1000 resultados para decisão fazer versus comprar


Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this study, we concentrate on modelling gross primary productivity using two simple approaches to simulate canopy photosynthesis: "big leaf" and "sun/shade" models. Two approaches for calibration are used: scaling up of canopy photosynthetic parameters from the leaf to the canopy level and fitting canopy biochemistry to eddy covariance fluxes. Validation of the models is achieved by using eddy covariance data from the LBA site C14. Comparing the performance of both models we conclude that numerically (in terms of goodness of fit) and qualitatively, (in terms of residual response to different environmental variables) sun/shade does a better job. Compared to the sun/shade model, the big leaf model shows a lower goodness of fit and fails to respond to variations in the diffuse fraction, also having skewed responses to temperature and VPD. The separate treatment of sun and shade leaves in combination with the separation of the incoming light into direct beam and diffuse make sun/shade a strong modelling tool that catches more of the observed variability in canopy fluxes as measured by eddy covariance. In conclusion, the sun/shade approach is a relatively simple and effective tool for modelling photosynthetic carbon uptake that could be easily included in many terrestrial carbon models.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dissertação de mestrado em Marketing e Estratégia

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Tese de Doutoramento em Estudos da Criança (área de especialização em Educação Musical).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Programa Doutoral em Engenharia Industrial e de Sistemas.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dissertação de mestrado em Engenharia Industrial

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dissertação de mestrado em Systems Engineering

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dissertação de mestrado em Engenharia de Sistemas

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dissertação de mestrado integrado em Engenharia e Gestão de Sistemas de Informação

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Several suction–water-content (s-w) calibrations for the filter paper method (FPM) used for soil-suction measurement have been published. Most of the calibrations involve a bilinear function (i.e., two different equations) with an inflection point occurring at 60 kPa

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Phenolic acids are present in our diet in different foods. In particular, mushrooms are a good source of these molecules. Due to their bioactive properties, phenolic acids are extensively studied and there is evidence of their role in disease prevention. Nevertheless, in vivo, these compounds are metabolized and circulate in the organism as glucuronated, sulfated and methylated metabolites, displaying higher or lower bioactivity. To clarify the importance of the metabolism of phenolic acids, the knowledge about the bioactivity of the metabolites is extremely important. In this review, chemical features, biosynthesis and bioavailability of phenolic acids are discussed as well as the chemical and enzymatic synthesis of their metabolites. Finally, the metabolites bioactive properties are compared with that of the corresponding parental compounds.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dissertação de mestrado integrado em Engenharia Biomédica (área de especialização em Engenharia Clínica)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dissertação de mestrado integrado em Engenharia e Gestão de Sistemas de Informação

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This article presents results of an experimental investigation on the resistance to chemical attack (with sulphuric, hydrochloric and nitric acid) of several materials: OPC concrete, high-performance concrete, epoxy resin, acrylic painting and a fly ash-based geopolymeric mortar). Three types of acids with three high concentrations (10, 20 and 30%) were used to simulate long-term degradation. A cost analysis was also performed. The results show that the epoxy resin has the best resistance to chemical attack independently of the acid type and the acid concentration. However, the cost analysis shows that the epoxy resin-based solution is the least cost-efficient solution being 70% above the cost efficiency of the fly ash-based geopolymeric mortar.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dissertação de mestrado integrado em Engenharia e Gestão de Sistemas de Informação

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dissertação de mestrado integrado em Engenharia de Gestão e Sistemas de Informação