The Alexander Technological Educational Institute of Thessaloniki , is a higher education public institute, part of the Greek tertiary education system, specialized on applied science. The institute has three campuses. The main campus is located 15 km outside the city of Thessaloniki in Sindos, the second campus is in the nearby city of Kilkis and the last campus is in Nea Moudania. Wikipedia.
Aristotle University of Thessaloniki, Alexander Technological Educational Institute of Thessaloniki, Voltampere Energy LTD, Mademlis and Kioskeridis | Date: 2014-05-28
A method for efficiency optimization of a wind generator by controlling the squirrel cage induction generator is proposed. The method achieves simultaneously maximum efficiency of the wind turbine (wind mill) and maximum efficiency of the electric generator through the minimization of its electric loss. Additionally, expansion of the exploitable wind speed region is accomplished through the reduction of the cut-in speed at which the wind system starts to provide power to the grid. The method is implemented by appropriately controlling the power rectifier and without requiring the measurement of the wind speed. Input to the control scheme is the rotational speed of the electric generator. The control scheme comprises two controllers that, for any wind speed, provide the optimal reference field and torque stator current components of the squirrel cage induction generator. The two current components are determined through optimal conditions. The main advantages of the presented control scheme are the quick response so as it can follow the fast changes of the wind speed and also the simple implementation and the easy installation.
Agency: European Commission | Branch: H2020 | Program: RIA | Phase: BG-10-2014 | Award Amount: 5.21M | Year: 2015
SUCCESS is bringing together an integrated team of scientists from all fields of fisheries and aquaculture science with industry partners and key stakeholders to work on solutions which shall improve the competitiveness of the European fisheries and aquaculture sector. The supply-side of seafood markets is limited from both sea fisheries and aquaculture. At the same time demand for seafood products is increasing. In a globalised economy, the conjunction of these two trends should generate high opportunities for any seafood production activity. However, both fisheries and aquaculture companies are facing key challenges, which currently hinder them reaping the full benefits of seafood markets expansion, and even question their sustainability. As a whole, the EU fisheries sector remains at low levels of profitability and sustainability. The SUCCESS project will examine two strategies to improve the competitiveness of the sector: (i) increasing demand for EU seafood products, especially improving the awareness of the advantages of European production (including sustainability requirements and adjustment to market evolution); and (ii) cost reduction in certain production segments. For both strategies development on world markets as well as consumer preferences and awareness will be analysed. Additionally, SUCCESS will explore the different sectors along the value chain (from fisheries and aquaculture producers via processing companies, wholesalers, retailers to direct marketing to mobile fishmongers and restaurants) and their potential for improvements in competitiveness. These analyses also include long term predictions about the viability of certain production systems and will be considered in specific case studies on for example mussel production, shrimp fisheries, whitefish, traditional pond aquaculture and new aquaculture production systems.
Rigas P.G.,Alexander Technological Educational Institute of Thessaloniki
Analytical and Bioanalytical Chemistry | Year: 2013
Amino acid analysis (AAA) has always presented an analytical challenge in terms of sample preparation, separation, and detection. Because of the vast number of amino acids, various separation methods have been applied taking into consideration the large differences in their chemical structures, which span from nonpolar to highly polar side chains. Numerous separation methods have been developed in the past 60 years, and impressive achievements have been made in the fields of separation, derivatization, and detection of amino acids (AAs). Among the separation methods, liquid chromatography (LC) prevailed in the AAA field using either pre-column or post-column labeling techniques in order to improve either separation of AAs or selectivity and sensitivity of AAA. Of the two approaches, the post-column technique is a more rugged and reproducible method and provides excellent AAs separation relatively free from interferences. This review considers current separations combined with post-column labeling techniques for AAA, comparison with the pre-column methods, and the strategies used to develop effective post-column methodology. The focus of the article is on LC methods coupled with post-column labeling techniques and studying the reactions to achieve optimum post-column derivatization (PCD) conditions in order to increase sensitivity and selectivity using various types of detectors (UV-Vis, fluorescence, electrochemical etc.) and illustrating the versatility of the PCD methods for practical analysis. [Figure not available: see fulltext.] © 2013 Springer-Verlag Berlin Heidelberg.
Kambanaros M.,Alexander Technological Educational Institute of Thessaloniki
Aphasiology | Year: 2010
Background: Recently, verb-noun processing differences were reported in a group of late bilingual speakers with fluent, anomic aphasia in Greek (L1) as well as in English (L2) (Kambanaros & van Steenbrugge, 2006). The findings revealed that verb production was significantly more impaired than noun production in both languages during picture naming despite preserved comprehension of action and object names. Aims: The aim of this study is to investigate the total number (quantity) and the diversity (quality or different types) of verbs and nouns produced in conversational speech by the same group of bilingual anomic individuals with aphasia and compare the results to (i) those of the non-brain-injured control group and (ii) their action and object naming performances at the single word level, to determine if grammatical class impairments are also evident in spontaneous speech. Methods & Procedures: In order to examine the distribution and diversity of verbs and nouns in spontaneous speech, speech samples of 300 words were collected from the bilingual individuals with fluent aphasia and their controls in L1 and in L2 on two separate occasions, 1 week apart. In addition, two subtests from the Greek Object and Action Test (GOAT: Kambanaros, 2003), the object and action naming subtests, were presented on two separate occasions, 1 week apart, to both groups of bilingual participants in L1 and L2 (cf. Kambanaros & van Steenbrugge, 2006). Outcomes & Results: Late bilingual participants with anomia showed no difficulties retrieving verbs in spontaneous speech in L1 or L2 despite a significant verb deficit in both languages on action naming tasks. However the bilingual group had significant difficulties in relation to noun production in spontaneous speech in L1 and L2. Conclusions: Picture naming remains the standard of word retrieval ability in aphasia. However, object and action naming scores can underestimate and/or overestimate word retrieval performance for nouns and verbs in connected speech. © 2010 Psychology Press.
