Micromechanical Behavior of Granular Materials Caused by Particle Shapes under Triaxial Loading

The mechanical behavior was investigated of 3 different particle shapes under different stress paths by setting various intermediate stress ratios. The method of 3D discrete element was applied to research the effect of particle shapes with aspect ratios of ellipsoids and spheres, with both specified by height/width values of 0.4, 0.6, and 1 under different intermediate stress ratios or b values. Each one was used with a single particle shape based on 16 different sizes and random rotation angles. All 3 samples were subjected to a limited isotropic pressure of 100 kPa prior to shearing and constant mean stress using a stress controller. Macro behavior was evaluated based on the stress and strain responses. Micro mechanisms were reported based on the coordination number together with the sliding contract fraction. The fabric tensor of the contact normal, normal contact, and tangential contact forces were examined for the various sample shapes during intermediate loadings of different stress ratios. It was found that anisotropic fabrics and the b values relative to the normal contact force were higher than for the contact normal for all shapes. Furthermore, at the peak stress of each stress path, the specific behavior of normal contact forces varied with the particle shape

Integrated Learning Teacher Professional Development in Primary Schools

AbstractThis study was aimed to compare the skills of teachers to manage integrated learning, before and after the development and the achievement of students who have been integrated learning activities which is higher to 70 percent of the target group; the group consists of 13 teachers, 146 students, with the total number of 159 people. This study was based on the concepts of Kurt Lewin which has four steps: plan, action, observe, and reflect. These following tools were used to collect data: questionnaires, interviews, observation, and tests; they were used to analyze the data for basic statistics, including percentage, mean, standard deviation, data analysis using SPSS, to determine the basic statistics.The results of this research are as follow:The skills of teachers to manage integrated learning before and after the development have resultant statistics at 0.05, significantly.The achievement of students who have been learning integrated activities was risen to 75 percent

The 21-Nucleotide, but Not 22-Nucleotide, Viral Secondary Small Interfering RNAs Direct Potent Antiviral Defense by Two Cooperative Argonautes in Arabidopsis thaliana[W][OA]

This work identifies cooperative action of ARGONAUTE1 and ARGONAUTE2 in virus resistance conferred by 21-nucleotide virus-derived small interfering RNAs (siRNAs). It also reveals that 22-nucleotide viral siRNAs do not guide efficient antiviral defense, demonstrating a qualitative difference between 21- and 22-nucleotide classes of siRNAs in RNA silencing