Judul: Analysis of the Economic Benefits of Community-Based Waste Management (Case Study: Sindara Berkah Waste Bank, Gunung Batu Village, Bogor City)
Abstrak: Bank sampah merupakan contoh strategi pengelolaan sampah yang berfokus pada konsep 3R (reduce, reuse, recycle). Salah satu bank sampah yang ada di Kelurahan Gunung Batu, Kota Bogor adalah Bank Sampah Sindara Berkah. Jumlah nasabah yang berpartisipasi di Bank Sampah Sindara Berkah dinilai masih rendah karena kurangnya kesadaran akan pentingnya mengelola sampah. Penelitian ini bertujuan (1) Mengidentifikasi sistem pengelolaan sampah di Bank Sampah Sindara Berkah, (2) Menganalisis persepsi nasabah terkait pengelolaan sampah di Bank Sampah Sindara Berkah, dan (3) Menganalisis manfaat ekonomi dari pengelolaan sampah di Bank Sampah Sindara Berkah. Metode yang digunakan pada penelitian ini adalah analisis deskriptif kualitatif dan kuantitatif, serta analisis pendapatan. Hasil penelitian ini menunjukkan sistem pengelolaan yang dijalankan oleh bank sampah masih dikategorikan sederhana. Persepsi nasabah terhadap Bank Sampah Sindara Berkah sangat baik. Hasil perhitungan dari analisis pendapatan sebesar Rp 668.800,00. Hasil akhir analisis menunjukkan bahwa keberadaan bank sampah memberikan manfaat kepada nasabah terutama nasabah Bank Sampah Sindara Berkah., The waste bank is an example of a waste management strategy with the 3R concept (Reduce, reuse, recycle). One of the waste banks in Gunung Batu Village, Bogor City is the Sindara Berkah Waste Bank. The number of customers participating in the Sindara Berkah Waste Bank is considered low due to a lack of awareness of the importance of managing waste. This study aims (1) to identify the waste management system at the Sindara Berkah Waste Bank, (2) to analyze public perceptions regarding waste management at the Sindara Berkah Waste Bank, and (3) to analyze the economic benefits of waste management at the Sindara Berkah Waste Bank. The method used in this research is descriptive qualitative and quantitative analysis, as well as income analysis. The results of this study indicate that the management system run by the bank is still categorized as simple. The public perception of the Sindara Berkah Waste Bank is very good. The result of the calculation from the income analysis is IDR 668.800.00. The final result of the analysis shows that the existence of the waste bank provides benefits to the community, especially the customers of the Sindara Berkah Waste Bank.
Keyword: likert, partistipasi,, partistipasi, pendapatan, persepsi, sampah anorganik, income, inorganic waste, likert, participation, perception

Judul: Factors Associated with Environmental, Economic  and Social Benefits of Waste Banks.
Abstrak: Bank sampah dipandang dapat menjadi salah satu solusi atas masalah sampah di Indonesia. Penelitian ini menjelaskan apakah karakteristik nasabah, tingkat kinerja pengurus dan tingkat partisipasi masyarakat merupakan faktor-faktor yang memiliki hubungan dengan manfaat yang dihasilkan bank sampah. Penelitian ini dilakukan di RW 01, Kelurahan Babakan, Kota Bogor dengan tujuan untuk menganalisis karakteristik nasabah, tingkat kinerja pengurus, tingkat partisipasi masyarakat dan manfaat yang dihasilkan bank sampah. Penelitian ini menggunakan metode campuran (mixed method). Metode kuantitatif menggunakan kuesioner sebagai alat pengumpul data dari 35 responden dan didukung dengan data kualitatif melalui observasi terlibat dan wawancara mendalam dengan informan kunci. Analisis data kuantitatif dengan menggunakan uji korelasi rank spearman mengindikasikan bahwa indikator tingkat pendidikan memiliki hubungan yang signifikan dengan indikator tahap perencanaan pada tingkat partisipasi masyarakat. Hasil uji korelasi juga menunjukkan bahwa tingkat kinerja pengurus memiliki hubungan yang signifikan dengan tingkat partisipasi masyarakat. Selain itu, tingkat partisipasi masyarakat memiliki hubungan yang signifikan dengan manfaat bank sampah, Waste banks are seen as a solution to the waste problem in Indonesia. This research explains whether customer characteristics, level of management performance and level of community participation are factors that are related to the benefits generated by waste banks. This research was conducted in RW 01, Babakan Village, Bogor City. This research uses mixed methods. The quantitative method uses a questionnaire as a data collection tool from 35 respondents. Quantitative data analysis indicates that the education level has a significant relationship with the planning stage on the community participation level. The correlation test show that the level of management performance has a significant relationship with the level of community participation. Apart from that, the level of community participation has a significant relationship with the benefits of waste banks.
Keyword: waste bank, waste bank management performance, waste bank benefits, community participations

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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