Judul: APLIKASI PRODUKSI PEMBERSIH PADA PENGEMBANGAN MINUMAN HERBAL MENIRAN
Abstrak: The application of cleaner production in the production process of meniran products is carried out to prevent or minimize waste by increasing productivity, efficiency and production effectiveness. The purpose of this study is to identify the flow of raw materials, energy and water, analyze technical, environmental and financial feasibility by calculating the payback period (PP), as well as determine the priority of implementation of cleaner production. The stages of the research consist of quick scan analysis, identification of material, energy and waste flows, determination of alternatives, feasibility analysis and selection of clean production priorities. The research was conducted by observing the production process of meniran products from meniran simplicia to ready-to- consumed products. The production process consists of maceration extraction, filtering, mixing, low temperature drying, size reduction, compounding and packaging. The recommended clean production alternatives include (1) compost making 6.09 months or 0.50 year, (2) good manufacturing practice application 6.4 months or 0.53 and (3) the replacement of mixer 1.53 months or 0.13 year. The payback period is a financial metric used to evaluate the time it takes for an investment to generate enough cash flows to recover its initial cost. given three payback periods: 6.09, 6.54, and 1.53. Among the given payback periods, the best option would be 1.53, as it represents the shortest time required to recoup the initial investment. This means that the investment would generate sufficient cash flows to cover its cost in just 1.53 month. In conclusion, based solely on the payback period metric provided, the best payback period among 6.09, 6.54, and 1.53 is 1.53 which is the replacement of Mixer as the alternative.
Keyword: Financial Analysis, Production Alternatives, Production Process

Judul: Opportunities for Application of Cleaner Production in the Tofu Industry in Dairi Regency
Abstrak: Industri tahu merupakan salah satu industri kecil yang dapat menyebabkan pencemaran lingkungan karena adanya limbah dan loss pada proses produksi sehingga dilakukan peluang penerapan produksi bersih pada industri tahu. Penelitian ini bertujuan mengidentifikasi limbah dan peluang produksi bersih, menganalisis kelayakan dan menentukan prioritas peluang produksi bersih yang dihasilkan. Tahap penelitian yang digunakan adalah tahap quick scan, identifikasi masalah, dan penentuan peluang produksi bersih, melakukan analisis kelayakan secara teknis, lingkungan dan ekonomi (B/C Ratio dan PBP), dan menentukan prioritas penerapan produksi bersih melalui Metode Perbandingan Eksponensial. Proses pembuatan tahu terdiri dari beberapa tahap yaitu perendaman, pencucian, penggilingan dan penyaringan, pemasakan, penggumpalan, penyaringan, pencetakan, pengepresan dan pemotongan. Limbah yang terbentuk diakibatkan oleh adanya ceceran kedelai dan ceceran air selama proses produksi berlangsung. Alternatif produksi bersih adalah (1) menerapkan Good Manufacturing Practice (PBP 0,2 tahun, B/C 3,6) (2) memanfaatkan whey tahu menjadi nata de soya (PBP 0,37 tahun, B/C 3,9) (3) Recycle air pencucian dan perendaman (PBP 0,49 tahun, B/C 2,49 (4) pemanfaatan limbah cair menjadi biogas (PBP 0,28 tahun, B/C 6,48). Prioritas utama sebagai penerapan peluang produksi bersih adalah penerapan GMP, karena dianggap mudah untuk diterapkan dibandingkan dengan alternative lainnya. Kata kunci: MPE, produksi bersih, periode pengembalian modal, B/C ratio, tahu, The tofu industry is one of the small industries that can cause environmental pollution due to waste and loss in the production process, so a opportunities for clean production in the tofu industry is carried out. This study aims to identify waste and clean production opportunities, analyze the feasibility and determine the priority of the resulting clean production opportunities. The research phase used is a quick scan, problem identification, and determination of clean production opportunities, conducting technical, environmental and economic feasibility analysis (B/C Ratio and PBP), and determining priorities for implementing clean production through the Exponential Comparison Method. Making tofu consists of several stages, namely soaking, washing, grinding and filtering, cooking, clumping, filtering, printing, pressing and cutting. The waste formed is caused by the spilt soybeans and water spills during the production process. Alternatives for cleaner production are (1) applying Good Manufacturing Practices (PBP 0.2 years, B/C 3.6) (2) utilizing tofu whey into nata de soya (PBP 0.37 years, B/C 3.9) ( 3) Recycle washing and soaking water (PBP 0.49 years, B/C 2.49 (4) utilization of liquid waste into biogas (PBP 0.28 years, B/C 6.48). The main priority for clean production opportunities is the use of whey into nata de soya, because it is considered easy to implement compared to other alternatives. Keywords: B/C ratio, MPE, net production, payback period, tofu.
Keyword: B/C ratio, MPE, net production, payback period, tofu, The tofu industry is one of the small industries that can cause environmental pollution due to waste and loss in the production process, so a opportunities for clean production in the tofu industry is carried out. This study aims to identify waste and clean production opportunities, analyze the feasibility and determine the priority of the resulting clean production opportunities. The research phase used is a quick scan, problem identification, and determination of clean production opportunities, conducting technical, environmental and economic feasibility analysis (B/C Ratio and PBP), and determining priorities for implementing clean production through the Exponential Comparison Method. Making tofu consists of several stages, namely soaking, washing, grinding and filtering, cooking, clumping, filtering, printing, pressing and cutting. The waste formed is caused by the spilt soybeans and water spills during the production process. Alternatives for cleaner production are (1) applying Good Manufacturing Practices (PBP 0.2 years, B/C 3.6) (2) utilizing tofu whey into nata de soya (PBP 0.37 years, B/C 3.9) ( 3) Recycle washing and soaking water (PBP 0.49 years, B/C 2.49 (4) utilization of liquid waste into biogas (PBP 0.28 years, B/C 6.48). The main priority for clean production opportunities is the use of whey into nata de soya, because it is considered easy to implement compared to other alternatives. Keywords: B/C ratio, MPE, net production, payback period, tofu.

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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