Judul: Feasibility Analysis and Economic, Social, and Environmental Impact on Mangoes Center Agrimania Mango Cultivation (Case Study: Wong Tanggul Ceblok Farmer Group, CSR Development Partner of PT Kilang Pertamina Internasional Unit VI).
Abstrak: Mangoes Center merupakan sub-program TJSL PT KPI Unit VI yang berfokus dalam pembudidayaan tanaman lokal dan telah dijalankan sejak tahun 2017. Pada tahun 2024, program ini menjadi tahun terakhir didanai biaya operasional budidaya, sehingga tahun berikutnya program akan dikelola secara mandiri oleh kelompok tani tanpa bantuan dana dari perusahaan. Tujuan dari penelitian ini yaitu: 1) Menganalisis dampak ekonomi, sosial dan lingkungan Mangoes Center terhadap kelompok tani penerima manfaat program. 2) Menganalisis kelayakan usahatani budidaya mangga agrimania bagi kelompok tani WTC. 3) Menganalisis kelayakan finansial skema tumpang sari dengan jambu kristal. Metode yang digunakan dalam penelitian ini adalah analisis deskriptif dengan benefit transfer dan market price, serta analisis biaya dan manfaat dengan kriteria kelayakan investasi (NPV, Net B/C, IRR, dan PP). Hasil penelitian menunjukkan bahwa program ini memiliki dampak positif bagi ekonomi, sosial dan lingkungan. Selain itu, usahatani budidaya mangga agrimania yang dilakukan Kelompok Tani WTC layak dilakukan berdasarkan aspek-aspek nonfinansial usahatani dan kriteria investasi di mana NPV lebih besar Rp1.160.660.203, Net B/C lebih besar 2,44, IRR lebih besar 1,86% dibandingkan NPV, Net B/C, dan IRR yang dihasilkan dari budidaya mangga agrimania monokultur., Mangoes Center is a sub-program of TJSL PT KPI Unit VI focused on cultivating local plants and has been running since 2017. In 2024, this program will be in its final year of receiving funding for operational costs, after which it will be managed independently by the farmers' group without financial assistance from the company. The objectives of this study are: 1) To analyze the economic, social, and environmental impacts of Mangoes Center on the beneficiary farmers' group. 2) To assess the feasibility of agrimania mango cultivation for the WTC farmers' group. 3) To evaluate the financial feasibility of ntercropping with crystal guava. The methods used in this study include descriptive analysis with benefit transfer and market price, as well as cost-benefit analysis using investment feasibility criteria (NPV, Net B/C, IRR, and PP). The results show that the program has a positive impact on economic, social, and environmental aspects. Additionally, agrimania mango cultivation by the WTC farmers' group is deemed feasible based on non-financial aspects of farming and investment criteria, with an NPV exceeding Rp1,160,660,203, a Net B/C ratio greater than 2.44, and an IRR higher than 1.86% compared to the NPV, Net B/C, and IRR from monoculture agrimania mango cultivation.
Keyword: benefit transfer, corporate social responsibility, cost and benefit analysis, intercropping, market price, program impact

Judul: An analysis on operational feasibility of packing house for mangosteen commodity, in hegarmanah village, Cicantayan sub-district, Sukabumi regency
Abstrak: Along with the high demand for mangosteen fruit from domestic and export, it is necessary to have a good post-harvest handling to be able to manage the sales of mangosteen products. For this purpose, Hegarmanah Village, Cicantayan Sub-district, Sukabumi Regency built a packing house called Mega Fruit (Mustika Lestari XI), which is managed by a mangosteen farmer group. In 2009 the government provided assistance in the form of a building for packing house and its facilities. To analysis whether the packing house operation with the addition of the government aid is feasible or not definitely requires research on the analysis of operational feasibility of Mega Fruit (Mustika Lestari XI).The data used in this research was obtained through interviews with managers and studies on related literature. In this study the operational feasibility analysis included financial, technical and managerial aspects. The financial aspect analysis included production cost and investment feasibility. The technical aspect analysis covered production process and material flow pattern of mangosteen products. The management analysis involved such aspects as business entity, labor division, and organizational structure. The total cost of mangosteen production was Rp 2,749,085,666. With the basic cost of Rp 8,086 / kg, it was still below the selling price of Rp 8,300 / kg, so that the sales of mangosteen could provide a profit of Rp 214 / kg. The break even point of packing house operations was 135,459 kg / year. The average production reached 340,000 kg / year, meaning that the packing house was running at a profitable level. The result of financial feasibility analysis showed that the packing house was feasible to operate with the NPV value of the project's life of (grant of packing house) nine years ahead on a discount factor of 15% Rp 192,350,661, the IRR of 32.77%, the net value B / C of 1.74, and the payback period of 3.1 years. The result of sensitivity analysis to changes in the operational costs of transportation, production volumes and selling prices at the packing house showed that the selling price was an element of change which was so sensitive that in the future the selling price should be higher. The technical analysis showed that the packing house was run by a regular sequence of production activities with the U-shaped pattern of material flow so that the desired end product was at the location adjacent to the initial process. The analysis showed that based on the management aspect of the ownership status, the packing house was owned by a group of farmers. The operational management of packing house was done by workers in line with the need so that production could run well.
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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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