TIDAL ENERGY: THE CASE OF EURIPUS’ STRAITS

The tidal energy potential of low current tidal and marine currents is investigated in this work. Existing data on the current velocity and sea level at the Euripus’ strait in Evia, Greece, is used to compute the energy yield based on contemporary turbine designs. Requirements, limitations and opportunities concerning the exploitation of low velocity tidal streams are discussed. The exploitation of tidal energy technology in conjunction with RES microgrids is proposed for coastal areas with abundance of sun and wind such as the Mediterranean islands

TIDAL ENERGY: THE CASE OF EURIPUS’ STRAITS

The tidal energy potential of low current tidal and marine currents is investigated in this work. Existing data on the current velocity and sea level at the Euripus’ strait in Evia, Greece, is used to compute the energy yield based on contemporary turbine designs. Requirements, limitations and opportunities concerning the exploitation of low velocity tidal streams are discussed. The exploitation of tidal energy technology in conjunction with RES microgrids is proposed for coastal areas with abundance of sun and wind such as the Mediterranean islands

GAMIFYING ENERGY USER PROFILES

Smartege is an educational application which aims in educating users in the basics of electrical energy consumption and production and engage them in energy saving behavior, techniques and technologies. This is accomplished through the virtual, and eventually actual, management of residential and office buildings equipped with virtual devices and renewable energy sources, with energy specifications borrowed from actual commercial devices, towards the ultimate target of transforming the buildings into net Zero Energy Buildings. Ultimately, Smartege is a gamified application targeting the behavior modification of the users. Its content development follows the persuasive model and uses cognitive learning for the educational component and game mechanics for user motivation and triggering

GAMIFYING ENERGY USER PROFILES

Smartege is an educational application which aims in educating users in the basics of electrical energy consumption and production and engage them in energy saving behavior, techniques and technologies. This is accomplished through the virtual, and eventually actual, management of residential and office buildings equipped with virtual devices and renewable energy sources, with energy specifications borrowed from actual commercial devices, towards the ultimate target of transforming the buildings into net Zero Energy Buildings. Ultimately, Smartege is a gamified application targeting the behavior modification of the users. Its content development follows the persuasive model and uses cognitive learning for the educational component and game mechanics for user motivation and triggering

Hydrotherapy (Project Hydriades)

Natural resources are being used for the maintenance of health. According to the Law 3498/2006 of the Greek Parliament the natural health spas must be validated for their therapeutic properties. The Association of Municipalities and Communities of Health Springs of Greece signed a contract with the Research Committee of the Aristotle University of Thessaloniki, Greece, in order to conduct the research programme: ‘Study for the documentation of the therapeutic properties of the thermomineral waters’. The main aim of the project is: (1) the study of biological and therapeutic parameters of the natural health sources, (2) the identification of the indications and contraindications of hydrotherapy. Aims parallel to the main ones have been also set

