Τμήμα Επιστήμης & Μηχανικής Υλικών
Παρουσίαση Διδακτορικής Διατριβής κ. Αντωνίου Κόρδα
17 Οκτωβρίου 2023
Επιβλέπουσα: Ανθή Ρανέλλα
(Σύμφωνα με το άρθρο 95, παρ. 3 του Ν. 4957/2022, ΦΕΚ 141 τ. Α΄/21.7.2022)
Την Τρίτη 24 Οκτωβρίου 2023 και ώρα 10:30 στην αίθουσα Β2 του Τμήματος Χημείας του Πανεπιστημίου Κρήτης, θα γίνει η δημόσια παρουσίαση και υποστήριξη της Διδακτορικής Διατριβής του υποψήφιου διδάκτορος του Τμήματος Επιστήμης και Τεχνολογίας Υλικών κ. Αντωνίου Κόρδα, με θέμα:
«3D Scaffolds for Neural Regeneration»
Περίληψη
“Disease and trauma are primary causes of damage and malfunction of the Nervous System (NS). Tissue Engineering (TE) is a field that aims to alleviate such issues and develop strategies to repair damaged tissues. TE utilizes scaffolds that mimic the native tissue and provide substrates for cell cultures that would later be introduced to the damaged site and restore function.
To restore NS, the basic concept of TE is often combined with other strategies such as co-culture of multiple cell types and electrical stimulation (ES). The combination of scaffolds fabricated via Two-Photon Polymerization and the co-culturing of glial Schwann (SW10) and neuronal N2a cells revealed the interactions between the two cell lines in the in vitro experiments in order to develop an in vitro experimental model for PNS studies. The co-culture environment was favorable for the growth of longer neurites for extended experimental periods over the respective N2a cultures and scaffold topography affected axon directionality, highlighting the benefits of scaffolds and co-culture environments towards N2a differentiation. Furthermore, ES was applied to NE-4C stem cells cultured on flat glasses and simple groove arrays to study the different cell fates towards neurons or glial cells in CNS recovery. NE-4C cells formed neurospheres which developed tracts that were influenced by groove topography while astrocytes (glia) were also present. Additionally, the use of specific markers for both neurons and glia revealed the effect of ES on the expression of said markers, towards the understanding of NE-4C behavior and development of functional neuronal networks.”
Παρουσίαση Διδακτορικής Διατριβής κ. Χρυσάνθης-Πηνελόπης Αποστολίδου
17 Οκτωβρίου 2023
Επιβλέπουσα Καθηγήτρια: Άννα Μητράκη
(Σύμφωνα με το άρθρο 95, παρ. 3 του Ν. 4957/2022, ΦΕΚ 141 τ. Α΄/21.7.2022)
Την Δευτέρα 23 Οκτωβρίου 2023 και ώρα 12:00 στην αίθουσα Τηλεεκπαίδευσης Ε130 του Τμήματος Μαθηματικών και Εφαρμοσμένων Μαθηματικών του Πανεπιστημίου Κρήτης, θα γίνει η δημόσια παρουσίαση και υποστήριξη της Διδακτορικής Διατριβής της υποψήφιας διδάκτορος του Τμήματος Επιστήμης και Τεχνολογίας Υλικών κ. Χρυσάνθης-Πηνελόπης Αποστολίδου, με θέμα:
«Responsive Self-Assembled Peptide Biomaterials and Applications»
«Αποκρίσιμα Αυτοοργανωμένα Πεπτιδικά Βιοϋλικά και Εφαρμογές»
Περίληψη
“Smart biomaterials" are designed to respond to external stimuli like light, pH, and metals, offering diverse applications from bioimaging to anticancer and antimicrobial applications. Peptides are highlighted as promising components for these materials due to their self-assembly properties, biocompatibility, and bio-functionality. This dissertation investigates peptides in three contexts: first, as a light-responsive delivery system encapsulating porphyrins to create antimicrobial hydrogels, analyzing structure, mechanics, and antimicrobial properties. Second, peptides are used to chelate fluorescent molecules for cancer cell bioimaging, with successful coordination and cell penetration. Finally, biocompatible peptide-metal ion nanoparticles are explored for antibacterial and anticancer purposes, revealing their potential in tumoral environments. The study overall explores smart biomaterial development, focusing on peptides and their responsiveness to external stimuli.”
