303 research outputs found

    Estolides Synthesis Catalyzed by Immobilized Lipases

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    Estolides are vegetable-oil-based lubricants obtained from oleic acid or any source of hydroxy fatty acids. In this work, the estolides synthesis from oleic acid and methyl ricinoleate (biodiesel from castor oil), using immobilized commercial lipases (Novozym 435, Lipozyme RM-IM, and Lipozyme TL-IM) in a solvent-free medium was investigated. Acid value was used to monitor the reaction progress by determining the consumption of acid present in the medium. Novozym 435 showed the best performance. Water removal improved the conversion. Novozym 435 was more active at atmospheric pressure. Novozym 435 was reused four times with conversion reaching 15% after the fourth reaction at 80°C. Estolides produced under the reaction conditions used in this work presented good properties, such as, low temperature properties as pour point (−24°C), viscosity (23.9 cSt at 40°C and 5.2 cSt at 100°C), and viscosity index (153)

    Tailoring the surface properties and flexibility of starch-based films using oil and waxes recovered from potato chips byproducts

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    Agrofood byproducts may be exploited as a source of biomolecules suitable for developing bioplastic materials. In this work, the feasibility of using starch, oil, and waxes recovered from potato chips byproducts for films production was studied. The recovered potato starch-rich fraction (RPS) contained an amylopectin/amylose ratio of 2.3, gelatinization temperatures varying from 59 to 71 °C, and a gelatinization enthalpy of 12.5 J/g, similarly to a commercial potato starch (CPS). Despite of its spherical and oval granules identical to CPS, RPS had a more amorphous structure and gave rise to low viscous suspensions, contradicting the typical B-type polymorph crystal structure and sluggish dispersions of CPS, respectively. When used for films production, RPS originated transparent films with lower roughness and wettability than CPS-based films, but with higher stretchability. In turn, when combined with RPS and CPS, oil or waxes recovered from frying residues and potato peels, respectively, allowed to develop transparent yellowish RPS- and CPS-based films with increased surface hydrophobicity, mechanical traction resistance, elasticity, and/or plasticity. Therefore, potato chips industry byproducts revealed to have thermoplastic and hydrophobic biomolecules that can be used to efficiently develop biobased plastics with improved surface properties and flexibility, opening an opportunity for their valorization.publishe

    Diet of mid-Atlantic Sowerby’s beaked whales Mesoplodon bidens

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    Copyright © 2011 Elsevier Ltd. All rights reserved.The first mid-Atlantic diet of Mesoplodon beaked whales is presented, from ten Sowerby's Mesoplodon bidens stranded in the Azores region between 2002 and 2009. This doubles the worldwide number of stomachs sampled, and reveals new feeding habits for this species. The mean number of prey items per stomach was 85±89 (range: 12–238), with fish accounting for 99.3% and cephalopods contributing less than 1% of total prey. Fish otoliths from 15 families and cephalopod lower mandibles from three families were identified, representing 22 taxa. The diet consisted mainly of small mid-water fish, the most numerous being Diaphus sp., Lampanyctus sp. and Melamphaidae species. Myctophids were present in all stranded individuals, followed by Diretmidae, Melamphaidae and Opisthoproctus soleatus, while the remaining fish species were scarce or single occurrences. Consistency of diet in four different years reveals a divergence from all previous records in continental areas, where mainly neritic and shelf-break benthopelagic fish species have been reported. Mid-Atlantic Sowerby's beaked whales' showed dietary plasticity, feeding on the most abundant mid-water groups occurring between 0 and750 m. Trophic level from prey numerical frequency was estimated at 4.4±0.46

    Enhancing the longevity and functionality of Ti-Ag dry electrodes for remote biomedical applications: a comprehensive study

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    This study aims to evaluate the lifespan of Ti-Ag dry electrodes prepared using flexible polytetrafluoroethylene (PTFE) substrates. Following previous studies, the electrodes were designed to be integrated into wearables for remote electromyography (EMG) monitoring and electrical stimulation (FES) therapy. Four types of Ti-Ag electrodes were prepared by DC magnetron sputtering, using a pure-Ti target doped with a growing number of Ag pellets. After extensive characterization of their chemical composition and (micro)structural evolution, the Ti-Ag electrodes were immersed in an artificial sweat solution (standard ISO-3160-2) at 37 °C with constant stirring. Results revealed that all the Ti-Ag electrodes maintained their integrity and functionality for 24 h. Although there was a notable increase in electrical resistivity beyond this timeframe, the acquisition and transmission of (bio)signals remained viable for electrodes with Ag/Ti ratios below 0.23. However, electrodes with higher Ag content (Ag/Ti = 0.31) became insulators after 7 days of immersion due to excessive Ag release into the sweat solution. This study concludes that higher Ag/Ti atomic ratios result in heightened corrosion processes on the electrode’s surface, consequently diminishing their lifespan despite the advantages of incorporating Ag into their composition. This research highlights the critical importance of evaluating electrode longevity, especially in remote biomedical applications like smart wearables, where electrode performance over time is crucial for reliable and sustained monitoring and stimulation.This research was funded by the European Regional Development Fund (ERDF) through the Operational Programme for Competitiveness and Internationalization (COMPETE 2020) under Portugal 2020, in the framework of the NanoStim (POCI-01-0247-FEDER-045908) and NanoID (NORTE-01-0247-FEDER-046985) Projects

