PhD students
According to Greek law the names of all PhD students, their advisors and advisory committees, titles of the dissertations and a short abstract are posted on the department's website.The list in the Greek language can be found here.
Alafogianni Panagiota
Dissertation title
Study on dispersion, environmental response and durability of nano-composite construction materialsAdvisor
Barkoula Nektaria-MarianthiAdvisory committee
| Matikas Theodoros | Dassios Konstantinos | |
| DMSE | DMSE |
Abstract
In this PhD dissertation, the dispersion of carbon nanotubes (CNTs) in aqueous solutions is studied by means of ultrasonic agitation and dispersing agents such as surfactants and cement plasticizers. The dispersion quality is assessed by Liquid Mode Laser Diffractometry (LMLD) and UV-Vis Spectroscopy. The parameters investigated are: duration of sonication, dispersive agent/ CNT ratio and sonication power. In the next step, laboratory-scale structures are manifactured based on optimal CNT dispersion parameters to investigate the effect of nanomodification and intense environmental loading on the following properties of structures: (a) Transport properties (water absorption, gas permeability), (b) Chloride penetration, (c) Mechanical properties / Structural integrity, (d) Monitoring abilities / damage detection via acoustic emission. The expected results are: Indicators of transport properties (water absorption coefficient / gas permeability coefficient, as a function of CNT content and dispersive agent). The chloride penetration study determines the effect of environmental exposure on penetration depth and chloride diffusion coefficient. Mechanically, the effect of environmental exposure on flexion, compression and toughness is determined, while through acoustic emission, it is investigated how basic parameters of acoustic behavior of materials alternate after environmental exposure.
Anastasiou Athanasios
Dissertation title
Flow Properties of Magnetic Nano-fluids in Porous Media using Nuclear Magnetic Resonance (NMR) MethodsAdvisor
Karakassides MichaelAdvisory committee
| Fardis Michael | Jamal Hassan | |
| NCSR DEMOKRITOS | Khalifa University |
Abstract
The objective of this PhD thesis is the development and application of new Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI) methods in a systematic study of flow properties of magnetic nano-fluids in porous media. Due to the complexity of the porous structure, particularly in heterogeneous materials with pore sizes stretching over several orders of magnitude, the exact theoretical description of the porous system cannot be obtained. Moreover, the introduction of the magnetic forces, due to magnetic nano-fluids, further complicates the experimental realization as well as the theoretical investigation of the mass transfer of the dispersions within the porous media. In order to overcome this weakness of the detailed description of mass transport phenomena, we use NMR, and MRI measuring the nuclear spin of the fluid molecules (hydrogen nuclei present in fluids). These techniques provide important information about the molecular dynamics of both bulk fluid and fluid constrained in small pores. An example of the capabilities of these methods is the precise measurement of self-diffusion coefficient of bulk fluid by NMR in external magnetic field gradients. This measurement can also be made to fluids constrained in porous materials for obtaining valuable information regarding the random walk of the fluid molecules within the interconnecting pores of the porous material and characterizing the pore structure by determining the pore size distribution.
Andrea Maria
Dissertation title
Research and simulation of electonic and optical properties of graphene and application in opto-electronic and plasmonic devices.Advisor
Papageorgiou DimitriosAdvisory committee
| Lidorikis Elefterios | Kopidakis George | |
| DMSE | Department of Materials Science and Technology, University of Crete |
Abstract
There is a growing attention of the research community for organic optoelectronic materials due to their use in a wide range of applications and their low cost. Organic semiconducting polymers belong to this type of materials, as well as graphene, due to the hexagonal lattice of carbons. The current dissertation focuses on the electronic model of these materials and the study of physical parameters that affect charge transport. Our goal is to study and improve mobility of carriers. Several composite structures will be investigated in terms of geometric and energy features as well as how these features affect electronic and optical properties. For this purpose, a computational study will be performed, based on Density Functional Theory, for molecules and for large periodic systems. The aim of this dissertation is to study the mechanism of (opto)electronic properties of novel organic molecules, in order to be used in organic photovoltaic cells, organic light-emitting diodes (OLEDs) etc.
Asimakopoulos Georgios
Dissertation title
Carbon based nanoporous materials with sorbent and catalytic propertiesAdvisor
Karakassides MichaelAdvisory committee
| Gournis Dimitrios | Bourlinos Athanasios | |
| DMSE | Physics Dept UOI |
Abstract
The proposed research focuses on some of the most up-to-date and promising developments in the field of carbon-based hybrid mesoporous materials and is supported by specialized material characterization techniques and by methods of controlling their functionality in technological applications that are nowadays . Research will focus on the development of mesoporous carbon hybrid systems. In this PhD dissertation, a synthesis of nanoporous materials based on carbon, their characterization and their assessment for energy and environmental applications will be carried out. In the first part of the experiments a composition of porous carbon nanostructures with organized and non-structured carbon structures will be carried out, emphasizing the use of natural renewable sources of carbon such as used coffee, glucomannan and others. Then these nanostructures will be modified by the development of magnetic nanoparticles on the surface and / or inside of their pores. At the same time, they will be characterized by advanced techniques. The final leg will assess their magnetic properties and test their functionality by testing these advanced materials in applications such as polluted water purification and targeted drug delivery.
Aza Eleni
Dissertation title
Strongly correlated Transition Metal Oxides: Synthesis, Structure, Magnetic, Dielectric and Dynamical properties.Advisor
Panagiotopoulos IoannisAdvisory committee
| Lappas Alexandros (1st co-supervisor) | Douvalis Alexios | |
| FORTH | Physics Dept UOI |
Abstract
The discovery of materials with coexisting magnetic and ferroelectric orders, namely magnetoelectrics, has revived the interest of condensed matter physics in materials science communities. More precisely it challenged the design of systems where electric and magnetic orders could be strongly coupled maintaining the great promise of such fundamental mechanisms in devising applications ranging from portable magnetoelectric (ME) sensors and memories to radar technologies. The present PhD dissertation wishes to uncover such highly sought material-systems where fundamental studies could be pursued. It focuses on the synthesis and characterization of layered transition metal oxides aiming to the better understanding of strongly correlated phenomena where coupled properties arise from the interplay of charge and spin degrees of freedom over lattice topologies which enable competing magnetic interactions. For this study different polymorphs of Na-Mn-O system have been developed inspired by the intrinsic geometrical frustration of the triangular lattice of the Mn cations which may lead to a variety of magnetic and magneto-electric phenomena. The focus is put in the more extended study of dielectric and magneto-electric properties of polycrystalline specimens of the aforementioned system together with dynamical magnetic properties. For the first time growth of large single crystals of this system is pursued giving the opportunity to unravel a different magnetic evolution of the system using single crystal neutron diffraction.
Ballaxhia Claudi
Dissertation title
Modeling mechanical, electrical & magnetic properties of composite and multifunctional materials.Advisor
Gergidis LeonidasAdvisory committee
| Paipetis Alkiviadis | Nektaria Barkoula | |
| DMSE | DMSE |
Abstract
The purpose of the present study is the investigation of mechanical, electrical and magnetic properties of composite and multifunctional materials.In the present work atomistic-molecular simulations with known interaction potentials of the literature will be used for the calculation of the aforementioned properties .
Baltzis Dimitrios
Dissertation title
Durability of Composite Materials reinforced in a multiscale levelAdvisor
Paipetis AlkiviadesAdvisory committee
| Nektaria Marianthi Barkoula | Aggeliki Lekatou | |
| DMSE | DMSE |
Abstract
This PhD research is concerned with the multi-scaled modification of epoxies via the inclusion of selected nano-, micro- and macro-scaled reinforcing phases. The studied nano- and micro- scaled reinforcements include carbon fillers like Multi Walled Carbon Nano Tubes (MWCNTs) and Carbon Black (CB) while the macro-scaled reinforcements include Carbon and Glass fibres. All nano- and micro- scaled fillers are dispersed using high speed shear mixing protocols which will be optimized according to the respective filler type or types and weight contents. The inclusion of the macro-scaled reinforcing fibres, will be conducted by employing vacuum and hot-press assisted hand lay-up resulting to hybrid fibre reinforced composites (HFRCs). In order to fully understand the reinforcing phases effect on the final material properties, a series of mechanical, rheological and durability assessment experimental procedures are to be followed. The mechanical tests will include fracture toughness, tensile strength, Dynamic mechanical analysis and mode-I interlaminar fracture, tensile strength and flexural tests for the matrix level and the HFRCs level. The rheological experimental procedures will be applied at the matrix level throughout the dispersion procedures so as to study the fillers inclusion effect on the rheological properties. Selected mechanical tests will be combined with hydrothermal exposure protocols for the durability assessment. The results from all experimental procedures will be combined in order to develop a model that could accurately predict the mechanical properties of the HCFRCs.
Bardis Konstantinos
Dissertation title
Development of Non-Destructive Technique for the Structural Health Monitoring of Materials and StructuresAdvisor
Dassios KonstantinosAdvisory committee
| Theodore Matikas | Patricia Vázquez Menendez | |
| UOI | Université de Reims Champagne-Ardenne, France |
Abstract
Control of the structural integrity of materials and structures is directly related to recent developments in the field of Non-Destructive Evaluation (NDE). In order to efficiently design, maintain and manage building materials, information about their structural condition is essential knowledge. To this end, fast, reliable and cost-effective MSE methodologies are becoming increasingly necessary in the various areas of human activity. In the present study, we will study the development of NDE methods to control the structural integrity of materials and structures through innovative non-destructive infrared thermography, acoustic emission and ultrasonic techniques. To achieve that, specialized non-destructive damage detection systems will be developed to assist in the development of advisory methodologies to optimize the mechanical response of the materials and structures under study.
Boukis Filippos
Dissertation title
Compact membrane reactor combined with novel membrane in intensification systems to produce low-cost hydrogen from biogas (CO COMMERCIAL)Advisor
Beltsios KonstantinosAdvisory committee
| Karakassides Michael | Athanasekou Chrysoula | |
| DMSE | NCSR ''DEMOKRITOS'' |
Abstract
Hydrogen is considered globally as the fuel of the future, given its environmental advantages over conventional fossil fuels, which are the main source of pollutant gases (CO 2, NO x, SO x). Methane (CH4) is converted to hydrogen through the classic Steam Methane Reforming process. At high temperatures (700-1100 ° C), in the presence of a nickel catalyst, the water vapor reacts with methane to carbon monoxide and hydrogen (CH 4 + H 2 O ? CO + 3 H 2). Further hydrogen production can be achieved if the CO produced is then reacted with water vapor via the water gas swift reaction (CO + H 2 O ? H 2 + CO 2) in the presence of a copper or iron catalyst. In the present study, low cost permeability ceramic membranes will be studied to achieve the appropriate selectivity of products to produce pure hydrogen with minimal impurities (CO <10 ppm). The final mixture of hydrogen and carbon dioxide is separated through a hybrid ionic / ceramic substrate hybrid membrane to separate CO 2 from the exhaust gas mixture of the previous two reactors. The appropriate ceramic substrate and the appropriate ionic liquid will be selected to maximize CO2 removal.
