The exploitation of biomass for building space heating in Greece: Energy, environmental and economic considerations

The exploitation of forest and agricultural biomass residues for energy production may offer significant advantages to the energy policy of the relevant country, but it strongly depends on a number of financial, technological and political factors. The work in hand focuses on the investigation of the energy, environmental and financial benefits, resulting from the exploitation of forest and agricultural biomass residues, fully substituting the conventional fuel (diesel oil) for building space heating in Greece. For this investigation, the energy needs of a representative building are determined using the EnergyPlus software, assuming that the building is located across the various climate zones of Greece. Based on the resulting thermal energy needs, the primary energy consumption and the corresponding emissions are determined, while an elementary fiscal analysis is also performed. The results show that significant financial benefits for the end-user are associated with the substitution examined, even though increased emissions and primary energy consumption have been derived

Fast calculation of capacitances in silicon sensors with 3D and 2D numerical solutions of the Laplace's equation and comparison with experimental data and TCAD simulations

We have developed a software for fast calculation of capacitances in planar silicon pixel and strip sensors, based on 3D and 2D numerical solutions of the Laplace's equation. The validity of the 2D calculations was checked with capacitances measurements on Multi-Geometry Silicon Strip Detectors (MSSD). The 3D calculations were tested by comparison with pixel sensors capacitance measurements from literature. In both cases the Laplace equation results were compared with simulations obtained from the TCAD Sentaurus suite. The developed software is a useful tool for fast estimation of interstrip, interpixel and backplane capacitances, saving computation time, as a first approximation before using a more sophisticated platform for more accurate results if needed

Influenza in birds, pigs and humans: how strong is the species barrier?

Οι πρόσφατες επιζωοτίες της γρίπης των πτηνών από τον υψηλής λοιμογόνου ικανότητας Η5Ν1 και τα τυχαία κρούσματα ανθρώπων και άλλων θηλαστικών, συμπεριλαμβανομένωντων χοίρων και των αιλουροειδών, έχουν θέσει σε συναγερμό τη διεθνή επιστημονική κοινότητα. Νέα ερωτήματα έχουν προκύψει σχετικά με τη μετάδοση των ιών της γρίπης μεταξύ των ειδών και ο ρόλος του χοίρου ως "αναμιγνείον δοχείο" των ιών των πτηνών και του ανθρώπου έχει υποστεί κριτική. Ο κύριος σκοπός αυτής της ανασκόπησης είναι να εκτιμήσει την πιθανότητα της γρίπης των πτηνών και του χοίρου στο να προκαλέσουν αντίστοιχο λοιμώδες αναπνευστικό νόσημα στον άνθρωπο. Η μετάδοση των ιών της γρίπης μεταξύ των ειδών είναι σπάνια εξέλιξη γεγονότων και πολύ λίγοι ιοί έχουν πετύχει να εγκατασταθούν σε νέο είδος ξενιστή. Μέχρι την εμφάνιση του ίου Η5Ν1 το 1996 μόνο 3 περιπτώσεις ασθενών ανθρώπων από ιούς πτηνών είχαν αναφερθεί. Η μη μετάδοση από άνθρωπο σε άνθρωπο του Η5Ν1 αποδεικνύει ότι απαιτούνται εκτεταμένες αλλαγές του γενώματος του ίου για να υπερπηδηθεί ο φραγμός των ειδών. Αν και οι ιοί γρίπης των πτηνών έχουν απομονωθεί από χοίρους, μόνο σε μία περίπτωση ο ιός γρίπης των πτηνών Η I N I που μεταδόθηκε από άγριες πάπιες σε χοίρους ήταν ικανός για περαιτέρω εξάπλωση σε χοίρειο πληθυσμό.Η ευαισθησία των χοίρων στους ιούς υψηλής και χαμηλής λοιμογόνου ικανότητας των πτηνών έχει επιβεβαιωθεί σε πειραματικές μελέτες, αλλά η μετάδοση από χοίρο σε χοίρο δεν έχει αποδειχθεί. Επίσης, περιγράφεται η πειραματική και η φυσική μετάδοση, των υψηλής λοιμογόνου ικανότητας ιών, στα αιλουροειδή, μυς, νυφίτσες και πιθήκους του γένους μακάκους. Ακόμη παρουσιάζονται οι κυρίες διαφορές της λοιμογόνου ικανότητας του ίου ανάμεσα στα διάφορα είδη των θηλαστικών. Έτσι, η μελέτη της λοιμογόνου ικανότητας μπορεί να προσφέρει ιδέες και γνώσεις σχετικά με τα αίτια της περιορισμένης εξάπλωσης του ίου σε ένα νέο ξενιστή. Μπορούμε να συμπεράνουμε ότι, αντίθετα προς την κοινή άποψη, ο φραγμός των ειδών παραμένει ένα σοβαρό εμπόδιο για την εξάπλωση των νέων ιών γρίπης σε νέα είδη-ξενιστές, συμπεριλαμβανομένου και του ανθρώπου. Η εμπειρία μας με τους ιούς Η5Ν1 and Η7Ν7 θέτει σε αμφιβολία τις παλιές θεωρίες και αποδεικνύει όχι είναι ανεπαρκείς. Χρειάζεται περαιτέρω μελέτη των παραγόντων που επηρεάζουν και περιορίζουν τη μετάδοση των ιών της γρίπης από το ένα είδος στο άλλο για να γίνει περισσότερο κατανοητό και να αξιολογηθεί ο κίνδυνος της εμφάνισης νέας πανδημίας από ιούς γρίπης.The recent epizootics of the highly pathogenic H5N1 avian influenza in poultry and the occasional infections of humans and other mammals, including pigs and felines, have alerted the international scientific community. New questions over the interspecies transmission of influenza viruses have been raised and the role of the pig as a "mixing vessel" of avian and human viruses has been criticized. The major aim of this review is to evaluate the zoonotic potential of avian and swine influenza. Interspecies transmissions of influenza viruses are rare virus-evolution events and very few viruses have succeeded to become established in new host species. Until the appearance of the H5N1 virus in 1996 only 3 cases of humans infected with avian viruses were recorded. The lack of human-to-human transmission of H5N1 demonstrates that extensive changes in the virus genome are required in order to overcome the species barrier. Although avian influenza viruses have been isolated from pigs, only in one occasion an avian H I N I virus transmitted from wild ducks to pigs was able to further spread in the swine population. The susceptibility of swine to highly and low pathogenic avian viruses has been confirmed in experimental studies, but pig-to-pig transmission has not been demonstrated. Experimental and natural transmission of highly pathogenic avian viruses to felines, mice, ferrets and maqacues are also discussed, showing the major differences in the virus pathogenesis among different mammalian species. The study of this pathogenesis may offer insights to the reasons of limited virus spread within a new host. We may conclude that, contrary to common believes, the species barrier remains a serious obstacle for the spread of novel influenza viruses in new host species, including humans. Our experience with H5N1 and H7N7 has tested old established theories, proving them insufficient. Further study of the factors which influence and limit the transmission of influenza viruses from one species to another is needed to better understand and evaluate the risk of the emergence of new pandemic influenza viruses