Panagopoulos G.,Alexander Technological Educational Institute of Thessaloniki
Environmental Earth Sciences | Year: 2012
Karst aquifers can have a complex flow as a result of the formation of large conduits from dissolution features. As a result, a three-dimensional finite-difference groundwater flow model (equivalent porous media) may not apply as the dual porosity nature of karst features and the effects of turbulent flow cannot be directly simulated. Statistical analysis of karst hydrographs of the Trifilia aquifer in Greece showed the existence of a slightly karstified mass with high primary porosity that regulates the flow. An equivalent porous media model was developed to simulate the Trifilia karst aquifer using MODFLOW. Steady state and transient state calibration gave encouraging results for the equivalent porous media approach, which does not consider pipe flow or turbulence. Detailed hydrogeological research conducted in the area helped define the aquifer hydraulic conductivity zones and extent; and flux to/from the aquifer. Only hydraulic conductivity and specific yield were adjusted during calibration, as the flux to/from the system was considered known and applied as boundary conditions. Small mean absolute and RMS piezometric head error of the model under both steady and transient state conditions were achieved. © 2012 Springer-Verlag.
Rigas P.G.,Alexander Technological Educational Institute of Thessaloniki
Instrumentation Science and Technology | Year: 2012
Amino acid analysis (AAA) is widely used for determining the composition of proteins and their concentration in foods, biological fluids, and tissues. Because of the vast number of amino acids, the chromatographic techniques provide separations of them based either on the charge or on hydrophobicity differences. Several chromatographic techniques have been applied for this purpose, with the method of choice being ion-exchange chromatography followed by post-column derivatization, as a more rugged and reproducible method provides excellent amino acid separation with relative freedom from interferences. This review considers recent relative reviews, current separation techniques, the most popular post-column reactions for amino acid analysis, comparison with the pre-column methods, the strategies used to develop effective post-column methodology, instrumentation technology, and applications in food and clinical analysis. The focus of the article is on liquid chromatographic methods coupled with post-column derivatization in order to increase sensitivity and selectivity, illustrating the versatility of the post-column derivatization (PCD) instrumentation for practical analysis. Copyright © Taylor & Francis Group, LLC.
Kazafeos K.,Alexander Technological Educational Institute of Thessaloniki
Diabetes Research and Clinical Practice | Year: 2011
The term incretin effect was used to describe the fact that oral glucose load produces a greater insulin response than that of an isoglycemic intravenous glucose infusion. This difference has been attributed to gastrointestinal peptides GLP-1 and GIP. Since incretin effect is reduced in subjects with type 2 diabetes, despite GLP-1 activity preservation, two forms of incretin-based treatment have emerged: GLP-1R agonists, administered subcutaneously and DPP-4 inhibitors, administered orally. There is a great interest whether incretin-based treatment will be associated with sustained long-term control and improvement in β-cell function. The observation that GLP-1R agonists improve myocardial function and survival of cardiomyocytes highlights the need for further studies. Incretin-based therapies offer a new option and show great promise for the treatment of type 2 diabetes. © 2011 Elsevier Ireland Ltd.
Anagnostopoulos C.A.,Alexander Technological Educational Institute of Thessaloniki
Construction and Building Materials | Year: 2014
The use of superplasticisers in microfine or regular cement-based grouts has become of vital importance in advanced professional grouting practices. These superplasticisers play an important role in the production of more durable grouts with improved rheological characteristics. This report presents a laboratory study of the effects of a new-generation polycarboxylate superplasticiser (PCE) on the rheological properties, mechanical strength, final setting time and bleeding of cement grouts in comparison to that of a polynaphthalene superplasticiser (SNF). The experiments were conducted using different superplasticiser dosages with cement grouts proportioned with a water to cement ratio (w/c) of 0.33, 0.4 or 0.5. The results showed that grouts with PCE had higher viscosity, slightly increased bleeding and longer setting times compared with the SNF admixture. However, the PCE improved the final strength, especially for grouts with a w/c ratio of 0.4 and 0.5, and decreased the yield stress. © 2013 Elsevier Ltd. All rights reserved.
Tsarouhas P.H.,Alexander Technological Educational Institute of Thessaloniki
International Journal of Production Research | Year: 2013
Overall equipment effectiveness (OEE) is a well-accepted measure of performance in industry. This study investigates the relationship between the factory management and the operation of the limoncello production line. The analysis of failure and repair data of the line over a period of 8 months was carried out. Descriptive statistics at machine and at line level were computed. In addition, the components availability (A), performance efficiency (PE), and quality rate (QR) of the OEE were calculated. Failure and repair data analysis identify the critical points of the production process that need immediate action to improve the operation of the line. Results show that the components PE and QR should be improved immediately to optimise the productivity and the efficiency of the line. It can also be utilised in the beverage industry sector by the machinery manufacturers and the manufacturers of bottled products to improve the design and operation management of the bottling production lines. © 2013 Taylor & Francis.
Karipidis P.I.,Alexander Technological Educational Institute of Thessaloniki
International Journal of Production Economics | Year: 2011
After a literature review on the economics of quality, we combine the value creation logic with the hedonic price function to analyze dimensions of design quality in enterprises. Viewing the quality-based organization as a collection of processes generating quality attributes and characteristics that constitute a solution for customers, we estimate market value as a measure of process economic performance based on objectively measured real economic data. The model can help to identify the relationship between design quality and market evaluations and to manage the quality of product and service at supply chain level. © 2010 Elsevier B.V. All rights reserved.