    Ordered mesoporous silica materials for protein adsorption

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    Lysozyme and BSA were used, as model proteins of considerably different dimensions, in order to evaluate the influence of the distinct pore structural characteristics of three types of ordered mesoporous silica materials (MCF, SBA-15 and MCM-41) on protein adsorption. Characterisation by X ray diffraction and nitrogen adsorption at 77K revealed the typical pore structural features of each type of material. The maximum of the pore size distributions indicated that the width of the windows of MCF (2) (mesitylene/P123 of 2) was larger than the pore diameter of the unidirectional tubular pores of SBA-15. All the materials presented similar small external surface areas but high pore volumes, with that of MCF (2) being the highest. The adsorption of lysozyme at pH=8 increased in the order MCM-41<< SBA-15< MCF (2), and the uptakes were well above those of BSA at pH=5. Although BSA is not completely excluded from the mesopores of SBA-15 and MCF (2), as happens with MCM-41, the adsorption occurs to a very limited extent. The overall behaviour of these SBA-15 and MCF (2) samples was not significantly different and both revealed potential for the separation of these proteins

    Novos registros de moscas-das-frutas (Diptera: Tephritidae), hospedeiros silvestres e parasitóides (Hymenoptera: Braconidae) na Amazônia brasileira

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    Anastrepha anomala Stone was obtained from Parahancornia amapa (Huber) Ducke (Apocynaceae) fruits, and Anastrepha hastata Stone from Cheiloclinium cognatum (Miers.) (Hippocrateaceae) in the State of Amapá, Brazil. Two braconids, Doryctobracon sp. and Opius bellus Gahan, were reared from the latter fruit fly species. This is the first record of P. amapa as a fruit fly host. C. cognatum is the first host known to A. hastata. Both braconids are also the first records of parasitoids for this species.Anastrepha anomala Stone foi obtida de frutos de Parahancornia amapa (Huber) Ducke (Apocynaceae) e Anastrepha hastata Stone de Cheiloclinium cognatum (Miers.) (Hippocrateaceae) no Amapá, sendo obtidos dois braconídeos, Doryctobracon sp. e Opius bellus Gahan, dessa espécie. Este é o primeiro registro de P. amapa como hospedeiro de moscas-das-frutas. C. cognatum é o primeiro hospedeiro conhecido de A. hastata e os braconídeos são também os primeiros registros de parasitóides dessa espécie.Agência de Desenvolvimento da Amazônia and Secretaria de Estado da Ciência e Tecnologia do Amap

    Tratamento de efluente da indústria de laticínios aplicando processo oxidativo avançado (H2O2/TiO2/UV)

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    O soro do leite, um subproduto da fabricação de queijos, apresenta altas cargas de lipídios, carboidratos e proteínas, que são de difícil biodegradabilidade e apresentam riscos ao meio ambiente. São produzidos cerca de 145 milhões de toneladas por ano de soro no mundo. Por isso, devem ser tratados adequadamente antes de serem lançados nos corpos receptores. Os processos oxidativos avançados (POA’s) podem ser uma alternativa não convencional, para o tratamento desse tipo de efluente, cuja eficiência do tratamento, tem-se mostrado como uma alternativa viável. Os POA’s são processos físico-químicos que geram espécies transitórias com elevado poder oxidante, principalmente o radical hidroxila (•OH), este radical oxida uma grande variedade de compostos orgânicos em CO2, H2O e íons inorgânicos. Com base nisso, o objetivo do trabalho foi de estudar o tratamento de efluente da indústria de laticínios através de POA’s em reator tubular com lâmpada de luz negra em processo de fotocatálise heterogênea (H2O2/TiO2/UV). Para isso foi utilizado um planejamento experimental 22. Obteve-se melhor resposta na concentração de TiO2 de 1,5 g/L e 200 mM de H2O2, reduzindo-se em cerca de 34% em DQO do efluente, em 20 minutos. Obteve-se um valor final de custo igual a US 0,05/LouUS 0,05/L ou US 50/m

