We report on the design, modeling and fabrication by multi-photon polymerization of a complex medical fluidic device. The physical dimensions of the built micro-valve prototype are compared to those of its computer-designed model. Important fabrication issues such as achieving high dimensional resolution and ability to control distortion due to shrinkage are presented and discussed. The operati...

We consider an overloaded multi-server multi-class queueing model where customers may abandon while waiting to be served. For class i, service is provided at rate μi , and abandonment occurs at rate θi . In a many-server fluid regime, we show that prioritizing the classes in decreasing order of ciμi/θi asymptotically minimizes an ergodic holding cost, where ci denotes the equivalent holding cos...

Corona discharges exist in a variety of forms (streamer and diffuse, steady and pulsed) and have multi-scale nature (in both space and time). High spatial resolution is required to analyze ionization fronts, streamers and Trichel pulses observed in corona discharges. We present multi-dimensional simulations of corona and glow discharges with adaptive Cartesian mesh using fluid models. Effects o...

this paper presents a new mathematical model for a bi-objective job shop scheduling problem with sequence-dependent setup times that minimizes the weighted mean completion time and the weighted mean tardiness time. for solving this multi-objective model, we develop a fuzzy multi-objective linear programming (fmolp) model. in this problem, a proposed fmolp method is applied with respect to the o...

in this paper, firstly by using a mixed linear programming a new model of locating facilities with limited capacity is presented to design a closed-loop supply chain in a multi-product and multi-period mode. then, using a robust optimization approach, the proposed model decreases in non-deterministic expansion. the results show that the proposed model can handle facility capacity in a closed lo...

A multi-class many-server system is considered, in which customers are served according to a non-preemptive priority policy and may renege while waiting to enter service. The service and reneging time distributions satisfy mild conditions. Building on an approach developed by Kaspi and Ramanan, the Law-of-Large-Numbers many-server asymptotics are characterized as the unique solution to a set of...

A gas kick simulation model for deep-water horizontal well with diesel-based drilling fluid is presented in this paper. This model is mainly based on the mass, momentum, and energy conservation equations. The unique aspect of this model is the fluid-gas coupling and the change of mud properties after the gas influx from the formation. The simulation results show that the gas in an annulus disso...

A dam under seismic excitation contains several multi-physics coupled systems that are of interest in computational modeling. The greatest heterogenous coupled systems are the fluid-structure interaction between the fluid and the dam as well as the fluid and the soil. In addition, there is a region near the dam that is subject to bulk cavitation, where the fluid pressure drops below the vaporiz...

Full numerical simulations of three-dimensional flows of two or more immiscible fluids of different densities and viscosities separated by a sharp interface with finite surface tension are discussed. The method used is based on a finite difference approximation of the full Navier-Stokes equations and explicit tracking of the interface between the fluids. Preliminary simulations of the Rayleigh-...