169 research outputs found
Laitiers d’aciérie portugaise : un nouveau géomatériau
The engineering properties of Portuguese processed steel slags (ISACs) are tested to evaluate the appropriateness of their use in
transportation infrastructures and geotechnical works. The laboratory results are compared with values specified in the Portuguese standards for natural aggregates and with values found for natural aggregates of various geological origins. The elastic modulus is carefully evaluated in order to compare the two ISACs with two standard base coarse materials (granite aggregate 0/31.5mm and limestone aggregate 0/19mm). All laboratory results show that the national processed steel slags could be used in geotechnical works, and particularly in transportation infrastructures. The two ISACs demonstrated better mechanical properties than the standard, unbound, granular base, coarse materials.Dans cet article sont présentés les résultats d'essai en laboratoire pour évaluer les propriétés des agrégats laitiers d’aciérie Portugaises (ISAC), dans le but de leur utilisation dans des infrastructures de transport et des travaux géotechniques. Les résultats sont comparés
aux valeurs indiquées dans les normes portugaises pour les agrégats traditionnels et avec des valeurs trouvées pour les agrégats
naturels de différentes origines géologiques. Une attention particulière est faite en termes du module élastique, comparant les deux
ISACs, à deux matériaux standards de sous-couches de chaussées (agrégat 0/31.5mm de granite et agrégat 0/19mm de calcaire). Tous
les résultats de laboratoire montrent que les laitiers d’aciérie Portugaises pourraient être employés dans les travaux géotechniques, et
en particulier dans les infrastructures de transport. On l'a également expérimentalement observé que les deux ISACs ont de meilleures
propriétés mécaniques que les matériaux non traités des sous-couches des chaussées.FEDERFundação para a Ciência e a Tecnologia (FCT) - POCI/ECM/56952/2004POCI 201
Processed Portuguese steel slag: a new geomaterial
The management strategy for waste, in which the prevention of its produc-
tion is not yet feasible, should lead to the prioritization of the exploitation of its performance
potential, especially through re-use solutions. On this basis, a Research and Development
Project is under way in Portugal, which is intended to re-use the processed steel slags pro-
duced in the two Portuguese Companies. In this paper are presented the results obtained
by laboratory performance-related tests for geometrical, physical and mechanical properties
for the two Portuguese processed steel slags, named Inert Steel Aggregates for Construction
(ISAC). A special emphasis is made in terms of elastic modulus, comparing the two ISACs,
with two standard base course materials (granite and limestone aggregates). The laboratory
results show that the ISACs could be used in transportation infrastructures. It was also exper-
imentally observed that the two ISACs have better mechanical properties than the standard
unbound granular base course materials.University of Illinois at Urbana-Champaig, Illinois Center for Transportation, Center of Excellence for Airport Pavement Research, University of Illinois Railroad Engineering Program, Illinois Department of Transportation, U.S. Department of Transportation, Federal Aviation Administration, Association of American Railroads, Transportation Research Board, American Society of Civil Engineer
Charging electric vehicles from photovoltaic generation with intermediate energy storage
Trabalho apresentado em 6th International Conference on Clean Electrical Power Renewable Energy Resources Impact (ICCEP17), 27-29 June 2017, Santa Margherita, Liguria, Italy.N/
Use of non traditional materials in geotechnical works – valorisation of nacional steel slags
Para avaliar a viabilidade de utilização dos ASIC (Agregado Siderúrgico Inerte para Construção) produzidos pela Siderurgia Nacional, em obras geotécnicas, estudam-se em laboratório as suas propriedades mineralógicas, quÃmicas, geométricas, fÃsicas e mecânicas. Neste trabalho apresentam-se os resultados obtidos para as propriedades mecânicas designadamente, a rigidez estudada através de um equipamento triaxial de precisão. Os resultados são comparados com os obtidos em materiais especificados para as camadas de base dos pavimentos, quer em Portugal, quer em França (agregados granÃtico 0/31,5 e calcário 0/19, respectivamente). Da comparação dos resultados conclui-se que os ASIC apresentam propriedades mecânicas superiores à s dos agregados naturais. Estes resultados enfatizam que os ASIC nacionais podem ser utilizados em obras geotécnicas, muito particularmente nas infra-estruturas de transporte.To evaluate the re-use of ASIC (Inert Steel Aggregate for Construction) produced by Siderurgia Nacional in geotechnical constructions viability, a huge laboratory experimental programme was implemented to study the mineralogical, chemical, geometrical, physical and mechanical properties. In this paper are presented the results obtained by laboratory performance-related tests for mechanical properties, namely the stiffness, studied by means of precision triaxial tests. The results obtained for the two steel slags, were compared with a standard base course materials used at Portugal and at France (granite 0/31,5 and limestone aggregate 0/19, respectively). The results obtained show that ASIC have better mechanical properties than a standard base course materials. These results emphasize that the ASIC produced at Portugal could be used in geotechnical works, and particularly in transportation infrastructures.Universidade de Coimbra. Faculdade de Ciências e Tecnologia (FCT-UC)Fundação para a Ciência e a Tecnologia (FCT) - (POCI/ECM/56952/2004)Siderurgia Nacional (SN
Laboratory and field leaching tests for predicting the environmental impact of Portuguese steel slag
The use of waste in the construction of Portuguese public works is feasible if there are no risks
for the environment. The materials that meet these requirements in Portugal are those admissible for landfills
of inert waste, their classification being done on the basis of the comparison of the leaching values obtained
in standard laboratory leach tests with the leaching limit values established in the Portuguese legislation.