Chalkia Vasiliki
Dissertation title
Synthesis, Characterization and Modification by the Gel-Casting Method of Advanced Ceramic MaterialsAdvisor
Avgeropoulos ApostolosAdvisory committee
| Stathopoulos Vasileios | Karakassides Michael | |
| Technological Educational Institute of Sterea Ellada, School of Technological Ap | DMSE |
Abstract
The development of research and technology has resulted in the growing development of ceramic materials for existing and future applications. Applications are directly dependent on the synthesis and formatting process. The limitations of classic molding methods such as fluid casting and plastic molding (eg injection molding) have led to an alternative method of shaping complex shapes, gel-casting. The gel-casting method is a promising molding method as it combines features of traditional processes such as injection molding and liquid casting with polymer chemistry. In this process, a high concentration of ceramic powder suspension is added to a monomer solution and polymerized in situ by means of a certain amount of primer. This creates the green body, which is then molded into suitable molds. Here is the process of removing the organic substances by heating and finally the heat treatment of the sample to produce the final product. Due to the production of complex shapes and exceptional properties, the process resonates in a variety of applications such as nuclear reactors and aerospace.
Chalmpes Nikolaos
Dissertation title
Development and study of novel two dimensional nanostructures for technological applicationsAdvisor
Gournis DimitriosAdvisory committee
| Karakassides Michael | Bourlinos Athanasios | |
| DMSE | Physics Dept UOI |
Abstract
Graphene, a 2D layered carbon nanomaterial has been the subject of intense interest among the scientific community due to its numerous applications. The synthesis of organic, inorganic or organic-inorganic molecules, almost unrestrictedly, with the desired structure and functionality, in combination with the technology of thin film deposition and self-assembly, allows the production of electrical , optical and biologically active materials and devices in the nanoscale level. This will be conducted using a) Langmuir-Blodgett technique, which allows the development of multilayered hybrid nanostructures with a variety of hosted materials as well as b) the layer-by-layer (LbL) deposition process in which alternating layers of oppositely charged materials are deposited in a substrate. The aim of this dissertation is the design, development and study of novel hybrid thin films based on two-dimensional inorganic nanostructures, concentrating their usage in specific technological applications. Significant emphasis will be attributed to the development and exploration of the properties of novel layered inorganic nanostructures, such as germanane, germanene, (analogue of graphene), silicene as well as other exotics 2D nanostructures (eg MoS2, TaS2).
Choleva Evangelia
Dissertation title
Nanostructured adsorbents and membranes for biogas refining and upgrade via H2S capture and CO2/CH4 separation processesAdvisor
Beltsios KonstantinosAdvisory committee
| Evangelos Chatzigeorgiou | Dimitrios Papagiannis | |
| DMSE | DMSE |
Abstract
The main goal of this project is the development of a new innovative and economically feasible process for the upgrading of the biogas to biomethane grade fuel through the removal of its two main pollutants, H2S and CO2. The approach that is proposed as the alternative to the prevailing upgrade methods comprises of (a) an adsorption step for the H2S removal followed by (b) a membrane stage for enriching (in methane) of the desulfurized biogas. Significant emphasis will be attributed to the research and development of new functionalized carbon nanomaterials for the H2S adsorption, able to achieve sorption capacity values higher than 8.0 mmol H2S/g sorbent; and on the fabrication of hybridic NF/IL membranes for the CO2/CH4 separation, with 6:1 selectivity and 3500 Barrer permeability in CO2 at relative low pressures (5-10 bars).
Chroneou Evangelia
Dissertation title
Mathematical and computational simulation for the hydrodynamics of Lake PamvotisAdvisor
Kalpakides VassiliosAdvisory committee
| Charalampos Tsakmakis | Evangelos Hadgigeorgiou | |
| Darmstadt (Germany) | Materials Science and Engineering Department |
Abstract
Mathematical and computational simulation for the hydrodynamics of Lake Pamvotis
Cutrano Carla
Dissertation title
Computational design of functional Fe- and Cu- based coatings for environmentally sustainable applicationsAdvisor
Lekka ChristinaAdvisory committee
| Dimitris Papageorgiou | Georgios Evangelakis | |
| DMSE | Physics Dept UOI |
Abstract
This PhD thesis deals with the study of structural, electronic, magnetic properties of surfaces/coatings and nanoclusters having Fe or Cu. The target is to design materials with non-toxic substitutions which they will have high magnetic properties, corrosion resistance and hydrophobic properties. This research work is part of the european project H2020-MSCA-ITN-2014 (?o: 642642), entitle «Smart ELECTrodeposited Alloys for environmentally sustainable applications: from advanced protective coatings to micro/nano-robotic platforms».
Dagkli Alkmini-Vasiliki
Dissertation title
Enhanced light-matter interactions and optoelectronic devices based on grapheneAdvisor
Lidorikis ElefteriosAdvisory committee
| Papageorgiou Dimitrios | Spyridon Kaziannis | |
| Department of Materials Science and Engineering | Physics Department University of Ioannina |
Abstract
Monolayer transition metal dichalcogenide (TMD) semiconductors, with direct bandgaps of visible to near infrared ranges (NIR), make them promising candidates for light generation. In this thesis, we study and model optoelectronic devices based on flexible 2D materials, as 2D LEDs based on TMDs and graphene. Recently, light emitting 2D vertical structures, such as graphene/h-BN/WSe2 and graphene/h-BN/MoS2 tunneling junction LEDs were developed showing low external quantum efficiency (EQE), when placed on top of a standard SiO2/Si substrate. Thus, it is necessary to enhance the EQE of TMD-based LEDs using resonant cavities (RCLEDs), with metallic mirrors or dielectric Bragg reflectors, and photonic crystal cavities (PhCLEDs). Furthermore, we study 2D LEDs inside waveguides for applications in fast and directly modulated integrated photonics. We model different cavity designs using finite-difference time-domain (FDTD) method and calculate the radiative emission rate of 2D LEDs, the Purcell enhancement factor, the extraction efficiencies, the internal and external quantum efficiencies and substrate losses. With the appropriate choose of materials and TMD-graphene based LED geometrical parameters, we can fine-tune the emission of light and enhance the emission intensity and directionality of emitted light, in order to be able to compete the conventional OLEDs.
Dalla Panagiota-Aikaterini
Dissertation title
Study of Mechanical and Electrical Behavior of Nano-Reinforced Multifunctional Construction MaterialsAdvisor
Matikas TheodorosAdvisory committee
| Mparkoula Nektaria-Marianthi | Dassios Konstantinos | |
| DMSE | DMSE |
Abstract
?any researchers deal with cement-based materials because of their good durability and strength. Nanostructures such as graphene, carbon nanotubes and carbon nanofibers are advanced inclusions that give important properties to cement materials, making the final product "smart" and multifunctional. The aim of this thesis is the addition of an electrically conductive carbon-based mixture to reduce the electrical resistance of a cementitious mixture, the ability to detect potential damage to the structure in real time, to enhance its mechanical and thermal properties and its resistance to environmental stress conditions on a laboratory scale. The second part of this thesis deals with the degradation of metallic materials and alloys by electrochemical corrosion and the creation of targeted pits in the specimen, with the ultimate aim of developing an integrated methodology related to the electrochemical corrosion of metallic materials and the determination by means of the mechanical fatigue test and the use of infrared thermography and acoustic emission of the fatigue limit of any kind of strained metallic material compared to vergin specimens. At the same time, the visual study and evaluation of surface characteristics of materials using white light interferometry is a useful tool that completes the multi-faceted study of materials.
Dimitriadis Konstantinos
Dissertation title
Desighn, synthesis and characterization of novel glasses and glass-ceramics in the system R2O-CaO-MgO-SiO2-P2O5-TR2O3 (R:Li, Na, K, TR: B2O3, Al2O3) for applications in dentistryAdvisor
Agathopoulos SimeonAdvisory committee
| Karakassides Michael | Dilshat Tulyaganov | |
| Department of Materials Science and Engineering | Turin Polytechnic University in Tashkent |
Abstract
New glasses and glass-ceramic materials, with novel compositions in the R2O-CaO-MgO-SiO2-P2O5-TR2O3 (R: Li, Na, K, and TR: B2O3, Al2O3,) system, will be produced aiming in the technology of dentistry. The glasses will be produced by melting technique in platinum crucibles and quenching in order to obtain glass frit. Full characterization of glasses will be conducted, such as density measurements, Raman and FT-IR spectroscopy, thermal analysis, etc. Glass-ceramics will be produced by the sintering technique and controlled crystallization of glass-frit powder compacts. Full characterization of glass-ceramics will comprise density measure-ments, X-ray diffraction, Raman and FT-IR spectroscopy, thermal analysis, microstructure observations, and evaluation of mechanical properties. Bioactivity tests will be carried out in simulated body fluid at 37 oC. The results will be analyzed in order to qualify the investigated compositions in specific applications in modern dental clinical practice, such as dental implants, or fixed all-ceramic prosthetic restorations.
Doukas Spyridon Chrysovalantis
Dissertation title
Study and simulation of graphene based photonic devices from NIR to FIRAdvisor
Lidorikis ElefteriosAdvisory committee
| Papageorgiou Dimitrios | Kopidakis George | |
| DMSE | Department of Materials Science and Technology, UoC |
Abstract
Graphene, a 2D hexagonal lattice of carbon atoms has attracted the attention of the scientific community since its discovery in 2004. Its monoatomic thickness, along with its unique band – structure, makes it a perfect candidate for a large amount of different applications. A lot of those applications are falling in the field of photonics. The aim of this dissertation is to explore the usage of graphene in a wide range of photonic devices such as photodetectors, modulators, chemical sensors et.c. This will be done using standard computational photonics methods (Finite Difference Time Domain, Transfer Matrix Method et.c) as well as computational tools that are going to be developed during this thesis. The first target is to integrate graphene with the current state – of – the – art technologies (i.e. Silicon Photonics). At the same time, novel designs consisting from the combination of graphene and other 2D materials such as MoS2, WSe2 and hexagonal – BN will be investigated. These so called Van – der – Waals heterostructures are one of the hottest topics in condensed matter physics and materials science and are expected to find application in areas such as flexible electronics.
Exarchos Dimitrios
Dissertation title
Characterization of advanced materials deterioration in aged structures with non- destructive methods of thermographyAdvisor
Matikas TheodorosAdvisory committee
| Moropoulou Antonia | Dassios Konstantinos | |
| NTUA | UOI |
Abstract
The characterization of the wear of advanced materials in aging structures is very important in the whole range of constructions (infrastructure, aerospace, automotive, etc.). The aim of this thesis is the development of new advanced infrared thermography methodologies for the evaluation of wear in all the aforementioned constructions. More specifically, advanced techniques were developed for the non-destructive assessment of aircraft structures, cement-based materials, phononic metamaterials, composite materials, as well as cultural heritage monuments. Also, a new infrared thermography method using peltier thermoelectric elements to characterize sub-surface imperfections in a range of different materials is being developed. Moreover, the Lock-in thermography method was further developed to rapidly estimate more accuretely the fatigue limit using a single specimen.
Floros Ioannis
Dissertation title
Development and optimization of innovative membranes and hybrid desalination systemsAdvisor
Hadjigeorgiou EvangelosAdvisory committee
| Beltsios Konstantinos | Fokas Dimosthenis | |
| DMSE | DMSE |
Abstract
The aim of this project is to develop a “next-generation” of desalination system upon combination of innovative membranes to ? membrane-distillation/membrane-crystallization (MD/MCr) unit involving nanofiltration (NF) and/or ultrafiltration (UF); the target is a novel desalination unit exhibiting low energy consumption and minimum fouling problems. The implementation of the goal of this research will be achieved as a result of combination of the outcome of the following optimization and development activities: 1. Development of novel high water flux Aligned Carbon Nanotube (ACNT) Membrane Distillation (MD) membranes. 2. Development of novel forward osmosis (FO) and nanofiltration (NF) Mixed Matrix Membranes (MMM) that have the form of two-layer hollow polymeric memrbanes and include a graphene oxide/CNT nanocomposite separating layer. 3. Modeling and optimization the action of the membrane units. 4. Integration, operation and optimization of the NF/FO and MD membranes to develop a low pressure operating system with Zero or near-zero Liquid Discharge (ZLD). 5. The construction of a small laboratory pilot scale unit with a capacity of 1 m3/day and a low power consumption of the order of 0,5 kWh / m3.
