Εκτίμηση αιολικού δυναμικού στην περιοχή των Κυθήρων

Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Επιστήμη και Τεχνολογία Υλικών

Soft Sensors in digital healthcare monitoring

Stretchable sensors are a class of materials with applications across research fields from healthcare to structural engineering. Despite the extensive research aiming to improve the performance of individual materials or components, stretchable sensor devices are difficult to implement because conventional electronic components, mainly used for processing, which are rigid, have to make contact with soft components reliable enough to withstand real-world usage. This thesis introduces a method for creating electrical contacts that can be robustly attached onto soft, stretchable conductive polymer composites on one side and soldered to metal wires on the other side. Mechanically robust electrical contacts were developed to interface (soft) silicone-based strain sensors with conventional (hard) solid-state electronics using a nanoporous silicon-copper contact. Contacts are mounted on custom-made and commercial soft strain sensitive silicone sensors. The contacts are shown to be reliable under large deformations, then compared with a commonly used alternative under real-world strain conditions. The layered structure of the device creates a complex electronic component deriving from the silicon-copper Schottky junction. This thesis tests the versatility of the technology through a series of real-world applications. The silicon-copper contacts were used to produce a series of proof-of-concept devices, including a wearable respiration monitor, leg band for exercise monitoring, and squeezable ball to monitor rehabilitation of patients with hand injuries or neurological disorders. The sensor is shown to operate and detect multiple modes of motion regardless of placement on the body. Next, a proof-of-concept device was employed to measure hand grip strength. The optimized sensor can detect grip strength with high sensitivity. The hardness of the device was shown to increase sensitivity when healthy humans performed manual exercises and completed digital tasks. Providing patients with these devices can help monitor their rehabilitation following hand injuries or neurological disorders. This can be done through self-led at-home therapy which has been shown to improve treatment, engagement, long-term lifestyle adherence, while avoiding repeated visits to clinics which plays an important role in frequency of therapy, effectiveness, and accessibility.Open Acces

Students' mathematics performance and their attitude toward the learning of mathematics: an attempt to explore their relationship

The present study was an exploratory study aimed at investigating the relationship between Year 7 students' attitudes towards mathematics and their mathematics performance. Using random sampling 29 High Schools were selected from all over the country. The final sample comprised 714 Year 7 students. The research revealed that high performance in mathematics is associated with more positive students' attitudes toward mathematics learning. The most significant finding of the study is that Year 7 students in Greek High schools demonstrated a serious weakness in solving real life problems using the mathematics they have been taught

Promoting STEM content epistemology in Technology enhanced collaborative learning environments

In this paper the exploitationof a technologically supported learning environment is proposed so that teachers gain a deeper understanding of STEM (Science, Technology, Engineering and Mathematics) content epistemology, they become familiarized with the STEM methodology as well as they realize its added value in education settings. In this paper, a distance learning program (e-course) was developed to train teachers in the STEM teaching methodology. Sixteen teachers of Primary and Secondary sectorsof education participated in the program through implementing the Edmodo collaborative platform. The Cognitive Apprenticeship model, as a model of effective training in STEM methodology, combined with the Jigsaw Collaborative Strategy was applied. The experimental process was conducted in the context of problem-based learning while quantitative analysis was applied for the collection of data. The results of the teachers’ evaluation indicated that their involvement in STEM content implemented in an electronically appropriately designed environment, could enhance literacy in STEM content epistemology and the collaborative skills of learners

Η συμπλήρωση ή αποσαφήνιση πληροφοριών και δικαιολογητικών κατά την ανάθεση των δημοσίων συμβάσεων και των συμβάσεων παραχώρησης

Στο πρώτο μέρος της μελέτης επιχειρείται η κατά το δυνατόν πληρέστερη ανάλυση της θεμελιώδους αρχής της τυπικότητας κατά το προσυμβατικό στάδιο, μέσα από τις γενικές αρχές του ενωσιακού δικαίου, τη νομολογία αλλά και τις ίδιες τις διατάξεις του άρθρου 102 του Ν. 4412/2016. Στο δεύτερο μέρος της μελέτης ακολουθεί η παρουσίαση της προβληματικής που σχετίζεται με την κάμψη της αρχής της τυπικότητας προς όφελος του ανταγωνισμού, με σκοπό την αποτελεσματική δράση της διοίκησης· αναδεικνύεται δε στο εν λόγω μέρος η σημασία της αρχής της επιείκειας. Εν συνεχεία, στο τρίτο μέρος αναδεικνύεται η προβληματική των σχέσεων, οι οποίες αναπτύσσονται ανάμεσα στους παράγοντες ενός δημοσίου διαγωνισμού, ήτοι μεταξύ των αναθετουσών αρχών/ αναθετόντων φορέων και των οικονομικών φορέων, όπως αυτές έχουν διαχρονικά διαπλαστεί, επιχειρείται δε μια εκτίμηση της προοπτικής που δημιουργείται μετά την τροποποίηση προς το επιεικέστερο του νομικού καθεστώτος των διευκρινίσεων. Η μελέτη ολοκληρώνεται με την παρουσίαση των συμπερασμάτων και των θέσεων του γράφοντος, όπως διατυπώνονται μετά από την έρευνα των τιθέμενων ζητημάτων.The first part of the study attempts to analyse as fully as possible the fundamental principle of formality during the pre-contractual stage, through the general principles of EU law, case law and the provisions of article 102 of Law 4412/2016. In the second part of the study, the problematic issue related to the bending of the principle of formality in favour of competition, in order for the administration to act effectively, is presented; the importance of the principle of leniency is highlighted in this part, as well. The third part highlights the problematic issue of the relations between the parties involved in a public tender procedure, i.e. between the contracting authorities/entities and the economic operators, as they have developed over time, and attempts to assess the prospects that have emerged following the amendment of the legal regime for clarifications. The study concludes with the presentation of the author's conclusions and positions, as formulated after researching the issues raised

Compound and acutely ruptured false aneurysm of the brachial artery: a case report

<p>Abstract</p> <p>Introduction</p> <p>A patient with a neglected, compound acutely ruptured false aneurysm of the brachial artery which developed after a periprosthetic fracture of the right humerus, is reported.</p> <p>Case presentation</p> <p>An 84-year-old Greek woman underwent right shoulder hemiarthroplasty 2 years before a periprosthetic fracture which was treated conservatively in another hospital. After removing the U-slab herself, she noticed the development of an ulcer on the mid-humerus, with continuous oozing but no fever. This led to above-elbow amputation in an attempt to save the patient's life.</p> <p>Conclusion</p> <p>It is hoped that by awareness of such a possibility coupled with an early diagnosis based on the clinical picture and imaging modalities, such unfortunate results can be avoided in the future. In case of increasing displacement at the fracture site and excessive local swelling, the possibility of the presence of a false brachial aneurysm should be ruled out despite the presence of normal perfusion of the hand and palpable radial and ulnar pulses.</p