Introduction to Big Data in Education and Its Contribution to the Quality Improvement Processes

In this chapter, we introduce the readers to the field of big educational data and how big educational data can be analysed to provide insights into different stakeholders and thereby foster data driven actions concerning quality improvement in education. For the analysis and exploitation of big educational data, we present different techniques and popular applied scientific methods for data analysis and manipulation such as analytics and different analytical approaches such as learning, academic and visual analytics, providing examples of how these techniques and methods could be used. The concept of quality improvement in education is presented in relation to two factors: (a) to improvement science and its impact on different processes in education such as the learning, educational and academic processes and (b) as a result of the practical application and realization of the presented analytical concepts. The context of health professions education is used to exemplify the different concepts

Ultrasound-Assisted Preparation Methods of Nanoparticles for Energy-Related Applications

Ultrasound (US) technology is already into the research field providing a powerful tool of producing nanomaterials or being implicated in decoration procedures of catalyst supports for energy applications and material production. Toward this concept, low or/and high-frequency USs are used for the production of nanoparticles, the decoration of catalytic supported powders (carbon-based, titania, and alumina) with nanoparticles, and the production of metal-organic frameworks (MOFs). MOFs are porous, crystalline materials, which consist of metal centers and organic linkers. Those structures demonstrate high surface area, open metal sites, and large void space. All the above produced materials are used in heterogeneous catalysis, electrocatalysis, photocatalysis, and energy storage. Batteries and fuel cells are popular systems for electrochemical energy storage, and significant progress has been made in nanostructured energy materials in order to improve these storage devices. Nanomaterials have shown favorable properties, such as enhanced kinetics and better efficiency as catalysts for the oxygen reduction reaction (ORR)

Sonochemical synthesis of Metal Organic Frameworks (MOFs) for electrocatalytic applications

