Open type ferry safety systems design for using LNG fuel

This feasibility study investigates the viability of employing Liquefied Natural Gas (LNG) fuel to an open type Ro-Ro passenger ferry and the potential challenges imposed with regard to the vessel safety systems. The study proposes appropriate methodology for converting the existing ship to run on LNG fuel and discusses all the necessary modifications to the ship’s safety systems; furthermore, the ship’s evacuation analysis is investigated accordingly. The basic requirements that the ship already complies with are initially reported for each safety system while the additional restrictions that need to be taken into consideration for employing LNG fuel are analysed; appropriate actions are proposed. Furthermore, a Hazard Identification Study (HAZID) is also carried out. Overall, the technical feasibility of the investigated scenario is clearly demonstrated; minimal modifications to the ship's safety systems in order to comply with the imposed safety rules are required for the specific type of ship

Long-term weight change and risk of breast cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC) study

Background: The role of obesity and weight change in breast-cancer development is complex and incompletely understood. We investigated long-term weight change and breast-cancer risk by body mass index (BMI) at age 20 years, menopausal status, hormone replacement therapy (HRT) and hormone-receptor status. Methods: Using data on weight collected at three different time points from women who participated in the European Prospective Investigation into Cancer and Nutrition (EPIC) study, we investigated the association between weight change from age 20 years until middle adulthood and risk of breast cancer. Results: In total, 150 257 women with a median age of 51 years at cohort entry were followed for an average of 14 years (standard deviation = 3.9) during which 6532 breast-cancer cases occurred. Compared with women with stable weight (+/- 2.5 kg), long-term weight gain >10 kg was positively associated with postmenopausal breast-cancer risk in women who were lean at age 20 [hazard ratio (HR) = 1.42; 95% confidence interval 1.22-1.65] in ever HRT users (HR = 1.23; 1.04-1.44), in never HRT users (HR = 1.40; 1.16-1.68) and in oestrogen-and-progesterone-receptor-positive (ERthornPRthorn) breast cancer (HR = 1.46; 1.15-1.85). Conclusion: Long-term weight gain was positively associated with postmenopausal breast cancer in women who were lean at age 20, both in HRT ever users and non-users, and hormone-receptor-positive breast cancer.Peer reviewe

A Body Shape Index (ABSI) achieves better mortality risk stratification than alternative indices of abdominal obesity: results from a large European cohort

Abstract: Abdominal and general adiposity are independently associated with mortality, but there is no consensus on how best to assess abdominal adiposity. We compared the ability of alternative waist indices to complement body mass index (BMI) when assessing all-cause mortality. We used data from 352,985 participants in the European Prospective Investigation into Cancer and Nutrition (EPIC) and Cox proportional hazards models adjusted for other risk factors. During a mean follow-up of 16.1 years, 38,178 participants died. Combining in one model BMI and a strongly correlated waist index altered the association patterns with mortality, to a predominantly negative association for BMI and a stronger positive association for the waist index, while combining BMI with the uncorrelated A Body Shape Index (ABSI) preserved the association patterns. Sex-specific cohort-wide quartiles of waist indices correlated with BMI could not separate high-risk from low-risk individuals within underweight (BMI < 18.5 kg/m2) or obese (BMI ≥ 30 kg/m2) categories, while the highest quartile of ABSI separated 18–39% of the individuals within each BMI category, which had 22–55% higher risk of death. In conclusion, only a waist index independent of BMI by design, such as ABSI, complements BMI and enables efficient risk stratification, which could facilitate personalisation of screening, treatment and monitoring

Thinking outside the plastic bag: How Greece can reduce the plastic bag consumption

In 2015 the EU introduced Directive 2015/720 on the reduction of the consumption of lightweight plastic carrier bags creating the first transnational agreement on plastic bag issue in the world. This Directive sets the scope within which Member States will design their own policies in order to reach a significant reduction in the plastic bag consumption over the following years. Greece is one of the countries that have to cover a long way towards the desired outcome, since every Greek consumes on average 363 plastic carrier bags per year, whereas the European average number is 175 plastic bags. The aim of this thesis is to examine whether or not there are both environmentally sound and efficient measures for the reduction in the consumption of plastic bags in Greece within the scope of the Directive, having in mind though that it is an extra advantage if these measures give incentives for improvements beyond the targets of the Directive. This thesis is based on an ex-ante policy evaluation framework that compares alternative policy options taking into account the requirements of the Directive, the priorities of Greece regarding the waste management in the next years and external factors such as market signals and technological development. The collection of data was done through a desktop literature review and interviews with affected stakeholders. The policy evaluation is a partly subjective process, since the final outcome depends on how the collected information is interpreted. For that reason, this thesis does not propose the best policy option among the examined measures but presents risks, costs, benefits and stakeholders’ positions per measure in an organized and easy-to-follow way in order for the policy makers to take advantage of this information and make the final political decision. It is worth mentioning though that according to the conducted evaluation there are policy measures that can be both environmentally sound and cost-effective on the condition that the possible risks are minimised. As a result, which of these options will bring the best results depends on how the affected stakeholders will respond to them (political acceptability and equity)

