Judul: Pengaruh Variasi Panjang dan Jumlah Batang Penyusun Kolom terhadap Kapasitas Tekuk Bambu Tali
Abstrak: Bambu adalah salah satu jenis tanaman rumput-rumputan yang termasuk ke dalam famili Poaceae. Penelitian ini bertujuan untuk menganalisis pengaruh komposisi jumlah komponen penyusun kolom dan variasi panjang kolom yang dapat mempengaruhi kekuatan tekuknya. Variasi panjang contoh uji yang digunakan dalam penelitian ini yaitu 4 meter, dan 6 meter, sedangkan ukuran 1 meter, 2 meter, dan 3 meter diambil dari penelitian sebelumnya. Pengujian tekuk bambu berukuran panjang menggunakan alat uji tekan berkapasitas 100 ton yang dirancang oleh Laboratorium Keteknikan Divisi Rekaya dan Desain Bangunan Kayu. Variasi panjang bambu dan penyusun kolom pada bambu tali sangat berpengaruh terhadap kekuatan tekuk buluh bambu. Kolom bambu tali dengan komposisi penyusun rangkap empat menghasilkan nilai kekuatan tekuk tertinggi. Semakin banyak komposisi penyusun kolom bambu akan menghasilkan kekuatan tekuk yang tinggi dibandingkan kolom tunggal maupun kolom dengan komposisi lebih sedikit., Bamboo is grass plant that belongs to the Poaceae family. This study aims to analyze the influence of a column’s component numbers and the column length variation to the column’s buckling load-bearing capacity. The specimen length variations, tested in this study, were 4 m and 6 m. Meanwhile, the buckling test results of 1 m, 2 m, and 3 m length specimens were taken from previous studies. The long-sized bamboo buckling test employes a 100-ton capacity compression machine designed by the Engineering Laboratory – Wood Building Design and Engineering. Variations length and column component of the bamboo in the Tali Bamboo column greatly affect the buckling strength of the bamboo. Tali Bamboo column with a four-culm composition showed the highest buckling capacity value. The more component numbers there is in a bamboo column, the buckling capacity will be higher compared to a single column or a column with less component numbers.
Keyword: Tali Bamboo, buckling, double column, column

Judul: Buckling Properties of Hitam Bamboo (Gigantochloa atroviolaceae) with Variations in The Number of Bamboo Culumns
Abstrak: Bambu merupakan salah satu material konstruksi yang tersebar melimpah di daerah tropis. Bambu hitam (Gigantochloa atroviolacea) memiliki buluh berwarna kehitaman dan telah banyak dibudidayakan di Indonesia. Tujuan dari penelitian ini adalah untuk mendeskripsikan bentuk geometri, sifat fisis, dan kapasitas tekan bambu, selanjutnya menganalisis pengaruh jumlah komponen penyusun multikolom bambu terhadap kapasitas tekan kolom. Contoh uji buluh bambu dipotong dengan ukuran 1 meter, 2 meter, dan 3 meter masing-masing ukuran berjumlah 30 sampel. Sampel diikat menggunakan tali ijuk berjarak 40 cm antar ikatan dengan variasi 2, 3, dan 4 komponen kolom bambu. Pengikatan kolom bambu menggunakan simpul pangkal. Pengujian tekuk menggunakan Universal Testing Machine (UTM) SATEC-Baldwin kapasitas 30 ton dan alat mesin uji tekuk kolom bambu ukuran penuh kapasitas 100 ton. Berdasarkan uji ancova jumlah komponen bambu dan kapasitas tekan dugaan berpengaruh nyata terhadap kapasitas tekan bambu. Semakin banyak jumlah komponen bambu yang menyusun sebuah kolom, kapasitas tekan kolom tersebut juga semakin besar. Sedangkan ukuran bambu secara statistik tidak berpengaruh nyata terhadap kapasitas tekan bambu karena berautokorelasi dengan kapasitas tekan dugaan. Kapasitas tekan dugaan merupakan jumlah kapasitas tekan setiap batang bambu yang menyusun sebuah kolom. Pada contoh uji dengan panjang 1 m dan 2 m nilai kapasitas tekan kolom yang tersusun oleh beberapa batang bambu lebih rendah dibandingkan nilai estimasinya. Nilai estimasi kapasitas kolom menahan tekuk merupakan jumlah nilai kapasitas tekan setiap batang bambu penyusunnya yang telah direduksi dengan faktor tekuk. Pada penelitian ini diameter bambu