department of physics - Πανεπιστήμιο Πατρών · 2 • university of patras •...

PhysicsResearch Activi t ies

department of

University of Patras

U R APat

Department of Physics • UNIVERSITY OF PATRAS • 1

The Physics Department of the University of Patras was founded in 1964 and is among the oldest Departments of our University; in 2014 we will celebrate its fifty years of fruitful activities. It is located at the University of Patras campus, about 8 km north of downtown Patras. Currently it is divided in four Sections, namely:-Applied Physics-Condensed Matter Physics- Electronics and Computers, and -Theoretical & Mathematical Physics, Astronomy & Astrophysics.

The faculty of the department offer undergraduate and graduate courses not only at the department but also at other departments of the University of Patras and other Greek Universities. Research is a key activity as demonstrated by the num-ber of papers published annually in peer reviewed international scientific journals and also by the number of international research programs in which our faculty participate.

As you will realize when browsing this brochure, our faculty have built along the years close collaborations with universities, research institutes and industries in Europe, the U.S.A. and Asia. Senior faculty members of the department are internationally recognized scientists in their fields.

The purpose of this brochure is to present an overview of the curriculum and the research activities of the Department of Physics. I encourage those having a specific interest in our research, to contact the individual faculty members directly and to visit us.

You may find detailed information by in the web page of the department (www.physics.upatras.gr) and also in the web pages of our Laboratories and Research Groups.

Athanassios A. ArgiriouAssociate Professor

Head of the Department

Introduction by the Head of the Department

2 • UNIVERSITY OF PATRAS • Department of Physics

Table of contents

Department of Physics - An Introduction

Faculty Members

Solid State Physics and Polymer Physics Research Groups

Microelectronics and Composite Materials Research Group

Microelectronics Front – End Processes Research Group

Theoretical and Computational Condensed Matter Physics

Teaching Physics, History & Philosophy of Science

Liquid Crystals Research Group

Organic / Polymer and Inorganic Semiconductors Research Group – Characterization and Applications in Organic Electronics

Analog VLSI Design Research Group

Digital Information Processing Research Group

Digital Processing of Natural Signals

Embedded Systems (ES) Group

Laser Laboratory

Laboratory Of Atmospheric Physics (LAPUP)

Renewable Energy Research Group

Solar Energy Research Group

Laser, Non-Linear And Quantum Optics Research Group

Observational Astrophysics Research Group

Astroparticle Physics Research Group

Particle Physics and Cosmology Research Group

Research Profile of the Team Mechanics and Fluid Mechanics

Quantum and Classical Dynamical Systems and Quantum Information Research Group

Computational Astrophysics Research Group

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Department of PhysicsAn Introduction

The Physics Department faculty teach and carry out research on the fundamen-tal laws and phenomena of nature, starting from the structure of elementary particles up to the structure of the Universe. In addition, great emphasis is given to the practical importance of Physics since it is the pillar of modern technology. The department has an important undergraduate student body in the University with over 1600 undergraduates currently enrolled, as well as about 240 graduate students. At the moment there are 35 faculty members who undertake teaching and research activities.

The faculty of the Department are actively involved in the following topics: renewable energy sources; photoelectric properties of crystals and amorphous semiconductors; liquid crystals and their applications; optical properties of liquid crystals; magnetic materials; microelectronic materials; models of ionic devices; insulating materials and semiconductors; development of pulse gas lasers, femtosecond pulses; theoretical physics of lasers; non-linear optics; free elec-tron lasers; X-ray diffractometry; high temperature superconductors; electrical properties and photoconductivity of insulating materials and polymers; proper-ties of conductive polymers; materials, ionic mixing and embedding; lithography; atmospheric physics; design and implementation of integrated circuits; signal and image processing; dynamic astronomy; mechanical and dynamic systems; theoretical and applied astrophysics; fluid mechanics.

The above activities are supported by laboratory facilities built by the faculty of the department.

Study Programs

The Department of Physics offers the following programs:

• Undergraduate studies in Physics (Bachelors Degree, 4 years of studies)

• Graduate studies in Physics (MSc, Ph.D.)

• Interdepartmental graduate studies in Polymer Science and Technology

• Interdepartmental graduate studies in Electronics and Information Processing

Faculty of the Department of Physics also offer courses in the following graduate programs:

• Interdepartmental graduate studies in Environmental Sciences

• Interdepartmental graduate studies in Medical Physics

• Interdepartmental graduate studies in Signal and Image Processing Systems:

Theory, Implementations and Applications

• Interdepartmental graduate studies in Informatics for Life Sciences

ADMINISTRATION

Head of the DepartmentAthanassios Argiriou

Associate [email protected]

Deputy Head of the Department

Costas PsychalinosAssociate Professor

[email protected]

Contact information Department of Physics Uni-

versity of Patras265 00, Patras, Greece

Tel.: +30 2610 996072 Fax: +30 2610 996089

e-mail:

[email protected]

www.physics.upatras.gr


R E S E A R C H G R O U P S

Faculty Members

Section of Condensed Matter Physics

Stavroula Georga, ProfessorChristophoros Krontiras, ProfessorChristos Toprakcioglu, ProfessorEvangelos Vitoratos, ProfessorAikaterini Pomoni, Associate ProfessorAndreas Terzis, Associate ProfessorAlexandros Vradis, Associate ProfessorDimitrios Anastasopoulos, Assistant ProfessorLeonidas Palilis, Assistant ProfessorDimitrios Skarlatos, Assistant ProfessorNikolaos Spiliopoulos, Lecturer

Section of Electronics and Computers

Vassilios Anastasopoulos, ProfessorGeorgios Economou, ProfessorSpyridon Fotopoulos, ProfessorVassileios Giannetas, ProfessorConstantinos Psychalinos, Associate ProfessorSpyridon Vlassis, Associate ProfessorEvangelos Zygouris, Associate ProfessorDimitrios Bakalis, Assistant ProfessorMichael Fakis, Lecturer

Section of Applied Physics

Stelios Couris, ProfessorAnastasios T. Georges, ProfessorIoannis Tripanagnostopoulos, ProfessorAthanassios A. Argiriou, Associate ProfessorAndreas Kazantzidis, Assistant ProfessorGeorgios Leftheriotis, Assistant ProfessorAnastasia Rapti, Lecturer

Section of Theoretical and Mathematical Physics, Astronomy and Astrophysics

Vassileios Geroyiannis, ProfessorChristos Goudis, ProfessorSmaragda Lola, ProfessorDimitrios Sourlas, Associate ProfessorGeorgios Brodimas, Assistant ProfessorPanayiota – Eleftheria Christopoulou, Assistant ProfessorVassileios Loukopoulos, Assistant ProfessorZacharias Psyllakis, Assistant Professor


S E C T I O N O F C O N D E N S E D M A T T E R P H Y S I C S

Solid State Physics and Polymer Physics Research Groups

Research Activities

Currently, the research activities of the Solid State Physics Laboratory involve studying the structure and electronic structure of solids, surfaces, interfaces and thin films. The research interests of the Polymer Physics Laboratory focus on the structure and interaction of polymers, colloids and self-assembled systems in solution and at interfaces as well as the study of nanostructural materials.The following methods/experimental techniques are employed:

• Small-angle X-ray scattering• X-ray diffraction• X-ray reflectometry• Small-angle neutron scattering• Neutron reflectometry• Surface plasmon spectroscopy• Surface force measurements• Atomic Force Microscopy• Monte Carlo simulation

Most of the current research concerns the study of surfaces bearing polymer layers, supramolecular nanoscale structures as well as other materials such as porous media. The implementation of modified surfaces in practical applications is among the research objectives of the group.

X-ray Diffraction (XRD)X-ray diffraction is used for a quick identification of structure on a variety of samples in condensed matter physics, and in the biological and pharmaceutical sciences. Thin solid samples, thin films and powder samples can be analyzed in controlled environments (pressure, temperature).

X-ray Reflectometry (XRR)Surface modifications give rise to changes in the X-ray reflected beam at glanc-ing angles from the surface. XRR takes advantage of this effect by measuring the intensity of X-rays reflected from a surface as a function of angle. XRR can provide information on the thickness, roughness and density profile of thin films on a surface. Suitable software is used in order to analyze spectra and obtain the above information.

Surface Plasmon Spectroscopy (SPR)Surface plasmon resonance spectroscopy is widely used in the fields of physics, chemistry and biochemistry aiming to characterize surfaces and to monitor bind-ing events. With SPR spectroscopy the kinetics of macromolecular adsorption, biomolecular interactions etc, can be measured in real time. The inherent high degree of surface sensitivity allows weakly bound interactions to be monitored in the presence of excess solution species. SPR spectroscopy has been used to monitor such events as polymer adsorption, antibody-antigen binding, DNA

GROUP MEMBERS

George PriftisEmeritus [email protected]

Chris ToprakciogluProfessor

[email protected]

Alexandros VradisAssociate Professor

[email protected]

Dimitrios AnastassopoulosAssistant Professor

[email protected]

Nikolaos SpiliopoulosLecturer

[email protected]

6 graduate students

Web site:ssp.physics.upatras.gr


hybridization, and protein-DNA interactions.

Neutron Reflectometry (NR)This technique is similar in principle to XRR, the main difference being that neutrons probe nuclear contrast rather than electron density. Therefore D/H isotopic substitu-tion can conveniently be employed to generate the desired contrast when studying polymeric materials. The exact shape of the reflectivity profile provides detailed information about the structure of the surface, including the thickness, density profile and roughness of any thin film layered on the substrate. This technique is used by the group mainly for the study of adsorbed macromolecules under varying experimental conditions.

Surface Force MeasurementsThe Surface Forces Apparatus allows the direct measurement of nanometer-range forces between surfaces bearing adsorbed species such as macromolecules. The technique uses back-silvered, atomically smooth sheets of mica as substrates and employs optical interferometry to measure the distance between the surfaces with an accuracy of a few Angstroms. The interaction of adsorbed layers of polymers can thus be measured directly in a range of solvent conditions.

Electrochemical synthesis of Porous Anodic Alumina and NanowiresPorous Anodic Alumina (PAA) membranes with highly ordered hexagonal cells are fabricated by two-step anodization of aluminum in a properly designed electrochemi-cal cell. These membranes can be fabricated with different pores size and interpore distances as well as different overall thickness depending on the application they are intended for. Currently they are used as:• Templates for the growth of ordered nanowires, nanorods, nanotubes, and similar structures.• Transparent windows for radiation detectors (in collaboration with CAST experiment at CERN searching for AXIONS from sun. Spokeperson Prof. emerit. K. Zioutas)• Porous media for nanofluidics studies

Publications• Dellis, S., Christoulaki, A., Spiliopoulos, N., Anastassopoulos, D.L., Vradis, A.A. “Electrochemical synthesis of large diameter monocrystalline nickel nanowires in po-rous alumina membranes” (2013) Journal of Applied Physics, 114 (16), art. no. 164308.• Del Barrio, J., Horton, P.N., Lairez, D., Lloyd, G.O., Toprakcioglu, C., Scherman, O.A. “Photocontrol over cucurbit[8]uril complexes: Stoichiometry and supramolecular polymers” (2013) Journal of the American Chemical Society, 135 (32), pp. 11760-11763.• Anastassopoulos, D.L., Spiliopoulos, N., Vradis, A.A., Toprakcioglu, C., Menelle, A., Cousin, F. “Neutron reflectivity study of end-adsorbed bimodal polymer systems under static conditions and shear flow” (2013) Macromolecules, 46 (17), pp. 6972-6980. • Karagiovanaki, S., Koutsioubas, A., Spiliopoulos, N., Anastassopoulos, D.L., Vradis, A.A., Toprakcioglu, C., Siokou, A.E. “Adsorption of block copolymers in nanoporous alumina” (2010) Journal of Polymer Science, Part B: Polymer Physics, 48 (14), pp. 1676-1682. • Spiliopoulos, N., Koutsioubas, A.G., Anastassopoulos, D.L., Vradis, A.A., Toprakcio-glu, C., Menelle, A., Mountrichas, G., Pispas, S. “Neutron reflectivity study of free-end distribution in polymer brushes” (2009) Macromolecules, 42 (16), pp. 6209-6214.• Koutsioubas, A.G., Spiliopoulos, N., Anastassopoulos, D.L., Vradis, A.A., Toprakciog-lu, C. “Formation of polymer brushes inside cylindrical pores: A computer simulation study” (2009) Journal of Chemical Physics, 131 (4), art. no. 044901.



Microelectronics and Composite Materials Research Group

External Collaborations with:

• Institute of Advanced Materials, Physicochemical Processes, Nanotechnology& MicrosystemsNCSR “DEMOKRITOS” Athens/Greece.• Department of Material Science/University of Patras/Greece.• Surface Science Laboratory, Department of Chemical Engineering, University of Patras.• Institute of Chemical Engineering and High Temperature Chemical Processes/FORTH/Greece.• Physics Department/Aristotle University of Thessalonica /Greece. • Division of Electric Power Systems, High VoltageLaboratory, Electrical and Computer EngineeringDepartment, University of Patras. • The University of Bolton, Institute for Materials Research and Innovation, UK.• Department of Polymer Engineering, BudapestUniversity of Technology and Economics, Hungary

Scientific Activities

The research interests of the Microelectronics and Composite Materials Research Group are focused in two main areas. Specifically the group has a long standing experience on formation and electrical characterization of:• Porous and synthetic materials as well as Carbon nanotube (CNTs) and Gra-phene composites.• Study of Front – End processes for group – IV semiconductors for CMOS appli-cations: Formation and characterization of ultrathin gate dielectrics (oxides, oxyni-trides, high –k materials) on Silicon, strained Silicon and Germanium substrates.

Main Scientific Infrastructure:

The group has access to the following scientific infrastructure

• Novocontrol Dielectric Spectroscopy SystemA fully automated dielectric spectroscopy system (implementing a Novocontrol Technologies Alpha-N Dielectric Analyzer, a 4291B HP Impedance/Material Ana-lyzer and a Novocontrol Technologies Quatro Cryosystem) capable of acquiring measurements for:

• The electrical characterization of dielectrics (ε΄, ε΄΄, Μ΄, Μ΄΄, σ΄, σ΄΄, tanδ, etc) over a wide temperature (-150 up to +400oC) and frequency range (10-5Hz – 1.8GHz).• The electrical characterization of MOS structures through C-V, C-f, G-V, G-f, etc measurements.• The Keithley 585 Quasistatic CV Meter is also available at the laboratory in order to perform quasistatic CV measurements.

• Savannah – 100 Atomic Layer Deposition (ALD) System, Cambridge Nanotech USA.ALD is a surface-controlled process of depositing materials with atomic-layer accuracy. ALD proceeds through chemical reactions solely at the surface of the substrate, leading to self-limiting and layer-by-layer growth. ALD offers many

GROUP MEMBERS

C.A.Krontiras Professor

[email protected]

S.N.GeorgaProfessor

[email protected]

P. KarahaliouLecturer

[email protected]

M. PisaniasProfessor Emeritus

PhD candidates: M. Botzakaki, G. Tomara

Ms Students:A. Lazarou


advantages, including easy and accurate thickness control, excellent conformality and step coverage, high uniformity over a large area, good reproducibility, low defect density, and low growth temperatures. The Savannah – 100 ALD, at our laboratory, operates from 80oC to 300oC and the pre-cursors readily available are:

• TMA (Trimethylaluminum) and H2O as co-reactant for Al2O3 thin film growth.• Hf(NMe2)4 (TetrakisDimethylamido-Hafnium) and H2O as co-reactant for HfO2 thin film growth.• Zr(NMe2)4 (TetrakisDimethylamido-Zirconium) and H2O as co-reactant for ZrO2 thin film growth.• Any other purchased precursor substituting one of the above mentioned precur-sors with the new one.

• Microprobe stationMDC’s Cryogenic Probe Station provides a shielded, electrically quiet, atmosphere controlled environment for high sensitivity capacitance and current measurements at near liquid nitrogen temperatures from 80K up to 450K. It includes a cold chuck mounted in a sturdy aluminum light-tight dewar with a computer-controlled light, a probe stand with four (4) micropositioning probes, a microscope with both optical and video capabilities. The standard chuck size is 150 mm (6”). It is readily connected to the Novocontrol Dielectric Spectroscopy System for acquiring C-V, C-f, G-V, G-f, etc measurements at a temperature range from 80K up to 450K. It is also connected to the Transient and DC electrical conductivity measuring system. The Probing System also facilitates a wide variety of other device measurements at low temperatures such as interface trap density determination or current-voltage tests.

• Transient and DC electrical conductivity measuring system.A fully automated I-V measuring system is also available at the laboratory, based on the Keithley 2611A SourceMeter. The accuracy is in the order of 10-13A.There is also readily operational a fully automated Transient electrical conductivity measuring system able to measure I-V characteristics as a function of time from 10-6s to thousands of seconds.

Projects running:

“Heracleitus”12/138/5:“Preparation and characterization of high-k dielectric materials on top of group IV semiconductors”, (June 2011-June 2014).«Thales»356 MPN: “RESEARCH AND DEVELOPMENT OF NOVEL MULTIFUNCTIONAL POLYMER NANOCOMPOSITES”, (2012-2015).

Representative Publications

• “Dielectric relaxation phenomena and dynamics in polyoxymethylene/polyurethane / alumina hybrid nanocomposites” G. C. Psarras; S. Siengchin; P. K Karahaliou; S. N Georga; C.A Krontiras; J. Karger-Kocsis, Polym Int, 60, 1715 (2011).• “CuO/Ta2O5 core/shell nanoparticles produced by arc-discharge in water” D. De-laportas, P. Svarnas, I. Alexandrou, S.N. Georga, C.A. Krontiras, N.I. Xanthopoulos, A. Siokou, P.R. Chalker,Materials Letters, 65(15-16), 2337-2340, (2011).• “ALD deposited ZrO2 ultrathin layers on Si and Ge substrates: A multiple technique characterization”, M. Botzakaki, N. Xanthopoulos, E. Makarona, C.Tsamis, S. Kennou, S. Ladas, S.N. Georga and C.A. Krontiras, Microelectronic Engineering, 112, 208-212, (2013).• “Atomic layer deposited zirconium oxide electron injection layer for efficient organic light emitting diodes” M. Vasilopoulou, S. Kennou, S. Ladas, S. N. Georga, M. Botzaka-ki, D. Skarlatos, C. A. Krontiras, N. A. Stathopoulos, P. Argitisand L. C. Palilis,Organic Electronics 14(1), 312–319, (2013).



Microelectronics Front – End Processes Research Group

Research Activities

Study of Front – End Processes for Group – IV semiconductors (Silicon, strained-Silicon, Germanium) MOS technology:• Dopant diffusion and activation phenomena for shallow junctions formation in Silicon and Germanium: experimental study and simulations. • Study of point-extended defects and point defects – interfaces interactions in Silicon and Germanium• Growth and characterization of gate dielectrics (thermal oxides, thermal oxyni-trides, ALD deposited high-k dielectrics) for Si, strained-Si and Ge MOS technol-ogy• Silicon Non-Volatile Memories

Infrastructure

• Savannah -100 Atomic Layer Deposition System by Cambridge - Nanotech USA• Access to Novocontrol dielectric spectroscopy system (10-5 Hz – 1.8GHz)

External Collaborations

• Microelectronics Sector / Institute for Advanced Materials, Physicochemical Processes, Nanotechnology & Microsystems / NCSR “DEMOKRITOS”, Athens, Greece (Drs V.Ioannou – Sougleridis, P.Normand, P. Dimitrakis, C.Tsamis)• FONDAZIONE BRUNO KESSLER - Center for Materials and Microsystems / Micro Nano Analytical Laboratory (MiNALab), Trento, Italy (Drs M. Barozzi, M. Bersani, D. Giubertoni)• Department of Physics / Aristotle University of Thessaloniki, Thessaloniki, Greece (Prof. Ph. Komninou, Assist. Prof. N.Z. Vouroutzis)• Department of Chemical Engineering / University of Patras , Patras, Greece(Profs.S.Ladas and S. Kennou)• Materials Science Sector / Institute for Advanced Materials, Physicochemical Processes, Nanotechnology & Microsystems / NCSR “DEMOKRITOS”, Athens, Greece (Dr. Th. Speliotis)• Applied Materials / Variant Semiconductor Equipment, USA (Drs. Ch. Thomidis and B. Colombeau)

Projects Running

1.GSRT-HERAKLEITOS II, Project MIS: 346791 “Charge trapping devices (memo-ries) based on novel high-k dielectrics” [1/4/2011-31/10/2014].2.University of Patras Karatheodory-2009, Project C906 “Front-End Processes for Germanium MOS applications” [1/2/2010-30/9/2013].

GROUP MEMBERS

D. SkarlatosAssistant Professor

[email protected]

PhD candidate: N. Nikolaou

Undergraduate Students: M. Barlas, A. Karageorgiou

Savannah -100 Atomic Layer Deposition System by Cambridge - Nano-tech USA

Gallium diffusion (2010) and Nitrogen anomalous diffusion (2012) in Ge


Representative Recent Publications

1) “Gallium Implantation and Diffusion in Crystalline Germanium”N. Ioannou, D. Skarlatos, N. Z. Vouroutzis, S. N. Georga, C. A. Krontiras and C. TsamisElectrochemicalAndSolid-State Letters,13(3), P. H70-H72, (2010).2) “Influence of thermal oxidation on the interfacial properties of ultrathin Strained Silicon layers” V.Ioannou-Sougleridis, N.Kelaidis, D.Skarlatos, C.Tsamis, S.N.Georga, C.A.Krontiras, Ph.Komninou, Th.Speliotis, P.Dimitrakis, B. Kellerman and M. Seacrist Thin Solid Films, 519, p. 5456–5463, (2011).3) “Interfacial properties of ALD-deposited Al2O3 / p-type Germanium MOS struc-tures: influence of oxidized Ge interfacial layer dependent on Al2O3 thickness” M.Botzakaki, A.Kerasidou, L.Sygellou, V.Ioannou-Sougleridis, N.Xanthopoulos, S.Kennou, S. Ladas, N.Z.Vouroutzis, Th.Speliotis and D.SkarlatosECS Solid State Letters,1(2), p.32-34, (2012).4) “Nitrogen implantation and diffusion in crystalline Germanium: implantation energy, temperature and Ge surface protection dependence” D.Skarlatos, M.Bersani, M.Barozzi, D.Giubertoni, N.Z.Vouroutzis, V.Ioannou-Sougleridis ECS JournalOf Solid State Science And Technology,1(6), P.315-319, (2012).5) “The effect of oxygen source in atomic layer deposited Al2O3 as blocking oxide in MANOS memory capacitors” N.Nikolaou, V. Ioannou-Sougleridis, P. Dimitrakis, P.Normand, D. Skarlatos, K. Giannakopoulos, K. Kukli, J. Niinistö, M. Ritala, M. Leskelä, Thin Solid Films, 533, p.5-8, (2013).

Dependence of forming gas action on the dielectric thickness of Al/Al2O3/p-Ge MOS structures. Effect on border traps. Suppression of border traps increases as the dielectric thickness de-creases accompanied by lesser negative charge injection within the dielectric volume (2013).

An Al2O3 / Si3N4 / SiO2 gate stack grown on Si substrate. Performance of the cor-responding memory capacitors as a function of Al2O3 ALD deposition chemistry (2013).

10 nm Al2O3 deposited by ALD at 3000C on p-type Ge. Detection of GeOx interfacial layer by XPS. Dependence of interfacial GeOx thickness on deposited at 3000C Al2O3 thickness and influence on Al2O3 /p-type Ge interface traps density (2012).



Theoretical and Computational Condensed Matter Physics

Research Activity

Research Field(s): 1. Nanosciences, nanotechnologies, materials & new production technologies2. Information & communication technologiesKeywords: Condense matter physics. Low dimensional theoretical and computational solid state physics. Complex fluids computational physics.Theoretical polymer phys-ics.

Research activityTheoretical and computational studies in: Condense matter physics. Liquid crys-tals and mesophases. Polymer physics of dendrimers, brushes, star polymers and polymeric solutions. Static and dynamic properties of low dimensional quan-tum systems (quantum dots, wires and wells). Coherent control in semiconductor nanostructures with optoelectronic applications. Coherent control in semiconduc-tor nanostrutures with applications in quantum computation (creation of entan-gled states and quantum gates).

Facilities: Computers cluster.

Research Activities

Selected research projects: Research Project Arhimedes III. «Quantum coherence and interference in non-linear optical processes in semiconductor nanostructures». (University of Patras, 2012-present). Research team member.Selected publications: • D.D. Smith, M. Dutta, X.C. Liu, A.F. Terzis, A. Petrou, M.W. Cole, and P.G. New-man, `Magnetoexciton spectrum of GaAs-AlAs quantum wells’, Phys. Rev. B 40, 1409 (1989).• A.F. Terzis and D. J. Photinos, `Electrostatic interactions in liquid crystals: order-ing of rigid solutes in nematic solvent’, Mol. Phys. 83, 847 (1994).• R.H. Terrill, A. Postlethwaite, C.D. Poon, A. Terzis et al., `Monolayers in Three Dimensions: NMR, SAXS, Thermal, and Electron Hopping Studies of Alkanethiol Stabilized Gold Clusters’, J. Am. Chem. Soc. 117, 12537 (1995).• A.F. Terzis, D. J. Photinos and E.T. Samulski, `Quantitative Calculation of Spon-taneous Polarization in Ferroelectric Liquid Crystals’, J. Chem. Phys. 107, 4061 (1997).• S. Baskoutas, E. Paspalakis and A. F. Terzis, ‘Effects of excitons in nonlinear op-tical rectification in semi-parabolic Quantum Dot’, Physical Review B, 74, 153306 (2006).• A.F. Terzis, D.. Theodorou and A. Stroeks, `Entanglement Network of the Poly-

GROUP MEMBERS

Andreas F. Terzis,Associate Professor

Ph.D studentsEvangelos Voutsinas

Subject:“Quantum control of the

dynamics of semiconductor quantum dots”.

Kostas BlekosSubject:

“Theoretical and computa-tional study of nanostruc-tures with applications in

quantum computing”.

Petros Androvitsaneas Subject:

“Quantum Monte Carlo investigation of prototype

quantum systems with applications in quantum

computing”.

Master studentsNikos Iliopoulos

Maria-Eftaksia Stasinou


propylene/Polyamide Interface. 3. Deformation to fracture’, Macromolecules 35, 508 (2002).• A.F. Terzis, `Bidisperse Melt Polymer Brush studied by Self-Consistent Field Model’, Polymer 43, 2435 (2002).• E. Paspalakis, Z. Kis, E. Voutsinas and A. F. Terzis, `Controlled rotation in α double quantum dot structure’, Phys. Rev. B 69, 155316 (2004).• S. Baskoutas and A. F. Terzis, `Size-dependent band gap of colloidal quantum dots’, J. Appl. Phys. 99, 013708 (2006).• S. Baskoutas, E. Paspalakis and A. F. Terzis, ‘Electronic structure and nonlinear optical rectification in a quantum dot: Effects of impurities and external electric field’, J. Phys.: Cond. Matt. 19, 395024 (2007).• Petros Androvitsaneas, Andreas F. Terzis, and Emmanuel Paspalakis, ‘Localizable entanglement in antiferromagnetic and mixed Heisenberg chain quantum: a quan-tum Monte Carlo study’, Quantum Information Processing, 12, 831(2013).• A.F. Terzis, ‘A simple relativistic Bohr atom’, Eur. J. Phys.29, 735 (2008).

