82 research outputs found

    Wireless sensors and IoT platform for intelligent HVAC control

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    Energy consumption of buildings (residential and non-residential) represents approximately 40% of total world electricity consumption, with half of this energy consumed by HVAC systems. Model-Based Predictive Control (MBPC) is perhaps the technique most often proposed for HVAC control, since it offers an enormous potential for energy savings. Despite the large number of papers on this topic during the last few years, there are only a few reported applications of the use of MBPC for existing buildings, under normal occupancy conditions and, to the best of our knowledge, no commercial solution yet. A marketable solution has been recently presented by the authors, coined the IMBPC HVAC system. This paper describes the design, prototyping and validation of two components of this integrated system, the Self-Powered Wireless Sensors and the IOT platform developed. Results for the use of IMBPC in a real building under normal occupation demonstrate savings in the electricity bill while maintaining thermal comfort during the whole occupation schedule.QREN SIDT [38798]; Portuguese Foundation for Science & Technology, through IDMEC, under LAETA [ID/EMS/50022/2013

    Idade e crescimento do boca-negra, Helicolenus dactylopterus dactylopterus (Delaroche, 1809) dos Açores

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    A idade e o crescimento de boca-negra, Helicolenus dactylopterus dactylopterus (Delaroche, 1809), foram estudadas pela observação dos otólitos (sagittae) esquerdos inteiros (n = 401) obtidos de exemplares (14-47 cm de comprimento total) capturados em águas Açoreanas. Enumeraram-se os anéis opacos observados na face anti-sulcal dos otólitos. Os intervalos de idades foram 3-14 anos para machos e 3-12 anos para fêmeas. Estimaram-se e compararam-se os parâmetros da equação de crescimento de von Bertalanffy, entre sexos e entre métodos (leitura directa de otólitos, retrocálculo e análise de distribuições de frequências de comprimentos). Não se verificaram diferenças importantes. Os resultados são diferentes da literatura publicada para a região. Discutem-se as causas e implicações dos resultados obtidos.ABSTRACT: Bluemouth, Helicolenus dactylopterus dactylopterus (Delaroche, 1809), age and growth were studied by whole-view examination of left sagittae (n = 401) obtained from specimens (14-47 cm in total length) caught off the Azores. Opaque rings observed on the anti-sulcal surface of sagittae were enumerated as age estimates. Ages ranged from 3 to 14 years in males and 3 to 12 years in females. The von Bertalanffy growth equation was fitted to average length at age data, and compared between sexes and methods (direct examination of otoliths, backcalculation and length-frequency analysis). No important differences in growth between sexes were found. Results are different from published literature for the region. The causes and implications of the results are discussed

    Nanoemulsions for food applications: development and characterization

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    The application of nanotechnology to food, medical and pharmaceutical industries has received great attention from the scientific community. Driven by the increasing consumers’ demand for healthier and safer food products and the need for edible systems able to encapsulate, protect, and release functional compounds, researchers are currently focusing their efforts in nanotechnology to address issues relevant to food and nutrition. Nanoemulsion technology is particularly suited for the fabrication of encapsulating systems for functional compounds as it prevents their degradation and improves their bioavailability. This review focuses on nanoemulsions and provides an overview of the production methods, materials used (solvents, emulsifiers and functional ingredients) and of the current analytical techniques that can be used for the identification and characterization of nanoemulsions. Finally, nanotechnological applications in foods currently marketed are reported.M.A. Cerqueira (SFRH/BPD/72753/2010) is recipient of a fellowship from the Fundacao para a Ciencia e Tecnologia (FCT, Portugal)

    Visual assessment and diagnosis of a timber railway station warehouse in Foz do Tua

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    Aiming at the rehabilitation of a timber warehouse in the Tua train station for a new use, it was necessary to assess the level of conservation of the building’s elements and determine whether intervention measures were required. This work summarizes the assessment made of the timber elements by means visual inspection and non-destructive testing. The main results, obtained in the diagnostic survey, were the conservation level of the timber warehouse, the visual strength grading of the timber elements and damage maps indicating the main pathologies and its probable causes.The drawings of the Tua station warehouse (artmetro, arquitetos associados 2011) were provided by the Architecture School Study Centre of University of Minho and their reproduction is acknowledged. The support of FEDER through COMPETE and of FCT within the scope of project POCI-01-0145-FEDER-007633 are acknowledged. The financial support of COST FP1101 – Assessment, Reinforcement and Monitoring of Timber Structures is gratefully acknowledged.info:eu-repo/semantics/publishedVersio

