Measurement and analysis of truck transport environment in Brazil

Increasing trade in today's global economy requires packaging to be designed to contain, protect and deliver products without damage during transportation and handling. Vibration forces that occur during transportation are one of the most significant causes of damage during shipping. The objective of this study was to quantify and analyse the vibration that occurs during truck transport in Brazil. The study was done using two types of trucks: small local trucks for local metropolitan distribution areas and larger tractor‐trailers for cross‐country transportation. Ten metropolitan areas in different regions of Brazil were selected for 1‐day trips representing normal delivery. These trips encountered varying road surfaces (asphalt, concrete, stone and dirt). The long distance trips were done on highways that were more than 1200 km long. The vertical vibration levels were higher than the lateral and longitudinal levels as expected. A composite power density spectrum of all trips is provided in this paper to simulate truck transport in Brazil using random vibration test methods. Copyright © 2007 John Wiley & Sons, Ltd.     

A bill of materials-based approach for end-of-life decision making in design for the environment

Re-use, recycling or remanufacturing of products and components are good alternatives for reducing the environmental problems resulting from the huge amounts of waste currently arriving at landfills. A new approach is proposed in this paper for enhancing these alternatives from the earliest stages of product design. Given the product structure (obtained from its bill of materials (BOM)) and the joining and geometrical relationships among the components (obtained from the three-dimensional, computer-aided design representation), a model is proposed that will determine the EOL (EOL) strategy, i.e. the depth of disassembly inside the structure and the final end (re-use, recycle, remanufacture or disposal) for each disassembled part leading to the highest profit. A scatter search (SS) metaheuristic is used to determine the disassembly cost at each level of the BOM. The model presents a number of major improvements with respect to previous research. It addresses the problems of simultaneously determining both the best EOL strategy and the disassembly sequence, as well as allowing removal of components not only over the two or three Cartesian axes and affording the possibility of modifying the encountered strategy in a further step so as to fulfil other business criteria (such as disassembly time, resources availability or maximum waste generation rate).     

The formation of zinc oxide nanoparticles from zinc acetylacetonate hydrate in tert-butanol: A comparative mechanistic study with isomeric C4 alcohols as the media

Spherical ZnO nanoparticles were synthesized via a simple one-pot synthesis route by refluxing an oversaturated solution of zinc acetylacetonate hydrate in tert-butanol. A reaction occurs via a ligand-exchange mechanism, i.e., the dissociation of the acetylacetonate group from the zinc center. The formation of ZnO is slow because of the low nucleophilicity, boiling point and dielectric constant of the medium.The single-crystal ZnO nanoparticles develop near the precursor surface until they reach a critical size and, once diffused into the medium, do not agglomerate, but retain their size and morphology.