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The energy performance of buildings directive (EPBD) (91/2002/EU) opened the way for member states of European Union to create and apply a holistic approach on buildings’ energy performance. Taking into consideration the reduced ratio of new buildings, energy refurbishment of existing building stock appears as a nodal point. In particular, buildings in Greece accounts approximately 4 million, while 70% has been constructed before the implementation of the first Thermal Insulation Regulation (TIR), thus they do not have any insulation. So, there is an extremely high potential for energy conservation in Greek building stock. Therefore, an extensive field study was carried out in northern area of Greece in Thessaloniki, through a detailed questionnaire. The purpose of the research is to create an integrated thermal insulation scheme in order to succeed the highest mitigation of energy losses through building envelope. Retrofitting insulation solutions were evaluated and applied through various simulation sce...

Abstract Nowadays, residential heating and cooling are responsible for a significant part of the total global energy consumption. In order to create environmentally friendly buildings, the application of renewable energy technologies is recommended. Such a technology is GSHP 1 systems. This study examined the level of consumers׳ awareness on this technology, their perception on considering installing such a system, as well as the factors influencing the above issues. According to a logistic regression analysis, knowledge concerning the use of a GSHP system for residential use is positively related to the existence in the residence of a person with an occupation or interests associated to environment, technology or engineering, as well as the awareness about RES 2 issues and higher educational level. Also, considering installing a GSHP system is positively related to the existence in the residence of a person with an occupation or interests associated to environment, technology or engineering, awareness on RES and alternative technologies, as well as younger age groups, higher income groups, university and technical vocational education graduates.

Electric vehicles (EVs) are pivotal in addressing the escalating environmental crisis. While EV drivetrains excel compared to those of vehicles with internal combustion engines (ICE), their energy storage systems are hampered by limited range, lifespan, and lengthy charging times. Hybrid energy storage systems (HESS) present a viable current solution to these issues. This review thoroughly explores state-of-the-art in the emerging field of multisource EVs that utilize HESS, incorporating any combination of batteries (BTs), supercapacitors (SCs), flywheels (FWs), fuel cells (FCs), and/or transmotors. In addition, the paper systematically categorizes and evaluates different hybrid configurations, detailing potential topologies and their respective advantages and limitations. Moreover, the paper examines diverse control algorithms used to manage these complex systems, focusing on their effectiveness and operational efficiency. By identifying current research gaps and technological challenges, this study aims to delineate future research directions that could enhance the deployment and optimization of multisource EVs, thereby addressing critical challenges such as energy density, system reliability, and cost-effectiveness.

A new simulated annealing (SA) algorithm combined with a dynamic economic dispatch method has been developed for solving the short-term unit commitment (UC) problem. SA is used for the scheduling of the generating units, while a dynamic economic dispatch method is applied incorporating the ramp rate constraints in the solution of the UC problem. New rules concerning the tuning of the control parameters of the SA algorithm are proposed. Three alternative mechanisms for generating feasible trial solutions in the neighborhood of the current one, contributing to the reduction of the required CPU time, are also presented. The ramp rates are taken into account by performing either a backward or a forward sequence of conventional economic dispatches with modified limits on the generating units. The proposed algorithm is considerably fast and provides feasible near-optimal solutions. Numerical simulations have proved the effectiveness of the proposed algorithm in solving large UC problems within a reasonable execution time.

105 σ. ; Αντικείμενο της έρευνας στο πλαίσιο της διπλωματικής εργασίας, είναι η μελέτη των θερμικών ανωμαλιών που παρουσιάζονται στο νησί της Χίου. Με την αύξηση της ενεργειακής ζήτησης που παρουσιάζεται παγκόσμια και τη στροφή που επιχειρείται προς ηπιότερες μορφές ενέργειας, η γεωθερμία αναμένεται να παίξει πρωταγωνιστικό ρόλο με τις πολλαπλές εφαρμογές της. Αρχικά γίνεται εισαγωγή στα πετρώματα και την τεκτονική του νησιού προκειμένου να είναι σαφές το υπόβαθρο το οποίο μελετάται. Στη συνέχεια γίνεται αναφορά στον τρόπο με τον οποίο δημιουργείται η θερμική ενέργεια στο εσωτερικό της γής, η δομή ενός γεωθερμικού συστήματος και οι τρόποι λειτουργίας του. Σημαντική ενότητα αποτελεί η αναφορά στο αντικείμενο της οπτικοποίησης, η οποία εστιάζει στην απεικόνιση μοντέλων τριών διαστάσεων. Ακολουθεί η υλοποίηση, με την απόδοση ψηφιακού μοντέλου του υπεδάφους σε διαφορετικά βάθη, από γωλογικά δεδομένα τα οποία προέρχονται από το Ι.Γ.Μ.Ε. Η δημιουργία των ψηφιακών μοντέλων γίνεται με την χρήση του λογισμικού πακέτου Surfer, μέσω των μεθόδων Kriging και Moving Average, βάσει των οποίων προέκυψαν χάρτες και εποπτικά σχέδια τα οποία σχολιάζονται και αναλύνονται στο τέλος της εργασίας. ; This thesis focuses on the study of thermal anomalies observed in Chios island. Geothermics is expected to play a key role in the near future due to its multiple applications, as the increasing demand for energy is turning towards renewable sources. The thesis introduction concertrates on the island's rocks ana\d tectonics with the aim to provide an explicit picture of the underground examined. The generation of thermal energy in earth's interior, the structure of a geothermal system and thw ways of this system's establishment are further elements of consideration in this paper. Another important point is the visualization, which focuses in the three dimensional imaging of models. The implementation with the digital imaging of the underground model in several depths follows, based on geological data from the Institute of Geology and ...