Separation of a single photon and products of the π0,η,Ks0\pi^0,\eta, K^0_s meson neutral decay channels in the CMS electromagnetic calorimeter using neural network

The artificial neural network approach is used for separation of signals from a single photon $\gamma$ and products of the $\pi^0,\eta, K^0_s$ meson neutral decay channels on the basis of the data from the CMS electromagnetic calorimeter alone. Rejection values for the three types of mesons as a function of single photon selection efficiencies are obtained for two Barrel and one Endcap pseudorapidity regions and initial \Et of 20, 40, 60 and 100 GeV.Comment: 16 pages, uses cernrep.cls style fil

Induced oestrus in lactating sows by administration of PMS and HCG

Ό πειραματισμός αυτός έγινε σέ βιομηχανικού τύπου χοιροτροφική μονάδα δυναμικότητας 500 χοιρομητέρων. Σ' αυτόν πήραν μέρος 20 χοιρομητέρες πού χρησίμευσαν σαν μάρτυρες (ΤΙ) και άλλες 20 αντίστοιχα (Τ2), του ίδιου γενετικού δυναμικού πού διαβιούσαν κάτω άπό τις 'ίδιες συνθήκες εκτροφής, στις όποιες έγινε ή ακόλουθη αγωγή: (α) τήν 23η ήμερα μετά τό τοκετό 1.000 u.i PMS, (β) τήν 24η ήμερα 300 u.i. HGC, (γ) άπό 26-31η ήμερα 12ωρη απομάκρυνση των χοιριδίων άπό τις χοιρομητέρες και (δ) έκθεση των χοιρομητέρων στα ερεθίσματα του κάπρου επί 30' κάθε πρωί άπό τήν 26-31η ήμερα. Και για τίς δύο ομάδες (ΤΙ καί Τ2) ό απογαλακτισμός τών χοιριδίων έγινε τή 35η ήμερα. Τό μέγεθος των τοκετοομάδων, ή βιοσιμότητα μέχρι τή 35η ήμερα, τά σωματικά βάρη τών χοιριδίων μέχρι τή 35η ήμερα καί οί αποδόσεις τοΰ επομένου τοκετού δέν είχαν καμιά στατιστικά σημαντική διαφορά. Οί χοιρομητέρες τής ομάδας ΤΙ ήλθαν σέ οργασμό — όχεία τήν 44,75 ±1,1 ημέρα (ποσοστό 85% τών χοιρομητέρων — εγκυμοσύνη 90%) καί τής Τ2 τήν 35,85±1,4 ήμερα (ποσοστό 80% τών χοιρομητέρων — εγκυμοσύνη 75%) (Ρ<0,001). Ή όλη όμως πειραματική εργασία στην ομάδα τ2 προκάλεσε μεγάλα λειτουργικά προβλήματα στό χοιροστάσιο.The experiment was conducted in a livestock unit of 500 brood sows and comprised a total of 40 animals of the same genetic potential and living under the same management conditions. Of the above animals. 20 were used as controls (group Tl), while the remaining 20 (group T2) were treated as follows: a) on day 23 after farrowing, they were injected with. 1000 i.u. PMS, b) on day 24 they were injected with 300 i.u. of HCG, c) on days 21-24 the litters were removed from their dams for 12 hours daily, d) on days 26-31 the sows were exposed to the presence of the boar, for 30' every morning. All litters of both groups were weaned on day 35 after farrowing. There were no significant differences in litter size, survival and body weight of piglets to the 35th day, as well as in the yields of the animals at the subsequent parturition. The sows of group Tl came into oestrus on day 44.75 ± 1.1 d. (85% of the sows in oestrus - conception rate 90%), while those of group T2 came into oestrus on day 35.85 ± 1.4 d. (80% of the sows in oestrus - conception rate 75%) (P/0.001). The entire experimental work among the animals of group T2, however, caused considerable operational problems in the unit

