Surface energy engineering of graphene

Contact angle goniometry is conducted for epitaxial graphene on SiC. Although only a single layer of epitaxial graphene exists on SiC, the contact angle drastically changes from 69{\deg} on SiC substrates to 92{\deg} with graphene. It is found that there is no thickness dependence of the contact angle from the measurements of single, bi, and multi layer graphene and highly ordered pyrolytic graphite (HOPG). After graphene is treated with oxygen plasma, the level of damage is investigated by Raman spectroscopy and correlation between the level of disorder and wettability is reported. By using low power oxygen plasma treatment, the wettability of graphene is improved without additional damage, which can solve the adhesion issues involved in the fabrication of graphene devices

CFD Applications in Energy Engineering Research and Simulation: An Introduction to Published Reviews

Computational Fluid Dynamics (CFD) has been firmly established as a fundamental discipline to advancing research on energy engineering. The major progresses achieved during the last two decades both on software modelling capabilities and hardware computing power have resulted in considerable and widespread CFD interest among scientist and engineers. Numerical modelling and simulation developments are increasingly contributing to the current state of the art in many energy engineering aspects, such as power generation, combustion, wind energy, concentrated solar power, hydro power, gas and steam turbines, fuel cells, and many others. This review intends to provide an overview of the CFD applications in energy and thermal engineering, as a presentation and background for the Special Issue “CFD Applications in Energy Engineering Research and Simulation” published by Processes in 2020. A brief introduction to the most significant reviews that have been published on the particular topics is provided. The objective is to provide an overview of the CFD applications in energy and thermal engineering, highlighting the review papers published on the different topics, so that readers can refer to the different review papers for a thorough revision of the state of the art and contributions into the particular field of interest

PURCHASE BEHAVIOUR RELATED TO HEATING SYSTEMS IN GERMANY WITH SPECIAL CONSIDERATION OF CONSUMERS' ECOLOGICAL ATTITUDES

Paper prepared for presentation at the Energy Engineering, Economics and Policy (EEEP) Conference Orlando (USA), 13th July 2009Consumer behaviour, Germany, Heating systems, Demand and Price Analysis, Q41, R20, M39,

Renewable energies course for Energy Engineering students at the Technical University of Catalonia (UPC)

Since September 2016, the Technical University of Catalonia (Universitat Politècnica de Catalunya, UPC) – BarcelonaTech has a new Campus in Barcelona City, the Diagonal-Besòs Campus. In this new Campus appears the Eastern Barcelona School of Engineering (Escola d’Enginyeria de Barcelona Est, EEBE), with new Bachelor’s and Master’s Degrees. In this framework, also since September 2016, the EEBE is offering the new 4-year Bachelor’s Degree in Energy Engineering with a total number of 240 ECTS credits. Current article deals with the inclusion of the course about sizing and design of renewable energy systems in the context of this degree. In particular, and although this topic was eventually abandoned in the initial degree curriculum, the paper presents the development of a 3rd-year course, Renewable Energies, that focuses on this topic.Postprint (published version

Faculty of Chemical and Energy Engineering

The toxicological effect of lauric acid based insecticide was investigated in terms of mode of action on aphids target system. Treated leaves were sprayed with different insecticides, which were lauric acid, cinnamaldehyde and malathion at 50µg/ml concentration to compare the effect of the pesticides on reproduction, growth development and feeding activity of aphids. The total number of new born nymphs produced and the relative development stage of nymphs were significantly reduced in all treatments compared to untreated leaves. Number of new born nymphs treated using lauric acid based pesticide was 6.0 ± 1.41 nymphs/day and the growth development rate at second day post treatment was rDS=1.07 ± 0.10. This data showed no significant difference with the data obtained when cinnamaldehyde and malathion were used as positive controls but the results were significantly different from the results obtained using untreated leaves (22.5 ± 3.54 nymphs/day, rDS=1.82 ± 0.02). Lauric acid was also shown to reduce the feeding activity of aphids. The study demonstrated that lauric acid was toxic to aphids. It has the ability to slow down the reproduction system, reduce growth development rate and decrease feeding activity of aphids (Aphis gosyypii Glover)

