1,078 research outputs found
Study of fame production from waste cooking oil: operation in batch and continuous regime with regeneration of enzyme catalyst
This work aimed to: (i) assess the performance of Novozyme® 435 for FAME production from waste cooking oil (WCO) under
different oil acid values and enzyme-to-oil ratios; (ii) test different regeneration methods and assess the regenerated enzyme’s
performance; and (iii) determine FAME yield in continuous operation regime. Oil acid values up to 104 mg KOH.g
-1
and enzymeto-WCO ratios of up to 20:80 (% wt.) were studied, with maximum yield recorded for increasing acid values and enzyme-to-WCO
ratio. FAME production from WCO yield ranging 50-80% was recorded for 5 consecutive production cycles (8h each, in batch
regime) with no regeneration of the enzyme. Among the enzyme regeneration methods tested, the highest FAME yield was recorded
using t-butanol washing followed by enzyme incubation in the WCO before reusing it. Operation in continuous regime, including
enzyme regeneration, produced the highest FAME yield (maximum of 96%). Thus, effectiveness of the regenerating process and
efficiency of continuous production of FAME from WCO (up to 576h) were observed.publishe
Efeito da fertilização mineral fosfatada na partição das formas de fósforo num Regossolo
PTDC/AGR-PRO/112127/2009:
Fitodisponibilidade e riscos ambientais do fósforo aplicado por via de chorumes de pecuária intensiva em solos portugueses.O conhecimento da partição do P no solo por diferentes formas com distinta labilidade, ajuda a perceber a dinâmica do P
não só relativamente à sua fitodisponibilidade, como também a riscos de transferência para as águas com consequências
negativas na eutrofização. Neste trabalho, efetuou-se a caracterização das formas de P presentes num Regossolo e, após
uma adubação mineral fosfatada, avaliou-se o seu efeito sobre a fitodisponibilidade e partição das formas de fósforo. Os resultados
obtidos contribuirão para uma melhor gestão do P no solo.FC
Lepidópteros tortricídeos em pomares de pomóideas e de prunóideas da Beira Interior
Comunicação apresentada no 6.º Encontro Nacional de Protecção Integrada que decorreu em Castelo Branco, na Escola Superior Agrária do Instituto Poliécnico de Castelo Branco, de 14 a 16 de Maio de 2003, no âmbito do painel sobre Prunóideas.Neste trabalho são apresentados resultados de uma prospecção relativa às espécies de tortricídeos fitófagos de
pomares de pomóideas e de prunóideas, na Beira Interior.
O trabalho reporta-se a dados obtidos no ano de 2002, tendo sido utilizadas armadilhas sexuais para as
capturas de adultos e observação visual para a detecção de larvas.
As espécies monitorizadas foram: Adoxophyes orana, Cacoecimorpha pronubana, Pandemis heparana, Pandemis
ribeana (=cerasana) e Cydia molesta. Das cinco espécies monitorizadas apenas houve capturas de Cacoecimorpha
pronubana e de Pandemis heparana. Relativamente a estas duas espécies são apresentadas curvas de voo.