Cooperations with other Organizations and Institutes:

1. Imperial College London, Physics Department (UK).2. University of North Carolina, Chemistry Department (USA).3. Physics and Chemistry Departments, University of Cyprus.4. Physics and Chemistry Departments, University of Ioannina, Greece5. Foundation for Reasearch and Technology - Hellas6. Department of Chemical Engineering, University of Patras, and Institute of Chemi-cal Engineering Sciences.7. Department of Chemical Engineering,National Technical University of Athens, Greece



Teaching Physics, History & Philosophy of Science

Research Activities – Research Fields

Conceptual Physics Teaching. Physics Education.History and Philosophy of Physics.

Collaborations (with other Research Groups/Institutes in Greece or abroad)

Department of Educational Sciences and Early Childhood Education, U. Patras; Department of Philosophy U. Patras; School of Early Childhood Education, Ar-istotle University of Thessaloniki; Faculty of Physics, Al. I. Cuza University, Iasi, Romania;

Recent or Representative Publications

1. “Incorporating Poeticality into the Teaching of Physics”, Panagiotis Pantidos, Konstantinos Ravanis, Kostas Valakas, Evangelos Vitoratos. Sciece & Education, DOI 10.1007/s11191-012-9573-2, Published online: 05 Jan.20132. “Physics Teacher Education & its European Dimension” by E. Vitoratos, O. Caltun, R-M Speradeo-Mineo, in TEACHING PHYSICS IN EUROPE, (Brochure of STEPS TWO Project). ISBN:978-973-558-595-2. Eds.: L. Tugulea, G. Jones, J. Naudts. Bucuresti, (2011).3. “Some Reflections on the Origin, Meaning and Importance of the first Rational Explanation of the World given by the Milesian Philosophers” by S. Sakkopoulos E. Vitoratos. 7th Gen. Conf. of the Balkan Phys. Union (BPU).Alexandroupolis, Greece, (2009).4. “Atomism: A Fundamental Concept in Ancient Philosophical Theories of two Different Cultures, Indian and Greek”. European Physical Society Conference. Athens 2005) publishedin the book: “Notions of Physics in Natural Philosophy”, Cambridge Scholars Publishing. Edited by G. Vlahakis.ISBN(10): 1-84718-430-8, pages: 97-109 (2008).5. “Empirical Foundations of Atomism in Ancient Greek Philosophy” by S. Sak-kopoulos and E. Vitoratos. Science & Education, 5(3), 293-303, (1996).6.”Reference Points for the Design & Delivery of Degree Programmes in Physics” by L.F. Donà dalle Rose, E. Cunningham, M.C. do Carmo, F. Cornet, M. Ebel, H. Ferdinande, H. Geurts, W.G. Jones, E. Kierlik, F. Matteucci, J. Niskanen, G. Ny-man, P. Sauer, S. Steenstrup, O. Suk, L. Tugulea and E.G. Vitoratos, (Brochure of the Physics Subject Area Group), Tuning Educational Structures in Europe. ISBN: 978-84-9830-168-7, Bilbao, Spain, (2008).7. “Count Rumford, a Social Benefactor through Physics” by S. Sakkopoulos, E. Vitoratos.11thInternational IHPST and 6th Greek History, Philosophy and Science Teaching Joint Conference.Thessaloniki, Greece, (2011).8. The Materiality of Narrative Spaces: A Theatre Semiotics Perspective into the Teaching of Physics. Pantidos P, Valakas K, Vitoratos E, Ravanis K. Semioticα, 182(1-4), 2010, Pages 305–325. DOI: 10.1515/semi.2010.062

GROUP MEMBERS

Academic Staff:

E. VitoratosProfessor

[email protected]

S. SakkopoulosRetired Professor

[email protected]


Recent Projects

1. EUPEN - European Physics Education Network – (SOCRATES 1995-2003, Univ. of Gent Belgium). Participation in the period 2001-2003.

2. TUNING - Tuning Educational Structures in Europe – (SOCRATES 2000-2008, Co-ordinators: Unin. of Deusto in Bilbao, Spain & Univ. of Groningen, Netherlands). Prof Vitoratos was a member of the Subject Area Group (SAG) in Physics. http://www.unideusto.org/tuningeu/

3. STEPS - Stakeholders Tune European Physics Studies – (SOCRATES – ERASMUS Thematic Network 2005-2008, Univ. of Gent Belgium; 153 participating Institutions). Member of the Working Group (WG) 2: “Relations of research and education, excel-lence; importance of Physics”. Member of the Executive Group. http://www.eupen.ugent.be/

4. STEPS TWO - Stakeholders Tune European Physics Studies - (142371-LLP-1-2008-1-BE-ERASMUS-ENW) Lifelong Learning, 2008-2011, Univ. of Antwerp & Univ. of Bucharest). Prof. E.G. Vitoratos was a member of the Management Committee.STEPS-TWO had Three Lines of Action Developing Policy recommendations and of-fering Solutions for Concrete Strategies: * Curricula after Bologna & Life-Long-Learn-ing (Chair: U. Titulaer, Johannes Kepler University Linz, Austria). * Modern Teach-ing Methods and Student-centered Learning (Chair: S. Feiner-Valkier, Eindhoven University, Netherlands). *Physics Teacher Education (Chair: E. Vitoratos, University of Patras, Greece). Info: http://143.169.5.54/main2/ andhttp://www.stepstwo.ua.ac.be/ ~ stepstwo / FinalReport.pdf

5.HOPE - Horizons in Physics education – (REF:540130-LLP-1-2013-1-FR-ERASMUS-ENW, Lifelong Learning, 2013-2016, Coordinators: Univ. P & M Curie, Paris, Univ. of Strathclyde & Univ. of Udine; 71 participating Institutions). Prof Vitoratos is a member of the Advisory Board. HOPE has four lines of action:

1. Inspiring young people to study Physics2. New Competences for Physics Graduates – Fostering Innovation & Entrepre-neurship3. Improvements in Physics Teaching – Meeting Future Global Challenges in Physics Higher Education4. Improvements in the Training & Supply of PhysicsSchool Teachers.



Liquid Crystals Research Group


• Electrooptical and physicochemical characterization of liquid crystalline materials.• Static distrortions and electrohydrodynamic instabilities in liquid crystals.• Light propagation in inhomogeneous anisotropic media.• Liquid crystals for device applications: symmetries, alignment, molecular or-ganization, electrooptic response, phase transitions.• Molecular self-assembly and self-organisation of liquid crystalline materials. • Investigation of structure – properties relationships of liquid crystalline materials.

Main Scientific Infrastructure

• Zeiss Axioskop 40 pol Transmitted light model (objective lenses: 5x, 10x, 20x, 50x, transmitted light illuminator: 12V, 35W, rotary stage, camera: ProgRes CT5 with software CapturePro 2.7 for microscope image analysis and documentation)• LTS420 Heating and Freezing stage system της Linkam with LNP95 liquid ni-trogen cooling pump system (Temperature range: -196 °C to 420 °C, Max heating rate 40 °C / min)• Experimental setup for the electrooptic response and measurement of the instabilities relaxation time: 1. DC power Supply Hewlett Packard 6684-A (0-40 V DC, 0-128 A, 5000W), TGA1241 40 MHz arbitrary function generator2. 79300 He-Ne laser (Oriel)3. Photodiode detector (model 71581 Oriel)4. Amplifier (model 70710 Oriel)5. DI-720P data acquisition system (DATAQ Instruments), 16-bit resolution and up to 250kHz waveform recording capability with WINDAQ software

Representative Publications E. Ramou, H.M. Zenginoglou and P.L. Papadopoulos, “On an objective experimen-tal method for the determination of the electrohydrodynamic instability thresholds in a nematic liquid crystal”, Liquid Crystals, 2013, http://dx.doi.org/10.1080/02678292.2013.828329.P. K. Karahaliou, A. G. Vanakaras and D. J. Photinos, “Symmetries and alignment of biaxial nematic liquid crystals”, JCP, 131, 124516 (2009).S. D. Peroukidis, P. K. Karahaliou, A.G. Vanakaras and D. J. Photinos, “Biaxial nematics: symmetries, order domains and field-induced phase transitions”, Liq. Cryst., 36, 727 (2009).P. K. Karahaliou, P. H. J. Kouwer, T. Meyer, G. H. Mehl and D. J. Photinos, “Long and short – range order in the mesophases of laterally substituted calamitic me-sogens and their radial octapodes”, J. Phys. Chem. B, 112, 6550 (2008).P. K. Karahaliou, P. H. J. Kouwer, T. Meyer, G. H. Mehl and D. J. Photinos,“Columnar phase structures of an organic-inorganic hybrid functional-ized with eight calamitic mesogens”, Soft Matter, 3, 857 (2007).S. Diez, D.A. Dunmur, M. R. De La Fuente, P. K. Karahaliou, G. Mehl, T. Meyer, M. Α. Peréz Jubindo and D. J. Photinos, “Dielectric studies of a laterally-linked silox-ane ester dimer”, Liq. Cryst., 30 (9), 1021 (2003).ONE PAGE ONLY

GROUP MEMBERS

H. Zenginoglou Associate Professor

[email protected]. Karahaliou

[email protected]

PhD candidatesE. Ramou

[email protected]


Organic / Polymer and Inorganic Semiconduc-tors Research Group – Characterization and Applications in Organic Electronics


Research Activities – Research Fields

Inorganic semiconductors - Optoelectronic and Transport properties (DC and tran-sient photoconductivity, DC conductivity, Hall Effect) - Electrical Conductivity/Photo-conductivity Models

Organic semiconductors (Small organic molecules, Conjugated Polymers) - Optoelec-tronic, Transport and Structural properties (DC conductivity, Photoconductivity, Crys-tallinity, Morphology,Photophysics). Photo and Thermal Degradation/Aging Studies - Mechanisms and Correlations to Materials Structure - Electrical Conductivity Models

Applications in Organic Photonics and Electronics such as Organic Light Emitting Diodes (OLEDs) and Photovoltaic Cells (OPVs)

Other materials such as Inorganic Molecular and Transition Metal Oxides – Properties and Applications as Interfacial Layers in Organic Electronic Devices

Infrastructure - Facilities

Spin coating apparatus for thin film deposition. Controlled temperature heating stage for annealing processes. Thermal evaporator for metal deposition. Equipment for optical and electrical characterization at various temperatures.

Collaborations (with other Research Groups/Institutes in Greece or abroad)

Department of Electrical Engineering, Technological Educational Institute of Patras, Greece; Department of Medical Instruments Technology, Technological Educational Institute of Athens, Greece; Institute of Advanced Materials, Physicochemical Pro-cesses, Nanotechnology and Microsystems (IAMPPNM), National Center for Scientific Research “Demokritos”, Aghia Paraskevi, Greece; Faculty of Applied Physics and Mathematics, Technical University of Gdansk, Gdansk, Poland; Faculty of Physics, Al. I. Cuza University, Iasi, Romania; Departments of Physics/Chemical Engineering/Chemistry/Materials Science/Electrical Engineering, University of Patras, Greece; Department of Physics, University of Athens, Greece; Department of Electronic Engi-neering, Technological-Educational Institute of Piraeus, Aigaleo, Greece; Department of Mechanical Engineering and Materials Science and Engineeting, Cyprus University of Technology, Limassol, Cyprus; CNRS and Universite de Bordeaux, France; US Naval Research Laboratory, Washington DC, USA, USA; Fraunhofer Institute of Solar Energy, Freiburg, Germany; Imperial College, London, UK; University of Sheffield, Sheffield, UK.


1. “Exploring electrical conductivity within mesoscopic phasesof semiconducting

GROUP MEMBERS

S. SakkopoulosRetired Professor [email protected]. [email protected]. PomoniAssoc. Professor [email protected]. PalilisAssist. Professor [email protected]

PhD students: D. KarageorgopoulosD. SygkridouA. ApostolopoulouT. Georgakopoulos

MSc students: A. Koutsoubelitis


poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate)films by broadband dielectric spectroscopy”, A. N.Papathanassiou, I.Sakellis,J.Grammatikakis,E.Vitoratos,S.Sakkopoulos, App. Phys. Lett.103, 123304, 2013.2. “Thin ZnO nanocrystalline films for efficient quasi-solid stateelectrolyte quan-tumdot sensitized solar cells”, D.Karageorgopoulos, E.Stathatos, E.Vitoratos,J. of Power Sources 219, 9-15, 2012.3. “Thermal degradation mechanisms of PEDOT:PSS”, E.Vitoratos, S.Sakkopoulos, E.Dalas, N.Paliatsas, D.Karageorgopoulos, F.Petraki,S.Kennou, S.A.Choulis, Org.Electr.10, 61-66, 2009.4. “Dark conductivity and transient photoconductivity ofnanocrystalline undoped and N-doped TiO2 sol–gel thin films”, K.Pomoni, A.Vomvas, C.Trapalis, Th. Sol. Fil.516(6), 1271-1278, 2008.5. “Electrical conductivity studies of anatase TiO2 with dominant highly reactive {001} facets”, K.Pomoni, M.V.Sofianou, T.Georgakopoulos, N.Boukos, C.Trapalis,J. Alloys and Compd. 548, 194-200, 2013.6. “Thermal treatment and environment effect on transient photoconductivity be-havior of anatase TiO2 with dominant {001} facets”, K.Pomoni, T.Georgakopoulos, M.V.Sofianou, C.Trapalis,J. Alloys and Compd. 558, 1-5, 2013.7. “The influence of hydrogenation and oxygen vacancies in molybdenum ox-ides work function and gap states for application in organic optoelectronics”, M.Vasilopoulou, A.M.Douvas,D.G.Georgiadou, L.C.Palilis, S.Kennou, L.Sygellou, A.Soultati, I.Kostis, G.Papadimitropoulos, D.Davazoglou, P.Argitis,J. of the Amer. Chem. Soc., Vol. 134, p. 16178-16187, 2012.8. “Solution processable tungsten polyoxometalate as highly effective cathode interlayer for improved efficiency and stability polymer solar cells”, L.C.Palilis, M.Vasilopoulou, A.M.Douvas, D.G.Georgiadou, S.Kennou, N.A.Stathopoulos, V.Constantoudis, P.Argitis, Solar Energy Materials and Solar Cells, Vol. 114, p. 205-213, 2013.9. “Atomic layer deposited ultra thin zirconium oxide electron injection layer for efficient organic light emitting diodes”, M.Vasilopoulou, S.Kennou, S.Ladas, S.N.Georga, M.Botzakaki, D.Skarlatos, C.A.Krontiras, N.A.Stathopoulos, P.Argitis,L.C.Palilis, Org. Electr., Vol. 14, p. 312-319, 2013.

