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INDONESIA
Teknologi Indonesia
ISSN : 01261533     EISSN : 23031913     DOI : -
Core Subject : Science,
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
PECTINASE PRODUCTION BY ASPERGILLUS USTUS BL5 AT SOLID STATE FERMENTATION MEDIUM USING AGRICULTURAL BIOMASS Rahmani, Nanik; Andriani, Ade; Anggraini, Yufi Sara; Yopi, -
Teknologi Indonesia Vol 36, No 3 (2013)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (16.051 KB) | DOI: 10.14203/jti.v36i3.210

Abstract

This research showed that Indonesian agricultural biomasses, such as Siam orange peel, Medan orange peel, Durian peel and old tea leaves contain a pectin that are a potential material for use as a substrate for pectinase production. From the four types of biomasses used, Medan orange peel produced pectinase activity with the highest value equal to 1.28 U/mL. Optimization of fermentation conditions showed that Aspergillus ustus BL5 pectinase production were affected by the concentration of substrate, media pH, and temperature of the fermentation. Optimization of process showed that the optimum substrate concentration, pH and temperatuter were 10%, 4 and 40C with pectinase activity of 1.37 U/mL, 2.85 U/mL, and 1.92 U/mL respectively. Pectin content in the medium has a proportional relationship with the activity of the enzyme pectinase produced. The high content of pectin in Medanorange peel making pectinase enzyme activity produced on the substrate is also high.
HYDROGEOLOGICAL STUDY TO SUPPORT SIGANDUL BRIDGE CONSTRUCTION AT PARAKAN, TEMANGGUNG, CENTRAL JAVA Utomo, Edi prasetyo; Purwoarminta, Ananta
Teknologi Indonesia Vol 38, No 2 (2015)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (16.054 KB) | DOI: 10.14203/jti.v38i2.167

Abstract

The plan of making bridge on the Sigandul river in Parakan, Temanggung regency is to improve the quality access roads in the Province of Central Java. The first step was to make the construction of the bridge pillars as the foundation of the bridge. For that purpose it was done drilling with planning a depth of 18 m, but at a depth of 12 m there was out of groundwater in a large discharge. This large groundwater discharge has disturbed the bridge construction process. The aim of this research is to analyze the causes of groundwater discharge and to provide a recommendation on counter measure of disturbance in the process of bridges construction based upon the hydrogeological condition. The methods used in this research were conducting a geological observation on ground surface and geoelectrical measurement with a dipole-dipole electrode arrangement. The results showed that the subsurface of research area is the site of groundwater accumulation and steep slope of its surrounding makes the groundwater came out with high pressure. Discharge rate of groundwater outflow in the area was 91.42 liters per second. Based on these conditions, it is recommended that the process of making a bridge construction should be done by first reducing the groundwater pressure or otherwise moving the foot of bridge the east side.
LIQUID BIOFERTILIZER AND COMPOST FROM ORGANIC MARKET WASTE Sriwuryandari, Lies; Sembiring, Tarzan
Teknologi Indonesia Vol 33, No 2 (2010)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v33i2.22

Abstract

Liquid biofertilizer and compost from organic market waste were produce by the addition of some functional microorganisms. Azospirrillium sp., Azotobacter sp., Lactobacillus sp., Pseudomonas sp. and Actinomycetes were inoculated into liquid or solid raw materials. The ripe biofertilizer were characterized and meets the Indonesian National standards for biofertilizer. Actinomycetes contained in the liquid fertilizer about 2.95 x 108 cfu/ml, which is meet the standard (? 104 cfu/ml) and other functional microorganisms namely Lactobacillus sp., Azospirillium sp., Azotobacter sp., Pseudomonas sp. and phosphate diluters were grown enormously with the population of more than 105 cfu/ml respectively. Qualitative test of the fertilizer shown that the fertilizer are effective for the crops such as Long bean (Vigna unguiculata), Cucumber (Cucumis sativus), Leek (Allium ampeloprassum) and others. Production of biofertilizer using organic market waste support the organic farming and the national policy on the fertilizer.
GC/MS PROFILING AND EVALUATION OF ANTIBACTERIAL AND ANTIOXIDANT ACTIVITIES OF BAYUR (Pterospermum javanicum) BARK EXTRACT Praptiwi, Praptiwi; Fathoni, Ahmad
Teknologi Indonesia Vol 40, No 1 (2017)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (16.054 KB)

