Judul: Skrining Bakteri Dekomposer Sebagai Penghilang Bau Kotoran Ayam
Abstrak: Proses dekomposisi ekskreta ayam menghasilkan gas-gas berbau penyebab polusi lingkungan. Salah satu teknik alternatif untuk mengurangi bau adalah dengan penggunaan bakteri spesifik. Tujuan dari penelitian ini adalah untuk mendapatkan isolat bakteri yang mampu mengurangi bau. Bakteri yang digunakan diisolasi dari kotoran ayam, guano, dan tanah gambut. Pemilihan isolat bakteri dilakukan dengan menggunakan media selektif. Semua isolat yang diperoleh diuji reaksi hipersensitif (HR) pada tembakau dan hemolisis (HL) pada agar darah. Bakteri yang menunjukkan respon HR dan HL negatif kemudian digunakan untuk percobaan lebih lanjut. Isolat tersebut diuji pada 100g ekskreta ayam. Lima isolat bakteri terpilih berdasarkan kemampuan mengurangi bau pada uji organoleptik adalah WiK 15, TnK 7, WiGu 11, CGu 7 dan MaGa 5. Gas NH3 dan H2S merupakan gas berbau yang diuji pada tahap selanjutnya. NH3 dan H2S dari dekomposisi ayam ekskreta dianalisis dengan metode spektrofotometri dan kolorimetri. Rata-rata produksi kumulatif NH3 dari tujuh hari pengamatan berkisar antara 1,09 ppm sampai 1,77 ppm, sedangkan total produksi kumulatif gas H2S berkisar antara 15,05 sampai 16,57 ppm. Isolat bakteri CGU 7 menunjukkan produksi NH3 terendah.
Keyword: chicken excreta, odorous gases, oxidizing bacteria

Judul: Biogas from a Mixture of Banana Stalks and Chicken  Manure
Abstrak: Usaha peternakan ayam ras petelur menghasilkan kotoran yang dapat mencemari lingkungan jika tidak ditangani dengan baik. Pengolahan kotoran ayam ras petelur perlu dilakukan untuk mengurangi dampak negatif bagi lingkungan. Biogas merupakan teknologi yang dapat menghasilkan sumber bahan bakar alternatif yang dapat diperbaharui karena menggunakan bahan baku yang berasal dari kotoran ternak. Tujuan penelitian ialah menganalisis potensi biogas dari campuran kotoran ayam ras petelur dan batang pisang. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) 3 perlakuan yaitu kontrol (K100B0: 100% kotoran ayam), perlakuan 1 (K70B30: kotoran ayam 70% dan batang pisang 30%) dan perlakuan 2 (K50B50: kotoran ayam 50% dan batang pisang 50%) yang disimpan dalam digester yang berukuran 30 liter selama 35 hari. Parameter yang diamati pada penelitian ini adalah pH, total solid (TS), volatile solid (VS), uji nyala api dan volume gas. Produksi biogas yang diindikasikan oleh TS dan VS awal dan akhir pada perlakuan 1 dan 3 lebih tinggi (P>0,05) daripada kontrol. Nyala api pada perlakuan 1 dan perlakuan 2 lebih lama dan api yang dihasilkan berwarna biru dengan kandungan metana lebih tinggi daripada yang kontrol. Hasil penelitian ini mengindikasikan potensi yang tinggi pemanfaatan kotoran ayam ras petelur dan batang pisang sebagai bahan pembuatan biogas., Layer chicken production produces manure that could be pollute the environment if those are not handled properly. Waste treatment, therefore, need to be done to minimize the negative impact of manure pollution to the environment. Biogas is an alternative technologies to produce a renewable energy by using raw materials derived from livestock manure. This research objective is to analyze the the potency of layer chicken manure and banana stalks as raw material for biogas production. The study used completely randomized design. There were 3 treatments in this study, namely control (K100B0: 100% layer chicken manure), treatment 1 (K70B30: 70% chicken manure and 30% banana stalks), and treatment 2 (K50B50: 50% chicken manure and 50% banana stalks) using a digester with a volume of 30 liter, and incubated for 35 days. Parameter measured in this study were pH, total solid (TS), volatile solid (VS), flame, and gas volume. The treatment groups (K70B30 and K50B50) produced higher (P>0.05) biogas production compared to control group that was indicated by higher initial and final TS and VS content. The methane content and flame produced by treatment groups (K70B30 and K50B50) were longer than the control (K100B0). Those above results show the high potency of layer chicken manure and banan stalks as materials for biogas
Keyword: banana stalks, biogas, layer chicken manure, pH, total solid, volatile solid, flame, gas volume

Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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