Judul: Studi Inhibitor Alfa-Amylase Pada Pohon Sengon (Paraserianthes falcataria (L) Nielsen) Provenan Kediri, Solomon dan Subang
Abstrak: Sengon (Paraserianthes falcataria (L) Nielsen) merupakan salah satu jenis pohon yang cukup potensial untuk dikembangkan karena manfaatnya yang sangat beragam. Namun saat ini penanaman jenis sengon tengah dihadapkan pada masalah serangan hama penggerek batang (Xystrocera festiva Pascoe) atau dikenal sebagai boktor. Dalam pencernaan boktor terdapat enzim α-amylase dan di dalam pohon sengon terdapat senyawa yang bersifat inhibitor terhadap enzim α-amylase tersebut. Untuk itu diperlukan suatu studi mengenai inhibitor α-amylase. Informasi yang diperoleh akan digunakan untuk menghasilkan bibit sengon yang unggul, yaitu memiliki kandungan aktivitas inhibitor α-amylase tertinggi sehingga dapat menghambat kerja enzim α-amylase dari pencernaan boktor. Penelitian ini bertujuan untuk mengamati perbedaan aktivitas inhibitor α-amylase pohon sengon provenan Kediri, Solomon dan Subang, baik di bagian batang maupun kulit pada pohon sehat dan sakit. Selain itu juga membandingkan aktivitas inhibitor α-amylase menggunakan enzim sintetis dan enzim alami dari pencernaan larva boktor. Obyek penelitian adalah batang dan kulit pohon sengon provenan Kediri, Solomon, dan Subang yang dibuat menjadi serbuk. Pohon yang digunakan adalah pohon dengan kondisi sehat dan terserang hama boktor. Pengamatan aktivitas inhibitor α-amylase dilakukan menggunakan enzim sintetis α-amylase (SIGMA, 320 U/mg) dan enzim alami dari pencernaan larva boktor berukuran 3,5 cm. Data diolah dengan Rancangan Acak Lengkap Faktorial dengan tiga faktor, yaitu provenan, kondisi pohon dan bagian pohon menggunakan SPSS 18.0.
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Judul: Studi Trypsin Inhibitor dan Alfa-amylase Inhibitor pada Pohon Sengon (Paraserianthes falcataria (L) Nielsen) Provenan Banjarnegara dan Subang
Abstrak: Plantation of sengon (Paraserianthes falcataria (L) Nielsen) almost always faces the problem of attack by stem borer pest insect, referred to as boktor (Xystrocera festiva Pascoe). The damage and loss incurred by this pest is considerable. In the effort of preventing this attack by boktor there is a need for planting sengon which are resistant to attack by this pest through tree improvement program. Therefore, there is a need for research on the presence of anti pest substance in the form of trypsin inhibitor and α-amylase inhibitor in each part of the tree. Object of this research was part of sengon trees of Banjarnegara and Subang provenances in the form of leaves, bark, and wood, which were made into powder. The trees used in this study were healthy trees and trees attacked by the pest boktor, with replication of five trees for each category of tree condition. Observation of trypsin inhibitor activity was conducted using synthetic substrate benzoil-DL-arginin-p-nitroanilid (BAPNA), enzyme trypsin (SIGMA 3,5 U/mg) and natural enzyme from digestive system of boktor larvae with size of 1,5 cm. Observation of α-amylase inhibitor activity used materials of solution of soluble starch, solution of enzyme α-amylase (SIGMA 320 U/mg), and enzyme α-amylase which was extracted from larvae with size of 3,5 cm. Data were processed in Completely Randomized Design (RAL) with 3 factors, namely provenances, tree condition and parts of tree, using software SPSS 12.0 Survey results showed that larvae in bark had length and weight less than larvae in wood. Of the 5 trees of Banjarnegara provenance, boktor larvae were found only in the wood part, whereas in that of Subang provenance, boktor larvae were found in wood and bark parts. Based on analysis of variance, factor of provenance did not have significant effect on activity of trypsin inhibitor. Tree parts and tree condition had very significant effect on activity of trypsin inhibitor. Interaction between factors of provenance and tree parts gave significant effect on activity of trypsin inhibitor. Duncan advanced test showed that bark possessed highest activity of trypsin inhibitor, whereas that of the wood was the lowest. Results of analysis of variance showed that tree condition (healthy or sick trees), as well as tree parts in the form of leaves, bark and wood, had significant effect on activity of α-amylase inhibitor (AIA). On the other hand, provenance factor did not have significant effect. Duncan advanced test showed that wood was the part which had the highest average of α-amylase inhibitor activity, whereas that of the lowest, was in bark part. Interaction between tree condition and tree parts had very significant effect on the magnitude of α-amylase inhibitor activity. Analysis of variance showed that average values of trypsin inhibitor activity which were obtained using synthetic enzyme and natural enzyme from digestive system of boktor did not show significant differences. The same phenomenon was also found for provenance factor. Activity of trypsin inhibitor which was tested using synthetic enzyme was greater compared with that of natural enzyme from boktor digestive system. On the other hand, tree condition had significant effect, where the healthy
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Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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