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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 9 Documents
Search results for , issue "Vol. 17, No. 1" : 9 Documents clear
Electromagnetic Simulation for THz Antenna-Coupled Microbolometers Operated at Room Temperature Aoki, Makoto; Takeda, Masanori; Hiromoto, Norihisa
Makara Journal of Technology Vol. 17, No. 1
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Abstract

Room-temperature terahertz (THz) detectors with higher performance are necessary for utilizing the THz wave in various sensing, spectroscopy and imaging, but even the best ones in the present are still insufficient for the practical applications. This issue is essential especially in the region around 1 THz at which there exists a large technology gap between microwave and middle-infrared. Therefore, we study to develop an antenna-coupled microbolometer to achieve a high-performance THz detector operated at a room-temperature for sensing at around 1 THz frequency wave. In this paper, we present several important features and results obtained from electromagnetic simulations, which help to design a structure of the antenna and heater to absorb efficiently the power of THz wave.
Analysis of Hole Lifetime in SOI MOSFET Single-Photon Detector Putranto, Dedy Septono Catur; Du, Wei; Satoh, Hiroaki; Ono, Atsushi; Priambodo, Purnomo Sidi; Hartanto, Djoko; Inokawa, Hiroshi
Makara Journal of Technology Vol. 17, No. 1
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Abstract

Hole lifetime in the silicon-on-insulator (SOI) metal-oxide-semiconductor field-effect transistor (MOSFET) singlephoton detector was evaluated by the analysis of drain current histograms for different light intensities and substrate voltages. It was found that the peaks in the histogram corresponding to the larger number of stored holes grew as the gate bias decreased. This was attributed not to the increased light absorption efficiency or collection efficiency of the photo-generated holes, but to the prolonged hole lifetime presumably caused by the higher transverse electric field inside the body of SOI MOSFET.
Biodiesel Reactor Design with Glycerol Separation to Increase Biodiesel Production Yield Rahmat, Budy; Setiasih, Imas Siti; Kastaman, Roni
Makara Journal of Technology Vol. 17, No. 1
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Abstract

The study consisted of reactor design used for transesterification process, effect of glycerol separation on transesterification reaction, determination of biodiesel quality, and mass balance analysis. The reactor was designed by integrating circulated pump/stirrer, static mixer, and sprayer that intensify the reaction in the outer tank reactor. The objective was to reduce the use of methanol in excess and to shorten the processing time. The results showed that the reactor that applied the glycerol separation was able to compensate for the decreased use of the reactant methanol from 6:1 to 5:1 molar ratio, and changed the mass balance in the product, including: (i) the increase of biodiesel production from 42.37% to 49.34%, and (ii) the reduction of methanol in excess from 42.37% to 32.89%. The results suggested that the efficiency of biodiesel production could be increased with the glycerol separation engineering.
Growth of CrSi2 Nanostructures Using CrCl2 Powder on Si Substrates Li, Wen; Erchao, Meng; Matsushita, Tomoji; Oda, Shingo; Ishikawa, Daisuke; Nakane, Kaito; Tatsuoka, Hirokazu
Makara Journal of Technology Vol. 17, No. 1
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Abstract

Chromium disilicide (CrSi2) nanostructures were grown by the exposure of Si (111) substrates to CrCl2 vapor in an argon gas flow at atmospheric pressure without using any metal catalyst. Dependence of the growth condition on the structural property was investigated. Hexagonal-shaped CrSi2 microrods were grown at 750 °C with 0.05 g of CrCl2. As the quantity of CrCl2 increased to 0.1 g, the bundle of CrSi2 nanowires with microrods and web-liked CrSi2 nanostructure with turning angles were grown at 750 °C and 700 °C, respectively. The preliminary discussion on the growth mechanism of CrSi2 micro- and nanostructures was carried out.
Development of Seebeck-Coefficient Measurement Systems Using Kelvin-Probe Force Microscopy Miwa, Kazutoshi; Salleh, Faiz; Ikeda, Hiroya
Makara Journal of Technology Vol. 17, No. 1
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Abstract

Thermoelectric device is investigated by a number of researchers in order to enhance the thermoelectric efficiency. It is known that the efficiency can be improved by quantum effect. However, it is difficult to measure the thermoelectric characteristics of nanometer-scale structures. Thus a new measurement method is expected to be developed. We propose to apply Kelvin-probe force microscopy (KFM) to characterization of thermoelectric materials. KFM can locally observe surface potential of Fermi energy of a sample without touching the sample surface. In the present paper, we estimate the Seebeck coefficient of thin Si-on-insulator layers using KFM.
Performance Optimization of Microbial Fuel Cell (MFC) Using Lactobacillus bulgaricus Arbianti, Rita; Utami, Tania Surya; Hermansyah, Heri; Novitasari, Deni; Kristin, Ester; Trisnawati, Ira
Makara Journal of Technology Vol. 17, No. 1
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Abstract