Embora tenham sido detectados frutos com a sintomatologia característica do ataque destas espécies, não
foram encontradas larvas, sugerindo populações economicamente insignificantes no ano de 2002
Fertilizantes orgânicos : efeito na fertilidade do solo e na produção de azevém
Fertilizantes orgânicos : efeito na fertilidade do solo e na produção de azevém
Ciclo do fósforo em agroecossistemas: Efeito da fertilização fosfatada com adubos minerais ou com resíduos orgânicos de pecuária
Comunicação oral da qual só está disponível o resumo.Ciclo do fósforo em agroecossistemas: Efeito da fertilização fosfatada com
adubos minerais ou com resíduos orgânicos de pecuária.Trabalho financiado pelo projeto FCT PTDC/AGRPRO/
112127/2009, “Assessment of phosphorus bioavailability from animal manures
applied to Portuguese soils and site vulnerability to phosphorus losses”, 2011-2013
Balanced scorecard performance assessment in a medical imaging department
The authors present and discuss the development of a strategic management model based on the Balanced Scorecard by Kaplan and Norton to implement in an imaging ward and the relations with Performance Measurement System that allows for the
monitoring of the service's evolution, the alignment of objectives, and the evaluation of individual employees within the strategy of the ward and the hospital
Widespread hybridization between Invasive bleak (Alburnus alburnus) and Iberian chub (Squalius spp.): A neglected conservation threat
Hybridization between native and nonnative fish species is a major conservation issue, especially in ecosystems with high levels of endemism, such as Iberian streams. To date, hybridization with the invasive bleak Alburnus alburnus has been reported for the Iberian chub Squalius alburnoides and S. pyrenaicus and in scattered locations only. However, the bleak is spreading in the region, potentially increasing the risks of hybridization with other Squalius species. To gather a more comprehensive picture on the current geography of hybridization, we compiled records on hybrids between bleak and chub in Portugal and conducted genetical assessments of hybrids between bleak and S. carolitertii. We found that hybridization with bleak is widespread throughout Portuguese river basins and involves at least S. alburnoides, S. pyrenaicus and S. carolitertii. Hybridization with bleak may not only cause waste of reproductive effort and damage the genetic integrity of these endemic species but also promote shifts in the reproductive dynamics of the S. alburnoides hybrid complex, which includes individuals with various ploidy levels and combinations of parental genomes, reproducing sexually and asexually. We recommend that future studies characterize the fitness of bleak hybrids and their ecological and genetic interactions with native fish, in order to design effective conservation measures
Animal manures applied to soil: phosphorus bioavailability, losses to water and erosion
Comunicação oral da qual só está disponível o resumo.Phosphorus (P) is a non renewable resource which highlights the
significance of developing and using alternative sources of P for a sustainable
agriculture. Animal manure is an option but its application to soils to meet crop
nitrogen needs requires careful management practices to minimize freshwater
eutrophication. The aim of this work was to evaluate the partitioning of applied P
between plant uptake, losses to water, and erosion losses when using different
animal manures and a mineral P fertilizer. A field trial was conducted at an erosion
experimental station. The treatments were: Control (0 kg P/ha); cattle manure; solid
fraction of pig and duck slurry and superphosphate, each applied at a rate of 50 kg
P/ha after Lolium sp was sown. Soil samples from each trial were collected over the
9-month study and the water extractable soil P determined. It was found that
desorption of P from all additions rapidly increased soon after P application (2
weeks). After that water extractable soil P remained fairly constant. While duck
slurry desorbed the largest concentration of P, all sources have the potential to
desorb P that could accelerate eutrophication. Plant uptake of P was greater with
cattle manure added and released the least amount of P to water compared with the
other sources of P. The partitioning of applied P between plant uptake and losses to
runoff and sediments ranged between 5-12 % with the higher values in Duck
treatment. Animal manures significantly increased soil Olsen-P, plant production and P
uptake relative to mineral fertilizer. Animal manures can be considered as a source of
available P nevertheless to avoid eutrophication risks increase plant P use efficiency is also
important
Anomalous persistent photoconductivity in Cu2ZnSnS4 thin films and solar cells
A persistent photoconductivity effect (PPC) has been investigated in Cu2ZnSnS4 thin films and solar cells as a function of temperature. An anomalous increase of the PPC decay time with temperature was observed in all samples. The PPC decay time activation energy was found to increase when temperature rises above a crossover value, and also to grow with the increase of the sulfurization temperature and pressure. Both the anomalous behavior of the PPC decay time and the existence of two different activation energies are explained in terms of local potential fluctuations in the band edges of CZTS
Soliton back-action evading measurement using spectral filtering
We report on a back-action evading (BAE) measurement of the photon number of
fiber optical solitons operating in the quantum regime. We employ a novel
detection scheme based on spectral filtering of colliding optical solitons. The
measurements of the BAE criteria demonstrate significant quantum state
preparation and transfer of the input signal to the signal and probe outputs
exiting the apparatus, displaying the quantum-nondemolition (QND) behavior of
the experiment.Comment: 5 pages, 5 figure
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