940 resultados para Mill setup
Resumo:
Knowledge-elicitation is a common technique used to produce rules about the operation of a plant from the knowledge that is available from human expertise. Similarly, data-mining is becoming a popular technique to extract rules from the data available from the operation of a plant. In the work reported here knowledge was required to enable the supervisory control of an aluminium hot strip mill by the determination of mill set-points. A method was developed to fuse knowledge-elicitation and data-mining to incorporate the best aspects of each technique, whilst avoiding known problems. Utilisation of the knowledge was through an expert system, which determined schedules of set-points and provided information to human operators. The results show that the method proposed in this paper was effective in producing rules for the on-line control of a complex industrial process.
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This paper describes the design, implementation and testing of an intelligent knowledge-based supervisory control (IKBSC) system for a hot rolling mill process. A novel architecture is used to integrate an expert system with an existing supervisory control system and a new optimization methodology for scheduling the soaking pits in which the material is heated prior to rolling. The resulting IKBSC system was applied to an aluminium hot rolling mill process to improve the shape quality of low-gauge plate and to optimise the use of the soaking pits to reduce energy consumption. The results from the trials demonstrate the advantages to be gained from the IKBSC system that integrates knowledge contained within data, plant and human resources with existing model-based systems. (c) 2005 Elsevier Ltd. All rights reserved.
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Six land surface models and five global hydrological models participate in a model intercomparison project (WaterMIP), which for the first time compares simulation results of these different classes of models in a consistent way. In this paper the simulation setup is described and aspects of the multi-model global terrestrial water balance are presented. All models were run at 0.5 degree spatial resolution for the global land areas for a 15-year period (1985-1999) using a newly-developed global meteorological dataset. Simulated global terrestrial evapotranspiration, excluding Greenland and Antarctica, ranges from 415 to 586 mm year-1 (60,000 to 85,000 km3 year-1) and simulated runoff ranges from 290 to 457 mm year-1 (42,000 to 66,000 km3 year-1). Both the mean and median runoff fractions for the land surface models are lower than those of the global hydrological models, although the range is wider. Significant simulation differences between land surface and global hydrological models are found to be caused by the snow scheme employed. The physically-based energy balance approach used by land surface models generally results in lower snow water equivalent values than the conceptual degree-day approach used by global hydrological models. Some differences in simulated runoff and evapotranspiration are explained by model parameterizations, although the processes included and parameterizations used are not distinct to either land surface models or global hydrological models. The results show that differences between model are major sources of uncertainty. Climate change impact studies thus need to use not only multiple climate models, but also some other measure of uncertainty, (e.g. multiple impact models).
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This article surveys the fiercely contested posthumous assessments of John Stuart Mill in the newspaper and periodical press, in the months following his death in May 1873, and elicits the broader intellectual context. Judgements made in the immediate wake of Mill's death influence biographers and historians to this day and provide an illuminating aperture into the politics and shifting ideological forces of the period. The article considers how Mill's failure to control his posthumous reputation demonstrates both the inextricable intertwining of politics and character in the 1870s, and the difficulties his allies faced. In particular, it shows the sharp division between Mill's middle and working class admirers; the use of James Mill's name as a rebuke to his son; the redefinition of Malthusianism in the 1870s; and how publication of Mill's Autobiography damaged his reputation. Finally, the article considers the relative absence of both theological and Darwinian critiques of Mill.
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This short article explores the life and work of Ethel Carnie Holdsworth, the first working-class woman in Britain to publish full-length novels. It assesses her politics and her literacy legacy and is part of the Women's History Network's series, 'Reclaiming Women's Histories'.
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This essay aims to demonstrate how Dickens’s search for ‘truth’ (and his understanding of what that abstraction consists of) entered into and emerged from one of the key philosophical discussions of the early nineteenth century: namely whether moral knowledge is the sum of one’s experiences or whether there are such things as a priori or ‘natural’ principles of ethics that transcend human practice.
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The objective of this article is to study the problem of pedestrian classification across different light spectrum domains (visible and far-infrared (FIR)) and modalities (intensity, depth and motion). In recent years, there has been a number of approaches for classifying and detecting pedestrians in both FIR and visible images, but the methods are difficult to compare, because either the datasets are not publicly available or they do not offer a comparison between the two domains. Our two primary contributions are the following: (1) we propose a public dataset, named RIFIR , containing both FIR and visible images collected in an urban environment from a moving vehicle during daytime; and (2) we compare the state-of-the-art features in a multi-modality setup: intensity, depth and flow, in far-infrared over visible domains. The experiments show that features families, intensity self-similarity (ISS), local binary patterns (LBP), local gradient patterns (LGP) and histogram of oriented gradients (HOG), computed from FIR and visible domains are highly complementary, but their relative performance varies across different modalities. In our experiments, the FIR domain has proven superior to the visible one for the task of pedestrian classification, but the overall best results are obtained by a multi-domain multi-modality multi-feature fusion.
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Electron transport parameters are important in several areas ranging from particle detectors to plasma-assisted processing reactors. Nevertheless, especially at high fields strengths and for complex gases, relatively few data are published. A dedicated setup has been developed to measure the electron drift velocity and the first Townsend coefficient in parallel plate geometry. An RPC-like cell has been adopted to reach high field strengths without the risk of destructive sparks. The validation data obtained with pure Nitrogen will be presented and compared to a selection of the available literature and to calculations performed with Magboltz 2 version 8.6. The new data collected in pure Isobutane will then be discussed. This is the first time the electron drift velocity in pure Isobutane is measured well into the saturation region. Good agreement is found with expectations from Magboltz. (C) 2009 Elsevier B.V. All rights reserved.
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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.
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Esta dissertação aborda a implantação de sistemática para Troca Rápida de Ferramentas (TRF), através de proposta de implantação elaborada pela revisão da literatura e comprovação prática da sistemática realizada através de estudo de caso aplicado na indústria moveleira. A Troca Rápida de Ferramentas fornece condições para a redução do tempo de preparação dos equipamentos, possibilitando uma estratégia de produção de lotes de tamanho reduzido. A TRF está associada a uma série de ferramentas de melhoria, com ênfase em técnicas de formação de equipes de trabalho e utilização da capacidade criativa destas equipes na melhoria dos métodos existentes. A presente dissertação apresenta revisão da literatura abordando dois assuntos principais: (i) elaboração de uma sistemática de TRF, e (ii) implantação da sistemática em processos da indústria moveleira. A implantação da sistemática ocorre através das seguintes etapas: (i) definição do projeto, (ii) planejamento da implantação, (iii) treinamento em troca rápida de ferramentas, (iv) implantação efetiva, e (v) acompanhamento e consolidação. Por fim, através dos dados coletados ao longo da implantação, são apresentados resultados comparativos entre situações antes e depois da implantação da sistemática proposta na dissertação. Também são apresentadas conclusões finais e recomendações para trabalhos futuros.
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A Annona cherimola é um fruto exótico, com um sabor agradável. Este fruto tem um elevado potencial comercial, mas apresenta um tempo médio de vida curto devido ao seu rápido amadurecimento. Por esta razão é necessário conhecer melhor o processo de amadurecimento deste fruto. Na Região Autónoma da Madeira a cultura da anoneira é muito importante em termos comerciais. O processo de amadurecimento leva a diversas modificações bioquímicas e fisiológicas. Existem várias enzimas e substâncias que integram este processo. Neste trabalho iremos estudar os genes das enzimas malato desidrogenase e H+ ATPase vacuolar que estão envolvidos no processo de amadurecimento dos frutos. Utilizando as técnicas de RACE e sequenciação foi possível determinar a sequência nucleotídica do cDNA destes genes. O cDNA da malato desidrogenase é composto por 1364 nucleótidos, contendo uma zona 5’ UTR com 84 nucleótidos, uma zona 3’ UTR com 284 nucleótidos e um sinal de poliadenilação com a sequência AATAAA. A ORF apresenta 996 nucleótidos, codificando uma proteína com 332 aminoácidos. Para a H+ ATPase vacuolar foi amplificado o cDNA da subunidade C do domínio V1. Esta apresenta 799 nucleótidos, dos quais 36 são da 5’ UTR, 266 da 3’ UTR e 498 da ORF. A ORF codifica uma proteína com 166 aminoácidos.
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The analysis of volatile compounds in Funchal, Madeira, Mateus and Perry Vidal cultivars of Annona cherimola Mill. (cherimoya) was carried out by headspace solid-phase microextraction (HS-SPME) combined with gas chromatography–quadrupole mass spectrometry detection (GC–qMSD). HS-SPME technique was optimized in terms of fibre selection, extraction time, extraction temperature and sample amount to reach the best extraction efficiency. The best result was obtained with 2 g of sample, using a divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fibre for 30 min at 30 °C under constant magnetic stirring (800 rpm). After optimization of the extraction methodology, all the cherimoya samples were analysed with the best conditions that allowed to identify about 60 volatile compounds. The major compounds identified in the four cherimoya cultivars were methyl butanoate, butyl butanoate, 3-methylbutyl butanoate, 3-methylbutyl 3-methylbutanoate and 5-hydroxymethyl-2-furfural. These compounds represent 69.08 ± 5.22%, 56.56 ± 15.36%, 56.69 ± 9.28% and 71.82 ± 1.29% of the total volatiles for Funchal, Madeira, Mateus and Perry Vidal cultivars, respectively. This study showed that each cherimoya cultivars have 40 common compounds, corresponding to different chemical families, namely terpenes, esters, alcohols, fatty acids and carbonyl compounds and using PCA, the volatile composition in terms of average peak areas, provided a suitable tool to differentiate among the cherimoya cultivars.
