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Articles 121 - 150 of 431
Full-Text Articles in Civil Engineering
Characterization And Utilization Of Calcium Oxide (Cao) Thermally Decomposed From Fish Bones As A Catalyst In The Production Of Biodiesel From Waste Cooking Oil, Aldes Lesbani, Sabat Okta Ceria Sitompul, Risfidian Mohadi, Nurlisa Hidayati
Characterization And Utilization Of Calcium Oxide (Cao) Thermally Decomposed From Fish Bones As A Catalyst In The Production Of Biodiesel From Waste Cooking Oil, Aldes Lesbani, Sabat Okta Ceria Sitompul, Risfidian Mohadi, Nurlisa Hidayati
Makara Journal of Technology
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 …
Thermoeconomic Optimization Of Cascade Refrigeration System Using Mixed Carbon Dioxide And Hydrocarbons At Low Temperature Circuit, Nasruddin Nasruddin, Arnas Arnas, Ahmad Faqih, Niccolo Giannetti
Thermoeconomic Optimization Of Cascade Refrigeration System Using Mixed Carbon Dioxide And Hydrocarbons At Low Temperature Circuit, Nasruddin Nasruddin, Arnas Arnas, Ahmad Faqih, Niccolo Giannetti
Makara Journal of Technology
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 …
Developing Road Infrastructure Route Planning: Increasing Feasibility Of Toll Road Project, Mohammed Ali Berawi, Teuku Yuri Zagloel, Perdana Miraj, Abdur Rohim Boy Berawi, Wellsi Titaheluw, Saipol Bari Bin Abd Karim
Developing Road Infrastructure Route Planning: Increasing Feasibility Of Toll Road Project, Mohammed Ali Berawi, Teuku Yuri Zagloel, Perdana Miraj, Abdur Rohim Boy Berawi, Wellsi Titaheluw, Saipol Bari Bin Abd Karim
Makara Journal of Technology
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 …
Thermal And -Γ –Ray Irradiation Effects On The Ionic Conductivity Of (Licl)X(Montmorillonite)1-X, Safei Purnama, Aziz Khan Jahja, Takeshi Sakuma
Thermal And -Γ –Ray Irradiation Effects On The Ionic Conductivity Of (Licl)X(Montmorillonite)1-X, Safei Purnama, Aziz Khan Jahja, Takeshi Sakuma
Makara Journal of Technology
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 …
Study On Oil Palm Fresh Fruit Bunch Bruise In Harvesting And Transportation To Quality, Andreas Wahyu Krisdiarto, Lilik Sutiarso
Study On Oil Palm Fresh Fruit Bunch Bruise In Harvesting And Transportation To Quality, Andreas Wahyu Krisdiarto, Lilik Sutiarso
Makara Journal of Technology
There are losses of production due to oil palm field’s material handling. Activities that may raise the losses are harvesting and transportation, which may cause bruise and damage to fruit. This research was aimed to learn the bruise of fresh fruit bunch (FFB) phenomenon in harvesting and transportation. Method used in this research was measuring the bruise area resulted by FFB falling when harvested, loading (throwing up) FFB to truck bin, and transporting using truck. These data, coupled with weight of bruised fruit, were calculated to get FFB bruise index. Each FFB bruise index is related to potential free fatty …
Automatic Arrhythmia Beat Detection: Algorithm, System, And Implementation, Wisnu Jatmiko, I Md. Agus Setiawan, Muhammad Ali Akbar, Muhammad Eka Suryana, Yulistiyan Wardhana, Muhammad Febrian Rachmadi
Automatic Arrhythmia Beat Detection: Algorithm, System, And Implementation, Wisnu Jatmiko, I Md. Agus Setiawan, Muhammad Ali Akbar, Muhammad Eka Suryana, Yulistiyan Wardhana, Muhammad Febrian Rachmadi
Makara Journal of Technology
Cardiac disease is one of the major causes of death in the world. Early diagnose of the symptoms depends on abnormality on heart beat pattern, known as Arrhythmia. A novel fuzzy neuro generalized learning vector quantization for automatic Arrhythmia heart beat classification is proposed. The algorithm is an extension from the GLVQ algorithm that employs a fuzzy logic concept as the discriminant function in order to develop a robust algorithm and improve the classification performance. The algorithm is tested against MIT-BIH arrhythmia database to measure the performance. Based on the experiment result, FN-GLVQ is able to increase the accuracy of …
