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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 163 Documents
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INVESTIGATION OF THE PERFORMANCE OF SINGLE AND MULTI-CELL STACKS OF PEMFC -, Indriyati; Irmawati, Yuyun; Subhan, Achmad
Teknologi Indonesia Vol 38, No 3 (2015)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (16.054 KB) | DOI: 10.14203/jti.v38i3.132

Abstract

The performance of single, 3-cell, and 5-cell stacks of PEMFC have been experimentally investigated. Emphasiswas placed on the effect of different operating condition including hydrogen/oxygen flow rate and pressure on thePEMFC performance through analysis of polarization curves. The results showed that flow rate slightly affected theperformance of single-cell PEMFC at higher current densities whereas no significant differences were observed atlower current densities. Similar curve patterns were obtained when testing the single and 3-cell PEMFC stacks withvariation of backpressure. Increasing backpressure gives positive effect on the stack performance due to improvingthe reaction at the electrodes. However, this behavior did not occur on 5-cell PEMFC stack the performance of which decreased as the backpressure increased from 5 to 10 psi due to increasing water production in the cathode. In this study, the highest operational (at voltage of 0.6 V) current density of 85.6 mA/cm2 was obtained from 3-cell stack with flow rate of H2/O2 and backpressure 800/1,000 ml/min and 10 psi, respectively. This good performanceis more evident when the 3-cell stack was evaluated over a quite long operation time. After decreasing gradually at the first 50 min operation, the performance of 3-cell stack of PEMFC remained stable up to 200 min, while it fluctuated in 5-cell stack due to poor water management. This study confirms that the performance of PEMFC stack is highly influenced by the number of cell and operating condition, and the performance of PEMFC stack is not linear as function of number of cell.
PERTUMBUHAN IN VIVO BULUH SERBUK SARI DALAM STIGMA GINSENG JAWA (TALINUM TRIANGULARE) PASCA PENYERBUKAN BUATAN: EFEK DONOR SERBUK SARI Rachman, Erlin; Tihurua, Eka Fatmawati
Teknologi Indonesia Vol 34 (2011)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v34iKhusus.35

Abstract

Talinum triangulare Wild. pollen were germinated in vivo in the stigma with three hand pollination treatments based on pollen donor in order to know its germination rate and if the pollen tube growth rate affected by pollen origin. Flower buds were picked at prior to anthesis time and let them to anthesize in laboratory condition. The three pollination treatments were directly excecuted at full anthesis stage and four different incubation times: 5, 10, 15 and 20 minutes. The experiment was conducted twice with about one month interval between November and December 2008. Signifi cantly different pollen tube growth rate was only showed between stigma pollinated by pollen from neighbor fl owers of same individual and stigma pollinated by pollen from next indidual plant. Highest final pollen germination level and tube growth rate was resulted by hand pollination with pollen from neighbour flowers of the same individual called geitonogamy (54.84% and 9.081 ?m per minute). Second highest was pollination with pollen from the flower itself called autogamy (45.92% and 6.806 ?m per minute). The lowest was hand pollination with pollen from flowers of outside individual called exogamy (39.61% and 3.525 ?m per minute). Stagnated growth of pollen tubes after pollination with outside pollen in exogamy at fi rst minutes of incubation may be related to individual adaptation.
STUDY OF IPAG60 PLANT PERFORMANCE RELIABILITY IN TREATING DIFFERENT PEAT WATER TO SUPPORT CLEAN WATER SERVICES IN PEATLAND AREAS Sutapa, Ignasius Dwi Atmana
Teknologi Indonesia Vol 40, No 2 (2017)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v40i2.471

Abstract

Surface water, including rivers, lakes or ponds, in peatland areas has specific characteristics. Generally, this type of water has high level of acidity, organic matter, and high concentration in several metalic ions, like manganese and iron. The content of organic matter is usually indicated by dark brown color of water. In term of quality, this water is not suitable to be used directly for covering daily needs, such as drinking, cooking, and bathing by the local people. IPAG60 was proven as a small scale plant which has a good ability for treating different types of peat water to produce clean water as per the standards. This plant gives alternative technology to support clean water services in peatland areas.
PENGARUH PENAMBAHAN POLY(TETRAFLUOROETHYLENE) PADA KARAKTERISTIK KOMPOSIT BACTERIAL CELLULOSE/ MULTI-WALLED CARBON NANOTUBES Onggo, Holia; Yudianti, Rike
Teknologi Indonesia Vol 35, No 1 (2012)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (16.051 KB) | DOI: 10.14203/jti.v35i1.173

