233 research outputs found
Process transparency on construction sites : examples from construction companies in Brazil
Process transparency is the core concept in Visual Management (VM), which is one of the founding blocks of the Toyota Production System. This paper presents the
preliminary results of a collaborative research conducted between Brazil and the UK, as part of a research effort focused on the application of Visual Management in
construction. How process transparency is realized on construction sites is the main research question of the paper. The use of this concept and the implementation of the
transparency theory were investigated through multiple case studies, carried out in nine different construction companies. The findings are explained through six theoretical transparency increasing approaches. The affecting parameters in the application of, the management’s perception of and several methods in process
transparency in construction were identified. Further work, especially exploring the functions of process transparency on construction sites and reflecting the worker perception of the issue, is necessary to elaborate the process transparency concept
The smectitic minerals in a bentonite deposit from melo (Uruguay)
International audienceA nearly monomineralic 1.5 m thick bentonite bed sampled in Melo (Uruguay) appears to be a pure high-charge montmorillonite: [Si3.94 Al0.06] (Al1.40 Fe 3+ 0.11 Ti0.02 Mg0.49 Mn0.01) O10 (OH)2 Na0.01 K0.08 Ca0.18. However, contrasting swelling behaviors have been evidenced by fitting the experimental X-ray diffraction patterns recorded on oriented preparations of the same sample in different saturation states. According to the expandability of the layers in the Ca-, K- and K-Ca-saturated (that is saturated first with K + and subsequently with Ca2+) states, three "layer types" were defined. Low-, intermediate-, and high-charge layers are fully, partly, and not expandable, respectively, after K-saturation. Collapse of high-charge layers is not reversible after subsequent Ca-saturation, most likely because of tetrahedral substitutions. These three different layer types are segregated in two distinct randomly interstratified mixedlayer phases. TSA and CEC are shown to depend on the interlayer cation composition
REVISÃO DA EXTENSÃO AREAL E DO VOLUME DA FORMAÇÃO SERRA GERAL, BACIA DO PARANÁ, AMÉRICA DO SUL
In the discussion of the origin of continental flood basalt provinces, one of the most important constraints is the volume of the mobilized magma. Concerning the Serra Geral Formation in the Paraná Basin (South America), most authors cite an actual areal extent of 1,200,000 km2 and a volume of approximately 800,000 km3 . The same volume is often used for the Paraná-Etendeka Continental Flood Basalt Province, from which the Serra Geral Formation is the major part. We investigated the precision of these numbers through a complete historical review of their origin. We found that the areal extent cut off of 1,200,000 km2 is only an estimate made in 1934, and that the volume cut off of 800,000 km3 aroused using this areal extent estimate and an estimate of a mean thickness of 650 m of the flows made in 1966. Using a new map, we found that the area covered by the volcanic rocks in the Paraná Basin is of only 917,000 km2 (+- 15,000 km2 ). With isopach maps of 1987 and 1990, we calculated the volume of the extrusive rocks to be of at least 450,000 km3 and of the intrusive sill-type bodies to be of at least 112,000 km3 . With these estimates, the volume of the Serra Geral Formation should be considered to be of more than 600,000 km3 . For the Paraná-Etendeka Continental Flood Basalt Province as a whole, a volume of at least 1,700,000 km3 should be considered. A discussão sobre a origem das Províncias de Basaltos de Platô Continentais tem como um de seus elementos mais importantes o volume do magma mobilizado. Em relação às rochas da Formação Serra Geral na Bacia do Paraná (América do Sul), a maioria dos autores cita uma extensão de 1.200.000 km2 e um volume de aproximadamente 800.000 km3 . O mesmo volume é usado frequentemente para a Província de Basaltos de Platô Continental Paraná-Etendeka, da qual a Formação Serra Geral constitui a maior parte. Nós investigamos a precisão desses números através de uma revisão histórica completa acerca de sua origem. Verificamos que o valor relativo à extensão, de 1.200.000 km2 , é apenas uma estimativa apresentada em 1934 e que o volume de 800.000 km3 foi obtido multiplicando este valor de extensão por uma estimativa da espessura média dos derrames de lava de 650 metros apresentada em 1966. Usando um mapa recente, verificamos que a área coberta por rochas vulcânicas na Bacia do Paraná é de apenas 917.000 km2 (+- 15.000 km2 ). Através de mapas de isópacas de 1987 e 1990, calculamos o volume das rochas extrusivas como sendo de pelo menos 450.000 km3 e que o volume referente aos corpos intrusivos do tipo sill é de pelo menos 112.000 km3 . Através destas estimativas, o volume de rochas da Formação Serra Geral deve ser considerado como sendo superior a 600.000 km3 . A Província de Basaltos de Platô Continental Paraná-Etendeka como um todo possui um volume de no mínimo 1.700.000 km3
Use of Green Sulla Forage for Feeding. 1. Effects on Lamb Growth and Gastrointestinal Nematode Parasite Infestation
Recent studies have shown that some forage legumes containing condensed tannins (CT), such as sulla (Hedysarum coronarium L.), can reduce the gastrointestinal nematode burden in sheep (Niezen et al., 1998) and increase post-ruminal protein availability (Waghorn et al., 1994). This study aimed to evaluate the anthelmintic and nutritional properties of sulla forage in relation to its CT content. Thus, the growth performance and the level of nematode infestation of lambs fed sulla were compared with those of lambs fed ryegrass (Lolium multiflorum Lam. subsp. wersterwoldicum), lacking in CT
Efeito de diferentes concentrações de citocinina na organogênese de cotilédones de pinhão manso.
Geometry and Joint Systems for Lattice-Based Reconfigurable Space Structures
We describe analytical methods for the design of the discrete elements of ultralight lattice structures. This modular, building block strategy allows for relatively simple element manufacturing, as well as relatively simple robotic assembly of low mass density structures on orbit, with potential for disassembly and reassembly into highly varying and large structures. This method also results in a structure that is easily navigable by relatively small mobile robots. The geometry of the cell can allow for high packing efficiency to minimize wasted payload volume while maximizing structural performance and constructability. We describe the effect of geometry choices on the final system mechanical properties, manufacturability of the components, and automated robotic constructability of a final system. Geometry choices considered include building block complexity, symmetry of the unit cell, and effects of vertex, edge, and face connectivity of the unit cell. Mechanical properties considered include strength scaling, modulus scaling, and structural performance of the joint, including proof load, shear load, mass, and loading area; as well as validation and verification opportunities. Manufacturability metrics include cost and time, manufacturing method (COTS versus custom), and tolerances required. Automated constructability metrics include local effects of loads imparted to the structure by the robot and assembly complexity, encompassing the ability of the robot to clamp and number of placement motions needed for assembly
Efeito da luz durante germinação e incubação de cotilédones de Jatropha Curcas L. na organogênese.
Avaliação do estímulo de diferentes concentrações de citocininas em ápices e cotilédones de mamona (Ricinus communis L.)cv BRS-ENERGIA.
Organogênese indireta a partir de cotilédones de mamona (Ricinus communis L.) cv BRS-ENERGIA.
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