Optimization Of Electricity Generation Schemes In The Java-Bali Grid System With Co2 Reduction Consideration, Farizal Farizal, Wenty Eka Septia, Amar Rachman, Nasruddin Nasruddin, Teuku Meurah Indra Mahlia
Optimization Of Electricity Generation Schemes In The Java-Bali Grid System With Co2 Reduction Consideration, Farizal Farizal, Wenty Eka Septia, Amar Rachman, Nasruddin Nasruddin, Teuku Meurah Indra Mahlia
Makara Journal of Technology
This research considers the problem of reducing CO2 emissions from the Java-Bali power grid system that consists of a variety of power-generating plants: coal-fired, natural gas, oil, and renewable energy (PV, geothermal, hydroelectric, wind, and landfill gas). The problem is formulated as linear programming and solved using LINGO 10. The model was developed for a nation to meet a specified CO2 emission target. Two carbon dioxide mitigation options are considered in this study, i.e. fuel balancing and fuel switching. In order to reduce the CO2 emissions by 26% in 2021, State Electric Supply Company (PLN) has to generate up to …
Apparent Porosity And Compressive Strength Of Heat-Treated Clay/Iron Sand/Rice Husk Ash Composites Over A Range Of Sintering Temperatures, M. Nizar Machmud, Zulkarnain Jalil, Mochammad Afifuddin
Apparent Porosity And Compressive Strength Of Heat-Treated Clay/Iron Sand/Rice Husk Ash Composites Over A Range Of Sintering Temperatures, M. Nizar Machmud, Zulkarnain Jalil, Mochammad Afifuddin
Makara Journal of Technology
Novel composites of clay/iron sand/rice husk ash (RHA) have been developed. Electric furnace was used to perform heat treatment on the composites to study the effect of sintering temperature on their apparent porosity and compressive strength. Two types of RHA with different bulk density were prepared to gain an understanding of the influence of apparent porosity on compressive strength of the heat-treated composites over a range of sintering temperatures. Heattreated composites, made of clay/iron sand and clay/RHA, were also prepared as a referenced material. X-ray diffraction (XRD) analysis was further performed to comprehensively discuss the role of iron sand on …
The Effect Of Irradiation Of Fe And Ar Ion On The Surface Morphology Of Diamond Thin Film Related To The Magnetoresistance Property, Salim Mustofa, Setyo Purwanto, Kenji Mishima
The Effect Of Irradiation Of Fe And Ar Ion On The Surface Morphology Of Diamond Thin Film Related To The Magnetoresistance Property, Salim Mustofa, Setyo Purwanto, Kenji Mishima
Makara Journal of Technology
The irradiation of Fe and Ar ion was applied on the surface of diamond/Si thin film to know its effect on the morphology of thin film.The magnetoresistance property was also studied. Ion irradiation treatment using Fe ion followed by argon ion at the energy of 70keV and a dose of 1 x 1015 ion/cm2 have been conducted on the surface of two types of thin film, diamond/Si (111) and diamond/Si (100). Both thin films were made by using a CVD method, and the thickness of the thin film is 1000-nm. From simulations using the software called Stopping and Range of …
Use Of Green Mussel Shell As A Desulfurizer In The Blending Of Low Rank Coal-Biomass Briquette Combustion, Mahidin Mahidin, Asri Gani, M. Reza Hani, Muhammad Syukur, Hamdani Hamdani, Khairil Khairil, Samsul Rizal, Abdul Hadi, T.M.I. Mahlia
Use Of Green Mussel Shell As A Desulfurizer In The Blending Of Low Rank Coal-Biomass Briquette Combustion, Mahidin Mahidin, Asri Gani, M. Reza Hani, Muhammad Syukur, Hamdani Hamdani, Khairil Khairil, Samsul Rizal, Abdul Hadi, T.M.I. Mahlia
Makara Journal of Technology
Calcium oxide-based material is available abundantly and naturally. A potential resource of that material comes from marine mollusk shell such as clams, scallops, mussels, oysters, winkles and nerites. The CaO-based material has exhibited a good performance as the desulfurizer or adsorbent in coal combustion in order to reduce SO2 emission. In this study, pulverized green mussel shell, without calcination, was utilized as the desulfurizer in the briquette produced from a mixture of low rank coal and palm kernel shell (PKS), also known as bio-briquette. The ratio of coal to PKS in the briquette was 90:10 (wt/wt). The influence of green …
