20 research outputs found

    One step forward towards the development of eco-friendly antifouling coatings: Immobilization of a sulfated marine-inspired compound

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    Marine biofouling represents a global economic and ecological challenge and few eco-friendly antifouling agents are available. The aim of this work was to establish the proof of concept that a recently synthesized nature-inspired compound (gallic acid persulfate, GAP) can act as an eco-friendly and effective antifoulant when immobilized in coatings through a non-release strategy, promoting a long-lasting antifouling effect. The synthesis of GAP was optimized to provide quantitative yields. GAP water solubility was assessed, showing values higher than 1000 mg/mL. GAP was found to be stable in sterilized natural seawater with a half-life (DT50) of 7 months. GAP was immobilized into several commercial coatings, exhibiting high compatibility with different polymeric matrices. Leaching assays of polydimethylsiloxane and polyurethane-based marine coatings containing GAP confirmed that the chemical immobilization of GAP was successful, since releases up to fivefold lower than the conventional releasing systems of polyurethane-based marine coatings were observed. Furthermore, coatings containing immobilized GAP exhibited the most auspicious anti-settlement effect against Mytilus galloprovincialis larvae for the maximum exposure period (40 h) in laboratory trials. Overall, GAP promises to be an agent capable of improving the antifouling activity of several commercial marine coatings with desirable environmental properties.This research was funded by national funds through the Foundation for Science and Technology (FCT) within the scope of research unit grants to CIIMAR (UIDB/04423/2020 and UIDP/04423/2020), to BioISI (UIDB/04046/2020 and UIDP/04046/2020) and under the project PTDC/AAG-TEC/0739/2014 (reference POCI-01-0145-FEDER-016793) supported through national funds provided by FCT and the European Regional Development Fund (ERDF) via the Programa Operacional Factores de Competitividade (POFC/COMPETE) programme and the Reforçar a Investigação, o Desenvolvimento Tecnológico e a Inovação (RIDTI; project 9471)

    Low-Cost Interrogation System for Long-Period Fiber Gratings Applied to Remote Sensing

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    We present a portable and low-cost system for interrogation of long-period fiber gratings (LPFGs) costing around a 30th of the price of a typical setup using an optical spectrum analyzer and a broadband light source. The unit is capable of performing real-time monitoring or as a stand-alone data-logger. The proposed technique uses three thermally modulated fiber-coupled laser diodes, sweeping a few nanometers around their central wavelength. The light signal is then modulated by the LPFG and its intensity is acquired by a single photo-detector. Through curve-fitting algorithms the sensor transmission spectrum is reconstructed. Testing and validation were accomplished by inducing variations in the spectral features of an LPFG through changes either in external air temperature from 22 to 425 °C or in refractive index (RI) of the surrounding medium from 1.3000 to 1.4240. A dynamic resolution between 3.5 and 1.9 °C was achieved, in temperatures from 125 to 325 °C. In RI measurements, maximum wavelength and optical power deviations of 2.75 nm and 2.86 dB, respectively, were obtained in the range from 1530 to 1570 nm. The worse RI resolution obtained was 3.47 × 10 − 3 . The interrogation platform was then applied in the detection of iron corrosion, expressing wavelength peak values within 1.12 nm from the real value in the region between 1530 and 1570 nm

    Indução e desenvolvimento de calos e embriões somáticos em mamoeiro

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    Este trabalho teve por objetivo estabelecer um protocolo para a indução e desenvolvimento de calos e embriões somáticos em mamoeiro (Carica papaya L. cv. Tainung n.1). Foram utilizados quatro tipos de explantes (hipocótilo com folhas cotiledonares, hipocótilo, folhas cotiledonares e epicótilo) e duas condições de cultivo (escuro e 16 horas de luz). A indução e o desenvolvimento de calos foram avaliados nos meios de cultura ½MS2, ½MS10 e HMH e a indução e o desenvolvimento de embriões somáticos nos meios ½MS e HMH1. O cultivo de explantes de hipocótilo com folhas cotiledonares em meio de cultura ½MS10, por 20 dias, sob condições de escuro, foi o mais adequado para a indução (100%) e o crescimento de calos friáveis embriogênicos. O cultivo desses calos em meio ½MS, por duas subculturas de 30 dias, sob condições de escuro, foi o mais adequado para a indução (60%) e o desenvolvimento de embriões somáticos. O tipo de explante, meios de cultura e condições de cultivo foram definidos para a embriogênese somática em mamoeiro.<br>In order to establish a protocol for induction and development of callus and somatic embryos of papaya (Carica papaya L. cv. Tainung n.1) four explant types (hypocotyl with cotiledonary leaves, hypocotyl, cotiledonary leaves and epycotyl) and two light conditions (dark and 16 h photoperiod) were used. Callus induction and development were evaluated in ½MS2, ½MS10 and HMH media, and somatic embryo induction and development in ½MS and HMH1 media. In vitro culture of hypocotyl with cotiledonary leaves in ½MS10 medium, under dark condition for 20 days, was suitable for induction (100%) and growth of embryogenic friable callus. The culture of these callus in ½MS medium, under dark condition for two subcultures of 30 days, was suitable for induction (60%) and development of papaya somatic embryos. The explant type, culture media and culture conditions were defined for papaya somatic embryogenesis

    Composição centesimal e lipídica da carne de ovinos do nordeste brasileiro Proximate analysis and lipidic composition of lamb meat from Northeastern Brazil