    Erratum to Nanoemulsions for Food Applications: Development and Characterization (Food and Bioprocess Technology, (2012), 5, (854-867), 10.1007/s11947-011-0683-7)

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    Artigo completo publicado na revista "Food and Bioprocess Technology." 5:3 (2012) 854-867 e disponível no RepositóriUM em http://hdl.handle.net/1822/22397Where it reads: 2. Production of nanoemulsions 2.1. High-energy approaches • Ultrasound – when two immiscible liquids are submitted to high frequency sound waves in the presence of a surfactant, emulsion droplets are formed by cavitation. It should be read: 2. Production of nanoemulsions 2.2. High-energy approaches • Ultrasound – when two immiscible liquids are submitted to high intensity sound waves in the presence of a surfactant, emulsion droplets are formed by cavitation

    Regime alimentar de tintureira (Prionace glauca L.) em águas Açorianas

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    Analisaram-se os conteúdos estomacais de 195 Prionace glauca, capturadas nos Açores entre Outubro de 1993 e Julho de 1994. Oitenta e três indivíduos possuíam estragos vazios. Apenas 23 estômagos continham animais inteiros ou semi-digeridos (excluindo o isco) pertencentes aos peixes Capros aper, Macrorhamphosus scolopax e Lepidopus caudatus e às lulas Histioteuthis bonnellii e Taonius pavo. Setenta e cinco otólitos de peixe e 207 bicos inferiores de cefalópodes foram identificados até ao género ou espécie. Considerando todos os fragmentos encontrados nos estômagos, incluindo otólitos, bicos de cefalópodes e cristalinos, foram encontrados 1411 peixes, 4 crustáceos e 261 cefalópodes. Aproximadamente 386 peixes estavam representados apenas por cristalinos. Foi encontrada uma média de 2.4 espécies (1.8 cefalópodes e 0.6 peixes) e 15.2 indivíduos por estômago. Restos de peixes foram encontrados em 83% dos estômagos analisados contribuindo em 84.5% dos animais da dieta. Restos de cefalópodes, foram encontrados em 75.7% dos estômagos e compunham 15.5% dos animais da dieta. As estimações dos pesos de peixes e cefalópodes, sugerem que os cefalópodes são, provavelmente, o grupo mais importantes na dieta de tintureira e, que são quase exclusivamente cefalópodes de flutuabilidade neutra meso- ou batipelágicos. Ocorrem pequenos cardumes de peixes epipelágicos e alguns peixes bentónicos maiores. No total, a dieta é composta por, pelo menos, 11 espécies de peixe e 37 de cefalópodes. É apresentada a distribuição de comprimentos de bicos e otólitos. Um número de espécies de cefalópodes raramente capturadas são, também, importantes para a dieta. Não foram encontradas diferenças na dieta relacionadas com o tamanho ou sexo de Prionace glauca. Comparações com a dieta de espadarte e de cachalote da mesma região sugerem claramente a existência de selecção na predação.ABSTRACT: Stomach contents of 195 Prionace glauca caught off the Azores from October 1993 to July 1994 were studied. Eighty three had empty stomachs. Only 23 contained whole or fleshy parts of animals (other than bait) and all belonged to the fish Capros aper, Macrorhamphosus scolopax and Lepidopus caudatus and the squids Histioteuthis bonnellii and Taonius pavo. Seventy five fish otoliths and 207 cephalopod lower beaks were identified to genus or species. Considering all fragments from the stomachs, including otoliths, cephalopod beaks and eye lenses, a minimum of 1411 fish, 4 crustaceans and 261 cephalopods were represented. Approximately 386 of the fish were represented by eye lenses alone. There was a mean of 2.4 species (1.8 cephalopods and 0.6 fish) and 15.2 animals represented in each stomach. Fish remains occurred in 83.0% of the stomachs and contributed 84.5% of animals to the diet. Cephalopod remains occurred in 75.7% and contributed 15.5% of animals. Estimates of the weights of fish and cephalopods suggest that cephalopods are probably the most important in the diet and these were almost entirely meso- or bathypelagic, neutrally buoyant cephalopods. Small epipelagic shoaling fish were present with a few much larger near-bottom fish. In all, there are at least 11 species of fish and at least 37 species of cephalopod in the diet. Size distributions of beaks and otoliths are presented. A number of rarely caught species of cephalopod are important in the diet. No difference was found in diet according to the size or between male and female Prionace glauca. Comparisons with swordfish and sperm whale diets from the same region clearly suggest selection in their predation

    A dieta do espadarte (Xiphias gladius) em águas Açorianas

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    Foram recolhidos um total de 132 estômagos de espadarte durante os anos de 1992/93 em indivíduos capturados em palangre derivante perto do arquipélago dos Açores. Os conteúdos foram completamente separados em componentes que incluíam: todos os estados de digestão de peixes e cefalópodes, desde peixes completos até fragmentos de músculo, ossos e otólitos e bicos de cefalópodes. Os peixes e os ossos maiores, que podem ser identificados, pertenciam todos a Capros aper, Lepidopus caudatus, Pagellus bogaraveo, mictofideos e, o peixe que servia de isco, Trachurus picturatus. Músculo das lulas Todarodes sagittatus, Pholidoteuthis boschmai e a lula que servia de isco Illex sp. também foi encontrada. 1249 otólitos e 120 bicos (inferiores) de cefalópodes foram identificados até ao género ou espécie. Encontrou-se uma média de 3.1 espécies e 18 animais representados em cada estômago. 98.4% dos estômagos apresentavam restos de peixes que contribuíam com 93.4% dos animais na dieta. Encontraram-se cefalópodes em 37.4% dos estômagos que contribuíram com 5.8% dos animais. Estimou-se que os pesos dos cefalópodes e peixes contribuíam respectivamente com 50.5% e 49.5% dos conteúdos estomacais. Os constituintes mais importantes da dieta, determinados por depleção de % peso estimado são Ommastrephes bartrami (24.4%), Lepidopus caudatus (17.4%), Pholi-doteuthis boschmai (15.9%), Capros aper (14.9%), Beryx spp. (5.4%), Micromesistius poutassou Onychoteuthis sp. (3.9%), Moroteuthis sp. (2.7%) e Pagellus bogoraveo (2.2%). Ao todo, há mais do que 18 espécies de peixe e 22 de cefalópodes na dieta. Apresentam-se as distribuições por tamanho de otólitos e bicos. Há espécies bentónicas e mesopelágicas de águas oceânicas, costeiras e profundas. Aparecem, na dieta, algumas espécies raras e não registadas para os Açores. As dietas não variam de acordo com a dimensão do espadarte amostrado ou entre sexos. Cálculos preliminares sobre a biomassa mínima consumida pelo espadarte dos Açores apontam para um número entre 7280 a 8680 t por ano, sendo aproximadamente metade peixe e metade cefalópodes.ABSTRACT: A total of 132 stomachs were collected in 1992-93 from swordfish caught on drifting longlines near the Azores. Contents were sorted completely into components which comprised all stages of digested fish and cephalopods from complete fish to fragments of muscle, bones, otoliths and beaks of cephalopods. Fish and larger bones which could be identified all belonged to Capros aper. Lepidopus caudatus, Pagellus bogaraveo, myctophids, and the fish used as bait, Trachurus picturatus. Flesh of the squids Todarodes sagittatus, Pholidoteuthis boschmai and the squid used as bait Illex sp. was also present. 1249 otoliths and 120 cephalopod lower beaks were identified to genus or species. There was a mean of 3.1 species and 18 animals represented in each stomach. Fish remains occurred in 98.4% of the stomachs and contributed 93.4% of animals in the diet. Cephalopod remains occurred in 37.4% and contributed 5.8% of animals. Estimates of the weights of fish and cephalopods show that cephalopods provide 50.5% and fish species 49.5% of the stomach contents. The most important constituents of the diet by decreasing % estimated weight are Ommastrephes bartrami (24.4%), Lepidopus caudatus (17.4%), Pholidoteuthis boschmai (15.9%), Capros aper (14.9%), Beryx spp. (5.4%), Micromesistius poutassou (4.3%), Onychoteuthis sp. (3.9%), Moroteuthis sp. (2.7%) and Pagellus bogaraveo (2.2%). In all, there are more than 18 species of fish and 22 species of cephalopod in the diet. Size distributions of otoliths and beaks are presented. The species include bottom and midwater forms from both oceanic and near island water and depths. A number of rare species of cephalopods and species not recorded for the Azores are in the diet. Diet does not differ according to the size of swordfish sampled or between female and male swordfish. Preliminary calculations were made on the minimum biomass eaten by the swordfish off the Azores as 7280 - 8680 t per year, approximately half fish and half cephalopods