The Knowledge-Based Analysis On Medium Resolution Images Of Remote Sensing To Extraction Information Land Use Type Scs-Cn, The Case Study On Grompol Watershed, Puguh Dwi Raharjo, Totok Gunawan, Mohammad Pramono Hadi
The Knowledge-Based Analysis On Medium Resolution Images Of Remote Sensing To Extraction Information Land Use Type Scs-Cn, The Case Study On Grompol Watershed, Puguh Dwi Raharjo, Totok Gunawan, Mohammad Pramono Hadi
Makara Journal of Technology
Remote sensing imagery Landsat-8 is one image that has a good temporal resolution; in addition to the availability of data, this image can be obtained free of charge. Land cover type SCS-CN is part of a unit of land that affects runoff. The use of medium resolution imagery in reducing the SCS-CN land use type is considered relatively difficult, and it yields less good accuracy. Limitations on multispectral classification only rely on facts derived from spectral reflection, so that the two data are the same since different characteristic results are not so good. This study aims to determine the accuracy …
Sugarcane Bagasse As A Carrier For The Immobilization Of Saccharomyces Cerevisiaein Bioethanol Production, Sita Heris Anita, Wibowo Mangunwardoyo, Yopi Yopi
Sugarcane Bagasse As A Carrier For The Immobilization Of Saccharomyces Cerevisiaein Bioethanol Production, Sita Heris Anita, Wibowo Mangunwardoyo, Yopi Yopi
Makara Journal of Technology
Sugarcane bagasse was used as a carrier to immobilize Saccharomyces cerevisiae in bioethanol production. This research aims to study the potential use of sugarcane bagasse as an alternative carrier for cell immobilization and improvement in the production process of cell immobilization in bagasse. The results showed that the physical characteristics of sugarcane bagasse as a carrier were water content (7.77 ± 0.35%), water retention (4.80 ± 0.44 g/g), water absorption index (8.58 ± 0.22 g/g), and lignin content (24.40 ± 1.52 %). Determination of cell retention was performed in an inoculum volume of 50 mL yeast suspension with various carrier …
A Comparison Of American, Norwegian, And Russian Standards In Calculating The Wall Thickness Of Submarine Gas Pipeline, Cindy Dianita, Tatyana Vladimirovna Dmitrieva
A Comparison Of American, Norwegian, And Russian Standards In Calculating The Wall Thickness Of Submarine Gas Pipeline, Cindy Dianita, Tatyana Vladimirovna Dmitrieva
Makara Journal of Technology
One of the key issues in the pipeline design is wall thickness calculation. This paper highlights a comparison of wall thickness calculation methods of submarine gas pipeline based on Norwegian Standard (DNV-OS-F101), Indonesian Standard SNI 3474 which refers to American Standard (ASME B31.8), and Russian Standard (VN39-1.9-005-98). A calculation of wall thickness for a submarine gas pipeline in Indonesia (pressure 12 MPa, external diameter 668 mm) gives the results of 18.2 mm (VN39-1.9-005-98), 16 mm (ASME B31.8), and 13.5 mm (DNV-OS-F101).The design formula of hoop stress due to internal pressure is interpreted in different ways for every standard. Only Norwegian …
Texture Analysis Using The Neutron Diffraction Method On The Non Standardized Austenitic Steel Process By Machining,Annealing, And Rolling, Tri Hardi Priyanto, Parikin Parikin, Meijuan Li
Texture Analysis Using The Neutron Diffraction Method On The Non Standardized Austenitic Steel Process By Machining,Annealing, And Rolling, Tri Hardi Priyanto, Parikin Parikin, Meijuan Li
Makara Journal of Technology
Austenitic steel is one type of stainless steel which is widely used in the industry. Many studies on austenitic stainless steel have been performed to determine the physical properties using various types of equipment and methods. In this study, the neutron diffraction method is used to characterize the materials which have been made from minerals extracted from the mines in Indonesia. The materials consist of a granular ferro-scrap, nickel, ferro-chrome, ferro-manganese, and ferro-silicon added with a little titanium. Characterization of the materials was carried out in three processes, namely: machining, annealing, and rolling. Experimental results obtained from the machining process …
