Laboratory experiments have recently confirmed that the streamwise particle velocity is largely less than that of the fluid in sediment-laden flows. This velocity lag is investigated analytically in the present study based on the drag force exerting on a particle in the presence of other neighbors. The normalized drag force or the hindrance coefficient is found generally dependent on the partic...

In stingless bees, recruitment of hive bees to food sources involves thoracic vibrations by foragers during trophallaxis. The temporal pattern of these vibrations correlates with the sugar concentration of the collected food. One possible pathway for transferring such information to nestmates is through airborne sound. In the present study, we investigated the transformation of thoracic vibrati...

In the present study, a theoretical model was used to examine factors affecting the filtration characteristics of filters used for respiratory protection. This work was designed to support the particulate filter test requirements established in 1996. The major operating parameters examined in this work include face velocity, fiber diameter, packing density, filter thickness, and fiber charge de...

the local solid flow structure of gas-solid bubbling fluidized bed was investigated to identify and characterize the particle clusters. extensive mathematical calculations were carried out using the energy-minimization multi-scale (emms) approach for evaluating cluster properties including the velocity, the size and the void fraction of clusters in the dense phase of the bed. the results showed...

Unlike pick-and-place manipulations, ne motions strategies generate movements based on sensor information to overcome mechanical and sensory uncertainties. Performing assembly operations with a dexterous hand make high demands on the controller of the robot gripper. Pre-grasping operations are highly dependent on a good position/velocity control. The control strategies for position and velocity...

Two-dimensional Lagrangian trajectories of the inertial particle in helium II are analyzed in the vicinity of the triple vortex structure (i.e. the superfluid vortex and the normal dipole-like vortex structure induced by the mutual friction). It is shown that the vortices in the normal fluid can deflect the particle which otherwise would have collided with the superfluid vortex and, provided th...

Accurate prediction of particle deposition in airliner cabins is important for estimating the exposure risk of passengers to infectious diseases. This study developed a Detached-Eddy Simulation (DES) model with a modified Lagrangian method. The computer model was validated with experimental data for particle deposition in a cavity with natural convection and with air velocity, air temperature, ...

Point scatterers are placed on the real line such that the distances between scatterers are independent identically distributed random variables (stationary renewal process). For a fixed configuration of scatterers a particle performs the following random walk: The particle starts at the point x with velocity v, Iv[ = 1. In between scatterers the particle moves freely. At a scatterer the partic...

This paper considers two additional factors of the widely researched vehicle routing problem with time windows VRPTW . The two factors, which are very common characteristics in realworld, are uncertain number of vehicles and simultaneous delivery and pick-up service. Using minimization of the total transport costs as the objective of the extension VRPTW, a mathematic model is constructed. To so...