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: The effect of connection type, the position of testing, and the distance of connection to the strength of tali bamboo (gigantochloa apus kurzt)
Abstrak: Gigantochloa apus Kurzt yang dikenal dengan bambu tali atau bambu apus adalah salah satu jenis bambu yang mudah ditemukan dan banyak dimanfaatkan oleh masyarakat, khususnya masyarakat pedesaan. Pemanfaatan bambu tali sebagai bahan konstruksi belum banyak digunakan, karena masih kurangnya dukungan data penelitian mengenai karakteristik bambu tali serta modifikasi produk bambu tali dalam bidang konstruksi. Tujuan dari penelitian ini adalah menganalisis karakteristik balok bambu tali menggunakan alat sambung kombinasi pasak dan tali, serta alat sambung baut, pada posisi pengujian horizontal dan vertikal, dengan tiga variasi jarak sambungan (50, 100, dan 150) cm. Prosedur pengujian sifat lentur balok bambu menggunakan standar pengujian ISO 22157-1:2004 tentang pengujian buluh bambu secara full scale. Nilai lentur diperoleh menggunakan persamaan ASTM D-198 dan persamaan ISO 22157-1:2004. Hasil penelitian menunjukkan rerata nilai KA pada bambu tali sebesar 25.70% sampai 40.81% dan rerata nilai kerapatan contoh uji produk sebesar 0.67 g/cm3. Hasil uji mekanis menunjukkan rerata nilai MOE pada balok bambu berada pada selang 93425.16 – 165000.14 kg/cm2 (ASTM D-198) serta 166761.32 - 714347.73 kg/cm2 (ISO 22157-1:2004) dan rerata nilai MOR balok bambu berada pada selang nilai 236.48 – 571.29 kg/cm2 (ASTM D-198) serta 260.69 - 711.09 kg/cm2 (ISO 22157-1:2004). Hasil penelitian menunjukkan bahwa balok bambu perlakuan sambungan baut pada posisi pengujian horizontal merupakan balok bambu dengan perlakuan terbaik. Berdasarkan hasil penelitian ini balok bambu dapat dimanfaatkan sebagai bahan konstruksi ringan., Gigantochloa apus Kurzt known as Tali bamboo or Apus bamboo is one type of bamboo that are easy to find by the people, especially the rural communities. Utilization of bamboo as a construction material has not been widely used because the lack of data about the characteristics of bamboo and it’s modifications of tali bamboo products in construction sector. The purpose of this study is to analyze the characteristics of tali bamboo using combination of dowell and rope connection, and bolt, at horizontal and vertical position, with three distance of connection variation (50, 100, and 150 cm). The bending test method was used by ISO 22157- 1:2004 for full scale test of bamboo’s culm. Bending value was obtained from the equation of ASTM D-198 and ISO 22157.1:2004. The result showed that the average of Moisture Content (MC) of Tali bamboo in range 25.99% to 36.62% and the density was 0.67 g/cm3. The results of mechanical test showed that the mean value of tali bamboo on MOE were 93425.16 – 165000.14 kg/cm2 (ASTMD 198) and 166761.32 - 714347.73 kg/cm2 (ISO 22157-1:2004) and the MOR were 236.48 – 571.29 kg/cm2 (ASTMD 198) and 260.69 - 711.09 kg/cm2 (ISO 22157-1:2004). Based on the results of this research, this bamboo beam can be used as a respectively construction material.
Keyword: Gigantochloa apus Kurzt, sambungan baut, sambungan pasak, sambungan tali, sifat fisis, sifat mekanis

Judul: A Continuous Vaccination Strategy in the SVIR Epidemic Model
Abstrak: Vaccination is conducted to minimize the spread of a disease. The vaccination is usually done several times within a fixed time interval. In the SVIR model, it is assumed that individuals do not get immediate immunity following a vaccination program. So according to process of vaccination on SVIR model, there are two strategies, i.e. the continuous vaccination strategy (CVS) and the pulse vaccination strategy (PVS). In this study, only the CVS strategy in epidemic model SVIR is considered. Results of the study indicate that dynamics of the CVS system depends on the basic reproductive number. If the basic reproductive number is less than one, then the disease-free fixed point is asymptotically stable. It means that the disease will eventually disappear from the population. Conversely, if the basic reproductive number is greater than one, then the endemic fixed point is asymptotically stable, which means that the disease will remain exist in the population. Simulation result shows that the vaccination would minimize the spread of disease by reducing the basic reproductive number. If the time for the vaccinated recipients to obtain the immunity, as well as a possibility of vaccinated recipients to be infected are neglected, then the disease will be eradicated. This condition is called an over-evaluating effect of vaccination.
Keyword: