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Liordos V.,University of Edinburgh | Liordos V.,Eastern Macedonia and Thrace Institute of Technology | Lauder A.W.,Loch Leven Laboratory
Waterbirds | Year: 2015

Nest success and nest-site characteristics of the Tufted Duck (Aythya fuligula) were studied during the 1996 breeding season at Loch Leven, Scotland. Approximately 463 ± 47 Tufted Duck pairs nested in association with 6,674 ± 805 Black-headed Gull pairs (Larus ridibundus) on St. Serf's Island. Tufted Ducks had an apparent nest success rate of 79.5% (Range: 65.8%83.6%; n = 73). Multiple logistic regression was used to test the hypothesis that nest-site characteristics, such as distance to colony edge, overhead and vertical nest cover and distance to nearest Tufted Duck or Black-headed Gull nest, affect nest success. By using only the Tufted Duck nests with a known fate (n = 60), distance to the colony edge was identified as the primary predictor of nest success (P = 0.004), with successful nests (31.60 ± 1.71 m) located farther from the colony edge than those that failed (18.75 ± 2.61 m). Results support the central-periphery nest distribution model which suggests that nests located in the center of a colony, particularly in homogeneous habitats, are less accessible to predators and have greater reproductive success. © 2015, BioOne. All rights reserved. Source


Fantidis J.G.,Eastern Macedonia and Thrace Institute of Technology
International Journal of Radiation Research | Year: 2015

Background: Monte Carlo simulations play a vital role in the calculation of the necessary shielding both for neutrons and photons. Advanced and simple shielding materials against neutron and gamma rays were compared by simulation using the MCNB4B Monte Carlo code. The simulations were carried out for the three common neutron sources, namely the 252Cf, the 241Am/Be and the DD neutron generator which are suitable for transportable facilities. Materials and Methods: The source has been simulated as sphere with 3 cm diameter while the necessary shielding is designed in the form of a sphere around the neutron source. The materials considered were chosen according to the EU Directive 2002/95/EC, hence excluding lead and cadmium. Results: In the case of DD neutron generator the thickness, the weight and the volume of the shield can decrease up to 41.3, 44, and 78.4% correspondingly. With regard to the 252Cf neutron source the use of advanced shielding materials can reduce the corresponding parameters up to 32.7, 40.7, and 68.4% respectively. As regards the 241Am/Be neutron source, based on advanced shielding materials the thickness, the mass and the volume of the shield can decrease by 33.8, 49.5, and 70% respectively. Conclusion: The obtained results showed that the use of advanced shielding materials has led to reduce greatly the weight and the volume of the necessary shield. Source


Favvas E.P.,Greek National Center For Scientific Research | Favvas E.P.,Eastern Macedonia and Thrace Institute of Technology
Separation and Purification Technology | Year: 2014

Two asymmetric carbon hollow fiber membranes were prepared and tested for CO2 permeance from low, atmospheric, to high pressures up to ∼55 bar. Both membranes were produced via pyrolysis of polyimide hollow fiber membranes at 1050 °C, the one in inert environment, while the other was activated with CO2 at the higher pyrolysis temperature. The carbon dioxide was chosen for the permeance performance of the studied membranes. A maximum in the curve of permeance versus equilibrium pressure is observed at 32 bar for both studied carbon hollow fiber membranes. This phenomenon has close analogy to the case of mesoporous membranes. The result shows that the CO 2 provides a maximum in the permeance values. This weakens considerably as the membrane ultra-microporosity is increased. The high pressure gas permeance study may be potentially useful for the identification of the optimal pressure and temperature conditions for efficient gas separations. © 2014 Elsevier B.V. All rights reserved. Source


Radulescu M.,University of Pitesti | Banica L.,University of Pitesti | Polychronidou P.,Eastern Macedonia and Thrace Institute of Technology
Economic Computation and Economic Cybernetics Studies and Research | Year: 2015

The Greek banks have to limit their operations in the Southern and Eastern Europe, because the European Commission requested to stop transfer capital to their subsidiaries in this region. This means that the Greek banks have to sell some of their subsidiaries in the region, especially the non-profitable ones. The aim of this paper is to forecast the profitability ratios of the Greek capital owned banks activating in Romania for 2013-2014 to see what would be their best option regarding these subsidiaries in Romania against the other subsidiaries of the Greek banking groups in the region. In the strategy of a multi-national bank, two categories of macroeconomic indicators forecasts are important: the ones in the countries where it has subsidiaries, and it’s own forecasts, in order to monitor the future evolution of their business and financial stability. In this paper, the authors focus on forecasting the performance indicators of four Greek banks and their Romanian branches, based on artificial neural networks (ANN). The study uses various implementations of the neural network algorithm offered by GMDH Shell software and the balance sheet of the four Greek banks and their Romanian branches, during 2006-2012, in order to obtain a short term forecasting of performance indicators. © 2015,Academy of Economic Studies, All right reserved. Source


Liordos V.,Hellenic Forest Service | Liordos V.,Eastern Macedonia and Thrace Institute of Technology
Zoology and Ecology | Year: 2014

Knowledge of hunters' behaviour is critical for the proper management of hunting. The preferences and sociodemographic characteristics of a Greek hunting community, the Megara Hunting Club, were therefore investigated through a questionnaire survey. Club members were mostly less than 50 years old with a family, mainly self-employed, farmers or private employees of secondary education and mostly having medium or higher income. All income classes preferred local over national licences, although the lower class did so in higher proportions. Megara hunters pursued the local small game, for which they also searched elsewhere. They were strongly attached to hunting as a sport, except for the poorest who hunted for subsistence. Furthermore, local hunters spent annually on average 58.3 days and € 1764.6, with the middle-aged, highly educated or wealthier hunters being the most dedicated to hunting in terms of both time and money. Considering the ongoing Greek debt crisis, an increase in the demand of local game and a shift towards subsistence hunting is predicted. Research offered important new insights for the practice of hunting and could be used as an aid for the design and application of informed policy and management plans in Greece and also in other comparable countries. © 2014 Nature Research Centre. Source

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