Abstract

This study aims to identify the chemical compounds of ethyl acetate extract of the bark of bayur (Pterospermum javanicum) and to evaluate its antibacterial activity and potential antioxidant. The estimation of total flavonoid was done by spectrophotometry method. The chemical compounds were analyzed by gas chromatography-mass spectrometry (GC-MS). The antibacterial assay against Staphylococcus aureus Ina-CC B5 and Escherichia coli Ina-CC B4 was done by TLC-bioautographic method, whereas the potential antioxidant was determined by DPPH radical scavenging assay. Meanwhile, its minimum inhibitory concentration (MIC) value and IC50 of the extract were done on microplate 96 well by serial microdilution method. GC/MS analysis revealed the presence of 31 identified chemical compounds in the extract with total flavonoid was 625 mg CE/gram extract. The MIC values against E.coli Ina-CC B5 and S. aureus Ina-CC B4 were >256 ug/ml. The IC50 from DPPH radical scavenging assay was 48.92 ppm indicating that ethyl acetate extract of the bark of bayur is potent antioxidant.
FPGA-BASED DUAL SIMULTANEOUS SIGNAL GENERATOR USING REDUCED MEMORY DIRECT DIGITAL SYNTHESIS Firmansyah, Iman
Teknologi Indonesia Vol 36, No 2 (2013)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v36i2.201

Abstract

This paper describes the implementation of an FPGA (Field Programmable Gate Array)-based signal generator that simultaneously generates dual frequencies. The example demonstrates the capability of generating twodifferent frequencies at the same time. Direct Digital Synthesis or DDS is implemented as the core in generating the signal. To reduce the memory size, the quadrature symmetry of sine wave is created in order to achieve an effi cient look-up table for DDS core. As a result, only one fourth of total look-up table is allocated for storing the data. The system has been developed for Xilinx Spartan-6 XC6SLX9 FPGA integrated with 12-bit Pmod-AD1 analog to digital converter module consisting of AD7476A. The user sets the voltage input connected to Pmod-AD1 module as input control for changing the frequency; each input is dedicated to one channel of frequency. The system is also integrated with 8-bit Pmod-DA1 digital to analog converter module (AD7303) for generating the output signal. The advantage of parallelism capability in FPGA makes it possible to generate two different frequencies (2.18 KHz and 4.35 KHz) simultaneously.
HYDROGEN PRODUCTION USING Rhodobium Marinum IN MILK LIQUID WASTE Anam, Khairul; Susilaningsih, Dwi
Teknologi Indonesia Vol 38, No 1 (2015)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v38i1.118

Abstract

This study was conducted to investigate the effect of dilution towards milk liquid waste in biologically producing hydrogen gas by photosynthetic bacteria, Rhodobium marinum. The methods included pretreatments of the milk liquid waste by sterilization, filtration, neutralization, and centrifugation, before and after dilution. From several experiments, 100% of milk liquid waste substrate generated the highest hydrogen gas production up to 93.45 16.15 ml, but the highest efficiency was obtained at level 12.5% of milk liquid waste substrate which valued 0.33 mol hydrogen/ mol glucose consumed. Kinetics measurements for hydrogen production process in milk liquid waste which was added with nutrients obtained yield of biomass formed per substrate consumed (Yx/s) i.e. 0.192 g/g, yield of product per substrate (Yp/s) i.e. 0.009 g/g, and yield of product produced per biomass (Yp/x) i.e. 0.043 g/g. For kinetics measurements on the milk liquid waste medium without nutrients addition, obtained Yx/s was 0.261 g / g, Yp/s was 0.019 g/g and Yp/x was 0.070 g/g
OPTIMASI KEMIRINGAN MAGNET PADA GENERATOR MAGNET PERMANEN KECEPATAN RENDAH FLUKS RADIAL Irasari, Pudji; Kasim, Muhammad; Fitriana, -
Teknologi Indonesia Vol 33, No 1 (2010)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v33i1.13

