Neotectonic activity on the Carcavai fault zone (Algarve, Portugal)

Studies performed on the Carcavai fault zone, Eastern Algarve, revealed several deformational features in Plio-Quaternary sediments with potential neotectonic implications. These features include fracturing (faults and joints) and clastic dikes, located along the Carcavai fault. Most of the fractures appear to be the expression of the fault activity affecting the Plio-Quaternary sediments. This is suggested by a consistent strike, subparallel to the major tectonic structure, and by the location pattern. Evidences of the fault activity were also identified in the Mesozoic and Paleozoic rocks, though the age of that deformation is poorly constrained. It consists in the presence of zones of intensely brecciated rock and of adjoining coarse sedimentary deposits probably related to the dismantling of a fault scarp. The acquired data point to a late hercynian structure, reactivated as a left-lateral strike-slip fault with a thrust component during the Plio-Quaternary

Estudos de neotectónica na falha de Carcavai, Algarve Oriental

Estudos levados a cabo na zona da falha de Carcavai revelaram a ocorrência de deformações (fracturação e filões detríticos) em sedimentos plio-quaternários, indicando actividade neotectónica. A generalidade das fracturas aparenta corresponder à expressão superficial secundária da actividade naquela zona de falha. Os dados adquiridos apontampara uma zona de falha complexa de desligamento esquerdo, com componente vertical inversa, desde o final do Mesozóico ou início do Cenozóico. Os filões detríticos foram interpretados como estruturas resultantes de liquefacção induzida sismicamente

Como é que os bosques de azinheira sobrevivem em áreas de fogos frequentes?

Apesar da azinheira (Quercus rotundifolia) ser uma árvore muito comum em Portugal os bosques desta espécie são raros no nosso país. Muitos dos actuais azinhais ocorrem em áreas de elevada ou muito elevada frequência de fogos florestais. Foi recentemente observado que determinados fogos se extinguem ao contacto com azinhais

Survival of holm oak woodlands in fire prone landscapes in Northeastern Portugal

It has been observed that holm oak (Quercus rotundifo/ia) woodlands survive wildfires in Northeastern Portugal which sell-extinguish in contact with these woodlands. The mechanisms underlying this phenomenon are unknown. As part 01 an effort to understand the role of holm oak woodlands in landscape fire hazard, we have tested the hypothesis that holm oak woodlands are lire resistant and that this is due to fire behavior modification at the shrubland-woodland interface

Phenomenological Understanding of Hematite Photoanode Performance

The effect of the structural and electronic properties of hematite photoanodes on the charge carrier dynamics was investigated by photoelectrochemistry and transient absorption spectroscopy (TAS). Hematite photoelectrodes were prepared by spray pyrolysis and hydrothermal methods for obtaining films with different thicknesses, morphologies, doping agents, and surface treatments. TAS analyses were performed using standalone photoelectrodes, a three-electrode configuration and in operando. TAS studies revealed that there is a significant electron-hole recombination within the first few hundred picoseconds and smaller amplitude of longer-lived charge carriers, which are responsible for the generated photocurrent observed in photoelectrochemical measurements. The best performing photoelectrodes are Sn-doped hematite thin film annealed at 800 °C and coated with IrO2/RuO2 co-catalyst and the Ti-doped hematite nanowires. The effect of surface treatments, i.e., high-temperature annealing responsible for Sn intrinsic doping and co-catalyst coating, on the electron-hole recombination dynamics is negligible at the picosecond time scale. The TAS studies showed a slower electron-hole recombination after Ti incorporation, increased electron density, and enlarged surface area

A 2.4-GHz low-power/low-voltage wireless plug-and-play module for EEG applications

This paper presents a plug-and-play module for wireless electroencephalogram (EEG) applications. The wireless module is composed by an electrode, processing electronics, a radio-frequency (RF) transceiver, and an associated antenna. The RF transceiver was fabricated in the UMC RF 0.18 mum CMOS process, and operates in the 2.4-GHz ISM band. The receiver has a sensitivity of -60 dBm and a power consumption of 6.3 mW from a 1.8 V supply. The transmitter delivers an output power of 0 dBm with a power consumption of 11.2 mW, for a range of 10 m. It is also presented the electrical performance and comparison between different electrodes for EEG applications, namely sputtered titanium nitride (TiN) electrodes, standard sintered silver/silver chloride (Ag/AgCl) ring electrodes and sputtered iridium oxide (IrO2) electrodes. The experimental results show a better performance of the sputtered IrO2 electrodes compared with the standard sintered Ag/AgCl ring electrodes. These results promise a new opportunity for the application of a dry IrO2 electrodes in wireless modules for using in a wearable EEG braincap. These wireless EEG modules will allow patients to wear a brain cap and maintain their mobility, while simultaneously having their electrical brain activity monitored

A soil classification for seismic hazard assessment and mitigation of the Algarve

The Algarve province of Portugal is located near the E-W Eurasia-Africa plate boundary. It is characterized by a moderate seismicity, with some important historical earthquakes causing important damage and economical losses. Not only has it suffered the effects of large plate boundary events but also the impact of local onshore moderate-sized earthquake sources. The seismic hazard evaluation and mitigation of the area is therefore of great importance to the local populations and the large number of tourists that frequent the region. This paper focuses the evaluation of the most interesting and useful geotechnical near-surface parameters and a soil classification. The classification based upon the European Code 8 for civil engineering and SPT bedrock data, was carried out for land use planning and design of critical facilities. P-wave and S-wave seismic velocities were obtained through the acquisition, processing and interpretation refraction profiles. Hundreds of SPT parameters from available boreholes drilled for engineering and water supply were used and subsoil classification based on geophysical and geotechnical parameters is presented. Other parameters, such as Vp/Vs ratios and the Poisson coefficient were estimated and were computed to provide information for future site effect studies. The experimental procedure tested here is relatively fast, economical and easy to perform and can be useful to estimate soil microzoning and seismic hazard mapping in the absence of local earthquake records

