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Teknologi Indonesia

JTI
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Published by Lembaga Ilmu Pengetahuan Indonesia

ISSN : 01261533 EISSN : 23031913 DOI : -

Core Subject : Science,

Computer Science & IT

JTI is a journal in the Departement of Engineering Sciences - Indonesian Institute of Sciences (LIPI). JTI has policy to publish a new and original research paper or a review paper in The scope of Technology. JTI publishes two issues per year. The journal has been registered with printed-ISSN number as 0126-1533 and electronic ISSN number as 2303-1913.

Arjuna Subject : -

Articles 163 Documents

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A ROBUST WATERMARKING SCHEME AGAINTS VARIOUS ATTACKS BASED ON DCT IN FIVE DIFFERENT POSITIONS OF THE HOST IMAGE AREA Rosiyadi, Didi; Muttaqien, Furqon Hensan
Teknologi Indonesia Vol 36, No 3 (2013)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v36i3.206

This paper proposed a robustness watermarking scheme against various attacks based on Discrete Cosine Transform (DCT) in fi ve different positions of the host image area. The scheme comprises the level of watermark resistance and the level of host image perceptibility against various attacks. Here, the level of resistance of a watermark image can be seen from the value of Normalized Correlation Coeffi cient (NC). Meanwhile, the level of perceptibility of an image of host image can be seen from the value of its Peak Signal to Noise Ratio (PSNR). In this proposed research, a method of the Non Blind Discrete in which a host image is required in the process of extraction is used. This watermark, furthermore, is positioned in a visible way in fi ve different positions of the host image; those are on the upper left, lower left, upper right, lower right and on the middle. For the type of attacks, this research uses geometric attacks consisting of Rotation, Scaling and Cropping. The result of this research then shows the level of resistance and the level of perceptibility for all images, and obtains the most robust watermark scheme against various attacks.

CREEP LIFE ASSESSMENT OF HIGH PRESSURE FEED WATER HEATER (HPFWH) SHELL AT COAL FIRED POWER PLANT Alam, Hilman Syaeful; Djunaedi, Imam
Teknologi Indonesia Vol 38, No 2 (2015)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v38i2.125

The creep life of high pressure feed water heater shell of coal-fired power plant has been evaluated using the fitness for service (FFS) assessment based on creep rupture life calculation. The purpose of this study is to determine the remaining life of the component due to prolonged exposure to high operating temperatures and loading conditions. The assessment procedures consist of level 1, 2, and 3, the operating time which is evaluated based on the designed life of the components, i.e. 25 years. Based on the assessment results using level 1, total creep damage does not meet the requirements because the operating life is below the 25-year designed life, equal to 219,000 hours. However, based on the results of level 2 assessment, the component successfully achieves the design life with remaining life of 204,042 hours. These results are consistent with the assessment results obtained by level 3, but the remaining life of the component is only 6,806 hours after operated for 25 years.

RANCANG BANGUN DAN IMPLEMENTASI SISTEM INFORMASI TERINTEGRASI (INTEGRATED INFORMATION SYSTEM) E-GOVERNMENT BERBASIS OPEN SOURCE Perdananugraha, Gonang May
Teknologi Indonesia Vol 33, No 1 (2010)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v33i1.18

Integrated information system of e-government (http://www.bit.lipi.go.id) which designed and built using Joomla 1.5 aims to raise the potential of information possessed by the Technical Implementation UniTechnology Information Division of LIPI, to be known and exploited by the public. This system also as a forum / medium for UPT-BIT civitas in communicating and exchanging information through the internet. Potential information which poured and integrated into such systems are the potential information of multimedia, the potential information for library, and the potential information for dissemination and collaboration. Joomla features that used in buil ding such systems are JoomlaComment!, Media Player, Agora Forum, DOCman, WbGallery, EventList, AllVideos Reloaded, etc.

STRUCTURAL CHARACTERIZATION OF FRACTIONATED GLYCOLIPID BIOSURFACTANTS SYNTHESIZED BY Pseudozyma aphidis YB205 Sari, Martha; Kartika, I Made; Kusharyoto, Wien
Teknologi Indonesia Vol 39, No 3 (2016)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v39i3.278

Fractionation and structural characterization of glycolipid biosurfactant produced by yeast Pseudozyma aphidis strain YB205 was conducted. The yeast strain was grown in a nutrient broth with crude oil as the carbon sources and the glycolipid biosurfactant produced was isolated. The crude glycolipid was fractionated using column chromatography followed by complete separation and purification using extraction technique employing different organic solvents. The fractions were subjected to activity test using oil displacement assay followed by chemical identity test using thin layer chromatography. In order to elucidate its chemical structure, the most active fraction was subjected NMR and FTIR analysis. Results showed that six major fractions were generated all of which showed biosurfactant activity. Four fractions is fractions 2, 4, 5, and 6 showed glycolipid characteristics and fraction 6 showed the highest biosurfactant activity. Combination of NMR and FTIR spectroscopy spectra indicated that chemical structures of fraction 6 belonged to glycolipid species.

THE INFLUENCE OF SOLVENT TYPES ON THE DERIVATIZATION PROCESS USING BIS-TRIMETHYLSILYL TRIFLUOROACETAMIDE (BSTFA) ON COMPOUNDS ANALYSIS OF ACID, BASE, AND ALCOHOL AS A CHEMICAL WEAPONS DERIVATES Pusfitasari, Eka Dian; Andreas, -
Teknologi Indonesia Vol 36, No 1 (2013)
Publisher : LIPI Press

The existence of chemical weapon compounds is forbidden, but its use is still possible by illegal activities such as terrorism. If the compounds were used, they will soon unravel. Therefore, we have to go through to thedegradation product to detect those compounds. Almost all degradation products of chemical weapons are polar and non-volatile because they have some functional group called -OH and -NH2. Consequently, the analysis of these compounds cannot be directly determined by using gas chromatography without derivatization step process. The aim of this study was to determine the effect of the solvent used as the medium during the process of derivatization using BSTFA. The solvent themselves consist of fi ve types, namely acetonitrile, n-hexane, dichloromethane, chloroform, and carbon tetrachloride. The using of acetonitrile and hexane as the derivatization process media did not yield consistent results on the ratio of the area of the chromatograms. Meanwhile, dichloromethane, chloroform,and carbon tetrachloride generated good results; although for very low analyte concentrations, carbon tetrachloride provided more consistent and higher intensity than the chromatograms of DCM and CHCl3 solvent media. The optimum condition we met from the derivatization process was heat up to 70 C for 30 minutes with the addition of 50 ?l BSTFA, and the solvent used as the derivatization process medium was CCl4.

THE EFFECT OF Pt LOADING ON ELECTROCHEMICAL PERFORMANCE OF CNT-BASED ELECTROCATALYST Yudianti, Rike; Onggo, Holia
Teknologi Indonesia Vol 37, No 3 (2014)
Publisher : LIPI Press

Pt loading on CNT surface as electrocatalyst support affects electrochemical performance of electrocatalyst and proton exchange membrane fuel cell stability. In some recent study, Pt-loaded electrocatalyst was a synthesis using poliol method, undergone by controling weight ratio of Pt percursor and CNT in order to find out the importance of appropriate Pt loading and configuration on electrochemical performance. According to the analysis, Pt-loaded electrocatalyst 23.4 and 36.3% show good material properties and electrochemical performance. Electrocatalyst 23.4% Pt loading was selected for preparing low Pt-loaded electrocatalyst layer by screen printing techniques. Nafion ionomer on electrocatalytic film plays an important role to determine the morphological electrocatalyst surface and performance in changing hydrophobicity and electrochemical properties. Nafion ionomer consequently causes reduction on electrochemical properties from 338.6 to 31.6 m2/g whereas the highest electrochemical surface area (ECSA) is achieved by Pt loading 23.4% in average particle size 3.7 nm, corresponding to Pt activity on hydrogen desorption.

99 PEMBUATAN BAHAN FILTER KERAMIK BERPORI BERBASIS ZEOLIT ALAM DAN ARANG SEKAM PADI Sebayang, P.; Muljadi, -; Tetuko, Anggito P.
Teknologi Indonesia Vol 32, No 2 (2009)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v32i2.9

The porous ceramics filter material have been made from natural zeolit and rice husk charcoal with composition variation (in % of mass). The preparation of zeolit was done using ball mill for 24 hours and rice husk charcoal was prepared using vibrating mill for 1 hour until it can be through out in 100 mesh shieve. The two raw materials about 2 grams were mixed with addition 50 ml of Polivinylalcohol (PVA), then it was mixed again until homogeny. The sample was dried pressed with pressure of 25 kgf/cm and dried in a drying oven at 60 C for 24 hours. The sintering process was done using electrical furnace with heating rate of 10C/minute until it reached temperature of 900 and 1000 C, and holded for 2 hours. From the result of porouc ceramics filter material, the optimum composition is 40% rice husk coke + 60% Zeolit with sintering temperature = 1000 C. At this condition, the properties are density = 2,16 g/cm, shrinkage = 35,94%, porosity = 66,05%, water absorption = 31,10%, modulus of rupture = 7,47 MPa, compressive strength = 4,38 MPa, and coefficient of thermal expansion = 5 x 10 -6 C-1. The result of XRD shows that zeolit has major phase of mordenite (Na8[Al8Si40O96].24H2O) and minor phase of clinoptilolite (Na6[Al6Si36O72].24H2O). The result of XRD on 40% rice husk coke + 60% Zeolit and sintering temperature = 1000 C shows that the major phase is mullite (3Al2O3SiO2) and the minor phase is tridimite (SiO2). Meanwhile, the picture of SEM shows that porous ceramics have irregular particle with size between 110 ?m and its pore size can reaches 20 ?m.

