Sunrise to sunset optimization of thin film antireflective coatings for encapsulated, planar silicon solar cells

We present an approach for the optimization of thin film antireflective coatings for encapsulated planar silicon solar cells in which the variations in the incident spectra and angle of incidence (AOI) over a typical day are fully considered. Both the angular and wavelength dependences of the reflectance from the surface, absorptance within the coating, and transmittance into the device are calculated for both single- and doublelayer antireflection coatings with and without thin silicon oxide passivation layers. These data are then combined with spectral data as a function of time of day and internal quantum efficiency to estimate the average short-circuit current produced by a fixed solar cell during a day. This is then used as a figure of merit for the optimization of antireflective layer thicknesses for modules placed horizontally at the equator and on a roof in the UK. Our results indicate that only modest gains in average short-circuit current could be obtained by optimizing structures for sunrise to sunset irradiance rather than AM15 at normal incidence, and fabrication tolerances and uniformities are likely to be more significant. However, we believe that this overall approach to optimization will be of increasing significance for new, potentially asymmetric, antireflection schemes such as those based on subwavelength texturing or other photonic or plasmonic technologies currently under development especially when considered in combination with modules fixed at locations and directions that result in asymmetric spectral conditions

Emotional intelligence and work attitudes: predicting employees’ performance. A study on the administrative employees of Greek Universities

Σύμφωνα με τη διεθνή βιβλιογραφία οι βασικοί παράγοντες επιρροής της εργασιακής συμπεριφοράς των ατόμων που έχουν συνδεθεί με την εργασιακή αποδοτικότητα είναι η συναισθηματική νοημοσύνη, η εργασιακή αφοσίωση, η εργασιακή ικανοποίηση και η εργασιακή εξουθένωση. Στόχος της παρούσας διπλωματικής εργασίας είναι να καταγραφεί και να επισημανθεί αν και σε ποιο βαθμό η συναισθηματική νοημοσύνη και οι εργασιακές στάσεις (εργασιακή αφοσίωση – εργασιακή ικανοποίηση – εργασιακή εξουθένωση) καθορίζουν και βελτιώνουν την απόδοση των εργαζομένων διοικητικών υπαλλήλων στα δημόσια ελληνικά Πανεπιστήμια. Η πρωτοτυπία της συγκεκριμένης έρευνας έγκειται στο ότι δεν υφίσταται παρόμοια έρευνα σε διεθνή και εγχώρια βιβλιογραφία που να εξετάζει ταυτόχρονα την συναισθηματική νοημοσύνη και τις εργασιακές στάσεις σε σχέση με την απόδοση των εργαζομένων διοικητικών υπαλλήλων στα δημόσια ελληνικά Πανεπιστήμια. Στο θεωρητικό μέρος αναλύονται οι έννοιες της Συναισθηματικής Νοημοσύνης, των Εργασιακών Στάσεων και της Εργασιακής Απόδοσης καθώς και μοντέλα μέτρησής τους. Επιπλέον, πραγματοποιείται βιβλιογραφική ανασκόπηση για τους εξεταζόμενους παράγοντες (συναισθηματική νοημοσύνη, εργασιακή ικανοποίηση, εργασιακή αφοσίωση, εργασιακή εξουθένωση & εργασιακή απόδοση) ως προς την εργασία στην Τριτοβάθμια Εκπαίδευση. Μετά από έρευνα στο διοικητικό προσωπικό του Πανεπιστημίου Ιωαννίνων με ερωτηματολόγιο για τους εξεταζόμενους παράγοντες, διαπιστώθηκε ότι τα επίπεδα συναισθηματικής νοημοσύνης, εργασιακής αφοσίωσης και εργασιακής ικανοποίησης των συμμετεχόντων στην έρευνα κρίνονται ικανοποιητικά υψηλά, ενώ τα επίπεδα της εργασιακής εξουθένωσης – η οποία οδηγεί σε εκδήλωση αντιπαραγωγικών συμπεριφορών- κρίνονται κάτω του μετρίου. Ως εκ τούτου, η εργασιακή απόδοση του διοικητικού προσωπικού, αποτυπώνεται εξίσου υψηλή. Επιπροσθέτως, διαπιστώθηκε ότι oι παράγοντες που επηρεάζουν την απόδοση του διοικητικού προσωπικού είναι οι συναισθηματική νοημοσύνη και η εργασιακή αφοσίωση, ενώ δεν αποτυπώνεται συσχέτιση της εργασιακής ικανοποίησης και της εργασιακής εξουθένωσης με την εργασιακή απόδοση. Τέλος, διαπιστώθηκε ότι η Συναισθηματική Νοημοσύνη του διοικητικού προσωπικού επηρεάζει θετικά τις εργασιακές στάσεις (εργασιακή ικανοποίηση, εργασιακή αφοσίωση, εργασιακή εξουθένωση).According to the international literature, the main influencing factors of individuals' work behavior that have been linked to work efficiency are emotional intelligence, work engagement, job satisfaction and job burnout. The aim of this thesis is to record and point out whether and to what extent emotional intelligence and work attitudes (work engagement - job satisfaction - job burnout) determine and improve the performance of administrative employees in public Greek Universities. The originality of this research lies in the fact that there is no similar research in international and domestic literature that simultaneously examines emotional intelligence and work attitudes in relation to the performance of administrative employees in public Greek Universities. The theoretical part analyzes the concepts of Emotional Intelligence, Work Attitudes and Work Performance as well as their measurement models. In addition, a literature review is carried out on the examined factors (emotional intelligence, job satisfaction, work commitment, job burnout & work performance) in relation to work in Higher Education. The survey of the administrative staff of the University of Ioannina that contacted using a questionnaire on the examined factors, proved that the levels of emotional intelligence, work engagement and job satisfaction of the administrative employees are satisfactorily high, while the levels of job burnout -which leads to the manifestation of counterproductive behaviors- are below average. Therefore, the work performance of the administrative employees is recorded at the same high levels. Additionally, it was found that the factors that influence the performance of administrative employees, are emotional intelligence and work engagement, while no correlation between job satisfaction and job burnout with job performance is recorded. Finally, it was found that the emotional intelligence of administrative employees positively affects work attitudes (job satisfaction, work commitment, job burnout).16

