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 Mustard Green Growth (Brassica juncea L.) in the Hydroponic Wick System
Abstrak: Limbah kulit nanas dan cangkang telur ayam dapat dimanfaatkan sebagai pupuk organik cair (POC). Penelitian ini bertujuan mengetahui kualitas POC berbahan dasar limbah kulit nanas dan cangkang telur ayam, mengetahui pengaruh POC terhadap pertumbuhan tanaman caisim pada hidroponik wick system, dan mengetahui apakah POC dapat digunakan sebagai substitusi nutrisi AB Mix. Lokasi penelitian dilakukan di Laboratorium Kimia dan Kesuburan Tanah dan Kebun Percobaan DITSL, IPB. Hasil fermentasi limbah kulit nanas dan cangkang telur ayam disebut POC NC. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) dengan lima taraf perlakuan dan tiga kali ulangan di setiap tarafnya. Taraf perlakuan di antaranya P0 (Kontrol), P1 (Nutrisi AB Mix), P2 (POC NC 150%), P3 (POC NC 100%), P4 (POC NC 50) dengan tiga kali ulangan. Analisis data menggunakan sidik ragam (ANOVA) dan uji DMRT. Pembuatan POC melalui tahap fermentasi selama 21 hari. Hasil analisis menunjukkan kadar hara POC belum memenuhi standar Kementerian Pertanian. Pemberian POC berpengaruh terhadap pertumbuhan tanaman caisim. Tanaman caisim dengan perlakuan POC NC pada dua MST menghasilkan pertumbuhan yang jauh lebih rendah dibanding perlakuan AB Mix, sehingga dibutuhkan penambahan Ca(NO3)2 sebanyak 400 ppm untuk meningkatkan kadar hara nitrogen yang dapat diserap oleh tanaman. Seluruh parameter pengamatan menunjukkan perlakuan dengan taraf terendah yaitu 50% menghasilkan pertumbuhan yang baik dibanding perlakuan kontrol. Pemberian POC pada pertumbuhan tanaman caisim belum mampu menjadi substitusi nutrisi AB Mix pada sistem hidroponik., The wastes of pineapple fruit peel and chicken egg shells could be processed into liquid organic fertilizer (LOF). This study was aimed to know the quality of LOF made from the wastes of pineapple fruit peel and chicken egg shells, the effect of LOF on the mustard green grown in the hydroponic wick system, and whether LOF can be used as a substitute for AB Mix. The research location was carried out at the Chemistry and Soil Fertility Laboratory and Cikabayan Experimental Station, IPB University. The fermented of pineapple peel waste and chicken egg shells waste was called LOF NC. This experiment used a completely randomized design (CRD) with five levels of treatments. The treatments consisted of P0 (Control), P1 (AB Mix Nutrition), P2 (LOF NC 150%), P3 (LOF NC 100%), P4 (LOF NC 50%) on three replications. Data well analyzed using analysis of variance (ANOVA) and DMRT test. The fermentation of LOF NC was 21 days. The results showed that LOF nutrient levels did not meet the standard of the ministry of agriculture. The treatment of LOF affected the growth of mustard green. All observation parameters showed that the treatment of 50% level LOF produced highest yield as compared with control. This treatment of LOF could not substitute the AB Mix in the hydroponic system.
Keyword: Chicken Egg Shells Waste, Pineapple Peel Waste, Nutrient Content

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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