The aim of the current doctoral dissertation is the study of the use of ultrasounds as an alternative way of preparing MOFs, its direct comparison with conventional methods, and their characterization, in order to achieve lower reaction time, shorter particle size and improved final properties, whereas selected MOFs were tested as electrocatalysts. 9 MOFs structures were prepared, of which 5 sonochemical preparations are new in the literature. MOFs have been characterized by X-ray diffraction (XRD) and Rietveld analysis to identify their crystal structure, Scanning Electron Microscopy (SEM) to study morphology and size distribution, and Thermogravimetric Analysis (TGA) to study their thermal stability. Firstly, 2,5-dihydroxy terephthalic acid (H4dhtp) was studied as the organic linker and in particular with cobalt as the metal center to form the Co-MOF-74 structure. During the preparation of this MOF (through a series of 14 experiments) the ultrasound conditions, such as the amplitude and the reaction duration, were fully investigated for their optimization, showing a direct correlation towards the crystallinity and the particle size. It was observed that shorter reaction times (~30 min) and lower amplitude (<65 %) can lead to smaller particles but also smaller crystallites (as calculated via the Scherrer equation). In addition, Mg, Zn, Ni and Mn were also used as metal centers producing the same chemical structure (M2dhtp) and crystal system of MOF-74 (Trigonal, R 3 ̅ (No. 148)), as a way to study the different properties that each metal offers in the final MOF structure. On the other hand, alternative metals, such as calcium and strontium, which are chemically related to magnesium, since they belong to the group of alkaline earths, were examined as well. Following the experimental conditions of MOF-74, CPO-22 with Sr(H2dhtp)(H2O) formula, which belongs to the monoclinic crystal system (C2/c (No. 15)) was successfully prepared by both synthesis methods. In contrast, for calcium, CPO-20 with the chemical formula Ca(H2dhtp)(H2O)2, which belongs to the monoclinic crystal system (P21/n (No. 14)), was only obtained through the sonochemical synthesis, whereas the solvothermal method yielded Ca(H2dhtp)(DMF), which belongs to the triclinic crystal system (P 1 ̅ (No. 2)). In addition, other organic ligands such as adipic acid (adp), 2-methylimidazole (Hmim), trimesic acid (H3BTC) and 4,4΄-dipyridine (bpy) were also used to form Zn-adp, ZIF-8 (Zn-mim), HKUST-1 (Cu-BTC)/MOF-808 (Zr-BTC) and Ni-BTC-bpy structures respectively. The energy-related electrochemical applications investigated in this dissertation include the carbon dioxide reduction and zinc-air batteries. In particular, a lab-scale dual electrochemical cell (H-type) was designed and the necessary analysis protocol was set up in order to study some of the prepared MOFs on the CO2 reduction reaction (CO2RR). Their electrocatalytic activity was investigated via the faradaic efficiency (FE) as quantified by gas chromatography. A series of zinc-based MOFs (ZIF-8, Zn-adp, Zn-MOF-74) were chosen, prepared both conventionally and sonochemically, which have CO as their main product leading to satisfactory FE. However, the limitation of hydrogen evolution reaction (HER) remains a major problem in the literature as a CO2RR competitive reaction. Finally, a preliminary study was performed on the application of MOFs in Zn-air batteries, comparing and evaluating MnO2, which is popular in the literature for its electrochemical properties, a combination of MnO2-MWCNTs and the sonochemically prepared Ni-MOF-74 and HKUST-1(Cu) as cathodes. The MOFs gave satisfactory results, achieving quite good stability in short charge-discharge cycles (more than 360 consecutive cycles lasting 120 hours) without cell deterioration, but further research is needed to select suitable metal centers and ligands, while their catalytic activity could be enhanced by incorporating carbon structures and/or metal oxides.Αντικείμενο της παρούσας διδακτορικής διατριβής είναι η μελέτη της χρήσης των υπερήχων ως εναλλακτικός τρόπος σύνθεσης MOFs, η άμεση σύγκρισή τους με τις συμβατικές μεθόδους και ο χαρακτηρισμός τους, με σκοπό την επίτευξη χαμηλότερου χρόνου αντίδρασης, μικρότερου μεγέθους σωματιδίων και βελτιωμένων τελικών ιδιοτήτων, ενώ επιλεγμένα MOFs εξετάστηκαν ως ηλεκτροκαταλύτες. Παρασκευάστηκαν 9 δομές MOFs, εκ των οποίων 5 ηχοχημικές συνθέσεις είναι νέες στη βιβλιογραφία. Τα MOFs έχουν χαρακτηριστεί μέσω περίθλασης ακτίνων Χ (XRD) και ανάλυσης Rietveld για την ταυτοποίηση της κρυσταλλικής τους δομής, ηλεκτρονικού μικροσκοπίου σάρωσης (SEM) για τη μελέτη της μορφολογίας και της κατανομής του μεγέθους, και θερμοζυγού (TGA) για τη μελέτη της θερμικής τους σταθερότητας. Αρχικά, μελετήθηκε το 2,5-διυδρόξυ τερεφθαλικό οξύ (H4dhtp) ως οργανικός συνδέτης και ειδικότερα με κοβάλτιο ως μεταλλικό κέντρο για τη δημιουργία της δομής Co-MOF-74. Κατά την παρασκευή του συγκεκριμένου MOF (μέσω μιας σειράς 14 πειραμάτων) ερευνήθηκαν πλήρως οι συνθήκες ηχοβόλησης, όπως η εφαρμοζόμενη ισχύς και η διάρκεια της αντίδρασης, με στόχο τη βελτιστοποίησή τους, επιδεικνύοντας άμεση συσχέτιση με την κρυσταλλικότητα και το μέγεθος των σωματιδίων. Παρατηρήθηκε ότι μικρότεροι χρόνοι αντίδρασης (~30 min) και ποσοστά ισχύος (< 65 %) οδηγούν σε μικρότερα σωματίδια, αλλά και μικρότερους κρυσταλλίτες (όπως διαπιστώθηκε από την εξίσωση Scherrer). Επιπρόσθετα, χρησιμοποιήθηκαν και τα Mg, Zn, Ni και Mn ως μεταλλικά κέντρα τα οποία καταλήγουν στην ίδια χημική δομή (M2dhtp) και κρυσταλλικό σύστημα του MOF-74 (Τριγωνικό, R 3 ̅ (No. 148)), μελετώντας τις διαφορετικές ιδιότητες που προσφέρει το κάθε μέταλλο στο τελικό MOF. Από την άλλη πλευρά, ερευνώντας τη χρήση εναλλακτικών μετάλλων εξετάστηκε η χρήση του ασβεστίου και του στροντίου που παρουσιάζουν χημική συγγένεια με το μαγνήσιο, ανήκοντας στην ομάδα των αλκαλικών γαιών. Ακολουθώντας τις πειραματικές συνθήκες του MOF-74, το CPO-22 με χημικό τύπο Sr(H2dhtp)(H2O), το οποίο ανήκει σε μονοκλινές κρυσταλλικό σύστημα (C2/c (No. 15)) παρασκευάστηκε επιτυχώς και με τις δυο μεθόδους σύνθεσης. Αντίθετα, για το ασβέστιο, μέσω της ηχοχημικής σύνθεσης παραλήφθηκε το CPO-20 με χημικό τύπο Ca(H2dhtp)(H2O)2, το οποίο ανήκει σε μονοκλινές κρυσταλλικό σύστημα (P21/n (No. 14)), ενώ μέσω της διαλυτοθερμικής μεθόδου παραλήφθηκε το Ca(H2dhtp)(DMF), το οποίο ανήκει σε τρικλινές κρυσταλλικό σύστημα (P 1 ̅ (No. 2)). Επιπλέον, έγινε χρήση και άλλων οργανικών συνδετών, όπως αδιπικό οξύ (adp), 2-μεθυλιμιδαζόλιο (Hmim), τριμεσικό οξύ (H3BTC) και 4,4΄-διπυριδίνης (bpy) για το σχηματισμό των δομών Zn-adp, ZIF-8 (Zn-mim), HKUST-1(Cu-BTC)/MOF-808 (Zr-BTC) και Ni-BTC-bpy αντίστοιχα. Οι ηλεκτροχημικές εφαρμογές που διερευνήθηκαν στην παρούσα διατριβή αφορούν την ενέργεια και περιλαμβάνουν την αναγωγή του διοξειδίου του άνθρακα και τις μπαταρίες ψευδαργύρου-αέρα. Ειδικότερα, κατασκευάστηκε πειραματική διάταξη διπλού ηλεκτροχημικού κελιού (H-type cell) και στήθηκε το απαραίτητο πρωτόκολλο μετρήσεων για την εξέταση της ηλεκτροκαταλυτικής δράσης στην αντίδραση αναγωγής CO2 (CO2RR) ορισμένων εκ των παρασκευασμένων MOFs μελετώντας την απόδοση Faraday (FE) ως προς το επιθυμητό προϊόν με ποσοτικοποίηση μέσω αέριας χρωματογραφίας. Ερευνήθηκε μια σειρά MOFs με ψευδάργυρο ως το μεταλλικό κέντρο (ZIF-8, Zn-adp, Zn-MOF-74), παρασκευασμένα συμβατικά και ηχοχημικά, τα οποία έχουν ως κύριο προϊόν το CO οδηγώντας σε ικανοποιητικές FE. Ωστόσο, ο περιορισμός της αντίδρασης έκλυσης υδρογόνου (HER) παραμένει σημαντικό πρόβλημα στη βιβλιογραφία ως ανταγωνιστική αντίδραση της CO2RR. Τέλος, πραγματοποιήθηκε μια προκαταρκτική μελέτη για την εφαρμογή MOFs σε μπαταρίες Zn-air, συγκρίνοντας και αξιολογώντας ως καθόδους το MnO2, το οποίο είναι δημοφιλές στη βιβλιογραφία για τις ηλεκτροχημικές του ιδιότητες, έναν συνδυασμό MnO2-MWCNTs και τα ηχοχημικά παρασκευασμένα Ni-MOF-74 και HKUST-1(Cu). Τα MOFs που εξετάστηκαν έδωσαν ικανοποιητικά αποτελέσματα επιτυγχάνοντας αρκετά καλή σταθερότητα σε σύντομους κύκλους φόρτισης-εκφόρτισης (περισσότεροι από 360 διαδοχικοί κύκλοι σε διάρκεια 120 ωρών) χωρίς αλλοίωση του κελιού, αλλά χρειάζεται περαιτέρω έρευνα για την επιλογή κατάλληλων μεταλλικών κέντρων και συνδετών, ενώ η καταλυτική τους δράση μπορεί να ενισχυθεί μέσω ενσωμάτωσης δομών άνθρακα ή/και οξειδίων μετάλλων

