Institution
National Technical University of Athens
Education•Athens, Attiki, Greece•
About: National Technical University of Athens is a education organization based out in Athens, Attiki, Greece. It is known for research contribution in the topics: Large Hadron Collider & Nonlinear system. The organization has 13445 authors who have published 31259 publications receiving 723504 citations. The organization is also known as: Athens Polytechnic & NTUA.
Topics: Large Hadron Collider, Nonlinear system, Context (language use), Finite element method, Computer science
Papers published on a yearly basis
Papers
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University of Duisburg-Essen1, University of Stirling2, Aarhus University3, Middle East Technical University4, University of Lisbon5, Laval University6, Norwegian Institute for Water Research7, Estonian University of Life Sciences8, Lancaster University9, Leibniz Association10, Technical University of Berlin11, University of Ljubljana12, Helmholtz Centre for Environmental Research - UFZ13, University of Natural Resources and Life Sciences, Vienna14, Cardiff University15, University of Barcelona16, Finnish Environment Institute17, DHI Water & Environment18, National Technical University of Athens19, Radboud University Nijmegen20, Free University of Berlin21, University of Koblenz and Landau22
TL;DR: A cross-scale analysis of paired-stressor effects on biological variables of European freshwater ecosystems shows that in 39% of cases, significant effects were limited to single stressors, with nutrient enrichment being the most important of these in lakes.
Abstract: Climate and land-use change drive a suite of stressors that shape ecosystems and interact to yield complex ecological responses (that is, additive, antagonistic and synergistic effects). We know little about the spatial scales relevant for the outcomes of such interactions and little about effect sizes. These knowledge gaps need to be filled to underpin future land management decisions or climate mitigation interventions for protecting and restoring freshwater ecosystems. This study combines data across scales from 33 mesocosm experiments with those from 14 river basins and 22 cross-basin studies in Europe, producing 174 combinations of paired-stressor effects on a biological response variable. Generalized linear models showed that only one of the two stressors had a significant effect in 39% of the analysed cases, 28% of the paired-stressor combinations resulted in additive effects and 33% resulted in interactive (antagonistic, synergistic, opposing or reversal) effects. For lakes, the frequencies of additive and interactive effects were similar for all spatial scales addressed, while for rivers these frequencies increased with scale. Nutrient enrichment was the overriding stressor for lakes, with effects generally exceeding those of secondary stressors. For rivers, the effects of nutrient enrichment were dependent on the specific stressor combination and biological response variable. These results vindicate the traditional focus of lake restoration and management on nutrient stress, while highlighting that river management requires more bespoke management solutions.
267 citations
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TL;DR: In this article, a systematic kinetic study of lascorbic acid loss of four green vegetables was conducted in the temperature range of freezing storage, and the temperature-dependence of vitamin C loss in the −3 to −20 °C range was adequately modelled by the Arrhenius equation and activation energy ranged from 98 to 112 kJ/mol.
267 citations
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TL;DR: In this article, the effect of the method used for drying on colour of apple, banana, potato and carrot was investigated for five different methods of drying: conventional, vacuum, microwave, freeze and osmotic drying.
Abstract: Summary We tested the hypothesis that an optimum method of drying fruit could be designed. The effect of the method used for drying on colour of apple, banana, potato and carrot was investigated for five different methods of drying: conventional, vacuum, microwave, freeze and osmotic drying. Colour characteristics were studied by measuring lightness (L), redness (a) and yellowness (b) using a Hunter Lab chromatometer. The method used to dry the material was found to significantly affect the three colour parameters. The changes in redness (a) and yellowness (b) were found to follow a first order kinetic model. Air-, vacuum- and microwave-dried materials caused extensive browning in the fruits and vegetables, this was manifested by a significant drop of the L parameter and an increase of the a and b parameters. Osmotically pretreated samples did not brown as much as the untreated samples and the value for lightness (L) decreased only slightly while a and b increased slightly. Freeze drying seems to prevent colour changes, resulting in products with improved colour characteristics.
267 citations
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23 Jun 2014TL;DR: A simple vector quantizer is presented that combines low distortion with fast search and applies it to approximate nearest neighbor (ANN) search in high dimensional spaces.
Abstract: We present a simple vector quantizer that combines low distortion with fast search and apply it to approximate nearest neighbor (ANN) search in high dimensional spaces. Leveraging the very same data structure that is used to provide non-exhaustive search, i.e., inverted lists or a multi-index, the idea is to locally optimize an individual product quantizer (PQ) per cell and use it to encode residuals. Local optimization is over rotation and space decomposition, interestingly, we apply a parametric solution that assumes a normal distribution and is extremely fast to train. With a reasonable space and time overhead that is constant in the data size, we set a new state-of-the-art on several public datasets, including a billion-scale one.
267 citations
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TL;DR: In this paper, the authors used the hydrologic evaluation of landfill performance (HELP) model for the determination of the yearly leakage from the base of the landfill after the final capping.
Abstract: Characterisation of the leachate originating from the Ano Liosia landfill (situated in Attica region, Greece) as well as assessment on the quality of the local aquifer were carried out. The experimental results showed that most of the parameters examined in the leachate samples such as colour, conductivity, TS, COD, NH3–N, PO4–P, SO42−, Cl−, K+, Fe and Pb were found in high levels. The organic load was quite high since the COD concentrations were in the range of 3250–6125 mg L−1. In addition, the low BOD/COD ratio (0.096–0.195), confirmed that the majority of this organic matter is not easily biodegradable. The groundwater near the landfill site was characterised as not potable and not suitable for irrigation water, since most of the physical and chemical parameters examined – such as colour, conductivity, DS, hardness, Cl−, NH3–N, COD, K+, Na+, Ca2+, Fe, Ni and Pb exceeded the permissible limits given by EE, EPA and the Greek Ministry of Agriculture. Furthermore, this study presents the application of the hydrologic evaluation of landfill performance (HELP) model for the determination of the yearly leakage from the base of the landfill after the final capping.
267 citations
Authors
Showing all 13584 results
Name | H-index | Papers | Citations |
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J. S. Lange | 160 | 2083 | 145919 |
Nicholas A. Peppas | 141 | 825 | 90533 |
Claude Amsler | 138 | 1454 | 135063 |
Y. B. Hsiung | 138 | 1258 | 94278 |
M. I. Martínez | 134 | 1251 | 79885 |
Elliott Cheu | 133 | 1219 | 91305 |
Evangelos Gazis | 131 | 1147 | 84159 |
Stavros Maltezos | 129 | 943 | 79654 |
Serkant Ali Cetin | 129 | 1369 | 85175 |
Matteo Cavalli-Sforza | 129 | 1273 | 89442 |
Stefano Colafranceschi | 129 | 1103 | 79174 |
Konstantinos Nikolopoulos | 128 | 931 | 75907 |
Ilya Korolkov | 128 | 884 | 75312 |
Martine Bosman | 128 | 942 | 73848 |
Sotirios Vlachos | 128 | 789 | 77317 |