Solar Energy Engineering: Processes and Systems

Errata pdf inserted.Η βιβλιοθήκη διαθέτει αντίτυπο του βιβλίου σε έντυπη μορφή με ταξινομικό αριθμό: TJ810 .K35 2009With the threat of global warming, and the gradual depletion of petroleum supplies, solar electric power is rapidly becoming significant part of our energy mix. The range of solar cells spans different materials and different structures in the quest to extract maximum power from the device while keeping the cost to a minimum. Devices with efficiency exceeding 30% have been demonstrated in the laboratory. Solar Energy Engineering: Processes and Systems. Solar Energy Processes and Systems includes all areas of solar energy engineering. All subjects are presented from the fundamental level to the highest level of current research. The book includes subjects such as energy related environmental problems, solar collectors, solar water heating, solar space heating and cooling, industrial process heat, solar desalination, photovoltaics, solar thermal power systems and modelling of solar systems including the use of artificial intelligence systems in solar energy systems modelling and performance prediction

Congress, Compacts, and Interstate Authorities

This paper summarises the authors’ own teaching experiences from two large MSc-level courses taught as part of several international Master programmes related to Sustainable Energy Engineering, organized by the Department of Energy Technology at the Royal Institute of Technology (KTH) in Stockholm, Sweden.   Some important hinders and obstacles to effective learning are presented and discussed, addressing especially certain challenges for the students and their effect on student performance. Observations have been made throughout several years of increasing demand for energy- and sustainability-related knowledge by ever larger student groups. The growing number of international students and the fact that many students are aiming at expanding their abilities by specialising in energy engineering without having the necessary background, as well as the fact that many students following certain non-engineering programmes focusing on environmental or sustainability issues need nevertheless to study also purely engineering courses, brings many positive characteristics to the blended student team but also displays serious challenges to the practical optimisation of the learning activities, the intended learning outcomes, the speed of advancement in knowledge, and the general quality of education for such a diverse group of students. Possible improvements and augmentations of the learning activities with the goal of finding solutions to these challenges on both a programme level and course level are proposed and subjected to testing in recent student batches. The expected results in terms of improved student performance, and the plausible further extension of this work, are introduced and analysed.QC 20120308</p

Solar energy systems course for Energy Engineering students in the context of the European higher education area

The Bologna Process is a voluntary intergovernmental European cooperation initiative that led to the creation of the named European Higher Education Area (EHEA). EHEA was formed to promote mobility, increase academic recognition and attract students and staff from around the world to Europe. In this framework, since 2009, the Barcelona College of Industrial Engineering (Escuela Universitaria de Ingeniería Técnica Industrial de Barcelona – EUETIB) of the Technical University of Catalonia – BarcelonaTech (UPC) is offering the 4-year Bachelor Degree in Energy Engineering since 2009 with a total number of ECTS credits of 240. Current article deals with the inclusion of the sizing and design of solar energy systems in the context of this degree. In particular, and although this topic was eventually abandoned in the initial degree curriculum, the paper deals with the development of a 3rd-year course, Energy Integration, that focuses on this topic.Peer ReviewedPostprint (published version

??????????????? ??????????????? ?????? ????????? ?????? ?????? ?????? ??????

Department of Energy Engineering (Energy Engineering)Solid oxide fuel cells (SOFCs) are recognized as next generation environmentally friendly energy conversion devices due to their high energy conversion efficiency, fuel flexibility, efficient reclamation of waste heat, and low pollutant emissions. Nevertheless, the commercialization of SOFCs has been impeded by reason of some issues associated with the high operating temperatures (800-1000oC) such as undesired reactions between cell components, high cost, and material compatibility challenges. Thus, reducing the operating temperatures toward an intermediate temperature range (600-800oC) is essential to overcome the aforementioned problems. In intermediate temperature SOFCs (IT-SOFCs), however, electrocatalytic activity toward oxygen reduction reaction at the cathode is significantly decreased, which in turn causes insufficient fuel cell performance. Current researches, therefore, have been focused on enhancing the performance of cathode for effective IT-SOFC operation. In this regard, the infiltration method could be an excellent cathode fabrication method, considering its outstanding advantages toward intermediate temperature operation. First, each optimized sintering temperature of cathode and electrolyte can be applied, ensuring the favorable characteristics for IT-SOFC operation. Second, due to relatively low sintering temperature, nano structured cathodes can be formed, resulting in enlarged surface area and enhancement of electrochemical performance. Finally, long term stability is improved because the thermal expansion coefficient between cathode and electrolyte is minimized. This thesis mainly focuses on the fabrication of SOFC cathode by the infiltration method to achieve high fuel cell performance in the intermediate temperature range. Herein, my research paper studying infiltrated cathode materials for IT-SOFC is presented as follows. - A Nano-structured SOFC Composite Cathode Prepared via Infiltration of La0.5Ba0.25Sr0.25Co0.8Fe0.2O3-?? into La0.9Sr0.1Ga0.8Mg0.2O3-?? for Extended Triple Phase Boundary Areaclos