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Kajian Pemanfaatan Eceng Gondok (Eichornia crassipes) Sebagai Pakan Ternak Itik Alabio (Anas platyrhynchos Borneo)
Full text linkAn efficient feeding strategy is utilizing abundant and nutritious local resources for livestock. Fermented hyacinths can be used as a substitute feed for ducks, which are widely available in natureand still not well utilized. On the other hand, water hyacinth also has a fairly good nutritional content to serve as a ducks feed intake. The purpose of this study is to determine the effect of feed consisting of water hyacinth fermentation to the growth of Alabio ducks. The results obtained were feed with 75% concentration of fermented hyacinths giving the best result for Alabio duck growth when compared with duck given commercial feed
COMPOSITION, STRUCTURE, CORRELATION AND LOCAL WISDOM OF ULIN (Eusideroxylon zwageri Teijsm. & Binn.) IN TAU LUMBIS- NORT BORNEO
Full text linkThe species of iron wood or locally known as ulin/tahas, is recognized as strong and durable. This study aims to provide information about condition and corelation of iron woods in natural forests of Tau Lumbis area, including its utilization and conservation through local knowledge of Dayak Akolod and Tagol tribes. The study was conducted in natural forests in Kabungolor and Kabalob (North Kalimantan). It used a plot and selected ulin tree as the midpoint of the plot. Each trees with diameter > 10 cm in the plot were measured for its stem circumference at ±1.3 m from the ground. There were 13 individuals/ha of ulin trees in Kabalob plot and 25 individuals/ha of ulin trees in Kabungolor plot (an average of ±19 individuals/ha). Based on the density measurements, there were no correlation between ulin tree and other trees species in the two locations. The iron woods were used for various needs from generation to generation by the Dayak Akolod and DTagol tribes without paying much of attention to its conservation
PERILAKU KOROSI ATMOSFER BAJA GALVANIS SETELAH EKSPOS SINGKAT DI PELABUHAN RATU, JAWA BARAT
Full text linkStudi korosi atmosfer baja galvanis dilakukan di daerah pantai Pelabuhan Ratu, Jawa Barat, dimana diatur waktu ekspos hingga 76 hari. Perfoma ketahanan korosinya ditentukan dengan metode kehilangan berat. Morfologi permukaan, komposisi unsur dan senyawa produk korosi baja galvanis diamati dengan menggunakan scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-Ray diffraction (XRD). Faktor lingkungan udara yang mempengaruhi proses korosi dimonitoring selama ekspos antara lain kelembaban relatif, suhu udara, suhu embun dan salinitas udara. Berdasarkan hasil, nilai laju korosi material adalah 0,64 mpy di waktu ekspos 27 hari dan 0,12 mpy di 76 hari. Prediksi umur pakai lapisan seng baja galvanis adalah 18 tahun. Kombinasi waktu basah dan kering bergantian ditandai dengan fluktuasi kelembaban udara dan suhu menciptakan lapisan protektif kusam dan kelabu seiring peningkatan waktu ekspos. Keberadaan klorida sebagai pemercepat reaksi korosi kurang berperan, dikarenakan kadar salinitas yang kecil. Fasa produk lapisan seng adalah zincite (ZnO) dan hydrozincite (Zn5(CO3)2.(OH)6) dimana lapisan tersebut sangat protektif untuk serangan korosi berlanjut
Electrochemical Performance of Li4-xTi5CuxO12 for Lithium Ion Capacitor Applications
Full text linkLithium titanat (LTO) has attracted considerable attention since it has unique characteristics for energy storage application. Doped LTO is one of approach to improve LTO performance. To date, doped LTO performance in full cell lithium ion capacitor has rarely been discussed. This study is aimed to synthesize Cu-doped LTO via solid state reaction and high energy milling and investigate its electrochemical performance in full cell of lithium ion capacitor. Cu-doped LTO is synthesized via solid state method with high energy milling. Diffraction pattern exhibit that Cu-doped LTO has been successfully synthesized even some impurities such as Baddeleyite, ZrO2, and Li2O appear in each sample. Cyclic voltammogram profile of half-cell based Cu-doped LTO shows that the oxidation and reduction peaks are declined due to its impurities contain. electrical resistance of LTO and Cu-doped LTO becomes smaller as increasing dopant contain while charge transfer resistance is higher. Full cell performance of LIC represent that undoped LTO//Activated carbon shows higher capacitance, namely 430 µFg-1 at specific current of 50 mAg-1than that of 2.5%-Cu-doped LTO//AC holds 15 µFg-1
COMPARISON OF RAYLEIGH WAVE CHARACTERISTICS ON SUPERCONDUCTING GRAVIMETER AND SESIMOMETER LHZ RECORDINGS