THEORETICAL STUDY OF SMALL GAPS ELECTRICAL DISCHARGE BEHAVIOUR

THEORETICAL PREDICTIONS ARE GIVEN OF THE DEVELOPMENT OF THE BREAKDOWN MECHANISMS AND OF THE FORMATION OF CATHODE AND ANODE REGIONS IN SMALL GAPS AT HIGH (760 TORRS) AND LOW (50 TORRS) PRESSURE. THE APPLIED FIELD IS DETERMINED BY THE ELECTRODE GEOMETRY AND THE EVOLUTION OF POSITIVE AND NEGATIVE IONS AND ELECTRONS ISDESCRIBED BY ONE-DIMENSIONAL CONTINUITY EQUATION IN CONJUCTION WITH THE POISSON'S EQUATIONS WHICH ARE RESOLVED BY AN ACCURATE NUMERICAL METHOD. THE EFFECTS OF IONIZATION, RECOMBINATION, ATTACHMENT AND ION SECONDARY-ELECTRON EMISSION FROM THE CATHODE ARE ALL INCLUDED. THE RESULTS OBTAINED AGREE SATISFACTORILY WITH EXPERIMENTAL VALUES. THE MAIN MECHANISM OF BREAKDOWN IS THAT OF THE STREAMER AND THE FEATURES OF HIS FORMATION CAN BE UNDERSTOOD BY NOTING THAT ANY CHANGE IN THE ELECTRIC FIELD IN N2 AND IN ATMOSPHERIC AIR CAUSES ABRUPT CHANGES IN THE ELECTRON DENSITY DUE TO EITHER STRONG NET ATTACHMENT OR STRONG NETIONIZATION WHICH BALANCE AT THE CRITICAL ELECTRIC FIELD . IN THE STREAMER HEAD THE NET CHARGE ENHANCES THE FIELD AHEAD OF THE STREAMER AND DEPRESS THE FIELD BEHIND. WHEN THESTREAMER HEAD APPROACHES THE CAFHODE A CAFHODE FALL REGION IS FORMED IMMEDIATELY ADJACENT TO THE CATHODE FOLLOWED BY A DISTURBANCE IN THE ANODE FALL REGION ESPECIALLY SIGNIFICANT FOR THE ELECTRONEGATIVE GASES. THE LATTER PROPAGATES TOWARDS THE CATHODE WITH A SPEED LESS THAN THAT OF STEAMER PROPAGATION. THUS A SECONDARY STREAMER IS FORMATED.ΑΝΑΠΤΥΣΣΟΝΤΑΙ ΘΕΩΡΗΤΙΚΕΣ ΑΠΟΨΕΙΣ ΣΧΕΤΙΚΑ ΜΕ ΤΟΥΣ ΜΗΧΑΝΙΣΜΟΥΣ ΗΛΕΚΤΡΙΚΗΣ ΔΙΑΣΠΑΣΗΣ ΜΙΚΡΩΝ ΔΙΑΚΕΝΩΝ ΚΑΙ ΜΕ ΤΟΝ ΣΧΗΜΑΤΙΣΜΟ ΤΗΣ ΚΑΘΟΔΙΚΗΣ ΚΑΙ ΑΝΟΔΙΚΗΣ ΠΕΡΙΟΧΗΣ ΣΕΠΙΕΣΕΙΣ (750 ΚΑΙ 50 TORRS) ΣΕ ΑΤΜΟΣΦΑΙΡΙΚΟ ΑΕΡΑ ΚΑΙ Ν2. ΤΟ ΕΠΙΒΑΛΛΟΜΕΝΟ ΗΛΕΚΤΡΙΚΟ ΠΕΔΙΟ ΚΑΘΟΡΙΖΕΤΑΙ ΑΠΟ ΤΗΝ ΓΕΩΜΕΤΡΙΑ ΤΩΝ ΗΛΕΚΤΡΟΔΙΩΝ ΚΑΙ Η ΕΞΕΛΙΞΗ ΤΩΝ ΘΕΤΙΚΩΝ, ΑΡΝΗΤΙΚΩΝ ΙΟΝΤΩΝ ΚΑΙ ΗΛΕΚΤΡΟΝΙΩΝ ΠΕΡΙΓΡΑΦΕΤΑΙ ΑΠΟ ΤΙΣ ΜΟΝΟΔΙΑΣΤΑΤΕΣ ΕΞΙΣΩΣΕΙΣ ΣΥΝΕΧΕΙΑΣ ΣΕ ΣΥΝΔΥΑΣΜΟ ΜΕ ΤΗΝ ΕΞΙΣΩΣΗ ΤΟΥ POISSON ΟΙ ΟΠΟΙΕΣ ΕΠΙΛΥΟΝΤΑΙ ΜΕ ΜΙΑ ΚΑΤΑΛΛΗΛΗ ΑΡΙΘΜΗΤΙΚΗ ΜΕΘΟΔΟ. Ο ΙΟΝΙΣΜΟΣ, Η ΕΠΑΝΑΣΥΝΔΕΣΗ Η ΠΡΟΣΑΡΤΗΣΗ ΚΑΙ ΤΑ ΔΕΥΤΕΡΟΓΕΝΗ ΦΑΙΝΟΜΕΝΑ ΣΤΗΝ ΚΑΘΟΔΟ ΛΑΜΒΑΝΟΝΤΑΙ ΥΠΟΨΗ ΣΤΗΝ ΑΡΙΘΜΗΤΙΚΗ ΕΠΕΞΕΡΓΑΣΙΑ ΤΟΥ ΠΡΟΒΛΗΜΑΤΟΣ. ΤΑ ΠΑΡΑΛΗΦΘΕΝΤΑ ΑΠΟΤΕΛΕΣΜΑΤΑ ΣΥΜΦΩΝΟΥΝ ΙΚΑΝΟΠΟΙΗΤΙΚΑ ΜΕ ΑΥΤΑ ΤΩΝ ΠΕΙΡΑΜΑΤΩΝ. Ο ΚΥΡΙΟΣ ΜΗΧΑΝΙΣΜΟΣ ΔΙΑΣΠΑΣΗΣ ΕΙΝΑΙ ΑΥΤΟΣ ΤΟΥ STREAMER ΚΑΙ ΟΙ ΣΥΝΘΗΚΕΣ ΣΧΗΜΑΤΙΣΜΟΥ ΤΟΥ ΚΑΤΑΝΟΟΥΝΤΑΙ ΠΑΡΑΤΗΡΩΝΤΑΣ ΟΤΙ ΟΠΟΙΑΔΗΠΟΤΕ ΜΕΤΑΒΟΛΗ ΤΟΥ ΠΕΔΙΟΥ (Ν2 ΚΑΙ ΑΕΡΑ) ΠΡΟΚΑΛΕΙ ΑΠΟΤΟΜΕΣ ΜΕΤΑΒΟΛΕΣ ΣΤΗΝ ΗΛΕΚΤΡΟΝΙΚΗ ΠΥΚΝΟΤΗΤΑ ΟΙ ΟΠΟΙΕΣ ΟΦΕΙΛΟΝΤΑΙ ΕΙΤΕ ΣΤΟΝ ΕΝΤΟΝΟ ΙΟΝΙΣΜΟ ΕΙΤΕ ΣΤΗΝ ΕΝΤΟΝΗ ΠΡΟΣΑΡΤΗΣΗ, ΦΑΙΝΟΜΕΝΑ ΠΟΥ ΕΞΙΣΟΡΡΟΠΟΥΝΤΑΙ ΟΤΑΝ ΤΟ ΠΕΔΙΟ ΠΑΙΡΝΕΙ ΤΗΝ ΚΡΙΣΙΜΗ ΤΙΜΗ ΤΟΥ. ΣΤΗΝ ΚΕΦΑΛΗ ΤΟΥ STREAMER ΤΟ ΚΑΘΑΡΟ ΦΟΡΤΙΟ ΠΡΟΚΑΛΕΙ ΑΥΞΗΣΗ ΤΟΥ ΠΕΔΙΟΥ ΜΠΡΟΣΤΑ ΤΗΣ ΚΑΙ ΜΕΙΩΣΗ ΠΙΣΩ ΤΗΣ. ΟΤΑΝ Η ΚΕΦΑΛΗ ΤΟΥ STREAMER ΠΛΗΣΙΑΖΕΙ ΣΤΗΝ ΚΑΘΟΔΟ, ΣΧΗΜΑΤΙΖΕΤΑΙ ΑΜΕΣΑ Η ΚΑΘΟΔΙΚΗ ΠΕΡΙΟΧΗ Η ΟΠΟΙΑ ΑΚΟΛΟΥΘΕΙΤΑΙ ΑΠΟ ΜΙΑ ΔΙΑΤΑΡΑΧΗ ΤΗΣ ΑΝΟΔΙΚΗΣ ΠΕΡΙΟΧΗΣ. ΑΥΤΗ Η ΔΙΑΤΑΡΑΧΗ ΕΙΝΑΙ ΣΗΜΑΝΤΙΚΗ ΣΤΑ ΗΛΕΚΤΡΟΑΡΝΗΤΙΚΑ ΑΕΡΙΑ ΚΑΙ ΔΙΑΔΙΔΕΤΑΙ ΠΡΟΣ ΤΗΝ ΚΑΘΟΔΟ ΜΕ ΜΙΑ ΤΑΧΥΤΗΤΑ ΑΙΣΘΗΤΑ ΜΙΚΡΟΤΕΡΗ ΑΠ'ΑΥΤΗ ΤΟΥ STREAMER. ΜΕ ΑΥΤΟ ΤΟΝ ΤΡΟΠΟ ΣΧΗΜΑΤΙΣΘΗΚΕ Ο ΛΕΓΟΜΕΝΟΣ SECONDARY STREAMER

