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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
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.
Articles 439 Documents
Study About High Influence Doping to Base Resistance and Bandgap Narrowing at Si/Si1-xGex/Si Heterojunction Bipolar Transistor Fadhol, Achmad
Makara Journal of Technology Vol. 7, No. 1
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Study About High Influence Doping to Base Resistance and Bandgap Narrowing at Si/Si1-xGex/Si Heterojunction Bipolar Transistor. Heterojunction is a link formed bedween two semiconductor materials and differend bandgap which has thinness under 50nm and grow the mixture of plate SiGe as bases. The link is an abrupt link or graded one. In this research learnt formulation of doping concentration influence to basis resistance and bandgap narrowing through Si/Si1-xGex/Si Heterojunction Bipolar Transistor with abrupt emitter-basis link, besides taking care to mobility and basis wide to basis resistance, it is also influence of mole fraction to bandgap power. From the result shows that doping concentration addition of NB=5.1018 cm-3 to NB=5.1020 cm-3 in basis can decrease resistance basis value about 3.6%, increase bandgap narrowing about 0.126, and increase collector current density for about 1.36 times to Ge 24%.
Influence of Strain Rate and Temperature of Hot Tension Testing on Mechanical Properties of Medium Carbon Steel S48C Priadi, Dedi; Setyadi, Iwan; Siradj, Eddy S.
Makara Journal of Technology Vol. 7, No. 1
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Influence of Strain Rate and Temperature of Hot Tension Testing on Mechanical Properties of Medium Carbon Steel S48C. The characterization of S48C by hot tension testing was done to understanding the influence of temperature and strain rate for S48C flow stress, that close relationship with its forge ability. The hot tension testing was performed on temperatures and strain rates variation (T 850, 900, 950 0C and έ 0,01;1 s-1). The result of hot tension testing showed that increasing temperature decreases ultimate tensile strength (UTS) and flow stress of S48C. The higher decreasing of UTS is on 950 0C about 85% from room temperature condition, while the higher decreasing of flow stress has occurred on 950 0C about 31 % compare to conditions of temperature 850 0C, strain 0,23 & strain rate (έ)1 second- 1 and about 27% compare to the same conditions but έ= 0,01 second-1 . For increasing strain rate from 0,01 to 1 second-1 on the temperature range (850-950 0C) increases UTS about 33 – 50 % and flow stress about 46–53%.
Photocatalytic Treatment of Heavy Metal Waste Cr(VI) withTiO2 Photocatalyst Slamet, Slamet; Syakur, Riyadi; Danumulyo, Wahyu
Makara Journal of Technology Vol. 7, No. 1
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Photocatalytic Treatment of Heavy Metal Waste Cr(VI) with TiO2 Photocatalyst. The photocatalytic reduction of hexavalent chromium/Cr(VI) using TiO2 and copper-doped TiO2 as photocatalysts have been studied in stirred tank and circulating photoreactors. All photocatalysts were characterized with FTIR (Fourier Transform Infra Red), BET (Brunauer-Emmett-Teller), XRD (X-Ray Diffraction) and SEM (Scanning Electron Microscope). TiO2 Merck and Degussa P-25 are the commercial photocatalysts used to compare the photocatalytic activity of all the prepared catalysts. Blank test experiments as well as the effect of dopants, EDTA (ethylenediaminetetraacetic acid) and activated carbon addition were studied. Cr(VI) reduction on various pH and initial Cr(VI) concentration were also conducted. The results of the experiments showed that the addition of EDTA as a hole scavenger can increases the activity of all catalysts at about 10%. Rate of Cr(VI) photoreduction is more feasible at low pH and low initial Cr(VI) concentration. The addition of activated carbon (AC) increases the photocatalytic activity at about 5% due to the synergy effect between catalyst and AC. Pure TiO2 powder prepared from TiCl4 has the highest activity in reducing Cr(VI) with the conversion of 80% due to the high crystalline (anatase) and surface area. Photoreduction of Cr(VI) over TiO2 film photocatalyst in circulating photoreactor has not shown a significant result yet. Therefore it is needed to improve furthermore the photoreactor system especially for the film type photocatalyst.
Development and Analysis of Geographic Information System for Electricity Network (Case Study: Surabaya Industrial Estate Rungkut in Surabaya). Awalin, Lilik Jamilatul; Sukojo, Bangun Muljo
Makara Journal of Technology Vol. 7, No. 1
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Development and Analysis of Geographic Information System for Electricity Network (Case Study: Surabaya Industrial Estate Rungkut in Surabaya). Geographic Information System (GIS) is a system of data which has spatial base. This may be cause has ability to process and analysis data quickly. The ability of GIS will be able to process the alternative in decision making. The need of electric power grows until recent time along with the existence of industrial sector expansion and land use expansion claim better service, large and balance stock of electric power. GIS is a solution for planning and managing data base system, for quickly service and professional service to consumer in Surabaya Industrial Estate Rungkut (SIER) Area. By using Arc View to process the data which has spatial base, and supported by energy and voltage data in Surabaya Industrial Estate Rungkut area, the resistance, current, voltage regulation, energy losses supplied by Surabaya Industrial Estate Rungkut can be calculated. The existence of GIS technology can assist the work process in operator level and the balance of electrical power efficiency.
