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INDONESIA
Teknologi Indonesia
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 8 Documents
 1 
Search results for , issue " Vol 37, No 3 (2014)" : 8 Documents clear
INVESTIGATION OF Cu, Mn OR Ti ION SUBSTITUTIONS ON THE MICROWAVE ABSORBANCE PROPERTIES OF BARIUM HEXAFERRITE Sebayang, Perdamean; Sari, Ayu Yuswita; Ginting, Masno; Ginting, Riski Titian
Teknologi Indonesia Vol 37, No 3 (2014)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (16.054 KB) | DOI: 10.14203/jti.v37i3.233

Abstract

The influence of Cu, Mn or Ti ion substitution on the microwave absorbance properties of Barium M-Hexaferrite (BaFe12O19) has been investigated. The sample preparation was held by mixing the raw material of Copper oxide (CuO), Manganese oxide (MnO) or Titanium dioxide (TiO2) with a different composition into BaFe12O19 powder through ball milling process, then sintered at 1100oC for 2 h. The substitution composition for each metal ion (Cu, Mn or Ti) into BaFe12O19 powder was 0.1 and 0.5 % mol. The Vector Network Analyzer (VNA) measurement was used to determine the reflection loss and absorption properties of BaFe12O19 samples within frequency ranging from 410 GHz. The minimum reflection loss 20.3 dB at 4 GHz was achieved, which is related to the 0.1% mol of Ti substitution on BaFe12O19 sample. The reflection loss values could be modified by controlling the metal ions composition which consequently improves the microwave absorption properties. The complex permittivity and permeability were calculated using Nicholson-Ross Weir (NRW) method. The peak of real and imaginary parts of permittivity was consistently appeared at 5.05, 5.92, 6.76, and 7.75 GHz for all metal ions (Cu, Mn and Ti). Furthermore, the complex permeability was found to be independent from frequency and the ion substitution did not significantly influence hexagonal structure and particle size distribution of Barium hexaferrite.
UTILIZATION OF BIOPULPING BLACK LIQUOR AS PRESERVATIVE TO FUNGAL ATTACK ON JABON WOOD (Anthocephalus cadamba Miq.) Anita, Sita Heris; Fatriasari, Widya; Zulfiana, Deni
Teknologi Indonesia Vol 37, No 3 (2014)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (16.051 KB) | DOI: 10.14203/jti.v37i3.229

Abstract

Biopulping black liquor, byproduct from biopulping process using white-rot fungi (Phanerochaete chrysosporium) that has been incubated for 30 and 45 days, was used as preservative of Jabon wood (Anthocephalus cadambaMiq.). The main objectives of this study was to investigate the effect of various dipping durations of preservative on absorption process into wood and the weight loss of un-preserved and preserved wood againts fungal attack. Preservation method used in this study was dipping method with various dipping durations (i.e. 10, 30, and 60 minutes) with triplicate. The result showed that dipping process of of Jabon wood into biopulping black liquor for 60 minutes demonstrated the highest retention, i.e.0.21 g/cm3. The weight losses suffered fom by un-preserved and preserved Jabon wood were 55.19% to 55.67% and 6.64% to 12.78%, respectively. Biopulping black liquor had improved the resistance of Jabon wood to both white-rot and brown rot fungi attacks compared to untreated wood sample.
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

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (16.051 KB) | DOI: 10.14203/jti.v37i3.230

Abstract

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.
THE EFFECT OF COAGULANT TYPE ON COLOR REDUCTION VARIATION PATTERN OF PEAT WATER IN COAGULATION-FLOCULATION PROCESS Sutapa, Ignasius D. A.; Toruan, Reliana L.
Teknologi Indonesia Vol 37, No 3 (2014)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v37i3.226

Abstract

Peat water has a wide variety of organic content; one of those is humic acid which looks like a seemingly brownish red color on the water. In a clean water system, the requirements that can be used for consumption islow intensity of color 15 TCU, while the peat water at Sala river was 540 TCU. Coagulation process has been known to affect the color reduction on peat water, but it is not yet known exactly how the optimum concentrationof coagulant. The aims of this study was to determine of PAC and alumunium sulphate effect to variation pattern of color reduction on peat water coagulation process, so that the optimum coagulant dosage, precipitation time and efficiency would be found out. The method used in the coagulation process was jar test. Based on this research, PAC and Aluminum sulphate optimum dosis were 180 ppm and 160 ppm, respectively. By such a dose, the color of the peat water can be reduced which is shown by the intensity of the color variations pattern. The efficiency of PAC within reduced peat water color was 99.63% (540 ppm to 2 ppm) and cost required was Rp 1800/day for 1 m3. Meanwhile, the efficiency of Alum was 95.37% (540 ppm to 22 ppm) and cost required was Rp 640/day for 1 m3. The use of PAC is considered more efficient and profitable than that of Alum, because using Alum needs peat water pH neutralization, and then it hikes the cost of peat water treatment. So, PAC is recommended on the scale of peat water treatment plant.
MECHANICAL AND MAGNETIC PROPERTIES OF BONDED MAGNET Nd2Fe14B PRODUCED USING BINDER BAKELITE Muljadi, -; Sardjono, Priyo; Sebayang, Perdamean
Teknologi Indonesia Vol 37, No 3 (2014)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v37i3.231

