Judul: Utilization of Solid Waste from Broiler Cultivation at PT Sumber Agro Semesta Tanjungsari Bogor Regency
Abstrak: Limbah padat hasil budi daya ayam pedaging di PT Sumber Agro Semesta dijual langsung ke pembeli dengan harga yang relatif murah. Pengomposan menjadi salah satu alternatif pemanfaatan limbah padat yang dapat meningkatkan nilai tambah produk. Tujuan proyek ini adalah mengidentifikasi sumber terbentuknya limbah dan banyaknya limbah yang dihasilkan pada proses budi daya ayam pedaging, menganalisis formulasi pengomposan dan kualitas kompos dari limbah budi daya ayam pedaging, serta memberikan gambaran analisis biaya pengomposan skala laboratorium. Banyaknya limbah padat yang dihasilkan yaitu 56.000 kg dengan komposisi 64% sekam padi dan 36% kotoran ayam. Pengomposan yang dilakukan menggunakan metode dekomposisi aerob dengan formula 3 kg limbah padat dan 2 kg kotoran kambing. Parameter yang diamati selama proses pengomposan yaitu kadar air, suhu, dan rasio C/N. Rasio C/N awal yang ditetapkan sebesar 35, produk akhir kompos memiliki rasio C/N 17,25, kadar air akhir 42,05%, dan suhu akhir yaitu 28,33oC. Produk kompos selanjutnya dianalisis mutunya berdasarkan standar mutu SNI 19-7030-2004. Analisis biaya skala laboratorium yang digunakan yaitu perhitungan Harga Pokok Produksi (HPP) adalah Rp. 1.580,-/kg., Solid waste from broiler cultivation at PT Sumber Agro Semesta is sold directly to buyers at relatively low prices. Composting is an alternative to solid waste that can increase the added value of the product. The purpose of this project is to identify the sources of waste and waste generated in the broiler farming process, to analyze the composting formulation and organic quality of broiler farm waste, as well as to describe the cost analysis of laboratory-scale composting. The amount of solid waste produced is 56.000 kg with a composition of 64% rice husks and 36% chicken manure. Composting was carried out using the aerobic decomposition method with the formula 3 kg of solid waste and 2 kg of goat manure. Parameters observed during the composting process were air content, temperature, and C/N value. The initial C/N value was set at 35, the final compost product had a C/N value of 17,25, the final moisture content was 42,05%, and the final temperature was 28,33oC. The compost product is then analyzed based on the quality standard of SNI 19-7030-2004. Laboratory-scale analysis used is the calculation of the Cost of Production is Rp. 1.580,-/kg.
Keyword: C/N Value, Composting, Solid Waste, Temperature, Water Content

Judul: Desain Teknik Proses Co-composting Sludge, Abu Ketel dan Dregs PT Tanjungenim Lestari Pulp and Paper dengan Metode Windrow Composting
Abstrak: PT Tanjungenim Lestari Pulp and Paper menghasilkan limbah padat dalam jumlah besar diantaranya sludge 30 ton/hari, abu ketel 33,7 ton/hari dan dregs 3 ton/hari. Limbah ditangani dengan ditimbun langsung di sanitary landfill, diperlukan pemanfaatan lain agar bisa meminimalisir dampak limbah terhadap lingkungan dan menciptakan produk bernilai tambah. Limbah mengandung bahan organik yang dapat digunakan sebagai bahan baku co-composting. Co-composting merupakan metode pamanfaatan limbah dengan mencampurkan dua bahan atau lebih dengan bantuan mikroorganisme untuk mendekomposisi bahan. Penelitian dilakukan untuk mengetahui karakteristik limbah padat, merancang desain proses co-composting sludge, abu ketel dan dregs serta menganalisis mutu produk kompos sesuai dengan SNI-7847-2012. Co-composting dilakukan dengan menggunakan komposter berdimensi (100×80×70) cm untuk panjang, lebar dan tingginya. Berdasarkan nilai rasio C/N bahan didapatkan formulasi komposisi bahan untuk pengomposan adalah 2:1:1 dengan nilai rasio C/N awal yang ditetapkan 30. Co-composting dilakukan selama 32 hari dengan pemberian aerasi setiap 3 hari sekali. Produk kompos yang dihasilkan memiliki nilai rasio C/N sebesar 19,58. Nilai pH yang dihasilkan pada produk kompos adalah sebesar 5,75 dengan kadar air akhir 41,88%. Rendemen yang dihasilkan sebesar 75,1% dengan penyusutan 24,9%. Kompos yang dihasilkan memiliki warna kehitaman khas dregs dengan bau khas dregs pula. Kompos tidak mengandung bakteri pathogen Coliform fecal dan Salmonella sp., PT Tanjungenim Lestari Pulp and Paper produces a large amount of solid waste including sludge 30 tons/day, boiler ash 33.7 tons/day and dregs 3 tons/day. Waste is handled by being dumped directly in sanitary landfills, other utilization is needed in order to minimize the impact of waste on the environment and create value-added products. Waste contains organic matter that can be used as raw material for co-composting. Co-composting is a method of utilizing waste by mixing two or more materials using the help of microorganisms to decompose the material. The research was conducted to determine the characteristics of solid waste produced, design the process of co-composting sludge, boiler ash and dregs and analyze the quality of compost products in accordance with SNI-7847-2012. Co-composting was carried out using a composter with dimensions of 100 cm for length, 80 cm for width and 70 cm for height. Based on the C/N ratio value of the material, the material composition formulation for composting was 2:1:1 with the initial C/N ratio value set at 30. Co-composting was carried out for 32 days with aeration every 3 days. The resulting compost product has a C/N ratio value of 19.58. The pH value produced in the compost product was 5.75 with a final moisture content of 41.88%. The resulting yield was 75.1% with 24.9% shrinkage. The compost produced has a blackish color typical of dregs with a distinctive smell of dregs as well. The compost does not contain pathogenic bacteria Coliform fecal and Salmonella sp.
Keyword: abu ketel, co-composting, dregs, sludge, windrow

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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