Impact of a Periodic Power Source on a RES Microgrid

The aim of this article is to highlight the impact of a periodic power source, such as a tidal turbine, on the operation and sizing of an autonomous hybrid microgrid with photovoltaic panels and storage. The technique of hill climbing (repeated local search) is used to find the optimum combination of Renewable Energy Sources (RES) and storage units with respect to the required capital cost for various load curves and weather conditions. To model the operation of the microgrid devices, analytical and phenomenological models, have been used, which take into account the specifications of actual commercial devices. Six different case studies are presented, with and without a tidal generator, which are based on six different sets of electrical consumption data corresponding to the Euripus campus of the National & Kapodistrian University of Athens (NKUA) in Psachna, Evia, Greece, and respective meteorological and tidal current data from the region. The results show that tidal energy may be used in a RES microgrid, where applicable, to satisfy the base load requirements, leading to a reduction in installed capacities of intermittent RES and storage, accompanied with cost reduction, especially in cases where a high load factor is observed or may be achieved, through demand response mechanisms. Such a hybrid microgrid configuration may be appropriate for regions where low velocity tidal and marine currents exist along with substantial solar and/or wind energy potential, such as the Mediterranean coast line and islands

A low cost - high efficiency electrodeposition device for the laboratory

A homemade electrodeposition device is presented, capable of depositing thin films of variable stoichiometry on cylindrical substrates offering control of electrolysis current, temperature and stirring velocity. The device design eliminates gravitational settling and uses a novel technique for fluid agitation in order to optimize deposition uniformity. The device surpasses traditional burato-style design in terms of gravitational settling of the solution and stirring homogeneity, as well as in terms of coating quality, i.e. cracking and blackened areas

A low cost - high efficiency electrodeposition device for the laboratory

A homemade electrodeposition device is presented, capable of depositing thin films of variable stoichiometry on cylindrical substrates offering control of electrolysis current, temperature and stirring velocity. The device design eliminates gravitational settling and uses a novel technique for fluid agitation in order to optimize deposition uniformity. The device surpasses traditional burato-style design in terms of gravitational settling of the solution and stirring homogeneity, as well as in terms of coating quality, i.e. cracking and blackened areas

A low cost - high efficiency electrodeposition device for the laboratory

A homemade electrodeposition device is presented, capable of depositing thin films of variable stoichiometry on cylindrical substrates offering control of electrolysis current, temperature and stirring velocity. The device design eliminates gravitational settling and uses a novel technique for fluid agitation in order to optimize deposition uniformity. The device surpasses traditional burato-style design in terms of gravitational settling of the solution and stirring homogeneity, as well as in terms of coating quality, i.e. cracking and blackened areas