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    O objetivo desta pesquisa foi avaliar a composição centesimal e lipídica da carne de ovinos do Nordeste brasileiro. Para isso, foram utilizados 21 borregos, machos inteiros, sendo 10 animais ½ Somalis Brasileira ´ ½ Crioula (SB-C) e 11 animais ½ Santa Inês ´ ½ Crioula (SI-C). Os animais receberam duas dietas durante a fase de amamentação: feno de capim-gramão (Cynodon dactylon) + feno de leucena (Leucaena leucocephala) ad libitum (D1) e feno de capim-gramão + feno de leucena + concentrado com 20% de proteína bruta ad libitum (D2). Não foi observado o efeito dos genótipos nem do sistema de alimentação sobre a composição centesimal e lipídica da carne. Os valores de umidade, proteína, cinzas e gordura, variaram de 76,12 a 76,19%, 19,19 a 19,46%, 1,08 a 1,10% e 2,01 a 2,39%, respectivamente. Os valores de colesterol variaram de 54,43 a 60,05mg por 100g de carne. Os ácidos graxos encontrados em maior quantidade na fração lipídica da carne dos animais estudados foram oleico, palmítico e esteárico. De acordo com os resultados obtidos, conclui-se que a carne de ovinos do Nordeste brasileiro apresenta uma composição centesimal e lipídica similar às carnes de ovinos de clima temperado.<br>The objective of this study was to evaluate the proximate and lipidic compositon of lamb meat from tropical sheep reared in Northeastern Brazil. Twenty-one rams, ten ½ Somalis Brasileira ½ ´ Crioula (SB-C) and 11 ½ Santa Inês ´ ½ Crioula (SI-C) were used. Two feeding regimes were utilized during weaning: grass hay (Cynodon dactylon) + leucena hay (Leucaena leucocephala) ad libitum (D1) and grass háy + leucena hay + 20% crude protein concentrate ad libitum (D2). It was not observed effect of crossbreed or feeding regime on proximate and lipidic composition of the meat. Moisture, protein, ash and fat values varied from 76.12 to 76.19%, 19.19 to 19.46%, 1.08 to 1.10% and 2.01 to 2.39%, respectively. Cholesterol content ranged from 54.43 to 60.05mg/100g of meat. The more abundant fatty acids in lamb fat were oleic, palmitic and stearic. Based on these results, it can be concluded that lamb meat from Notheastern Brazil has proximal and lipidic compositions similar to that animals from temperate regions of the World

    Composição tecidual e centesimal e teor de colesterol da carne de cordeiros terminados em confinamento com dietas contendo níveis crescentes de resíduo úmido de cervejaria Tissue and centesimal composition and cholesterol of the meat of lambs feedlot with diets with different levels of brewery's residue

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    Este estudo teve como objetivo avaliar a influência de diferentes níveis de substituição do alimento concentrado por resíduo úmido de cervejaria sobre a composição tecidual, a composição centesimal e o teor de colesterol da carne de cordeiros terminados em confinamento. Foram utilizados 25 cordeiros, machos, não-castrados, da raça Texel, distribuídos aleatoriamente em cinco tratamentos compostos por níveis de substituição do alimento concentrado por resíduo úmido de cervejaria, sendo: 0%, 25%, 50%, 75% e 100% de substituição. Foram utilizadas uma dieta composta de feno de Tifton-85 e uma mistura concentrada em uma relação volumoso: concentrado de 40:60, com base na matéria seca (MS). O alimento concentrado foi constituído por milho desintegrado, farelo de soja, mistura mineral e resíduo úmido de cervejaria, sendo que suas proporções variaram de acordo com os tratamentos. As dietas foram formuladas para serem isoprotéicas, baseados no teor de proteína bruta (PB) do tratamento com maior nível de resíduo. Os cordeiros foram abatidos após um período experimental de 77 dias. Observou-se, na secção entre a 9&ordf; e a 11&ordf; costelas, que os pesos de osso, músculo e gordura diminuíram linearmente e a proporção de músculo aumentou linearmente com o incremento do nível de resíduo. Verificou-se aumento linear na proporção de umidade no músculo Longissimus dorsi com o aumento do resíduo úmido de cervejaria nas dietas dos cordeiros.<br>The purpose of this experiment was to evaluate the influence of different levels of substitution of the concentrate by brewery's residue on the tissue composition, centesimal composition and cholesterol content in the meat of lambs finished in feedlot. Twenty-five male, non castrated Texel lambs were used, distributed in five treatments, which consisted in the levels of brewery's residue replacing concentrate, being 0%, 25%, 50%, 75% and 100% of substitution. Diet's composition was Tifton-85 hay and concentrate mixture, in a relation roughage:concentrate of 40:60, on dry matter (DM). The concentrate was composed of corn ground grain, soybean meal, mineral mix and brewery's residue, and its proportion varied in accordance with the treatments. The diets were formulated to be isoproteics, based on the crude protein (CP) level of the treatment with the higher level of residue. The lambs were slaughtered after 77 days of experiment. It was observed, in the section between 9th and 11th ribs, that the weights of bone, muscle and fat had linearly decreased, and the proportion of muscle had linearly increased with the increase of the level of the residue. There was a linear increase in the proportion of humidity in the Longissimus dorsi muscle with the increase of the brewery's residue on the lamb's diets
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