Recursos de colección

UTL Repository Universidade Técnica de Lisboa (37.000 recursos)

O Repositório Institucional da Universidade Técnica de Lisboa desenvolvido no âmbito do projecto RCAAP. Este repositório destina-se a recolher, preservar e disponibilizar o acesso às publicações científicas e didácticas de seis: Escolas da UTL: Faculdade de Medicina Veterinária, Instituto Superior de Agronomia, Instituto Superior de Economia e Gestão, Instituto Superior de Ciências Sociais e Políticas , Faculdade de Motricidade Humana, Faculdade de Arquitectura. O Instituto Superior Técnico, igualmente Escola Da UTL, tem repositório independente.

Mostrando recursos 1 - 20 de 26

  1. OliveCan: a process-based model of development, growth and yield of olive orchards

    López-Bernal, Álvaro; Morales, Alejandro; Garcia-Tejera, Omar; Testi, Luca; Orgaz, Francisco; Melo-Abreu, J.P.; Villalobos, Francisco J.
    Original Research

  2. Shelf-life of reduced-fat white chocolate fillings using iota-carrageenan

    Dias, João; Alvarenga, Nuno; Sousa, Isabel
    Regular Article

  3. Potential bio-activity of whey fermented extract as sanitizer of organic grown lettuce

    Santos, M.I.S.; Martins, S.R.; Pedroso, L.; Sousa, I.; Ferreira, M.A.S.S.
    Short Communication

  4. Phytotoxic metabolites from Neofusicoccum parvum, a pathogen of Botryosphaeria dieback of grapevine

    Abou-Mansour, Eliane; Débieux, Jean-Luc; Ramírez-Suero, Montserrat; Bénard-Gellon, Mélanie; Magnin-Robert, Maryline; Spagnolo, Alessandro; Chong, Julie; Farine, Sibylle; Bertsch, Christophe; L'Haridon, Floriane; Serrano, Mario; Fontaine, Florence; Rego, Cecilia; Larignon, Philippe
    Liquid chromatography-diode array screening of the organic extract of the cultures of 13 isolates of the fungus Neofusicoccum parvum, the main causal agent of botryosphaeria dieback of grapevine, showed similar metabolites. One strain was selected for further chemical studies and led to the isolation and characterisation of 13 metabolites. Structures were elucidated through spectroscopic analyses, including one- and two-dimensional NMR and mass spectrometry, and through comparison to literature data. The isolated compounds belong to four different chemical families: five metabolites, namely, ( )-terremutin (1), (+)-terremutin hydrate (2), (+)-epi-sphaeropsidone (3) ( )-4-chloro-terremutin hydrate (4) and(+)-4- hydroxysuccinate-terremutin hydrate (5), belong to the family of dihydrotoluquinones; two metabolites, namely, (6S,7R) asperlin...

  5. Novel mango bars using gellan gum as gelling agent: rheological and microstructural studies

    Danalache, Florina; Mata, Paulina; Martins, Margarida Moldão; Alves, Vitor D.
    This work aimed the development of mango bars, made with fresh mango puree and gellan gum. The influence of gellan concentration as well as the ratio of LA (low-acyl) and HA (high-acyl) gellan on the rheological and microstructural properties of the mango bars was studied. Rheological outcomes showed that both LA and HA, and in mixtures, were able to produce jellified products, within a rather low maturation time. Furthermore, a synergistic effect was observed at different ratios of LA/HA, enabling the production of mango bars with intermediate viscoelastic properties. Higher values of the dynamic moduli were perceived as the LA content increased. Confocal microscopy is in...

  6. Performance assessment of the FAO AquaCrop model for soil water, soil evaporation, biomass and yield of soybeans in North China plain

    Paredes, P.; Wei, Z.; Liu, Y.; Xu, D.; Xin, Y.; Zhang, B.; Pereira, L.S.
    tFour years of soybean experimental data observed at Daxing, North China Plain, were used to assess theability of the AquaCrop model to predict soybean final biomass and yield. The model was parameterizedand calibrated using field data on leaf area index (LAI), available soil water, soil evaporation, biomass andfinal yield data. The model was assessed using calibrated and default parameters. Data on LAI were usedto derive the fraction of ground cover and to calibrate the green canopy cover (CC) curve. An accurate cal-ibration of the CC curve was performed, with low root mean square errors (RMSE < 7.3%). Results relativeto soil...

