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
 23   24   25   26   27 
Recycling Roof Tile Waste Material for Wall Cover Tiles Mulyono, Ambar; Aryani, Silfia Mona; Lulut, Joko
Makara Journal of Technology Vol. 17, No. 3
Publisher : UI Scholars Hub

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

Abstract

Prior research on roof tile waste treatment has attempted to find the appropriate technology to reuse old roof tile waste by create wall cladding materials from it. Through exploration and experimentation, a treatment method has been discovered to transform the tile fragments into artificial stone that resembles the shape of coral. This baked clay artificial stone material is then processed as a decorative element for vertical surfaces that are not load-bearing, such as on the interior and exterior walls of a building. Before applying the fragments as wall tiles, several steps must be taken: 1) Blunting, which changes the look of tile fragments using a machine created specifically to blunt the roof-tile fragment edges, 2) Closing the pores of the blunted fragments as a finishing step that can be done with a transparent coat or a solid color of paint, 3) Planting the transformed roof-tile fragments on a prepared tile body made of concrete. In this study, the second phase is done using the method of ceramics glazing at a temperature of 700 °C. The finishing step is the strength of this product because it produces a rich color artificial pebble.
Microgrid Development Using a Grid Tie Inverter Santoso, Hartono Budi; Budiyanto, Budiyanto
Makara Journal of Technology Vol. 17, No. 3
Publisher : UI Scholars Hub

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

Abstract

The use of renewable energy sources (RES), especially photovoltaic (PV), to meet the demand of electrical energy has been getting a great deal of attention as an alternative solution to electrical energy deficit problems. RES are being applied in power systems in a variety of configurations including microgrid systems. One of the characteristics of a microgrid is capability to supplying power to grid when there is an excess power to supply local load. This research examines the chances of saving power consumption from grid using power converters grid tie inverter (GTI) in a microgrid configuration. The test is done by using a zero load and power distribution methods. Test results show grid tie GTI capable of supplying electrical power to grid up to 98% of the input power converter. In the microgrid configuration power usage from grid can be reduced up to 91%, which should be supplied from the grid to load.
The Effect Zeolite Addition in Natural Rubber Polypropylene Composite on Mechanical, Structure, and Thermal Characteristics Bukit, Nurdin; Frida, Erna
Makara Journal of Technology Vol. 17, No. 3
Publisher : UI Scholars Hub

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

Abstract

This study was conducted to determine the effect of zeolite as filler on mechanical properties, and thermal structure blends of natural rubber and polypropylene (NR/PP). In this study, NR/PP/PP-g-MA blends was filled uncalcined zeolite and calcined zeolite at different weight percent of the 2, 4, and 6%. Samples were characterized to determine the tensile strength, fracture elongation and Young's modulus. Structure of the samples was investigated using XRD method and thermal characteristics were analyzed using DTA/TGA technique. The results obtained for tensile strength showed a significant influence with the addition zeolite of the NR/PP blends at 2% by weight of the composition (8 MPa) and decreased with increasing zeolite composition uncalcined zeolite or calcined zeolite. At 2% to 6% by weight of an increase in Young's modulus, for which uncalcined zeolite function more effectively than the calcined zeolite. On the other hand, the addition of uncalcined zeolite and calcined zeolite did not result in decreased fracture elongation. The XRD analysis zeolite indicate the existence of amorphous phase and crystalline mineral type mordenite (CaAl2Si10O24.7 H2O). In general, cristality of samples filled with calcined zeolite slightly higher than the uncalcined zeolite at the same amount and intercalation occurs between the zeolite matrix NR/PP. Thermal analysis showed that the samples are filled with calcined zeolite has a thermal resistance higher than the uncalcined zeolite, the melting point NR/PP 165.0 °C with the addition of 6 wt% zeolite melting point to 186.7 °C.
Synthesis of Tungsten Oxide Nanowires onto ITO Glass Using T-CVD Abuzairi, Tomy; Huang, Bohr-Ran; Lin, Tzu-Ching
Makara Journal of Technology Vol. 17, No. 3
Publisher : UI Scholars Hub

