Judul: Penggunaan Ekstrak Daun Sirih untuk Mengurangi Kadar Gas NH3 pada Feses Sapi Pedaging
Abstrak: Peternakan merupakan subsektor pertanian yang mampu menyediakan sumber protein hewani bagi masyarakat, salah satunya adalah kebutuhan daging yang berasal dari sapi pedaging. Kesadaran masyarakat dalam memenuhi kebutuhan protein hewani terus meningkat sehingga populasi sapi pedaging juga meningkat dan mengakibatkan produksi limbah yang dihasilkan akan semakin banyak. Limbah tersebut menjadi salah satu penyumbang polusi udara sehingga dibutuhkan solusi untuk mengurangi pencemaran udara berupa produksi gas NH3 dari feses sapi pedaging. Ekstrak daun sirih mengandung senyawa fenol yang berpotensi sebagai antimikroba. Mekanisme kerja senyawa fenol yaitu menghambat pertumbuhan bakteri pembentuk gas NH3. Tujuan penelitian yaitu mengkaji efektivitas penggunaan esktrak daun sirih untuk mengurangi kadar gas NH3 dari feses sapi pedaging. Perlakuan yang ditambahkan yaitu kontrol, 100 mg mL-1, 150 mg mL-1, dan 200 mg mL-1. Peubah yang diamati yaitu pH, jumlah bakteri dan konsentrasi NH3. Hasil penelitian menunjukkan penambahan esktrak daun sirih tidak memberikan pengaruh pada peubah yang diamati.
Keyword: antimikroba, ekstrak, feses, NH3, sirih

Judul: Efektivitas Penggunaan Probiotik Padat dan Cair untuk Menurunkan Kadar Amonia (NH3) dan Hidrogen Sulfida (H2S) Feses Sapi Potong
Abstrak: Livestock production system could result in various environmental problems which should be reduced. Faeces of beef cattle contain several odor producing compounds (ammonia, NH3, and hydrogen sulfide, H2S) that may have negative effect on animal production. Probiotic supplementation (solid and liquid probiotic) is one alternative for reducing nitrogen excretion and other noxious gas. The aim of this study was to asses the effectivity of solid and liquid probiotic supplementation for reducing fecal NH3 and H2S concentrations in beef cattle. Eighteen local beef cattle (average initial body weight, BW, 448.8±7.16 kg) were allocated into three dietary treatments in a randomized block design (six cattles per treatments). Dietary treatments included: P1 as conrol (forage+concentrate+rice bran); P2 (P1+solid probiotic 0.25% w/w); and P3 (P1+liquid probiotic 0.1% v/w). Results showed that probiotic addition decreased significantly faecal NH3 concentration (P<0.05), but had no effect on H2S concentration. Suplementation with solid probiotic was more effective for decreasing fecal NH3 concentration than liquid probiotic supplementation.
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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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