cover
Article Per Year (5 Year)
All
Home Page
OAI Link
Editorial Team
Contact
Reviewer
Google Scholar
Contact Name
Dr. Basari
Contact Email
basari.st@ui.ac.id
Phone
+6221-29120943
Journal Mail Official
editor_mst@ui.ac.id
Editorial Address
Universitas Indonesia ILRC Building, 1st Floor, Depok 16424, Indonesia Kota depok, Jawa barat INDONESIA
Location
Kota depok,
Jawa barat
INDONESIA
Makara Journal of Technology
Published by Universitas Indonesia
ISSN : 23552786     EISSN : 23564539     DOI : https://doi.org/10.7454/mjt
Core Subject : Science, Engineering,
Chemical Engineering, Chemistry & Bioengineering Civil Engineering, Building, Construction & Architecture Electrical & Electronics Engineering Engineering Materials Science & Nanotechnology Mechanical Engineering
MAKARA Journal of Technology is a peer-reviewed multidisciplinary journal committed to the advancement of scholarly knowledge and research findings of the several branches of Engineering and Technology. The Journal publishes new results, original articles, reviews, and research notes whose content and approach are of interest to a wide range of scholars. It also offers rapid dissemination. MAKARA Journal of Technology covers the recent research in several branches of engineering and technology include Electrical & Electronics Engineering, Computer Engineering, Mechanical Engineering, Chemical & Bioprocess Engineering, Material & Metallurgical Engineering, Industrial Engineering, Civil & Architecture Engineering, and Marine Engineering. Criteria used in determining acceptability of contributions include newsworthiness to a substantial part of the engineering & technology and the effect of rapid publication on the research of others. This journal, published three times each year, is where readers look for the advancement of discoveries in engineering and technology.
Arjuna Subject : Teknik (semua kategori) - Teknik (Lain-Lain)
Articles 485 Documents
 8   9   10   11   12 
Biogasoline Production from Palm Oil Via Catalytic Hydrocracking over Gamma-Alumina Catalyst Wijanarko, Anondho; Mawardi, Dadi Ahmad; Nasikin, Mohammad
Makara Journal of Technology Vol. 10, No. 2
Publisher : UI Scholars Hub

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Biogasoline Production from Palm Oil Via Catalytic Hydrocracking over Gamma-Alumina Catalyst. Bio gasoline conversion from palm oil is an alternative energy resources method which can be substituted fossil fuel base energy utilization. Previous research resulted that palm oil can be converted into hydrocarbon by catalytic cracking reaction with γ-alumina catalyst. In this research, catalytic cracking reaction of palm oil by γ-alumina catalyst is done in a stirrer batch reactor with the oil/catalyst weight ratio variation of 100:1, 75:1, and 50:1; at suhue variation of 260 to 340oC and reaction time variation of 1 to 2 hour. Post cracking reaction, bio gasoline yield could be obtained after 2 steps batch distillation. Physical property test result such as density and viscosity of this cracking reaction product and commercial gasoline tended a closed similarity. According to result of the cracking product’s density, viscosity and FTIR, it can conclude that optimum yield of the palm oil catalytic cracking reaction could be occurred when oil/catalyst weight ratio 100:1 at 340 oC in 1.5 hour and base on this bio gasoline’s FTIR, GC and GC-MS identification results, its hydrocarbons content was resembled to the commercial gasoline. This palm oil catalytic cracking reaction shown 11.8% (v/v) in yield and 28.0% (v/v) in conversion concern to feed palm oil base and produced a 61.0 octane number’s bio gasoline.
A Study on Parallel Computation Tools on Networked PCs Suhartanto, Heru
Makara Journal of Technology Vol. 10, No. 2
Publisher : UI Scholars Hub