Thermal Properties, Crystallinity, And Oxygen Permeability Of Na-Montmorillonite Reinforced Plasticized Poly(Lactic Acid) Film, Kurniawan Yuniarto, Yohanes Aris Purwanto, Setyo Purwanto, Bruce A. Welt, Hadi Karia Purwadaria, Titi Candra Sunarti
Thermal Properties, Crystallinity, And Oxygen Permeability Of Na-Montmorillonite Reinforced Plasticized Poly(Lactic Acid) Film, Kurniawan Yuniarto, Yohanes Aris Purwanto, Setyo Purwanto, Bruce A. Welt, Hadi Karia Purwadaria, Titi Candra Sunarti
Makara Journal of Technology
Introducing unmodified organically clay/Na-montmorillonite (Na-MMT) was applied into plasticized poly(lactic acid) PLA to produce film composites by direct casting. Film composite structure, the crystallinity degree and form, and thermal properties were carried out using X-ray diffraction and differential scanning calorimetry. The effect of Na- MMT to the tortuous path and the crystallinity degree in the plasticized film composites were calculated in oxygen barrier properties. Chromatogram film composites resulted in an intercalated structure that showed peak diffraction angle shift at about 0.2o. Then, a peak diffraction pattern was indicated in α-form crystal structure. Plasticized PLA has a crystallinity degree at 34%, …
Residual Strength Analysisof Asymmetrically Damaged Ship Hull Girderusing Beam Finite Element Method, Muhammad Zubair Muis Alie
Residual Strength Analysisof Asymmetrically Damaged Ship Hull Girderusing Beam Finite Element Method, Muhammad Zubair Muis Alie
Makara Journal of Technology
The objective of the present study is to analyze the residual strength of asymmetrically damaged ship hull girder under longitudinal bending. Beam Finite Element Method is used for the assessment of the residual strength of two single hull bulk carriers (Ship B1 and Ship B4) and a three-cargo-hold model of a single-side Panamax Bulk Carrier in hogging and sagging conditions. The Smith’s method is adopted and implemented into Beam Finite Element Method. An efficient solution procedure is applied; i.e. by assuming the cross section remains plane, the vertical bending moment is applied to the cross section and three-cargo-hold model. As …
Maneuverability Of Ships With Small Draught In Steady Wind, Daeng Paroka, Andi Haris Muhammad, Syamsul Asri
Maneuverability Of Ships With Small Draught In Steady Wind, Daeng Paroka, Andi Haris Muhammad, Syamsul Asri
Makara Journal of Technology
Wind force and moment may force a ship to drastically decrease its speed and use a large drift angle as well as a large rudder angle in order to maintain its course. Ships with a small draught might have more risk in maneuvering to its point of view compared with a ship with a larger draught. This paper discusses maneuverability of a ship with a small draught in steady wind. The effect of wind on ship speed, drift angle, and rudder angle are investigated in a steady state condition. Five different ratios of wind velocity to ship speed from 1.0 …
Discrete Power Control In Heterogenous Networks, Yuanyuan Wang, Wibowo Hardjawana, Branka Vucetic
Discrete Power Control In Heterogenous Networks, Yuanyuan Wang, Wibowo Hardjawana, Branka Vucetic
Makara Journal of Technology
In heterogeneous networks (HetNets) where femtocell base stations (FBSs) are deployed within the radio coverage of macrocell base stations (MBSs) to increase network capacity, co-channel interference limits overall system performance with universal frequency reuse. This paper investigates new distributed downlink discrete power control scheme for FBSs in HetNets with FBSs cooperation. The objective of the proposed power control scheme is to maximize the number of simultaneous FBSs transmissions in a single transmission wireless channel where each FBS is allowed to transmit only if the signal-to-interference-noise ratio (SINR) requirements for both FBSs and MBS users are satisfied. We apply a stochastic …
