Judul: Physical Properties and Drying Characteristics of Tamiang Bamboo using Oven, Steam Drying, and Air Drying Methods
Abstrak: Bambu merupakan tanaman cepat tumbuh yang termasuk kedalam komoditas hasil hutan bukan kayu. Salah satu jenis bambu yang potensial dimanfaatkan sebagai sedotan bambu adalah bambu tamiang (Schizostachyum blumei). Namun dalam proses pengeringannya terdapat beberapa permasalahan. Tujuan penelitian ini adalah pengaruh berbagai metode pengeringan terhadap sifat fisis dan sifat pengeringan bambu tamiang serta mengidentifikasi serangan dan jenis organisme perusak yang menyerang bambu tamiang pada saat proses pengeringan. Bambu tamiang dikeringkan dengan metode pengeringan oven, uap panas, dan alami. Pengujian sifat fisis yang dilakukan meliputi kadar air, perubahan warna, perubahan dimensi, serta penurunan berat selama proses pengeringan. Sifat pengeringan meliputi laju, waktu, dan cacat pengeringan. Metode pengeringan memberikan pengaruh yang nyata terhadap perubahan warna, perubahan kecerahan, penyusutan dimensi dan laju pengeringan. Sebanyak 17 sampel bambu tamiang yang dikeringkan alami mengalami serangan kumbang (Dinoderus minutus) dan 16 sampel diserang jamur pada bagian ujungnya. Deformasi diameter terjadi pada 9 sampel pengeringan oven, 4 sampel pengeringan uap panas, dan 3 sampel pengeringan alami., Bamboo is a fast-growing plant that falls under the category of non-timber forest products. One type of bamboo that is potentially useful for making bamboo straws is tamiang bamboo (Schizostachyum blumei). However, there are several issues in the drying process. The aim of this research is to study the effect of various drying methods on the physical properties and drying characteristics of tamiang bamboo and to identify the types of organisms that attack tamiang bamboo during the drying process.Tamiang bamboo was dried using oven drying, steam drying, and natural drying methods. The physical properties tested include moisture content, color change, dimensional change, and weight loss during the drying process. The drying characteristics studied include the rate, time, and defects of drying. The drying method has a significant effect on color change, brightness change, dimensional shrinkage, and drying rate. A total of 17 naturally dried tamiang bamboo samples were attacked by beetles (Dinoderus minutus), and 16 samples were attacked by mold at the ends. Diameter deformation occurred in 9 oven-dried samples, 4 steam-dried samples, and 3 naturally dried samples.
Keyword: bamboo straws, Dinoderus minutus, drying, moisture content, Schizostachyum blumei

Judul: The Effect of Condition and Temperature on  Mechanical Properties of Three Bamboo Species
Abstrak: Sifat fisis dan mekanis bambu perlu diketahui jika bambu dimanfaatkan sebagai material konstruksi. Bambu untuk konstruksi eksterior cenderung berhubungan dengan kondisi lingkungan yang sering berubah dan perbedaan suhu harian siang dan malam yang cukup tinggi, sehingga faktor temperatur diperlukan untuk mempertimbangkan keamanan dan mengurangi resiko bahaya rubuh. Penelitian ini bertujuan membandingkan sifat fisis dan mekanis bambu yang menerima beberapa macam temperatur pada kondisi kering dan basah. Penelitian juga menghitung faktor temperatur (Ct) bambu secara empiris dalam kondisi kering dan basah serta membandingkan nilainya dengan SNI 7973:2013. Faktor temperatur (Ct) digunakan sebagai faktor koreksi tegangan ijin (allowable stress) pada analisis struktur konstruksi yang menerima suhu di atas suhu kamar. Nilai faktor temperatur (Ct) diperoleh sebagai rasio nilai sifat mekanis bambu kondisi basah dan kering yang menerima suhu tertentu (0 °C, 38 °C, 45 °C, dan 60 °C) dibandingkan sifat mekanis pada kondisi standarnya (kering bersuhu 38 C). Penelitian ini menggunakan tiga jenis bambu yaitu andong (Gigantochloa psedoarundinaceae), hitam (Gigantochloa atroviolaceae), dan tali (Gigantochloa apus). Pengujian sifat mekanis yang dilakukan meliputi tekan sejajar serat, tarik sejajar serat, geser sejajar serat, lentur tegak lurus serat, dan tarik tegak lurus serat. Hasil penelitian menunjukkan nilai rata-rata pengujian sifat mekanis bambu kondisi kering lebih tinggi dibandingkan kondisi basah. Nilai faktor temperatur (Ct) secara empiris kondisi kering lebih besar dibandingkan SNI 7973:2013. Sementara nilai Ct kondisi basah masih terdapat nilai yang lebih kecil daripada SNI 7973:2013. Nilai Ct empiris yang lebih besar daripada SNI 7973:2013 memiliki kemungkinan bahaya rubuh yang kecil, sehingga masih aman digunakan sebagai faktor koreksi nilai desain acuan bambu., The physical and mechanical properties of bamboo should be measured if bamboo is used as construction materials. Bamboo for exterior construction tends to be associated with changing environmental conditions and daily temperature differences, so the temperature factor is needed to consider safety and reduce the risk of failure hazards. This study aims to compare the physical and mechanical properties of bamboo that accepts various temperatures in dry and wet conditions. The study also calculated the temperature factor (Ct) of bamboo empirically in dry and wet conditions and compared its value with SNI 7973:2013. The temperature factor (Ct) is used as an allowable stress adjustment factor in the construction structural analysis that receive temperatures hotter than the room temperature. The temperature factor value (Ct) was obtained as the ratio of the mechanical properties of bamboo in wet and dry conditions that received certain temperatures (0 °C, 38 °C, 45 °C, and 60 °C) compared to the mechanical properties under standard conditions (dry at 38 C). This study used three bamboo species, namely andong (Gigantochloa psedoarundinaceae), hitam (Gigantochloa atroviolaceae), and tali (Gigantochloa apus). The mechanical properties tests carried out include compression parallel to the fiber, tensile parallel to the fiber, shearing parallel to the fiber, bending perpendicular to the fiber, and tensile perpendicular to the fiber. The results showed that the average value of the mechanical properties of bamboo in dry conditions was higher than in wet conditions. The value of the temperature factor (Ct) empirically in dry conditions is greater than SNI 7973:2013. Meanwhile, the value of
Keyword: bamboo, bamboo construction, condition, mechanical properties, physical properties, temperature factor

Judul: Truncated Stop Loss as a Optimal Solution of Reinsurance Agreement in One-Period Model
Abstrak: Reinsurance is one of risk management efforts of an insurance company, which is called the cedent. Similar with insurance, reinsurance constitutes the cedent to pay the premium. We consider one-period reinsurance model and derive a rule which minimizes the ruin probability of the cedent for a fixed reinsurance premium. Therefore, it is needed to construct an optimal reinsurance agreement for the cedent. The premium is calculated according to four different principles, i.e. economic, generalized zero-utility, Esscher, and mean-variance principles. Stop loss is a reinsurance contract which protect the insurance company for losses that exceed a certain amount. The result of this research shows that a truncated stop loss is an optimal agreement in the class of all reinsurance contracts with various premiums calculated using above mentioned principles.
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