This paper addresses the results of the leaching tests performed in laboratory and in the field with materials
coming from electrical arc furnace steel slag produced in the Portuguese Iron and Steel Company
Propriedades do ASIC da siderurgia nacional e possibilidades da sua utilização em obra : uma perspectiva geomecânica
Para avaliar a viabilidade de utilização dos ASIC (Agregado Siderúrgico Inerte para Construção) produzidos pela Siderurgia Nacional, em obras geotécnicas, estudam-se em laboratório as suas propriedades mineralógicas, quÃmicas, geométricas, fÃsicas e mecânicas. Neste trabalho apresentam-se os resultados obtidos para as propriedades fÃsicas e mecânicas, em particular a rigidez estudada através de um equipamento triaxial de precisão. Os resultados são comparados com os obtidos em materiais especificados para as camadas de base dos pavimentos, quer em Portugal, quer em França (agregados granÃtico 0/31,5 e calcário 0/19, respectivamente). Da comparação dos resultados conclui-se que os ASIC apresentam propriedades mecânicas superiores à s dos agregados naturais. Estes resultados enfatizam que os ASIC nacionais podem ser utilizados nas infra-estruturas de transporte
Behavioral Sciences in the Optimization of Pharmacological and Non-Pharmacological Therapy for Type 2 Diabetes
Type 2 diabetes mellitus is one of the main chronic diseases worldwide, with a significant impact on public health. Behavioral changes are an important step in disease prevention and management, so the way in which individuals adapt their lifestyle to new circumstances will undoubtedly be a predictor of the success of the treatments instituted, contributing to a reduction in the morbidity and mortality that may be associated with them. It is essential to prepare and educate all diabetic patients on the importance of changing behavioral patterns in relation to the disease, with health professionals assuming an extremely important role in this area, both from a pharmacological and non-pharmacological point of view, and also ensuring the monitoring of the progress of these measures. Diabetes is a chronic disease that requires a high self-management capacity on the part of patients in order to achieve success in treating the disease, and non-adherence to therapy or non-compliance with the previously defined plan, together with an erratic lifestyle, will contribute to failure in controlling the disease. The lower adherence to pharmacological and non-pharmacological treatment in diabetes is mainly correlated to socio-economic aspects, lower health literacy, the side effects associated with the use of antidiabetic therapy or even the concomitant use of several drugs. This article consists of a narrative review that aims to synthesize the findings published in the literature, retrieved by searching databases, manuals, previously published scientific articles and official texts, following the methodology of the Scale for Assessment of Narrative Review Articles (SANRA). We aim to address the importance of behavioral sciences in the treatment of diabetes, in order to assess behavior factors and barriers for behavior changes that have an impact on the therapeutic and non-therapeutic optimization in patients with type 2 diabetes mellitus control
Efeito de diferentes viveiros de origem e volumes de vaso na produtividade e colapso de plantas de framboesa, cultivar Sapphire
Mestrado em Engenharia Agronómica. Universidade de Lisboa, Instituto Superior de AgronomiaEm Portugal, a tecnologia de produção de Rubus idaeus L. em lançamentos de segundo ano, armazenados em frio, permite aos produtores serem competitivos no mercado mundial. Contudo, nos campos de produção de framboesa, surgem colapsos das plantas, associados a erros na execução das técnicas de produção de framboesa em viveiro, levando a quebras de produtividade e à morte das plantas. Realizaram-se três ensaios experimentais, na The Summer Berry Company, em Odemira, com o objetivo de estudar a influência de vários fatores que poderão estar na origem do colapso de plantas de framboesa da cultivar Sapphire. No ensaio 1 estudou-se a influência da origem do viveiro de propagação (Holanda – AD, BS, TY e Reino Unido – KS) e da data de saÃda da câmara de frio para o campo (8/jul, 23/jul e 12/ago de 2020) na produtividade e no colapso das plantas. No ensaio 2 estudou-se a influência do volume de vaso utilizado durante o crescimento vegetativo dos lançamentos de