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

Abstract

Tungsten oxide is an n-type semiconductor with interesting physical and chemical properties that make it suitable for various technological applications. Tungsten oxide nanowires were synthesized not only at low temperature but also without the use of any catalysts. The tungsten oxide nanowires were synthesized at 550 °C with tungsten layers onto the ITO glass using thermal chemical vapor deposition (T-CVD). The SEM image shows that the tungsten oxide nanowires are effectively grown with the 200 nm tungsten film. The Raman spectra shoulder at ~690 cm-1 proves the synthesized of tungsten oxide nanowires.
Surface Treatment of Fly Ash for Improving the Tensile Strength of Fly Ash/Unsaturated Polyester Composites Sugiman, Sugiman; Setyawan, Paryanto Dwi
Makara Journal of Technology Vol. 17, No. 3
Publisher : UI Scholars Hub

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

Abstract

The paper presents the surface treatment of fly ashes using acid and alkali solution on the tensile strength of the fly ash/unsaturated polyester (UP) composites. Sulfuric acid (H2SO4), hydrofluoric acid (HF) and sodium hydroxide (NaOH) solution with concentration of 0%, 5%, 10%, 15%, and 20% (by weight) were used for surface treatment of fly ashes. Generally, the tensile strength of the treated fly-ash/UP composites shows a significant increase compared to the untreated fly ash. Of all surface treatments studied, the optimum tensile strength was obtained at a concentration of 10%. At this concentration, at a fly ash content of 30% (weight), the surface treatment using NaOH gave the highest tensile strength, approximately 18.69 MPa, or increased about 91% compared to the untreated fly ash. The morphology of fracture surfaces were evaluated using a scanning electron microscope (SEM). The fracture surfaces of the treated fly ash composite were rougher than that of the untreated fly ash indicating the improvement of the fly ashes-UP interaction.
Semiconductor Thermal Neutron Detector Aoki, Toru; Miyake, Aki; Nakano, Takayuki; Koike, Akifumi; Morii, Hisashi; Mimura, Hidenori
Makara Journal of Technology Vol. 17, No. 3
Publisher : UI Scholars Hub

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

Abstract

The CdTe and GaN detector with a Gd converter have been developed and investigated as a neutron detector for neutron imaging. The fabricated Gd/CdTe detector with the 25 mm thick Gd was designed on the basis of simulation results of thermal neutron detection efficiency and spatial resolution. The Gd/CdTe detector shows the detection of neutron capture gamma ray emission in the 155Gd(n, g)156Gd, 157Gd(n, g)158Gd and 113Cd(n, g)114Cd reactions and characteristic X-ray emissions due to conversion-electrons generated inside the Gd film. The observed efficient thermal neutron detection with the Gd/CdTe detector shows its promise in neutron radiography application. Moreover, a BGaN detector has also investigated to separate neutron signal from gamma-ray clearly.
Radiation Characteristics of a Planar Strip Dipole Antenna and a Slot Dipole Antenna for THz Applications Apriono, Catur; Rahardjo, Eko Tjipto
Makara Journal of Technology Vol. 17, No. 3
Publisher : UI Scholars Hub

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

Abstract

The development of a THz system often requires a device that is used to radiate or detect THz waves. One way to fulfill this requirement is to use an antenna. Therefore, we need to consider the radiation characteristics of an antenna working in the THz region. In this paper, we present simulation study of two dipole antennas, i.e. a planar strip dipole antenna and a slot dipole antenna. The simulation results show that a planar strip dipole antenna has a better radiation efficiency (more than 95%) compared to the slot dipole. It also shows that an efficiency of more than 98% can be achieved when using silicon dielectric substrate. Furthermore, a return loss characteristic of 38,752 dB can be achieved by using a silicon dielectric substrate and a metal layer of Au for the planar slot dipole antenna.
The Effect of Pressing Temperature and Time on the Quality of Particle Board Made from Jatropha Fruit Hulls Treated in Acidic Condition Iswanto, Apri Heri; Febrianto, Fauzi; Hadi, Yusuf Sudo; Ruhendi, Surdiding; Hermawan, Dede
Makara Journal of Technology Vol. 17, No. 3
Publisher : UI Scholars Hub