Recent Projects

1. “Novel low power consumption Hybrid OLEDs with improved operational char-acteristics” (NHyOLED) within the framework of Research Grants ARCHIMEDES - III, Funding: Ministry of Education, Lifelong Learning and Religious Affairs, Greece (2012-2014).2. “Novel and highly efficient Hybrid organic photovoltaic cells” (NHyOPV) within the framework of Research Grants ARCHIMEDES - III, Funding: Ministry of Educa-tion, Lifelong Learning and Religious Affairs, Greece (2012-2014).3. “Polymeric photonic systems for application in information technologies” (PHO-TOPOLIS) within the framework of Research Grants THALES, Funding: Ministry of Education, Lifelong Learning and Religious Affairs, Greece (2012-2015).4. “Plasma directed assemply of nanostructures and applications” (PlasmaNano-Factory) within the framework of Research Grants ARISTEIA, Funding: Ministry of Education, Lifelong Learning and Religious Affairs, Greece (2012-2015).5. “Implementing advanced interfacial engineering strategies for highly efficient hybrid solar cells” (IMAGINE-HYSOL) within the framework of Research Grants ARISTEIA II, Funding: Ministry of Education, Lifelong Learning and Religious Af-fairs, Greece (2014-2016), Budget: 300,000 Eyros. Principal Investigator: Assist. Prof. L. Palilis, Department of Physics, University of Patras, Greece.

Low temperature conductivity and photoconductivity measurements apparatus

Transient photoconductivity of sol-gel TiO2 thin films in air for different light intensities

S E C T I O N O F E L E C T R O N I C S A N D C O M P U T E R S

Analog VLSI Design Research Group


Research Activities

The main research subject of Analog VLSI Design Team is the design of analog integrated circuits for signal processing. The team is involved with the development of analog circuits for biomedical and short-range wireless applications,ultra-low volt-age circuit/systems, and high speed transceivers for optical communication. Our research activities could be summarized in the following:• Design of analog circuits for biomedical applications

Building blocks for processing EEG signals.Building blocks for processing ECG signals.Building blocks for neural models.

• Design of ultra-low voltage analog integrated circuits:Building blocks (opamps, transconductors, multipliers) for ultra-low voltage power supply.Bulk-driven circuits/systems.

• Design of continuous and discrete time analog filters. Companding filters (Log-Domain and Sinh-Domain filters).Continuous time linear filters with current-mirrors, CFOAs, CCIIs, etc.Discrete time (switched-capacitor, switched-current) linear filters.

• High speed transceivers for optical communicationsHigh speed interfaces for optical communications PLL architecture for high speed interface

Infrastructure – Facilities

Cadence IC design software. Cadence Orcad v16 software. A working position equipped with HP4395 Network/Spectrum Analyzer, two Agilent 33250A arbitrary waveform generators and an Agilent DSO 6034A 4-channel oscillo-scope for the experimental verification of ICs. Five working positions, equipped with Agilent DSO 3000 oscilloscopes and Agilent 33220A arbitrary waveform generators where measurements can be performed through Internet (remote lab).

Collaborations

Brno University of Technology, Department of Microelectronics, Brno, Czech Republic.University of Kashmir, Department of Electronics and Instrumentation Technology, Srinagar, India.

Representative Publications

C. Laoudias, C. Psychalinos, “Integrated filters for short range wireless and biomedi-

GROUP MEMBERS

C. PsychalinosAssociate [email protected]. VlassisAssociate [email protected]. [email protected]. KafePhD [email protected]. TsirimokouPhD [email protected]. C. DemartinosPhD [email protected]. TsimposPh.D. [email protected]

M.Sc. students from Post-graduate Curriculum on “Electronics & Communica-tions”


cal applications”, Springer 2011, ISBN: 978-1-4614-0259-6.C. Laoudias, C. Psychalinos, “1.5 V complex filters using current mirrors”, IEEE Transactions Circuits and Systems-II, vol. 58, no.9, pp. 575-579, Sept. 2011.C. Kasimis, C. Psychalinos, “Design of Sinh-Domain Filters Using Complementary Operators”, International Journal of Circuit Theory and Applications,vol. 40, no. 10, pp. 1019–1039, Oct. 2012.G. Tsirimokou, C. Laoudias, and C. Psychalinos, “Tinnitus Detector Realization Us-ing Sinh-Domain Circuits”, Journal of Low Power ElectronicsVol. 9, 1–13, 2013. F. Kafe, C. Psychalinos, “Realization of companding filters with large time-constants for biomedical applications”, to be published in Analog Integrated Circuits and Signal Processing.F. Khateb, S. Vlassis, “Low-voltage bulk-driven rectifier for biomedical applica-tions”, Microelectronics Journal, vol. 44, no.8, pp. 642–648 Aug. 2013.G. Raikos, S. Vlassis, “0.8 V Bulk-Driven Operational Amplifier”, Analog Integrated Circuits and Signal Processing, vol. 63, no. 3, pp. 425-432, June 2010

Recent Projects

“Design of low-voltage Sinh-Domain analog integrated filters”, funded by the GSRT within the framework of “Heraclitus-II”.“Development of low-voltage companding filters and their implementation in IC form”, in collaboration with the Department of Electronics and Instrumenta-tion Technology, University of Kashmir, Srinagar India, funded by the University Grants Commission (UGC), India.Innovated sensors systems development with distributed intelligence MEMsense. ( Financing by Corallia, National resource, European Regional Development Fund 2007-2013, project no. 84009, MICRO-49/ Ε-ΙΙ-Α)Next generation millimeter wave radio-link , -NextGenMiliWave ( Financing by Corallia, National resource, European Regional Development Fund 2007-2013, project no.84702 MICRO-49/ Ε-ΙΙ-A)

Contact details

University of Patras, Physics Dept., Electronics Lab., GR-26504 Rio Patras, Greecewww.ellab.physics.upatras.gr, e-mail: [email protected], [email protected]

Current-mode analog filter for Bluetooth/Zig-bee systems (tech: AMS 0.35um)


Digital Information Processing Research Group


Research Activities

Among the active research groups that comprise ELLAB, the Digital Information Processing Research Group is composed of more than 20 people, including Academic Staff, PostDoc, Ph.D. and M.Sc. students, and is currently certified as one of the most active R&D Groups in the Information Processing society of Greece. The main R&D activities are mostly related with image & multimedia information processing, pattern recognition & machine learning methodologies, as well as earth observation & remote sensing techniques. In their latest publications, researchers are involved in the fields of:1. Computer vision, Pattern Recognition & Applications. Includes feature extraction and selection methods, neural nets, vector quantization, classification and clustering techniques, dimensionality reduction, data and image fusion, pattern identification and matching, etc. Application areas include: Action recognition (using RGB-D cameras), Visual saliency, Medi-cal image processing, Complex networks in brain dynamics and Meteorology.2. Biometrics: A great deal of research work is devoted to signature, face, fingerprint, gait (based on RGB-D cameras) and human centric measurements (based on eye movements and eye tracking systems).3. Multimedia Databases & Data-mining / Digital Libraries such as 2D/3D feature extrac-tion, content-based indexing and retrieval of images and video, database organization and visualization, semantic knowledge discovery and mapping, multimedia search engines, advanced descriptors and similarity metrics for images and video, etc.4. Image & Video Processing such as clustering, segmentation, color, texture and multi-spectral processing, video analysis and event recognition, video summarization, etc.).

Research Infrastructure

• High speed camera• 3D Scanner • Eye tracking system Eye-tracker (Cambridge Research Systems, Video Eyetracker Toolbox basic) with PCI frame grabber• Pen writers, fingerprints and iris readers (and relevant software)• Emotiv (Epoc) Software Development Kit for research with 14 channel EEG recorder • Pan-tilt-zoom camera for video recording

Recent R&D Projects

1. 01/01/2010 - 31/12/2013: “Herakleitos 2010: Image and Video Analysis with modern techniques of manifold Learning”, funded by the European Social Fund (ESF), Operational Program for Educational and Vocational Training II (EPEAEK II). 2. 01/06/2010 - 30/09/2010: “VIDEO-HSW - Hardware and Software architectures for pro-cessing, recognition and transmission of image and videos”, research seminars funded by three companies in the Microelectronics Cluster Initiative (Corallia), IRIDA Labs, e-Conais and DIAPLOUS ltd.3. 1/1/2012 - 31/12/2013: “BIOMETRIA - Intra-university network”, a scientific network study-ing human biometrics, funded by the the Research Committee, University of Patras. 4. 02/01/2011 - 31/12/2014: “POSTDOCTORAL Program - Understanding of Human Actions in Groups, funded by the Greek Ministry of Education.5. 2010-2013: HERAKLEITUS II, “Human Centred Processing and Analysis of Optical Information”.

GROUP MEMBERS

Economou George ProfessorElectronics [email protected]://www.upcv.upatras.gr/personal/economou/http://scholar.google.com/citations?user=j9XzkygAAAAJ&hl=enFotopoulos SpirosElectronics [email protected]@upatras.grhttp://www.upcv.upatras.gr/personal/fotopoulos/index.htmlhttp://scholar.google.gr/citations?user=L13psW4AAAAJ&hl=en&oi=ao

Ph.D studentsTheodorakopoulos Elias [email protected] [email protected] Konstantina [email protected] Rigas Ioannis [email protected] Vasileios [email protected] KonstantinosDimitriadis Stavros

PostdocsMakedonas Andreas [email protected] Dimitrios [email protected] Irene [email protected]


Cooperations

1. University of Thessaloniki, Neuroinformatics group (Dr N. Laskaris)2. The Signal Processing & Communications (SPC) Lab / Computer Engineering & Informatics Department (CEID), University of Patras (Dr C. Berberidis)3. Wire Communications Laboratory / Electrical and Computer Engineering Depart-ment , University of Patras (Dr. E. Dermatas)4. Dept of Electronics, Technological and Educational Institute of Athens/ Research and Development Telecommunications Laboratory (Dr. E. Zois)

Recent Publications

Computer vision, Pattern Recognition & Applications• Ilias Theodorakopoulos, Dimitris Kastaniotis, George Economou, Spiros Fotopoulos, “Pose-based Human Action Recognition via Sparse Representation in Dissimilarity Space” Journal of Visual Communication and Image Representation, 2013• Ilias Theodorakopoulos, George Economou and Spiros Fotopoulos “Collaborative Sparse Representation in Dissimilarity Space ”, 9th International Symposium on Visual Computing ISVC 2013, Rethymno, GreeceMedical imaging• “I. Theodorakopoulos, D. Kastaniotis , G. Economou and S. Fotopoulos, “HEp-2 cells classification via sparse representation of textural features fused into dissimilarity space, accepted in Pattern Recognition, Available online 1 October 2013 • Ilias Theodorakopoulos, Dimitris Kastaniotis, George Economou and Spiros Foto-poulos HEp-2 Cells Classification via Fusion of Morphological and Textural Features Proceedings of the 2012 IEEE 12th International Conference on Bioinformatics& Bioengi-neering (BIBE), Larnaca, Cyprus, 11-13 November 2012Brain dynamics• Stavros I. Dimitriadis, Nikolaos A. Laskaris , Vasso Tsirka, Sofia Erimaki,Michael Vourkas, Sifis Micheloyannis, Spiros Fotopoulos, ‘A novel symbolization scheme for multichannel recordings with emphasis on phase information and its application to differentiating EEG activity from different mental tasks’, Cognitive Neurodynamics vol.6 no.1 (2012) p.107-113• Dimitriadis, S.I., Laskaris, N.A., Tzelepi, A., Economou, G., “Analyzing functional brain connectivity by means of commute times: A new approach and its application to track event-related dynamics”, IEEE Transactions on Biomedical Engineering 59 (5), pp. 1302-1309, 2012Meteorology• Athanassios Zagouras, Athanassios A. Argiriou, George Economou, Spiros Foto-poulos, Helena A. Flocas “Weather maps classification over Greek domain based on isobaric line patterns” Theoretical and Applied Climatology, March 2013• P. Tzoumanikas, A. Kazantzidis, A.F. Bais, S. Fotopoulos, G. Economou, “Cloud detec-tion and classification with the use of whole-sky ground-based images” Advances in Meteorology, Climatology and Atmospheric Physics, Springer Atmospheric Sciences, 2013, pp 349-354 Biometrics• K Barkoula, E Zois, E Zervas, G Economou, “Event Based Offline Signature Modeling Using Grid Source Probabilistic Coding”, New Trends in Image Analysis and Process-ing–ICIAP 2013, pp. 77-85• Pothos, V.K., Theoharatos, C., Economou, G., “A local spectral distribution approach to face recognition”, Computer Vision and Image Understanding 116 (6) , pp. 663-675, 2012Multimedia Databases & Data-mining• Fotopoulou, F., Laskaris, N., Economou, G., Fotopoulos, S., “Advanced leaf image retrieval via Multidimensional Embedding Sequence Similarity (MESS) method”, Pattern Analysis and Applications 16 (3) , pp. 381-392, 2013• D. Besiris, A. Makedonas, G. Economou and S. Fotopoulos “Combining Graph Con-nectivity & Dominant Set Clustering for Video Summarization” Multimedia Tools and Applications, Volume 44 , Issue 2 , September 2009, Pages: 161 - 186.


