Judul: Identifikasi dan Pencirian Fisikokimia Gelatin dari Tulang Sapi dan Babi
Abstrak: Gelatine is a derivative product of protein isolated from collagen tissue of animal skins and bones. In this study, gelatines were isolated from bovine and porcine bones, identified and characterized for their physicochemical properties including proximate, viscosity, pH, and mineral contents, as well as functional group and characteristic amino acids composition analysis. Bovine and porcine gelatine isolates were not obtained in crystal form as their standard forms, which affected viscosity and gelling abilities of the gelatines. Low yield of gelatine isolates were due to the high remaining phosphorus content, causing incomplete collagen extraction. Functional group analysis showed the existence of amide A (3438 cm-1), amide I (1651 cm-1), and amide II (1454 cm-1) characterizing the functional groups bovine gelatine isolate. However, the existence of amide III (1245 cm-1) still showed the structure of unhydrolized tropocollagen. Analysis of characteristic amino acids composition showed higher glysine amount in bovine gelatine than that in porcine.
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Judul: Perbandingan Ekstraksi Gelatin Kulit Sapi Split dengan Proses Asam dan Basa
Abstrak: Gelatin is a protein derivative from collagen fiber contained in the skin tissue, bone, and cartilage. Bovine hide is potential to be used in gelatin industry because it contains high collagen fiber, i.e. 89%. The hide can be obtained from the slaughterhouse or tannery industry. Split leather from tannery industry has not been utilized optimally. Gelatin production process can be classified mainly into two processes, i.e. acid or base process. Acid process produced gelatin type A while base process produced gelatin type B. These processes are different based on solution type and soaking period. Acid process is performed by soaking the leather in HCl 1%for 24 hours, while base process is carried out by soaking the leather in Ca(OH)2 3% and NaOH 0.05% for 7 days. Parameters observed in this study were moisture content, ash, protein, fat, color, acidity (pH), gel strength, viscosity, and molecular weight. The yield of gelatin from tannery and slaughterhouse leather obtained in this study were 22.12% and 30.77% for gelatin type A, respectively, and 6.40% and 26.12% for gelatin type B, respectively. The characteristics of the gelatin, from tanning manufacture and slaughterhouse, had complied SNI (1995) and BSI (1975). Thus, tannery leather is a potential source for gelatin. The yield showed that the acid process was better than the base process, while based on properties such as the viscosity, molecular weight, and gel strength, the base process was better than the acid process.
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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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