    Discards for Southern Hake Stock, a First Approach to Iberian Data

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    This document presents sampling levels obtained with Portuguese and Spanish Discard Sampling Programmes, both included in National Sampling Programmes, and some preliminary results for the Iberian Southern Hake discards. These programs consist on onboard-observer sampling schemes, with co-operative vessels, quasirandom selected, in the ICES Division VIIIc and IXa. The methodology used to estimate hake discards for Portugal and Spain since 2003 was based on the one proposed in the “Workshop on Discard Sampling Methodology and Raising Procedures” (PGCCDBS, Denmark, 2003). Spain presents results for the years 1994, 1997, 1999, 2000, 2003 and 2004. In the Portuguese Program, 2004 is the first year with an analysis of discard data. The number of trips sampled by the Spanish program for 2004 was 53, distributed by three trawl fleets- BACA trawl, Pair trawl and WHVO trawl. Portuguese onboard-observers sampled 40 trips distributed by Crustacean and Fish trawl fleets. The estimated percentages of discarded hake in relation to total catch were of 19,9 (C.V. = 22.6%) and 46,7 (C.V. = 72.1%) for the Spanish and Portuguese fleets respectively. The confidence interval for the Portuguese discard estimate is very large which denotes the very low precision of the obtained value. A co-operation in the analysis of this kind of data, between the two countries, could be the next step, since a standardisation of the methods would be of great importance for a realistic comparison of results obtained from both programs

    Paradoxical effects of Worrisome Thoughts Suppression: the influence of depressive mood

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    Thought suppression increases the persistence of unwanted idiosyncratic worries thoughts when individuals try to suppress them. The failure of suppression may contribute to the development and maintenance of emotional disorders. Depressive people seem particulary prone to engage in unsuccessful mental control strategies such as thought suppression. Worry has been reported to be elevated in depressed individuals and a dysphoric mood may also contribute for the failure of suppression. No studies examine, however, the suppression of worisome thoughts in individuals with depressive symptoms. To investigate the suppression effects of worrisome thoughts, 46 participants were selected according to the cut-off score of a depressive symptomatology scale and they were divided in two groups (subclinical and nonclinical group). All the individuals took part in an experimental paradigm of thought suppression. The results of the mixed factorial analysis of variance revealed an increased frequency of worrisome thoughts during the suppression phase on depending of the depressive symptoms. These findings confirm that depressive mood can reduce the success of suppression.info:eu-repo/semantics/publishedVersio

    Assets em Áreas Protegidas: Estudo de Caso em Áreas Úmidas

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    As áreas protegidas (APs) são as principais ferramentas capazes de assegurar a preservaçãodos sistemas naturais e sua respectiva biodiversidade, principalmente no caso de áreas com prioridade para conservação, como ocorre com as áreas úmidas. A implementação de APs tem potencial para gerar benefícios fundamentais para proteger paisagens icônicas, espécies ameaçadas e serviços ecossistêmicos; entretanto, essas áreas têm custos sociais e econômicos que, muitas vezes, se tornam difíceis de justificar em períodos de crescente insegurança alimentar e crise financeira. Recentemente, sugeriu-se um modelo conceitual para apoiar a gestão das APs (PA Asset Framework) que (re)define as APs como um sistema de assets biofísicos, humanos, de infraestrutura, institucionais e culturais. De acordo com esse marco, as APs podem ser geridas e planejadas para gerar diferentes formas de valores, desse modo contribuindo para aumentar sua resiliência política/social e identificar investimentos financeiros que possam auxiliar o reconhecimento e a captura de valores por distintos públicos. Neste artigo, aplicamos o PA asset framework para levantar a presença de assets em parques nacionais localizados em áreas úmidas, a partir da revisão sistemática dos planos de manejo. Nestes, identificamos os assets presentes e mais recorrentes em tais áreas. Nossos resultados mostram que o número de assets representados e reconhecidos nos planos de manejo é limitado, concentrando-se, principalmente, em algumas classes biofísicas relacionadas à conservação da biodiversidade (ex: espécies de importância para a conservação e espécies de importância econômica), de infraestrutura necessária paramanutenção das atividades de gestão (ex: funcionário permanente, infraestrutura para gestão, eletricidade e veículos) e institucionais (estratégias de planejamento e zoneamento). Por outro lado, dada a importância sociocultural das áreas úmidas em nível nacional e global, o baixo reconhecimento de assets humanos e culturais nessas áreas sugere que a inclusão desses valores nos planos de manejo pode ser benéfica para potencializar os valores associados a essas tipologias de asset. Argumentamos que o levantamento dos assets em APs, além de revelar os bens/recursos/atributos/dimensões-chave que podem estar sendo negligenciados nos planos de manejo, oferece uma abordagem inovadora para que os gestores possam elaborar estratégias de investimento a partir do reconhecimento de valores tangíveis e intangíveis das APs e dos seus assets, para além dos biofísicos
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