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: Temperature Factor for Correction of Mechanical Properties Wood
Abstrak: Kayu basah bertemperatur tinggi umumnya memiliki sifat mekanis lebih rendah dibandingkan kayu kering bertemperatur rendah sehingga faktor koreksi temperatur diperlukan untuk mempertimbangkan keamanan dan mengurangi resiko bahaya rubuh. Penelitian bertujuan membandingkan sifat fisis dan mekanis kayu konstruksi struktural yang digunakan pada kondisi basah atau kering serta menerima beberapa tingkat suhu. Penelitian juga menghitung nilai faktor temperatur secara empiris. Faktor temperatur didekati dengan perbandingan sifat mekanis kayu pada berbagai kondisi temperatur dan kadar air terhadap sifat mekanis kayu pada kondisi standar. Kondisi standar kayu adalah ketika kadar air berkisar 12–18% dan pada suhu ruang. Hasil penelitian menunjukkan rata-rata nilai faktor temperatur (Ct) suhu 0 ℃, 38 ℃, 45 ℃, dan 60 ℃ untuk kayu Meranti Merah yang digunakan pada kondisi kering berturut-turut adalah 1.03, 1.0, 0.88, 0.86 dan kondisi basah adalah 0.79, 0.64, 0.79, 0.68. Ct kayu Pinus pada kondisi kering rata-rata 0.91, 1.0, 0.95, 0.97 dan kondisi basah adalah 1.07, 0.81, 0.77, 0.87. Nilai Ct penelitian menghasilkan nilai yang bervariasi dibandingkan SNI 7973:2013. Nilai Ct yang lebih kecil dibanding SNI memungkinkan terjadinya bahaya rubuh, sedangkan nilai Ct yang besar lebih konservatif., Woods in high temperature and wet condition generally has lower mechanical properties than woods with lower temperature and dry conditions. Temperature factor is needed to consider safety and to reduce the risk of collapse. This research objective is to compare timber’s physical and mechanical properties in a wet or dry environment and receive several temperature levels. This research also empirically measures the temperature factor, approximated by the ratio of the mechanical properties of wood at various temperatures and moisture content to that of standard conditions. Standard conditions are when the moisture content is 12–18% at room temperature. This research result shows that the average value of temperature factor in 0 ℃, 38 ℃, 45 ℃, and 60 ℃ for Red Meranti used in dry condition consecutively are 1.03, 1.0, 0.88, 0.86 and in wet conditions 0.79, 0.64, 0.79, 0.68. The average Pine wood’s Ct in dry condition are 0.91, 1.0, 0.95, 0.97, and in wet condition are 1.07, 0.81, 0.77, 0.87. The Ct values in this research a greater or lower compared to SNI 7973:2013. The lower Ct value indicates a higher possibility of collapsing, while the higher Ct value means conservative.
Keyword: Temperature factor, Physical properties, Mechanical properties

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.
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