Foteinidis Georgios
Dissertation title
Smart micro- and nano-composites: non destructive evaluation of production and /or response to various loadingsAdvisor
Paipetis AlkiviadesAdvisory committee
| Barkoula Nektaria Marianthi | Gergidis Leonidas | |
| DMSE | DMSE |
Abstract
Structural Health Monitoring is a vital tool enabling on-line damage detection and topography on epoxy matrix reinforced composites. Among several SHM techniques, the ones related with the electrical response to damage are capable of providing information about the structural degradation of the material with high sensitivity and precision. The aim of this dissertation is the conversion of a conventional composite into a multifunctional material to provide crucial information for Structural Health Monitoring (SHM). A specific lamination sequence of carbon and glass fabrics in combination with a ternary epoxy matrix will offer SHM topography capabilities. The matrix reinforcement will be consisted of homogenously dispersed Carbon Nanotube and Carbon Black. A sinusoidal electric field will be applied between the established local capacitors using Impedance Spectroscopy technique. The layout of the laminas will enable the damage assessment after medium velocity impact. Hence, the damaged area will be depicted in 2D and 3D contour topographical images which will reveal useful information about the structural integrity of the composite. Additionally, the integration of self-healing capabilities will be studied in order to achieve the manufacturing of a smart composite with wide range of functionalities.
Georga Eleni
Dissertation title
Development of Physiological Metabolic Models in Diabetes Based on Data Mining TechniquesAdvisor
Fotiadis DimitrisAdvisory committee
| Likas Aristidis | Charalambopoulos Antonios | |
| Dept. of Computer Science & Engineering, University of Ioannina | School of Applied Mathematical & Physical Sciences, National Technical Universit |
Abstract
The prediction of the short-term course of subcutaneous glucose concentration in individuals with type 1 diabetes is a research problem that has been widely studied, particularly, since the adoption of continuous glucose monitoring and continuous subcutaneous insulin infusion in the daily management of the disease. In this PhD dissertation, the dynamic system of blood glucose metabolism is approximated by nonlinear, with respect to the input, regression techniques of machine learning aiming at representing its intrinsic nonlinearity and non-stationarity. Kernel-based regression models, combined with mathematical (compartmental, mechanistic) models of the kinetics of exogenous materials (i.e. subcutaneously administered insulin, carbohydrates ingestion and absorption), were efficiently used for this purpose. Novel nonlinear recursive frameworks to the online identification and prediction of the dynamic glucose system in type 1 diabetes, taking advantage of sparse kernel adaptive filtering (KAF), were additionally investigated. Using a multivariate dataset obtained under everyday living conditions, we demonstrated that both short term and mostly long term (i.e. for 60 min and 120 min) predictions become significantly more accurate and safe in critical glucose regions of hypoglycaemia and hyperglycaemia when extra inputs are used, and we featured the efficacy of sparse KAF in dynamic learning of subcutaneous glucose concentration course.
Gioti Christina
Dissertation title
Theoretical and experimental study of structure and properties of phosphate glasses with transition elementsAdvisor
Papayannis DimitriosAdvisory committee
| Karakassides Michael | Koutselas Ioannis | |
| DMSE | Department of Materials Science |
Abstract
Glasses constitute a wide and severally important part of ceramic materials. Structurally they are amorphous, non-crystalline solids produced by quenching supercooled liquids and fusion products of inorganic crystalline compounds that were rapidly cooled and solidified. These materials, and particularly phosphate glasses, exhibit unique optical and physical properties such as high thermal expansion coefficient and low melting point, higher than silicate glasses, but their use is limited due to their low chemical durability and their tendency for corrosion under extreme conditions, such as humidity. Taking into consideration the above mentioned, phosphate glass systems are selected to be prepared and studied (as the name suggests, P2O5 is the main glass former), incorporating transition metal oxides, such as MnO, FeO, CuO, as glass modifiers. The different potential valences of the transition metals into the glass structure was the milestone, taking into consideration the modification of the phosphate network, affecting significantly their properties. This study approaches both an experimental and theoretical framework, correlating experimental results with quantum mechanical calculations and molecular dynamics in parallel. This dissertation focuses on a comparative study of the structure and the properties of novel high-stability phosphate glass systems, and their potential use in many technological applications.
Giousis Theodosis
Dissertation title
Design, development and study of novel 2D materials beyond grapheneAdvisor
Gournis DimitriosAdvisory committee
| Karakassides Michael | Bourlinos Athanasios | |
| DMSE | Physics Dept UOI |
Abstract
Graphene is a carbon nanostructured material with numerous applications, which is considered by the research community as one of the most interesting and promising nanomaterials. The isolation of graphene sparked a real breakthrough in materials science, while the discovery of other nanocarbon forms such as fullerenes, carbon dots, carbon nanotubes and the wide variety of properties (electric, thermal, magnetic, engineers) that accompanies these materials have expanded the range of applications in various fields such as the construction of sensors, conductive inks, drug delivery, the development of various electronic circuits and in the production composite materials. In fact, the discovery and exploitation of graphene properties opened the way for exploring and understanding the properties of inorganic 2D materials. The number of two-dimensional materials is enormous and includes significant categories of materials The main objective of this thesis is synthesis and study of novel functional (or/and multifunctional) hybrid materials beyond graphene which are expected to be used in a wide range of applications such as energy storage, eterogeneous catalysis, gas separation, nanosensors, electronic applications and to the development of innovative composite polymers. The formation of these hybrid materials is based on 2D materials such as germanane, silicane, transition metal dichalcogenides and 2D oxides. These materials will be prepared using old and new synthetic protocols including top- down and bottom – up techniques. These two-dimensional materials will be suitably modified with organic and / or inorganic molecules in order to change their physicochemical properties. In addition, these materials chemically modified or not will be combined with each other or with other nanomaterials such as organic molecular materials, nanoparticles, organic or inorganic nanostructures, in order to create new nanostructures. This dissertation aims on the synthesis of novel hybrid or/and nanoporous materials for a wide range of applications, but mainly aimed at energy, environmental and catalytic applications.Synthetic methods used for the growth of hybrid materials include insertion reactions, sol-gel, hydrothermal synthesis, solid state reactions and thin film formation by the Langmuir-Blodgett technique. From a scientific and technological point of view, these materials will be an extremely important achievement for applications in the field of nanotechnology, i.e. energy, environment, chemical industry, health, electronics, etc.
Ioannou Koulla
Dissertation title
Computational study of biocompatible materialsAdvisor
Lekka ChristinaAdvisory committee
| Dimitris Papageorgiou | Eleytherios Lidorikis | |
| DMSE | DMSE |
Abstract
This PHd work deals with the study of the structural, electronic, magnetic and mechanical properties of biocompatible materials. Special emphasis will be given in the Ti-based alloys while the target is to design materials using bio-friendly substitutions with low Young modulus and high hardness compared to the human bones.
Ioannou Chrysoula
Dissertation title
Development and study of the Life Cycle Analysis of Building Strustures in GreeceAdvisor
Matikas TheodorosAdvisory committee
| Paipetis Alkiviadis | Barkoula Nektaria | |
| DMSE | DMSE |
Abstract
In Greece, the main material used in construction is concrete. This material is produced from aggregates, cement and water without any special impurities or special materials. All materials to be used in construction as concrete, steel, bricks, insulation and individual materials will be studied in terms of their properties, their production and the built-in energy they contain until they reach the construction site but also their environmental footprint. In addition, two conventional structures will be compared, one of reinforced concrete as a bearing body and the other one by metal frame. The aim is to compare the materials involved in the construction, to create a database with their energy balance from their production to the point of use, while assessing their environmental footprint in order to obtain proposals for replacing the mentioned materials with materials with less production energy and more environmentally friendly.
Kaklamanis Konstantinos
Dissertation title
Computational study of charge transport in organic optoelectronic materials and devicesAdvisor
Papageorgiou DimitriosAdvisory committee
| Lekka Christina | Lidorikis Elefterios | |
| DMSE | DMSE |
Abstract
Organic semiconductors are a promising class of materials being economical and environmentally friendly. Compared to widely used inorganic semiconductors, they are flexible, light weight, their optical and electronic properties can be modified by molecular design and are compatible with scalable manufacturing processes. Furthermore, organic semiconductors have demonstrated significant applicability in organic light emitting diodes (OLED), organic thin film transistors (OTFT), and organic solar cells (OSC). In the proposed doctoral dissertation, the effect of microstructure on the diffusion and mobility of the carriers will be studied, in the case of conjugated polymers used in organic photovoltaic devices or in the case of small organic molecules used in OLED and OTFT applications. Amorphous or semicrystalline structures will be used, obtained from coarse grained molecular dynamics simulations of the systems under consideration or from experimental data. The rate of hops of carriers will be determined by quantum-mechanical calculations or empirical models, while the main equation will be solved using Kinetic Monte Carlo simulation techniques. The final aim of this dissertation is to establish a relation between the microstructure of the materials and their electrical properties in order to optimize them.
Karalis Georgios
Dissertation title
Development of technologies for thermoelectric energy harvesting with embedded multifunctional properties from advanced composite materialsAdvisor
Paipetis AlkiviadesAdvisory committee
| Gournis Dimitrios | Gergidis Leonidas | |
| DMSE | DMSE |
Abstract
Multifunctional structural composites are an extremely interesting research field in advanced building materials technology because beyond the structural functions (high mechanical strength with reduced specific weight) they offer individual capabilities for simultaneous implementation of various non-structural functions such as structural integrity monitoring, temperature control, deformation or damage detection, storage, harvesting and energy generation. Given the urgent need for alternative forms of energy, thermoelectric power generators promise major applications in converting the commonly lost thermal energy into electricity. The nanostructures with the high thermoelectric efficiency developed due to their two-dimensional nature are virtually impossible to apply directly to large-scale structures. Thus, in order to exploit their unique properties, their incorporation into three-dimensional materials is required. This PhD dissertation will focus on the targeted research effort to improve the Seebeck coefficient of the carbon fibers which is the reinforcing phase through hierarchical nanostructures so that the ability of the final polymer matrix composite structures to have additional functional properties of the thermoelectric generator (Thermoelectric Element Generator-TEG) for the purpose of energy harvesting, exploiting the thermoelectric effect.
Karouta Niki
Dissertation title
Nanosized hybrid superstructures: Synthesis, characterization and study of propertiesAdvisor
Gournis DimitriosAdvisory committee
| Karakassides Michael | Georgakilas Vasilios | |
| DMSE | Material Science Dep., UP |
Abstract
Synthesis and study of novel functional (or/and multifunctional) hybrid superstructures based on carbon nanomaterials, which are expected to be used in a plethora of applications such as gas storage, gas separation, as nanosensors, in nanoelectronic devices and also for drug delivery and bioimaging systems. Hybrid superstructures are defined as the merge of different carbon nanostructures with novel and improved properties for various technological applications. Hybrid superstructures will be synthesized by using carbon nanomaterials such as graphene and its derivatives (graphene oxide, carbon nanodiscs, and intercalated graphite compounds) as well as new carbon structures like carbon nanodots, and hierarchical carbon. These nanomaterials will be used combined with each other or with other nanostructures such as organic molecular materials, nanoparticles, layered inorganic materials, etc. in order to form advanced nanoarchitectures with advanced and controllable properties. The synthetic methods that will be used for the development of the hybrids include intercalation reactions, sol-gel processing, hydrothermal synthesis, solid state reactions and formation of thin films using the Langmuir-Blodgett technique. From a scientific and technological point of view, these materials will constitute a highly important achievement for applications in the field of nanotechnology, and more specifically for energy sector, in environmental remediation, chemical industry, health, and electronics.
Karydis-Messinis Andreas
Dissertation title
Development and characterization of polymer hydrogel scaffolds for biomedical applicationsAdvisor
Zafeiropoulos NikolaosAdvisory committee
| Avgeropoulos Apostolos | Fotiadis Dimitrios | |
| DMSE | DMSE |
Abstract
Biocompatible composite materials have gained a prominent place in polymer science and technology because of their widespread use in biomedical applications. In the present thesis two groups of materials are going to be prepared. The first group of materials concerns the preparation of scaffolds composed of fish collagen, chitosan and chondroitin sulfate (Col / Ch / CS), while the second group concerns scaffolds with the natural polymers from the first phase combined with polycaprolactone microspheres (Col / Ch / CS / PCL MPs), with the ultimate aim of improving the mechanical behavior of the materials. The predominant goal is to optimize the collagen / chitosan ratios as well as the size of the microspheres that are going to be introduced into the scaffolds. The ultimate goal is to prepare a competitive material for use as a burn healing patch.
Kordatou Theodoti
Dissertation title
Processing and Analysis of Digital and Analog Data for Nondestructive Characterization Development Methods of Materials and StructuresAdvisor
Matikas TheodorosAdvisory committee
| Gergidis Leonidas | Angelidis Pantelis | |
| UOI | University of West Macedonia |
Abstract
In recent years, the damage assessment has become very attractive as it provides non-contact, non-destructive, accurate and improved evaluation of advanced materials and structures. The aim of this PhD thesis is the development of advanced algorithm and software based on LabVIEW in order to enable accurate and automated measurements of acoustic activity. ?his automated method was applied for real-time damage detection in specimens undergoing cyclic mechanical loading. In addition, the possibility of automation of the method was considered. Specifically, the possibility of two-way communication between the laboratory equipment, as well as the control and the operation through a single console are investigated. The second part of the dissertation deals with the development of an automated method for evaluating the level of material damage due to high cycle fatigue. Finally, the third part of the dissertation deals with the development of an automated method by means of acoustic microscopy, using Matlab code, in order to evaluate the level of material degradation and to define damage matrics parameters.
Kosarli Maria
Dissertation title
Novel concepts for optimizing the self-healing processes in advanced aerospace composite structures.Advisor
Paipetis AlkiviadesAdvisory committee
| Avgeropoulos Apostolos | Kontou - Drougka Evagelia | |
| DMSE | School of Applied Mathematical and Physical Sciences, National Technical Univers |
Abstract
Fiber Reinforced Polymers (FRPs) are among the most important technological materials in the industrial and research communities due to their excellent specific properties. Their excellent modulus of elasticity in combination with the relatively low density and corrosion resistance are some of the FRPs desirable properties. However, the FRPs relatively low fracture toughness can result to undesirable fracture phenomena that could compromise the materials structural integrity. The approach of self –healing materials expands the current conventional damage tolerance or/and repair approaches and has attracted significant attention in the research community the last decade. The scope of this PhD research is to develop and optimize a self-healing approach and integrating the SH technology into FRPs. The roadmap for the investigation and integration of the proposed SH approach includes (i) the selection of the self-healing approach, (ii) the selection of FRPs matrix material, (iii) development of a SH-FRP material and (iv) the manufacturing of a demonstrating structure with SH-capabilities.
Kotanidis Alexios
Dissertation title
Computational study and design of nanostructured surfaces for applications in optoelectronic devices.Advisor
Lidorikis ElefteriosAdvisory committee
| Patsalas Panagiotis | Sigalas Mihail | |
| Physics Dept AUTh | DMS UOP |
Abstract
Light trapping is one of the most important considerations in photovoltaic device design. In crystalline silicon (c-Si) solar cells, reflections from the top cell surface can be reduced by texturing and by applying anti-reflection coatings on the surface. Conversely, the back surface can also be textured to increase light scattering and trapping. In this PhD thesis we present a comprehensive computational study of various texturing designs of both the c-Si top and back surfaces, involving pyramid textures, plasmonic nanostructuring, and dielectric gratings and find the designs that yield improved light absorption and current generation. Also Nano-structuring of metals is one of the greatest challenges for the future of plasmonic and photonic devices. Such a technology calls for the development of ultra-fast, high-throughput and low cost fabrication techniques. Also In this thesis we investigated theoretically the photo-thermal processes involved in surface and sub-surface plasmonic nano-structuring. To this end, we present a design process and develop functional plasmonic nano-structures with pre-determined morphology by tuning the annealing parameters like the wavelength.
Kyriaki Tsirka
Dissertation title
Study of the graphitic reinforcement of hierarchical epoxy matrix composites.Advisor
Paipetis AlkiviadesAdvisory committee
| Gournis Dimitrios | Papanicolaou George | |
| DMSE | MEAD |
Abstract
In the context of this PhD dissertation, graphitic hierarchical structures were studied which are used as secondary reinforcements in fiber-reinforced polymer composites with structural applications and multi-functionalities. More specifically, hierarchical reinforcing structures were developed by i) growing multi-wall carbon nanotubes (CNTs) via catalytic chemical vapor deposition; and ii) depositing CNTs from aqueous suspensions / inks on the carbon fiber surface. The work was divided into two axes. The first axis focused on the synthesis and optimization of hierarchical reinforcements and the extensive characterization of their structure and morphology through a variety of analytical technics. The second axis targeted the study of the mechanical properties of the hierarchical fibers and the properties of the interfaces formed between them and the epoxy matrix. The study of the mechanical properties of the interface of the hierarchical composites was carried out using Raman spectroscopy and mechanical tests on model composite materials. Overall, the present work, following a biomimetic approach, studied the synergies between the different graphitic structures that constitute hierarchical carbonaceous reinforcements and demonstrated their dual nature as bearing and multifunctional elements, which is enhanced through the hierarchy of their structure.
Lambrou Eleftherios
Dissertation title
Development of mathematical and computational models for the investigation of materials under mechanical, electric-magnetic or thermal fields.Advisor
Gergidis LeonidasAdvisory committee
| Charalambopoulos Antonios | Paipetis Alkiviadis | |
| SEMFE: School of Applied Mathematical and Physical Sciences, NTUA | DMSE |
Abstract
The aim of this work is the development of mathematical and computational models for the study of materials under mechanical, electromagnetic or thermal fields. The behavior and the response of materials under simple or coupled fields will be studied using continuous models solved with finite elements methodology . The study of the response of materials to the aforementioned fields is important for the design of new materials with desirable properties.
Manesi Gkreti-Maria
Dissertation title
Macromolecular Architecture: Synthesis, characterization and Properties of Linear and Non-Linear Copolymers of Polystyrene and Poly(dimethylsiloxane) for nanotechnology applicationsAdvisor
Avgeropoulos ApostolosAdvisory committee
| Zafeiropoulos Nikolaos | Sakellariou Georgios | |
| DMSE | Chemistry Department UOA |
Abstract
Anionic polymerization through high vacuum technique in combination with chlorosilane chemistry will be used. Synthesis of star and mikto-arm copolymers with poly(dimethylsiloxane) will be accomplished. Molecular weights will be such that satisfactory structure / property relationships arise with the main objective of studying the dependence of properties on architecture. The synthesized samples will be molecularly characterized through Osmometry, Dynamic Light Scattering, 1H-NMR, viscometry. Morphological characterization will be accomplished via Transmission Electron Microscopy and Scanning Electron Microscopy, Small Angle X-Ray Scattering (SAXS). A rheological study of the final samples will be performed to determine their viscoelastic behavior and the ability to determine the transition temperature from disorder to order for low molecular weight samples of polystyrene and poly(dimethylsiloxane). Finally, Scanning Probe Microscopy (SPM), Energy Filtering Transmission Electron Microscopy (EFTEM) and Electron Tomography Transmission Electron Microscopy (EMTEM) experiments will be carried out to study the deposition of polymers on suitable substrates in order to examine their behavior before and after chemical modifications, e.g. removal of one or more blocks by ozonolysis, UV radiation, ion-exchange etching, etc.
Mathiou Christina
Dissertation title
Development and characterization of novel high entropy alloy systems with two or more phasesAdvisor
Karantzalis AlexandrosAdvisory committee
| Lekatou Angeliki | Matikas Theodoros | |
| DMSE | DMSE |
Abstract
The subject of this dissertation is based on High Entropy Alloys (HEAs), the introduction of which has opened a new research field, setting new perspectives on the development of novel metallic materials. These alloys present a promising combination of properties that makes them possible candidates for replacing some of the most commonly used conventional alloys and superalloys in high demanding applications. In particular, high entropy alloys contain at least 5 principal elements at equimolar or near-equimolar atomic percentages (5-35 at.%) and ideally constitute of single phase solid solutions. However, both the fact that the ability to form single phase solid solutions when more than five elements are present is limited and the need for a more sufficient balance of properties has steered researches’ interest towards high-entropy alloys with two or more phases. Towards this direction, the discovery of the most suitable combination of elements and their concentrations in order to receive HEAs with two or more phases with improved properties and microstructural characteristics will be attempted. Additionally, recognizing the enormous usefulness of studying the properties of these alloys, the mechanical, tribological and corrosion properties will be examined using appropriate and up-to-date techniques. The results to be exported are believed to reinforce the existing literature.
Melissovas Sofoklis
Dissertation title
Development of innovative cementing recipes for cementing surface casing across unconsolidated sands in deep-water wellsAdvisor
Karakassides MichaelAdvisory committee
| Dimtrios Gournis | Theodoros Martikas | |
| University of Ioannina | University of Ioannina |
Abstract
Development of innovative cementing recipes for cementing surface casing across unconsolidated sands in deep-water wells
Miskaki Christina
Dissertation title
Macromolecular Architecture: Synthesis, characterization and properties of copolymers and terpolymers for applications in nanotechnologyAdvisor
Avgeropoulos ApostolosAdvisory committee
| Zafeiropoulos Νikolaos E. | Gournis Dimitrios | |
| DMSE | DMSE |
Abstract
With the demand of nanotechnology for low-dimensions (sub-10nm), new linear triblock terpolymers will ne synthesized, with relatively low molecular weights (<Mntot>= 10,000 and 15,000 g/mol respectively), of the A-b-B-b-C and B-b-A-b-C type. A is poly(butadiene) (PB), B polystyrene (PS) block and C poly(dimethylsiloxane) (PDMS). In the above samples, the PB block will display either a high microstructure of -1.4 (~ 92%) or a high microstructure of -1.2 (~ 100%). The well-studied diblock copolymers PS-b-PDMS show strong microphase separation as it is possible to control the organization and thickness of their thin films on various surfaces due to the high interaction parameter Flory-Huggins, ?. The low molecular weight PB block is inserted to avoid the use of PS-OH or PDMS-OH homopolymers for polymeric brushes, as reported in the literature, for the adhesion / adsorption of diblock thin films on suitable surfaces (usually silicon). Therefore, the PB will be modified by hydroboration / oxidation reactions, aiming at direct adhesion to the thin film substrate, and depending on the location of the PB block the organization of the remaining two blocks (PS and PDMS) will be studied in order to finally have sub-10 nm nanostructures for nanotechnology applications.