framboesa no primeiro ano (1,8 e 4,7 L) e da data de saÃda da câmara de frio para o campo (mesmas datas do ensaio 1) na produtividade e no colapso das plantas. No ensaio 3 estudou-se o efeito da presença/ausência de Phytophthora spp. no sistema radicular, relacionando-se este com a quantidade de reservas radiculares de amido em diferentes plantas (Colapsada, A colapsar e Não colapsada). Os resultados indicaram que o viveiro que originou plantas mais produtivas foi o KS e que lançamentos que crescem e se desenvolvem em vasos de 4,7 L são mais produtivos e colapsam menos que lançamentos de vasos de 1,8 L. Das três datas em estudo, a melhor data para a instalação dos lançamentos destinados à produção de framboesa em Portugal, foi 22 de julho, visto que se verificaram altas produtividades e aborto floral e frutÃfero mais reduzido. A presença de Phytophthora spp. e o teor reduzido de amido nas raÃzes contribuÃram para o colapso dos lançamentos. No entanto, devem ter-se em conta outros fatores que induzem stress aos lançamentos na sua fase produtiva, como as temperaturas elevadas no verão (35 a 40 ºC) durante o ciclo de produção, o excesso de horas de frio no perÃodo de conservação das long-canes em câmaras frigorÃficas (mais de 1000 h) e as condições de crescimento e desenvolvimento dos lançamentos no viveiro (densidade de lançamentos por metro linear, volume de vaso, rega, adubação, etc).In Portugal, the production technology of Rubus idaeus L. long-canes allows growers to be competitive in world market. However, in raspberry production fields, plant collapses occur, associated with raspberry production techniques in nurseries, leading to productivity losses and plant death. Three experimental assays were carried out at Portuguese Southwest coast in order to study the influence of several factors that can be on origin of plants collapse in cultivar ‘Sapphire’. In assay 1, the influence of origin propagation nursery (Holland – AD, BS, TY and United Kingdom - KS) and the exit date of plants from the cold storage to the field (07 July, 23 July and 12 August 2020) in yield and plants collapse was studied. In assay 2, the influence of pot volume used during the vegetative growth of raspberry canes on the first year (1.8 and 4.7 L) and the exit date of canes from cold storage to field (same dates as assay 1) in yield and plants collapse was assessed. In assay 3, the presence/absence of Phytophthora spp. in root system and the amount of root starch reserves related with the plants physiological condition (collapsed, collapsing and non-collapsed) was studied. The results showed that the most productive nursery is KS and canes that grow and develop in 4.7 L pots are more productive and collapse less than canes in 1.8 L pots. The best date for canes installation on field to produce raspberries in Portugal was July 22, since there were high yields and reduced flower and fruit abortion. The presence of Phytophthora spp. and low starch content in roots contributed to canes collapse, however other factors that induce stress in canes during the production cycle must be taken into account, such as the high temperatures in summer (35 to 40 ºC), the excess of cooling hours in long-canes storage (more than 1000 h) and the conditions of cane growth and development in nurseries (cane density, pot volume, irrigation, fertilization, etc).N/
Avaliação do crescimento de suÃnos de raça alentejana submetidos a acabamento intensivo até elevado peso de abate
Dissertação apresentada para a obtenção do grau de Mestre na área de Produção e Tecnologia Animal, na Escola Superior Agrária de SantarémA raça Alentejana é uma raça suÃna autóctone, com solar na região do Alentejo, associada desde sempre a sistemas de produção extensivos, onde esta população é explorada em harmonia com as condições do meio, convertendo de forma eficiente os frutos do montado, lande e bolota, em carne e gordura. No entanto, a montanheira é um recurso limitado e os sistemas extensivos têm vindo a ser complementados por sistemas semi-extensivos ou até mesmo por alguns sistemas semi-intensivos, embora os animais continuem a fazer o acabamento nos montados.
O presente estudo teve como objetivo avaliar o desempenho produtivo de suÃnos castrados de raça Alentejana, sujeitos a engorda intensiva, até um peso elevado de abate, no que concerne ao seu crescimento e Ãndice de conversão, bem como a deposição de gordura e músculo ao longo do tempo.
