Judul: Identifikasi komponen kimia empat tingkat mutu gaharu
Abstrak: Agarwoods (Aquilaria malaccensis) with 4 different commercial grades has been identified, namely kacangan B, teri B, medang A, and medang B, from the highest to the lowest grade. In this work, resin content tends to increase as the grade increases. However, the resin content does not have correlation with the content of sesquiterpene and chromone which determine the grade of agarwoods. In isolation step, the agarwood samples were fractionated using gradient column chromatography method with hexaneethyl acetate as eluent and were grouped according to its Rf point. Identification of samples using gas chromatography-mass spectrophotometer showed the presence of 10 sesquiterpenes and 3 chromones in various levels.
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Judul: Korelasi Kadar Seskuiterpena dengan Mutu Gaharu Standar Nasional Indonesia
Abstrak: Sesquiterpene content of agarwoods (Aquilaria malaccensis) of 3 different commercial grades, namely kemedangan, super tanggung A and, super A, representing low to high grades, has been identified. However, parameters designated in Indonesia National Standard (SNI) are merely qualitative, based on some physical properties of this commodity. The purpose of this study was to obtain quantitative chemical parameters in order to complement the existing parameters of SNI. In the identification step, agarwood samples were extracted using 2 different solvents, i.e. ethyl acetate and acetone. Gas chromatography-mass spectrophotometer analyses indicated that sesquiterpenes were present in all agarwood grades. Resin contents in acetone extract for kemedangan, super tanggung A, and super A were 8.5%, 13.3%, and 19.9%, respectively. Sesquiterpene content of acetone extract for kemedangan, super tanggung A, and super A were 6.1%, 7.1%, and 11.9%, respectively, and for ethyl acetate extract were 5.4%, 9.6%, and 13.4%. Resin and sesquiterpene content in acetone extracts consistently increased corresponding to the quality of commercial gaharu. A marker compound obtained in all the quality of agarwoods and agarwood extract was aromadendrene. Aromadendrene content in acetone extract from the lowest to the highest grades of commercial agarwoods were 1.2%, 1.6%, and 2.2%, respectively.
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Judul: Pengaruh vaksinasi terhadap dinamika populasi pada model SIR (Susceptible-Infected-Recovered)
Abstrak: SIR model can be used to model the spread of diseases in a closed population based on certain assumptions. In this research, the SIR model is formulated by including the factor of vaccination. As the result, the model has been shown to have two equilibrium points, i.e. disease free and endemic equilibrium. A simulation study is carried out to illustrate the model. The results show that some equilibrium points are asymptotically stable. Moreover, a minimum level of vaccination has been defined. For the vaccination level less than the minimum level, increase in the vaccination level results in decrease of the proportion of infected individuals in the corresponding equilibrium point. On the other hand, for the vaccination level greater than the minimum level, increase in the vaccination level results in decrease the proportion of susceptible individuals in the corresponding equilibrium point. Furthermore, when vaccination level is greater than the minimum level, it is found that the time needed for the disease to extinct is shorter.
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