hitam cukup besar, sehingga pada contoh uji 1 m dan 2 m peristiwa tekuk tidak terjadi. Kolom berukuran 1 m dan 2 m tidak termasuk kolom langsing tetapi masih berada dalam wilayah kolom berukuran sedang, sehingga jumlah komponen penyusun kolom tidak meningkatkan nilai faktor reduksi tekuk secara signifikan. Contoh uji 3 meter sudah mengalami tekuk akibat beban tekan. Hal ini ditunjukkan oleh nilai kapasitas tekan dugaan (Fcr estimate) yang lebih rendah daripada nilai empirisnya (Fcr empiris)., Bamboo is a construction material that abundancely spread in tropical regions. Hitam bamboos (Gigantochloa atroviolacea) have black-colored culm and they have been cultivated in Indonesia. The purpose of this study is to describe the shape of the geometry, the physical properties, and the compressive capacity of bamboo, then to analyze the effect on the number constituent components bamboo multicolumn to the compressive capacity of columns. Bamboo culm specimens were cut to the size of 1 m, 2 m, and 3 m length. The number of specimens of each length are 30, thus the total specimens are 90. The bamboo culms are tied using rope fibers at 40 cm interval to build a multicolumn. Each multiculm are made from 2, 3, or 4 pieces of bamboo culms. The clove hitch methods are applied to tie the components to become a multiculms. Compression test are conducted to 1 m and 2 m specimens using a Universal Testing Machine (UTM) SATEC-Baldwin 30 tons capacity, while the 3 m specimens are tested using UTM 100 tons capacity. Based on the ancova test, the number of bamboo components and the estimated compressive capacity significantly affect the empiric compressive capacity of bamboo multicolumn. Increasing the number of
Keyword: angka kelangsingan, bambu hitam, kapasitas tekan, multi kolom, tekuk, buckling, compressive capacity, hitam bamboo, multiculumn, slenderness ratio

Judul: Pemurnian dan karakterisasi protein inhibitor RNA helikase virus hepatitis C
Abstrak: Hepatitis C virus (HCV) infection is the second most common chronic viral infection in the world with global prevalence. This infection is contribution to chronic hepatitis and liver cirrhosis, often leading to hepatocellular carcinoma. There is no effective drug and vaccine available against HCV. The current standard treatment, a combination of pegylated interferon-α with ribavirin, is limited by its suboptimal response rate in a significant patient population, side effects, and affordability. Therefore, development of effective drug is needed. One approach to find out the candidate of antiviral drug is to discover the inhibitor of enzyme that essential for virus replication, such as RNA helicase. Streptomyces chartreusis 5-095 produce the inhibitor of HCV RNA helicase. The aim of this study was to purify the protein inhibitor which has inhibition activity against ATPase activity of RNA helicase HCV from S. chartreusis 5-095. The supernatant of culture S. chartreusis 5-095 exhibited high inhibiton activity against ATPase activity of RNA helicase HCV (approximately 72%) at 10 days of incubation. The extracellular protein inhibitor was partially purified by procedures of precipitation with ammonium sulfate to 65% saturation and gel filtration (Sephadex G50) using methanol water solution (4:6) as an eluen. The purity of protein inhibitor was monitored by SDS PAGE. The protein inhibitor showed a relative molecular mass were estimated to be 14 kDa and increased the purity 23,08 fold than those of the crude protein. The specific activity and IC50 after purification were 13,1338 U/mg and 0,0767 mg/mL, respectively. The activity of purified protein inhibitor showed its stability over pH range from 5-8 and optimum at pH 7,4. The inhibition activity showed its stability up to 70% at temperature 100 oC. The purified protein inhibitor relatively stable its activity at storage in the range of -20 oC to room temperature for 35 days.
Keyword: