Judul: Analisis Persepsi Nasabah dan Manfaat Ekonomi Pengelolaan Bank Sampah (Studi Kasus : Bank Sampah Malaka Sari, Jakarta Timur)
Abstrak: Salah satu alternatif dari pengelolaan sampah berbasis masyarakat yang dilakukan pemerintah adalah program bank sampah. Program ini diharapkan dapat meningkatkan kesadaran masyarakat akan pentingnya lingkungan hidup yang bersih dan sehat serta dapat membuat sampah menjadi barang yang memiliki nilai ekonomi. Bank Sampah Malaka Sari merupakan Bank Sampah pertama yang terdapat di DKI Jakarta dan merupakan bank sampah yang mengalami penutupan sementara untuk mengurangi penyebaran virus COVID-19 pada tahun 2020. Penelitian ini bertujuan untuk menganalisis persepsi nasabah aktif menggunakan analisis skala likert, mengestimasi manfaat ekonomi menggunakan analisis pendapatan, mengestimasi besaran share pendapatan nasabah aktif dengan analisis deskriptif. Hasil penelitian menunjukan bahwa persepsi nasabah aktif terhadap pengelolaan Bank Sampah Malaka Sari sangat baik. Manfaat ekonomi yang dihasilkan dari pengelolaan Bank Sampah Malaka Sari bernilai positif, yaitu pada tahun 2019 sebesar Rp 5.421.303 dan tahun 2020 sebesar Rp 2.762.758. Besaran share pendapatan yang dihasilkan nasabah dari menabung di bank sampah setiap bulan pada tahun 2019 1,33% dan tahun 2020 sebesar 1,11%, persentase ini menurun karena operasional Bank Sampah Malaka Sari berhenti sementara karena pandemi COVID-19., Waste bank program is one of the communit based waste management system. This program is expected to increase public awareness of the importance of a clean and healthy environment and can turn waste into goods that have economic value. The Malaka Sari Waste Bank is the first Waste Bank in DKI Jakarta and is a waste bank that is temporarily closed to reduce the spread of the COVID-19 virus in 2020. This study aims to analyze the perception of active customers using Likert scale analysis, estimate the economic benefits using analysis income, estimating the size of the share of active customers' income with descriptive analysis. The results showed that the perception of active customers on the management of the Malaka Sari Waste Bank was very good. The economic benefits generated from the management of the Malaka Sari Waste Bank are positive, amounted in 2019 is Rp. 5.421.303 and in 2020 is Rp. 2.762.758. The amount of revenue sharing generated by customers from savings in waste banks every month in 2019 was 1,33% and in 2020 by 1,11%, this percentage decreased because the operations of the Malaka Sari Waste Bank were temporarily suspended due to the COVID-19 pandemic.
Keyword: income analysis, likert scale analysis, share income, waste management

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: 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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