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

A Study on Parallel Computation Tools on Networked PCs. Many models for natural phenomena, engineering applications and industries need powerfull computing resources to solve their problems. High Performance Computing resources were introduced by many researchers. This comes in the form of Supercomputers and with operating systems and tools for development such as parallel compiler and its library. However, these resources are expensive for the investation and maintenance, hence people need some alternatives. Many people then introduced parallel distributed computing by using available computing resource such as PCs. Each of these PCs is treated as a processors, hence the cluster of the PC behaves as Multiprocessors Computer. Many tools are developed for such purposes. This paper studies the peformance of the currently popular tools such as Parallel Virta\ual Machine (PVM), Message Passing Interface (MPI), Java Remote Method Invocation (RMI) and Java Common Object Request Broker Architecture (CORBA). Some experiments were conducted on a cluster of PCs, the results show significant speed up. Each of those tools are identified suitable for a certain implementation and programming purposes.
Crude Oil Sludge Degradation in Microcosmic Scale: Simple Simulation as Preliminary Study on Land Treatment Bioremediation. Nugroho, Astri
Makara Journal of Technology Vol. 10, No. 2
Publisher : UI Scholars Hub

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Crude Oil Sludge Degradation in Microcosmic Scale: Simple Simulation as Preliminary Study on Land Treatment Bioremediation. A study in microcosmic condition has been carried out to evaluate the bacterial hydrocarbonoclastic capability in increasing the oil sludge degradation being mixed with NPK fertilizer as nitrogen resources. Aerobic test was carried out by putting erlenmeyers in a shaker incubator, 120 rpm shaking speed, at 50°C temperature. While 150 days in microcosmic one observation showed that the consortium has the potential to grow up to 50% (v/v) sludge oil load. Maximum growth and maximum growth rate of the consortium occurred in the III C treatment (by adding 50% (v/v) sludge oil and by mixing nitrogen in the form of NPK fertilizer amounting 30% (w/v) of added substrat. The observation showed that at the day 150, all the treatments were degradated above 64%. Highest degradation accured in the III A treatment followed by the III C treatment amounting 88.72% and 87.19% respectively. The gas chromatography analysis showed that at t15 and t30, hydrocarbon C8 and C9 turned up and then vanished after t30. Hydrocarbon do increased at t30 while the relative abundance of C11 up to C17 was decreasing gradually. The biggest decreasing of that was in C14, as 85.28% before and 43.11% after. At the end of the study 7 species of bacteria were identified, 5 of them are of Bacillus sp, which are aerobical.
Stress Corrosion Cracking Behavior of Stainless Steel 304 in the Sulfuric Acid Environment Due to Prestrain Badaruddin, Mohammad; Suudi, Ahmad; Hamni, Arinal
Makara Journal of Technology Vol. 10, No. 2
Publisher : UI Scholars Hub

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Stress Corrosion Cracking Behavior of Stainless Steel 304 in the Sulfuric Acid Environment Due to Prestrain. The aim of research is to investigate the effect of prestrain on the stress corossion cracking behavior of AISI 304 stainless steel in the sulfuric acid of 10% concentration under the static cantilever loading according to ASTM E-1681 standart. The specimen of 304 Stainless steel was strain up over the yield strength until reaching the uniform strain of 5% and 10% using servopulser UTM 9506 under the displacement control of 0,3 mm/sec. The results of test show that the prestrain of 5% specimen is faster failure than both of the prestrain of 10% and unprestrain specimen. It was caused by both of the decrease of ductility and the short incubation period. The change of deflection could be only recorded under the loading 20% of yield strength. Intergranular crack was the prestrain of 10% specimen under the static loading of 616 MPa. Whereas, for the prestrain of 10% specimen transgranular crack was found under the static loading of 554,4 MPa. The prestrain of 5% specimen was mixed crack under the static loading of 369.6 MPa. Higher dislocation density on the layer surface due to plastic deformation with increasing the percentage of pre-strain, so more difficult hydrogen diffused into the crack tip. Consequently, The incubation period can be prolonged.
Determination of Operation Condition and Product Dimension Accuracy Optimization of Filament Deposition Modelling on Layer Manufacturing Application Widyanto, Slamet A.; Tontowi, Alva Edy; Jamasri, Jamasri; Rochardjo, Heru Santoso Budi
Makara Journal of Technology Vol. 10, No. 2
Publisher : UI Scholars Hub

