Digital Repository of Hellenic Managing Authority of the Operational Programme "Education and Lifelong Learning" (EDULLL)
Not a member yet
3537 research outputs found
Sort by
Risks associated with next generation access networks investment scenarios
Get PDFThe deployment of next generation access networks (NGAs) is investigated from technical, regulatory and investment perspectives. A brief review of the possible network architectures and deployment scenarios of NGAs is provided. Risk calculations of these NGA scenarios are performed based on a fully detailed techno-economic model. Furthermore, the effectiveness of the European Commission's Recommendation on regulated access to NGAs, aiming to tackle the regulatory trade-off between encouraging investments and promoting competition, is discussed
Μελέτη της ικανότητας σχηµατισµού βιουµενίου διαφόρων στελεχών του παθογόνου βακτηρίου Salmonella enterica σε διαφορετικές συνθήκες, θερµοκρασίας, pH και σύστασης θρεπτικού µέσου ανάπτυξης.
Get PDFΣκοπός της παρούσας εργασίας ήταν η µελέτη της ικανότητας προσκόλλησης καισχηµατισµού βιουµενίου δεκατεσσάρων στελεχών του παθογόνου βακτηρίου Salmonella enterica κάτω από διαφορετικές συνθήκες, θερµοκρασίας (15 και 30°C), pH (5,5, 6,5 και 7,4) και σύστασης του θρεπτικού µέσου ανάπτυξης (πλήρης και ελλιπής σε θρεπτικά συστατικά).
The ability of fourteen strains of the pathogenic bacterium Salmonella enterica to attach and form bioflims was studied under in vitro experimental conditions simulating food production and processing environments. Different environmental conditions, temperature (15 και 30°C), pH (5,5, 6,5 και 7,4) and growth medium composition, were tested
Synthesis and Study of 2‑(Pyrrolesulfonylmethyl)‑N‑arylimines: A New Class of Inhibitors for Human Glutathione Transferase A1‑1
Get PDFOverexpression of human GSTA1-1 in tumor cells is part of MDR mechanisms. We report on the synthesis of 11 pyrrole derivatives as hGSTA1-1 inhibitors starting from 1-methyl-2-[(2-nitrobenzylsulfanyl]-1H-pyrrole. Molecular modeling revealed two locations in the enzyme H binding site: the catalytic primary one accommodating shorter and longer derivatives and the secondary one, where shorter derivatives can occupy. Derivative 9, displaying the highest inhibition and bearing a p-nitroarylimino moiety, and derivative 4, lacking this moiety, were studied kinetically. Derivative 9 binds (Ki(9) = 71 ± 4 μM) at the primary site competitively vs CDNB. Derivative 4 binds (Ki(4) = 135 ± 27 μM) at the primary and secondary sites, allowing the binding of a second molecule (4 or CDNB) leading to formation of unreactive and reactive complexes, respectively. The arylmethylsulfonylpyrrole core structure is a new pharmacophore for hGSTA1-1, whereas its derivative 9 may serve as a lead structure
Biocatalysis, Enzyme Engineering and Biotechnology
Get PDFEnzymes are biocatalysts evolved in nature to achieve the speed and coordination of nearly all the chemical reactions that define cellular metabolism necessary to develop and maintain life. The application of biocatalysis is growing rapidly, since enzymes offer potential for many exciting applications in industry. The advent of whole genome sequencing projects enabled new approaches for biocatalyst development, based on specialised methods for enzyme heterologous expression and engineering. The engineering of enzymes with altered activity, specificity and stability, using sitedirected mutagenesis and directed evolution techniques are now well established. Over the last decade, enzyme immobilisation has become important in industry. New methods and techniques for enzyme immobilisation allow for the reuse of the catalysts and the development of efficient biotechnological processes. This chapter reviews advances in enzyme technology as well as in the techniques and strategies used for enzyme production, engineering and immobilisation and discuss their advantages and disadvantages
Structure design in emulsions and foams: from model systems and quantitative methods to functional properties in real products and according knowledge transfer
Get PDFPolemon, grosse Schatten of the Old Academy
Get PDF"Two larger questions seem to me to arise as background to any inquiry into the nature of Polemon’s place in the Platonic tradition. The first is what it means to be a Platonist at all; and the second is the extent to which the
2
Stoicism of Zeno of Kition and his successors can reasonably be viewed – in the way that it was viewed by Antiochus of Ascalon, for example -- as a sort of ‘correction’, or ‘tidying-up’, of the teachings of Polemon" from the speec
«Η μουσική είναι Seva»: παράδοση, αυτοσχεδιασμός, συλλογική μνήμη και ο ρόλος του ερευνητή στο πεδίο
Get PDFThe following discussion presents an anthropological approach on issues of culture and music concerning the Sikh community in Tavros. In particular, the concept of “Seva” is revealed through fieldwork as a crucial idea which affects the community’s musical performance. Moreover, I examine the importance of “interview” as a methodological approach on the concept of “Seva”. In this matter, I argue that “interview”, as “seva”, provides a unique space, upon which “orality”, both in verbal and sonic terms, operates as a medium through which the past is regenerated into the present. Meanwhile, this dialogue between text and context reveals the importance of individual narratives and their contribution to the formation of a sense of community
Nonlinear slow light propagation in photonic crystal slab waveguides: theory and practical issues
Get PDFIn this paper, we consider the propagation of slow light optical pulses inside photonic crystal slab waveguides (PCSW) both from a theoretical and an application point-of-view. The numerical model used relies on a nonlinear envelope propagation equation that includes the effects of second and third order dispersion, optical losses and self phase modulation. Pulse propagation is examined both in the linear and nonlinear regime. It is numerically shown that for rates of 10Gb/s, the order of nanosecond delays can be achieved through the PCSW defect modes without excessive pulse broadening in the nonlinear regime. In the nonlinear case, it is shown that soliton pulses exhibit less broadening than pulses in the linear case. In comparing the linear and the non-linear case we consider launching pulses with the same initial full width at half maximum or the same RMS width. The influence of optical losses on the soliton pulse broadening factor is also incorporated and discussed providing a more practical perspective. The results demonstrate the potential of implementing a variety of linear and nonlinear signal processing applications in PCSWs, such as optical buffering