830 resultados para wear strengthening and toughening


Relevância:

100.00% 100.00%

Publicador:

Resumo:

RESUMO: A gestão do sistema educacional brasileiro foi significativamente descentralizada pela Constituição Federal de 1988 (CF/88) ao reconhecer a autonomia entre os três níveis federativos e ao introduzir o princípio da gestão democrática da Educação. Assim motivado, o sistema educacional baiano iniciou sua reforma em 1999, através do Programa Educar para Vencer, tendo como referencial oferecer maiores níveis de autonomia e capacidade local de gestão para as unidades escolares públicas no Estado da Bahia. Para fortalecer a gestão educacional, o Governo, através do Projeto Fortalecimento da Gestão e Autonomia Educacional (PFGAE), introduziu o planejamento estratégico para melhorar a qualidade de ensino como ferramenta de gestão das escolas públicas estaduais baianas, apoiado em um amplo programa de financiamento para a sua implementação. ABSTRACT: The administration of Brazil’s educational system was significantly decentralized by the Federal Constitution of 1988 (CF/88) when it recognized the autonomy between the three federative levels and introduced the education’s democratic management principle. Motivated by that, Bahia’s educational system started its reform in 1999, through the “Educar para Vencer” (Educate to Win) program, having as its aim to offer bigger levels of autonomy and administrative local capacity for public schools in the State of Bahia. To strengthen the educational administration, the government, via the Administration Strengthening and Educational Autonomy Project (PFGAE), introduced the strategic planning to improve the quality of education as a management tool of the state schools of Bahia, supported by a wide financing program for its implementation.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In the UK, public expenditure on transport infrastructure is nearly £6 billion for the past few years. Over £500 million per year were spent on bridge assessment and strengthening and reducing the backlog of road requiring maintenance. A further £200 million a year will be spent on keeping the safe operation of the network and efficiently through day to day maintenance, lighting and signing . The Department of Transport is planning to extend private sector experience in road management and operation by introducing Design, Build, Finance and Operate (DBFO) This paper investigates the different ways of financing road transport infrastructure including road pricing, private finance in transport infrastructure, the role of the private sector, Design, Build, Finance and Operate (DBFO) schemes, the benefits and problems of such schemes. The paper considers planning gain as a means of financing transport infrastructure with examples of developers to fund link road building and improvements to the local planning system

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Dog-in-a-Doublet Bridge Reconstruction Scheme integrates the interdisciplinary design to provide solution for different needs: to provide a crossing to carry the new 40-tonne loading requirement, to improve the visibility of the substandard junction, and within the funding available. The management of the project involves the co-ordination of different authorities, statutory undertakers and other bodies. At certain stages, there were negotiations with RSPB on the restriction of construction period from July to November. After the re-assessment of the environmental impact of the construction on the breeding and wintering birds, the restrict was waived. As the bid for the assessment, strengthening and structural maintenance of bridges in the Cambridgeshire County Council Transport Policies and Programme No. 21 (1995/96) for Dog-in-a-Doublet Bridge Reconstruction Schemes was unsuccessful to attract the Transport Supplement Grant (TSG). A series of temporary measures had to be undertaken until funding is available for its replacement.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A poleward shift of the mid-latitude storm tracks in response to anthropogenic greenhouse-gas forcing has been diagnosed in climate model simulations1, 2. Explanations of this effect have focused on atmospheric dynamics3, 4, 5, 6, 7. However, in contrast to storm tracks in other regions, the North Atlantic storm track responds by strengthening and extending farther east, in particular on its southern flank8. These adjustments are associated with an intensification and extension of the eddy-driven jet towards western Europe9 and are expected to have considerable societal impacts related to a rise in storminess in Europe10, 11, 12. Here, we apply a regression analysis to an ensemble of coupled climate model simulations to show that the coupling between ocean and atmosphere shapes the distinct storm-track response to greenhouse-gas forcing in the North Atlantic region. In the ensemble of simulations we analyse, at least half of the differences between the storm-track responses of different models are associated with uncertainties in ocean circulation changes. We compare the fully coupled simulations with both the associated slab model simulations and an ocean-forced experiment with one climate model to establish causality. We conclude that uncertainties in the response of the North Atlantic storm track to anthropogenic emissions could be reduced through tighter constraints on the future ocean circulation.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The Asian summer monsoon is a high dimensional and highly nonlinear phenomenon involving considerable moisture transport towards land from the ocean, and is critical for the whole region. We have used daily ECMWF reanalysis (ERA-40) sea-level pressure (SLP) anomalies to the seasonal cycle, over the region 50-145°E, 20°S-35°N to study the nonlinearity of the Asian monsoon using Isomap. We have focused on the two-dimensional embedding of the SLP anomalies for ease of interpretation. Unlike the unimodality obtained from tests performed in empirical orthogonal function space, the probability density function, within the two-dimensional Isomap space, turns out to be bimodal. But a clustering procedure applied to the SLP data reveals support for three clusters, which are identified using a three-component bivariate Gaussian mixture model. The modes are found to appear similar to active and break phases of the monsoon over South Asia in addition to a third phase, which shows active conditions over the Western North Pacific. Using the low-level wind field anomalies the active phase over South Asia is found to be characterised by a strengthening and an eastward extension of the Somali jet whereas during the break phase the Somali jet is weakened near southern India, while the monsoon trough in northern India also weakens. Interpretation is aided using the APHRODITE gridded land precipitation product for monsoon Asia. The effect of large-scale seasonal mean monsoon and lower boundary forcing, in the form of ENSO, is also investigated and discussed. The outcome here is that ENSO is shown to perturb the intraseasonal regimes, in agreement with conceptual ideas.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