  7. Modelling soil water dynamics of full and deficit drip irrigated maize cultivated under a rain shelter

    González, Maria G.; Ramos, Tiago B.; Carlesso, Reimar; Paredes, Paula; Petry, Mirta T.; Martins, Juliano D.; Aires, Núbia P.; Pereira, L.S.
    Research Paper

  8. Fe deficiency induction in Poncirus trifoliata rootstock growing in nutrient solution changes its performance after transplant to soil

    Gama, Florinda; Saavedra, Teresa; Díaz, Isabel; Campillo, Maria del Carmen; Varennes, Amarilis de; Duarte, Amílcar; Pestana, Maribela; Correia, José Pedro
    tThe absence of iron (Fe) in the nutrient solution induces several physiological and morphological adapta-tions in the roots of Poncirus trifoliata, a citrus rootstock, thereby modifying its overall nutritional status.Whether these changes are advantageous when plants are transplanted to calcareous soils needs to beassessed. To achieve this objective a two-phase experiment was established, first in nutrient solution(phase I) then in pots containing different soils (phase II). In phase I, P. trifoliata L. Raf. plants were grownin Hoagland’s solution with 120 M of Fe (Fe120 treatment) or without (Fe0 treatment). At the end ofphase I (87 days), Fe-chlorotic plants had less...

  9. Effect of modified atmosphere on polyphenols during storage of pasteurised strawberry purees

    Oliveira, Ana; Alexandre, Elisabete M.C.; Coelho, Marta; Gomes, Maria Helena; Almeida, Domingos P.F.; Pintado, Manuela
    The minimum loss of processed fruit nutritional quality must been guaranteed during storage and the atmosphere can be a limiting step. Strawberry pur ees flushed with gas mixtures: 10 kPa O2 þ 90 kPa N2, 100 kPa N2 and air (78 kPa N2 þ 21 kPa O2 þ 0.03 kPa CO2) were stored for 90 days at 4 and 23 C and revealed no effect in total antioxidant activity and in total phenolic content. The compounds (þ)-catechin, ( )-epicatechin and quercetin-3-rutinoside were not affected by the atmospheres for both temperatures and ellagic acid was the exception within strawberry phytochemicals, where its concentration was higher for samples...

  10. The portuguese agrifood traditional products: main constraints and challenges

    Rodrigo, Isabel; Cristovão, Artur; Tibério, Manuel Luís; Baptista, Alberto; Maggione, Lara; Pires, Miguel
    Study developed under the Rural Natework Project “Observatório de sistemas de produção localizados e valorização de produtos locais; Identificação, análise e divulgação de boas práticas de comercialização e valorização de produtos agro-alimentares tradicionais” (PNRR: PA 0400157-58-59)

  11. Evaluation of olive flowering at low latitutde sites in Argentina using a chilling requirement model

    Aybar, Vanessa E.; Melo-Abreu, J.P.; Searles, Peter S.; Matias, Angel C.; Del Rio, Carmen; Caballero, Juan M.; Rousseaux, M.Cecilia
    Research Article

  12. Percepção dos consumidores relativamente à carne de bovino: critérios de escolha a partir de grupos de discussão

    Viegas, Inês; Santos, José Manuel Lima; Fontes, Magda Aguiar
    Nas economias desenvolvidas, a segurança dos alimentos, o bem‑estar animal e o ambiente têm vindo a assumir relevância nas preocupações dos consumidores. Procurámos saber, através da metodologia dos grupos de discussão (focus groups) realizados em duas cidades de Portugal, Lisboa e Porto, as preocupações e perceções dos consumidores relativamente a estes atributos, os quais são essencialmente acreditados. Este conhecimento é fundamental para a aplicação posterior de métodos de preferências declaradas. Foi ainda possível obter, com base em exercícios de seleção entre carnes diferenciadas, e através de um modelo logit, intervalos de preços passíveis de serem utilizados posteriormente na definição de...

  13. Shared and divergent pathways for flower abscission are trggered by gibberellic acid and carbon starvation in seedless Vitis

    Domingos, Sara; Fino, Joana; Cardoso, Vânia; Sánchez, Claudia; Ramalho, José C.; Larcher, Roberto; Paulo, Octávio S.; Oliveira, Cristina M.; Goulão, Luis F.
    Research Article

  14. Evaluation of parasitism and predation of Tuta absoluta (Meyrick, 1917) (Lepidoptera: Gelechiidae) by Diglyphus isaea (Walker, 1838) (Hymenoptera: Eulophidae)

    Payer, R.; Figueiredo, E.; Mexia, A.
    To evaluate an eventual parasitism and/or predation behaviour of the eulophid parasitoid Diglyphus isaea (Walker, 1838) on Tuta absoluta (Meyrick, 1917) larvae two assays were performed releasing adult parasitoids. The first assay was conducted in Petri dishes using tomato leaflets havig mines with T. absoluta larvae inside. The second, was performed on previously infested potted tomato plants. In both assays no parasitism but only predation was found. Predation was observed, mainly on L2 and L3 larvae which had moulted. Proportion of clearly preyed larvae reached 17% in Petri dishes and 38% in potted plants. Predation was attested by the presence of punctures done by the oviscapt...

