Introduction

In this article I will explain the nature of blast forces and their effects on buildings, in a straightforward manner. I will also clarify the difference between blast resistance and blast resilience. Various measures to improve blast resilience in buildings will be described, with the intent that an experienced architect or structural engineer can make informed decisions in the early stages of planning and design.

The premise is consideration of blast loadings in the context of terrorist threats.

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Description of Case

Electrorheological fluids (ERFs) have been described as highly engineered variable-impedance fluids that possess rheological and electrical properties that demonstrate dramatic nonlinear change with an applied electric field.  ERF is a two-phase composite colloidal suspension of electrically polarizable particles dispersed in insulating media.  This article describes an application of low-voltage electrochemical impedance spectroscopy (EIS) to comparative characterization of four different ERFs and a prediction of their performance in ER-activated commercial devices.

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Description of Case

This article attempts to determine the energy and energy losses in a combined hydrogen generation and locomotive transportation system that uses hydrogen fuel (Figure 1). Hydrogen generated by a thermochemical copper-chlorine cycle and stored onboard the locomotive provides power to a prime mover via proton exchange membrane (PEM) fuel cells. The thermodynamic irreversibility of a fuel cell increases as the power rating increases. A problem arises with frequent stops and high acceleration, which increase the hydrogen consumption. Locomotive manufacturers have an interest in the appropriate match of fuel cell type and size, as needed for feasible designs for commercialization. More…

Problem Description

A flotation cell is essentially an agitation-aeration machine. A series of sub- and micro-processes are realized in mechanical flotation machines (sub-aeration type or with external air-blow). Among these the following are included: suspension of the particles in the pulp; reagent mixing; input and dispersion of air into fine bubbles; particle-bubble collisions and attachment only of the hydrophobic particles on the bubbles; formation of particle-bubble aggregates; and raise of the aggregates to the froth. It must also be pointed out that all these sub- and micro-processes take place under high turbulent conditions (Reynolds number 2.4×10⁴ – 7×10⁶). Consequently, turbulence is an important process-determining factor in the operation of flotation machines. More…

Description of Case

We present analytical and simulation models for autonomous vehicle storage and retrieval systems (AVS/RSs). AVS/RS represents a new material handling system (MHS) based on autonomous vehicle (AV) technology. It is automated and used for unit load (UL) storage systems. This new technology has already been used in Europe. We model a particular AVS/RS analytically as semi-open queuing network (SOQN).

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