Judul: Perubahan Mutu dan Masa Simpan Cabai Katokkon (Capsicum annuum var. chinensis) dalam Berbagai Suhu Penyimpanan
Abstrak: Cabai katokkon memiliki laju penurunan mutu yang tinggi akibat peningkatan proses respirasi dan transpirasi jika disimpan dalam suhu ruang. Alternatif penanganan diperlukan untuk menekan penurunan mutu selama penyimpanan. Alternatif yang dapat digunakan adalah penyimpanan dingin. Tujuan penelitian ini adalah menganalisis pengaruh suhu penyimpanan terhadap mutu dan umur simpan cabai katokkon. Tahapan penelitian terdiri dari persiapan sampel, penyimpanan dalam suhu 5 °C, 10 °C, 15 °C dan suhu ruang (27 – 31 °C), pengukuran parameter mutu, serta pendugaan umur simpan. Parameter mutu yang diukur yaitu kadar air, nilai kekerasan, perubahan warna, dan tingkat kerusakan. Pendugaan umur simpan dihitung menggunakan metode Arrhenius dengan persamaan k = 19717162,36 e^-5803,8(1/T). Hasil penelitian menunjukkan penyimpanan cabai katokkon dalam suhu 5 °C menghasilkan rata-rata nilai kadar air tertinggi (91,32 %), nilai kekerasan tertinggi (0,51 kgf), laju kerusakan terendah (1,25 %/hari), dan dapat mempertahankan warna dan kecerahan cabai katokkon paling baik. Penyimpanan suhu ruang menghasilkan rata-rata nilai kekerasan terendah (0,44 kgf), laju kerusakan tertinggi (7,94 %/hari) dan dapat mempertahankan warna dan kecerahan cabai katokkon paling buruk. Penelitian ini menunjukkan bahwa penyimpanan cabai katokkon dalam suhu 5 °C memberikan hasil terbaik dalam memperpanjang umur simpan, menekan laju kerusakan, penurunan kadar air, nilai kekerasan, dan perubahan warna., Katokkon chili has a high rate of deterioration due to an increase in the process of respiration and transpiration when stored at room temperature. Alternative treatment is needed to reduce quality loss during storage. An alternative that can be used is cold storage. The purpose of this study was to analyze the effect of storage temperature on the quality and shelf life of katokkon chili. The research stage consists of sample preparation, storage at temperatures of 5 °C, 10 °C, 15 °C and room temperature (27 – 31 °C), measurement of quality parameters, and estimation of shelf life. The quality parameters measured are water content, hardness value, color change, and rottenness level. Estimation of shelf life calculated using the Arrhenius method with the equation k = 19717162,36 e^-5803,8(1/T). The results showed that the storage of katokkon chili at a temperature of 5 °C resulted in the highest average water content value (91.32 %), the highest hardness value (0.51 kgf), the lowest rottenness rate (1.25 %/day), and can maintain the color and brightness of the katokkon chili the best. Storage at room temperature resulted in the lowest average hardness value (0.44 kgf), the highest rottenness rate (7.94 %/day) and the worst color and brightness of katokkon chilies were maintained. This study showed that the storage of katokkon chili peppers in a temperature of 5 °C provides the best results in extending shelf life, suppressing the rate of rottenness, decreased moisture content, hardness value, and color changes.
Keyword: katokkon chili, quality, shelf life, storage, temperature

Judul: Respon kualitas pascapanen Cabai Merah (Capsicum annum L.) terhadap suhu penyimpanan
Abstrak: Penelitian ini bertujuan untuk menganalisis pengaruh suhu penyimpanan terhadap kualitas cabai merah, menentukan suhu penyimpanan yang optimum untuk mempertahankan kesegaran dan mutu cabai merah segar serta menganalisis karakteristik cabai merah segar pada penyimpanan suhu rendah. Parameter mutu yang diuji adalah laju repirasi, kadar air, susut bobot, kekerasan, warna, total padatan terlarut (TPT), vitamin C, dan capsaicin. Penyimpanan pada suhu 10 °C mampu mempertahankan mutu cabai lebih baik. Pada suhu 10°C cabai mengalami penurunan sudut hue sebesar 10.36°, peningkatan TPT sebesar 4.46 °Brix, penurunan vitamin C sebesar 172.09 mg/100 g, penurunan kekerasan sebesar 1.408 N dengan diameter probe 2.5 mm, dan penurunan capsaicin sebesar 1227.36. Pada suhu 15 °C cabai mengalami penurunan sudut hue sebesar 9.05°, peningkatan nilai TPT sebesar 3.9 °Brix, penurunan vitamin C sebesar 60.09 mg/100 g. penurunan kekerasan sebesar 1.474 N dengan diameter probe 2.5 mm, dan penurunan capsaicin sebesar 859.84. Sedangkan pada penyimpanan suhu ruang (27-30 °C) kurang mampu mempertahankan mutu cabai. Pada suhu ruang cabai mengalami penurunan sudut hue sebesar 27.25°, peningkatan TPT sebesar 9.033 °Brix, penurunan vitamin C sebesar 58.09 mg/100 g, penurunan kekerasan sebesar E18 N dengan diameter probe 2.5 mm, dan peningkatan capsaicin 2027.52 SHU….
Keyword: Chili, Quality, Storage temperature, Temperature, Agricultural maching, Capsicum annum L.

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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