25 research outputs found
Nível crítico de ataque das infestantes na cultura do feijão
Dissertação de mestrado em Agronomia. Instituto Politécnico de Beja. Escola Superior Agrária, 2014Pretende-se com este trabalho determinar o período imediatamente anterior do nível crítico de ataque (NCA) das plantas infestantes em feijoeiros submetidos a condições de défice hídrico, utilizando duas abordagens: o nível arbitrário de 5% de perda na produtividade e o nível de tolerância (NT). O ensaio foi conduzido numa parcela cedida pelo COTR-Centro Operativo e de Tecnologia de Regadio, utilizando a variedade de feijão Manata (Fidalgo Anão). Os tratamentos experimentais foram constituídos por cinco períodos de convivência da cultura com as infestantes: 15, 30, 45, 60 dias após a emergência (DAE) e à colheita e mais uma testemunha sem infestantes do início ao fim do ciclo. Adoptou-se o delineamento experimental de blocos causalizados, com quatro repetições. Os níveis críticos de ataque determinados foram de 10 dias para um nível aceitável de 5% de redução arbitrária na produtividade e de 9 dias de competição com as infestantes utilizando o nível de tolerância (NT) que foi de 4.3%, em condições de deficiência hídrica
Resources recovery in the dairy industry: bioelectricity production using a continuous microbial fuel cell
"Available online 19 April 2016"The increasing food demand and the exhaustion of non-renewable fuels provide new market opportunities in the agro-farming sector. Biological systems designed to add value to useless organic sub-products and to generate off-grid electricity may be one of the most interesting outcomes. Therefore, the capacity of some microorganisms to transfer electrons generated during organic carbon oxidation directly to an anode in a so-called microbial fuel cell (MFC) might be an asset in a sustainable management context. In this regard, the main goal of the present work was to evaluate the performance of a continuous MFC applied in a dairy industry. A maximum voltage of 576 mV was produced during continuous operation, corresponding to a power density of 92.2 mW·m-2 or 1.9 W·m-3. MFC was able to remove 1298±617 mg·L-1 of chemical oxygen demand (COD) at a hydraulic retention time of 8.4 h, and the maximum COD removal (63±5 %) was achieved after 20 days of continuous operation. In addition, the coulombic efficiency average was around 10.5±10% with a maximum of 24.2±1.5%. In average, the MFC was able to extract a specific energy of 8.95×102 kWh·kg-1 COD with a maximum output of 20.53×102 kWh·kg-1 COD. In conclusion, the MFC technology is a valuable option for simultaneous wastewater treatment and energy recovery and deserves to be tested and scaled-up in the dairy industry.Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, Project RECI/BBB-EBI/0179/ 2012 (FCOMP-01-0124-FEDER-027462)COMPETE 2020 (POCI- 01-0145-FEDER-006684)Program POPH/ESF - SFRH/BPD/80528/201
Modelação da qualidade da água em lagos vulcânicos: interacção com fluidos de origem magmática
O modelo utilizado decorre do esforço desenvolvido no sentido de se compreender a
dinâmica entre a qualidade da água dos lagos do arquipélago dos Açores e a eventual
interacção com fluidos de origem vulcânica nos sistemas lacustres localizados no interior
de vulcões activos. Com o intuito de utilizar estes sistemas aquáticos na monitorização
vulcânica, recorreu-se ao modelo DYRESM_CAEDYM para se perceber uma entrada
ocasional de carbono inorgânico de origem vulcânico, na Lagoa Verde das Sete Cidades. O
resultado do modelo permitiu constatar que, actualmente, a concentração do carbono
inorgânico dissolvido na água da Lagoa Verde é superior ao modelado, sugerindo que este
excesso de dióxido de carbono seja proveniente de uma entrada no lago de fluidos de
origem vulcânica. Também o resultado dos cenários modelados permitiu compreender o
comportamento do lago face à entrada de grandes concentrações de carbono neste sistema,
resultante de um cenário pré-eruptivo. O modelo é limitado no estudo da Hidrogeoquímica,
não sendo possível modelar o contributo de voláteis nos sistemas aquáticos ou tirar
qualquer ilação relativamente aos processos de interacção água-rocha, nomeadamente na
lixiviação dos metais alcalinos e alcalino-terrosos e do silício. Contudo, para o objectivo
proposto, o programa DYRESM-CAEDYM apresenta potencial na aplicação e exploração
da monitorização vulcânica, nomeadamente na simulação do input do carbono inorgânico.info:eu-repo/semantics/publishedVersio
Immobilization of coagulant Moringa oleifera lectin to remove humic acid from water
Humic acids are linked to carcinogenic by-products formation in water treatment.