Mourkas Angelos
Dissertation title
Study of reversal and dynamic of magnetism in nanomaterials with controllable anisotropyAdvisor
Panagiotopoulos IoannisAdvisory committee
| Bakas Thomas | Gergidis Leonidas | |
| Physics Department | DMCE |
Abstract
The current magnetism roadmap emphasizes on vortex-like excitations in ferromagnets called “magnetic skyrmions” which, due to their topological stability, are very promising as information carriers for applications in non-volatile memories and logical devices. Their vortex-like structure offers inherently built four-state logic based on the core (up/down) and chirality (left/right) states. The stabilization of skyrmions is based on the DMI in systems, lacking inversion symmetry. This dissertation focuses on the optimization broken symmetry multilayers of the form Pt/Co/X (?=W,Mo,Ta) in order to combine perpendicular anisotropy and strong interfacial Dzyaloshinskii–Moriya interaction (DMI) contribution, in order to establish effect of chirality induced by DMI on their dynamic response and spin-wave propagation properties and evaluate their performance with respect room-temperature skyrmion stabilization and non-reciprocal magnonics, as these spin-orbit-coupling emergent phenomena permit the realization of alternative spin-wave based information technologies.
Mourlas Athanasios
Dissertation title
Comparative evaluation of deposits and properties of ceramic and composite materialsAdvisor
Karakassides MichaelAdvisory committee
| Psyllaki Pandora | Vourlias George | |
| University of West Attica, Faculty of Engineering, Mechanical Engineering Depart | Aristotle Unoversity off Thessaloniki,Faculty of Sciences, Physics Department |
Abstract
In this dissertation, the feasibility of using Concentrated Solar Power (CSP) technology was investigated for the in-situ elaboration of composite surface layers onto steel base metal. CSP technology was evaluated for producing metallic matrix composites with carbide particles reinforcement, as an alternative to laser surface modification technique. In this aim, “solar” experiments were carried out in the solar furnace FS40, at the installations of Plataforma Solar de Almería (Spain). Carbide-based powders (TiC, WC and Cr2C3) were pre-deposited onto carbon steel and subsequently exposed to concentrated solar irradiation for various dwell time values. The produced composite surface layers were examined by the aid of optical microscopy, in order to define the values range of treatment parameters, for which surface layers free of pores and cracks were achieved. An extensive microstructure examination via scanning electron microscopy and X-ray diffraction allowed distinguishing the behavior of the three different types of carbide particles in the molten steel pool during exposure and re-solidification. Microhardness values of the metallic matrix were evaluated according to Lee and Gurland model, commonly applied to cermets. Finally, sliding wear tests were performed, in order to evaluate in-service performance and machinability of the elaborated hardfacings, respectively. Based on these experimental results, the proposed technique was compared to Flux Cored Arc Welding (FCAW), to which it exhibits many fundamental commonalities.
Moutsios Ioannis
Dissertation title
Synthesis and Characterization of Diblock Copolymers and Triblock Terpolymers for Nanotechnology ApplicationsAdvisor
Avgeropoulos ApostolosAdvisory committee
| Lidorikis Eleftherios | Gioti Maria | |
| DMSE | Physics Department AUTH |
Abstract
Synthesis and characterization (molecular-morphological) of polymers will be accomplished. Samples of A-b-B and A-b-B-b-C types will be synthesized, where functionallity will be evident either on A or B or C block depending on degment type and/or chemical modification reactions. The segments should show different Flory-Huggins interaction parameter ? in order to microphase separate in well-defined nanostructures. The synthesized samples will be molecularly characterized through Osmometry, Dynamic Light Scattering, 1H-NMR, viscometry. Morphological characterization will be accomplished via Transmission Electron Microscopy and Scanning Electron Microscopy, Small Angle X-Ray Scattering (SAXS). Finally the use of the aforemnetioned copolymers and terpolymers for nanotechnology applications will be studied, such as: nanolithographic masks and assymetrical nanoporous polymeric membranes.
Mouzourakis Eleftherios
Dissertation title
Production of Nanomaterials with Flame Spray Pyrolysis for Environmental & Catalytic TechnologiesAdvisor
Deligiannakis Ioannis (InterdeparmentalAdvisory committee
| Bakas Thomas | Gournis Dimitris | |
| Dept. Physics, Univ. of Ioannina | DMSE, UoI |
Abstract
Semiconducting nanooxides and suboxides ?consitiute a family ogf nanomaterials with a great potantial in technological applications such as oxidative catalysis and photocatalysis. The scalable production of such nanmaterials having high purity, high crystallinity, controlable size and composition is the subject of the present PhD Thesis using Flame-Spray Pyrolysis (FSP) technology. The PhD candidate works on the deveompnet of the FSP reactor and optinisation of the process parameters towards targeted nanooxides and suboxides foe environmental catalytic applications. The so produced materials will be characterised by XRD, BET, TEM as well as EPR, FTIR, DRS, Raman spectroscopies and magnetic and other pertinent physicochemcial methods. Their catalytic perforrmance will be studied for ?2 production and photocatlsysis.
Mytafides Christos
Dissertation title
Smart coatings for targeted functionalities in advanced structural composite materialsAdvisor
Paipetis AlkiviadesAdvisory committee
| Gournis Dimitrios | Gergidis Leonidas | |
| DMSE | DMSE |
Abstract
The great breakthroughs of smart materials and nanotechnology in the past decades, has emerged as a particularly promising route in the field of advanced composite materials. The biomimetic approach of nanostructured interfaces for hierarchical composites (micro-scale reinforcing fibers coated with nanoparticle-based layers) to Carbon Fiber Reinforced Polymers (CFRPs), exhibiting impressive durability and multifunctionality (simultaneously mechanical and electrical properties, including high mechanical strength, energy harvesting & self-diagnostic capability). The innovation of this PhD thesis is related to the fact that, apart from the materials engineering to tailor the smart coatings final properties endowed to the reinforcement and to the laminate 3D composites, the structural character will be also considered. Furthermore, optical (photo-sensing properties), thermal (thermoelectric energy harvesting) and piezo/mechanical fields (strain sensors and/or piezoelectric energy harvesting) will be mainly investigated, as well as the mechanism that the multifunctional composite is responding in bulk will be investigated in detail. The ultimate foundation character of this PhD is the realization of all the functionalities at a demonstrator structure/device level that will be able to show the functionality upon being exposed to the specific field.
Orfanidis Savvas
Dissertation title
Development and study of novel advanced composite material simulating the operation environment .Advisor
Paipetis AlkiviadesAdvisory committee
| Papavasiliou Georgios | Evagelos Xristoforou | |
| NCSR Demokritos INN | NTUA ECE |
Abstract
A wide range of advanced composite materials, polymers reinforced with glass or carbon fibers, are used as light weight, high strength and high corrosion resistance reinforcing structures. These materials are widely used in transportation: terrestrial (buses, trains), marine (yachts and boats) and aerospace (parts of the shaft and wings). Such materials during their operation function under dynamic loads, continuous vibrations, fatigue, external forces, deformations and harsh environmental conditions. In such environments, there is a need to periodically evaluate the structural integrity in a non-destructive technique in order to avoid dangerous anomalies such as laminar detachment, breakage of fibers, cracks,etc.An innovative method for operating quality control of the structure is guiding waves because they can travel long distances on structures where they consist of flat metal substrates without significant attenuation. Guiding waves can therefore respond to large areas of inspection or control from a remote location with a relatively small number of non-destructive evaluation (NDE) or structural health monitoring (SHM) ).The main objective of the present study will be the effect of the microstructure on the mechanical behavior of the composite materials in order to optimize their mechanical and elastic properties. The experimental study will be implemented through non-destructive testing techniques, ultrasound and Nuclear Magnetic Resonance (NMR) spectroscopy.
Papadopoulos Theofilos
Dissertation title
Surveillance and modeling of Heart Failure using sensors and biosensorsAdvisor
Fotiadis DimitrisAdvisory committee
| Papaloukas Konstantinos | Naka Ekaterini | |
| DBAT UOI | Faculty of Medicine UOI |
Abstract
Although the patho-physiology of Heart Failure has been understood in great extent by the medical community, it is asymptomatic at least in early stages and its severity estimation is subjectively evaluated. Machine Learning techniques that after training recognize patterns in the data and make predictions automatically , can support experts in their decision. N?vel techniques of Artificial Intelligence as deep learning allows a machine to be fed with raw data to automatically extract features from the data and to make internally representations with multiple levels of abstraction , needed for detection or classification.The multilevel architecture enables the discovering of intricate structures and the learning of complex functions between the input data and the classification task. The aim of this dissertation is the design and the implementation of deep learning models such as a) Convolutional Neural Networks and b) Recurrent Neural Networks in data from sensors and biosensors and deep models such as a) Deep Belief Networks b) stacked Restricted Boltzmann Machines c) Deep Autoencoders and combination of them in clinical , biological, medication and general demographic data for the early diagnosis of Heart Failure, the severity estimation of NYHA (?ew York ?eart Association) class, the prediction of patient treatment adherence and the prediction of adverse events.
Papanikolaou Anna
Dissertation title
The inverse problem of elasticity in the framework of configurational mechanicsAdvisor
Kalpakides VassiliosAdvisory committee
| Stavroulakis Georgios | Hadjigeorgiou Euaggelos | |
| Technical University of Crete | DMSE |
Abstract
The inverse problem of elasticity is the search for the undeformed state of a body, when the deformed one and the external loading have been given. It is well known that this problem will be strongly non-linear even though the direct problem is a linear one. Though, it is about a theoretical problem, there are a lot of possible applications. The setting of the problem in the framework of the so-called configurational mechanics (mechanics of the material space) will be attempted, because the unknown parameters of the latter are the position of the reference configuration, that is, the undeformed state. It is expected that in this framework the problem might be faced computationally. The almost obvious application of the problem concerns the design of a structural element, that is, to find out the optimum design of a structure when the desired shape and the applied loading during its operation are given. Moreover, the computational solution of the problem could apply, also, to phase transition problems as well as to other problems of inelasticity.
Patsouras Christos
Dissertation title
The material forces in structural design optimizationAdvisor
Kalpakides VassiliosAdvisory committee
| George Stavroulakis | Paul Steinmann | |
| Technical University of Crete | Erlangen (Germany) |
Abstract
The material forces in structural design optimization
Pezoulas Vasileios
Dissertation title
Processing and analysis of medical and other related big dataAdvisor
Fotiadis DimitrisAdvisory committee
| Gergidis Leonidas | Tzioufas Athanasios | |
| DMSE | Medical School, NTUA |
Abstract
The analysis and processing of medical and other related big data is a rapidly evolving field of interest which involves methods for data management and analysis, including artificial intelligence, machine learning, data mining and intelligent systems. An emerging scientific field of interest is data harmonization, which aims to deal with the heterogeneity of medical databases and cohorts worldwide by transforming heterogeneous datasets into homogeneous ones with minimum loss of information. Prior to data harmonization, data sharing and quality assessment issues that are posed during the data collection process are further addressed according to data protection regulations. Methods for harmonizing heterogeneous data will be examined using semantic and lexical matching tools for describing and interlinking the domain knowledge of heterogeneous data. A privacy-preserving distributed learning framework will be constructed in order to develop risk stratification models and examine biomarkers using data mining tools. The aforementioned methods will be applied on different case studies including heterogeneous clinical data from patients with different pathologies, such as autoimmune diseases, cancer, etc.
