Warehouse Storing and Collecting of Parts

This report deals with reducing the high costs resulting from the wear and tear of the fork-lifts used to store or collect items in a warehouse. Two problems were identified and addressed separately. One concerns the way items should be stored or collected at storage locations on the shelves of one corridor. The other problem seeks for an efficient way to define which fork-lift should operate on each corridor, and the order by which the fork-lifts should visit the corridors. We give to both problems formulations that fit in the framework of combinatorial optimization

Meat yield of Bolinus brandaris (Gastropoda: Muricidae): comparative assessment of the influence of sex, size and reproductive status

The present study assessed the influence of sex, size and reproductive status on the meat yield (soft tissues proportion) of the purple dye murex (Bolinus brandaris) from the Ria Formosa lagoon (southern Portugal). During one year of monthly sampling (October 2008-September 2009), average meat yield of B. brandaris was 40.5 +/- 6.1% (range: 25.8-56.1% wet weight), with no significant differences between sexes. Relationships established between specimen size and soft parts weight indicated that both shell length and total weight are excellent indicators of meat yield. Significant differences in meat yield between size classes further reinforced the trend of increasing meat yield during ontogeny. Meat yield exhibited significant monthly variation and a similar temporal trend in both sexes, which were directly related to the reproductive status. Meat yield of B. brandaris was compared with that of other muricid species and the marked influence of the reproductive status on meat yield prompted a comparative assessment of the spawning season and peak of three sympatric muricids (B. brandaris, Hexaplex trunculus and Stramonita haemastoma). Overall, these findings have implications at diverse levels, including the management, regulation and inspection of this fishing/ harvesting activity and the commercialization and consumption of this seafood product.postdoctoral grant [SFRH/BPD/26348/2006]; Fundacao para a Ciencia e Tecnologia (FCT - Portugal); Fisheries Operational Programme (PROMAR); European Fisheries Fund [EFF 2007-2013]info:eu-repo/semantics/publishedVersio

Análise experimental do comportamento de paredes de alvenaria de pedra não reforçada sob acções cíclicas no plano

Com o presente trabalho pretende-se efectuar a avaliação experimental do comportamento de paredes de alvenaria de pedra não reforçada, com diferente aparelho das pedras em alçado, submetidas a acções horizontais cíclicas no plano. A análise dos resultados experimentais abrange a caracterização dos mecanismos de rotura, padrões de fendilhação, e a determinação da resistência última das paredes a acções horizontais cíclicas. Adicionalmente, realiza-se a discussão da resposta em termos de diagramas força-deslocamento, bem como o estudo comparativo da resistência e rigidez lateral para os dois tipos de paredes ensaiadas.Empresa Augusto Ferreira. Bettor MBT

The design and performance of high-performance perforated fired masonry bricks

Fire perforated clay masonry units have been extensively used through years in masonry structures, particularly in masonry walls both for loadbearing and non-loadbearing purposes (partition walls and enclosures). The location of the masonry walls as external enclosure brings some physical requirements, which together with mechanical requirements are the basis of the design of hollow clay bricks. This chapter provides an overview of the design requirements and design concepts of hollow clay bricks, together with some recent trends arising in the framework of obtaining more sustainable constructive materials. It discusses the main issues related to the mechanical performance of the units and of the masonry assemblages under distinct loading conditions. As often the unreinforced hollow clay masonry is built in seismic prone regions, an emphasis is given to the seismic behavior of hollow clay brick masonry under combined vertical and lateral in-plane loading, being discussed the main seismic performance parameters

Modern masonry structures and earthquakes : reinforced or unreinforced?

The evolution of structural masonry is briefly reviewed, from old thrust line behavior to modern global behavior using shear walls. For modern structural masonry, the use of unreinforced, confined and reinforced masonry is addressed in seismic areas. A first focus is given to recent approaches towards the safety assessment of unreinforced masonry buildings and their performance in shaking table tests. Subsequently, building systems for modern masonry structures recently developed and tested at University of Minho are presented, one based on lightweight concrete blocks and another based on normal concrete blocks. The experimental and numerical work carried out is discussed and conclusions on the performance of the systems are given

Evaluation of the in-plane seismic performance of stone masonry walls

Although traditional historic masonry walls can be viewed as unsuitable structures to undergo seismic actions, they, in fact, exist and frequently represent the major structural elements of ancient buildings. Brick unreinforced masonry walls have been widely studied both from experimental and numerical point of view, but scarce experimental information is available for stone masonry walls. Therefore, the present work aims at increasing the insight about the behavior of typical ancient masonry walls under cyclic loading. Besides the strength and stiffness characterization, information about nonlinear deformation capacity is provided in terms of ductility factor and lateral drifts, which represent a step forward for the new concepts of performance based design

Influence of aggregates grading and water/cement ratio in workability and hardened properties of mortars

Mortar is the material responsible for distribution of stresses in masonry structures. Knowledge about the fresh and hardened properties of mortar is fundamental to ensure a good performance of masonry walls. Water/cement ratio and aggregates grading are among several variables that influence physical and mechanical behaviour of mortars. An experimental program is presented in order to evaluate the influence of aggregates grading and water/cement ratio in workability and hardened properties of mortars. Eighteen compositions of mortar are prepared using three relations cement:lime:sand, two types of sand and three water/cement ratios. Specimens are analyzed through flow table test, compressive and flexural strength tests. Results indicate that the increase of water/cement ratio reduces the values of hardened properties and increases the workability. Besides, sands grading has no influence in compressive strength. On the other hand, significant differences in deformation capacity of mortars were verified with the variation of the type of sand. Finally, some correlations are presented among hardened properties and the compressive strength.This work was partly supported by contract DISWALL - "Development of innovative systems for reinforced masonry walls" - COOP-CT-2005-018120 from the European Commission. The first author was supported by the Programme Al beta an, the European Union Programme of High Level Scholarships for Latin America, Scholarship No. E06D100148BR