AOGCMs of the two latest phases (CMIP3 and CMIP5) of the Coupled Model Intercomparison Project, like earlier AOGCMs, predict large regional variations in future sea level change. The model-mean pattern of change in CMIP3 and CMIP5 is very similar, and its most prominent feature is a zonal dipole in the Southern Ocean: sea level rise is larger than the global mean north of 50°S and smaller than the global mean south of 50°S in most models. The individual models show widely varying patterns, although the inter-model spread in local sea level change is smaller in CMIP5 than in CMIP3. Here we investigate whether changes in windstress can explain the different patterns of projected sea level change, especially the Southern Ocean feature, using two AOGCMs forced by the changes in windstress from the CMIP3 and CMIP5 AOGCMs. We show that the strengthening and poleward shift of westerly windstress accounts for the most of the large spread among models in magnitude of this feature. In the Indian, North Pacific and Arctic Oceans, the windstress change is influential, but does not completely account for the projected sea level change.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We present an ultimatum wage bargaining experiment showing that a trade union facilitating non-binding communication among workers, raises wages by simultaneously increasing employers’ posted offers and toughening the bargaining position of employees, without reducing overall market efficiency.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Silicon nitride has demonstrated to be a potential candidate for clinical applications because it is a non-cytotoxic material and has satisfactory fracture toughness, high wear resistance and low friction coefficient. In this paper, samples of silicon nitride, which were kept into rabbits` tibias for 8 weeks, and the adjacentbone tissue were analysed by scanning electron microscopy in order to verify the bone growth around the implants and the interaction between the implant and the bone. Bone growth occurred mainly in the cortical areas, although it has been observed that the newly bone tends to grow toward the marrow cavity. Differences were observed between the implants installed into distal and proximal regions. In the first region, where the distance between the implant and the cortical bone is greater than in the proximal region, the osteoconduction process was evidenced by the presence of a bridge bone formation toward the implant surface. The results showed that silicon nitride can be used as biomaterial since the newly bone grew around the implants. (c) 2007 Elsevier Inc. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This thesis focuses on the tribological performance of tool surfaces in two steel working operations, namely wire drawing and hot rolling. In all forming operations dimensions and surface finish of the products are of utmost importance. Forming basically includes three parts – forming conditions excluded – that may be changed; work material, tool and (possibly) lubricant. In the interface between work material and tool, the conditions are very aggressive with – generally or locally – high temperatures and pressures. The surfaces will be worn in various ways and this will change the conditions in the process. Consequently, the surface finish as well as the dimensions of the formed product may change and in the end, the product will not fulfil the requirements of the customer. Therefore, research and development in regard to wear, and consequently tribology, of the forming tools is of great interest. The investigations of wire drawing dies focus on coating adhesion/cohesion, surface characteristics and material transfer onto the coated steel both in laboratory scale as well as in the wire drawing process. Results show that it in wire drawing is possible to enhance the tribological performance of drawing dies by using a lubricant together with a steel substrate coated by a polished, dual-layer coating containing both hard and friction-lowering layers. The investigations of hot rolling work rolls focus on microstructure and hardness as well as cracking- and surface characteristics in both laboratory scale and in the hot strip mill. Results show that an ideal hot work roll material should be made up of a matrix with high hardness and a large amount of complex, hard carbides evenly distributed in the microstructure. The surface failure mechanisms of work rolls are very complex involving plastic deformation, abrasive wear, adhesive wear, mechanical and thermal induced cracking, material transfer and oxidation. This knowledge may be used to develop new tools with higher wear resistance giving better performance, lower costs and lower environmental impact.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The surface failure characteristics of different work roll materials, i.e. High Speed Steel, High Chromium Iron and Indefinite Chill Iron, used in the finishing stands of a hot strip mill have been investigated using stereo microscopy, 3D optical profilometry, scanning electron microscopy and energy dispersive X-ray spectroscopy. The results show that the surface failure mechanisms of work rolls for hot rolling are very complex, involving plastic deformation, abrasive wear, adhesive wear, mechanical and thermal induced cracking, material transfer and oxidation. Despite the differences in chemical composition and microstructure, the tribological response of the different work roll materials was found to be strongly dependent on the material microstructure and especially the presence and distribution of microstructural constituents, such as the different carbide phases and graphite (in the case of Indefinite Chill Iron). Cracking and chipping of the work roll surfaces, both having a negative impact on work roll wear, are strongly influenced by the presence of carbides, carbide networks and graphite in the work roll surface. Consequently, the amount of carbide forming elements as well as the manufacturing process must be controlled in order to obtain an optimised microstructure and a predictable wear rate.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The objective of this essay was to verify if the practices of local development in these small towns (population under 20.000 inhabitants) of Lavra¿s small region have contributed to the formation and/or strengthening of social network. The work was conducted from a theoretical discussion about local development, citizenship, local development with citizenship and social network. Afterward interviews were made semi-structured with a sample formed of 54 citizens of six towns of Lavra¿s small region in Minas Gerais. The speech analysis was used in the treatment of the dates. As results, considering the strengthening and formation of social network, it is possible to say: about the strengthening, that there is not a possibility, because the social networks structured as we understand it, do not exist or are still to embryonic, prevailing, in the formation towns, the pyramidal structure. And about the formation, it is notable that there are more negative aspects than positive to the development of these networks, however some initiative point out to the possibilities of creation. Therefore, we can conclude that the practice of local development contribute, still, in a very incipient and limited manner to the formation of social networks in the state¿s town. Incipient because the identified initiatives that points towards the creation are recent and are still in a structure stage; and limited because there are too many negative aspects that make the construction difficult.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