In this work coagulant Moringa oleifera lectin (cMoL) immobilized to matrices was
used to remove humic acid from water. Seed proteins were extracted with 0.15 M
NaCl (E) and precipitated with ammonium sulphate (0-60F). Fraction was guar gel
column chromatographed and cMoL was eluted (1.0 M NaCl). E, 0-60F and cMoL
affinity to bind humic acid was characterized using hemagglutinating activity (HA)
with rabbit erythrocytes. Inhibition HA was evaluated with humic acid, humic acid
and calcium or magnesium (5 and 10 mM), carbohydrates and halogenated
compounds. cMoL immobilized in silica, clay, cellulose, agarose and sepharose
was packed into columns. Humic acid (29 mg/L of carbon) was pumped through
columns at 0.2 mL/min. Total organic carbon (TOC) was measured (600 nm) using
the Method 10129 from Hach Lange GmbH (0.0 to 20.0 mg/L of carbon). HA was
detected in E, 0-60F and cMoL. With humic acid SHA decreased 94 % for E and
cMoL; diminished 50 % for 0-60F. K+ enhanced interaction of cMoL with humic
acid in comparison to Ca2+, since a larger decrease of SHA was obtained, 97 %
and 75 %, respectively. D(+)-Galactose and L(+)-arabinose inhibited cMoL SHA by
87.5 %. Trichloroacetic acid, dicholoroacetic acid and chloroform had no activity
effect. The highest amount of cMoL was immobilized on cyanogen bromideactivated
Sepharose 4B, 2.4 g/mg, followed by cyanogen bromide-activated
Agarose, 0.2 g/mg. A considerable humic acid removal was obtained in the new
purification protocol.info:eu-repo/semantics/publishedVersio
Preparação de lectinas de Moringa oleifera com atividade coagulante
info:eu-repo/semantics/publishedVersio
COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study
Background:
The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms.
Methods:
International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms.
Results:
‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country.
Interpretation:
This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men
Simulação de um caso de tratamento de efluentes vinícolas
Esta apresentação incide sobre o processo de instalação de uma unidade de tratamento de efluentes líquidos numa empresa vitivinicola. Para esse efeito e por forma a analisar alguns pontos essencias nesse processo, configurou-se um caso de estudo de uma unidade industrial que é confrontada com a necessidade de fazer face à problemática do tratamento de efluentes.info:eu-repo/semantics/publishedVersio
Inventário nacional de resíduos industriais: relatório final
O presente Inventário Nacional de Resíduos Industriais é constituído pelos seguintes volumes:
Volume 1 - Levantamento de Informação de Base - Trabalho de Campos;
Volume II - Indicadores de Produção de Resíduos.info:eu-repo/semantics/publishedVersio
Nanoporous, aluminium-supported alumina membrane, method for producing same and use thereof
International PatentThe present invention describes a membrane for removing anions from liquid media, preferably phosphorus, comprising an aluminium metal structure containing: an inner layer with two faces, made of non-anodized and non-porous aluminium; an outer layer that coats the inner layer and contains anodized aluminium oxide with nanoporosities, the pores in the nanoporosities having an essentially rectilinear structure. Also described in this patent application are the method for producing said membrane and the use of the membrane.info:eu-repo/semantics/publishedVersio