Full text linkThe vibrations of an earthquake can be properly recorded by the gravimeter. As a Gravimeter, Superconducting Gravimeter (SG) has a very high accuracy; slightly different with general gravimeter. Rayleigh wave is the wave with the largest amplitude in earthquake, so it will be clear on SG tape. In this research, we use certain superconducting gravimeter (SG) and Seismometer LHZ, spread over several locations around the world; just to know more about Mw > 6 earthquake. Tidal value reduction were applied on SG’s recording in order to get true gravity value. Then we did time-integral to get velocity and displacement. By using spectrogram function, we can display frequency of SG and LHZ. The amplitude of the Rayleigh wave recorded on the SG is smaller than that recorded on the LHZ and has signal correlation > 7.0. In any case of Rayleigh Global waves, SG is able to record clearly the phase of Rayleigh wave to R7 phase. While LHZ only records up to the R5 phase. The spectrograph analysis reinforces the differences in the viewing screens of SG and LHZ Rayleigh Global waves in the frequency domain, R7 recorded on SG has a frequency range of 0.002 Hz to 0.006 Hz. Based on the results of Rayleigh wave analysis on the SG record and its comparison with the LHZ record it can be concluded that SG has a high level of sensitivity and stable when recording Rayleigh waves
INFLUENCE OF CARBON AND NITROGEN ADDITION ON THE CORROSION RESISTANCE OF Co-28Cr-6Mo-0,8Si-0,8Mn-0,4Fe-0,2Ni ALLOYS
Full text linkCobalt alloys is one of the implant materials that is used in orthopedic and dentistry, because of its biocompatibility, good mechanical properties, and high corrosion resistance. The mechanical properties and corrosion resistance can be enhanced by thermomechanical treatment and addition of alloying element. Carbon and nitrogen were added to enhance mechanical properties and high corrosion resistance. Effect of carbon variation and nitrogen to the corrosion resistance in Co-Cr-Mo (CCM) alloys were measured by corrosion measurement system (CMS) device in Hank’s Solutions after thermomechanical treatment process. Corrosion rate of Co-Cr-Mo alloys with carbon variation dropped to 5.8 x 10-4 mmpy and 5.2 x 10-4 mmpy with carbon variation and nitrogen. Decreasing corrosion rate indicated that the corrosion resistance of alloys is increased with the addition of carbon and nitrogen
EFFECT OF HEAT TREATMENT TEMPERATURE ON MICROSTRUCTURE CHARACTERISTIC AND HARDNESS PROPERTIES OF CASTED Ti-6Al-4V ELI
Full text linkTi-6Al-4V Extra Low Interstitial (ELI) alloys have been widely used for biomedical application as implant materials due to its excellent mechanical properties and good corrosion resistance. Furthermore, mechanical properties of this alloy could be improved by heat treatment process. In this research, it has been studied the effect of heat treatment temperature on microstructure and hardness properties of casted Ti-6Al-4V ELI alloy. After calculation of material balance to obtain this alloy composition, raw materials were melted using single arc melting furnace flowed with argon gas and melted alloy was casted. Then, it was heat treated by solution treatment for around 1 hour and subsequently quenched in water as medium. Solution temperature was given with temperature variables of 850oC, 950oC and 1050oC. After that, it was aged at temperature of 500oC for 4 hours. Microstructures were observed using optical microscope and hardness value were obtained by Vickers hardness method. The results of microstructure observation showed that it was changed after heat treatment process, especially on morphology of α and β phase. Thus, the hardness of alloy significantly increased compared with as-cast condition after heat treatment process. The optimum value of hardness was obtained at temperature of 850oC that was 478 HVN.
SOLVENT EXTRACTION PROCESS FOR THE RECOVERY COBALT AND NICKEL FROM LOW-GRADE LATERITE USING BATCH RECYCLE SYSTEM
Full text linkLow-grade laterite which contains nickel lower than 0.5 % is difficult to beprocessed using pyrometallurgy. One method which isable to solve this problem is solvent extraction. In thisstudy, a solvent extraction process using batch recycle methods has been successfully applied to separate nickel and cobalt from low-grade laterite. Sulphuric acid was used to leach laterite at atmospheric pressure. Meanwhile, cyanex in toluene was used as an organic solvent. Taguchi experimental design has been used to analyze and optimize the solvent extraction process using batch recycle methods. Taguchi analysis results show that the optimum conditions are at 7 of pH, 3 hours of time operation, 0.9 liter/minute of flow rate and 0.75 of organic/aqueous solutions ratio.
HUBUNGAN ANTARA NERACA AIR LAHAN TERHADAP PRODUKSI KARET KLON BPM24
Full text linkSecara umum produksi karet dipengaruhi oleh fluktuasi curah hujan setiap bulan. Penelitian bertujuan mengetahui pengaruh curah hujan, evapotranspirasi, dan ketersediaan air lahan terhadap produksi karet klon BPM 24. Penelitian ini dilaksanakan di Kebun Percobaan Balai Penelitian Sembawa, Sumatera Selatan dari tahun 2013 – 2015. Plot penelitian yang digunakan adalah tanaman menghasilkan klon BPM 24 tahun tanam 2002 berumur 14 tahun dengan tekstur tanah clay loam. Penelitian ini dilakukan dengan cara membandingkan produksi tanaman karet pada saat musim hujan dan musim kemarau dari tahun 2013-2015. Hasil penelitian menunjukkan bahwa kadar air tanah merupakan parameter yang paling berpengaruh terhadap hasil lateks tanaman karet klon BPM 24 dibandingkan dengan parameter curah hujan dan evapotranspirasi. Hasil lateks menurun dengan berkurangnya kandungan air tanah pada periode bulan kering. Kurangnya air pada bulan kering menjadi faktor pembatas untuk hasil karet yang optimal. Ketika kadar air tanah turun hingga di bawah 100 mm, hasil lateks maksimal yang dapat dicapai oleh tanaman karet adalah sebesar 20 g/p/s