O processo de centralização vigente no setor saúde desenvolveu-se utilizando-se fortemente o mecanismo de desconcentração. A análise das três propostas de reorganização do setor saúde, no período de 1983 a 1990, aponta para uma mudança de estratégia no mecanismo de desconcentração. Anteriormente, os órgãos centrais dispunham de estruturas desconcentradas atuando nos níveis intermediários e locais. A partir de 1983 observa-se a tendência da atuação dos níveis intermediários e locais como instâncias desconcentradas do nível central. Portanto, a desconcentração é um processo em curso no setor. A desconcentração pode assumir sentidos distintos, isto é, pode ser uma estratégia de fortalecimento e atualização da centralização ou pode ser uma estratégia de fortalecimento dos níveis intermediários e locais, e, portanto, facilitadora e promotora da descentralização. Considerando o contexto delineado para o setor saúde no Brasil, caberia investigar qual o atual sentido da desconcentração.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In the passage of life, the labyrinth of songs and corners are propitious ways for a better comprehension, perception and incorporation of learnings that emerge from our subjectiveness in a magic caught by senses. Eyesight, taste, hearing, touch and smell in communication with the world, put us in front of cultural diversities. The ludicity accumulated by experiences promote the flow of hilarious and concrete discoveries that express themselves in work and leisure demonstrations. Such reflections emerge indicators to the problematic construction centralized in the incorporation of cultural experience knowledge to the formation process and professional interventions in this rule and area. From this significant problematic, aiming to deepen studies, we favored leisure as field of investigative production in full expansion. This, for sure, was an exercise of qualification that guided us through meander of education and made us dip into studies about the corporeity. A research in which the scenery was painted and constructed with the complicity of the culture lived with shine, colors, rhythm and drummings of one of the most present cultural cycles: carnival. Recognized as a stimulant for beauty, participation, socialization, and helped us to enter in the essence of gestures and expressions of corporeity, to think, elaborate and socialize a critic-scientific knowledge which, appropriating from the rhythm of colors, of sounds, of tonalities, of senses and of meanings impregnated in the web of life. All these things seduced the researcher, making imagination flow amid ludic-creative dialogues with the imaginary of researchers creation and production in the rule and area of leisure, education and corporeity. Option that made us outline as objective to investigate and interpret how leisure teachers-researchers, from their studies, researches and interventions, locate and incorporate the knowledge from cultural experience to the formation process and intervention of professionals in this rule and in this area, emphasizing the contributions from this knowledge to fence and qualify this praxis. So, as living each cultural scenery, each epistemological contribution was feeding the production with images of the different versions of the Brazilian breedings, creating and raising expectations and new discoveries and newcomers. With the seriousness of a scientific study, we lived an xxiii academic experience with complex intensity, rigor and coherence, eliminating, step by step, the risks and limitations always present in a work of this magnitude. However, we weren t, even for one moment, alone. Our epistemic regard always maintained mediated by the principles of a methodological approach - the Etnomethodology, that while central guide provided us clues to unveil the lived world by our people-playful , in a universe of 15 members, that allowed themselves to comprehend, comment, analyze. This way, grasping the object in interactions arised and provoked by narrative interview, it was systematically dialected by (re) interpretation of images and formulations of people-playful, enriched by their beliefs, myths, conceptions and rituals inherent to knowledge from cultural experience, which each one attuned with Brazilian and international history, in a mixture of senses echoed from songs and tales. Inspired in drummings and percussions, clothing and choreographies of gestures and expressions, in mixtures produced in unit interactions in the multiplicity shown as necessary requests to the totality of life, with ludicity the rescue of the past, the conquest of present and the construction of future was the axle guide. This rich process of scientific creation made us realize that is possible qualify and empower the praxis in the rule and area of leisure incorporating the knowledge from cultural experience. What also becomes possible is the recuperation of objective revolutionaries and changing conditions of praxis itself with the view of strengthening and triggerment of vital elements in the rule and area of leisure. We also reaffirm that from this praxis emerge elements necessary to human formation in plenitude, by the appropriation of knowledge that guide the facing of challenges of a complex and plural world that valorize education, corporeity and leisure

