li-Ming Chu, Yuh-Ping Chang, Jung-Hua Yang
Profile Design Of Piston Ring Using Inverse Method, Li-Ming Chu, Yuh-Ping Chang, Jung-Hua Yang
Journal of Marine Science and Technology
This study aims to develop an algorithm for designing the piston ring profile and pressure distribution using an inverse method. The proposed algorithm needs to obtain load and boundary conditions for estimating not only a smooth curve in the piston ring profile, but also in the pressure distribution. The algorithm is developed from Reynolds integral and force balance equations. The least-squares error method, variational method, Gauss-Seidel method and Newton-Raphson method are employed to calculate the piston ring profile. Simulation results reveal that the greater the degree of the polynomial function used, the greater the maximum pressure ( Pmax ), load …
Fatigue Analysis Of An Inline Skate Axel, Garrett Hansen, Mike Woizeschke
Fatigue Analysis Of An Inline Skate Axel, Garrett Hansen, Mike Woizeschke
The Journal of Undergraduate Research
In this paper, an inline skate axel is analyzed based on fatigue and economic principles for four different materials. The loading scenario on the axel of the inline skate is derived and broken down to a maximum shear stress that must be less than the maximum fatigue stress of the axel material. A fatigue analysis using Goodman line diagrams is applied to axels made of aluminum, titanium, nylon, and PVC. The material strengths are then compared to the loading requirements and determined whether they would be sufficient for an axel material. Finally, the prices are compared to verify the selection …
Factors Affecting The Spread Of A Bioterrorist Agent Throughout A Building, William A. Cantrell
Factors Affecting The Spread Of A Bioterrorist Agent Throughout A Building, William A. Cantrell
Inquiry: The University of Arkansas Undergraduate Research Journal
Bioterrorism has become a greater concern for Americans since the 2001 anthrax letters. Recent studies have explored the possibilities of biological attacks, and most deal with possible large-scale attacks. However, there is reason to believe that small-scale attacks are more likely. Even though there have been investigations of the postal delivery system and the spread of bioagents through mail, few if any studies have looked at attack on a single building and the resultant spread form room to room. One particular method of attacking a building would be a single-even release of an aerosol bioagent in the building. This paper …
Analysis Of Wind Turbine Transverse Vibration, Matt Hein, Whitney Karpen
Analysis Of Wind Turbine Transverse Vibration, Matt Hein, Whitney Karpen
The Journal of Undergraduate Research
Large wind turbines have become an appealing choice for renewable electrical energy production throughout the world. The United States Midwest contains massive potential for wind energy development and is therefore being primed for large wind turbines to harvest this resource and bring it to market. Because of this, safety concerns have arisen in regard to their ability to withstand the harsh climate of the region. Analysis of the transverse vibration caused by severe weather will be preformed. A simplified model will allow for an analytical solution and displacement graphs produced with MATLAB code. This information will allow for an unbiased …