Polymerou Anastasia
Dissertation title
Advanced structural composites with architectured design for selected functionalitiesAdvisor
Paipetis AlkiviadesAdvisory committee
| Gournis Dimitrios | Galiotis Konstantinos | |
| DMSE | Chemical Engineering Technical University of Patras |
Abstract
In modern society, electronic systems and telecommunications are the most widely used technologies, as they play an important role in communication both on the earth and in space. However, electromagnetic interference (EMI) is an important issue for modern communication and electronic systems. Electromagnetic pollution is the main cause of damage to electronic devices, equipment and systems used in critical applications (eg in medicine, army, aerospace electrical systems, etc.). The causes of EMI are numerous and are due to both technical and natural sources. The subject of this PhD thesis is the study and optimization of the multi-functionality of hybrid and hierarchical composite materials. More specifically, the effect of various reinforcing phases on the efficacy of composites as electromagnetic interference (EMI shielding) materials will be studied. The incorporation of these structures into the composites will take place either by spreading them into the native phase or by placing them on the surface of the fibers (hierarchical approach). The aim is to improve the mechanical properties and to optimize the functionality of EMI shielding through the appropriate architectural design of the structure and the exploitation of specific properties of the component phases.
Rapanakis Panagiotis
Dissertation title
Computational and theoretical homogeneity in the material spaceAdvisor
Kalpakides VassiliosAdvisory committee
| Nikolaos Charalampakis | Antonis Charalampopoulos | |
| AUTH | NTUA |
Abstract
Computational and theoretical homogeneity in the material space
Roumpi Maria
Dissertation title
Development of implants for use in experimental model of the right ventricular pressure overloadAdvisor
Agathopoulos SimeonAdvisory committee
| Theofilos Kolettis | Demosthenes Fokas | |
| Department of Medicine, University of Ioannina | Department of Materials Science and Engineering, University of Ioannina |
Abstract
Pulmonary hypertension is characterized by increased pulmonary vascular resistance, causing right ventricular pressure-overload. In response to elevated wall-stress, ventricular hypertrophy is elicited, followed by progressive chamber dilatation. This complex remodeling-process eventually leads to right ventricular failure, an ominous disease-entity that portends a poor prognosis. The working hypothesis of this Ph.D. Thesis is based on the potential to intervene in the pathophysiology of right ventricular remodeling by altering wall-thickness and by decreasing wall-stress. Accordingly, the aim is to develop polysaccharide-based membranes that can mitigate remodeling after engraftment. Expanding our relevant experience on the applications of biomaterials in the left ventricle, we will fabricate a construct with mechanical properties capable of attenuating right ventricular dilatation and dysfunction. We are targeting to a membrane with an optimal elastic modulus that will effectively counterbalance the elevated wall-stress. Such constructs will be engrafted in vivo in rats with pharmacologically-induced pulmonary hypertension, according to a widely used animal-model, which displays a close resemblance with human findings. In addition to biocompatibility and biodegradability evaluation, detailed hemodynamic studies will be performed in vivo, including indices derived from pressure-volume curves. Specifically, variables describing right ventricular dimensions, as well as systolic and diastolic function will be measured, aided by the data obtained from a conductance catheter. Following these experiments, histologic measurements of right ventricular architecture will be performed. This thesis is expected to provide a deeper insight on the pathophysiology of pulmonary hypertension and its potential treatment.
Smyrlis Vasileios
Dissertation title
Modelling and computatational estimation of movement in subjects with balance disorders and investigation with sensorsAdvisor
Fotiadis DimitrisAdvisory committee
| Themis Exarchos | Leonidas Gergidis | |
| Informatics Ionian University | Materials Science and Engineering UOI |
Abstract
Balance disorders are one of the major causes of falls in patients and elderly, which are associated with serious consequences to their health and high healthcare costs. The major factors involved in balance disorders are aging, pathologies of the musculoskeletal system and the nervous system and psychological disorders. The study of balance in patients using sensors can contribute to the more accurate understanding of the interplay between the various factors in balance disorders. The results of this study may be informative to the improvement of current rehabilitation approaches or suggest new ones. The usage of a variety of sensors including IMUs and force-pressure sensors is deemed critical for finding the most effective system. Using the previous sensors, essential kinematic, kinetic and other data will be collected from patients performing specific exercises which require stability. The aforementioned data will be processed using various signal processing and machine learning techniques to assess the performance of the subjects in the exercises and assist in the assessment of the patients' balance. The previous data will also be used to develop personalized computational models of balance prediction for the patients.
Spanos michael
Dissertation title
Conjugated Polyelectrolytes: Synthesis, Proeprties Characterization and Applications in Organic Electronic DevicesAdvisor
Avgeropoulos ApostolosAdvisory committee
| Gregoriou Vasileios | Gournis Dimitrios | |
| national Hellenic Research foundation | DMSE |
Abstract
In particular, conjugated polyelectrolytes by the Stille or Suzuki type aromatic coupling technique will be synthesized using suitable palladium complex catalysts. These conjugated polyelectrolytes will consist of a hydrophobic conjugated main chain (polythiophenes, donor-acceptor type copolymers, etc.) and side chains will give a hydrophilic character such as e.g. amino groups, oligo-polyethylene glycol, sulphone groups, etc. Particular attention will be paid to: 1). Molecular chracterization with Nuclear magnetic Resonance Spectroscopy (NMR) and Size Exclusion Chromatography (SEC), 2) Optical characterization of solutions comprising conjugated polyelectrolytes in solvents of different polarity by ultraviolet visible and photoluminescent techniques, 3) Morphological characterization with transmission Electron Microscopy and Atomic Force Microscopy, 4) Study of the effect of energy levels HOMO (higher occupied molecular orbital) and LUMO (lower unoccupied molecular orbital) by the technique of circular voltammetry, 5) Applying and recording the performance of conjugated polyelectrolytes either on the active surface or as interfacial materials in organic electronic devices such as organic photovoltaics, organic light sensors etc.
Stavrou Vasileios
Dissertation title
Study of magnetic materials using micromagnetic simulationsAdvisor
Gergidis LeonidasAdvisory committee
| Charalambopoulos Antonios | Panagiotopoulos Ioannis | |
| SEMFE: School of Applied Mathematical and Physical Sciences, NTUA | DMSE |
Abstract
The purpose of the present study is the investigation of magnetization reversal in triangular and cylindrical nanoparticles using finite elements and other numerical methods in various magnetocrystalline anisotropies for different magnetic materials. Magnetization reversal features will be investigated and the underlying mechanisms will be explored to facilitate the design of new magnetic materials. In addition, topological invariants will be calculated for the quantitative description of the magnetic vortices.
Subrati Yadulla Mohammed Saleem
Dissertation title
Synthesis and characterization of nanoparticles with application for the oil and gas industryAdvisor
Gournis DimitriosAdvisory committee
| Papavassiliou Georgios | Alhassan Saeed | |
| NCSR Demokritos | Khalifa University |
Abstract
Synthesis and characterization of magnetic nanoparticles for reservoir characterization. The novel use of magnetic nanoparticles (MNPs) in the oil industry as contrast agents for reservoir characterization offers an intriguing opportunity, but at the same time it is challenging. This is due to the fact that the characteristic travel distance and residence time for those particles in the reservoirs are orders-of-magnitude greater than those in biological systems, and because reservoirs generally have much harsher conditions, such as high temperature, pressure, and salinity. In this project, we have proposed the employment of core-shell magnetic nanoparticles (CSMNPs), which are made up of bare magnetic nanoparticles (i.e. nanocores) that are dressed with hydrophilic shells capable of solubilizing the magnetic nanocores in seawater as the nanoparticles will be injected into seawater-saturated reservoirs. Core-flooding tests were performed in order to investigate the colloidal stability of the CSMNPs at high-pressure high-temperature (HPHT) conditions similar to those of the reservoir. An electromagnetic tomography (EMT) prototype system was developed, tested, and simulated using finite-element analysis techniques
Tatsis Efthymios
Dissertation title
Pavement Management System development in order to evaluate the pavement quality and optimize the recoveryAdvisor
Matikas TheodorosAdvisory committee
| Alkiviadis Paipetis | Panagiotis Papioannou | |
| DMSE | AUTH |
Abstract
The use of pavement management systems leads to significant capital savings and the correct allocation of the available resources, while maintaining the level of road service and imposing a strong influence on road safety, user costs and environmental impact. The aim of the dissertation is to study the properties of bituminous mixtures, both at study level and after paving, so that in time the resulting diagnosis of the causes leading to the appearance of the recorded surface damages and the residual lifetime can be determined. In addition, through the investigation of fatigue resistance of various types of bituminous mixtures, using modification and reinforcement materials that improve the functionality and the mechanical properties of the mixture, it will be possible to choose the appropriate material in each case. Thus, by means of an economical-technical model of the initial construction cost and the expected lifetime and maintenance costs, it will be possible to target the optimal solution according to the operating conditions and the available capital.
Thanos Christos
Dissertation title
Fabrication and Electrical characterisation of flexible resistive switching devices (RSD) by printing technologiesAdvisor
Panagiotopoulos IoannisAdvisory committee
| Alkiviades Paipetis | Eleftherios Lidorikis | |
| DMSE | DMSE |
Abstract
In the current PhD thesis, fully printed flexible RSDs will be fabricated using wet-chemical deposition techniques; mainly spin coating for the active dielectric organic layer and ink-jet printing of metal nanoparticle (NP) inks for the bottom and top electrode deposition with potential for micro-scale electrodes deposition and micro-scale devices The goal of this PhD thesis is the fabrication and electrical characterization of flexible resistive switching devices (RSDs) using mainly PMMA dielectric thin films (as well as other dielectric polymers e.g. PVP, PVDF, PS and nanocomposite systems with graphene oxide, metallic nanoparticles, etc.) sandwiched between two metallic electrodes. The RSDs are envisaged to find applications as nonvolatile memory ReRAM devices. This PhD thesis will be focused to develop fully printed flexible ReRAM devices.:In the course of the proposed PhD thesis, the electrodes could be printed or evaporated and spin coating with the active layer of PMMA and their resistive switching properties will be studied performing macroscopic current-voltage measurements and using local probes, using SEM or TEM. Gain more insight in the physical mechanisms governing these resistive switching phenomena using organic materials and fully printed RSDs. This will potentially enable the effective incorporation of ReRAM technology in commercial applications.
