Judul: Analisis Biaya-Manfaat Perusahaan Pengelola Limbah Bahan Berbahaya dan Beracun (B3) dan Skenario Pengelolaan yang Efektif
Abstrak: The deferment of hazardous wastes management caused by its huge costs become an opportunity for the growth of hazardous wastes utilization and processing services industry. The number of this industry is quite small in Indonesia, therefore this research is trying to know further about the economic feasibility of these wastes management services activities by using benefit and cost analysis, and evaluating its response by changing the possiblity on quantity of wastes changes. It is obtained that these activities would be returned in the 8th year since it is started, with the number of NPV to be Rp 110 997 445 852, IRR to be 17% and Net B/C to be 3 by benefit and cost analysis, so it is feasible to be developed further. It needs to be considered when there is a decrease in number of entry wastes which are more than 30%. The existance of this industry become an alternatif to solve hazardous management problems. By using cost effectiveness analysis, it can be decided which one is the best sollution, wheter wastes should be handled autunomusly/being utilized or by using these services. In limited budgeting condition of fly ash wastes management, handled by these services is more effective because when it is utilized to be paving block its cost is 2,14 times bigger, but in unlimited budgetting condition, utilizing those to be paving block is profitable. Cost ratio for paper sludges which are handled by these services is 8.85 bigger than handled autonomously by utilized to be low grade paper. Handling the number of solvent wastes which are less than 60 liters/day by these services is more effective than investing an purifier machine because its investing cost is 1.022 times bigger, but when it is more than 60 liters/days, the cost ratio for handled by these services is 3,26 times bigger. It is costly more effective to use these services for about 1-1177 kg/day and 1281-4007 kg/day while investing an incinerator is cheaper for 1178-1280kg/day and for more than 4007 kg/day medical wastes management
Keyword: solvent,, paper sludge treatment, medical waste, hazardous wastes management, fly ash, cost effectiveness, Bogor Agricultural University (IPB)

Judul: Financial Feasibility and Sustainability Analysis of Waste Bank (Case Study: Gesit Main Waste Bank, South Jakarta)
Abstrak: Peningkatan jumlah penduduk yang diiringi dengan pertumbuhan ekonomi, peningkatan kesejahteraan masyarakat, dan urbanisasi menyebabkan jumlah timbulan sampah meningkat dengan cepat. Pemerintah Jakarta Selatan bersama dengan masyarakat peduli lingkungan membangun Bank Sampah Induk Gesit (BSI Gesit) untuk mengakomodasi pengelolaan sampah dan mereduksi jumlah (TPST) Bantargebang melalui pengelolaan sampah yang berkelanjutan secara manajemen, ekonomi, lingkungan, dan sosial. Penelitian ini bertujuan untuk (1) mengidentifikasi kendala pengelolaan bank sampah, (2) mengestimasi kelayakan usaha bank sampah, serta (3) merekomendasikan strategi kebijakan pengelolaan sampah di BSI Gesit. Metode analisis yang digunakan pada penelitian ini adalah analisis deskriptif, analisis kelayakan finansial, dan analisis strategi keberlanjutan dengan PROMETHEE (Preference Organization Method for Enrichment Evaluation). Hasil penelitian menunjukkan bahwa transisi pengelolaan sampah subsidi menjadi mandiri menghadapi kendala pada sumber penerimaan, ketersediaan sarana pengangkut dan tenaga kerja, serta ketersediaan supply dari bank sampah unit. Hasil analisis kelayakan finansial usaha BSI Gesit menunjukkan bahwa skenario I yaitu pengelolaan mandiri dan skenario IV yaitu business as usual (BAU) layak dijalankan karena memenuhi seluruh kriteria kelayakan finansial, sedangkan skenario II yaitu pengelolaan bantuan 50% untuk biaya operasional dan skenario III yaitu subsidi upah tenaga kerja tidak layak dijalankan. Pada analisis strategi keberlanjutan, pengelolaan bank sampah yang dapat diprioritaskan adalah alternatif I yaitu pengelolaan mandiri dengan peningkatan penerimaan sebesar 15% setiap tahunnya berdasarkan kontribusi positif dari seluruh kriteria pada dimensi keberlanjutan yaitu manajemen, ekonomi, lingkungan, dan sosial., The increase in population accompanied by economic growth, increased social welfare, and urbanization will inflict the amount of waste production to increase rapidly. The South Jakarta Government along with environment activist from local community established Gesit Main Waste Bank to accommodate the city’s waste management and to reduce the load of waste management in TPST Bantargebang by implementing sustainable waste management that requires consideration of management, economic, environment, and social dimensions. This study aims to (1) identify the constraints of waste bank management, (2) estimate the feasibility of a waste bank, and (3) propose a policy strategy for waste management at BSI Gesit. This study employs descriptive analysis, financial feasibility analysis, and sustainability policy analysis using PROMETHEE (Preference Organization Method for Enrichment Evaluation). This study demonstrates that the transtition of subsidized waste management to independently managed waste bank will encounter the lacking of revenue sources, the supply availability from unit waste bank, and the availability of labor and transport facilities. Financial feasibility analysis shows that the first scenario which managed independently without subsidies and the forth scenario (BAU) are feasible because it meets all financial feasibility criteria. On the other hand, the second scenario with half assistance for operational cost and the third scenario with subsidies for labor wage are not feasible. The policy alternatives that need to be prioritized from PROMETHEE analysis are alternative I (independent optimization) based on the consideration of positive contribution from all sustainability criteria, namely management, economic, environmental, and social dimensions.
Keyword: analisis finansial, pengelolaan sampah, reduksi sampah, strategi keberlanjutan

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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