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Comprehending social representations of users relatives of Psychosocial Care Centers (CAPS) from Natal-RN, about their participation in the activities of these services, was the purpose of this study. The research instrument used was a semi-structured interview, led to 28 relatives of users of East and West CAPS II, East and North CAPS-ad, involved in the Relative Therapeutic Group, in Relative Meeting, in the Assembly of Users, Technicians and Relatives, according to the therapeutic schedule of each health services, between August to November 2007. Data obtained in family and users identification were characterized with the aid of charts and boards in absolute and/or percentage values. The discursive material from the guide from interviews was submitted to the informational resource ALCESTE (Analyse Lexicale par Contexte d'un Ensemble of Segments of Texte), and analyzed on the basis of the Theory of Social Representations and Central Nucleus Theory. Most of the relatives were women, married, aged over 50 years, who participated for more than two years in CAPS activities, and a coexistence of more than 11 years with the user. From the classification system of ALCESTE were selected categories, identified by: Category 1, Treatment Improvements and Expectations; Category 2, Living User Before and After; Category 3, Activities Relevance, Contradictions and Suggestions; Category 4, Guidelines -- Psychopharmacology and Medicalization; Category 5, Family Participation and Activities; and Category 6, Therapeutic Conditions Thanks, Tips and Vulnerability. The social representation of the family exists in the desire for change, identifying that we need to promote change by the continuity of therapeutic activities and overcome the detected inconsistencies, targeted by strengthening and by the stability of improvements in living and health conditions of users, experienced in CAPS treatment. The central nucleus had corresponded to positive changes in health and living conditions of users, and the peripheral elements were constituted by family conducts before and during treatment, and the expectations of changes in activities, especially in workshops. Despite this family participation be considered important, it still does not meet conditions to promote the inclusion of family, under an emancipating point of view, capable of causing in subject the hope for autonomy, initiative, individual and collective growths, a closer and active involvement in therapeutic activities, in workshops and discussions

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Hard metals are the composite developed in 1923 by Karl Schröter, with wide application because high hardness, wear resistance and toughness. It is compound by a brittle phase WC and a ductile phase Co. Mechanical properties of hardmetals are strongly dependent on the microstructure of the WC Co, and additionally affected by the microstructure of WC powders before sintering. An important feature is that the toughness and the hardness increase simultaneously with the refining of WC. Therefore, development of nanostructured WC Co hardmetal has been extensively studied. There are many methods to manufacture WC-Co hard metals, including spraying conversion process, co-precipitation, displacement reaction process, mechanochemical synthesis and high energy ball milling. High energy ball milling is a simple and efficient way of manufacturing the fine powder with nanostructure. In this process, the continuous impacts on the powders promote pronounced changes and the brittle phase is refined until nanometric scale, bring into ductile matrix, and this ductile phase is deformed, re-welded and hardened. The goal of this work was investigate the effects of highenergy milling time in the micro structural changes in the WC-Co particulate composite, particularly in the refinement of the crystallite size and lattice strain. The starting powders were WC (average particle size D50 0.87 μm) supplied by Wolfram, Berglau-u. Hutten - GMBH and Co (average particle size D50 0.93 μm) supplied by H.C.Starck. Mixing 90% WC and 10% Co in planetary ball milling at 2, 10, 20, 50, 70, 100 and 150 hours, BPR 15:1, 400 rpm. The starting powders and the milled particulate composite samples were characterized by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) to identify phases and morphology. The crystallite size and lattice strain were measured by Rietveld s method. This procedure allowed obtaining more precise information about the influence of each one in the microstructure. The results show that high energy milling is efficient manufacturing process of WC-Co composite, and the milling time have great influence in the microstructure of the final particles, crushing and dispersing the finely WC nanometric order in the Co particles