Digital Processing of Natural Signals


Research Activities

Radar Signal Detection and Characterization of Radar Clutter. SAR remote sensing and interferometry. Pattern recognition and Biometrics. Information Fusion, Super-resolution. Image processing techniques for Astro-particle Physics.

Teaching

Basic Electronics, Digital Signal & Image Processing, Informatics and Remote Sensing.

Recent R&D Projects

1. 2012-2014: National Action “Cooperation 2011”, JASON: “Joint synergistic and integrated use of eArth obServation, navigatiOn and commuNication technologies for enhanced border security”.2. 2010-2013: HERAKLEITUS II, “Person Psychophysical condition Identification using Infrared Imagery”. 3. 2012-2014: The “Landslide Vulnerability Model – LAVMO”, THALES, National Pro-ject.

Cooperations

1. CAST experiment at CERN (spokesperson Prof. K. Zioutas), with Dr. Axel Lindner (spokesperson of the ALPS experiment in DESY), Dr. Janusz Sylwester and Dr. Szymon Gburek/SPHINX mission, Academy of Sciences, Wroclaw, Poland, and Dr. Thomas Papaevangelou /saclay-Paris/France we search for parti¬cles candidates of dark matter and dark energy.2. Institute of Geophysics, Ecole Normale Superiere, Paris, Landslides monitoring (Dr. Pierre Briolle).3. AUG Ltd Signals, Toronto, Canada, Signal detection and Information fusion.4. National Observatory of Athens, Interferometric SAR (Olga Sykioti). 5. Department of Philology, University of Patras, Forensic Linguistics (Anna Roussou).

Selected Publications

• V. Anastassopoulos, G.A. Lampropoulos, A. Drosopoulos and M.Rey, ‘High Resolu-tion Radar Clutter Statistics’, IEEE Transactions on Aerospace and Electronic Systems, Vol. 35, No. 1, pp. 43-60, January 1999.• E.N. Zois and V. Anastassopoulos, ‘Morphological waveform coding for writer iden-tification’, Pattern Recognition, 33/3, pp. 385-389, 2000.• V. Tsagaris, V. Anastassopoulos and G. Lampropoulos, ‘Fusion of hyperspectral data using segmented PCT for color representation and classification’, IEEE Transac-

GROUP MEMBERS

Anastassopoulos VassilisProfessorElectronics LaboratoryPhysics [email protected]

PostDoc Student: Koukiou Georgia [email protected]

Postgraduate Students: Kouroupis George [email protected] Helen

Drunk person identification using infrared images


tions on Geosciences and Remote Sensing, Vol. 43, No. 10, pp. 2365-2375, 2005.• K. Zioutas, M. Tsagri, Y Semertzidis, T. Papaevangelou, T. Dafni and V. Anastas-sopoulos, ‘Axion Searches with Helioscopes and astrophysical signatures for axion(-like) particles’, New Journal of Physics, 11, 105020, 2009.• A. Panagiotopoulou and V. Anastassopoulos, “Super-resolution image recon-struction techniques: Trade-offs between the data-fidelity and regularization terms”, Information Fusion, 13, pp. 185–195, 2012.• G. Koukiou and V. Anastassopoulos, ‘“Drunk Person Identification Using Ther-mal Infrared Images”, International Journal of Electronic Security and Digital Forensics, 2012, 4, (4), pp. 229-243.

HINODE X-Ray image processing for dark matter particle search

Interferometric SAR processing for landslides monitoring

http://www.ellab.physics.upatras.gr/~anastassopouloshttp://scholar.google.gr/citations?user=BYcshrUAAAAJ&hl=en&oi=ao


Embedded Systems (ES) Group


Research Activities

The Embedded Systems (ES) group is working on the design and implementation of high performance control and real-time systems using microprocessors, micro-controllers, Field Programmable Gate Arrays (FPGAs) and Digital Signal Processors (DSPs), for telecommunication applications, and digital signal and image processing. It is also working on the design and testing of digital VLSI circuits and systems with an emphasis on computer arithmetic. Research is mainly focused on:

• Remote Controlled Embedded Systems. Systems for real-time digital signal and image processing that are controlled via Ethernet/Internet. Development of architec-tures for remote laboratories with emphasis in Signal Processing Systems with DSPs and in Computer Architecture with FPGAs.• Digital VLSI Circuits and Systems. High-speed arithmetic circuits, CPUs, DSP cores using VHDL/Verilog in FPGAs or ASICs. Low power testing of VLSI digital circuits. • Image processing and algorithm implementation concentrating on Image Segmen-tation, Image Coding and Computer Vision. Segmentation has been performed using a similarity measure proposed for this purpose. The measure is applied between different colored regions, while concepts of fuzzy clustering have been used. • Software/Hardware co-design for telecommunication applications especially fo-cused on real-time voice coding as well as on modems development using DSPs.• Control and Data Acquisition Systems. Systems based on microcontrollers are developed for a large variety of applications. • Voice Processing (LP/LD-CELP coding, non-linear filters, etc). New LPC algorithms have been proposed for real-time speech coding.

Infrastructures / Facilities

• 10 fully-equipped workstations for developing digital signal processing applica-tions using TI’s (Texas Instruments) developing platforms (DSKC6713, DSKC6416, VDP6437). • 10 fully-equipped workstations for embedded system development with VHDL/Ver-ilog using ALTERA’s developing platforms (DE2, DSP Dev. Kit Stratix II, DSP Dev. Kit Stratix II Prof. Edition). • 10 fully-equipped workstations for data acquisition and management system using developing platforms based on ATMEL’s microcontrollers. • Data acquisition laboratory equipped with NI’s (National Instruments) data acquisi-tion platforms along with LabVIEW and MATLAB software.

Collaborations

• Computer Engineering & Informatics Department, University of Patras, Greece.

GROUP MEMBERS

Zigouris EvangelosAssociate [email protected] DimitrisAssistant [email protected]

Vassalos EvangelosPhD, Post-Doc ResearcherKalantzopoulos AthanasiosPhD Candidate



1. E. Vassalos and D. Bakalis, “CSD-RNS-based Single Constant Multipliers”, Journal of Signal Processing Systems, Springer, vol. 67, no. 3, pp. 255-268, June 2012.2. D. Bakalis, H. T. Vergos and A. Spyrou, “Efficient Modulo 2n±1 Squarers”, Inte-gration, the VLSI Journal, Elsevier, vol. 44, no. 3, pp. 163-174, June 2011.3. D. Bakalis and H. T. Vergos, “Shifter Circuits for {2n+1, 2n, 2n-1} RNS”, Electron-ics Letters, IET, vol. 45, no. 1, pp. 27-29, 1 January 2009.4. X. Kavousianos, D. Bakalis and D. Nikolos, “Efficient Partial Scan Cell Gating for Low-Power Scan-based Testing”, ACM Transactions on Design Automation of Electronic Systems, ACM, vol. 14, no. 2, article no. 28, March 2009.5. Kalantzopoulos, E. Galetakis, C. Katsenos, & E. Zigouris,”An Interactive Remote Laboratory on Basic Computer Architecture Using Altera DE2 Board”, Internation-al Journal of Online Engineering, i-JOE, Vol. 9, No. 5, pp. 9-16, September 2013.6. D. Besiris & E. Zigouris, “Dictionary-based Color Image Retrieval using Multiset Theory”, Journal of Visual Communication and Image Representation, 2013, doi: http://dx.doi.org/10.1016/j.jvcir.2013.07.009.7. A. Kalantzopoulos, D. Karageorgopoulos & E. Zigouris, “Remotely Controlled Real-Time DSP Applications through Customized GUIs based on LabVIEW”, Inter-national Journal of Online Engineering, i-JOE, Vol. 6, Special Issue: REV2010, pp. 36-40, September 2010.8. G. Souliotis, N. Fragoulis, K. Giannakopoulos, D. Besiris & E. Zigouris, “Current-mode wave field programmable analogue arrays”, International Journal of Circuit Theory and Applications, Vol. 38, pp.331–341, 2010.9. M. Petouris, A. Kalantzopoulos & E. Zigouris, “An FPGA-based Digital Camera System Controlled from an LCD Touch Panel”, Proc. of the ISSCS 2009, 9th Inter-national Symposium on Signals, Circuits & Systems, ISSCS 2009 Iasi, Romania, 9-10 July, 2009.10. Kalantzopoulos,D. Markonis & E. Zigouris, “A Remote Laboratory for Real-Time Digital Image Processing on Embedded Systems”, International Journal of Online Engineering, i-JOE, Vol. 5, No. 4, pp. 24-29, November 2009.

Recent Projects

• [2011-2013] “Digital arithmetic circuits design for Residue Number System”, C. Caratheodory Programme, University of Patras (Coordinator: D. Bakalis)• [2009-2010] “Control and Communication with Data Acquisition Devices Inde-pendently of the Operating System”, Innovation Voucher, in Cooperation with Thyratron Ltd (Coordinator: E. Zigouris.


Laser Laboratory


Research Activities

Our research interests are related to ultrafast photophysics-photochemistry, non-linear optics, and optical fibers.

Ultrafast phenomena-photophysics

Ultrafast phenomena are the physical phenomena that occur in the femtosecondto picosecond time scale. Particularly we are interested in studying the ultrafast dynam-ics of phenomena such as electron or proton transfer, energy transfer, vibrational or solvent relaxation etc. We study both isotropic and anisotropic excited state dynam-ics. For the study of longer excited state dynamics, such as population fluorescence decay, molecular rotations in viscous environments etc. we also apply time resolved spectroscopy in the 10ps - 100 ns timescale. We are interested in the photophysi-cal ultrafast study of organic molecules, self-assembled systems, multi-branched molecules, nanocomposites and biomaterials.

Nonlinear Optics

We work on the study of non-linear optical phenomena (e.g. two photon absorption) in new organic materials. Additionally, we are interested inthe development of new techniques for studying nonlinear optical properties in order to simplify experimen-tal efforts and mathematical calculations. Materials such as bipolar, quadrupolar and octupolar organic systems with a variety of electron donating and withdrawing groups are of our interest. In addition, we apply two-photon absorption in order to develop micro-nano-structures in three-dimensions made by photopolymerization or photobleaching. This mask-less, direct laser writing technique is based on the confinement of TPA to a very small volume (a few hundreds of femtoliters).

Optical Fibers

The development of fiber lasers as well as of fiber optical sensors based on fiber Bragg Gratings and photonic crystal fibers are our research interests on this field.

Facilities

Femtosecond fluorescence upconversion spectroscopy (excitation at 800, 400 or 267nm, detection at the visible and NIR, temporal resolution 100 to 140fs, lifetime range 100fs to 2ns).Two-Photon Excited Fluorescence Spectroscopy (TPEF), (excitation spectral range 740-850nm, excitation pulse duration <80fs).Fully automated three-dimensional microfabrication set-up.Time Correlated Single Photon Counting Spectroscopy (excitation at 405nm, detec-tion at 200nm-850nm, temporal resolution down to 10 ps with deconvolution, lifetime range 10ps to 100ns).Optical Fiber testing set-up with broadband light.

GROUP MEMBERS

FacultyVasilis Giannetas [email protected] Fakis [email protected] Persephonis Retired [email protected]

Ph.D. studentsMaria-Anna Dori

M.Sc. studentsKostas SeintisDamianos AgathagellouEvripidis MichailNikolaos DroserosNiki Papachristou

URL: www.physics.upatras.gr/laserlab


Equipment

Three optical tables with vibration dumper systems, a Ti:Sapphire femtosecond laser, a Time Correlated Single Photon Counting set-up, a high power cw Nd:YVO4 laser, Helium-Neon lasers, a laser beam profile analyzer, digital oscilloscope, spectrum analyzer, lock-in amplifier, data acquisition and automation systems, single photon counters, photomultipliers, avalanche photodiodes, galvanometric mirrors, monochromators, diode arrays, Erbium Doped Fiber Amplifiers, Super continuum laser, optical spectrum analyzer, splicer, cleavers, optical loss test set and a great variety of optical, optomechanical and motorized positioning equip-ment.

Research Programs

Our group has recently been funded by the following programs:PYTHAGORAS I and II, (EPEAEK II)HERACLITUS, (EPEAEK II)PEP Western Greece (GSRT)KARATHEODORIS (Univ. of Patras)PENED ’99 (GSRT)

External Collaborations

University of Geneva (Switzerland), Technische Universität Berlin (Germany), Comenius University Bratislava (Slovakia), Institute of Chemistry of Taipei (Tai-wan), Izmir Katip Celebi University (Turkey), Technical Institute of Patras, NCSR Demokritos, University of Patras (Departments of Chemistry and Computer Engineering and Informatics).

Selected Publications

1. “Two-photon polymerization of a diacrylate using fluorene photoinitiators-sen¬sitizers” I. Fitilis, M. Fakis, J. Polyzos, V. Giannetas, P. Persephonis, J. Photo-chem. Photobiol. A: Chem. 215 (2010) 25–30 2. “Femtosecond Decay and Electron Transfer Dynamics of the Organic Sensitizer D149 and Photovoltaic Performance in Quasi-Solid State Dye-Sensitized Solar Cells” M. Fakis, E. Stathatos, G. Tsigaridas, V. Giannetas, P. Persephonis, J. Phys. Chem. C 115 (2011) 13429-13437 3. “Benzothiazoles with Tunable Electron-Withdrawing Strength and Reverse Polarity:A Route to Triphenylamine-Based Chromophores with Enhanced Two- Photon Absorption” P. Hrobarik, V. Hrobarikova, I. Sigmundova, P. Zahradnik, M. Fakis, I. Polyzos, P. Persephonis, J. of Org. Chem. 76 (2011) 8726–8736 4. “Electron injection studies on TiO2 nanocrystalline films sensitized with flu¬orene dyes and photovoltaic characterization. The effect of co-adsorption of a bile acid derivative. “ M. Dori, K. Seintis, E. Stathatos, G. Tsigaridas, T.-Y. Lin, J. T. Lin, M. Fakis, V. Giannetas, P. Persephonis, Chem. Phys. Let. 563 (2013) 63–69 5. “A time resolved fluorescence and quantum chemical study of the solar cell sensitizer D149” M. Fakis, P. Hrobàrik, E. Stathatos, V. Giannetas, P. Persephonis, Dyes and Pigments 96 (2013) 304-3126. “Highly efficient and unidirectional energy transfer within a tightly self-assem-bled host–guest multichromophoric array” N. Karakostas, I. M. Mavridis, K. Sein-tis, M. Fakis, E. N. Koini, I. D. Petsalakis and G. Pistolis, Chem. Commun. accepted (2013) (MANUSCRIPT ID: CC-COM-10-2013-048076.R1)

S E C T I O N O F A P P L I E D P H Y S I C S

Laboratory Of Atmospheric Physics (LAPUP)


Research Activities

The main research activities of the LAPUP include:• Measurements, quality control, processing and homogenization of meteorological and environmental time series. • Stable isotopes (δ18Ο & δ2Η) in rain and in atmospheric water vapor.• Ultraviolet radiation: Measurements, modeling and biological dose rates.• Solar Radiation: Measurements, modeling and solar energy.• Artificial intelligence methods applied to atmospheric and environmental physics problems.• Weather and atmospheric pollution forecasting modeling.

Infrastructure - Facilities

• Fully equipped chamber for indoor calibration of pyranometers.• Two automated weather stations measuring ambient temperature and relative humid-ity, wind speed and direction, atmospheric pressure, and precipitation amount and rate.• System for hygrometer calibration using saturated salts solutions.• An automated radiometric station including a) instrumentation for the measurement of global, direct and diffuse horizontal solar irradiance (station of the Hellenic Network of Solar Energy, www.helionet.gr) and sunshine duration and b) sky cameras.• Twelve pyranometers for the measurement of global horizontal solar irradiance (sta-tions of the Hellenic Network of Solar Energy, www.helionet.gr)• A narrowband multifilter radiometer NILU-UV6 for UV and PAR measurements (station of the Greek National UV Network, www.uvnet.gr).• Three multi-core PC workstations for detailed weather forecast and air pollution modeling.• A computer facility for near real time collection of satellite images (EUMETCAST system)

Recent publications

• Determination of measuring sites for solar irradiance based on cluster analysis of satel-lite – derived cloud estimations, A. Zagouras, A. Kazantzidis, E. Nikitidou, A. A. Argiriou, , Solar Energy, 97:1-11, 2013 • The aerosol forcing efficiency in the UV region and the estimation of single scattering al-bedo at a typical West European site, E. Nikitidou, A. Kazantzidis, V. De Bock, H. De acker, , Atmospheric Environment, 69, 313-320, 2013 • Weather maps classification over Greek domain based on isobaric line patterns, Atha-nassios Zagouras, Athanassios A. Argiriou, George Economou, Spiros Fotopoulos, Helena A. Flocas, , Theoretical and Applied Climatology, 2013 • Skin Cancer Risks Avoided by the Montreal Protocol—Worldwide Modeling Integrat-ing Coupled Climate-Chemistry Models with a Risk Model for UV, Arjan van Dijk, Harry Slaper, Peter N. den Outer, Olaf Morgenstern, Peter Braesicke, John A. Pyle, Hella Garny, Andrea Stenke, Martin Dameris, Andreas Kazantzidis, Kleareti Tourpali, Alkiviadis F. Bais, Photochemistry and Photobiology, 89: 234–246, 2013 • On the differences of ultraviolet and visible irradiance calculations in the Mediterranean basin due to model- and satellite-derived climatologies of aerosol optical properties, E. Nikitidou, A. Kazantzidis, , International Journal of Climatology, DOI: 10.1002/joc.3638, 2012 • On the differences of ultraviolet and visible irradiance calculations in the Mediterranean basin due to model- and satellite-derived climatologies of aerosol optical properties, E.

GROUP MEMBERS

Athanassios A. ArgiriouPhysicist (U. Patras) - D.E.A. (I.N.P. Grenoble) - Ph.D. (Univ. Aix-Marseille 1), As-sociate Professor (Head of the LAPUP)Andreas KazantzidisPhysicist - M.Sc. - Ph.D. (Ar-istotle University of Thessa-loniki), Assistant ProfessorAnastasia RaptiPhysicist - Ph.D. (University of Patras), Lecturer with tenureIoannis KioutsioukisPhysicist - M.Sc. - Ph.D. (Aristotle University of Thes-saloniki), Lecturer, appoint-ment pending.

There are also currently 5 Ph.D. Students. The staff also includes sev-eral research associates with short term contracts depending on the number of research projects.

www.atmosphere-upatras.grwww.weather.upatras.gr


Nikitidou, A. Kazantzidis, , International Journal of Climatology, DOI: 10.1002/joc.3638, 2012 • Homogenization of mean monthly temperature time series of Greece, Anna Mamara, Athanassios A. Argiriou, Manolis Anadranistakis, , International Journal of Climatology, Published online, 2012 • An advanced method for classifying atmospheric circulation types based on prototypes connectivity graph, Athanassios Zagouras, Athanassios A. Argiriou, Helena A. Flocas, George Economou, Spiros Fotopoulos, , Atmospheric Research, 118, 180-192, 2012 • Cloud detection and classification with the use of whole-sky ground-based images, A. Kazantzidis, P. Tzoumanikas, A.F. Bais, S. Fotopoulos, G. Economou, , Atmospheric Research, 113, 80-88, 2012 • Reverse flood routing with the inverted Muskingum storage routing scheme, A. D. Kous-sis, K. Mazi, S. Lykoudis, A. A. Argiriou, , Nat. Hazards Earth Syst. Sci., 12, 217-227, 2012

Recent projects

• Stable isotopes in biospheric – atmospheric – earth system research (COST Action ES0806 - SIBAE). European Science Foundation, 5/2009 –4/2013, www.sibae.ethz.ch/cost-sibae/• Weather Intelligence for Renewable energies (WIRE, COST Action ES1002), Euro-pean Science Foundation, 11/2010 – 11/2014, www.wire1002.ch• Hellenic Network of Solar Energy (General Secretariat of Research and Technology, Greece), 1/2011 – 3/2013, www.helionet.gr• Contribution of Emission Sources on the Air quality of the Port-cities in Greece and Italy. ETCP GREECE – ITALY 2007-2013 – European Commission, 11/2011 – 10/2013, www.cesapo.upatras.gr• ENvironmental Optimization of IRrigation Management with the Combined uSe and Integration of High PrecisIon Satellite Data, Advanced Modelling, Process Control and Business Innovation , FP7-ENV Project ENORASIS, Grant Agreement 282949, 01/ 2012 – 12/2014, www.enorasis.eu/• Modelling approach to determine the duration and intensity of sunlight exposure required to maintain and achieve adequate vitamin D status in winter in ‘at risk’ population groups, Subcontractor, University of Manchester, funded by Department of Health, UK• Direct Normal Irradiance Nowcasting methods for optimized operation of concen-trating solar technologies, FP7-Energy project DNICast, Grant Agreement 608623, 10/2013 – 9/2017

Participation in scientific networks and international collaborations

The LAPUP is an associate member of the Navarino Environmental Observatory (NEO) and of the National Networks for the measurement of solar and ultraviolet radiation.

The LAPUP collaborates with numerous of foreign universities and research insti-tutes. Selected collaborations: Ecole Normale Superieure, Observatoire Mediterra-neen de l’ Energie, Association pour la Recherche et le Developpement des Methodes et Processs Industrielles – ARMINES, NOVELTIS SAS (France), Rheinisches Institut für Umwelt-Forschung an der Universität zu Köln E.V., Deutches Zentrum für Luft – und Raumfahrt E.V., Leibniz Institut für Troposphärenforschung E.V. (Germany), International Atomic Energy Agency (Austria), ISAC-CNR, University of Salento (Italy), Sveriges Meteorologiska och Hydrologiska Institut, Stockholms Universitet (Swe-den), Centro de Invesrigaciones Energeticas, Medioambientales y Technologicas (Spain), Eidgenössisches Departement des Innern, Scola Universitaria Professionale Della Svizzera Italiana, Physikalisch-Meteorologisches Observatorium Davos/World Radiation Center (Switzerland), the Cyprus Institute Limited (Cyprus), University of Manchester (UK), Aristotle University of Thessaloniki, National Observatory of Athens, Academy of Athens (Greece).

Annual climatological solar energy values, for GHI (A), DNI (B) and the irradiance incident on a tilted surface (C). Units are given in kWh/m2.

High resolution δ18O and δ2H maps produced by ISOGRIDS, a tool for gen-erating gridded maps of stable isotopes in precipitation, officially distributed by the International Atomic Energy Agency (http://www-naweb.iaea.org/napc/ih/IHS_resources_sampling.html#isogrids)


Renewable Energy Research Group


Research Activities

SOLAR ENERGY MATERIALS AND DEVICES: The Renewable Energy Laboratory has con-siderable experience in the design, fabrication and testing of solar energy materials and devices for photovoltaic and solar thermal applications. We specialize in the development of thin film semiconductors (WO3, TiO2, ZnO, CdS, CdTe, MoO3) for dye sensitized and thin film solar cells. We have the capability of producing thin films in high vacuum conditions using different techniques, such as electron gun deposition and thermal evaporation. A large variety of films (metals, dielectrics, oxides, sulfides) can be deposited on virtually any type of substrate (glass, silicon, quartz, polymer), with thickness ranging from the sub-nm to several μm. Sol-gel, doctor blade and electrochemical deposition techniques are also used. We have also acquired expertise in the testing of solar energy devices in outdoor conditions. Our laboratory has played an integral role in the design and construc-tion of the first Greek Solar Car, “Hermes” and is the principal scientific collaborator of a Greek micromorphic Si photovoltaic facility.ENERGY & BUILDINGS: Original large surface electrochromic devices for smart window applications have been constructed and thoroughly tested. Photo-electrochromic devices, a combination of the photovoltaic and electrochromic technologies are currently under development. We have considerable experience in the measurement of thermo-physical properties of building components.HYDROGEN AND FUEL CELLS: Micro and nano scale thin films on various substrates for fuel cell (solid electrolyte YSZ) and H2 production applications have been studied and opti-mized. Electrochemical techniques such as electrodeposition have been used to produce binary and ternary alloys and inter-metallic compounds.

Infrastructure-facilities:

• High vacuum pumping systems and vacuum chambers for the preparation of thin films with thermal evaporation and electron beam deposition. Capability for sequential deposi-tion of up to four different materials and of substrate rotation.• UV-VIS Spectrophotometers for measuring optical properties • Apparatus for the measurement of spectral response (IPCE) and external quantum ef-ficiency of photovoltaics.• AM1.5G solar simulator for the measurement of I-V characteristics of photovoltaics.• Stylus Profilometer for the measurement of thin film thickness • Glove Box for sample treatment and storage in inert environment • Potensiostat- galvanostat for electrochemical experiments and electrodeposition of thin films• Test Cell for the experimental testing of building components• Outdoor testing facilities (test rigs, data loggers, IV tracers, pyrometers, thermocouples).

Collaborations:

• European Universities: Lund (Sweden), UMIST (UK), Ulster (UK), Jagellonian (Poland),

GROUP MEMBERS

P. YianoulisRetired [email protected]. LeftheriotisAssistant [email protected]

Post-doctoral researchers: M. GiannouliG. Syrrokostas

PhD students: E. KoubliG. Koutsourakis


Siberian Federal University (SFU), Russia. • Greek Universities- institutions: NCSR Demokritos, National Technical Univ. Athens, Univ. of Western Greece, FORTH/ICE-HT, Chemistry and Civil Engineering depart-ments of Patras University• Corporate partners: Pilkington, BP Solar, Optronics, Patsis Glass, Uniglass, Helio-sphera

Recent publications:

• G. Leftheriotis, E. Koubli, P. Yianoulis: “Combined electrochromic-transparent conducting coatings consisting of noble metal, dielectric and WO3 multilayers”, Solar Energy Materials & Solar Cells 116 (2013) 110–119.• G. Leftheriotis, G. Syrrokostas and P. Yianoulis: “Photocoloration efficiency and sta-bility of photoelectrochromic devices”, Solid State Ionics 231 (2013) 30–36.• G. Syrrokostas, A. Siokou, G. Leftheriotis and P. Yianoulis: “Degradation mecha-nisms of Pt counter electrodes for dye sensitized solar cells”, Solar Energy Materials & Solar Cells 103 (2012) 119–127• G. Leftheriotis, G.Syrrokostas, P.Yianoulis ““Partly covered” photoelectrochromic devices with enhanced coloration speed and efficiency”. Solar Energy Materials & Solar Cells 96 (2012) 86-92• M. Giannouli, G. Leftheriotis “The effect of precursor aging on the morphology and electrochromic performance of electrodeposited tungsten oxide films”. Solar Energy Materials & Solar Cells 95 (2011) 1932–1939.

