Time filter

Source Type

Pacheco F.A.L.,Chemistry Research Center | Pacheco F.A.L.,Royal University | Sanches Fernandes L.F.,Center for the Research and Technology of Agro Environment and Biological science
Science of the Total Environment | Year: 2016

Environmental land use conflicts are uses of the land that ignore soil capability. In this study, environmental land use conflicts were investigated in mainland Portugal, using Partial Least Squares (PLS) regression combined with GIS modeling and a group of 85 agricultural watersheds (with >. 50% occupation by agriculture) as work sample. The results indicate a dominance of conflicts in a region where vineyards systematically invaded steep hillsides (the River Douro basin), where forests would be the most appropriate use. As a consequence of the conflicts, nitrate concentrations in rivers and lakes from these areas have increased, sometimes beyond the legal limit of 50. mg/L imposed by the European and Portuguese laws. Excessive nitrate concentrations were also observed along the Atlantic coast of continental Portugal, but associated to a combination of other factors: large population densities, and incomplete coverage by sewage systems and inadequate functioning of wastewater treatment plants. Before this study, environmental land use conflicts were never recognized as possible boost of nitrate concentrations in surface water. Bearing in mind the consequences of drinking water nitrate for human health, a number of land use change scenarios were investigated to forecast their impact on freshwater nitrate concentrations. It was seen that an aggravation of the conflicts would duplicate the number of watersheds with maximum nitrate concentrations above 50. mg/L (from 11 to 20 watersheds), while the elimination of the conflicts would greatly reduce that number (to 3 watersheds). © 2016 Elsevier B.V. Source

Telmo C.,Royal University | Lousada J.,Center for the Research and Technology of Agro Environment and Biological science
Biomass and Bioenergy | Year: 2011

The Higher Heating Value (HHV) of 17 wood fuels was correlated with their Klason lignin (L) and extractive contents (Ext). There was a highly significant correlation between higher heating value, Klason lignin and extractive contents. The HHV (MJ/kg) of wood fuels as a function of lignin and extractive contents can be calculated using the following equation: qv,gr,d = 14.3377 + 0.1228 (L) + 0.1353 (Ext). The correlation coefficient (r) was 0.915. The standard error for Klason lignin was 0.017 and to extractive contents of 0.024. The proportion explained by Klason lignin was 56.4% and explained by extractive contents was 43.6%. © 2011 Elsevier Ltd. Source

Santos M.,Center for the Research and Technology of Agro Environment and Biological science | Cabral J.A.,University of Tras os Montes e Alto Douro
Applied Ecology and Environmental Research | Year: 2011

A simple methodology was applied with the purpose of understanding the effects of anthropogenic disturbances in the biodiversity of landscape patches, namely by using Soil Surface Dwelling Arthropods as relevant indicators in changing scenarios. The goal of the present paper is to apply and extend the above academic concepts to landscape management, and to demonstrate the potential of a Stochastic Dynamic Methodology in implementing the respective actions. Since many of the ecosystem phenomenological aspects are the result of whole-system properties, the main purpose of the Stochastic Dynamic Methodology is to promote a mechanistic understanding of the holistic ecological processes, based on statistical parameter estimation methods. In this perspective, the proposed protocol is compatible with most activities undertaken by conventional ecological science, i.e., pattern seeking, the ability to explain past and present states, and the ability to predict future states. Additionally, in contexts relating to landscape management, the results of the Stochastic Dynamic Methodology applied to monitoring and restoration activities are intuitive and can be easily communicated to non-experts (ranging from students to resource users and senior policy makers). © 2011, ALÖKI Kft., Budapest, Hungary. Source

Morais R.,Center for the Research and Technology of Agro Environment and Biological science | Morais R.,University of Tras os Montes e Alto Douro | Silva N.M.,University of Tras os Montes e Alto Douro | Santos P.M.,University of Tras os Montes e Alto Douro | And 7 more authors.
Sensors and Actuators, A: Physical | Year: 2011

Ever since the first studies about biomedical implantable devices, the problem of how to energize them has stood out as both important and notoriously difficult to solve. In order to extend the lifetime of implants, it is imperative to develop power generators that are autonomous, safe and maintenance-free. Energy harvesting is a natural way of meeting these requirements. First, the energy source is theoretically everlasting, a fact that helps to guarantee the autonomy. Second, the energy is obtained from the environment of the application itself, contributing to its safety. Finally, a properly designed energy harvesting system is very unlikely to ever require maintenance. This paper follows this line and describes an electromagnetic power transducer that harvests electrical energy from the human gait and stores it. An efficient power management module uses the stored energy to energize the telemetric system of a smart hip prosthesis implant, enabling the early detection of loosening, the target application of this work. The system is able to extract a total 1912.5 μJ of usable energy under normal walking conditions. © 2011 Elsevier B.V. All rights reserved. Source

Pacheco F.A.L.,Royal University | Pacheco F.A.L.,Chemistry Research Center | Sanches Fernandes L.F.,University of Tras os Montes e Alto Douro | Sanches Fernandes L.F.,Center for the Research and Technology of Agro Environment and Biological science
Journal of Hydrology | Year: 2013

An assessment of aquifer intrinsic vulnerability was conducted in the Sordo river basin, a small watershed located in the Northeast of Portugal that drains to a lake used as public resource of drinking water. The method adopted to calculate intrinsic vulnerability was the DRASTIC model, which hinges on a weighted addition of seven hydrogeologic features, but was combined with a pioneering approach for feature reduction and adjustment of feature weights to local settings, based on a multivariate statistical method. Basically, with the adopted statistical technique-Correspondence Analysis-one identified and minimized redundancy between DRASTIC features, allowing for the calculation of a composite index based on just three of them: topography, recharge and aquifer material. The combined algorithm was coined vector-DRASTIC and proved to describe more realistically intrinsic vulnerability than DRASTC. The proof resulted from a validation of DRASTIC and vector-DRASTIC by the results of a groundwater pollution risk assessment standing on the spatial distribution of land uses and nitrate concentrations in groundwater, referred to as [. NO3-]-DRASTIC method. Vector-DRASTIC and [. NO3-]-DRASTIC portray the Sordo river basin as an environment with a self-capability to neutralize contaminants, preventing its propagation downstream. This observation was confirmed by long-standing low nitrate concentrations in the lake water and constitutes additional validation of vector-DRASTIC results. Nevertheless, some general recommendations are proposed in regard to agriculture management practices for water quality protection, as part of an overall watershed approach. © 2012 Elsevier B.V. Source

Discover hidden collaborations