Judul: Pengembangan Sistem Deteksi Kematangan Tandan Buah Segar (TBS) Kelapa Sawit Berbasis Spektrum Cahaya Tampak
Abstrak: Palm oil is one of the most famous commodities in Indonesia, seen from the growth area significantly. Since 2005, Indonesia overtake Malaysia as the largest palm oil exporter and currently holds more than 50% global market share (USDA 2012). But the problem is the crude palm oil (CPO) quality with the content of free fat acid (FFA) more than 5%, it means that FFA content more than the international standard which required less than 3%. This problem caused decreasing of the price or discount rate for CPO from Indonesia. The best harvesting time of palm oil is when the CPO maximum and FFA minimum. Harvesting of palm oil in the over maturity stage caused FFA content more than 5%, and if the harvesting of palm oil in the under maturity stage, the content of both FFA and CPO low (Fauziet al.2007). The precision of harvesting time would be very difficult if using human resources which considered on the fraction or percentage of palm oil fruits which fall in the soil surface. These human resources methods was low accuracy, it was caused by many external factors like as the fruit would be hold on the palm oil stems and in the rainy season FFB would release from the bunches before maturity stages. One of the best ways to solve these problems is using censors for maturity detection of FFB. To get the precise censor would need optical characteristics tests of palm oil FFB using Uv-Vis spectrophotometer. Resulted data from these measurements was in the reflectance characteristics from the FFB spectrum, and then these data would be used for maturity detections system of palm oil FFB. The objectives of this research are studying of FFB spectrum characteristics based on the maturity stages using visible wave reflectances method, studying about the interactions between chemical contents with visible wave spectrum of palm oil FFB, and creating oil palm FFB maturity detection system using censors, displays, and recorders. Materials used for this research are 87 palm oil FFB from the Marihat, Selapan Jaya, and Dumpy clones. Number of samples of each clone is 29 pieces consisting of four (4) level of maturity that is raw (fraction 0), less mature (fraction 1) mature (fraction 2 and fraction 3), over-mature (fraction 4). This research using ocean optics spectrometer USB 650, fiber optic solids, digital spotting scope (bushnell 15 – 45x, LCD 22x), red laser pointer (660nm, 100 mW), lux meter, halogen lamps (1000 and 6000 Watt), black fabric, distance meter, laboratory instruments for FFB chemical tests, computer and it’s components. The first step is classified of integration time with measuring white reference reflectan and black in the spesific distances of measuring. Using references was be done for standarized of measuring. FFB spectrum would be cauthed by digital spotting scope and FFB reflectances would be read by spectrometer ocean optics USB 650 (fiber optic solid) in the wave lenght 200-850 nm. To ensure the point of FFB measurement, laser pointer was used and FFB spectrum would be displayed by display in the digital spotting scope. Reading was vi be done
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Judul: Designing maturity measurement instrument of Fresh Fruit Bunch (FFB) oil palm with microcontroler
Abstrak: Estimation of FFB maturity is important point on harvesting activity. The step greatly affects the production of palm oil on production stage. If condition of FFB that is processed is not ripe or over ripe, it can reduce the yield of palm oil. This research aims to design a maturity measurement instrument of fresh fruit bunch (FFB) oil palm with microcontroller. Instrument works by identifying the intensity of reflected light that can represent the colors produced by carotenoid pigments. On palm fruit, levels of carotenoid pigments formed over the formation of fat (oil), so it will look also alleged pattern of oil content by instrument in accordance with the level of ripeness of the fruit. Results indicate that the instrument is able to provide the intensity of reflected light pattern similar to the pattern of oil content in the fruit. However, the instrument can not distinguish the level of maturity fractions only by reffering to the pattern because of the intensity values in fraction 1 to 4 adjacent and similar
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Judul: Solusi Geometri Schwarzschild untuk Dimensi 4+1 dengan Invarian Rotasi Isotropik.
Abstrak: Metrik Schwarzschild merupakan solusi eksak pertama dari persamaan medan Einstein dengan mangasumsikan metrik statik dan simetris. Metrik Schwarzschild yang ditemukan oleh Karl Schwarzschild masih dalam dimensi 3+1, namun seiring dengan teori-teori terbaru yang menunjukkan bahwa alam semesta tidak hanya di dimensi 3+1. Maka melalui penambahan dimensi, tujuan penelitian ini memperoleh solusi pada geometri Schwarzschild untuk dimensi 4+1 dengan memodifikasi koordinat bola yang invarian rotasi isotropik dan melalui penurunan rumus seperti koordinat bola, simbol Christoffel, dan tensor Ricci. Selain mendapatkan solusi ini, metrik Schwarzschild dimensi 4+1 dapat digunakan sebagai metrik dasar untuk memperoleh solusi blackhole dan wormhole pada dimensi 4+1. Hasil akhirnya, dengan memanfaatkan modifikasi koordinat bola, metrik Schwarzschild dapat dibentuk sehingga diperoleh solusi geometri Schwarzschild untuk dimensi 4+1.
Keyword: metrik Schwarzschild, persamaan medan Einstein, modifikasi koordinat bola, penambahan dimensi, invarian rotasi isotropik