Geothermal district heating networks: modelling novel operational strategies incorporating heat storage

The value of integrating a heat storage into a geothermal district heating system has been investigated. The behaviour of the system under a novel operational strategy has been simulated focusing on the energetic, economic and environmental effects of the new strategy of incorporation of the heat storage within the system. A typical geothermal district heating system consists of several production wells, a system of pipelines for the transportation of the hot water to end-users, one or more re-injection wells and peak-up devices (usually fossil-fuel boilers). Traditionally in these systems, the production wells change their production rate throughout the day according to heat demand, and if their maximum capacity is exceeded the peak-up devices are used to meet the balance of the heat demand. In this study, it is proposed to maintain a constant geothermal production and add heat storage into the network. Subsequently, hot water will be stored when heat demand is lower than the production and the stored hot water will be released into the system to cover the peak demands (or part of these). It is not intended to totally phase-out the peak-up devices, but to decrease their use, as these will often be installed anyway for back-up purposes. Both the integration of a heat storage in such a system as well as the novel operational strategy are the main novelties of this thesis. A robust algorithm for the sizing of these systems has been developed. The main inputs are the geothermal production data, the heat demand data throughout one year or more and the topology of the installation. The outputs are the sizing of the whole system, including the necessary number of production wells, the size of the heat storage and the dimensions of the pipelines amongst others. The results provide several useful insights into the initial design considerations for these systems, emphasizing particularly the importance of heat losses. Simulations are carried out for three different cases of sizing of the installation (small, medium and large) to examine the influence of system scale. In the second phase of work, two algorithms are developed which study in detail the operation of the installation throughout a random day and a whole year, respectively. The first algorithm can be a potentially powerful tool for the operators of the installation, who can know a priori how to operate the installation on a random day given the heat demand. The second algorithm is used to obtain the amount of electricity used by the pumps as well as the amount of fuel used by the peak-up boilers over a whole year. These comprise the main operational costs of the installation and are among the main inputs of the third part of the study. In the third part of the study, an integrated energetic, economic and environmental analysis of the studied installation is carried out together with a comparison with the traditional case. The results show that by implementing heat storage under the novel operational strategy, heat is generated more cheaply as all the financial indices improve, more geothermal energy is utilised and less fuel is used in the peak-up boilers, with subsequent environmental benefits, when compared to the traditional case. Furthermore, it is shown that the most attractive case of sizing is the large one, although the addition of the heat storage most greatly impacts the medium case of sizing. In other words, the geothermal component of the installation should be sized as large as possible. This analysis indicates that the proposed solution is beneficial from energetic, economic, and environmental perspectives. Therefore, it can be stated that the aim of this study is achieved in its full potential. Furthermore, the new models for the sizing, operation and economic/energetic/environmental analyses of these kind of systems can be used with few adaptations for real cases, making the practical applicability of this study evident. Having this study as a starting point, further work could include the integration of these systems with end-user demands, further analysis of component parts of the installation (such as the heat exchangers) and the integration of a heat pump to maximise utilisation of geothermal energy

Muscle and liver transcriptome characterization and genetic marker discovery in the farmed meagre, Argyrosomus regius

Meagre (Argyrosomus regius), a teleost fish of the family Sciaenidae, is part of a group of marine fish species considered new for Mediterranean aquaculture representing the larger fish cultured in the region. Meagre aquaculture started ~ 25 years ago in West Mediterranean, and the supply of juveniles has been dominated by few hatcheries. This fact has raised concerns on possible inbreeding, urging the need for genetic information on the species and for an assessment of the polymorphisms found in the genome. To that end we characterized the muscle and liver transcriptome of a pool of meagre individuals, from different families and phenotypic size, to obtain a backbone that can support future studies regarding physiology, immunology and genetics of the species. The assembled transcripts were assigned to a wide range of biological processes including growth, reproduction, metabolism, development, stress and behavior. Then, to infer its genetic diversity and provide a catalogue of markers for future use, we scanned the reconstructed transcripts for polymorphic genetic markers. Our search revealed a total of 42,933 high quality SNP and 20,581 STR markers. We found a relatively low rate of polymorphism in the transcriptome that may indicate that inbreeding has taken place. This study has led to a catalogue of genetic markers at the expressed part of the genome and has set the ground for understanding growth and other traits of interest in meagre.info:eu-repo/semantics/acceptedVersio