|Ambar Susilorukmi, L. Sriwuryandari and T. Sembiring||Oil Derivatives in Water Bodies and Sediments of East Kalimantan||To study oil spill distribution on public services location surrounded to oil exploration or oil tanker transportation area, some samples originated from Mahakam Delta and beach of East Kalimantan were analyzed. Geographical position of each sampling point was determined by using GPS (Global Position System). Water and sediment samples were both collected from each of sampling point and than analyzed on physic, chemistry, and microbiology. The average temperature was around 28.5–32°C and acidity was around neutral (pH = ±7). Meanwhile, dissolved oxygen was lower than normal level for living organisms. Each of water and sediment sample contained total oil extracted of 50-2650 and 280–4806.07 mg/l, respectively. That level was much more higher than National Regulation (PP No. 20, 5 Juni 1990) for drinking water and fishery. Oil derivatives of aromatic compounds were detected from all of samples. In addition, microorganism population inhibiting in all of sample was very scarce.|
|M. R. Djuwansah dan Ida Narulita||Neraca Air Spasial di Bagian Hulu DAS Citarum Sebagai Basis Data Anggaran Air||Spatial Water balance of the Upper Citarum Watershed have beed developed in order to asses the carrying capacity of the area for the purposes of water resources management. This area is considered as the most degraded area in point of view of water resources in Indonesia due to the high population density and their intensive activity. For this kind of area, more precise and measurable land and water resources allocation is indispensable and water budget approach looks suitable for both water resources and land use management. Monthly water balance calculation was carried out using Thornwaite method. Input data used were climatic data recorded at 11 stations within the sub-watershed, Landsat image derived existing land-use map and soil map. Spatial distribution for every water balance thematics was plotted on 1:50 000 scaled topographic map as a base map using GIS software. Spatial monthly water balance can be used as distributed monthly water budget data base for the studied area, and further can be used for the purpose of water resources management evaluation and planning.|
|Lies Sriwuryandari dan Ambar Susilorukmi||Penggunaan Kultur Mikroorganisme Campuran untuk Bioeliminasi Cemaran Minyak pada Skala Semi Pilot||Oil spill bio-elimination on semipilot scale (500 l) was studied by applying of soil enrichment culture to degrade diesel oil, which was used as a model of oil spill. Experiment was performed at room temperature (28°C) and pH 7 in a cylinder bioreactor made of polypropilen container with effective volume of 400 liter. A compressor was used for oxygen supply to have dissolved oxygen of about 8 mg/l. Meanwhile to support the growth of microorganism, nitrogen source was added to have ratio about C/N = 1/15, in addition of 3 % NaCl as simulation for sea water. Reduction of oil concentration was monitored by extraction of oil disolving in medium microscope observation during incubation.It was shown that oil concentration was eliminated from 20.000 mg/l to 266, 25 mg/l . during 72 days incubation and acidity medium was changed to pH 3-4. Microscope observation demonstrated that microbial population were dominated by rod-shape bacteria and fungi.|
|Masno Ginting, Muljadi, Perdamean Sebayang||Pembuatan Magnet Permanen Isotropik Berbasis Nd-Fe-B dan Karakteristiknya||Fabrication and characterization of permanent magnet isotropic base on Neodymium Iron Boron (Nd-Fe-B) with composition Nd = 33,20 % weight, Fe = 65,87 % weight, B = 0,93 % weight by powder technique with firing at 700°C without oxygen has been made. Powder of alloy Nd-Fe-B was formed into tablet form and followed by sintering process at 900°C ,and 1000°C without oxygen. Characterization that has been made to all samples are phase analysis with X-Ray Diffraction, measurement of physical characteristics ( density and porosity ), and magnetics flux density using gaussmeter. Characterization with X-Ray, powder of alloy Nd-Fe-B that having the dominant phase is Nd2Fe14B with minor phase of α-Fe . After sintering process , the diffraction pattern remain the same as before . The sample highest density of 6,05 g/cm3 , porosity of 11,22 %, and magnetic flux density of 470 gauss was obtained at sintering temperature of 1000°C.|
|Rustini S Kayatmo, Yuyu Wahyu, Mohamad Haris Fathina||Perancangan dan Pembuatan Power Combiner pada Rentang Frekuensi 470 MHz – 862 MHz||Power combiner is an important subsystem of transmitter equipment. It is used to combine two power input from the input port . It requires a certain technical specification such as the insertion loss should be very low, while the isolation between ports should be very high.