FLOW RATE OF CARRIER GAS AFFECTING THE KEY PARAMETERS OF GC-TCD FOR CO2, C3H8, AND CO ANALYSIS: AN EXPERIMENTAL INVESTIGATION Zuas, Oman; Budiman, Harry
Teknologi Indonesia Vol 39, No 2 (2016)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v39i2.240

This paper reports on the effect of flow rate of helium (He) carrier gas on the key parameters of gas chromatography equipped with thermal conductivity detector (GC-TCD) for the measurement of carbon dioxide (CO2 ), propane (C3H8) and carbon monoxide (CO) in gravimetric standard gas mixture (Grav-SGM). The carrier gas has a function to transport vaporized molecules through the column during the GC separation process. The study provides opportunity to experimentally investigate the effect of gas flow rate on the several key parameters of the GC-TCD including retention time, peak area, peak height, response factor, resolution and selectivity. The results show that all key parameters were found to be carrier gas flow rate dependent. The increase of the gas flow rate could significantly decrease the retention time, peak area and response factor of the gas components. While both resolution and selectivity factor were observed to have a substantial decrease with increasing the flow rate of carrier gas. Therefore, proper selection of flow rate level of carrier gas is suggested before a GC measurement is carried out for obtaining an optimum condition.

BIOTRANSFORMASI 3-SIANOPIRIDIN MENJADI NIKOTINAMIDA DENGAN SEL CORYNEBACTERIUM D5 SEBAGAI BIOKATALIS Sunarko, Bambang; Sulistinah, Nunik
Teknologi Indonesia Vol 34 (2011)
Publisher : LIPI Press

A number of microbes isolated from industrial effl uents were studied to characterise their capability to convert 3-cyanopiridine. Isolate D5, identifi ed as Corynebacterium D5, was able to hydrolise 3-cyanopridin to nicotinamide, nicotinic acid, and ammonia catalyzed by nitrile-hydratase and amidase. The activity of nitrile-hydratase and amidase of Corynebacterium D5 were 0.364 U nad 0.200 U, respectively. The optimum hydrolisis of 3-cyanopiridine were occurred at 25oC and pH 7.0. Corynebacterium D5 exhibited the best growth (0.43 g cells dry weight/liter), when 0.5% (v/v) acetonitrile and 20 mM 3-cyanopiridine were used as sources of carbon, energy, and nitrogen.

Optimization of Radioisotope Production at Rsg-Gas Reactor Using Deterministic Method Pinem, S; Susilo, J; Tukiran, -; Sembiring, T.M.
Teknologi Indonesia Vol 35, No 2 (2012)
Publisher : LIPI Press

RSG-GAS is a research reactor operated for radioisotope production, material testing, research and development and also industry and university needs. The radioisotope productions are Mo-99/Tc-99m, TeO2, Iridium, Sm2O3, Gd2O3, MoO3 and others which are needed for hospital and industry. To meet all demand, optimization of irradiation has been done for increasing the target irradiation in the core so that the utilization of RSG-GAS core is also increasing. This is important to be done because the target insertion to the core will change the core characteristic and can disturb the reactor operation safety. This paper will analyz the infl uence of each target insertion and also combination of the targets insertion to the core while considering the reactor operation safety factor. The calculation of the optimization was done by a deterministic method using Standard Reactor Analysis Code (SRAC) computer code. Meanwhile the determination of optimum target was done by analyzing the infl uence ofchanges in the reactivity and radial power peak factor due to the insertion of the target in the core. Based on the calculation the number of maximum target insertion for fi ssion product molybdenum-low enrichment uranium (FPM-LEU) to get Mo-99/Tc-99m in all irradiation positions has been achieved. The E-4 and G-7 are the best core grid positions for the FPM-LEU target with the maximum mass of 21 g. Beside that, several data for calculation of TeO2, Iridium, Sm2O3, Gd2O3, MoO3, targets with different numbers and also combination of all targets have been achieved as well. Research works is ready to be applied in the management of irradiation target for optimum radioisotope production in the RSG-GAS reactor.

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