Abstract

Bonded magnet Nd2Fe14B was made with mixing Nd2Fe14B powder and polymer bakelite using compressing method. The bakelite concentration was varied of 5 wt%, 10 wt%, 15 wt%, and 20 wt%. Both Nd2Fe14B and bakelite powders were mixed and milled for 24 hours using a ball mill. The powder was formed by dry pressing and subsequently dried in a drying cabinet at a temperature of 180oC for 4 hours. Then, magnetization process was done using impulse magnetizer, and performed measurements of the magnetic properties such as flux density, remanenceBr, coercivity Hic and energy density (BH)max using Gaussmeter and hysteresis permeagraph. Characterization of mechanical properties such as bending strength (BS) and vickers hardness (Hv) was determined before magnetization. Bakelite concentration had a significant influence on both magnetic and mechanical properties. From the characterization results, the optimum concentration of bakelite was 10% and 15% wt. Bonded Nd2Fe14B magnet obtained had the following properties: BS value of 27.7433.42 MPa, Hv value of 292.65314.33 MPa, the value of the magnetic flux density from 1360 to 1400 Gauss, remanence Br = 4.995:02 kG, coercivity Hic = 7.8 kOe, and energy density (BH)max about 5.13 to 5.24 MGOe at the optimum concentration.
Biomethane and Biohydrogen from Biowaste /Wastewater Sriwuryandari, Lies; Sembiring, T.
Teknologi Indonesia Vol 37, No 3 (2014)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v37i3.227

Abstract

The production of renewable energy from biowaste or liquid biowaste in anaerobic condition by the activity of methanogenic archeabacteria in the central role is known as biomethanation. However, at the high concentration of loading rate of the process, related with the sensitivity of methanogens to the environmental shift, such as pH, heavy metals, sulfide, and hydrogen partial pressure, as well as the need of the methanogens to the strict anaerobic conditions, the methane production often was disturbed, even failed. This is one problem in the biowaste and liquid biowaste conversion into methane. Study on the fermentation process of biowaste/liquid biowaste into hydrogen is an attractive solution on the solving of environmental pollution and the need of energy. The complexity of the hydrogen production is seemly less than that of biomethanation due to the needs of the active microorganisms in the processes.
PERFORMANCE OF MICROWAVE PRETREATMENT ON ENZYMATIC AND MICROWAVE HYDROLYSIS OF BETUNG BAMBOO (Dendrocalamus asper) Fatriasari, Widya; Syafii, Wasrin; Wistara, Nyoman; Syamsu, Khaswar; Prasetya, Bambang
Teknologi Indonesia Vol 37, No 3 (2014)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v37i3.232

Abstract

In this present study, we focused on how the changes in the best microwave pretreatment affected the performance of enzymatic and microwave hydrolysis of pretreated bamboo. This solid fraction was subjected to enzymatic hydrolysis following NRE L protocol and microwave acid-hydrolysis with/without presence of activated carbon (0.5 g/g) at 1% and 5% of sulfuric acid concentration for 512.5 m at 330 watt. Short duration microwave-acid hydrolysis of microwave pretreated bamboo showed better reducing sugar yield than that of enzymatic one. Microwave heating for 12.5 inm at 330 W hydrolyzed with 1% acid using microwave irradiation demonstrated a high reducing sugar yield (25.81% of dry biomass or 27.12% of dry substrate). In this treatment, 37.92% of hollocellulose can be converted into reducing sugar or equivalent to 36.12% of maximum potential sugar released. This yield was increased 6.09 times compared to the highest reducing sugar yield coming from enzymatic hydrolysis using 20 FPU/g of cellulase enzymes. Reducing sugar yield obtained with 5% microwave acid hydrolysis of microwave pretreatment for 5 m at 770 W was equal to the result of hydrolysis for 12.5 m at 330 W. Unfortunately, the activated carbon as solid catalyst in microwave hydrolysis could only reduce brown compound without reducing sugar yield improvement.
Assessment of Biomass Feedstock Availability and Bio-Refinery Sites Selection for Cellulosic Ethanol and Bio-Methane Production (Case Study: Palm Oil Processing Waste as Bio-Refinery Feedstock in East Kalimantan , Indonesia) Andriana, Yusuf
Teknologi Indonesia Vol 37, No 3 (2014)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v37i3.228

Abstract

This study discussed about feedstock availability and bio-refinery sites selection for palm-oil-processingwaste- to-bio-energy industry. A case study was based on existing palm oil millings in East Kalimantan province.The objectives of this research were (1) to assess the availability of palm oil processing waste as feedstock of bio-refinery turning into palm-oil-processing-waste-to-bio-energy industry in East Kalimantan and (2) to select bio-refinery sites in East Kalimantan. Time series analysis was used to assess feedstock availability of palm oil processing waste and Analytical Hierarchy Process (AHP) was used to select bio-refinery sites in East Kalimantan. The result of this research showed that the availability volumes of palm oil waste as raw material for bio-refinery at palm oil processing industry were predicted as many as 2,645,736 tons of empty fruit bunches, 1,814,238 tons palm oil fiber, 806,328 tons palm kernel shell, and 7,345,144 tons palm oil milling effluent in 2022. The appropriate bio-refinery sites for palm-oil-processing-waste-to-bio-energy industry in East Kalimantan based on experts judgment using Analytical Hierarchy Process was Kutai Kartanegara Regency.

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