Abstract

In order to obtain new materials as alternative carbon paper, the bacterial cellulose/multi-walled carbon nanotube (BC/MWCNT) composites were made with and without PTFE by helping agarose, via heating process. The effect of PTFE addition on characteristic BC/MWCNT composite have been studied using thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and impedance bridge. The electrically conductivity of BC / MWCNT/ AG composite (without PTFE addition) is 15.1 x 10-2 S/cm (in-plane) and 0.3 x 10-2 S/cm (through plane). Above 150oC, the composite tends to be destroyed leading to electrical conductivity measurements cannot be performed. In the BC/MWCNT/AG/PTFE composite, heating from 150 to 330oC increased electrically conductivityfrom 4.5 to 24.5 x 10-2 S/cm (in-plane) while through-plane electrically conductivity tend to be stable (0.020.03x10-2 S/cm). After heating at 400oC, the composite was seen better thermal stability but the electrically conductivity was decrease because of carbon particles from AG and BC were decomposed and coating of MWCNT. The PTFE addition was not only for increasing the thermal stability but also as coating material of BC/MWCNT composites.
ANALYSIS OF DEFIBRILLATION ENERGY EFFECT ON ELECTROCARDIOGRAPH (ECG) Ardiatna, Wuwus; Hidayat, Siddiq Wahyu; Sadrach, Junaid; Hidayat, Asep Rahmat
Teknologi Indonesia Vol 36, No 3 (2013)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v36i3.209

Abstract

The analysis of determination of defi brillation energy effect on Electrocardiograph (ECG) according to IEC 60601-2-27: 2005 has been conducted in order to measure the energy reduction during defi brillation process on EKG. The result showed the energy differences before and after being connected to ECG was 4,408%.
RHODOCOCCUS PYRIDINIVORANS STRAIN TPIK, A NITRILE-DEGRADING BACTERIUM ISOLATED FROM TAILING POND OF ANTAM GOLD MINING INDUSTRY , PONGKOR Sulistinah, Nunik; Riffiani, Rini; Sunarko, Bambang
Teknologi Indonesia Vol 38, No 2 (2015)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v38i2.158

Abstract

Nitriles are widely manufactured and extensively used by chemical industries as synthesis intermediates. Although these compounds are generally highly toxic, due to their cyano functional group, they can be used by some microorganisms as carbon and/or nitrogen sources. Nitrilase catalyzes the direct cleavage of nitriles to the corresponding acids and ammonia, where as nitrile-hydratase catalyzes the hydratation of nitriles to amides. Applications of these nitrile-converting enzymes are now increasingly recognized for the production of several pharmaceutically important compounds and fine chemicals. By virtue of their capability to eliminate highly toxic nitriles, the enzymes also play a significant role in protecting the environment. Accordingly, it is very important to find microorganisms that have a great capacity to utilize or degrade nitriles. Recently, a bacterial isolate TPIK which shows high nitrile degrading activity has been isolated. The strain was isolated from tailing pond of gold mine activity by selective enrichment methods. TPIK was shown to be capable of degrading high concentrations of nitrile (up to approx. 1 M acetonitrile). Colonies of TPIK are light orange in colour and have irregularly round wrinkles. The cells of TPIK are non-spore-forming, non motile and Gram-positive, but are Gram-variable in old cultures. The cells are rods and brached fillaments during the early growth phase and then fragmented into short rods and cocci. The taxonomic position of TPIK was clarified using molecular genetic methods. The phylogenetic tree showed that bacterial isolate TPIK falls within an evolutionary radiation comprising Rhodococcus species and is most closely related to the type strain of Rhodococcus pyridinivorans, sharing 99% 16S rDNA similarity. To the best of our knowledge, this was the first time that Rhodococcus pyridinivorans has been described as containing nitrile-degrading enzymes. Usually, this bacterial strain has been studied for its ability to degrade carcinogenic compounds, like pyridine.
PEMBUATAN KERAMIK GERABAH BERBASIS LIMBAH PADAT DARI INDUSTRI PULP DAN TANAH LIAT Sebayang, p.; Ginting, Masno; Henry, -
Teknologi Indonesia Vol 33, No 2 (2010)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v33i2.21

Abstract

The earthenware ceramics have been made based on solid waste from pulp industry (sludge) and clay with various composition (in persentage mass). The preparation of raw materials was done using ball mill for 24 hours until it can pass through 100 mesh shieve. Then those raw materials mixed with 50 ml Polivinylalcohol (PVA), and stirred until homogeneous. The sample was formed using dry pressing with pressure of 25 kgf/cm and dried in a drying oven at 60C for 24 hours. The sintering process using electrical furnace with heating rate of 10C/minute, when, the temperature reaching 900C, it is hold for 2 hours. The optimum composition of earthenware cera mics is 50% solid waste from pulp industry (sludge) and 50% clay with sintering temperature of 900C for 2 hours holding time. At this condition, the properties are: bulk density = 1.37 g/cm, crystal density = 2.71 g/cm, porosity = 39.26 %, and compressive strength = 62.90 kgf/cm2. From the XRD analysis it is shown that there are 5 phases such as: silicon oxide (SiO2), calcite (CaCO3), calsium oxide (CaO), magnesium silicate (MgSiO3) and sillimanete (Al2SiO5). The dominant phase is Calcite (CaCO3) while others are minor phases. From SEM measurement it is shown that the particles of the earthenware ceramic has irregular shape, with particle size less than 5 ?m and pore size less than 1 ?m.
THE CHARACTERISTICS OF VETIVER GRASS AS A PHYTOREMEDIATOR PLANT IN DOMESTIC GREYWATER TREATMENT Astuti, Jovita Tri; Sriwuryandari, Lies
Teknologi Indonesia Vol 39, No 3 (2016)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v39i3.313

