Judul: Effect of Starter Concentration and Waste type on LOF Quality and Socio-Preneurship Potential
Abstrak: Meningkatnya pertumbuhan masyarakat menyebabkan bertambahnya produksi sampah rumah tangga. Akan tetapi, hanya 1,2% rumah tangga yang mengelola sampahnya. Sampah sisa sayuran serta kulit buah dapat diolah kembali menjadi pupuk organik cair (POC) dengan bantuan mikroorganisme lokal (MOL). Penelitian bertujuan untuk menentukan potensi socio-preneurship (kewirausahaan sosial) dalam produksi POC oleh warga Klaster Linggabuana serta menentukan pengaruh bahan baku dan konsentrasi starter terhadap unsur hara pupuk. POC diperoleh dengan cara dekomposisi bahan baku menggunakan alat komposter. Responden (warga Klaster Linggabuana) memiliki potensi kewirausahaan sosial untuk memproduksi POC secara mandiri. POC berbahan baku sampah sayuran dan menghasilkan pupuk dengan kandungan unsur hara lebih tinggi dibandingkan POC berbahan baku sampah kulit buah. Konsentrasi starter 5% menghasilkan kandungan unsur hara lebih tinggi dibandingkan dengan konsentrasi starter 10%. Kombinasi POC terbaik adalah POC berbahan dasar sayuran dengan konsentrasi starter 5% dengan kandungan unsur N tertinggi., The increase of population growth has causing high production of household waste. However, only 1.2% of households manage their waste. Vegetable waste and fruit peels can be reprocessed into liquid organic fertilizer (LOF) with the help of local microorganisms. The research aims to determine the potential of socio-preneurship in LOF production by the residents of Linggabuana Klaster and the effect of raw materials and starter concentrations on fertilizer nutrients. LOF is obtained by decomposing raw materials using a composter. Respondents (residents of the Linggabuana Klaster) have the potential for social entrepreneurship to produce LOF independently. Nutrient content of LOF made from vegetable waste is higher than LOF made from fruit peel waste. The starter concentration of 5% resulted in a higher nutrient content than the starter concentration of 10%. The best combination of LOF is made from vegetables waste with a 5% of starter concentration which contain the highest of nitrogen.
Keyword: household waste, liquid organic fertilizers, local microorganisms, nutrients, socio-preneurship

Judul: The Production and Application of Liquid Organic Fertilizer (LOF) as Nutrient Substitution of AB Mix on the Water Spinach (Ipomoea reptans) Growth in the Hydroponic Wick System
Abstrak: Nutrisi AB mix yang beredar di pasaran memiliki harga yang relatif tinggi, sehingga dibutuhkan alternatif lain yang lebih ekonomis. Salah satu alternatif yang dapat dilakukan adalah dengan menggunakan Pupuk Organik Cair (POC) buatan sendiri. Penelitian ini dilakukan untuk mengetahui kualitas POC berbahan dasar limbah kulit pisang dan cangkang telur ayam, mengetahui pengaruh POC terhadap pertumbuhan tanaman kangkung pada hidroponik wick system, dan mengetahui apakah POC dapat digunakan sebagai substitusi nutrisi AB mix. Tahapan penelitian meliputi tiga tahap, tahap pertama merupakan analisis unsur hara bahan baku. Tahap kedua, pembuatan POC dan analisis unsur hara. Hasil fermentasi pupuk disebut POC PT. Tahap ketiga, uji tanam pada tanaman kangkung pada hidroponik wick system. Percobaan disusun menggunakan Rancangan Acak Lengkap (RAL) dengan lima perlakuan pupuk yaitu P0 (kontrol), P1 (nutrisi AB mix), P2 (POC PT 150%), P3 (POC PT 100%), P4 (POC PT 50%) dengan tiga kali ulangan. Analisis data menggunakan sidik ragam (ANOVA) dan uji DMRT. Hasil analisis menunjukkan bahwa POC yang telah difermentasi selama tiga minggu memiliki kandungan unsur hara yang rendah dan belum memenuhi standar Kementerian Pertanian. Hasil uji tanam pada perlakuan POC PT di satu MST menghasilkan nilai pertumbuhan tanaman lebih rendah dibandingkan dengan perlakuan nutrisi AB mix sehingga perlu dilakukan penambahan pupuk Ca(NO3)2. Perlakuan POC PT memiliki nilai yang lebih tinggi dibandingkan dengan perlakuan kontrol pada seluruh parameter pertumbuhan tanaman kangkung. POC PT sebagai substitusi nutrisi AB mix belum mampu memberikan pertumbuhan optimal pada pertumbuhan kangkung di hidroponik wick system, The price of AB mix is relatively high, so it needed to find another alternative with a more economically price. One of alternative was Liquid Organic Fertilizer (LOF). This study was aimed to know the quality of LOF made from banana peel and chicken egg shells, the effect of LOF on the water spinach grown in the hydroponic wick system, and whether LOF can be used as a substitute for AB mix. The experiment consisted of three stages. First stage was nutrients analysis of raw materials. Second stage was the production of LOF and nutrients analysis. The results of fermented fertilizers called POC PT. Third stage was experiment on water spinach in a hydroponic wick system. The experiment used Completely Randomized Design (CRD) with five fertilizer treatments, namely P0 (control), P1 (AB mix nutrition), P2 (LOF PT 150%), P3 (LOF PT 100%), P4 (LOF PT 50%) in three replications. Data was analyzed using analysis of variance (ANOVA) and DMRT test. The experiment showed that LOF which was fermented for 3 weeks have a low nutrient content and below the standard of Ministry of Agriculture. The results showed that LOF PT in one week after planting have lower plant growth compare to the AB mix nutrient so it was necessary to add Ca(NO3)2 fertilizer. The LOF PT treatment have higher plant growth parameter than the control treatment. Thus, the treatment of LOF PT could not subtitue AB mix.
Keyword: pupuk organik cair, limbah cangkang telur, limbah kulit pisang, fermentation, chicken egg shells, banana peel waste

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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