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Layer manufacturing process has proven as a process that can produce a high complexity mechanical part. Now, Improvement of LM methods continuously conduct that is aimed to increase precessions and efficiency of these processes. Pressure filament deposition modelling is a form of layer manufacturing process that is designed to produce a plastic part with controlling its semisolid phase. In this research, the equipment of filament depositor is designed and tested to make the product filament deposition. With operation condition observation, the optimal temperature and pressure of deposition process was determined. These experiments used PVC as crystalline material and polypropylene as amorphous material. To optimize this process, the tensile strength and density test were conducted. The shape of tensile test specimens is based on ASTM 638 standard and made in 3 orientations deposition path, namely: in 0 degree, 45 degree and 90 degree from load force axis. To found the most accurate dimension, controlling the time delay, temperature of build part, feeding speed and variation deposition path was conducted. The results of experiments show that the filament deposition method can only be applied for amorphous material in which it has a semisolid phase. From the tensile strength test, the binding strength among filaments is 0.5 kg/mm2, 20% of the tensile strength of filament. And the density of a sample product, which used the filament diameter of 0.8 mm, is 0.7668 g/cm3. Accuracy of product dimension can be increased by: controlling time delay in location where the motion orientation of hopper filament is changed and controlling temperature of build part surface.
Magnetic Field Effects on CaCO3 Precipitation Process in Hard Water Saksono, Nelson; Bismo, Setijo; Krisanti, Elsa; Manaf, Azwar; Widaningrum, Roekmijati
Makara Journal of Technology Vol. 10, No. 2
Publisher : UI Scholars Hub

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Magnetic Field Effects on CaCO3 Precipitation Process in Hard Water. Magnetic treatment is applied as physical water treatment for scale prevention especially CaCO3, from hard water in piping equipment by reducing its hardness. Na2CO3 and CaCl2 solution sample was used in to investigate the magnetic fields influence on the formation of particle of CaCO3. By changing the strength of magnetic fields, exposure time and concentration of samples solution, this study presents quantitative results of total scale deposit, total precipitated CaCO3 and morphology of the deposit. This research was run by comparing magnetically and non-magnetically treated samples. The results showed an increase of deposits formation rate and total number of precipitated CaCO3 of magnetically treated samples. The increase of concentration solution sample will also raised the deposit under magnetic field. Microscope images showed a greater number but smaller size of CaCO3 deposits form in magnetically treated samples, and aggregation during the processes. X-ray diffraction (XRD) analysis showed that magnetically samples were dominated by calcite. But, there was a significant decrease of calcite’s peak intensities from magnetized samples that indicated the decrease of the amount of calcite and an increase of total amorphous of deposits. This result showed that magnetization of hard water leaded to the decreasing of ion Ca2+ due to the increasing of total CaCO3 precipitation process.
Reverse Link CDMA System Capacity Evaluation for Stratospheric Platform Mobile Communications Iskandar, Iskandar
Makara Journal of Technology Vol. 11, No. 2
Publisher : UI Scholars Hub

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

We propose an analysis of reverse link CDMA multispot beam stratospheric platforms (SPF) in this paper. The SPF is currently proposed as a novel wireless technology for the development of the next generation fixed and mobile communications. The geometry of this technology is different from that of the terrestrial but rather similar to the satellite based cellular system. However, evaluation on the CDMA system capacity of this technology has not been much reported. This paper addresses all possible multiple access interference analyses including the effects of channel fading and shadowing in order to evaluate the system capacity. Single SPF and multiple SPF model are evaluated under perfect power control and imperfect power control. The results indicate that in SPF systems the reverse link CDMA capacity is significantly reduced because of the power control imperfections. Moreover, in multiple SPF model the interference caused by the users in overlapped region is not trivial. We found that because of this problem the capacity is reduced for both speech and real-time data applications compared with the single SPF model even though the assumption of perfect power control can be made. In order to improve the system capacity we proposed two methods, first is to increase the minimum elevation angle definition for each platform and the second is to employ an adaptive antenna.
Trajectory Shaping of Surface-to-Surface Missile with Terminal Impact Angle Constraint Subchan, S.
Makara Journal of Technology Vol. 11, No. 2
Publisher : UI Scholars Hub

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

This paper presents trajectory shaping of a surface-to-surface missile attacking a fixed with terminal impact angle constraint. The missile must hit the target from above, subject to the missile dynamics and path constraints. The problem is reinterpreted using optimal control theory resulting in the formulation of minimum integrated altitude. The formulation entails nonlinear, two-dimensional missile flight dynamics, boundary conditions and path constraints. The generic shape of optimal trajectory is: level flight, climbing, diving; this combination of the three flight phases is called the bunt manoeuvre. The numerical solution of optimal control problem is solved by a direct collocation method. The computational results is used to reveal the structure of optimal solution which is composed of several arcs, each of which can be identified by the corresponding manoeuvre executed and constraints active.
Analysis of three phase controlled rectifier with the same distance control as compared to the same angle control S., Sudirman; A., Sri Kurniati
Makara Journal of Technology Vol. 11, No. 2
Publisher : UI Scholars Hub