Abstract

Source separation of domestic wastewater into greywater (GW) and blackwater (BW) streams is important in decentralizing treatment due to its different characteristics. GW is generated from bathroom, washing machine,kitchen sink, and vehicle washing. Meanwhile, BW is produced from toilet, urinal or bidet. In developing countries, untreated wastewater is widely used in agricultural and risk to human health and living organisms. The appropriate treatment is required to prevent water degradation. Phytoremediation is a sustainable way to mitigate pollution with using plant. This study was conducted to observe the characteristics of vetiver grass as phytoremediator for GW. There are two factors of treatment. First is growth media (M), i.e. tap water (TW) as control (M0) and GW (M1). The second is vetiver (V), i.e. without (V0) as control and with planting (V1). Three glass aquariums are used for each treatment as replicates. Eight individual stem bases of vetiver were placed at aquarium and allowed hydroponically growing. At harvesting (49th day), vegetative organs were collected and observed separately, i.e. root, stem and leaf. Pollutant removal was calculated by comparing the content before and after treatment of media with vetiver. Cultivation of vetiver in GW (M1V1) could increase the root number, total root length, and total root diameter as much as 54%, 92.2%, and 51%, respectively. Individual root length was in the range of 2.3-78.5cm and root diameter was 0.35-2.10mm. Compared to the initial, stem number increased 99%, while leaf number increased 4 times. Root/Shoot (R/S) ratio was 0.80±0.14. Polutant removal of GW by vetiver achieved 72.86% BOD5; 65.51% COD; 66.55% TN; 67.67% TP; 80.77% Fe; 71.43% Zn; 60% Pb; 65.81% detergent, and 100% phenol. Vetiver could reduced TPC 29.13%, MPN coliform 78.18%, and MPN fecal coli 91.54%. After treated with vetiver, GW complied to criteria of water Class IV that can used for irrigation in agricultural.
METHOD DEVELOPMENT OF SONICATION TECHNIQUE EXTRACTION FOR DETERMINATION OF CARBOFURAN PESTICIDE IN SPIKE SOIL SAMPLE BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY Yusiasih, Retno; Pitoi, Mariska M; Ariyani, Miranti
Teknologi Indonesia Vol 41, No 1 (2018)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (16.054 KB) | DOI: 10.14203/jti.v41i1.527

Abstract

A method for determination of carbofuran pesticides residue utilizing extraction by sonication has been developed for spike soil sample collected from horticulture farms in Lembang, North Bandung Regency, Indonesia. The simple, reliable, and cost-effective method was performed without any clean up prior injection to HPLC-UV. The method was validated by evaluating its detection limit, linearity, repeatability, recovery, and matrix effect. The detection limit of the method is 0.50 mg/kg. The linearity of the method is very good (r=0.99677) for concentration range of 1.0 to 5.0 mg/kg. The repeatability of the method is acceptable (CV value of 2.56 %). The fortified recoveries are acceptable, ranging from 93.44 to 101.03%. Statistical analysis shows that the matrix effect is insignificant to the method. The application of the method is able to offer a minimization of waste, miniaturization of method, and increased the safety for the operator as required for Green Analytical Chemistry.
THE PRODUCTION OF FREEZE-DRIED PROBIOTIC FROM NAPPA CABBAGE JUICE BY LACTIC ACID BACTERIA Ningrum, Dyah Ratna; Budiwati, Thelma Agustina; Nissa, Rossy Choerun; Mawarda, Panji Cahya
Teknologi Indonesia Vol 41, No 1 (2018)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v41i1.461

Abstract

The suitability of nappa cabbage juice as raw material to produce freeze-dried probiotics by selected lactic acid bacteria, (Lactobacillus bulgaricus and Streptococcus thermophillus) has been investigated. The addition of filler in a form of rice and soybean flour mixture as protective material for viable cells was also assessed. The liquid mixture was fermented at 30oC for 24 h and sampled at 0 h, 14 h, 24 h and after it was freeze dried at -20oC. Soybean and rice flour mixture of 10% was added after 14 h of incubation. Titrable acidity, pH, and the number of viable cells were measured during fermentation and after the probiotics had been freeze dried. The carbohydrate, sucrose, lactose, and protein content of each freeze-dried probiotic was also determined. The freeze-dried probiotics analysis showed lactic acid bacteria reduced the pH to as low as 3.69 from 4.50 and increased the acidity from 2% to as high as 6.85%. The filler added to the mixture was found capable of partially protecting the viable cells to as high as 2.45 x 105 CFU/mL during freeze drying process. Lactobacillus bulgaricus exhibited slightly higher production of lactic acid than Streptococcus thermophilus even though Streptococcus thermophilus had higher viable cells. The nutrient composition of each freeze-dried probiotic showed closely similar content of carbohydrate and lactose whereas Streptococcus thermophilus had higher concentration of protein and sucrose. This study concludes that nappa cabbage juice could be utilized to produce freeze-dried probiotics.

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