Πρόσκληση και Πρόγραμμα Τελετής Υποδοχής Πρωτοετών Φοιτητών
16 Οκτωβρίου 2023
Δείτε τη συνημμένη πρόσκληση και το πρόγραμμα για την υποδοχή των πρωτοετών φοιτητών του Τμήματος Επιστήμης και Τεχνολογία Υλικών, η οποία θα πραγματοποιηθεί την Τετάρτη 18-10-2023 και ώρα 11:00.Παρουσίαση Διπλωματικής Εργασίας της φοιτήτριας κ. Μαργαρίτας Λούσα
11 Οκτωβρίου 2023
Πέμπτη 26/10/2023 και ώρα 12:00
στην αίθουσα Ε102 του Κτηρίου Τμήματος Μαθηματικών και Εφαρμοσμένων Μαθηματικών
Θέμα Διπλωματικής:
«Ab-initio insights on adsorption on ZnO surfaces doped with Mn»
Διμελής Επιτροπή: Ιωάννης Ρεμεδιάκης, Γεώργιος Κοπιδάκης
Abstract:
Zinc Oxide (ZnO) is a wide-bandgap semiconductor material that has been extensively studied due to its unique electronic and optical properties, which play a crucial role in a variety of applications such as rubber, adhesives, pigments, batteries and main different catalytic applications to mention just a few. Moreover, adsorption is a well known aspect in catalysis and in some cases the degree of adsorption can also be used as an indicator of the catalytic activity of a material. The main focus on this thesis will be the simulation of molecular adsorption on ZnO surface slabs doped with Mn. Simulations of adsorption on Mn-doped ZnO surfaces, can provide important insight into the catalytic properties of the material and aid in the development of more efficient and selective catalysts. We consider adsorption of model molecule such as CO and H on its surface. We focus on the adsorption energy and in particular, how it depends on adsorption site and Mn content. The simulations are performed using the Vienna Ab-initio Simulation Package (VASP), one of the most widely used in the field of computational materials science, which performs first-principles electronic structure calculations using DFT (Density Functional Theory).
ΑΞΙΟΛΟΓΗΣΗ ΑΙΤΗΣΕΩΝ ΓΙΑ ΣΙΤΙΣΗ ΚΑΙ ΣΤΕΓΑΣΗ ΧΩΡΙΣ ΕΚΚΡΕΜΟΤΗΤΕΣ,ΤΩΝ ΝΕΟΕΙΣΕΡΧΟΜΕΝΩΝ ΠΡΟΠΤΥΧΙΑΚΩΝ ΦΟΙΤΗΤΩΝ ΣΧΟΛΩΝ ΗΡΑΚΛΕΙΟΥ, ΑΚΑΔ. ΕΤΟΥΣ 2023-2024
11 Οκτωβρίου 2023
Δείτε τη σχετική ανακοίνωση στη σελίδα της Φοιτητικής Μέριμνας.PhD student position at IESL
11 Οκτωβρίου 2023
In view of the forthcoming start of the HORIZON-EIC-2023-PATHFINDEROPEN-01-01 Project Glas-A-Fuels, entitled “Single-Atom Photocatalysts Enhanced by a Self-Powered Photonic Glass Reactor to Produce Advanced Biofuels”, we are looking to recruit a PhD student for the duration of four years. The experimental work will be implemented in the ULMNP laboratory of IESL-FORTH, while the provisional starting date would be February or March 2024. The main research activities will involve the synthesis, patterning, and characterization of functional composite inorganic oxide glasses.
