Judul: Oil Palm Exocarp and Empty Fruit Bunches Based Material for Food Preservatives and Hazardous Ingredients Detector
Abstrak: Penelitian menggunakan kulit buah sawit (EBS) belum banyak dilakukan dibandingkan dengan tandan kosong kelapa sawit (TKKS). Penelitian ini dilakukan untuk mengekstraksi kandungan senyawa antosianin yang terdapat pada EBS dan mempergunakan nanoselulosa tersebut sebagai pendeteksi bahan berbahaya dan pengawet yang umumnya ditemukan dalam produk makanan (BPMB). Antosianin dari EBS diekstraksi menggunakan pelarut Metanol 96%-HCl 1%, sedangkan isolasi selulosa menggunakan metode Alkali Hidrogen Peroksida-Asam Perasetat. Selulosa dikonversi menjadi selulosa nanokristal (CNC) melalui metode hidrolisis asam sulfat dengan bantuan gelombang ultrasonikasi. Uji deteksi kandungan BPMB menggunakan formalin, boraks, dan sodium nitrit yang di variasikan dari konsentrasi 10-100.000 ppm. Hasil penelitian menunjukkan rendemen isolasi CNC diperoleh sebanyak 12,31%. Terjadi perubahan morfologi, peningkatan derajat kristalinitas, sifat termal, dan gugus fungsi akibat perubahan komponen kimia dalam serat TKKS. Deteksi terbaik ditunjukkan pada bahan sodium nitrit 10 ppm, boraks 500 ppm, dan formalin 500 ppm. Sementara itu, penambahan CNC mampu meningkatkan efektivitas deteksi bahan pengawet berbahaya kecuali pada boraks., Research on using the palm fruit exocarp (PFE) has yet to be carried out to a greater extent than the empty palm fruit bunches (EFB). In this research, anthocyanin of the PFE was used along with the EFB nanocellulose as a detector for preservatives and hazardous substances commonly found in food products (FPHS). Anthocyanins were extracted from PFE waste using a 96% HCl - 1% methanol solution, and cellulose was isolated from EFB using the alkali hydrogen peroxide-peracetic acid. The extracted cellulose was then converted into nanocrystalline cellulose (CNC) by ultrasonic assisted-hydrolysis. The FPHS used for detection sensitivity was formalin, borax, and sodium nitrite at concentrations varied from 10-100,000 ppm. The results showed that the isolation yield of CNC was 12.31%. The morphology of the cellulose and CNC were changed. Changes in functional groups and increased crystallinity and thermal properties were also found. Anthocyanin and CNC systems effectively detected the 10 ppm sodium nitrite, 500 ppm borax, and 500 ppm formalin. Meanwhile, CNC addition increased the detection sensitivity, except for borax.
Keyword: anthocyanin, food preservative, nanocellulose, oil palm

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: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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