Thomou Eleni
Dissertation title
Design and Study of Pillared Graphenes and Nanoporous Carbon Materials for Energy, Environmental and Catalytic ApplicationsAdvisor
Gournis DimitriosAdvisory committee
| Karakassides Michael | Romanos Georgios | |
| DMSE | NCSR Demokritos |
Abstract
Synthesis and study of novel functional (or/and multifunctional) nanoporous materials based on carbon, which are expected to be used in a plethora of applications such as gas storage, heterogeneous catalysis, gas separation, as nanosensors, in electronics and as building block of novel composite polymeric materials. We envision the synthesis of hybrids based on nanostructured materials such as graphene and its derivatives (graphene oxide, carbon nanodisks, and intercalated graphite compounds) as well as new carbon structures like carbon nanodots, carbon cuboids, and hierarchical carbon. These materials, either chemically modified or not, will be combined with each other or with other nanomaterials such as molecular organic materials, nanoparticles, laminate inorganic materials to form novel hybrid materials. The synthetic methods that will be used for the development of the hybrids include intercalation reactions, sol-gel processing, hydrothermal synthesis, solid state reactions and formation of thin films using the Langmuir-Blodgett technique. From a scientific and technological point of view, these materials will constitute a highly important achievement for applications in the field of nanotechnology, and more specifically for the energy sector, in environmental remediation, chemical industry, health, and electronics.
Toulfatzis Anagnostis
Dissertation title
Characterization, cutting processes and machinability of lead-free brassesAdvisor
Paipetis AlkiviadesAdvisory committee
| David Constantine | Barkoula Nektaria-Marianthi | |
| Mechanical Engineering Department - Technological Educational Institute of Centr | Department of Materials Science & Engineering - University of Ioannina |
Abstract
In recent years, the enforced stricter regulations concerning allowable lead content levels in products, especially for drinking water applications, have encouraged the invention and utilization of innovative solutions, such as the development of lead-free brass alloys. This study was focused on the material characterization, cutting processes (chip breaking), as well as the assessment of the machinability of leaded and lead-free brass alloys, widely used in industrial applications for the fabrication of final brass component (bolts, nuts, hydraulic fittings, etc.) by machining. Initially, the influence of microstructure and lead presence on dynamic and static mechanical behaviour was studied. The main purpose of this study was the identification of the emergent microscopic fracture mechanisms, for the better interpretation of cutting behaviour during brass rods’ turning. In addition, a statistical non-parametric study was implemented for the improvement of the quality characteristics of machining process (Chip Morphology, Power Consumption, Cutting Force and Surface Roughness) of the studied alloys. Finally, a first attempt was pursued pertaining to the redesign of the production process flow, via the realization of experimental heat treatment procedures, which were applied for the alteration of microstructure in order to improve the machinability of the studied brass alloys.
Tragazikis Ilias
Dissertation title
Non-Destructive Characterization of Mechanical / Environmental Degradation of Nano-Composite Construction Materials using Acoustic TechniquesAdvisor
Matikas TheodorosAdvisory committee
| Moropoulou Antonia | Mparkoula Nektaria-Marianthi | |
| NTUA | DMSE |
Abstract
Nanotechnology is widely used in aircraft industry, electronics and construction. The purpose of this thesis is to produce cementitious materials reinforced with graphene, carbon nanotubes and nanofibres in order to improve and investigate these properties. Bending and compressive strength and their fracture toughness were examined using at the same time the method of acoustic emission under load and digital image correlation. In addition, a study was conducted to measure the ultrasound velocity in cementitious materials both during the hardening for the change monitoring of elastic properties and after the completion of the mechanism. During the maturation of the samples, sensors were used to monitor and evaluate the 2nd and 3rd harmonic parameters while ultrasonic sensors were constructed using the most suitable crystals and evaluated for their frequency and linearity with a laser vibrometer. The second part of the thesis deals with metallic materials and the application of advanced methods such as Digital Image correlation in combination with acoustic emission methods for the evaluation of mechanical properties and mapping of the damage during tensile test as well as the study of surface waves behavior during fatigue as well as the change in harmonic parameters.
Trapalis Charlampos
Dissertation title
Computational study of light harvesting materials for applications in organic photovoltaics devicesAdvisor
Papageorgiou DimitriosAdvisory committee
| Loidorikis Eleftherios | Patsalas Panagiotis | |
| DMSE | Dept. Of Physics AUTH |
Abstract
Organic photovoltaics consist of two electrodes and the active material. The active material contains organic molecules as electron donor (P3HT) and electron acceptor (PCBM). The incident light excites an electron from HOMO to LUMO which coupled with a hole create an exciton. The exciton diffuses in the active material and dissociates when it meets an acceptor. There the exciton decouples with the electron following the path along the donors to one electrode and the hole to the other. The efficiency of the process is affected by the band gap of the donor and the acceptor, to diffusion length of the excitons, the morphology of the samples and the inclusion of impurities or additive (such as silver). In order to improve the efficiency of the devices new molecules, different morphologies, different concentrations are tested. Using molecular dynamics new methodologies will be developed to investigate the morphological characteristics. This will be achieved by creating (a) parameters for molecules TH4, TH8, 3HT4, 3HT8 and (b) their interaction with silver and (c) by creating methodologies for mixing and depositing molecules on the surface of sulver. These methods will be used to investigate thre molecules: (i) the oligomer 3HT8 as a model for P3HT which is an electron donor, (ii) PCBM and (iii) three isomers of ICBA (ICBA-12, ICBA-2, ICBA-5) which are used as electron acceptors.
Tsiamis Charalampos
Dissertation title
Analysis of composite piezoelectric structures using analytical and computational methodsAdvisor
Hadjigeorgiou EvangelosAdvisory committee
| Kalpakides Vasilios | Beltsios Konstantinos | |
| DMSE | DMSE |
Abstract
The piezoelectric structures (actuators, sensors, transducers) of various geometries (beams, plates, shells) are important components of technologically advanced electromechanical systems at various scales (macro, micro & nano). The operation of these materials is based on the coupling of mechanical and electrical properties and is a modern research field. For the theoretical analysis of these materials, mathematical models for the coupled macroscopic fields (mechanical, electrical, thermal), are used in combination with analytical and computational methods. The results of the analysis are used for the accurate design of composite structures with predefined mechanical and electrical properties. With the development of the electronics and nanotechnology, these materials are also included in micro- and nano- electromechanical systems (MEMS, NEMS). It is experimentally found that in the latter systems the piezoelectric materials in consideration often exhibit pronounced size-dependent phenomena that cannot be described with classical continuum models that neglect effects arising from the presence of interacting microstructures. For the study of piezoelectric structures at the micro- and nano- scales, new mathematical models are needed on the basis of theories of gradient electro-elasticity. In the latter frame, this project aim at: a) the development of a generalized mathematical model for the coupled gradient electro-elasticity and b) the study of various static and dynamical problems of piezoelectric actuators and sensors at the micro- and nano- scales using the generalized model and analytical - computational methods.
Tsolakis Nikolaos
Dissertation title
Assemblies of nanomaterials and ionic liquids. Structural and physicochemical characterization using computational methods and NMR spectroscopy.Advisor
Karakassides MichaelAdvisory committee
| George Papavassiliou | Stefan Jurga | |
| NCSR Demokritos | Adam Mickiewicz University, Poland |
Abstract
Clean and reliable energy supply is one of the most important research fields nowadays. This is due to our needs for means of energy production and storage, that do not cause any harm to the environment and human health. These needs have led researchers, to the fabrication of hybrid electronic assemblies, like lithium batteries, supercapacitors and fuel cells. This thesis will focus onto the second category of assemblies, the supercapacitors, and especially two kinds of supercapacitors. The first kind consists of transition metal oxides and ionic liquids (ILs), while the second consists of carbon nanomaterials in the presence of ionic liquids. The research areas we are aiming to explore are the mechanisms of mass and charge transfer in these supercapacitor assemblies. The methods that will be used,include, among others, Solid State NMR and computational methods. Diffusion of ILs will be thoroughly examined, the energies of adsorption /desorption will be calculated and the total electrochemical behavior of these systems will be evaluated for energy or other applications.
Tsouli Sofia
Dissertation title
Corrosion behavior of concrete metallic reinforcement in urban and industrially polluted environments for ancient monument restoration applications - Protection with the use of corrosion inhibitorsAdvisor
Lekatou AngelikiAdvisory committee
| Matikas Theodoros | Karantzalis Alexandros | |
| DMSE | DMSE |
Abstract
Stainless steels and titanium are nowadays widely used in the framework of restoration works of ancient monuments, as they combine high resistance to corrosion with good mechanical properties. Nevertheless, rapid deterioration of concrete structures due to corrosion of steel reinforcement has become a growing problem in the last decades. The objective of this dissertation is the assessment of the employment of fly ash, (as such or in combination with other compounds) as corrosion inhibitor of AISI 316L and AISI 304L stainless steels, either directly immersed in solutions simulating concrete exposed to acid rain mimicking environment (cyclic potentiodynamic polarization) or embedded in standard concrete cubes (salt spray test). Furthermore, tensile testing will be conducted during the salt spray test. Electrochemical studies will follow the exposed to salt spraying reinforcement. Similar tests will also be conducted for titanium alloy/s.
Tzialla Ourania
Dissertation title
Porous adsorbents and separation membranes based on Ionic Liquids precursorsAdvisor
Beltsios KonstantinosAdvisory committee
| Romanos Georgios | Fokas Demosthenes | |
| N.C.S.R. "Demokritos" | Materials Science and Engineering "UOI" |
Abstract
Ionic Liquids (ILs) are a class of compounds composed exclusively of ions and are liquids at temperatures below to 100°C, whereas the most widely used ILs remain liquid even at ambient temperatures. These compounds are of special interest in recent years since they compile a combination of remarkable features, such as low melting points, negligible vapor pressure, ability to dissolve a plurality of components, high chemical and thermal stability and great chemical tunability. In this dissertation, porous adsorbents and separation membranes were developed utilizing ILs as precursors. Specifically, efforts were undertaken to develop liquid membranes using the method of post-synthesis modification of porous substrates with ILs and sol-gel method. In the sol-gel method the IL was one of the components of the synthetic procedures that also served as structure directing agent of the porous network in which it was trapped. In addition, ILs were used as precursors for developing porous carbon adsorbents and porous carbon membranes for gas separations. The developed porous carbons were studied with respect to the adsorption properties for various gases as well as to their catalytic properties for oxygen reduction/reaction, whereas the developed liquid and carbon membranes were evaluated for their separation properties.
Vangelidis Ioannis
Dissertation title
Enhancement of light - matter interaction and optimization of optoelectronic devicesAdvisor
Lidorikis ElefteriosAdvisory committee
| Dimitris Papageorgiou | Apostolos Avgeropoulos | |
| DMSE | DMSE |
Abstract
With the use of the FDTD computational method a series of nanophotonics devices based on graphene will be simulated. Graphene is a novel 2D material that has the interest of the research community due to its unique optical and electrical properties. Specifically of great interest will be the use of graphene for photodetection. Moreover, with the use of the FDTD method a number of integrated photonic devices will be simulated. This device will be based on graphene in combination with other 2D materials, such as h-BN,MoS2 and WS2.