Visual analytics in healthcare education: exploring novel ways to analyze and represent big data in undergraduate medical education

Introduction. The big data present in the medical curriculum that informs undergraduate medical education is beyond human abilities to perceive and analyze. The medical curriculum is the main tool used by teachers and directors to plan, design, and deliver teaching and assessment activities and student evaluations in medical education in a continuous effort to improve it. Big data remains largely unexploited for medical education improvement purposes. The emerging research field of visual analytics has the advantage of combining data analysis and manipulation techniques, information and knowledge representation, and human cognitive strength to perceive and recognize visual patterns. Nevertheless, there is a lack of research on the use and benefits of visual analytics in medical education.Methods. The present study is based on analyzing the data in the medical curriculum of an undergraduate medical program as it concerns teaching activities, assessment methods and learning outcomes in order to explore visual analytics as a tool for finding ways of representing big data from undergraduate medical education for improvement purposes. Cytoscape software was employed to build networks of the identified aspects and visualize them.Results. After the analysis of the curriculum data, eleven aspects were identified. Further analysis and visualization of the identified aspects with Cytoscape resulted in building an abstract model of the examined data that presented three different approaches; (i) learning outcomes and teaching methods, (ii) examination and learning outcomes, and (iii) teaching methods, learning outcomes, examination results, and gap analysis.Discussion. This study identified aspects of medical curriculum that play an important role in how medical education is conducted. The implementation of visual analytics revealed three novel ways of representing big data in the undergraduate medical education context. It appears to be a useful tool to explore such data with possible future implications on healthcare education. It also opens a new direction in medical education informatics research