Multi-Project Scheduling Cost Optimization In A Machine Manufacturer Engineer-To-Order, Farizal Farizal, Amar Rachman, Tifani Tandean, Sumarsono Sudarto, Katsuhiko Takahashi
Multi-Project Scheduling Cost Optimization In A Machine Manufacturer Engineer-To-Order, Farizal Farizal, Amar Rachman, Tifani Tandean, Sumarsono Sudarto, Katsuhiko Takahashi
Makara Journal of Technology
This paper discusses the utilization of mixed integer linear programming (MILP) model to optimize cost for multiproject scheduling in a machine maker company. The objective is to minimize total project’s penalty cost and labor cost. The model formulated shows how to achieve the objective i.e. whether to use outsourcing or overtime to finish all projects. The model of multi-project scheduling was solved by Branch & Bound algorithm coded in Lingo 14.0 software. The case study shows that if a company wants to minimize lateness, it should use overtime instead of outsourcing, which minimize total lateness of projects by 144 days …
Analysis Of Arm Movement Prediction By Using The Electroencephalography Signal, Reza Darmakusuma, Ary Setijadi Prihatmanto, Adi Indrayanto, Tati Latifah Mengko, Lidwina Ayu Andarini, Achmad Furqon Idrus
Analysis Of Arm Movement Prediction By Using The Electroencephalography Signal, Reza Darmakusuma, Ary Setijadi Prihatmanto, Adi Indrayanto, Tati Latifah Mengko, Lidwina Ayu Andarini, Achmad Furqon Idrus
Makara Journal of Technology
Various technological approaches have been developed in order to help those people who are unfortunate enough to be afflicted with different types of paralysis which limit them in performing their daily life activities independently. One of the proposed technologies is the Brain-Computer Interface (BCI). The BCI system uses electroencephalography (EEG) which is generated by the subject’s mental activity as input, and converts it into commands. Some previous experiments have shown the capability of the BCI system to predict the movement intention before the actual movement is onset. Thus research has predicted the movement by discriminating between data in the “rest” …
Calibration Of Numerical Model For Shoreline Change Prediction Using Satellite Imagery Data, Sigit Sutikno, Keisuke Murakami, Dwi Puspo Handoyo, Manyuk Fauzi
Calibration Of Numerical Model For Shoreline Change Prediction Using Satellite Imagery Data, Sigit Sutikno, Keisuke Murakami, Dwi Puspo Handoyo, Manyuk Fauzi
Makara Journal of Technology
This paper presents a method for calibration of numerical model for shoreline change prediction using satellite imagery data in muddy beach. Tanjung Motong beach, a muddy beach that is suffered high abrasion in Rangsang Island, Riau province, Indonesia was picked as study area. The primary numerical modeling tool used in this research was GENESIS (GENEralized Model for Simulating Shoreline change), which has been successfully applied in many case studies of shoreline change phenomena on a sandy beach.The model was calibrated using two extracted coastlines satellite imagery data, such as Landsat-5 TM and Landsat-8 OLI/TIRS. The extracted coastline data were analyzed …
Independency Of Elasticity On Residual Stress Of Room Temperature Rolled Stainless Steel 304 Plates For Structure Materials, Parikin Parikin, David Allen
Independency Of Elasticity On Residual Stress Of Room Temperature Rolled Stainless Steel 304 Plates For Structure Materials, Parikin Parikin, David Allen
Makara Journal of Technology
Mechanical strengths of materials are widely expected in general constructions of any building. These properties depend on its formation (cold/hot forming) during fabrication. This research was carried out on cold-rolled stainless steel (SS) 304 plates, which were deformed to 0, 34, 84, and 152% reduction in thickness. The tests were conducted using Vickers method. Ultra micro indentation system (UMIS) 2000 was used to determine the mechanical properties of the material, i.e.: hardness, modulus elasticity, and residual stresses. The microstructures showed lengthening outcropping due to stress corrosion cracking for all specimens. It was found that the tensile residual stress in a …
