Judul: Pengaruh Waktu Tebang terhadap Keawetan Alami Bambu Andong (Gigantochloa psedoarundinace)
Abstrak: Gigantochloa pseduarundinaceae, also known as Andong bamboo, used in this study. Samples were taken from bamboos which were harvested once each month in a year starting from February 2013 to January 2014. Bamboos culms were cut into strips. The strips were put in a safe, dry place, and free from wood destroying organisms. After all of the bamboos were collected, the laboratory testing is conducted based on SNI 01.7207-2006 methods. Field testing were also conducted based on ASTM D 1758-06 methods. According to the laboratory test, the bamboos were categorized as durability class III (medium durability) and durability class IV (bad durability). According to laboratory testing, the least loss of bamboo mass occurred on Maret and the highest number of termite mortality occurred on November. While, the results of the field test show that the value of the highest durability grade and the weight lowest loss rate was occurred on bamboo which is harvested in March to May. Best subset regression were used to determine the environmental factors during harvesting process which was dominantly affecting the bamboos' durability. The observed environmental factors were rain levels, humidity, and temperature. According to best subset regression analysis, the rain level and humidity during the harvesting period were two main factors affecting the bamboos' natural durability. The best subset regression resulted that rainfall and humidity during the harvest were the two main factors that affect the durability of bamboo at observed daily rainfall intervals (1-20 mm). Rain levels and humidity give fluctuating effects on the loss of mass. The maximum loss was happened on 74% humidity. If the humidity is bellow 74%, or above 74%, the mass loss tend to decrease. The rain level also affect the mass loss. Low rainfall level 1 to 4 mm showed the decrease in mass loss, and became stabilized when the rain level reach above 4 mm. According to the data, it is recommended to harvest the bamboos on March to Mei, when the durability are the highest and the mass loss are the lowest.
Keyword: Bogor Agricultural University (IPB), resistance class, natural durabiliy, mass loss, harvesting time, environmental factors

Judul: Pengaruh Penundaan Perendaman Setelah Penebangan Terhadap Penurunan Kandungan Pati Bambu Andong (Gigantochloa verticillata Munro),
Abstrak: Bambu merupakan salah satu hasil hutan non kayu yang tidak asing lagi bagi masyarakat Indonesia terutama di daerah pedesaan dan telah menjadi bagian penting dalam kehidupan sehari-hari karena dapat digunakan untuk berbagai keperluan, sehingga bambu sering disebut sebagai tanaman serbaguna. Barnbu memiliki kemungkinan penggunaan yang luas untuk berbagai macam tujuan. terutama sebagai bahan bangunan. Salah satu masalah dalarn pemanfaatan bambu terutama jika digunakan sebagai komponen bangunan atau rumah adaiah mudah diserang organisme perusak kayu seperti bubuk kayu kering, rayap dan jamur yang mengakibatkan umur pakainya relatif singkat. Hal ini disebabkan oleh adanya kandungan pati di dalam bambu yang disukai faktor perusak biologis sebagai makanannya. Mengingat bambu memiliki kelemahan tersebut, diperlukan usaha peningkatan ketahanan bambu terhadap serangan organisme perusak, yakni mengadakan pengawetan terhadap bambu. Salah satu cara pengawetan bambu yang sering digunakan dan menjadi kebiasaan masyarakat adalah merendam bambu di dalam air mengalir, air tergenang atau bahkan dalam lumpur selama jangka waktu tertentu sebelum digunakan sebagai bahan bangunan. Cara pengawetan tradisional ini ternyata cukup efektif. namun membutuhkan waktu antara 1-24 minggu (Yap. 1967). Waktu pengawetan dengan cara tradisional tersebut tergolong cukup lama, sehingga perlu dilakukan upaya lain mernpercepat waktu pengawetan bambu. Salah satu fenomena yang perlu diketahui dan diadakan penelitian ke arah itu adalah bagairnana mempercepat waktu pengawetan tradisional dan mengurangi kandungan pati dengan mernanfaatkan proses rnetabolisme parenkim bambu setelah ditebang.
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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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