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Analysis of three phase controlled rectifier with the same distance control as compared to the same angle control. This research aim to compare the firing of the same distance and the same angle control at three phase controlled rectifier with seen generated harmonic at input (AC side). Then calculate of rectifier efficiency and power factor comparison from both the control type. The rectifier use passive filter with resistance 11 ohm and is analysed with program simulation using PSPICE version 7.1. Result of research indicate that use of the same distance control generates the 5th and 7th harmonics, while the same angle control generates the 3rd , 5th and 7th harmonics at the input (AC side). At the output (DC side), the same distance control type generates the 6th voltage ripples, while the same angle control generates the 2nd, and 6th voltage ripples. The result of calculation of voltage ripples that happened equal to 3.5% with efficiency 99.8% at same distance control, while at the same angle control obtained voltage ripples equal to 4% with efficiency 99.7% . At the firing angle 300 obtained by THD input equal to 50.26% with power factor equal to 0.89 at same distance control type, while the same angle control obtained by THD input equal to 53,831% with power factor to 0,87. From this result indicate that the firing of thyristor with the same distance better then is the same angle control.
The Potency of Fire and Explosion Hazard on Premium Oil Storage Tank at Depot X 2007 Lestari, Fatma; Nurdiansyah, Warid
Makara Journal of Technology Vol. 11, No. 2
Publisher : UI Scholars Hub

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

The Potency of Fire and Explosion Hazard on Premium Oil Storage Tank at Depot X 2007. Premium oil storage tanks have fire and explosion risk because Premium oil is flammable liquid. Because of that, fire and explosion risk assessment on Premium oil storage tank at Depot X is needed as foundation to fire and explosion risk management, and comply with regulations. Method of this research is Dow’s Fire and Explosion Index. This research indicate that F&EI value for Premium oil storage tank is 118,82. Based on that F&EI value, level of risk at Premium oil storage tank is intermediate risk.

Page 10 of 49 | Total Record : 485

 8   9   10   11   12 

Filter by Year

2002 2025


Reset
Filter By Issues
All Issue Vol. 29, No. 2 Vol. 29, No. 1 Vol. 28, No. 3 Vol. 28, No. 2 Vol. 28, No. 1 Vol. 27, No. 3 Vol. 27, No. 2 Vol. 27, No. 1 Vol. 26, No. 3 Vol. 26, No. 2 Vol. 26, No. 1 Vol. 25, No. 3 Vol. 25, No. 2 Vol. 25, No. 1 Vol. 24, No. 3 Vol. 24, No. 2 Vol. 24, No. 1 Vol. 23, No. 3 Vol. 23, No. 2 Vol. 23, No. 1 Vol. 22, No. 3 Vol. 22, No. 2 Vol. 22, No. 1 Vol. 21, No. 3 Vol. 21, No. 2 Vol. 21, No. 1 Vol. 20, No. 3 Vol. 20, No. 2 Vol. 20, No. 1 Vol. 19, No. 3 Vol. 19, No. 2 Vol. 19, No. 1 Vol. 18, No. 3 Vol. 18, No. 2 Vol. 18, No. 1 Vol. 17, No. 3 Vol. 17, No. 2 Vol. 17, No. 1 Vol. 16, No. 2 Vol. 16, No. 1 Vol. 15, No. 2 Vol. 15, No. 1 Vol. 14, No. 2 Vol. 14, No. 1 Vol. 13, No. 2 Vol. 13, No. 1 Vol. 12, No. 2 Vol. 12, No. 1 Vol. 11, No. 2 Vol. 11, No. 1 Vol. 10, No. 2 Vol. 10, No. 1 Vol. 9, No. 2 Vol. 9, No. 1 Vol. 8, No. 3 Vol. 8, No. 2 Vol. 8, No. 1 Vol. 7, No. 3 Vol. 7, No. 2 Vol. 7, No. 1 Vol. 6, No. 3 Vol. 6, No. 2 Vol. 6, No. 1 More Issue