Effect Of Fly Ash Fortification In The Manufacture Process Of Making Concrete Towards Characteristics Of Concrete In Sulfuric Acid Solution, Asep Handaya Saputra, Muhammad Shohibi, Masatoshi Kubouchi
Effect Of Fly Ash Fortification In The Manufacture Process Of Making Concrete Towards Characteristics Of Concrete In Sulfuric Acid Solution, Asep Handaya Saputra, Muhammad Shohibi, Masatoshi Kubouchi
Makara Journal of Technology
Fly ash is a silica or alumino silica material that can be used as a constituent of cement in the concrete manufacturing process. Utilization of fly ash aims to improve durability and minimize the reduction of concrete’s compressive strength exposed to an acidic environment, which can be achieved through the pozzolanic reaction of fly ash with Ca(OH)2 within concrete. The reduced content of Ca(OH)2 through pozzolanic reaction will minimize the tendency of ettringite formation (compounds that cause deterioration and decrease the compressive strength of concrete). In order to determine the relation between fly ash replenishment into concrete with concrete’s characteristics …
Improving Renewable Energy Transition Acceptance: A Simulation Gaming Approach On A Multi Actor Setting In The Netherlands, Aziiz Sutrisno, Jac A. M. Vennix, Noor Syaifudin
Improving Renewable Energy Transition Acceptance: A Simulation Gaming Approach On A Multi Actor Setting In The Netherlands, Aziiz Sutrisno, Jac A. M. Vennix, Noor Syaifudin
Makara Journal of Technology
The Netherlands have tried very hard to increase their renewable energy sources (RES) shares to fulfill the European Union target in 2050. However, RES performance did not show the expected result as the performance declined in 2009 producing even wider gap compare to the target. The Dutch government’s tried to incorporate all interested stakeholders by forming the Dutch energy transition task force. Nevertheless, the task force’s result is also not showing a desirable trend. Key reasons behind the Dutch low RES performance are the lack of shared understanding and positive attitude toward RES development among interested actors. This research uses …
Oxidation Process Of H 2 O /Uv For Cod Reduction Of Wastewater From Soybean Tofu Production, Komala Pontas, Abrar Muslim
Oxidation Process Of H 2 O /Uv For Cod Reduction Of Wastewater From Soybean Tofu Production, Komala Pontas, Abrar Muslim
Makara Journal of Technology
Chemical Oxygen Demand (COD) reduction of wastewater from soybean tofu production was studied by conducting advanced oxidation process (AOP) using hydrogen peroxide with UV radiation catalysts in a closed cylindrical glass reactor. The hydroxyl radical (*OH) concentration from H2O2 decomposition was modeled, and exponential trends were found for the *OH concentration over radiation time and operation temperature. As a result, it was found that the maximal *OH concentration was 0.209 mol L-1 at 240 minutes and 50 °C. The *OH concentration exponentially increased following rise in operation temperature. The H2O2/UV AOP application reduced COD concentration to approximately 42.41% from 10,545 …
Uplift Of Shoreline Regions On Pagai Island Due To The September 12, 2007 Mw 8.4 Earthquake Captured By Sar Image, Ashar Muda Lubis
Uplift Of Shoreline Regions On Pagai Island Due To The September 12, 2007 Mw 8.4 Earthquake Captured By Sar Image, Ashar Muda Lubis
Makara Journal of Technology
At least 25 people were killed by the September 12, 2007 Mw 8.4 Bengkulu earthquake, and many buildings were destroyed in Bengkulu and West Sumatra provinces. It is very important to estimate the earth surface deformation due to the earthquake to understand the rupture size and its process. The aim of this research is to estimate the shoreline change and vertical displacement on Pagai Island associated with the September 12, 2007 Mw 8.4 Bengkulu earthquake. The intensity of ALOS-PALSAR satellite images is used to access the pattern of displacement. The result shows that Pagai Island demonstrated huge uplift due to …
Dual-Band Singly-Fed Proximity-Coupled Tip-Truncated Triangular Patch Array For Land Vehicle Mobile System, Basari Basari, Josaphat Tetuko Sri Sumantyo