We investigate the influence of structural modifications on the phosphorus doping of thin (0.4 /spl mu/m) LP-CVD polysilicon layers deposited at 620/spl deg/C on SiO/sub 2/ films intentionally grown with a thickness of 4 nm on a (111) oriented, silicon substrate. The measurements by XTEM and SIMS permitted to correlate the structure modifications with the doping properties after the various drive-in diffusion conditions in the temperature range of (900/spl deg/C-1000/spl deg/C) of the polysilicon layers.

The energy sector of the European Union (EU) is based mainly on fossil fuels and almost two-thirds of the energy demand is imported. In the future, fossil fuels are expected to strengthen their participation in the European energy balance and imports will amount to 70% of overall energy needs. On the other hand, the development of Renewable Energy Sources (RES) is a central aim of the European Commission's energy policy. RES hold a significant share in the 10 new countries recently joined the EU and the adoption of RES-related policies is of imperative importance for the joint cooperation of the new member states with the EU. This paper includes a review of RES status, related policies and prospects in each of the 10-new member states of EU.

Graphical user interfaces (GUI) provide interactive and intuitive visual communication to power system analysis application programs, enhancing the capabilities of engineers to conduct studies with ease and flexibility. As a result, since the late 1970s, a number of interactive graphical packages for power system analysis have been developed and are in widespread use. Object-oriented programming is gaining popularity, while the Windows environment is assuming a growing role in PC hardware platforms, due to its increased capabilities as a GUI environment. There are many different graphical packages for simulating, analyzing, and teaching power systems operations (built using such programming tools as C++, Object Pascal for Windows, or Visual Basic) that are the results of implementing object-oriented methodology in creating graphical user interfaces. This article focuses on possibilities offered by rapid application development (RAD) tools in building graphical user interfaces for Windows 3.X, Windows 95, and Windows NT platforms. RAD is a new way of programming that allows an application to be built interactively.

Small band gap molecular semiconductors are of interest for the development of transparent electronics. Here we report two near-infrared (NIR), n-type small molecule semiconductors, based upon an acceptor-donor-acceptor (A-D-A) approach. We show that the inclusion of molecular spacers between the strong-electron-accepting end group, 2,1,3-benzothiadiazole-4,5,6-tricarbonitrile, and the donor core affords semiconductors with very low band gaps down to 1 eV. Both materials were synthesized by a one-pot, 6-fold nucleophilic displacement of a fluorinated precursor by cyanide. Significant differences in solid-state ordering and charge carrier mobility are observed depending on the nature of the spacer, with a thiophene spacer resulting in solution processed organic field-effect transistors (OFETs) exhibiting excellent electron mobility up to 1.1 cm2 V-1 s-1. The use of silver nanowires as the gate electrode enables the fabrication of a semitransparent OFET device with an average visible transmission of 71% in the optical spectrum. ; The authors thank the Engineering and Physical Sciences Research Council (EPSRC) (EP/L016702/1 and EP/T028513/1), Global Research Laboratory Program of the National Research Foundation (NRF-2017K1A1A2013153), the Royal Society, and the Wolfson Foundation (Royal Society Wolfson Fellowship) for funding. M.I.N., M.H., and T.D.A. acknowledge funding from the King Abdullah University of Science and Technology (KAUST) Office of Sponsored Research (OSR) under Award Nos. OSR-2018-CARF/CCF-3079 and OSR-2020-CRG8-4095. F.E. thanks EPSRC for support via a Doctoral Prize Fellowship.