Judul: The Impact of COVID-19 Pandemic on Warung Jambu Bersih Waste Bank Bogor City
Abstrak: Peningkatan timbulan sampah masih menjadi masalah di Kota Bogor sebagai dampak dari tingginya pertumbuhan penduduk dan kurangnya kesadaran masyarakat. Bank Sampah Warung Jambu Bersih telah mencoba mengambil peran dalam upaya mereduksi sampah di Kota Bogor, namun aktivitasnya harus berhenti akibat mewabahnya virus COVID-19. Tujuan umum penelitian adalah menganalisis dampak pandemi COVID-19 terhadap Bank Sampah Warung Jambu Bersih. Tujuan khusus penelitian yaitu untuk menganalisis persepsi nasabah terhadap dampak pengelolaan sampah di bank sampah, mengidentifikasi dampak pandemi terhadap bank sampah, mengestimasi perubahan nilai ekonomi sampah akibat pandemi, menganalisis keberlanjutan bank sampah, serta mengidentifikasi alternatif pengembangan bank sampah. Tujuan-tujuan tersebut dikaji dengan metode analisis deskriptif kualitatif dan kuantitatif, analisis skala Likert, dan RAPFISH-MDS. Hasil penelitian menunjukkan nasabah sangat setuju bahwa aktivitas bank sampah memberikan pengaruh positif dalam aspek sosial, ekonomi, dan lingkungan. Dampak pandemi COVID-19 terhadap keberlangsungan operasional bank sampah membawa implikasi sosial, ekonomi, dan ekologi. Nilai ekonomi sampah yang dikumpulkan nasabah pada bank sampah menurun hingga 84% akibat pandemi. Lebih jauh lagi, hasil analisis RAPFISH-MDS menunjukkan bahwa bank sampah kurang berkelanjutan. Dukungan pembinaan dan finansial dari pihak eksternal akan membantu keberlanjutan bank sampah., The increasing of waste generation is problematic in Bogor city due to high population growth and lack of public awareness. Warung Jambu Bersih Waste Bank was established to play a role in reducing the waste generation in Bogor city. However, its operation has been suspended due to COVID-19 pandemic. The general objective of this study is to analyze the COVID-19 pandemic’s impact on Warung Jambu Bersih Waste Bank. Furthermore, the specific objectives are: 1) to examine customers perceptions of waste bank; 2) to identify the pandemic’s impact on waste bank; 3) to estimate changes in economic value of waste due to pandemic; 4) to assess waste bank’s sustainability, and; 5) to identify alternatives strategy for waste bank development. Analytical methods used in this study are qualitative and quantitative descriptive analysis, Likert scale analysis, and RAPFISH-MDS. The results show that the customers strongly acknowledge that waste bank has positive impacts in social, economic, and environmental aspect, while the impact of pandemic on waste bank operation brings social, economic, and ecological implications. The economic value of waste collected at waste bank has declined by 84%, while the RAPFISH-MDS analysis reveals that waste bank is less sustainable. Development and financial support from external parties may help the waste bank’s sustainability.
Keyword: development, economic value, perception, sustainability

Judul: Socio-Economic and Environmental Benefits and Participation of Waste Bank Customers during the COVID-19 Pandemic. (Case Study: Rangga Mekar Garbage Bank, South Bogor District, Bogor City)
Abstrak: Penetapan kebijakan PSBB di Kota Bogor telah menyebabkan aktivitas masyarakat lebih banyak dilakukan dari rumah. Dampaknya, timbulan sampah yang berasal dari aktivitas rumah tangga mengalami peningkatan. Oleh karena itu diperlukan peran pengelolaan sampah rumah tangga seperti bank sampah. Salah satu bank sampah yang tetap aktif saat Pandemi COVID-19 adalah Bank Sampah Rangga Mekar. Penelitan ini bertujuan untuk (1) menganalisis tingkat partisipasi nasabah bank sampah terhadap pengelolaan sampah rumah tangga, (2) menganalisis manfaat sosial, ekonomi, dan lingkungan atas keberadaan bank sampah, dan (3) menganalisis faktor yang memengaruhi partisipasi nasabah dalam menabung sampah. Penelitian ini menggunakan metode analisis deskriptif kuantitatif dan analisis regresi Poisson. Hasil penelitian menunjukkan bahwa secara umum tingkat partisipasi nasabah lama dalam pengelolaan sampah rumah tangga tergolong sedang sedangkan nasabah baru masih rendah. Manfaat sosial yaitu penyerapan tenaga kerja, meningkatnya interaksi antar warga, peningkatan soft skill pengurus bank sampah dan pemberdayaan masyarakat melalui kegiatan urban farming. Manfaat ekonomi berupa peningkatan jumlah saldo tabungan dan share pendapatan. Manfaat lingkungan yaitu perbaikan kebersihan dan keindahan lingkungan. Faktor usia, jarak rumah ke bank sampah, jumlah anggota keluarga dan ketersediaan waktu luang mempunyai pengaruh terhadap partisipasi nasabah dalam menabung sampah selama Pandemi COVID-19., The establishment of the PSBB policy in the city of Bogor has caused more community activities to be carried out from home. As a result, the generation of waste originating from household activities has increased. Therefore, the role of household waste management is needed, such as a waste bank. One of the waste banks that remained active during the COVID-19 pandemic was the Rangga Mekar Garbage Bank. This study aims to (1) analyze the level of participation of waste bank customers in household waste management, (2) analyze the social, economic, and environmental benefits of the existence of a waste bank, and (3) analyze the factors that influence customer participation in saving waste. This research uses descriptive quantitative analysis method and Poisson regression analysis. The results showed that in general the level of participation of old customers in household waste management was moderate, while new customers were still low. Social benefits include employment, increased interaction between residents, increased soft skills of waste bank management and community empowerment through urban farming activities. Economic benefits in the form of an increase in the number of savings balances and share of income. Environmental benefits, namely improving the cleanliness and beauty of the environment. Age factors, distance from house to waste bank, number of family members and availability of free time have an influence on customer participation in saving waste during the COVID-19 pandemic.
Keyword: pengelolaan sampah, regresi Poisson, share pendapatan, urban farming

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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