Demand-Orientated Power Production from Biogas: Modeling and Simulations under Swedish Conditions

The total share of intermittent renewable electricity is increasing, intensifying the need for power balancing in future electricity systems. Demand-orientated combined heat and power (CHP) production from biogas has potential for this purpose. An agricultural biogas plant, using cattle manure and sugar beet for biogas and CHP production, was analyzed here. The model Dynamic Biogas plant Model (DyBiM) was developed and connected to the Anaerobic Digestion Model No. 1 (ADM1). Flexible scenarios were simulated and compared against a reference scenario with continuous production, to evaluate the technical requirements and economic implications of demand-orientated production. The study was set in Swedish conditions regarding electricity and heat price, and the flexibility approaches assessed were increased CHP and gas storage capacity and feeding management. The results showed that larger gas storage capacity was needed for demand-orientated CHP production but that feeding management reduced the storage requirement because of fast biogas production response to feeding. Income from electricity increased by 10%, applying simple electricity production strategies to a doubled CHP capacity. However, as a result of the currently low Swedish diurnal electricity price variation and lack of subsidies for demand-orientated electricity production, the increase in income was too low to cover the investment costs. Nevertheless, DyBiM proved to be a useful modeling tool for assessing the economic outcome of different flexibility scenarios for demand-orientated CHP production

All UK electricity supplied by wind and photovoltaics – The 30–30 rule

Based on weather and electricity demand data for the period 1984–2013, we develop a system model based on energy balance to determine the size of photovoltaic and wind generation combined with energy storage to provide a firm power supply for Great Britain. A simple graphical methodology is proposed where the required wind and PV generation capacities can be read off from a “system configuration diagram” as a function of the available storage size. We show, by way of illustration, that a reliable supply would be produced by a system based on PV and wind generators generating some 30% more electrical energy (approximately 100TWh p.a.) than the current electricity supply system if supplemented with 30 days of storage. In terms of generation capacities, the current 82GW of principally thermal generation would then be replaced by about 150GW of wind turbines and 35GW of PV arrays

Exploring the meaning and productivity of a polysemous prefix

This paper follows a corpus-based approach to the meaning and productivity of the Modern Greek prepositional prefix para-. A semantic categorization of the prefix is proposed and its productivity is measured across semantic categories, registers, text types and grammatical categories. Para- was found to be more productive in non-locational and evaluative meanings. Its most productive meaning is excess, while the locational meaning of proximity still remains strong. It is also more productive in written than spoken registers and the grammatical category of nouns. The findings of the study can have implications about the prefix’s ongoing grammaticalization and its affixal status

Early Growth and Development Impairments in Patients with Ganglioside GM3 Synthase Deficiency

Ganglioside GM3 synthase is a key enzyme involved in the biosynthesis of gangliosides. GM3 synthase deficiency (GSD) causes a complete absence of GM3 and all downstream biosynthetic derivatives. The individuals affected by this disorder manifest severe irritability, intractable seizures and profound intellectual disability. However, we have found that most newborns seem symptom-free for a period of time after birth. In order to further understand the onset of the disease, we investigated the early growth and development of patients with this condition through this study. We compared 37 affected individuals with their normal siblings and revealed that all children with GSD had relatively normal intrauterine growth and development, as their weight, length and head circumference were similar to their normal siblings at birth. However, the disease progresses quickly after birth and causes significant constitutional impairments of growth and development by 6 months of age. Neither breastfeeding nor gastrostomy tube placement made significant difference on growth and development as all groups of patients showed the similar pattern. We conclude that GSD causes significant postnatal growth and developmental impairments and the amount of gangliosides in breast milk and general nutritional intervention do not seem to alter these outcomes

Trends of European research and development in district heating technologies

There is a considerable diversity of district heating (DH) technologies, components and interaction in EU countries. The trends and developments of DH are investigated in this paper. Research of four areas related to DH systems and their interaction with: fossil fuels, renewable energy (RE) sources, energy efficiency of the systems and the impact on the environment and the human health are described in the following content. The key conclusion obtained from this review is that the DH development requires more flexible energy systems with building automations, more significant contribution of RE sources, more dynamic prosumers׳ participation, and integration with mix fuel energy systems, as part of smart energy sustainable systems in smart cities. These are the main issues that Europe has to address in order to establish sustainable DH systems across its countries.This research was conducted in collaboration between Wrocław University of Technology (Poland) and Brunel University London (UK). The support for the Polish team was by the Ministry of Science and HigherEducationunderGrantno.50532