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: Utilization of Pumice Stone as a Bioreactor Media  to Reduce Environmental Odor Nuisance
Abstrak: Teknik biofiltrasi berfungsi untuk menghilangkan gas kebauan dengan menggunakan mikroorganisme. Pada penelitian ini, telah dilakukan biofiltrasi dengan media batu apung untuk menghilangkan bau yang berasal dari kotoran ayam dan sampah organik pasar. Penelitian bertujuan menganalisis kinerja media biofilter dan menganalisis perbedaan kinerja media biofilter untuk kedua sumber bau menggunakan metode panel dan pengukuran konsentrasi gas amonia (NH3) serta hidrogen sulfida (H2S). Pengujian biofilter dilakukan pada temperatur 25-30℃ dan kelembapan relatif 82-99% untuk sumber bau kotoran ayam dan temperatur 25-28 ℃ dan kelembapan relatif 93-99% untuk sumber bau sampah organik pasar. Efisiensi reduksi pada pengukuran konsentrasi gas dengan alat ukur konsentrasi NH3 dan H2S adalah 100%. Pada metode panel, kinerja biofilter untuk sumber bau kotoran ayam mencapai 100% untuk seluruh hari pengukuran. Namun, kinerja biofilter untuk sumber bau sampah organik pasar baru mencapai 100% pada hari ke-7. Skala hedonisme dan konsentrasi gas kebauan saling berkorelasi, yaitu semakin tinggi konsentrasi gas kebauan, maka semakin rendah nilai skala hedonisme. Hal ini ditunjukkan oleh nilai R2 sebesar 0,9., The biofiltration technique functions is to eliminate odorous gases by using microorganisms. In this research, biofiltration was carried out using pumice as a biofilter media to eliminate odor from chicken manure and organic market waste. The research aims to analyze the performance of biofilter media and analyze the differences between the biofilter performance to eliminate both odor sources using using panel method and measuring the concentration of ammonia gas (NH3) and hydrogen sulfide (H2S). Biofilter testing was carried out at a temperature of 25-30 ℃ and relative humidity of 82-99% for chicken manure odor and a temperature of 25-28 ℃ and relative humidity of 93-99% for organic market waste odor . The reduction efficiency in measuring gas concentrations method with NH3 and H2S concentration measuring instruments is 100%. In panel method, the performance of biofilter for chicken manure odor reached 100% for all measurement days. However, for market organic waste odor just reached 100% on the 7th day. The hedonism scale and odor gas concentration are correlated, the higher the odor gas concentration, the lower the hedonism scale value. This is indicated by the R2 value of 0.9.
Keyword: Biofilter, bioreactor media, environmental odor nuisance, pumice stone

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.
Keyword: