Judul: Penentuan Titik Kritis Susut Pascapanen Pisang Ambon (Studi Kasus Sentra Produksi Pisang Kabupaten Pesawaran Lampung)
Abstrak: Kehilangan pascapanen buah-buahan di negara berkembang 20-50%, salah satunya yaitu buah pisang. Kehilangan pascapanen utamanya akan merugikan secara ekonomi. Oleh karena itu perlu adanya kajian dan identifikasi tentang kehilangan hasil (susut) pisang agar diketahui tingkat rantai pasok yang mempunyai susut terbesar beserta penyebabnya. Sehingga jumlah kehilangan dapat dikurangi dengan rekomendasi teknis berupa intervensi teknologi dan perbaikan GHP (Good Handling Practice) berdasarkan penyebab yang telah diketahui. Tujuan dari penelitian ini adalah mengidentifikasi jalur distribusi dan proses penanganan pascapanen buah pisang di sentra produksi pisang di Pesawaran, menelaah kehilangan hasil buah pisang, baik kehilangan kuantitatif (volume/jumlah), kehilangan kualitatif (mutu), dan kehilangan ekonomi (nilai/harga), menentukan titik kritis susut pascapanen pisang ambon, dan mengetahui kelayakan usaha tani pisang ambon dan pada rumah pengemasan pisang ambon berdasarkan susut dan input produksi petani. Penelitian dilakukan di seluruh tingkatan pasok mulai dari sentra produksi yang berada di kabupaten Pesawaran Lampung hingga ke pasar modern dan pedagang ecer di daerah Jabodetabek. Penarikan sampel pada tiap tingkatan pemasaran dilakukan dengan sengaja (purposive) berdasarkan kesamaan proses. Pengambilan data melalui pengamatan secara langsung, wawancara, dan pengukuran. Analisis data yang digunakan analisis deskriptif dan analisis teknis. Kabupaten Pesawaran merupakan salah satu sentra produksi pisang di Indonesia yang potensial. Produktivitas pisangnya menjadikan provinsi Lampung menempati urutan keempat produksi pisang nasional tahun 2010. Pisang dipanen oleh petani kemudian dijual ke pengumpul kecil. Selanjutnya pengumpul kecil menjual ke pengumpul besar. Pada tingkat inilah dilakukan penanganan pascapanen secara manual seperti pengumpulan, penyisiran, pencucian, grading, sortasi, dan pengemasan. Rantai pasok selanjutnya yaitu perusahaan yang sudah menerapkan sistem rantai dingin sejak buah diperam. Kemudian dilanjutkan ke pasar grosir dan pengecer, atau super market. Kehilangan kuantitatif, kualitatif, dan harga di tingkat petani dan pengumpul kecil adalah 0. Susut kuantitatif di tingkat pengumpul besar 3.1%, susut kualitatif 9.74%, dan susut harga 82.61%. Susut kuantitatif di tingkat perusahaan 0.77%, susut kualitatif 5.99%, dan susut harga 20.69%. Susut kuantitatif di tingkat pasar grosir tidak ada. Harganya rata-rata turun sebesar 41,75% dengan jumlah pisang yang mengalami penurunan harga tersebut sebesar 15.67%. Susut kuantitatif di tingkat pengecer 6.66%, susut kualitatif 23.42%, dan susut harga 53.66%. Susut kuantitatif di pasar modern 10-15%, susut kualitatif 20-25%, dan susut harga 25-50%. Titik kritis kehilangan pascapanen terjadi di tingkat petani dan pengumpul kecil yang merupakan pangkal dari rantai distribusi pisang sehingga sangat mempengaruhi kualitas buah di tingkat-tingkat selanjutnya. Proses pemanenan oleh petani dan penyimpanan oleh pengumpul kecil belum menggunakan cara penanganan pascapanen yang baik sehingga kehilangan hasil dan penurunan kualitas buah pisang di tingkat setelahnya cukup tinggi. Titik kritis yang lain adalah tingkat pengecer, dimana kondisi pisang telah masak penuh dengan indek warna 5-6. Pada tingkat ini buah sangat rentan terhadap kerusakan dan terjadi penurunan tingkat kekerasan sehingga memerlukan penanganan pascapanen yang baik. Berdasarkan analisa kelayakan yang didapatkan dari hasil perhitungan analisis usaha tani pisang dan pada rumah pengemasan pisang adalah layak untuk dijalankan karena menghasilkan tingkat keuntungan tertentu. Nilai BC Ratio lebih besar dari satu, yaitu 1.93 dan nilai NPV adalah positif.
Keyword: Losses, Postharvest, Banana, Supply Chain

Judul: Penentuan Titik Kritis Susut Pascapanen Pisang (Studi Kasus Sentra produksi Pisang Kabupaten Cianjur)
Abstrak: Postharvest handling of tropical fruits is still the major problem in Indonesia due to lack of facility and knowledge of the farmer. This condition has caused the losses both in quatity and quality of fruits during distribution from the production centre to the market. Some researchers reported that total postharvest losses of tropical fruits in developing countries is 20-50%. However, no available data shows in which postharvest handling point and who is the actor take responsibility. The objectives of this study were to investigate the losess in postharvest handling of banana in supply chain, to measure the value of losess of postharvest handling in each actors, to identify the cause of postharvest handling losses and to analyze the efficiency of marketing in supply chain of banana. This study was conducted in banana central production in Cianjur. The results show that there were three marketing channel in supply chain of banana in central production Cianjur. First channel was Farmers – collector - Retailer - Consumer). Second channel was Farmers - Collectors – wholesaler - Retailer - Consumer). Third channel was Farmers – village collector – Big collector – Supermarket - Consumer. Quantitatively, the critical point of banana postharvest handling in the first channel was occured in collector i.e. 10.90% with total losses was 15.25%. For second channel, totall losses was 16.77% with the highest losses occured at village collector level i.e. 8.44%. For third channel, total losses was 39.30% with the highest losses occured at supermarket i.e. 32.13%. Qualitatively, for the first channel, losses postharvest handling of banana was 23% where all losses occured in the level of trader. The second channel, total losses was 57.73% with the highest losses occured in village collector level i.e. 48.96%. For third channel, total loss was 49.96% and the highest losses occured in the big collector level i.e. 29.36%. Among the channels in the supply chain of banana in central production of banana in Cianjur, the first channel was identified as the most efficient channel due to lower margin in trading which providing the biggest farmer's share. The cost benefit ratio in first channel was also higher than those second and third channel.
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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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