In this research a power combiner in the frequency band 470 MHz – 862 MHz is designed. This frequency band is intended to be used in the UHF TV transmitters. Wilkinson method is applied and microstrip technology is implemented. Theoretical design is optimised using Ansoft Designer Student Version software.
From the measurement, maximum return loss of the power combiner at –16.389 dB is obtained, this figure is lower than it is ascertain in the design which is –16 dB. Maximum return loss in the output port is –17.726 dB. It is higher than it is ascertain in the design specification which is –18 dB. VSWR in the input port is 1.357:1, lower than the value in the design specification which is 1.3767:1, VSWR in the output port is 1.299 : 1, higher than the value in the design specification which is 1.28805 : 1. The maximum insertion loss is 0.1472 dB, lower than in the design specification which is 0.2 dB. Isolation between ports is 18.679 dB, higher than the value in the design specification which is 17 dB. It can be concluded that this design is applicable.
|Tri Admono, Pudji Irasari||Analisis Prototipe Sarana Uji Motor DC||This paper discusses the research activity on constructing test equipment for DC motor which is going to be integrated in an electric vehicle. The parameters measured are: voltage, current, rotation and temperature. The measurement method for current a 5Ω resistance is used, for rotation an optocoupler is used and for temperature an NTC is used. The performance of the prototype is tested in the laboratory by performing measurement of parameters of a fan’s motor and the result is presented in the form of RPM as a function of voltage.|
|Pudji Irasari, Nurafni Dwi Hidayati||Analisis Prototipe Generator Kecepatan Rendah untuk Pembangkit Listrik Skala Kecil||This paper discusses the result of “Construction of Low Speed Generator for Small Scale Power Plant” research. The purpose of this research is to lower or even to omit the losses of mechanical transmission system. The rotation of generator is designed to be low to meet wind turbines or low head water turbines speed. The specification of generator is 3 kW, 220 V, 12 poles, 500 rpm, with permanent magnet of Barium Ferrite with flux density of 600 Gauss. The calculation is done using MS Excel. Most of the main components are made at the Research Center for Electrical Power and Mechatronics, including rotor, shaft, and casing, whereas the stator is obtained from the market. The permanent magnet is made in collaboration with Research Center for Electronics and Telecommunication of LIPI. The design is validated by testing the prototype and analyzed to know the generator performance.|
Penulis : Ambar Susilorukmi, L Sriwuryandari, T Sembiring, MR Djuwansah, Ida Narulita, Lies Sriwurandari, Ambar Susilorukmi, Masno Ginting, Muljadi, Perdamean S, Rustini SK, Yuyu Wahyu, Mohamad Faris Fathina, Tri Admono, Pudji Irasari, Pudji Irasari, Nurafni Dwi H
Dewan redaksi : Dewan Redaksi: Totok M. S. Soegandi (Ketua), Tarzan Sembiring (Wakil Ketua), Dyah Hardini (Sekretaris). Anggota: Mochmad Ichwan, Supartono S, Iip Syarif Hidayat, Adiseno, Tigor Nauli, Elan Djaelani, Linar Zalinar Udin, Anny Sulaswatty, Adrin Tohari, Heru Santoso, Kreshna Amurwabumi, Masno Ginting, Rudy Subagja. Redaksi Pelaksana: Agusto W. Martosudirdjo, Kamaludin, Euis Setiawati, Siti Kania Kushadiani, Nanik Supriyanti.
ISSN : 0126-1533
Tahun Penerbitan : 2006
Penerbit : LIPI PRESS