Quantification of EEG Brain Activity in the Self-Paced Regime

Joana Silva, A. Martins da Silva, Luís Coelho

1-8

The processing of motor, sensory and cognitive information by the brain can result in changes of the electroencephalogram (EEG) by Event Related Desynchronization (ERD) or Event Related Synchronization (ERS). The first one concerns a decrease in the amplitude of a rhythmic activity while the second corresponds to its increase. The analysis of these two phenomena in specific frequency bands - alpha (8-13 Hz) and beta (14-30 Hz) - allows the understanding of the cerebral activity. This study focuses on the quantification of cerebral activity by determining the ERD and ERS on the referred band, induced by self-paced movements, by using EEGLAB and MATLAB tools. This was achieved by the creation of a new and automatic quantification algorithm. The results indicate that a greater desynchronization of the signal is accompanied by a decrease in the amplitude of the same. As a conclusion, the cerebral activity varies in terms of synchronization and desynchronization among certain frequency bands in several zones, according to the tasks performed.

Structural Characterization of Heat Treated Poplar Wood

Gonçalo Monteiro

9-26

Wood has been very useful in many fields due to its excellent properties. However, it also has less attractive characteristics, like high hygroscopicity and low bioconversion efficiencies. Heat treatment has been proved to improve these properties making lignocellulosic materials a stronger alternative to non-renewable sources to produce energy and other products. This study focused on the structural changes of heat treated poplar (populus) wood specimens treated under different temperature conditions. Nitrogen adsorption, pore size distribution and specific surface area of heat treated wood were studied. Increasing the temperature of treatment leads to a change on the characteristics of the nitrogen adsorption isotherms. The volume of pores for samples treated at higher temperatures is much greater comparing with samples below 400 oC BET specific surface areas were generally low for samples at temperatures until 400 oC, after this a great increase occurred while increasing temperatures up to 500 oC (413,06 m2/g).

Methods for Measuring Association between Intervention for Increasing Movement and Productivity

Systematic Review

Sara Maheronnaghsh, Joana Santos, António Torres Marques, Mário Vaz

27-41

Aim: The purpose of this systematic literature review is to check papers to find the best method for measuring association between health interventions and productivity and find best intervention in workplace for increasing productivity.
Method: This systematic review was performed based on PRISMA statement methodology and performed on all papers about association between productivity with intervention for increasing physical activity, published from 2007 until June 2017. The search was limited to English language items.
Conclusion: The results of this systematic review demonstrate that providing interventions for workers in various workplaces have a low to high affecting on productivity, as measured by objective and organization specific metrics or subjective and self-report questionnaires. The Analyze of result showed that using different methods simultaneously can make more accuracy and precision. Also it’s better that before filling the self-report questionnaires researchers train all workers about the purpose of the study.

Planning Models for Distribution Grid

A Brief Review

Piedy Agamez Arias

42-55

planning and expansion models of the electrical grid to guarantee mainly the energy supply for current and future loads and the technical and operational criteria of the grid, requiring for this, to make an orderly sequence of investments along the planning horizon. Nevertheless, the ongoing integration of distributed generation and energy storage devices has been leading to consider some changes on those models focus to deal with the complexity those integrations bring with them. In this context, this paper presents a brief review of distribution planning and expansion models with the perspective of identifying approaches, objective functions used, uncertainties analyzed, the computational and evolutionary techniques used, the dimension of the grid under analyses, among other aspects considered to solve the planning and expansion problem. This document will provide a background to find out the further works in this field.

Occupational Vibration in Urban Bus and Influence on Driver’s Lower Limbs

A Short Review

M. Cvetkovic, J. Santos Baptista, M. A. Pires Vaz

56-66

The whole-body vibration occurs in many occupational activities, promoting discomfort in the working environment and inducing a variety of psycho – physical changes where consequences as a permanent dysfunction of certain parts of the organism may occur. The main goal of this short systematic review is finding the articles with the most reliable results relating whole-body vibrations to buses and, to compare them with the results of drivers’ lower limbs musculoskeletal disease which occurs as a consequence of many year exposure. PRISMA Statement Methodology was used and thereby 27 Scientific Journals and 25 Index - Database were searched through where 3996 works were found, of which 24 were included in this paper. As a leading standard for analysis of the whole-body vibration the ISO 2631 – 1 is used, while in some papers as an additional standard the ISO 2631-5 is also used for the sake of better understanding the vibrations. Furthermore, the European Directive 2002/44 / EC is included where a daily action exposure to the whole-body vibrations is exactly deter-mined. All the results presented in the paper were compared with the aforesaid standards. After having searched the databases, papers that deal with research of the impact of the vibration on the driver’s lower limbs did not contain any information’s on the described problem.

Second Generation Ethanol - Technological Intensity on the Integrated Cycle

Pedro P. Senna, Stela L. M. Ansanelli

67-76

The purpose of this study is to investigate Second Generation Ethanol’s (SGE) production cycle in order to understand the level of SGE’s technological intensity in the integrated cycle. The suggested methodology comprises of a review of literature surrounding the requirements and indexes of technological intensity. A wide selection of database and review of specialized literature have been described to demonstrate the proposed discussion and conclusions. It has been observed that SGE puts forward a higher level of technological intensity in relation to First Generation Ethanol (FGE).

Dimensioning Studies for Reversible Hydro Power Plants in Portuguese Islands

Nuno Fonseca, André Madureira, João Peças Lopes, Manuel Matos

77-86

This work is within the scope of set of consultancy studies made for Portuguese islands. It focuses on the integration of Pumped Storage Power in isolated islands. The paper starts to address several power systems circumstances about two Portuguese islands on the energetic level. For each of these islands, an independent examination of the conditions to install a reversible hydro power plant is accomplished. Therefore, the energy volume to be stored due to excess of renewable generation and the ideal power and number of the pumps and turbines to be installed were identified and evaluated for the sake of using the produced energy surplus as to be pumped and later generated. The paper enhances the importance of storing energy in the operation of isolated and small systems with considerable amount of intermittent power resources as well as the conditions for the viability of installing new exploitations of this kind.