Argyle Cut, the Bond store, Sydney, 1919 [picture] /

Title from inscriptions and catalogue.; Part of the collection: Old Sydney etchings, 1908-1940.; Inscriptions: "Lionel Lindsay, 1919"--In pencil lower left; "Argyle Cut"--In pencil lower centre; "trial proof in black"--In pencil lower right.; Condition: Spotting, stained, yellowing and tears.; The art of Sir Lionel Lindsay / Joanna Mendelssohn, 183.; Also available online http://nla.gov.au/nla.pic-an10742752; S5587 proof

Αγορά ηλεκτρικής ενέργειας : από την απελευθέρωση στην ενεργειακή μετάβαση. Η εξέλιξη των μηχανισμών ανταγωνισμού και του ρυθμιστικού πλαισίου

Η εργασία παρακολουθεί την πορεία της αγοράς ηλεκτρικής ενέργειας από τον στόχο της απελευθέρωσης σε αυτόν της ενεργειακής μετάβασης. Για τον σκοπό αυτό, ακολουθείται η εξής δομή: Αρχικά, επιδιώκεται η ανάλυση της διαδικασίας της απελευθέρωσης σε ευρωπαϊκό και εθνικό επίπεδο. Ειδικότερα, παρουσιάζεται το κανονιστικό πλαίσιο της απελευθέρωσης, ήτοι οι τρεις γενιές νομοθετικών μέτρων της Ε.Ε., τα βασικά εργαλεία της τομεακής ρύθμισης που συνέβαλαν στην απελευθέρωση της αγοράς, δηλαδή ο διαχωρισμός και η πρόσβαση τρίτων στα δίκτυα, ενώ, στο τέλος σκιαγραφείται το ελληνικό μοντέλο της απελευθέρωσης, από την ενσωμάτωση της ευρωπαϊκής νομοθεσίας έως το Μοντέλο Στόχο, με την ανάδειξη της σημασίας των δημοπρασιών ΝΟΜΕ και του λιγνίτη για την απελευθέρωση της ελληνικής αγοράς. Ακολούθως, το ενδιαφέρον μετατοπίζεται στον παροντικό στόχο της ενεργειακής μετάβασης. Περιγράφεται η πορεία της Ε.Ε. από την απελευθέρωση στην απαλλαγή από τον άνθρακα, με την επισκόπηση των σημαντικότερων σημείων της Συνθήκης της Λισαβόνας, της Τέταρτης Δέσμης Μέτρων και της Πράσινης Συμφωνίας. Μέσα από αυτές τις ρυθμίσεις αναδεικνύεται η ανάγκη προώθησης των ΑΠΕ και συνεπώς δίνεται έμφαση στις σύγχρονες τεχνολογικές εξελίξεις, καθώς και στο ευρωπαϊκό και εθνικό πλαίσιο στήριξης τους. Τέλος, σχολιάζεται το επίκαιρο ζήτημα της αύξησης τιμών στην αγορά ενέργειας, σε συνδυασμό με τις δράσεις της Ευρώπης και των κρατών μελών για την αναχαίτισή της.The dissertation examines how the electricity market has moved from the goal of liberalization to that of energy transition. Initially, the regulatory framework for liberalization is presented, i.e. the three generations of EU legislative measures, as well as the main tools of sectoral regulation, unbundling and third party access. At the end, the Greek model of liberalization is outlined from the transposition of EU legislation to Target Model, highlighting the importance of auctions NOME and lignite. Then, interest shifts to the current goal of energy transition and in particular the reduction of carbon emissions with an overview of the key points of Lisbon Treaty, Fourth EU Package and Green Deal. Trough them, the need to promote RES is highlighted and therefore emphasis is placed on modern technological developments, as well as on the EU and national framework for their support. Finally, there is a comment for the high energy prices in conjunction with the actions of Europe and Member States to combat the issue

Study and design the update of the laboratory education in the field of high voltages