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

Abstract

The high of pH of jatropha fruit hulls causes the negative properties of particleboard made from this material. Adjusting the particle acidity and pressing conditions (temperature and time) is among the technical modifications available to improve this particleboard’s properties. Particle acidity has been adjusted in a previous research project, and immersing the particles in acetic acid was found to be the best treatment in this preliminary research. In order to improve the particleboard’s properties, an experiment was conducted to determine the best pressing temperature and time. The objective of the research was to evaluate the influence of pressing temperature and time on the physical and mechanical properties of the board. Jatropha fruit hulls were immersed in 1% acetic acid solution for 24 hours. UF resin was used as the adhesive in the amount of 10%. The pressing temperatures and times used in this research were 110 °C, 120 °C, and 130 °C for 8 and 10 minutes, respectively. The particleboards were tested to determine their physical and mechanical properties according to JIS A 5908-2003. The result showed that pressing at 130 °C for 10 minutes resulted in the best physical and mechanical properties. Increasing the pressing temperature at a constant time or increasing the pressing time at a constant temperature caused the particleboard to exhibit decreased water absorption. The thickness swelling and modulus of elasticity (MOE) of the particleboard did not fulfil JIS A 5908-2003.
Synthesis and Characterization of Soy-Based Polyurethane Foam with Utilization of Ethylene Glycol in Polyol Firdaus, Flora Elvistia
Makara Journal of Technology Vol. 18, No. 1
Publisher : UI Scholars Hub

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

Abstract

The use of vegetable oils on replacing petroleum has attracted attention of many researchers. The chemical structure of vegetable oils are different from petrochemicals, so the structure of soybean oil has to be chemically modified through its unsaturated fatty acid chain in triglyceride. A two step process was conducted for the preparation of soy-polyol in designated temperatures; 50 °C, 60 °C, and 70 °C. Ethylene glycol (EG) as co-reagent was taking part in soy-polyol synthesis, and the soy-polyol was used as a sole polyol for polyurethane synthesis. Referred to the previous study, the existence of EG in polyurethane synthesis can improved physical properties of polyurethane foam. The aim of this research is using soy-derived polyol for petro-polyol replacement aligned with drop-off of petro-derived reagent; EG. One step process was applied for the foam synthesis. The ingredients for foam synthesis; soy-polyol, Toluene diisocyanate (TDI): a mixture of 2.4 and 2.6 isomers in ratio of 80:20 (TDI T-80), surfactant, and distilled water. The synergize of stoichiometry ratio of co-reagent EG to soy-epoxide with best temperature, with the absence of EG in polyurethane formula can produce an ultimate property of polyurethane foam.
Dynamic Characteristic Identification of Seismic-Excited Multi-Story Buildings through Response-Only Technique Budipriyanto, Agung; Suprobo, Priyo
Makara Journal of Technology Vol. 18, No. 1
Publisher : UI Scholars Hub

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

Abstract

Identifying dynamic characteristics of civil engineering structures is still a challenging task. It intends to assess behavior of the structures under time-dependent loads. This paper discusses a methodology suitable for identifying the characteristics of multi-story buildings using only their measured response under earthquake ground excitations. Appropriateness of technique used for structural identification was corroborated through coherence of the structure’s responses. The methodology was applied for identifying the characteristics of 14-story and 20-story office buildings located in a high seismic region. Responses of these two buildings recorded during three different seismic ground motions were investigated. The buildings’ response spectral densities and singular values were computed and utilized to identify their dynamic characteristics, viz. modal frequencies, damping factors, and mode types such as bending or torsion mode. Results of this study were validated through comparisons with the results reported using different structural identification techniques. It indicated that the methodology implemented in this study was capable of identifying the dynamic characteristics of multi-story buildings using responses under seismic ground motions.

Page 25 of 49 | Total Record : 485

 23   24   25   26   27 

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