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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
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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 8 Documents
Search results for , issue "Vol. 20, No. 3" : 8 Documents clear
Effect of Milling on the Densification of SiC-BasedComposites from Polysilazane Noviyanto, Alfian; Nishimura, Toshiyuki
Makara Journal of Technology Vol. 20, No. 3
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Abstract

High density SiC-based composites from polysilazane were fabricated by high energy milling and hot pressing. After cross-linking at 200 °C, the polysilazane was pyrolysed at 1000 °C in N2 for 2 h to form amorphous Si-C-N-O followed by high energy milling for 1 h. Milled amorphous Si-C-N-O was sintered in hot pressing at 1600 and 1700 °C for 1 h in vacuum under the applied pressure of 50 MPa. Although no sintering additives were used, dense SiC-based composites were obtained with this method. Sintered density was 3.04 g/cm3, while only 2.57 g/cm3 for amorphous Si-C-N-O without milling. It is suggested that the liquid phase generated during the formation of Si2N2O facilitated the densification of the composite.
Thermoeconomic Optimization of Cascade Refrigeration System Using Mixed Carbon Dioxide and Hydrocarbons at Low Temperature Circuit Nasruddin, Nasruddin; Arnas, Arnas; Faqih, Ahmad; Giannetti, Niccolo
Makara Journal of Technology Vol. 20, No. 3
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Abstract

Many applications and industrial processes require very low cooling temperature, such as cold storage in the biomedical field, requiring temperature below -80 °C. However, single-cycle refrigeration systems can only achieve the effective cooling temperature of -40 °C and, also, the performance of the cycle will decrease drastically for cooling temperatures lower than -35°C. Currently, most of cascade refrigeration systems use refrigerants that have ozone depletion potential (ODP) and global warming potential (GWP), therefore, in this study, a cascade system is simulated using a mixture of environmentally friendly refrigerants, namely, carbon dioxide and a hydrocarbon (propane, ethane or ethylene) as the refrigerant of the low temperature circuit. A thermodynamic analysis is performed to determine the optimal composition of the mixture of carbon dioxide and hydrocarbons in the scope of certain operating parameters. In addition, an economic analysis was also performed to determine the annual cost to be incurred from the cascade refrigeration system. The multi-objective/thermoeconomic optimization points out optimal operating parameter values of the system, to addressing both exergy efficiency and its relation to the costs to be incurred.
Characterization and Utilization of Calcium Oxide (CaO) Thermally Decomposed from Fish Bones as a Catalyst in the Production of Biodiesel from Waste Cooking Oil Lesbani, Aldes; Sitompul, Sabat Okta Ceria; Mohadi, Risfidian; Hidayati, Nurlisa
Makara Journal of Technology Vol. 20, No. 3
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Abstract

Thermal decomposition of fish bones to obtain calcium oxide (CaO) was conducted at various temperatures of 400, 500, 800, 900, 1000, and 1100 °C. The calcium oxide was then characterized using X-ray diffractometer, FTIR spectrophotometer, and SEM analysis. The calcium oxide obtained from the decomposition at 1000 °C was then used as a catalyst in the production of biodiesel from waste cooking oil. Diffraction pattern of the calcium oxide produced from decomposition at 1000 °C showed a pattern similar to that of the calcium oxide produced by the Joint Committee on Powder Diffraction Standard (JCDPS). The diffractions of 2q values at 1000 °C were 32.2, 37.3, 53.8, 64.1, and 67.3 deg. The FTIR spectrum of calcium oxide decomposed at 1000 °C has a specific vibration at wave-length 362 cm-1, which is similar to the specific vibration of Ca-O. SEM analysis of the calcium oxide indicated that the calcium oxide’s morphology shows a smaller size and a more homogeneous structure, compared to those of fish bones. The use of calcium oxide as a catalyst in the production of biodiesel from waste cooking oil resulted in iod number of 15.23 g/100 g KOH, density of 0.88 g/cm3, viscosity of 6.00 cSt, and fatty acid value of 0.56 mg/KOH. These characteristic values meet the National Standard of Indonesia (SNI) for biodiesel.
Optimizing Supply Chain Collaboration Based on Agreement Buyer-Supplier Relationship with Network Design Problem Sutopo, Wahyudi; Erliza, Ayu; Heryansyah, Arien
Makara Journal of Technology Vol. 20, No. 3
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Abstract

In recent years, the rising competitive environment with shorter product life cycles and high customization forces industries to increase their flexibility, speed up their response, and enhance concurrent engineering designs. To integrate these prospects, supply chain collaboration becomes a pertinent strategy for industries to strengthen their competitiveness. The network design problem is used to implement supply chain collaboration. In the buying and selling process, sharing information between buyer and supplier are important to obtain a transaction decision. The optimimum supply chain profit can be identified by mathematical model of network design problem. The Mathematical Model takes into consideration the uncertainity in negotiation of supply chain, transportation problems, and locationallocation of products from supplier to buyer in the planning based on the time value of money. The results show that the model can be used to optimize the supply chain profit. The supplier gets a profit because income were received in the initial contract, while the buyer profit comes from lower pay.
Expression and the Functional Study of Fusion Proteins α-Amylase and Hemolysin- αas an Application in Biofilm Polysaccharide Degradation Sugiarta, Gede Yuda; Wiseso, Anggoro; Sari, Siska Yuliana; Kamila, Etri Dian; Geraldine, Vanessa; Christina, Diana; Hanifi, Muhammad; Satyapertiwi, Dwiantari; Hertanto, Robby; Bela, Budiman; Yohda, Masafumi; Sahlan, Muhamad
Makara Journal of Technology Vol. 20, No. 3
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Abstract