    Unravelling the behaviour of curcumin nanoemulsions during in vitro digestion: effect of the surface charge

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    Oil-in-water nanoemulsions containing curcumin were prepared through high-pressure homogenization using corn oil and three different emulsifiers: Tween 20 (non-ionic), Sodium Dodecyl Sulphate (SDS, anionic) and DodecylTrimethylAmmonium Bromide (DTAB, cationic). A human gastric simulator was used as the in vitro digestion model (in which the stomach, duodenum, jejunum and ileum steps were performed) to evaluate the impact of surface charge on the digestion of the curcumin nanoemulsions. This model allowed the simulation of continuous peristaltic movements and consequently enabled a more mechanically realistic simulation of the dynamic digestion process than simple stirred vessel models. The emulsifier charge had a significant effect on the droplet size, particle electric charge and microstructure of curcumin nanoemulsions during the simulated digestion, which consequently influenced the free fatty acid release and curcumin bioavailability. The results showed the positively charged DTAB-stabilized emulsions to be the least stable during the digestion process, exhibiting the largest increase in droplet size and eventual phase separation. This also contributed to the low bioavailability of curcumin. Conversely, emulsions stabilized with Tween 20 showed retention of emulsion structure (high surface area) and greater free fatty acid production, which could explain the increased curcumin bioavailability. The emulsifier charge influenced the lipid digestion process and the bioavailability of the bioactive compound incorporated, probably by altering the ability of bile salts and digestive enzymes to adsorb onto the emulsion surfaces, thus altering the droplet size (and consequently the surface area) due to droplet breakup or coalescence within the digestive tract. The results of this work also highlighted the importance of subjecting the emulsions to a simulated gastric environment, since changes in pH, ionic strength, gastric enzyme activity and shear will impact the emulsion properties in the small-intestine. This manuscript has provided important insights into the effect of emulsifier charge on the behaviour of nanoemulsions during in vitro digestion, which is important to determine their functional performance, aiming at the optimization of nanoemulsion-based delivery systems to protect and release bioactive lipophilic compounds.Ana C. Pinheiro and Helder Silva gratefully acknowledge the Fundacao para a Ciencia e Tecnologia (FCT, Portugal) for their fellowships (SFRH/BD/48120/2008 and SFRH/BD/81288/2011 respectively). The author Ana C. Pinheiro would also like to acknowledge the European Union, through Cost Action FA1001 and the author Manuel A. Coimbra gratefully acknowledges QOPNA (project PEst-C/QUI/UI0062/2011)

    Knee surgery complications related to biomaterials

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    Recent years have seen a growing interest in biomaterials and use of these materials in the clinical setting is increasing. Despite their advantages, they have also been cited as the source of specific complications and/or fail- ures. Problems such as screw breakage, tunnel enlargement, allergic or foreign body reactions, cyst and abscess formation, or even delayed migration of supposedly biodegradable screws/implants have been reported. This chapter aims to review the basic science and clinical experience with biomaterials currently employed in fixation devices for knee surgery. Information on the clinical implications of biodegradable screws is still limited. Surgeons tend to focus more on the emerging successes of innovations than on the complications and failures (publication bias) of older devices, making it difficult to reliably assess the incidence of such events. More- over, the complexity of possible reactions occurring in the human body cannot be reproduced under controlled laboratory conditions.Neverthe- less, surgeons and patients must be aware of both the advantages and the complications of these devices. Only in this way can informed choices be made, so that both parties are prepared to face and overcome the unde- sired complications, and the improvement of future implants can become a reality

    Influence of indirect ultrasonic vibration on the microstructure and mechanical behavior of Al-Si-Cu alloy

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    The influence of high intensity ultrasound (US) propagating through a steel mold on the microstructure and mechanical properties of die-cast AlSi9Cu3, for different levels of electric power and at different distances to the waveguide/mold interface. The influence of those parameters on the morphology of -Al and eutectic Si and on the volume of porosity were investigated and characterized. The morphological characterization revealed that the high intensity vibration not only promoted the formation of small -Al globular grains but also modify the eutectic silicon, as well as decreased the volume of porosity. Besides microstructure modification, US treatment improved the alloy mechanical properties, namely UTS and strain, which maximum values were 339 MPa and 2.9% respectively by comparison to the values obtained for castings produced without US vibration. A mechanism of eutectic Si modification based on theoretical-experimental analysis is proposedFCT - Fundação para a Ciência e Tecnologi
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