Abstract

Optimization of magnet skewing of 1 kW, 3 phase, 300 rpm permanent magnet generator has been conducted in this research. The optimization is carried out by simulating some position of the rotor magnet skewing (x). The defi nition of skewing in this experiment is the outer line of one pole that is appear due to the shifting of two magnet segments that forming the pole. The three skewing position that is analyzed are x1 = 16 mm, x2 = 21 mm, x3 = 25,6 mm. Those skewing positions result in different harmonic distortion (HD) and EMF voltage waveform. The experimental validation shows that the best characteristic is obtained at skewing of x = 21 mm with HD = 11.9% and has the most sinusoidal EMF voltage waveform.
IRRIGATION PLANNING FOR ORGANIC VEGETABLE DEVELOPMENT FAMILIA SOLANACEAE BANYUMULEK WNT TECHNO PARK widiyono, wahyu
Teknologi Indonesia Vol 39, No 2 (2016)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (16.054 KB) | DOI: 10.14203/jti.v39i2.264

Abstract

Organic vegetable development on chili, eggplant and tomato, Familia Solanaceae is one programme of Banyumulek Techno Park-LIPI, in the West Nusa Tenggara (WNT). The location is in the lowland area with an altitute aroud less than 100 m above sea level, soil texture is sandy loam with rather fast permeability (2.64 cm hour-1 , D3 climate type according to Oldeman Classification with 4-6 wet months and 3-4 dry months. Annual rainfall are varies from 1.553 mm year-1 and 2.779 mm year-1, with average 1.845 mm year-1. Aim of research are (1) to understand surplus and deficit water condition during a year to cultivate chili, eggplant and tomato; and (2) to understand water volume and irrigation time to irrigate crops in order they do not face water deficit. Research methods were conducted through analysis rate of rainfall and evaporation-evapotranspiration during a year, simulation of water deficit, crops water need and irrigation time. The irrigation planning was used as application guide to cultivate above crops in the Banyumulek, demplot.
BALLISTIC IMPACT BEHAVIOR OF WOVEN FABRICS POLYMER COMPOSITES WITH DIFFERENT STRUCTURES AND CONFIGURATIONS Satoto, Rahmat; Nugroho, Pramono; Santosa, Tata
Teknologi Indonesia Vol 32, No 1 (2009)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v32i1.50

Abstract

This study reports the ballistic penetration performance of a composite materials composed of woven Kevlar fabric, woven nylon fabric, woven ramie fabrics impregnated with compatible resins and hybrid composite construction of these three structures. The composite panels were tested by low velocity bullet (around 322 m/s) in incident angle of 0o according to level I NIJ 0101.04. The effects of fabric configuration, composite structure, and the resin compatibility on ballistic performance were investigated. Composites with Kevlar-A363F fabric performed the best among these composites. Composite of 4 layers kevlar-A363F shows the better performance than 32 layer composites of nylon- oxford X7 and 48 layers ramie fabrics. Ballistic penetration mechanism of the fabric-reinforced composites demonstrated that breakage, matrix cracking, and delamination are three typical mechanisms of failure and energy absorption. In the kevlar-A363F composites, ballistic impact causes the blunting of a projectile. This projectile deformation is seen as an effective mechanism of energy absorption. Kinetic energy of a blunt projectile will be absorbed by wider cross section of the next fabric layer, so the projectile velocity slows down until it stops. The enhancement of ballistic performance is shown to be associated with the fiber strength, construction, fabric configuration, and matrix compatibility. It is likely that the best design of bullet proof composite can be identified.
Annual Migration of Monsoon Over Indonesia Maritime Continent Based on OLR Data Yulihastin, Erma; Hermawan, Eddy
Teknologi Indonesia Vol 35, No 3 (2012)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v35i3.191

Abstract

Annual migration of monsoon over Indonesia Maritime Continent (IMC) were analysed by Outgoing Longwave Radiation (OLR) data. Global climatology of NCEP/NCAR Reanalysis II (National Center for EnvironmentalPrediction/National Center for Atmospheric Research) namely OLR, wind, and precipitable water were derived from 1975 to 2010 which have 2,5o spatial degree resolution. The results showed those the annual migration were described by annual cycle of OLR<220 W/m2 occurred almost over IMC related to the wet periods (DJF). Whereas, OLR>240 W/m2 occurred only over south of IMC (3-9o S) related to the dry periods (JJA). Zonal variation of OLR showed annual cycle occured in areas of 2-10oS and 5-10oN, respectively. On the other hand, meridional variation described annual cycle in areas 90-120o E and 90-150, which respectively mentioned as area I and area II. Annual cycle of OLR in area I was symmetry with area II. Also, in areas I and II, parameters of OLR and precipitable waterwere symmetry each other. Signifi cants anticorrelation between OLR and precipitable water were -0.89 and -0.95 in area I and II, respectively.

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