Recent Projects

• GSRT “EXCELLENCE” Project: “Building integrated solar cooling of windows and patios with innovative nano-composite materials”. Acronym: COOL NANO, 2012- 2015. Principal Investigator: Dr D. Karamanis, University of Western Greece.

• GSRT “EXCELLENCE” Project: “Design and development of new polymer and hybrid electron donors for application in organic photovoltaics”. Acronym: DENEA, 2012-2015. Principal Investigator: Prof J. Kallitsis, Chemistry, Patras Universtiy.

• MINEDU “THALES” Project: “Development and study of innovative Zinc Oxide (ZnO) nano-structures for application in nano-photonics and solar energy: Experimental and theoretical approach”. Acronym: NA(Z)NOWIRES, 2012-2015. Coordinator: Dr S. Yianopoulos, FORTH/ICE-HT

• GSRT “COOPERATION” Project: “Processes for the development of new photovoltaic Silicon nano-materials”. Acronym: TFT Solar, 2011-2014. Coordinator: Dr D. Tsouka-las, NCSR DEMOKRITOS.

• Support of Research Services, Technology and Innovation of Patras University: “Development of photo-electrochromic devices for the dynamic solar control of build-ings”, 2011-2014, co-funded by the EU and the Greek Government.


Solar Energy Research Group


Research Profile

The research laboratory for solar energy systems and applications (SEL) is established at the Applied Physics Sector of Physics Dept, Univ. of Patras and is active in education and research for 35 years. The work of Solar Energy Research Group includes studies, experiments and projects on solar energy conversion systems in the built, industrial and agricultural sectors. The most widely known work is on the Integrated Collector Storage (ICS) solar water heaters, Hybrid Photovoltaic/Thermal systems, Static concentrators and Effective Integration with aesthetic consideration of solar energy systems and other Renewable Energy Sources (RES) to buildings. There has been established National and International collaboration with research groups in Universities and Research Centers and have been performed 10 National and 8 EC funded research projects on solar energy conversion systems. From this research more than 180 papers in International Journals and in the Proceedings of International and National Conferences have been published.

Research Activities:

• Flat plate and vacuum tube solar thermal collectors for liquid and air heating • Flat plate and vacuum tube thermosiphonic and Integrated Collector Storage (ICS) solar water heaters • Solar thermal collectors with colored absorbers for aesthetic integration to buildings • Solar thermal collectors and photovoltaics with booster reflectors to enhance energy output• Solar thermal collectors with static or tracking CPC or PTC reflectors and Fresnel lenses • Effective application of c-Si, pc-Si, a-Si, CIS, CdTe, OPV and other type of photovoltaics • Hybrid Photovoltaic/Thermal (PV/T or PVT) systems for simultaneous electricity and heat production • CPV (Concentrating photovoltaics) and CPVT (Concentrating PVT) solar energy systems • Energy consumption and solar control of building atria and greenhouses with Fresnel lens systems • Integration of passive and active solar systems and other renewable energy systems (RES) to buildings • Application of solar energy and other RES to the built, industrial and agricultural sectors • Effective combination of solar energy and other RES towards Zero Energy Buildings (ZEB) • Effective integration of solar thermal, photovoltaics and PV/T collectors on greenhouses

Infrastructure

• Test field for Solar Thermal Collectors, Thermosiphonic Units and ICS systems• Test field for measurements of Photovoltaic panels and Hybrid PV/T systems• Optical and Thermal measurements of passive/active solar energy systems• Test field for measurements of Hybrid PV - Small Wind Turbine systems

Collaboration

SEL has a creative collaboration with many Universities and Research Centers and among them with: Centre of Renewable Energy Sources and Saving (CRES, Athens),

GROUP MEMBERS

Yiannis TripanagnostopoulosProfessor [email protected] SouliotisPost Doc Researcher

2 M.Sc Students4 B.Sc Students


Agricultural University of Athens, University of Ulster, Belfast (UK), University of Lleida (Spain), Universitat Politecnica de Catalunya, Barcelona (Spain), Universitat Rovira I Virgili, Tarragona (Spain), Technical University of Munich (TUM) (Germany), Faculty of Agriculture, University of Bari (Italy), Warsaw University of Technology (Poland), Kra-kow University of Technology (Poland), University of Nis (Serbia), Cyprus University of Technology (CUT), Limassol (Cyprus), CINVESTAV 3D, CINVESTAV, Querétaro (México).

Visits

A number of Scientists, Researchers and University Professors have visited SEL for collaboration and among them: Prof. Brian Norton and Prof. Philip Eames, from UK, Prof. Jeffrey Gordon, from Israel, Prof. Terry Hollands, Head of ISES, from Canada, Prof. Dorota Chwieduk, Polish ISES Section, Dr Riccardo Battisti, from Italy, Dr Car-men Rocamora-Osorio, from Spain, Prof Mitco Stoev, from Bulgaria, Prof Tomislav Pavlovic, from Serbia, Prof.Yuri Vorobiev, from Mexico, Prof. Jaume Roset and Fidel Franco, from UPC, Barcelona, Spain, Prof. Daniel Chemisana, from Univ. of Lleida, Spain, Prof. Soteris Kalogirou, from TUC, Cyprus.

Recent Projects

• “Building Implementation of Photovoltaics with Active Control of Temperature (Building IMPACT)”. JOULE «JOR3-CT98-0308» EC Project (1998–2000).• “PV CATAPULT”. 6th Framework EC Program (2003-2006). • “Design and performance improvement of CPC type ICS solar water heaters“. Greek/Tunisia Bilateral Project (2006-2008).• “Development and Experimental Evaluation of a Two Stage Autonomous Solar Organic Rankine Cycle Reverse Osmosis Desalination System” Synergasia, Greek Project (2010-2013).• “Building-integrated fibre-reinforced solar technology - BFIRST”, EC Project 296016 (2012-16)• “Building Integrated Solar Thermal Systems - BISTS” COST TU1205 EC Project (2013-2018)

Recent Publications

• Y. Tripanagnostopoulos, M. Souliotis and Th. Nousia, “Solar Collectors with Colored Absorbers”, Solar Energy 68, No 4, pp 343–356 (2000).• Y. Tripanagnostopoulos, Th. Nousia, M. Souliotis and P. Yianoulis, “Hybrid Photovol-taic/Thermal Solar Systems”, Solar Energy 72, No 3, pp 217–234 (2002).• Y. Tripanagnostopoulos, Ch. Siabekou and J. K. Tonui. “The Fresnel lens concept for solar control of buildings”. Solar Energy 81 (5), pp. 661-675, (2007).• Y. Tripanagnostopoulos. “Aspects and improvements of hybrid photovoltaic/thermal solar energy systems”. Solar Energy 81 (9), pp. 1117-1131, (2007).• J. K. Tonui and Y. Tripanagnostopoulos. “Performance Improvement of PV/T solar collectors with natural air flow operation”. Solar Energy 82 (1), pp. 1-12 (2008).• M. Souliotis, S. Kalogirou, Y. Tripanagnostopoulos. “Modelling of an ICS solar water heater using Artificial Neural Networks and TRNSYS”. Renewable Energy, 34, (5), pp. 1333–1339, (2009).• M. Souliotis, P. Quinlan, Y. Tripanagnostopoulos, M. Smyth, A. Zacharopoulos, M. Ramirez, P. Yianoulis. “Heat retaining integrated collector storage system with asym-metric CPC reflector”. Solar Energy, 85, (10), pp. 2474-2487, (2011).• Y. Tripanagnostopoulos. “Photovoltaic/Thermal solar collectors” Comprehensive Renewable Energy, 3.08, pp. 255-300, (2012). • M. Souliotis, D. Chemisana, Y. G. Caouris, Y. Tripanagnostopoulos. “Experimental study of integrated collector storage solar water heaters”. Renewable Energy, 50, pp. 1083-1094 (2013).


Laser, Non-Linear And Quantum Optics Research Group


Research Activities

Novel nano-sized (organic, inorganic and hybrid organic-inorganic) materials and nano-structures are expected to play an important role in a variety of next-generation photonic applications and devices ranging from telecommunications and solar-energy harvesting to bio-photonics. However, fulfilling the potential of these materials relies on understand-ing the molecular details and/or structural characteristics that currently limit their overall efficiency with regards to performance, processability and stability. Our research efforts in photonics are focused in two directions: characterization of the nonlinear optical proper-ties of novel photonic materials, and unravelling and eventually controlling the underlying photophysical mechanisms in order to tailor the nonlinear optical properties of these materials towards the needs of specific applications.• Nonlinear Optics & Nonlinear Optical Materials: it is among our goals to establish phenomenological correlations between the structural characteristics of the materials/molecular systems and their macroscopic NLO response. • Some materials of interest: graphene and derivatives, fullerenes and derivatives, rotaxanes, carbon based nanostructures (carbon dots, carbon nanodiamonds, etc.), azo-benzenes, metallic nanoparticles, organic-inorganic hybrid materials, metal dithiolene complexes, etc.• Laser Spectroscopies: MultiPhoton Ionization spectroscopy (MPI), Resonance Enhanced Multiphoton Ionization spectroscopy (REMPI), Time-Of-Flight MultiPhoton Ionization spec-troscopy (TOF-MPI), Photo-electron spectroscopy (PES), Molecular spectroscopy, Coher-ent Anti-Stokes Spectroscopy (CARS), Four Wave Mixing (FWM) spectroscopies, Third Harmonic Generation (THG), Second Harmonic Generation (SHG). • Laser Induced Breakdown Spectroscopy (LIBS), Laser produced plasmas: spectroscopy and analytical/industrial applications, Laser based combustion diagnostics. • Nano-structured materials by laser ablation. • Nonlinear atom-laser interactions: experimental and theoretical studies of the internally generated parametric emissions from two photon excited alkaline atoms, quantum inter-ference effects and competition between the channels involved in the interaction, aiming to develop EUV sources, lasers without population inversion (LWI) and slowing of light. • Development of VUV and EUV lasers based on rare gas dimmers and mixtures.

Infrastructure

• Laser sources: two ns Nd:YAGs and 35 ps Nd:YAG operating at 1064, 532 and 355 nm, ns OPO laser (215-2300nm), excimer laser, home-made dye lasers, <50fs Ti-sapphire laser with amplifier [to be installed].• Spectrographs covering from NIR to VUV.• Optics (lenses, mirrors, polarizers, beam splitters, attenuators, etc.) for NIR, Visible, UV, VUV. • Fast gated ICCD detectors for VUV and UV-Vis-NIR, several PMTs, photodiodes, power meters.• Digital oscilloscopes (4 and 2 GHz).• Electronic equipment for signal recovering (Boxcars, Lock-ins, pulse generators).

GROUP MEMBERS

S. [email protected]@iceht.forth.grT. EfthimiopoulosProfessor [email protected]

Postdoctoral fellow:P. [email protected]. [email protected]

PhD candidates:M. [email protected]. [email protected]. [email protected]

MSc students:D. [email protected]. [email protected]. [email protected]. [email protected]

www.LNLQOL.upatras.gr


• Vacuum equipment (rotary and turbo pumps, mechanical accessories, etc.).• Experimental workstations: Z-scan, Optical Kerr Effect (OKE), Pump-probe, Second and Third Harmonic Generation (under construction).

Collaborations

University of Cambridge (UK), Weizmann Institute of Science (Israel), University of Trieste (Italy), University of Bologna (Italy), University of Namur (Belgium), University of Bourgogne (France), University of Paris Sud-Orsay (France), University of Angers (France), University of Erlangen-Nurnberg (Germany), University of Cyprus (Cyprus), University of Vilnius (Lithuania), University of Cagliari (Italy), Tampere University of Technology (Finland), University of Patras (Department of Materials Science), National Hellenic Research Foundation, University of Ioannina, TEI of Crete, FORTH/ ICE-HT, FORTH/IESL.