The applicants are kindly asked to provide their CV to Dr. I. Konidakis (ikonid@iesl.forth.gr) and Dr. E. Stratakis (stratak@iesl.forth.gr).
Requirements:
B.Sc. and M.Sc. in physical sciences (Chemistry, Physics, Materials Science).
Useful links
FORTH: https://www.forth.gr/
IESL-FORTH: http://www.iesl.forth.gr/
ULMNP: http://stratakislab.iesl.forth.gr/ and https://www.iesl.forth.gr/en/research/ULNMP-Group
Παρουσίαση Διδακτορικής Διατριβής κ. Γεωργίου Βαϊλάκη
11 Οκτωβρίου 2023
Πρόσκληση σε Δημόσια Παρουσίαση της Διδακτορικής Διατριβής του
κ. Γεωργίου Βαϊλάκη
Επιβλέπων Καθηγητής: Γεώργιος Κοπιδάκης
(Σύμφωνα με το άρθρο 95, παρ. 3 του Ν. 4957/2022, ΦΕΚ 141 τ. Α΄/21.7.2022)
Την Πέμπτη 19 Οκτωβρίου 2023 και ώρα 10:00 στην αίθουσα Τηλεεκπαίδευσης Ε130 του Τμήματος Μαθηματικών και Εφαρμοσμένων Μαθηματικών του Πανεπιστημίου Κρήτης, θα γίνει η δημόσια παρουσίαση και υποστήριξη της Διδακτορικής Διατριβής του υποψήφιου διδάκτορος του Τμήματος Επιστήμης και Τεχνολογίας Υλικών κ. Γεωργίου Βαϊλάκη , με θέμα:
«Theoretical Study of Two-Dimensional Nanostructures.»
Περίληψη
“Intensive research efforts on two-dimensional (2D) materials of atomic thickness uncover interesting phenomena, exciting physics, and new possibilities for technological innovation. 2D materials show great promise in electronics, optoelectronics, sensing, catalysis, clean energy and environment applications. Following semimetal graphene (Gr), focus is on other stable 2D materials with varying electronic properties such as insulating hexagonal boron nitride (hBN), semiconducting transition metal dichalcogenides (TMDs), and superconducting iron selenide (Fe2Se2). The electronic properties of these materials are strongly affected by strain, nanostructuring, structural and chemical defects, and disorder. Layer by layer stacking of 2D materials gives rise to van der Waals heterostructures (VDWHs) of nanometer thickness and clean interfaces. Superconductivity of twisted bilayer Gr at the magic angle, interlayer excitons in TMD heterostructures and optoelectronic properties of Gr/TMD heterostructures, are examples, among others, where VDWHs significantly differ from their monolayer (ML) constituents. 2D nanostructures often exhibit extraordinary properties and present novel challenges for theory. Theoretical models can answer emerging fundamental questions and identify candidate materials with properties tailored for specific applications from all the range of unique 2D nanostructures. First-principles calculations, which provide solution to the quantum problem and are the basis for atomic-scale understanding of materials, become challenging when deviations from periodicity are strong.
In this work, we perform density functional theory (DFT) calculations for the atomic and electronic structure of defected 2D nanostructures, heterostructures consisting of combinations of TMD MLs, Gr, and other materials. Due to the large size of the simulation cells required, DFT calculations are very demanding and the results need careful interpretation using non-trivial computational tools. We present in detail the methods we develop for the construction of optimized simulation cells and for unfolding the electronic band structures from their Brillouin Zone (BZ). The effective band structure (EBS) produced allows for a clear and direct comparison between electronic properties of 2D defected nanostructures and heterostructures with their pristine or constituent MLs.