Electrical energy needs in Indonesia are expected to continue to rise. The use of petroleum as a source of energy still dominates, although oil reserves in Indonesia are increasingly being depleted. Therefore, there is a need to develop alternative sources of sustainable energy, such as microbial fuel cell (MFC). In this study, Lactobacillus bulgaricus was used as an electricity producer in a dual-chamber MFC reactor. We investigated the maximum electrical energy by varying the bacterial optical density (OD), the operational time of MFC, the reactor volume, the electrolyte solution, and the configuration of MFC reactor. In this study, the maximum electrical energy (201.8 mW/m2) was generated at an OD of 0.5 in an MFC reactor series using potassium permanganate as the electrolyte solution.
Recognition System of Indonesia Sign Language based on Sensor and Artificial Neural Network Supriyati, Endang; Iqbal, Mohammad
Makara Journal of Technology Vol. 17, No. 1
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Abstract

Sign language as a kind of gestures is one of the most natural ways of communication for most people in deaf community. The aim of the sign language recognition is to provide a translation for sign gestures into meaningful text or speech so that communication between deaf and hearing society can easily be made. In this research, the Indonesian sign language recognition system based on flex sensors and an accelerometer is developed. This recognition system uses a sensory glove to capture data. The sensor data that are processed into feature vector are the 5-fingers bending and the palm acceleration when performing the sign language. The most important part of the recognition system is a feature extraction. In this research, histogram is used as feature extraction. The extracted features are used as data training and data testing for Adaptive Neighborhood based Modified Backpropagation (ANMBP). The system is implemented and tested using a data set of 1000 samples of 50 Indonesia sign, 20 samples for each sign. Among these 500 data were used as the training data, and the remaining 500 data were used as the testing data. The system obtains the recognition rate of 91.60% in offline mode.
Biological Pretreatment of Oil Palm Frond Fiber Using White-Rot Fungi for Enzymatic Saccharification Hermiati, Euis; Anita, Sita Heris; Risanto, Lucky; Styarini, Dyah; Sudiyani, Yanni; Hanafi, Achmad; Abimanyu, Haznan
Makara Journal of Technology Vol. 17, No. 1
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Abstract

Oil palm frond is one type of lignocellulosic biomass abundantly and daily available in Indonesia. It contains cellulose which can be converted to glucose, and further processed to produce different kinds of value –added products. The aim of this research is to study the effects of biological pretreatment of oil palm frond (OPF) fiber using Phanerochaete chrysosporium and Trametes versicolor on the enzymatic saccharification of the biomass. The OPF fiber (40-60 mesh sizes) was inoculated with cultures of the two fungi and incubated at 27 °C for 4 weeks. The samples were taken after 1, 2, 3, and 4 weeks of incubation. Chemical components of the biomass after pretreatment were analyzed. The saccharification of the pretreated samples using cellulase and β-glucosidase was performed in a water bath shaker at 50 °C for 48 hours. The concentration of reducing sugar increased with increasing of incubation time, either in those pretreated with culture of P. chrysosporium or with T. versicolor. Pretreatment of OPF fiber using single culture of T. versicolor for 4 weeks gave the highest reducing sugar yield (12.61% of dry biomass).
Agricultural Drought Pattern in West Java Using Thermal Vegetation Index from Modis-Terra Satellite Daruati, Dini; Rahmatulloh, Rahmatulloh; Purwadhi, Sri Hardiyanti
Makara Journal of Technology Vol. 17, No. 1
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This study examines agricultural drought paddy fields in West Java. The aims of this research are to know the pattern and distribution of paddy field drought in West Java and the correlation between drought and the physical characteristics. The agricultural drought is obtained from TVI (Thermal Vegetation Index) model. TVI is derived from MODIS Terra satellite image, which is the ratio between the LST (Land Surface Temperature) and EVI (Enhanced Vegetation Index). Physical factors studied are rainfall, l slope, geomorphology, soil drainage, and irrigation areas. The most severe drought occurred in September 2006 because of El Nino, covering 806,564 ha, and distributed in almost all West Java Province while the lowest occurred in September 2010 because of La Nina, covering 101,959 ha, and mostly distributed in Subang and Indramayu district. Spatial distribution of drought in 2000-2011 has the same pattern. At the start of the dry season (May) drought occurred in the north (along the coast) then expanded to the east / south in the middle of the dry season (July-August) and then increased further to the west at the end of the dry season (September). Incidence of drought has correlation with the physical condition of the area, but the most influential is the rainfall based on Chi-square test.

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