this study aims to deal with a more realistic combined problem of project scheduling and material ordering. the goal is to minimize the total material holding and ordering costs by determining the starting time of activities along with material ordering schedules subject to some constraints. the problem is first mathematically modelled. then a hybrid simulated annealing and genetic algorithm is...

the abrasive flow machining technique uses a self-deforming tool, an abrasive laden media that is passed back and forth in the passage geometry of the hollow workpiece with the assistance of two hydraulically operated cylinders placed opposite to each other. the material is removed by abrasion generating finer surfaces in the area where flow is restricted. but this method has a low material rem...

This paper presents a hybrid cylinder/wire drive parallel arm. Its workspace is analyzed for the application of manipulating heavy materials in construction and ship building industries. The conventional Stewart platform and a multiple wire drive mechanism are compared, and hybrid drive mechanisms are considered in analysis and designing. The total number of cylinder and wire is fixed to seven ...

Both fullerenes and single-walled carbon nanotubes (SWNTs) exhibit many advantageous properties. Despite the similarities between these two forms of carbon, there have been very few attempts to physically merge them. We have discovered a novel hybrid material that combines fullerenes and SWNTs into a single structure in which the fullerenes are covalently bonded to the outer surface of the SWNT...

Material properties and geometry are two important design parameters which their effects should be considered in a crashworthiness analysis. In this paper, the axial impact of metallic and hybrid energy absorbing thin-walled tubes with poly-gonal cross-section is simulated using LS-DYNA software. The combined effects of changing the geometry and material properties on the mass specific energ...

In this article, the state-of-the-art multi-wave and hybrid imaging techniques in the field of nondestructive evaluation and structural health monitoring were comprehensively reviewed. A new direction for assessment and health monitoring of various structures by capitalizing the advantages of those imaging methods was discussed. Although sharing similar system configurations, the imaging physic...