Avaliou-se o desempenho produtivo, bem como a deposição de gordura e espessura do músculo, em 30 porcos castrados de raça Alentejana, ao longo do crescimento intensivo dos 50 aos 160 kg de peso vivo. Procedeu-se a pesagens regulares dos animais e ao controlo individual e diário da ingestão de alimento, à medição da espessura da gordura subcutânea dorsal, da espessura da gordura subcutânea lombar e da espessura do músculo Longissimus dorsi, quando os animais atingiram os pesos vivos aproximados de 60, 90, 120 e 160 kg.
O ganho médio diário dos animais foi aceitável (831 ± 83 g), mas o Ãndice de conversão alimentar elevado (4,98 ± 0,44). Observou-se uma grande acumulação de gordura subcutânea dorsal e lombar (GD5 de 5,77 ± 0,72 cm e GL5 de 5,10 ± 0,75 cm), e um aumento relativo da espessura do músculo, com o aumento do peso do animal (60 kg de PV, 2,49 ± 0,41 cm e 160 kg de PV, 5,53 ± 0,66 cm).
Verificou-se que, com algum grau de fiabilidade, consegue-se predizer o Ãndice de conversão alimentar com base no ganho médio diário dos animais, pela equação IC = 9,16641 - 0,005033 x GMD (R2 =0,873).Relativamente à s correlações entre as variáveis em estudo, o ganho médio diário apresentou a menor correlação com o Ãndice de conversão alimentar (-0,93; p<0,05). Também a correlação entre a ingestão alimentar e o ganho de peso não foi elevada (0,41; p<0,05). As espessuras da gordura subcutânea (GD e GL), apresentaram uma forte correlação com a ingestão alimentar e com o Ãndice de conversão alimentar, refletindo a elevada capacidade adipogénica desta raça suÃna.The Alentejano pig breed is an autochthonous swine breed, typical from Alentejo’s region, and has always been associated with extensive production systems, where this population is bred in harmony with the environment, efficiently converting the fruits of the Portuguese Montado, acorn, in meat and fat. However, the production of acorn is a limited resource and this is why extensive systems have been complemented by semi-extensive systems or even by some semi-intensive systems, although the animals continue to do their finishing on the Portuguese Montado.
The aim of this study was to evaluate the performance of castrated pigs of the Alentejano pig breed, subject to intensive fattening, until they reach a high slaughter weight, as well as their growth and conversion index and the deposition of fat and muscle along of time.
During this study 30 castrated Alentejano pigs were evaluated for their performance, as well as fat deposition and muscle thickness, during intensive growth from 50 to 160 kg live weight. Each animal was weight, had its daily feed-intake controled, measured the dorsal subcutaneous fat thickness, lumbar subcutaneous fat thickness, and thickness of Longissimus dorsi muscle were performed when the animals reached the approximate live weight of 60, 90, 120 and 160 kg.
Even though there was an acceptable average daily gain (831 ± 83 g) a high feed conversion index was obtained (4.98 ± 0.44). Throughout this study, there was a high deposition of dorsal and lumbar subcutaneous fat (GD5 of 5.77 ± 0.72 cm and GL5 5.10 ± 0.75 cm) and there was a relative increase in muscle thickness with increasing animal weight (60 kg of PV, 2.49 ± 0.41 cm and 160 kg of PV, 5.53 ± 0.66 cm).
It was also shown that, with some reliability, it is possible to predict the feed conversion index based on the average daily gain of the animals from the following equation FCI = 9,16641 - 0,005033 x ADG (R2 =0,873).
Regarding the correlations between the variables under study, the average daily gain presents the lowest correlation with the feed conversion index. (-0.93; p <0.05). If on one hand, the correlation between dietary intake and weight gain was not high (0.41; p <0.05), on the other, the subcutaneous fat thickness (GD e GL), food intake and feed conversion index have shown a strong correlation, reflecting the high adipogenic capacity of this swine breed.info:eu-repo/semantics/publishedVersio
Prototype of a zero-field-cooled YBCO bearing with continuous ring permanent magnets
Based on the levitating design of the Zero-Field-Cooled (ZFC) Maglev previously developed, a novel horizontal ZFC superconductor magnetic bearing (SMB) is currently being developed. However, simulations have shown that its stator and rotor made of YBCO bulks and NdFeB permanent magnets (PM), respectively, present significant magnetic discontinuities. These produce asymmetries on the bearing rotation and several stable and unstable position angles that prevent the SMB from rotating smoothly, leading to a step motor like sort of rotation. Those drawbacks are now avoided by using ring shape PMs, leading not only to a smooth rotation of the SMB but also increasing its stability. New three-dimensional finite element method simulations and a set of experimental tests with the new SMB show in this paper the viability and increased performance when ring shape PMs are used. Finally, experimental results using the prototype also show that the model fits very well with the laboratory test results
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