A Aplicação de um modelo matemático na resolução de um problema de carregamento de paletes

Global competitiveness has been increased significantly in the last decade and, as consequence, companies are always looking for developing better processes in supply chain operations in order to maintain their competitive costs and keep themselves in the business. Logistics operations represent a large part of the product's final cost. Transportation can represent more than fifty percent of final cost sometimes. The solutions for cutting and packing problems consist in simple and low investment actions, as enhancing the arrangement of the transported load in order to decrease both material and room wastes. As per the presented reasons, the objective of this paper is to show and analyze a real application of a mathematical model to solve a manufacturer pallet-loading problem, comparing results from the model execution and the solution proposed by the company studied. This study will not only find the best arrangement to load pallets (which will optimize storage and transportation process), but also to check the effectiveness of existing modeling in the literature. For this study a computational package was used, which consists of a modeling language GAMS with the CPLEX optimization solver and two other existing software in the market, all of them indicating that an accurate mathematical model for solving this kind of problem in a two-dimensional approach is difficult to be found, in addition to a long execution time. However, the study and the software utilization indicate that the problem would be easily solved by heuristics in a shorter execution time

Características do aço API X70 utilizado em tubos de transporte de petróleo e gás

Having in mind that petroleum's history presents a huge growth, the exploration and production areas have been receiving lots of investments, in order to attend the increasing demand for gas and petroleum. Looking through that scenario, new technologies have been evolving in favor of discovering new natural petroleum deposits and act with effectiveness in truly deep waters without giving up the worldwide best operational security practices. The use of rigid pipes in marine installations have been rising quickly and, thanks to this reality, the many storage and pipe launching forms became study objects and are getting improved. The analysis of steel API X70 characteristics, proving that they are suitable for use in pipes developed to transport gas and petroleum is the theme of this presentation. A tensile test was conducted to determine the base metal's mechanical properties, draining's tension, traction's resistance, elasticity's modulus and maximum tension. An aspect that is concerning too is the metallographic analysis, in order to determine the studied iron's microstructure. Results of analyzes showed that the steel has high resistance, with good capacity for deformation and well defined yield point, concluding suitable for the application in question

Estudo do efeito Bauschinger em tubos de aço API 5l x70 aplicados no transporte de petróleo e gás

Despite the growing concern in seeking more sustainable energy sources, oil demand is likely to grow in coming years. To keep up with this growth, the oil industry has increasingly invested in innovation and efficiency. Knowing that, new technologies have been developed to explore deeper waters, without giving up the best practices in worldwide operational safety. The use of rigid pipelines in deepwater offshore facilities is increasing quickly and because of this, the ways of storing and launching pipe have been studied and perfected. In this paper the Bauschinger effect on API 5L X70 steel was analyzed proving that there was a reduction in yield strength when an effort was applied in a previous direction, then an effort was then applied in the opposite direction. To observe this phenomenon, the tensile test was conducted to determine the mechanical properties of the base metal, such as yield stress, tensile strength, elasticity and maximum tensile, so then compare it with the results obtained in the Bauschinger Effect Test. The analysis results showed that the steel had high resistance, with good plastic deformation capacity without failing, well-defined yield point, showing itself appropriate for the operation of oil and gas pipes