216 σ.Σκοπός της παρούσας διπλωματικής εργασίας είναι η μελέτη και η σχεδίαση της αναβάθμισης της εργαστηριακής εκπαίδευσης στο αντικείμενο των Υψηλών Τάσεων. Στo πλαίσιo αυτής της διπλωματικής προτείνονται πέντε εργαστηριακές ασκήσεις που διαθέτουν πλήρες και εκσυγχρονισμένο θεωρητικό υπόβαθρο και πειραματικό μέρος. Οι ασκήσεις αυτές επιλέχθηκαν με στόχο να καλύπτεται ένα ευρύ φάσμα των βασικών αντικειμένων μελέτης των Υψηλών Τάσεων. Η πρώτη, η δεύτερη και η τρίτη εργαστηριακή άσκηση μελετούν αντίστοιχα την παραγωγή και μέτρηση των υψηλών εναλλασσόμενων, συνεχών και κρουστικών τάσεων. Η τέταρτη και η πέμπτη μελετούν τα μονωτικά υλικά (στερεά, υγρά και αέρια). Κάθε μια από αυτές τις ασκήσεις αποτελείται από τρεις ενότητες : το θεωρητικό υπόβαθρο, το πειραματικό μέρος και ερωτήματα κατανόησης. Για να πιστοποιηθεί η ορθότητα των προτεινόμενων πειραματικών διατάξεων, τα εργαστηριακά πειράματα διεξήχθησαν στο Εργαστήριο Υψηλών Τάσεων του Ε.Μ.Π.. Στο τελικό στάδιο της εργασίας πραγματοποιήθηκε ανάλυση και επεξεργασία των μετρήσεων που καταγράφηκαν κατά τη διάρκεια των πειραμάτων και προέκυψαν τα ανάλογα συμπεράσματα.The purpose of this diploma thesis is to study and design the update of the laboratory education in the field of High Voltages. Within the scope of this thesis five laboratory exercises are proposed with complete and updated theoretical background and experimental parts. These laboratory exercises are chosen in order to cover a large area of the basic study fields of High Voltages. The first, the second and the third exercise study the generation and the measurement of high alternating, direct and impulse voltages respectively. The fourth and fifth laboratory exercises study the insulating materials (liquid, solid and gas). Each one of these exercises consists of three parts: theoretical background, experimental part and comprehension questions. The proposed experiments was carried out at the High Voltage Laboratory of N.T.U.A. in order to verify the correct design of the circuit diagrams. The measurements taken during the experiments were analyzed and the respective conclusions were reached.Σοφία Ν. Πέππ

Computational study of three-dimensional flow past an oscillating cylinder following a figure eight trajectory

The paper presents a computational study of three-dimensional flow past a cylinder forced to oscillate in a uniform stream, following a figure-eight trajectory. Flow simulations were performed for Re = 400, for different cases, defined in terms of the oscillation mode (‘counter-clockwise’ or ‘clockwise’), for values of the ratio, F, of the transverse oscillation frequency to the Strouhal frequency close to 1.0. The results demonstrate that, for F ≤ 1.0, counter-clockwise cylinder motion is associated with positive power transfer from the flow to the cylinder, corresponding to excitation; for the clockwise motion, power transfer is negative at intermediate to high amplitudes, corresponding to damping. For the clockwise mode, in the range F = 0.9–1.1, a transition to two-dimensional vortex street is identified for transverse oscillation amplitude exceeding a critical value. This results from the induced suction of vortices, which moves vortex formation and shedding closer to the cylinder surface, thus resulting in a narrower wake, characterized by an effective lower Reynolds number. Both oscillation modes are characterized by higher harmonics in the lift force spectrum, with the third harmonic being very pronounced, while even harmonics are present for the case of clockwise mode, resulting from a wake transition to a “S + P” mode.ISSN:2311-552

3D Reconstruction & Modeling of the Traditional Greek Trechadiri: “Aghia Varvara”

3D modeling techniques have grown increasingly prevalent in a variety of disciplines, including cultural heritage and ship design. The methodology used in the 3D reconstruction of a traditional Greek boat with the Trechadiri hull type named “Aghia Varvara” is presented in this study. The original boat was built in 1925 and is characterized as a modern cultural heritage monument by the Greek Ministry of Culture. The digital reconstruction of the boat is explained in detail, including 3D laser scanning and computer aided geometric design (CAGD), as well as the description of the 3D printing process. The boat’s 3D digital model has been used for the enrichment of the NAVS Project’s digital library, demonstrating the unique geometrical, typological, and cultural characteristics of Greek traditional shipbuilding, a living craft which listed on Greece’s National Inventory of Intangible Cultural Heritage