Judul: Design and Performance Test of Biofilter to Reduce Environmental Odor Disorders
Abstrak: Increasing the number of broiler production in Indonesia from 2021 to 2022 increased by 18% from 3,185,698.4 tons to 3,765,573.09 tons, so closed houses are required for broiler cultivation. However, closed house is not equipped with exhaust air treatment from blower. Processing technology that can be used, namely biofilter. Therefore, this study aims design biofilters to reduce odors, test the performance of biofilters, and analyze environmental odor disturbances. This research is conducted in Waste Management School (SPenSa), Bogor City, from October 2022-April 2023. Odor measurements are carried out by measuring the ammonia and hydrogen sulfide parameters’s odor gas concentration and hedonism scale by panel method. The filter media use light brick with the number of bacteria contained, Bacillus sp. of 3.6x106 CFU/g. Reactor temperature and humidity of 25-35OC and 95-100%. The built biofilter has been able to reduce odors. The bigger odor’s source and the more cultivated broilers, the bigger the biofilter reactor will be. ammonia parameter’s odor reduction efficiency is 50-80%. Panel method’s odor reduction efficiency is 95.5-100.0%. The correlation between the ammonia’s concentration and hedonism scale has coefficient of determination (R2) of 0.6712. The higher the odor gas concentration, the lower the hedonism scale given by the panelists., Peningkatan jumlah produksi ayam pedaging di Indonesia dari tahun 2021 ke 2022, meningkat sebesar 18% dari 3.185.698,4 ton menjadi 3.765.573,09 ton, sehingga semakin banyak closed house yang dibutuhkan unuk tempat budidaya ayam pedaging. Namun, closed house tidak dilengkapi pengolahan buangan udara dari blower. Teknologi pengolahan yang dapat digunakan, yaitu biofilter. Oleh karena itu, penelitian ini bertujuan rancang bangun biofilter untuk mereduksi kebauan, menguji kinerja biofilter, dan menganalisis gangguan kebauan lingkungan. Penelitian ini dilakukan di Sekolah Pengelolaan Sampah (SPenSa), Kota Bogor pada Oktober 2022-April 2023. Pengukuran bau dilakukan dengan pengukuran konsentrasi gas kebauan parameter amonia dan hidrogen sulfida serta skala hedonisme dengan metode panel. Media filter yang digunakan, yaitu bata ringan dengan jumlah bakteri yang terkandung, yaitu Bacillus sp. sebesar 3,6x106 CFU/g. Temperatur dan kelembaban reaktor sebesar 25-35oC dan 95-100%. Biofilter yang dibangun telah mampu mereduksi bau. Semakin besar tempat sumber bau dan semakin banyak ayam pedaging yang dibudidaya, semakin besar juga reaktor biofilter. Efisiensi reduksi kebauan pada parameter amonia sebesar 50-80%. Efisiensi reduksi kebauan dengan metode panel sebesar 95,5-100,0%. Korelasi antara konsentrasi gas amonia dan skala hedonisme memiliki koefisien determinasi (R2) sebesar 0,6712. Semakin tinggi konsentrasi gas kebauan, semakin rendah skala hedonisme yang diberikan oleh panelis.
Keyword: odor, biofilter, hedonism scale, odor gas concentration, reduction efficiency

Judul: Analysis of Odour Levels in Ambient Air to Determine Environmental Nuisance Scale
Abstrak: Sebagian masyarakat merasakan kehadiran bau yang mengganggu meskipun konsentrasi baunya tidak melanggar Kepmen LH No. 50 Tahun 1996. Penelitian ini bertujuan menganalisis konsentrasi senyawa kebauan dalam udara ambien, menentukan skala kebauan berdasarkan konsentrasinya dalam udara ambien, dan merancang bangun alat reduksi konsentrasi gas kebauan. Pengujian dilakukan dengan pengukuran konsentrasi gas kebauan dan skala hedonisme panelis menggunakan kuesioner. Hasil analisis menunjukkan bahwa konsentrasi lima (5) parameter gas, yaitu amonia, metil merkaptan, hidrogen sulfida, metil sulfida, dan stirena di Lingkungan Industri Kecil (LIK) Kabupaten Magetan dan bak kompos Kota Bogor berada di bawah baku mutu. Semakin dekat titik lokasi pengukuran dengan sumber bau, kesan bau yang dirasakan semakin kuat. Hubungan antara konsentrasi gas dan skala hedonisme pada parameter amonia, yaitu sangat kecil, seperti terlihat dari koefisien koefisien determinasi (R2) sebesar 0,2189 di LIK Magetan dan 0,0476 di sekitar bak kompos. Nilai rata-rata skala hedonisme bau tinja dan bangkai masing-masing sebesar -3,0 dan -3,2. Nilai skala hedonisme bau tersebut dapat direduksi menggunakan biofilter. Efisiensi reduksi biofilter untuk reduksi bau ikan busuk sebesar 35%, bau kotoran kambing sebesar 70%, bau limbah kompos sebesar 82%, dan bau bangkai ayam sebesar 47%., Some people feel disturbing odour although the smell concentration does not violate the Minister of Environment Decree No. 50 of 1996. This study aims to measure and analyze the odorous compound’s concentration and several types of odour sources in ambient air, determine an odor scale based on its concentration in ambient air, and design odour gas concentration reduction device. The test carried out by measuring odorous gases’s concentration and hedonism scale questionnaire by panelists. The results concentration of five gas parameters, namely ammonia, methyl mercaptan, hydrogen sulfide, methyl sulfide, and styrene in the small industrial environment (LIK) of Magetan Regency and compost bins in Bogor City is below the quality standard. The odour smell stronger when measurement is closer to the source. The relationship between gas concentration and hedonism scale on ammonia parameter is very least as seen from coefficient of determination (R2) of 0.2189 (LIK Magetan) and 0.0476 (compost bin). The hedonism scale’s average of feces and carcasses odour was -3,0 and -3.2. The odor hedonism scale can be reduced using a biofilter. Biofilter’s reduction efficiency on rotten fish odour is 35%, goat manure odour is 70%, compost waste is odour 82%, and chicken carcass odour is 47%.
Keyword: : biofilter, hedonic scale, odour gas concentration, panelists

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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