Biofilm is an aggregate of consortium bacteria that adhere to each other on a surface. It is usually protected by the exopolysaccharide layer. Various invasive medical procedures, such as catheterization, endotracheal tube installation, and contact lens utilization, are vulnerable to biofilm infection. The National Institute of Health (NIH) estimates 65% of all microbial infections are caused by biofilm. Periplasmic α-amylase (MalS) is an enzyme that hydrolyzes α-1, 4- glicosidic bond in glycogen, starch, and others related polysaccharides in periplasmic space. Another protein called hemolysin-α (HlyA) is a secretion signal protein on C terminal of particular peptide in gram negative bacteria. We proposed a novel recombinant plasmid expressing α-amylase and hemolysin-α fusion in pSB1C3 which is cloned into E.coli to enable α-amylase excretion to extracellular for degrading biofilm polysaccharides content, as in starch agar. Microtiter assay was performed to analyze the reduction percentage of biofilm by adding recombinant E.coli into media. This system is more effective in degrading biofilm from gram positive bacteria i.e.: Bacillus substilis (30.21%) and Staphylococcus aureus (24.20%), and less effective degrading biofilm of gram negative i.e.: Vibrio cholera (5.30%), Pseudomonas aeruginosa (8.50%), Klebsiella pneumonia (6.75%) and E. coli (-0.6%). Gram positive bacteria have a thick layer of peptidoglycan, causing the enzyme to work more effectively in degrading polysaccharides.
Developing Road Infrastructure Route Planning: Increasing Feasibility of Toll Road Project Berawi, Mohammed Ali; Zagloel, Teuku Yuri; Miraj, Perdana; Berawi, Abdur Rohim Boy; Titaheluw, Wellsi; Karim, Saipol Bari Bin Abd
Makara Journal of Technology Vol. 20, No. 3
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Abstract

Indonesian government attempts to improve connectivity and to increase regional activities in Sumatera Island through the development of Trans Sumatera Toll Road (TSTR). However, despite its benefits to local economic development in Sumatera, the project shows low feasibility due to a low amount of investment. It can be attributed from the lack of planning in the initial phase to produce a comprehensive route that considers the various potentials of the regions. Thus, this research aims to investigate alternative route planning of Trans Sumatera Toll Road particularly in this paper for Central Sumatera by studying Gross Regional Domestic Product (GRDP), population and other significant factors. This research exposes cities and districts in Riau, West Sumatera, and Jambi which potentially contribute to the regional economy. Each selected towns and districts will be integrated with the intermodal system and connected to other functions to establish the Trans Sumatera Toll Road project in Central Sumatera. Compared to existing estimation of investment from public records, this alternative route has generated a competitive cost of investment which is estimated around 118,053,400,074,696 rupiahs. The research findings are expected to become the basis to improve other similar infrastructure toll road project development.
Thermal and -γ –Ray Irradiation Effects on the Ionic Conductivity of (LiCl)x(Montmorillonite)1-x Purnama, Safei; Jahja, Aziz Khan; Sakuma, Takeshi
Makara Journal of Technology Vol. 20, No. 3
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Abstract

Compositesof montmorillonite (MMT) - lithium salts have been prepared using a simple process of powders mixing followed by heating. The powders resulting from this method are expected to beionic conductors with a high ionic conductivity characteristics. This characteristics is also further improved by employing gamma-ray irradiation technique at specified irradiation doses. The best results were obtained for the (LiCl)0.5(MMT)0.5 composite with a room temperature ionic conductivity of 2.192 mS/cm, which then increases to ~5 mS/cm after gamma irradiation at a dose of 400 kGy. This value is equivalent to the value of the ionic conductivity of current commercial rechargeable lithium battery, which is ~10 mS/cm. However the commercial battery system is still employing an unsafe organic electrolyte. By employing this lightweight,inexpensive and high-temperature resistant ceramic montmorillonite, the final result of this Research and Development workt is expected to provide an alternative solid electrolyte system for rechargeable battery which is safer and more inexpensive especially for secondary battery technology development in Indonesia.
Design of the Human Assembly Strategy in a Self-Optimizing Assembly Cell: A Case Study of Indonesians Susanto, Novie; Purwaningsih, Ratna; Kurniawati, Kharisma Panca
Makara Journal of Technology Vol. 20, No. 3
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Abstract

This paper presents a continuing study of the human cognitive aspect application in the technical systems. The last studies design a human-centered design based on the German culture. The result shows a significant difference of human performance between Germans and Indonesians. Therefore, this study examines the human cognitive model based on Indonesian culture to investigate whether the different cognitive model based on the culture aspect can improve the human performance. The study was conducted on 60 people classified by age, young (16-34 years old) and old (older than 34 years old). Participants render predictions on an assembly activity for two interim states of two different types of products which are the Builderific brick and the Pulley Release based on four types of the assembly strategy model (Reference, Combination, Human Behavior 1, and Human Behavior 2). The dependent variables are prediction time, mental workload, and predictive accuracy. The results show that the models of human assembly strategies and the products have significant influences on mental workload and predictive capability. The age variable significantly influences mental workload, performance, and prediction capabilities.

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