Applying our methodology to Gr/TMD and TMD/TMD heterostructures, several experimental observations are explained and predictions are made. Interlayer interactions in Gr/TMD have negligible effects. The Dirac cone of Gr remains unaffected, variations in the TMD electronic band gap are due to the minimal strain remaining in the simulation cells, and Fermi levels move closer to the conduction band minimum. In WX2/MoX2 VDWHs, where X = S, Se, interactions between TMD MLs result in hybridization of electronic states and energy eigenvalues split around the center of the BZ (Γ point). The magnitude of energy splitting depends on the interlayer distance and determines the valence band maximum at the center or the edge (K point) of the BZ. We find that interlayer transitions are more probable in WSe2/MoSe2 than in WS2/MoS2. In all VDWHs we examined, a small but universal redshift of the band gap for the TMDs is observed as opposed to a small blueshift for the Au/MoS2 heterostructure, in agreement with experiments. In hBN/TMD VDWHs, electronic properties of constituent MLs remain unaffected.
Our methodology also proves very useful in investigating defects and adsorption on 2D MLs. In conjunction with experiments, our DFT calculations show how n-doped WSe2 ML becomes a p-doped semiconductor via photochlorination. Energetics and EBSs show that chlorine fills chalcogen vacancies, neutralizing defect states close to the conduction band minimum and creating defect states close to valence band maximum. In another synergy with experiment, our DFT calculations show that Fe-vacancies in Fe2Se2 MLs give rise to a stretched lattice (which remains superconducting) at a relatively low energy cost. The absolute magnetic moment of the Fe atoms near the vacancies increases. Our EBS calculations demonstrate the effects of Fe vacancies in agreement with experiments. Sinking of the hole pocket and creation of new states above the hole pocket and below the electron pocket are produced by Fe vacancies. Finally, we present our theoretical results for hydrogen adsorption on Ni2P/CuCo2S4 heterostructure within another collaboration with experimentalists. Electron transfer towards the CuCo2S4 is related to the superior performance of the heterostructure as a catalyst for hydrogen evolution reaction.
Our DFT-based studies with the methodology we developed for building simulations and interpreting electronic band structures, combined with data from experiments, besides explaining observed phenomena, provide a general framework for making predictions which should be useful in future experiments and applications.”
Παρουσίαση Διπλωματικής Εργασίας της φοιτήτριας κ. Ειρήνης Κολιού
11 Οκτωβρίου 2023
Πέμπτη 26/10/2023 και ώρα 10:00
στην αίθουσα Φ2 του Κτιρίου Τμήματος Φυσικής
Θέμα Διπλωματικής:
« Εφαρμογές Οπτικής Φασματοσκοπίας στην Μελέτη Καυσίμων »
Διμελής Επιτροπή: Δημήτριος Παπάζογλου, Πέτρος Σαμαρτζής
Περίληψη:
Στην παρούσα εργασία χρησιμοποιούνται τεχνικές οπτικής φασματοσκοπίας στην μελέτη υγρών καυσίμων. Συγκεκριμένα, μέσω μετρήσεων φασματοσκοπίας απορρόφησης UV-NIR, FTIR, Raman και φθορισμού, επιχειρούμε τον χαρακτηρισμό μιγμάτων ναυτιλιακού καυσίμου (blends) ως προς την σταθερότητά τους καθώς και την ανίχνευση νοθείας σε καύσιμα κίνησης με χημικούς διαλύτες. Η εξαγωγή πληροφορίας από τα φασματοσκοπικά δεδομένα γίνεται με την χρήση μεθόδων στατιστικής ανάλυσηςΠαρουσίαση Διπλωματικής Εργασίας της Μ. Μεταξά
11 Οκτωβρίου 2023
Παρουσίαση Διπλωματικής Εργασίας
της φοιτήτριας Μαρίας Μεταξά
Τετάρτη 18 Οκτωβρίου 2023 και ώρα 13:00,
στην αίθουσα Α210
στο κτήριο του Τμήματος Μαθηματικών και Εφαρμοσμένων Μαθηματικών του Πανεπιστημίου Κρήτης.
Διμελής Επιτροπή: εράσιμος Αρματάς, Κωνσταντίνος Μήλιος