Dual-Band Singly-Fed Proximity-Coupled Tip-Truncated Triangular Patch Array For Land Vehicle Mobile System, Basari Basari, Josaphat Tetuko Sri Sumantyo
Makara Journal of Technology
This paper proposes a dual-band left-handed circularly polarized triangular-patch array that is developed for land vehicle mobile system aimed at mobile satellite communications. The array consists of six tip-truncated triangular patches, which the first three patches are used for reception and the second three patches are used for transmission purpose. Each of three-patches has a beam pattern that can be switched in three different 120°-coverage beam in azimuth-cut plane at a minimum targeted gain at a desired elevation angle. The targeted minimum gain of the array is 5 dBic, in order for data communications with a large geostationary satellite can …
Improvement Of Quality Of Carica Papaya L. With Clove Oil As Preservative In Edible Coating Technology, Eny Kusrini, Anwar Usman, Chrispine Deksita Wisakanti, Rita Arbianti, Dedy Alharis Nasution
Improvement Of Quality Of Carica Papaya L. With Clove Oil As Preservative In Edible Coating Technology, Eny Kusrini, Anwar Usman, Chrispine Deksita Wisakanti, Rita Arbianti, Dedy Alharis Nasution
Makara Journal of Technology
We have studied utilization of essential clove oil, extracted from clove buds by hydrodistillation, as preservative in edible packaging technology. Preservative of essential clove oil was applied on chopped papaya fruits by using two methods, namely spray and brush. The effects of concentration of clove oil from 0.05 to 0.20% on the preservation of papaya fruits (Carica papaya L.) at room temperature (25 °C) were also evaluated. Physicochemical and in vitro microbiological activities on the papaya fruits that were stored at 25 oC and 85-90% relative humidity were investigated in details. The results indicate that the clove oil at concentration …
Application Of Fiscal Incentives For Development Of East Natuna Gas Field For Long-Term National Natural Gas Demand, Marwan Batubara, Widodo Wahyu Purwanto, Akhmad Fauzi
Application Of Fiscal Incentives For Development Of East Natuna Gas Field For Long-Term National Natural Gas Demand, Marwan Batubara, Widodo Wahyu Purwanto, Akhmad Fauzi
Makara Journal of Technology
East Natuna gas field, which has proven reserves of 46 trillion cubic feet, is projected to meet long-term natural gas needs. However, CO2-content of the gas reserves reaches 71%, leading to expensive development costs. This research investigates the feasibility of the field based on several fiscal incentives. Firstly, gas supply-demand until year 2040 was analyzed. Then, based on the analysis, the field was developed using high CO2 gas separation technology to produce gas of 1300 MMSCFD in 2023, 2600 MMSCFD in 2031, and 3900 MMSCFD in 2039. Finally, the economic feasibility was assessed using cash flow analysis in accordance with …
Transmission Electron Microscopy Characterization Of High-Temperatur Oxidation Of Fe-20cr-5al Alloy Prepared By Focused Ion Beam Technique, Mohammad Dani, Pudji Untoro, Teguh Yulius Surya Panca Putra, Parikin Parikin, Joachim Mayer, Arbi Dimyati
Transmission Electron Microscopy Characterization Of High-Temperatur Oxidation Of Fe-20cr-5al Alloy Prepared By Focused Ion Beam Technique, Mohammad Dani, Pudji Untoro, Teguh Yulius Surya Panca Putra, Parikin Parikin, Joachim Mayer, Arbi Dimyati
Makara Journal of Technology
The Focused Ion Beam (FIB) technique was applied for cross section preparation of the oxidized alloy for Transmission Electron Microscopy (TEM) study. Prior to preparation, the specimens of Fe-20Cr-5Al alloy sheet were oxidized in air at 1200 oC for 2 minutes, 10 minutes, 2 hours, and 100 hours. The microstructure and elemental composition of the samples were characterized using TEM equipped with an Energy Dispersive X-Ray Spectroscopy (EDX). The Electron Energy Loss Spectroscopy (EELS) was used to determine of the light elements. The TEM investigation reveals remarkable microstructure evolution of the specimens during oxidation which generally exhibit a typical multi-layer …