7,052 research outputs found
Estimation of water use and crop coefficients for an intensive olive orchard using sap flow measurements and modeled data
Olive tree sap flow measurements were collected in an intensive orchard near Évora, Portugal, during the irrigation seasons of 2013 and 2014, to calculate daily tree transpiration rates (T_SF). Meteorological variables were also collected to calculate reference evapotranspiration (ETo). Both data were used to assess values of basal crop coefficient (Kcb) for the period of the sap flow observations. The soil water balance model SIMDualKc was calibrated with soil, biophysical ground data and sap flow measurements collected in 2013. Validated in 2014 with collected sap flow observations, the model was used to provide estimates of dual e single crop coefficients for 2014 crop growing season. Good agreement between model simulated daily transpiration rates and those obtained with sapflow measurements was observed for 2014 (R2=0.76, RMSE=0.20 mm d-1), the year of validation, with an estimation average absolute error (AAE) of 0.20 mm d-1. Olive modeled daily actual evapotranspiration resulted in atual ETc values of 0.87, 2.05 and 0.77 mm d-1 for 2014 initial, mid- and end-season, respectively. Actual crop coefficient (Kc act) values of 0.51, 0.43 and 0.67 were also obtained for the same periods, respectively. Higher Kc values during spring (initial stage) and autumn (end-stage) were published in FAO56, varying between 0.65 for Kc ini and 0.70 for Kc end. The lower Kc mid value of 0.43 obtained for the summer (mid-season) is also inconsistent with the FAO56 expected Kc mid value of 0.70 for the period. The modeled Kc results are more consistent with the ones published by Allen & Pereira [1] for olive orchards with effective ground cover of 0.25 to 0.5, which vary between 0.40 and 0.80 for Kc ini, 0.40–0.60 for Kc mid with no active ground cover, and 0.35–0.75 for Kc end, depending on ground cover. The SIMDualKc simulation model proved to be appropriate for obtaining evapotranspiration and crop coefficient values for our intensive olive orchard in southern Portugal
Integration of lean manufacturing and ergonomics in a metallurgical industry
Striving to improve productivity, industries have used different management approaches, being lean manufacturing the most used over recent years. Lean manufacturing is based on value creation for the customer and elimination of waste that occurs during the production process, while improving working conditions. The incorporation of ergonomic aspects in the workstation design also contributes for the referred objectives, since it will reduce awkward postures or excessive effort during work, leading to better working conditions and increased productivity. The present study highlights, through a case study in four production areas of a metallurgical industry, the benefits of using an integrated operations management approach to improve productivity and ergonomic aspects. Several ergonomic methods, such as Rapid Upper Limb Assessment (RULA), Strain Index (SI), and Rapid Entire Body Assessment (REBA), were chosen to evaluate the ergonomic situation and lean manufacturing tools such as Value Stream Mapping (VSM) and 7 wastes were also used to analyze the systems and increase the productivity by eliminating several wastes. The results of this study show that it is possible, and desirable, to consider both aspects, ergonomic conditions and productivity, during continuous improvement’ implementations. In fact, the improvements reached through the advances in ergonomic conditions can contribute very positively for productivity increasing.info:eu-repo/semantics/publishedVersio
Populational analysis of Saccharomyces cerevisiae strains from different appellations of origin and grape varieties by microsatellite analysis.
The objective of the present study was to evaluate populational relationships among Saccharomyces cerevisiae strains isolated from some of the Portuguese most important grapevine varieties in different appellations of origin, using polymorphic microsatellites. 
One hundred ninety two grape samples were collected during the 2006 and 2007 harvest season in the Vinho Verde (grape varieties: Arinto, Alvarinho, Avesso, Loureiro, Touriga Nacional) Bairrada (grape varieties: Arinto, Baga, Castelão Francês, Maria Gomes, Touriga Nacional) Alentejo (grape varieties, Aragonês, Trincadeira, Touriga Nacional), Terras do Sado (grape variety Castelão) Bucelas (grape variety Arinto) and Estremadura (grape varieties: Arinto, Aragonês, Castelão, Trincadeira, Touriga Nacional) appellations of origin. From the final stage of spontaneous fermentations, 2820 yeast isolates were obtained, mainly belonging to the species S. cerevisiae. An initial genetic screen, based on mitochondrial DNA restriction fragment length polymorphism (mtDNA RFLP) and/or interdelta sequence analysis was followed by microsatellite analysis of strains with unique genetic profiles, using 10 highly polymorphic microsatellites. Our results showed that microsatellite analysis revealed a high resolution populational screen, showing that genetic differences and populational structures among S. cerevisiae populations derived from both “diagnostic” vineyard-, specific alleles and the accumulation of small allele-frequency differences across ten microsatellite loci. Heterozygosity was three to four times lower than the expected value, confirming the strong populational substructuring. The presented large-scale approach shows that each vineyard contains differentiated S. cerevisiae populations, showing the occurrence of specific native strains that can be associated with a terroir. 

Financially supported by the programs POCI 2010 (FEDER/FCT, POCTI/AGR/56102/2004) and AGRO (ENOSAFE, Nº 762).

Cross-cultural adaptation of the Child Perceptions Questionnaire 11–14 (CPQ11–14) for the Brazilian Portuguese language
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Effect of criteria weighting methods on the ranking of water suppliers’ performance
Water supply systems are a structural part of public utilities and as such are vital to the general well-
being, public health, safe drinking water use, economic activities and environment protection. Being the water
“market” a natural monopoly, regulation must, mainly, protect the interests of the user, based on a
benchmarking strategy that promotes the quality of the water supply service and assuring the balance of the
ruling tariffs.
Due to the complexity of service quality assessment, the use of performance indicators is essential as a means
to provide a measure the utility’s effectiveness and efficiency. In Portugal, this task is conducted by an
independent public entity, which has defined a specific set of performance indicators. Currently, the adopted
system does not provide a quantitative and integrated evaluation leading to an overall ranking of utilities’
performance and sustainability.
This work aims to contribute to the improvement of the Portuguese assessment system, through the
development of a complementary methodology that defines a global index of service quality (GISEQ) for a
given water supply utility, based on a new application of multicriteria analysis. The GISEQ value is calculated
as a combination of the normalized scores of each performance indicator, previously aggregated in three main
groups: protection of user interests, sustainability of the utility and environmental sustainability. In this
proposed methodology, each one of the selected performance indicators represents a criterion to be considered
and judiciously weighted. An innovative approach to weights definition was performed as well as a sensitivity
analysis of different weighting methods on water supply utilities’ ranking positions
Monitoring programmes: the fundamental component of estuaries management: how to design one?
This article focuses on the design of a conceptual framework to design and
assess environmental estuarine monitoring programmes, including the networks,
to detect quality status changes in coastal areas within environmental
management programmes. Monitoring is a fundamental component in any
management system, and in particular in sensitive areas under strong human
pressures, like estuaries. These pressures will be reflected in impacts in the
ecosystem and also in responses from it. A monitoring program including the
network and the indicators measured, should be designed to be able to identify
the i) pressures, ii) the state and effects, and iii) the responses of human action in
the estuary according to casualty chains, also the monitoring performance should be measured to assess the effectiveness of the monitoring program itself.
Answers to these needs are studied in this article, namely in what concerns the
selection and location of the monitoring stations. To evaluate the “best”
monitoring design one should first clearly identify the objectives of the network
and which indicators (in the sense of important variables that reflect
environmental attributes) are most appropriate for the particular situation. In this
work two methods for monitoring network design will be evaluated, namely i)
variance-reduction based, and ii) space-filling. These two are examples of a
statistically-based method, and of a random-allocation-based method. The most
appropriate objective functions are used to reflect the objectives of the
monitoring. In all cases the objective function models are solved with the
simulated annealing meta-heuristic algorithm, implemented by the team to solve
monitoring optimisation problems. Due to the amount and quality of the
information available, the Sado estuary is used as a case-study to demonstrate the
results of the methods and helping in the comparative analysis.info:eu-repo/semantics/publishedVersio
First-Principles Model to Evaluate Quantitatively the Long-Life Behavior of Cellulose Acetate Polymers
UIDB/04028/2020
UIDP/04028/2020
UID/QUI/50006/2019A deep understanding of the degradation of cellulose diacetate (CDA) polymer is crucial in finding the appropriate long-term stability solution. This work presents an investigation of the reaction mechanism of hydrolysis using electronic density functional theory calculations with the B3LYP/6-31++G*∗ level of theory to determine the energetics of the degradation reactions. This information was coupled with the transition-state theory to establish the kinetics of degradation for both the acid-catalyzed and noncatalyzed degradation pathways. In this model, the dependence on water concentration of the polymer as a function of pH and the evaporation of acetic acid from the polymer is explicitly accounted for. For the latter, the dependence of the concentration of acetic acid inside the films with the partial pressure on the surrounding environment was measured by sorption isotherms, where Henry's law constant was measured as a function of temperature. The accuracy of this approach was validated through comparison with experimental results of CDA-accelerated aging experiments. This model provides a step forward for the estimation of CDA degradation dependence on environmental conditions. From a broader perspective, this method can be translated to establish degradation models to predict the aging of other types of polymeric materials from first-principles calculations.publishersversionpublishe
- …