Research Progress in Metal-Organic Framework Based Nanomaterials Applied in Battery Cathodes

Metal-Organic Frameworks have attracted profound attention the latest years for use in environmental applications. They can offer a broad variety of functions due to their tunable porosity, high surface area and metal activity centers. Not more than ten years ago, they have been applied experimentally for the first time in energy storage devices, such as batteries. Specifically, MOFs have been investigated thoroughly as potential materials hosting the oxidizing agent in the cathode electrode of several battery systems such as Lithium Batteries, Metal-Ion Batteries and Metal-Air Batteries. The aim of this review is to provide researchers with a summary of the electrochemical properties and performance of MOFs recently implemented in battery cathodes in order to provide fertile ground for further exploration of performance-oriented materials. In the following sections, the basic working principles of each battery system are briefly defined, and special emphasis is dedicated to MOF-based or MOF-derived nanomaterials, especially nanocomposites, which have been tested as potential battery cathodes

Key Points of Advanced Oxidation Processes (AOPs) for Wastewater, Organic Pollutants and Pharmaceutical Waste Treatment: A Mini Review

Advanced oxidation procedures (AOPs) refer to a variety of technical procedures that produce OH radicals to sufficiently oxidize wastewater, organic pollutant streams, and toxic effluents from industrial, hospital, pharmaceutical and municipal wastes. Through the implementation of such procedures, the (post) treatment of such waste effluents leads to products that are more susceptible to bioremediation, are less toxic and possess less pollutant load. The basic mechanism produces free OH radicals and other reactive species such as superoxide anions, hydrogen peroxide, etc. A basic classification of AOPs is presented in this short review, analyzing the processes of UV/H2O2, Fenton and photo-Fenton, ozone-based (O3) processes, photocatalysis and sonolysis from chemical and equipment points of view to clarify the nature of the reactive species in each AOP and their advantages. Finally, combined AOP implementations are favored through the literature as an efficient solution in addressing the issue of global environmental waste management

Curriculum Mapping with Academic Analytics in Medical and Healthcare Education.

No universal solution, based on an approved pedagogical approach, exists to parametrically describe, effectively manage, and clearly visualize a higher education institution's curriculum, including tools for unveiling relationships inside curricular datasets.We aim to solve the issue of medical curriculum mapping to improve understanding of the complex structure and content of medical education programs. Our effort is based on the long-term development and implementation of an original web-based platform, which supports an outcomes-based approach to medical and healthcare education and is suitable for repeated updates and adoption to curriculum innovations.We adopted data exploration and visualization approaches in the context of medical curriculum innovations in higher education institutions domain. We have developed a robust platform, covering detailed formal metadata specifications down to the level of learning units, interconnections, and learning outcomes, in accordance with Bloom's taxonomy and direct links to a particular biomedical nomenclature. Furthermore, we used selected modeling techniques and data mining methods to generate academic analytics reports from medical curriculum mapping datasets.We present a solution that allows users to effectively optimize a curriculum structure that is described with appropriate metadata, such as course attributes, learning units and outcomes, a standardized vocabulary nomenclature, and a tree structure of essential terms. We present a case study implementation that includes effective support for curriculum reengineering efforts of academics through a comprehensive overview of the General Medicine study program. Moreover, we introduce deep content analysis of a dataset that was captured with the use of the curriculum mapping platform; this may assist in detecting any potentially problematic areas, and hence it may help to construct a comprehensive overview for the subsequent global in-depth medical curriculum inspection.We have proposed, developed, and implemented an original framework for medical and healthcare curriculum innovations and harmonization, including: planning model, mapping model, and selected academic analytics extracted with the use of data mining

Key Points of Advanced Oxidation Processes (AOPs) for Wastewater, Organic Pollutants and Pharmaceutical Waste Treatment: A Mini Review

Advanced oxidation procedures (AOPs) refer to a variety of technical procedures that produce OH radicals to sufficiently oxidize wastewater, organic pollutant streams, and toxic effluents from industrial, hospital, pharmaceutical and municipal wastes. Through the implementation of such procedures, the (post) treatment of such waste effluents leads to products that are more susceptible to bioremediation, are less toxic and possess less pollutant load. The basic mechanism produces free OH radicals and other reactive species such as superoxide anions, hydrogen peroxide, etc. A basic classification of AOPs is presented in this short review, analyzing the processes of UV/H2O2, Fenton and photo-Fenton, ozone-based (O3) processes, photocatalysis and sonolysis from chemical and equipment points of view to clarify the nature of the reactive species in each AOP and their advantages. Finally, combined AOP implementations are favored through the literature as an efficient solution in addressing the issue of global environmental waste management