  15. Polyphenoloxidase activity and browning in fresh-cut "Rocha" pear as affected by pH, phenolic substrates and antibrowning additives

    Gomes, M.Helena; Vieira, Tiago; Fundo, Joana F.; Almeida, Domingos P.F.
    tThe effect of pH, phenolic substrates, and food additives on polyphenoloxidase (PPO) activity and ontissue browning was studied in fresh-cut ‘Rocha’ pear. Substrates 4-methylcatechol, caffeic acid, (+)-catechin hydrate, catechol, chlorogenic acid, dopamine hydrochloride, and pyrogallol, were preparedin citric acid-phosphate buffer at pHs ranging from 3.0 to 8.0. pH optima for PPO activity dependedon the phenolic substrate. Activity was optimal at pH 5.0 for catechol and 4-methylcatechol; pH 6.0 forchlorogenic acid; pH 7.0 for dopamine, caffeic acid, and catechin; and pH 8.0 for pyrogallol. Discrepancieswere observed between the pH dependency of PPO activity and browning, as assessed by objective colormeasurement. Significant...

  16. Effects of azoxystrobin, chlorothalonil and ethoprophos on the reproduction of three terrestrial invertebrates using a Mediterranean soil

    Leitão, Sara; Cerejeira, M. José; Van den Brink, Paul J.; Sousa, José Paulo
    The potential terrestrial toxicity of three pesticides, azoxystrobin, chlorothalonil, and ethoprophos was evaluated using reproduction ecotoxicological tests with different non-target species: the collembolan Folsomia candida, the earthworm Eisenia andrei, and the enchytraeid Enchytraeus crypticus. All reproduction tests were performed with natural soil from a Mediterranean agricultural area (with no pesticide residues) in order to improve the relevance of laboratory data to field conditions. Controls were performed with natural and standard artificial soil (OECD 10% OM). The fungicide azoxystrobin showed the highest toxicity to earthworms (EC50 = 42.0 mg a.i. kg−1 dw soil). Collembolans were the most sensitive taxa in terms of sublethal effects of chlorothalonil with an...

  17. Effects of organic/inorganic amendments on trace elements dispersion by leachates from sulfide-containing tailings of São Domingos mine, Portuga. Time evaluation

    Santos, Erika S.; Magalhães, Maria Clara F.; Abreu, Maria Manuela; Macías, Felipe
    Greenhouse pot experiments were conducted over 13 months to evaluate the effect of two amendment mixture doses (30 and 75 Mg/ha) on the geochemical dispersion of trace elements by leaching hazardous mine wastes from the São Domingos mine. Mineralogical evolution of these materials was also evaluated. Amendment mixtures containing solid wastes from agriculture (plant remains + strawberry substrate and rockwool used for the strawberry crop) and fromdistillation of Ceratonia siliqua L. and Arbutus unedo L. fruitswere used to improve the chemical characteristics of leachates fromsulfide minewastes. Sulfide mine wastes had acidic characteristics, aswell as high electrical conductivity and total element concentrations (g/kg; Al: 54.8–61.2; Fe: 104.0–110.0;...

  18. Drip vs. surface irrigation: a comparison focussing on water saving and economic returns using multicriteria analysis applied to cotton

    Darouich, Hanaa M.; Pedras, Celestina M.G.; Gonçalves, José M.; Pereira, L.S.
    Research Paper

  19. Development of ternary diagrams for estimating water retention properties using geostatistical approaches

    Ramos, T.B.; Horta, A.; Gonçalves, M.C.; Martins, J.C.; Pereira, L.S.
    Most pedotransfer functions (PTFs) have adopted soil texture information as the main predictor to estimate soil hydraulic properties, whether inputs are defined in terms of the relative proportion of different grain size particles or texture-based classifications. The objective of this studywas to develop ternary diagrams for estimating soil water retention (θ) at−33 and−1500 kPa matric potentials, corresponding to the field capacity and wilting point, respectively, from particle size distribution using two geostatistical approaches. The texture triangle was divided into a 1% grid of soil texture composition resulting in 4332 different soil textures. Measured soil water retention values determined in 742 soil horizons/layers located in Portugal were...

  20. The use of biodegradable mulch films on stawberry crop in Portugal

    Costa, Raquel; Saraiva, Artur; Carvalho, Lopo; Duarte, Elizabeth
    tThe use of plastic mulch films in agriculture had its beginning in the middle of last century andsince then its use has been intensified, with all the environmental problems related to their disposal.The biodegradable mulch films, which can be incorporated in the soil at the end of the crop cycle,appear as a possible solution for this problem. The goal of this work was to assess the performanceof five biodegradable mulch films when comparing to conventional polyethylene (PE), in strawberryproduction (Fragaria × ananassa Duch.). The field tests were performed for two years in the region ofRibatejo—Portugal. Taking into account that there...

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