The performance analysis of a unicast network when two protocols, SCTP (Stream Control Transmission Protocol) and TCP (Transmission Control Protocol) coexist in the network Budiardjo, Bagio; Thiotrisno, Michael
Makara Journal of Technology Vol. 7, No. 2
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This paper elaborates the performance analysis of a unicast network when two protocols, SCTP (Stream Control Transmission Protocol) and TCP (Transmission Control Protocol) coexist in the network. These two protocols are tested using File Transfer Protocol (FTP) and Constant Bit Rate (CBR) based traffic. From the simulations, it could be concluded that SCTP could achieve better throughput compared to TCP in both FTP and CBR based traffic, with sufficiently high fairness index of both intrafairness and interfairness. The increase of simulation time yields to the increase and relatively stable network performance. The increase of the number of sessions of small bandwidth applications resulted in the increase of troughput and link utilization. The simulations show that implementation of SCTP and TCP in a unicast network generally could be done without having to degrade the network performance, with relatively high fairness index, over 0.85 for various traffic variations.
Mapping of Ecosystems in Mount Bromo Using Remote Sensing Technology Sukojo, Bangun Muljo
Makara Journal of Technology Vol. 7, No. 2
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Mapping of Ecosystems in Mount Bromo Using Remote Sensing Technology. Covered land analyses of Landsat image have been done to get ecosystem types and map in Mount Bromo region using remote sensing technology. There are nine types of ecosystems in Mount Bromo region, i.e. primary forest, secondary forest, lake, crater, sands, uncovered land, underbrush, dry-field and residence. Distribution of rock analysis has also been done by comparing the manual image interpretation with geological map. The results were coorelated with the digital image interpretation to find rock distribution map which can be useful to get the information about water reservation potencial in Mount Bromo region. The coorelation results together with slope, covered vegetation and rain falls can give description about absolute water reservation and buffer zone map in Mount Bromo region.
Capacity of High-Speed Powerline Communication in Vehicles Hamdani, Deny; Safrianti, Ery
Makara Journal of Technology Vol. 7, No. 2
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Powerline Communication (PLC) Systems intents to use the mains network in vehicles for high-speed data transmission. Carrier frequencies in the range of MHz are required to establish data rates of some megabits per second. In this paper, typical reference channels extracted from channel measurements are presented and computation results of their capacities according to Shannon’s theorem are presented. Furthermore, the effect of limitations of frequency range and power spectral density of transmitted signal on achievable capacity is investigated. This paper outlines an assessment for theoretical channel capacity and achievable data rates of vehicular PLC transmission schemes. Finally, EMC (Electromagnetics Compatibility) constraint according to CISPR 25 (Comite International Special des Perturbations Radioelectrique – The International Special Committee on Radio Interference) is deeply considered.
Diffuser Optimation at Exhaust System with Catalytic Converter for 110 cc Mopet with Fluid Flow CFD Simulation Soemardi, Tresna P.; Siswantara, Ahmad Indra; Erwin, Erwin
Makara Journal of Technology Vol. 7, No. 2
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Diffuser Optimation at Exhaust System with Catalytic Converter for 110 cc Mopet with Fluid Flow CFD Simulation. CFD simulation used to get behavior of exhaust gas through catalyst, this result will be used to optimize geometry form to perform uniform stream distribution to catalyst, and CFD Simulation will used to analyze backpressure that happened at the model.
The Study on Fluorescence Characteristics of Chlorella spp: pH Influence on Culture P., Retno Wigajatri; Handojo, Andrianto; Kurniawan, Hendrik; Prihantini, N. B.
Makara Journal of Technology Vol. 7, No. 2
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The Study on Fluorescence Characteristics of Chlorella spp: pH Influence on Culture. Experiments for measuring the fluorescence characteristics of Chlorella spp. by using high stability and high repetition rate nitrogen laser of energy 5 mJ with pulse duration of 5 ns have been carried out. The results show that for a cell concentration range from 2,625 cells/ml up to 2,769,000 cells/ml, the fluorescence intensities at pada λ = 687 nm have a linear relationship with the cell concentration. It has been also found that for a 7 days old chlorella culture, the pH variation at the starting culture influenced the cell concentration.
Alum and PACl Coagulation Winarni, Winarni
Makara Journal of Technology Vol. 7, No. 3
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Alum and PACl Coagulation. Coagulation occurs by interaction of aluminum hydrolysis products with the contaminant such as colloidal particles. It is necessary to consider the different aluminum species that may present during specific conditions, since the mechanism of turbidity removal is dependent upon them. PACl consists of preformed aluminum hydrolysis products, which are stable below pH 6 and less sensitive than in situ hydrolysis product, alum. The benefits of PACl relative to alum have been investigated as a function of pH and Al dosages. Specific conditions and aluminum species that exist during the certain mechanisms of coagulation are discussed. Results suggest that PACl is more effective than alum in lower pH range and high pH range, whereas alum is optimum in the neutral condition.

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