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Agricultural and agro-industrial residues are often considered both an environmental and an economical problem. Therefore, a paradigm shift is needed, assuming residues as biorefinery feedstocks. In this work cherimoya (Annona cherimola Mill.) seeds, which are lipid-rich (ca. 30%) and have a significant lignocellulosic fraction, were used as an example of a residue without any current valorization. Firstly, the lipid fraction was obtained by solvent extraction. Extraction yield varied from 13% to 28%, according to the extraction method and time, and solvent purity. This oil was converted into biodiesel (by base-catalyzed transesterification), yielding 76 g FAME/100 g oil. The obtained biodiesel is likely to be incorporated in the commercial chain, according to the EN14214 standard. The remaining lignocellulosic fraction was subjected to two alternative fractionation processes for the selective recovery of hemicellulose, aiming different products. Empirical mathematical models were developed for both processes, aiming future scale-up. Autohydrolysis rendered essentially oligosaccharides (10 gL-1) with properties indicating potential food/feed/pharmacological applications. The remaining solid was enzymatically saccharified, reaching a saccharification yield of 83%. The hydrolyzate obtained by dilute acid hydrolysis contained mostly monosaccharides, mainly xylose (26 gL-1), glucose (10 gL-1) and arabinose (3 gL-1), and had low content of microbial growth inhibitors. This hydrolyzate has proven to be appropriate to be used as culture media for exopolisaccharide production, using bacteria or microbial consortia. The maximum conversion of monosaccharides into xanthan gum was 0.87 g/g and kefiran maximum productivity was 0.07 g.(Lh)-1. This work shows the technical feasibility of using cherimoya seeds, and materials as such, as potential feedstocks, opening new perspectives for upgrading them in the biorefinery framework.
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A hidroponia é uma técnica poderosa na utilização eficiente dos recursos agrícolas, pois permite um ganho quer na produtividade, quer na qualidade do fruto. Atualmente os sistemas hidropónicos utilizados em plantas de médio porte não são os mais adequados, sendo esta uma área a explorar. Neste trabalho criou-se um novo sistema hidropónico (Deep Large Flow Technique- DLFT) para aplicação a plantas de médio porte e avaliou-se o seu impacto no crescimento, produtividade, biomassa e qualidade do tomate cereja (Solanum lycopersicum var. Moscatel RZ). O sistema de cultivo tradicional (solo) e semi-hidropónico (suporte com fibra de coco) serviram como base de comparação. Observou-se que após 31 dias as plantas cultivadas no novo sistema hidropónico obtiveram um crescimento acentuado, apresentando 3x mais frutos. Em termos de produtividade, os sistemas hidropónicos foram iguais, sendo o sistema tradicional 4x inferior. O total de biomassa foi significativamente maior no novo sistema hidropónico, com mais 20% e 88% que o sistema semi-hidropónico e tradicional, respetivamente. As plantas produzidas no sistema DLFT apresentaram frutos com qualidade superior, com um rácio de monossacarídeos/acidez de 6,6 mg/g. O conteúdo total de ácidos gordos nos frutos cultivados com este sistema foi 39% e 44% superior aos do semihidropónico e do tradicional. Contrariamente, o conteúdo de flavonóides foi inferior nos frutos cultivados com o novo sistema hidropónico, tendo os frutos do sistema tradicional e do sistema semi-hidropónico 40% e 10% maior teor desta família de compostos. Os resultados obtidos neste estudo demonstram que a utilização do novo sistema hidropónico na produção de plantas de médio porte, aumenta o crescimento, a acumulação de biomassa e a qualidade do fruto. Assim, permite ao produtor reduzir os custos, rentabilizar a produção (menor tempo de produção), valorizar a biomassa da planta e aumentar a qualidade do produto. Também, através dos teores de carotenóides, ácidos gordos e polifenóis poderá inferir-se que ocorreu um menor impato dos stressses abióticos subjacentes aos sistemas nas plantas produzidas pelo sistema DLFT.