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: Analisis Kekuatan Tekuk Kolom Bambu Tali (Gigantochloa apus (J.A. & J.H. Schultez) Kurz) dengan Variasi Panjang dan Jumlah Batang Penyusun Kolom
Abstrak: Bambu tali berpotensi dijadikan sebagai kolom. Tekuk merupakan titik kritis penyebab kegagalan struktur kolom dalam menahan beban tekan. Penelitian ini bertujuan mengetahui kekuatan tekuk maksimum kolom bambu tali dengan variasi panjang dan jumlah batang penyusun. Bambu tali diperoleh dari pasar komersial di Jl. Raya Dramaga, Bogor, Jawa Barat. Bambu dipotong menjadi ukuran 1, 2, dan 3 m. Pengukuran dimensi berdasarkan BS ISO 19624:2018, sedangkan pengukuran geometri berdasarkan BS ISO 22157:2019. Pengujian sifat fisis meliputi kadar air, kerapatan, dan kerapatan linear, serta pengujian mekanis yaitu kekuatan tekuk kolom bambu tali. Uji lanjut Duncan digunakan untuk membandingkan hasil pengujian tekuk kolom bambu tali dengan variasi panjang dan jumlah batang penyusun kolom. Contoh kolom berukuran 1 m, 2 m, dan 3 m. Pengujian tekuk kolom 1 m mengunakan UTM SATEC-Baldwin berkapasitas 30 ton, sedangkan pengujian tekuk kolom 2 m dan 3m menggunakan alat uji tekan berkapasitas 100 ton. Pengujian tekuk kolom dilakukan dengan memberikan pembebanan secara vertikal pada kolom. Pengolahan data faktor tekuk menggunakan Formula Ylinen’s. Kolom bambu panjang memiliki angka kelangsingan tinggi dan menghasilkan nilai tekuk rendah, sehungga kolom mudah mengalami tekuk. Kolom bambu tali komposisi ganda dua, tiga, maupun empat memiliki nilai kekuatan tekuk lebih tinggi dibandingkan jumlah kekuatan tekuk masing-masing batang penyusunnya karena adanya kerjasama antar komponen penyusun. Peningkatan kekuatan akibat kerjasama antar komponen penyusun ini dapat dinyatakan sebagai repetitive member factor (komponen struktur berulang) yang masih perlu diperhitungkan., Bamboo tali has the potential to be used as a column. Buckling is a critical point that causes the failure of the column structure to withstand compressive loads. This study aims to determine the maximum buckling strength of the bamboo tali column with variations in length and number of comonents. The bamboo tali was obtained from commercial market on Jl. Raya Dramaga, Bogor, West Java. The bamboo is cut into 1, 2, and 3 meters. Dimensional measurements are based on BS ISO 19624:2018, while geometric measurements are based on BS ISO 22157:2019. Physical properties tests include moisture content, density, and linear density, as well as mechanical testing, namely the buckling strength of the bamboo tali column. Duncan's further test was used to compare the results of the buckling test of bamboo tali columns with variations in length and number of components making up the column. The column test speciments are 1 m, 2 m, and 3 m. The 1 m sized columns are tested using UTM SATEC-Baldwin 30 tons capacity, while the 2 m and 3 m sized column were tested using compressive testing machine 100 tons capacity. The column buckling test is carried out by applying vertical loading to the column. Buckling factor data processing using Ylinen's Formula. Long bamboo columns have a high slenderness rate and produce a low buckling value, so that the column is prone to buckling. The the buckling strength of bamboo multicolumns are higher than the sum of single colunms buckling strengths because of the cooperation between the column’s components. The strength improvement because of the column’s components cooperation can be determined as repetitive member factor which should be considered.
Keyword: angka kelangsingan, kolom, multikolom, tali, tekuk, slenderness ratio, column, multicolumns, tali, buckling

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.
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