A strategy to improve engineering teaching process based on an e-learning approach

Abstract-This paper presents a project which was realized with the objective of implementing an alternative solution to teaching methods, solution which involves the assistance of computers working as pedagogical tools complementary to the traditional methods that are used in the teaching of subjects such as Mathematics, Electrics and Electronics. Besides the background that has motivated the realization of this project, this paper presents not only the strategies, principles and philosophy which were defined for the courses content but also the way in which a solution was implemented, as well as the strategy expected to be carried out to test the solution and evaluate the results of these tests. In addition, it will also explore the alterations that this type of strategy may cause in the roles traditionally attributed to teachers and students, and the effect that these changes bring about in the teacher-student relationship. Finally, this paper also contains a brief presentation of the organizational structure of the solution, the phases and main tasks that this project involved, other phases expected to be carried out in the future, as well as its conclusions. I. KEYWORDS Education, e-learning, computer supported learning, web-based, mathematics learning, electronics engineering learning, electrical engineering learning II. PROJECT BACKGROUND The past years, in Portugal, the teaching of subjects such as Mathematics, Electronics and Electrics at College level has been characterized by a high difficulty of attracting new students, by problems in the learning process, a great lack of motivation and drop outs. In the heart of this situation, which has been worsening significantly over time, are the conjectural factors which go hand in hand with the structural factors. Among the conjectural factors, there is the thought that the study of these subjects is "out of fashion" and hardersince they usually demand a bigger effort and dedication from the students -than other taught subjects. Among the structural factors, is the lower will of students to study scientific and technological subjects as well as the little status recognition of these technological professions by society. Due to these problems it is urgent to find alternatives and complementary solutions to the traditional teaching methods in order to change the existing situation. The solution here presented includes the assistance of computers in the teaching process. III. PROJECT OBJECTIVES The objective of this project was to build a solution based on education assisted by computers to learn the basic subjects of technological degrees such as Mathematics, Electronics and Electrics. The goal of the implementation of this solution didn't consist in replacing the traditional teaching methods but in creating a complementary alternative meant to contribute to the liking, the interest and motivation of the students for this kind of subjects and therefore, to improve their learning ability. In the same manner, the objective of this project didn't consist in adopting conservative and simple strategies to transpose old teaching methods or learning contents into a new support system but to implement a really innovative solution in the pedagogy and the adopted solutions. IV. STRATEGY IMPLEMENTATION After defining the objectives, it became fundamental to define the orientation of the strategy lines according to the implementation of the given solution. This is why the following points were identified as critical factors in order for the solution to succeed: 1. To explain the taught subjects using a language which is simple, clear, direct, adequate and attractive to the public to whom the courses are addressed. 2. To put an emphasis on demonstrating and assisting each theoretical concept with a practical application. 24 hours a day, 7 days a week and the studying process needs to be possible from school, home, work or other places. 6. To make available auto-evaluation methods. Through the existence of components such as games, challenges, and entertaining activities students should be able to evaluate the progress of their knowledge. 7. To allow, in case of failure, the repetition of the studying process as well as the practise, and yet to Instead of playing the role of distributor of knowledge and information commonly attributed to the teacher in a traditional classroom setting, the role of the teacher will now be primarily concentrated on: 1. The coordination, facilitation, dynamization and motivation of each studen

A recursive process related to a partizan variation of wythoff

Wythoff queens is a classical combinatorial game related to very interesting mathematical results. An amazing one is the fact that the P-positions are given by $(\lfloor \phi n, \phi^2 n \rfloor)$ and $(\lfloor \phi^2 n, \phi n \rfloor)$ where $\phi = \frac{1 + \sqrt{5}}{2}$. In this paper, we analyze a different version where one player (Left) plays with a chess bishop and the other (Right) plays with a chess knight. The new game (call it chessfights) lacks a Beatty sequence structure in the P-positions as in wythoff queens. However, it is possible to formulate and prove some general results of a general recursive law which is a particular case of a partizan subtraction game

Tectonic and neotectonic implications of a new basement map of the Lower Tagus Valley, Portugal

In this paper we present a new basement (defined here as Paleozoic, Precambrian and Mesozoic igneous rocks) map of the Lower Tagus Valley area. This map is a contribution to the understanding of the structural evolution of the top of the basement in the Lower Tagus Valley area during the Mesozoic and Cenozoic Eras. The map was produced using aeromagnetic, well, seismic reflection and geological outcrop data. It shows unprecedented details of the geometry of the basement rock's surface with higher resolution and covers a larger area than the previous basement map of the study area. In spite of an estimated average error of 200 m in depth and an horizontal resolution of 4 km, our map not only reproduces with accuracy several well known basement structures but it also emphasizes previously unknown features. Major basement faults were inferred from large depth variations at the top of the basement, magnetic 2D Euler deconvolution and horizontal gradient analysis and are compatible with surface geological structures, well data and hydrogeological information. Implications to the geodynamic evolution of the SW European Variscides and consequences to Meso-Cenozoic tectonics are discussed. The correlation of the basement structures with instrumental seismicity is carried out and their neotectonic activity is discussed on the basis of existing geological outcrop data