Failure Mechanism of True 2D Granular Flows

Most previous experimental investigations of two-dimensional (2D) granular column collapses have been conducted using three-dimensional (3D) granular materials in narrow horizontal channels (i.e., quasi-2D condition). Our recent research on 2D granular column collapses by using 2D granular materials (i.e., aluminum rods) has revealed results that differ markedly from those reported in the literature. We assume a 2D column with an initial height of h0 and initial width of d0, a defined as their ratio (a =h0/d0), a final height of h , and maximum run-out distance of d . The experimental data suggest that for the low a regime (a <0.65) the ratio of the final height to initial height is 1. However, for the high a regime (a >0.65), the ratio of a to (d-d0)/d0, h0/h , or d/d0 is expressed by power-law relations. In particular, the following power-function ratios (h0/h=1.42a^2/3 and d/d0=4.30a^0.72) are proposed for every a >0.65. In contrast, the ratio (d-d0)/d0=3.25a^0.96 only holds for 0.65< a1.5. In addition, the influence of ground contact surfaces (hard or soft beds) on the final run-out distance and destruction zone of the granular column under true 2D conditions is investigated.Comment: 8 page

An Interactive Decision Support System for Scheduling Fighter Pilot Training

The U.S. Air Force is developing Modular Aircraft Support System (MASS) program to replace the current Aerospace Ground Equipment (AGE). AGE supplies electricity, nitrogen, hydraulics and other support equipment to maintenance activities at the flight line. Current AGE makes up one-third of the deployment footprint. AGE is also mostly aircraft specific, and has reliability problems. The MASS alternative focuses on modularity based on a plug-and-play approach. The technological improvements and possible reduction in the footprint make MASS a good alternative. The AF has to determine now, whether MASS can supply similar functionality and decrease the deployment footprint to theater, while not degrading logistics support for the missions. The primary focus in this thesis is to determine the important factors that have impacts on Flying Scheduling Effectiveness (FSE), to decrease the footprint related to the important factors and MASS substitution. The maintenance requirements are examined for the flight line support of 3 types of aircrafts (F16CJ, F15C, and F15E) sent to the theater for the Aerospace Expeditionary Force (AEF) and for 7-days period. This thesis re-engineers the AWESIM model created by O Fearna (1999) and extended by Festejo (2000), into ARENA software. The use of Response Surface Methodology (RSM) with simulation is introduced

COMMUNITY RESPONSE TO ROAD TRAFFIC NOISE IN HANOI-PART I : OUTLINE OF SOCIAL SURVEY AND NOISE MEASUREMENT

Joint Research on Environmental Science and Technology for the Eart