Vlahopoulou Maria-Eleni
Dissertation title
Plasma forming processes of polydimethylsiloxane and surface modification for manufacturing microfluidic devicesAdvisor
Beltsios KonstantinosAdvisory committee
| Ioannis Panagiotopoulos | Aggeliki Tserepi | |
| University of Ioannina | NCSR ''DEMOKRITOS'' |
Abstract
Plasma forming processes of polydimethylsiloxane and surface modification for manufacturing microfluidic devices
Zygounas Athanasios
Dissertation title
Thermodynamic study of the equations of state of shape memory polymersAdvisor
Kalpakides VassiliosAdvisory committee
| Nikolaos Charalampakis | Dimitris Lagoudas | |
| AUTH | Texas A&M University |
Abstract
Thermodynamic study of the equations of state of shape memory polymers
Μemos Georgios
Dissertation title
Multiscale modeling of low temperature plasma processesAdvisor
Lidorikis ElefteriosAdvisory committee
| Tserepi Aggeliki | Gogolides Evangelos | |
| Institute of Nanoscience and Nanotechnology (INN), NCSR “Demokritos” | Institute of Nanoscience and Nanotechnology (INN), NCSR “Demokritos” |
Abstract
Plasma etching, in addition to its traditional use for pattern transfer in microelectronics, is utilized in nanotechnology for the surface modification of polymeric substrates. Specifically, the interaction of plasma with polymeric substrates induces micro- and nano-roughness on the surface of the substrates which is critical for the wetting behavior and the interaction of surfaces with cells (e.g. stem cell differentiation). Given the importance of roughness, it is critical to study the parameters that affect it and ultimately to design «recipes» delivering desired roughness. The objective of the thesis is the development of a multiscale computational framework that will link the operating parameters of the plasma reactor to the micro- and nano-roughness developing on the surface of polymeric substrates during the etching process. The framework will include models for the bulk and the sheath of the plasma as well as a model for the evolution of the morphology of the surface being etched. Particular importance will be attached to the effects of surface charging by integrating a charging module in the framework. Surface charging is critical not only for the etching rate and the developing roughness on the surface of polymeric substrates but also for the wetting properties of the surface.
| PhD student | Advisor | Dissertation title |
|---|---|---|
| Alafogianni Panagiota | Barkoula Nektaria-Marianthi | Study on dispersion, environmental response and durability of nano-composite construction materials |
| Anastasiou Athanasios | Karakassides Michael | Flow Properties of Magnetic Nano-fluids in Porous Media using Nuclear Magnetic Resonance (NMR) Methods |
| Andrea Maria | Papageorgiou Dimitrios | Research and simulation of electonic and optical properties of graphene and application in opto-electronic and plasmonic devices. |
| Asimakopoulos Georgios | Karakassides Michael | Carbon based nanoporous materials with sorbent and catalytic properties |
| Aza Eleni | Panagiotopoulos Ioannis | Strongly correlated Transition Metal Oxides: Synthesis, Structure, Magnetic, Dielectric and Dynamical properties. |
| Ballaxhia Claudi | Gergidis Leonidas | Modeling mechanical, electrical & magnetic properties of composite and multifunctional materials. |
| Baltzis Dimitrios | Paipetis Alkiviades | Durability of Composite Materials reinforced in a multiscale level |
| Bardis Konstantinos | Dassios Konstantinos | Development of Non-Destructive Technique for the Structural Health Monitoring of Materials and Structures |
| Boukis Filippos | Beltsios Konstantinos | Compact membrane reactor combined with novel membrane in intensification systems to produce low-cost hydrogen from biogas (CO COMMERCIAL) |
| Chalkia Vasiliki | Avgeropoulos Apostolos | Synthesis, Characterization and Modification by the Gel-Casting Method of Advanced Ceramic Materials |
| Chalmpes Nikolaos | Gournis Dimitrios | Development and study of novel two dimensional nanostructures for technological applications |
| Choleva Evangelia | Beltsios Konstantinos | Nanostructured adsorbents and membranes for biogas refining and upgrade via H2S capture and CO2/CH4 separation processes |
| Chroneou Evangelia | Kalpakides Vassilios | Mathematical and computational simulation for the hydrodynamics of Lake Pamvotis |
| Cutrano Carla | Lekka Christina | Computational design of functional Fe- and Cu- based coatings for environmentally sustainable applications |
| Dagkli Alkmini-Vasiliki | Lidorikis Elefterios | Enhanced light-matter interactions and optoelectronic devices based on graphene |
| Dalla Panagiota-Aikaterini | Matikas Theodoros | Study of Mechanical and Electrical Behavior of Nano-Reinforced Multifunctional Construction Materials |
| Dimitriadis Konstantinos | Agathopoulos Simeon | Desighn, synthesis and characterization of novel glasses and glass-ceramics in the system R2O-CaO-MgO-SiO2-P2O5-TR2O3 (R:Li, Na, K, TR: B2O3, Al2O3) for applications in dentistry |
| Doukas Spyridon Chrysovalantis | Lidorikis Elefterios | Study and simulation of graphene based photonic devices from NIR to FIR |
| Exarchos Dimitrios | Matikas Theodoros | Characterization of advanced materials deterioration in aged structures with non- destructive methods of thermography |
| Floros Ioannis | Hadjigeorgiou Evangelos | Development and optimization of innovative membranes and hybrid desalination systems |
| Foteinidis Georgios | Paipetis Alkiviades | Smart micro- and nano-composites: non destructive evaluation of production and /or response to various loadings |
| Georga Eleni | Fotiadis Dimitris | Development of Physiological Metabolic Models in Diabetes Based on Data Mining Techniques |
| Gioti Christina | Papayannis Dimitrios | Theoretical and experimental study of structure and properties of phosphate glasses with transition elements |
| Giousis Theodosis | Gournis Dimitrios | Design, development and study of novel 2D materials beyond graphene |
| Ioannou Koulla | Lekka Christina | Computational study of biocompatible materials |
| Ioannou Chrysoula | Matikas Theodoros | Development and study of the Life Cycle Analysis of Building Strustures in Greece |
| Kaklamanis Konstantinos | Papageorgiou Dimitrios | Computational study of charge transport in organic optoelectronic materials and devices |
| Karalis Georgios | Paipetis Alkiviades | Development of technologies for thermoelectric energy harvesting with embedded multifunctional properties from advanced composite materials |
| Karouta Niki | Gournis Dimitrios | Nanosized hybrid superstructures: Synthesis, characterization and study of properties |
| Karydis-Messinis Andreas | Zafeiropoulos Nikolaos | Development and characterization of polymer hydrogel scaffolds for biomedical applications |
| Kordatou Theodoti | Matikas Theodoros | Processing and Analysis of Digital and Analog Data for Nondestructive Characterization Development Methods of Materials and Structures |
| Kosarli Maria | Paipetis Alkiviades | Novel concepts for optimizing the self-healing processes in advanced aerospace composite structures. |
| Kotanidis Alexios | Lidorikis Elefterios | Computational study and design of nanostructured surfaces for applications in optoelectronic devices. |
| Kyriaki Tsirka | Paipetis Alkiviades | Study of the graphitic reinforcement of hierarchical epoxy matrix composites. |
| Lambrou Eleftherios | Gergidis Leonidas | Development of mathematical and computational models for the investigation of materials under mechanical, electric-magnetic or thermal fields. |
| Manesi Gkreti-Maria | Avgeropoulos Apostolos | Macromolecular Architecture: Synthesis, characterization and Properties of Linear and Non-Linear Copolymers of Polystyrene and Poly(dimethylsiloxane) for nanotechnology applications |
| Mathiou Christina | Karantzalis Alexandros | Development and characterization of novel high entropy alloy systems with two or more phases |
| Melissovas Sofoklis | Karakassides Michael | Development of innovative cementing recipes for cementing surface casing across unconsolidated sands in deep-water wells |
| Miskaki Christina | Avgeropoulos Apostolos | Macromolecular Architecture: Synthesis, characterization and properties of copolymers and terpolymers for applications in nanotechnology |
| Mourkas Angelos | Panagiotopoulos Ioannis | Study of reversal and dynamic of magnetism in nanomaterials with controllable anisotropy |
| Mourlas Athanasios | Karakassides Michael | Comparative evaluation of deposits and properties of ceramic and composite materials |
| Moutsios Ioannis | Avgeropoulos Apostolos | Synthesis and Characterization of Diblock Copolymers and Triblock Terpolymers for Nanotechnology Applications |
| Mouzourakis Eleftherios | Deligiannakis Ioannis (Interdeparmental | Production of Nanomaterials with Flame Spray Pyrolysis for Environmental & Catalytic Technologies |
| Mytafides Christos | Paipetis Alkiviades | Smart coatings for targeted functionalities in advanced structural composite materials |
| Orfanidis Savvas | Paipetis Alkiviades | Development and study of novel advanced composite material simulating the operation environment . |
| Papadopoulos Theofilos | Fotiadis Dimitris | Surveillance and modeling of Heart Failure using sensors and biosensors |
| Papanikolaou Anna | Kalpakides Vassilios | The inverse problem of elasticity in the framework of configurational mechanics |
| Patsouras Christos | Kalpakides Vassilios | The material forces in structural design optimization |
| Pezoulas Vasileios | Fotiadis Dimitris | Processing and analysis of medical and other related big data |
| Polymerou Anastasia | Paipetis Alkiviades | Advanced structural composites with architectured design for selected functionalities |
| Rapanakis Panagiotis | Kalpakides Vassilios | Computational and theoretical homogeneity in the material space |
| Roumpi Maria | Agathopoulos Simeon | Development of implants for use in experimental model of the right ventricular pressure overload |
| Smyrlis Vasileios | Fotiadis Dimitris | Modelling and computatational estimation of movement in subjects with balance disorders and investigation with sensors |
| Spanos michael | Avgeropoulos Apostolos | Conjugated Polyelectrolytes: Synthesis, Proeprties Characterization and Applications in Organic Electronic Devices |
| Stavrou Vasileios | Gergidis Leonidas | Study of magnetic materials using micromagnetic simulations |
| Subrati Yadulla Mohammed Saleem | Gournis Dimitrios | Synthesis and characterization of nanoparticles with application for the oil and gas industry |
| Tatsis Efthymios | Matikas Theodoros | Pavement Management System development in order to evaluate the pavement quality and optimize the recovery |
| Thanos Christos | Panagiotopoulos Ioannis | Fabrication and Electrical characterisation of flexible resistive switching devices (RSD) by printing technologies |
| Thomou Eleni | Gournis Dimitrios | Design and Study of Pillared Graphenes and Nanoporous Carbon Materials for Energy, Environmental and Catalytic Applications |
| Toulfatzis Anagnostis | Paipetis Alkiviades | Characterization, cutting processes and machinability of lead-free brasses |
| Tragazikis Ilias | Matikas Theodoros | Non-Destructive Characterization of Mechanical / Environmental Degradation of Nano-Composite Construction Materials using Acoustic Techniques |
| Trapalis Charlampos | Papageorgiou Dimitrios | Computational study of light harvesting materials for applications in organic photovoltaics devices |
| Tsiamis Charalampos | Hadjigeorgiou Evangelos | Analysis of composite piezoelectric structures using analytical and computational methods |
| Tsolakis Nikolaos | Karakassides Michael | Assemblies of nanomaterials and ionic liquids. Structural and physicochemical characterization using computational methods and NMR spectroscopy. |
| Tsouli Sofia | Lekatou Angeliki | Corrosion behavior of concrete metallic reinforcement in urban and industrially polluted environments for ancient monument restoration applications - Protection with the use of corrosion inhibitors |
| Tzialla Ourania | Beltsios Konstantinos | Porous adsorbents and separation membranes based on Ionic Liquids precursors |
| Vangelidis Ioannis | Lidorikis Elefterios | Enhancement of light - matter interaction and optimization of optoelectronic devices |
| Vlahopoulou Maria-Eleni | Beltsios Konstantinos | Plasma forming processes of polydimethylsiloxane and surface modification for manufacturing microfluidic devices |
| Zygounas Athanasios | Kalpakides Vassilios | Thermodynamic study of the equations of state of shape memory polymers |
| Μemos Georgios | Lidorikis Elefterios | Multiscale modeling of low temperature plasma processes |