Funding

EU (IST, COST), Ministry for National Education, Research and Technology: HERAKLEI-TUS I & II and THALIS, Cyprus Research Organization Selected Publications• “NLO response of photo-switchable azobenzene-based materials”, N. Liaros, S. Couris, L. Maggini, F. De Leo, F. Cattaruzza, C. Aurisicchio and D. Bonifazi, ChemPhy-sChem, 14, 2961-2972, (2013).• “Fluoro-graphene: Nonlinear optical properties”, N. Liaros, A.B. Bourlinos, R. Zboril, S. Couris, Opt Express, 21, 21027-21038, (2013).• “Synthesis, characterization and non-linear optical response of organophilic carbon dots”, A. B. Bourlinos, M. A. Karakassides, A. Kouloumpis, D. Gournis, A. Bakandrit-sos, I. Papagiannouli, P. Aloukos, S. Couris, K. Hola, R. Zboril, M. Krysmann, E. P. Giannelis, Carbon, 61, 640-643 (2013).• “Nonlinear Optical Properties and Broadband Optical Power Limiting Action of Graphene Oxide Colloids”, N. Liaros, P. Aloukos, A. Bakandritsos, T. Szabo, R. Zboril, S. Couris, J. Phys. Chem. C, 117, 6842–6850, (2013). • “Femtosecond Laser Induced Breakdown for Combustion Diagnostics”, M. Kotzagi-anni and S. Couris, Appl. Phys. Lett. 100 (26), art. no. 264104 (2012).• “Doxorubicin Nanocarriers Based on Magnetic Colloids with a bio-Polyelectrolyte Corona and High Non-Linear Optical Response: Synthesis, Characterization and Properties”, A. Bakandritsos, G. Mattheolabakis, T. Szabo, V. Tzitzios, D. Kouzoudis, S. Couris, K. Avgoustakis, Adv. Funct. Mater. 21 (8), 1465-1475, (2011). • “Photophysics and transient nonlinear optical response of donor–[60]fullerene hybrids”, P. Aloukos, S. Couris, D. Guldi, C. Sooambar, A. Mateo-Alonso, D. Bonifazi, M. Prato, J. Mater. Chem., 21 (8), 2524-2534, (2011).• “Optically active spherical Polyelectrolyte Brushes with a Nanocrystalline Magnetic Core”, A. Bakandritsos, N. Bouropoulos, R. Zboril, N. Boukos, K. Iliopoulos, S. Couris, Adv. Funct. Mater. 18 (11), 1694-1706 (2008).• “Efficient Modulation of the Third Order Nonlinear Optical Properties of Fullerene Derivatives”, A. Mateo-Alonso, K. Iliopoulos, S. Couris, M. Prato, J. Am. Chem. Soc. 130, 1534-1535, (2008).• “Third-order nonlinear optical response of gold island films”, E. Xenogiannopoulou, K. Iliopoulos, S. Couris, T. Karakouz, A. Vaskevich, I. Rubinstein, Adv. Funct. Mater. 18 (8), 1281-1289, (2008).

SECTION OF THEORETICAL AND MATHEMATICAL PHYSICS, ASTRONOMY AND ASTROPHYSICS

Observational Astrophysics Research Group


Research Activities

• Binary and multiple systems of stars.

CCDobservations of eclipsing binaries, cataclysmic variables, detection of new variables, longterm (monitoring) projects of variability and follow-up ground based observations as support to space observations, detection of circubinary extrasolar planets (DWARF project). Analysis of light and of period variations of close and spotted binary stars, search and study of multiple systems.Development of neural networks in order to apply the concept of Eclipsing Binaries with Artificial intelligence (EBAI) that aims to provide automated estimates of principal param-eters for thousand of eclipsing binaries from large survey data bases (KEPLER, OGLE, ASAS)

• Interstellar Medium & Active Galactic NucleiDetection and study of large-scale faint Supernova Remnants (SNRs).Study of the Morphology of Planetary nebulae (PN) Photometric monitoring of the variability of Active Galactic Nuclei (AGN)Study of the complex structures HII regions

• Development and Applications of Novel Instrumentation and Experimental Methods in Astroparticle Physics

Construction, operation and signal processing of the HELYCON scintillation detectors for the HELYCON “HEllenic LYceum Cosmic Observatories Network” project. HELYCON is a cosmic ray telescope which utilizes, instead of light, extensive air showers produced when cosmic rays interact with the earth atmosphere, constructed at Physics Laboratory of the Hellenic Open University.

Facilities and Equipment

The “Mythodea” Observatory at Patras University houses two modern telescopes (a CELESTRON 14΄΄ Schmidt Cassegrain and a MEADE 12΄΄) on computerized Paramount Equatorial Mounts Additional resources include a full range of computer facilities for data reduction and analysis, in LinuX/Windows environment, a weather station, image pro-cessing facilities and numerous portable telescopes. On-site telescope instrumentation includes CCD computer imaging systems (SBIG ST-10XME and ST7XME CCD cameras). Students receive hands-on training with this equipment and are actively involved in the collection and interpretation of research data (undergraduate and postgraduate level).Off-Site/ FacilitiesThe Aristarchos telescope at Helmos Observatory is one of the principal research facilities for the group since they have a 10% share of observing time on this 2.3 meters optical telescope, the largest in Greece. The University of Patras is a co-funding partner in the construction of the Aristarchos Transient Spectrometer (ATS).

GROUP MEMBERS

Christos Goudis ProfessorDirector of Institute of As-tronomy and Astrophysics (IAA) (2001-2011)[email protected]@astro.noa.grP.-E ChristopoulouAssistant [email protected]

3 PhD students3 MSc students

Collaborators:P. HantziosSenior Researcher, IAASARS, Head of Helmos [email protected]. J. AlikakosPostdoctoral Researcher, IAASARS, Support astrono-mer/Telescope Operator at Helmos [email protected]


Collaborations

• Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing (IAASARS) of the National Observatory of Athens (NOA)• Astronomical Institute of the Slovak Academy of Sciences• Physics Laboratory of the Hellenic Open University

Recent projects

• Participating to the project DWARF: a new international observational campaign, DWARF, aimed at detection of circumbinary extrasolar planets using the timing of the minima of low-mass eclipsing binaries (PI: Dr Th. Pribulla & Dr. M. Vanko)• THALIS II ASTRONEU 2013

Recent publications

Christopoulou, P.-E.& Papageorgiou, A. “An Extensive Analysis of the W UMa Type Binary FI Boo” Astronomical Journal, in press, (2013)Christopoulou, P.-E., Papageorgiou, A., Vasileiadis, T., Tsantilas, S., “A Holistic View of the W UMa Type TY Boo”, Astronomical Journal, 144, p.149, (2012)Pribulla , T., Vanko, M., Ammler-von Eiff, M., Andreev, M., Aslantürk, A., Awadalla, N., and 50 coauthors (incl. Christopoulou, P.-E., Papageorgiou), “The Dwarf project: Eclipsing binaries - precise clocks to discover exoplanets”, Astronomische Nach-richten, Vol.333, Issue 8, p.754. (2012)Alikakos, J., Boumis, P., Christopoulou, P. E., Goudis, C. D., “Discovery of optical candidate supernova remnants in Sagittarius”, Astronomy & Astrophysics, 544, p.140, (2012)Christopoulou, P.-E., Papageorgiou, A., Kleidis, S., Tsantilas, S., “The First Photometric Study and Orbital Solution/Period Analysis of the Misclassified Binary System V380 Cas”, Astronomical Journal, 143, p.30 (2012)

Named after the homonymous NASA “2001 Mars Odyssey” choral symphony by the Greek composer Vangelis Papathanassiou, Honor-ary Doctor of Physics Department, University of Patras.


Astroparticle PhysicsResearch Group


Research Activities

CAST experiment at CERN. The Physics department of the University of Patras, is the only greek institution that provides the leadership for an international collaboration at CERN of about 70 scientists since 2005. CAST is the only astroparticle physics experiment of CERN at CERN taking data since 2000.CAST is searching for solar axions or axion-like particles, which are also candidates of the mysterious dark matter in the Universe. In addition, CAST has been converted the last few weeks to the first chameleon helioscope; chameleons or other particles with similar properties are candidates for the even more mysterious dark energy which acceler-ates the expansion of the Universe. CAST data has been used also by other groups to constraint the Hidden Sector of the Universe (”paraphotons”). In the report to CERN (see below) we propose [D. Hoffmann (TU-Darmstadt), A. Lindner (DESY) and K. Zioutas] on the possible conversion of CAST to a unique antenna for relics like axions from the Big Bang. Thus, CAST covers the entire field of the dark sector that dominates the Universe (~96% of its mass-energy budget). CAST undergoes annual evaluation by the CERN SPSCommittee (see the recent writ-ten report: CERN-SPSC-2013-027 / SPSC-SR-123 14/10/2013 (https://cds.cern.ch/re-cord/1610238).

Infrastructure – Facilities

Within the various axion activities, infrastructure and expertise from the Physics Depart-ment is being well utilized. In particular, nano-structures from the solid state section and image processing from the electronic section of the Department has found a well recog-nized contribution to CAST and the other ongoing collaborations.

Collaborations & Recent Projects

CAST is an international collaboration with 19 Institutes from Europe, USA and Canada.3 greek collaborating institutions provide groups for CAST: AUThessaloniki, NTUAthens and DEMOKRITOS. Astrophysical axion signatures: with Prof. V. Anastassopoulos from the Physics Depart-ment, Y.K. Semertzidis / BNL (spokesperson of the pEDM experiment in the FERMI-lab) and others we search / claim novel signatures for exotica like axions. More specifically:SPHINX / HINODE observatories in space; the ongoing collaboration consists of groups from the Physics Department (V. Anastassopoulos, K. Zioutas), DESY (A. Lindner, ALPS spokesperson), SPHINX (J. Sylwester, Principal Investigator) and SACLAY (T. Papaevan-gelou, permanent staff).


CERN COURIER articles 1) CAST’s first decade of solar-axion Research K. Zioutas, CERN Courier, 2010 2) The enigmatic Sun: a crucible for new physics

GROUP MEMBERS

Konstantin ZIOUTASProfessor (emer.) & CERN & Spokesperson of the CERN experiment CAST.

Collaborators:• A. Gardikiotis PhD-student in astropartile physics with CAST.• D. Anastassopoulos, A. Vradis, N. Spiliopoulos, A. Chtristoulaki (Post graduate) (nano-technology for CAST).• V. Anastassopoulos (Novel Signal and Image process-ing techniques for CAST and HINODE data).• A. Argiriou (Laboratory of Atmospheric Physics of the University of Patras).


K. Zioutas, CERN Courier, 2008

Review articles: Axion Searches with Helioscopes and astrophysical signatures for axion(-like) particles, K. Zioutas, M. Tsagri, Y. Semertzidis, T. Papaevangelou, T. Dafni, V. Anastassopoulos New J. Phys. 11 (2009) 105020; selected by N.J.P. as 1 out of 5 as “BEST OF 2009”.Searches for Astrophysical and Cosmological AxionsS.J. Asztalos, L.J. Rosenberg, K. van Bibber, P. Sikivie, K. ZioutasAnnu. Rev. Nucl. Part. Sci.56 (2006) 293

CAST publications:1) A Decommissioned LHC model magnet as an axion telescope. K. Zioutas, et al., Nucl. Instr. Meth. A425 (1999) 480.The CAST proposal.2) First results from CAST, K. Zioutas et al., (CAST collab.) Phys.Rev.Lett.94 (2005)121301, [hep-ex/0411033].3) CAST solar axion search with 3He buffer gas: Closing the hot dark matter gap M. Arik, …, K. Zioutas, arXiv:1307.1985 [hep-ex]. 4) The quest for axions and other new light particles K. Baker, …, K. Zioutas arXiv:1306.2841 [hep-ph]. Ann. Phys. 525 (2013) A93, 5) Detection of radiation pressure from solar chameleons,O.K. Baker, A. Lindner, Y.K. Semertzidis, A. Upadhye, K. Zioutas, arXiv:1201.6508 6) A chameleon helioscope O.K. Baker, A.Lindner, A. Upadhye, K. Zioutas, arX-iv:1201.0079 7) Fundamental Physics at the Intensity Frontier, J.L. Hewett, ..., K. Zioutas, arX-iv:1205.2671.

Astrophysical signatures:1) The 11-years solar cycle as the manifestation of the dark Universe,K. Zioutas, M. Tsagri, Y.K. Semertzidis, T. Papaevangelou, D.H.H. Hoffmann, V. Anastassopoulos, arXiv:1309.4021, Asked by editor to publish it in Mod. Phys. Lett. A.2) On the nature of dark matter in the Coma ClusterK. Zioutas, D.H.H. Hoffmann, K. Dennerl, T. Papaevangelou. arXiv:1307.3705 3) Flux Enhancement of Slow-moving Particles by Sun or Jupiter: Can they be Detect-ed on Earth?, B.R. Patla, R.J. Nemiroff, D.H.H. Hoffmann, K. Zioutas. arXiv:1305.2454, ApJ. (2014), in press. 4) Detection prospects for solar and terrestrial chameleons, P. Brax, A. Lindner, K. Zioutas. Phys. Rev. D85 (2012) 043014; [arXiv:1110.2583]. 5) Prospects for searching axionlike particle dark matter with dipole, toroidal, and wiggler magnets, O.K. Baker, M. Betz, F. Caspers, J. Jaeckel, A. Lindner, A. Ringwald, Y. Semertzidis, P. Sikivie, K. Zioutas. Phys. Rev. D 85, 035018 (2012) [arXiv:1110.2180] 6) The Mysterious sun: a source and a trap of exotica, K. Zioutas, M. Tsagri, Y. Se-mertzidis, T. Papaevangelou, E. Georgiopoulou, T. Dafni, V. Anastassopoulos. J. Phys. Conf. Ser. 309 (2011) 012021.7) Searching for decaying axion-like dark matter from clusters of galaxies, S. Riemer-Sorensen, K. Zioutas, S.H. Hansen, K. Pedersen, H. Dahle, A. Liolios. Phys. Rev. Lett. 99 (2007)131301, [astro-ph/0703342].

Other activityThe PATRAS WORKSHOPS on axions, WIMPS and WISPS. With Prof. V. Anastas-sopoulos we are in the international organizing committee of the workshops. http://axion-wimp2013.desy.de/

Additional information: see details in https://cds.cern.ch/record/1610238.

AXIONS(Dark Matter)CHAMELEONS (Dark Energy) “first”

AXIONS (Dark Matter)

CFD simulations


Particle Physics and Cosmology Research Group


Research Activities

The research focuses in the field of fundamental research in Elementary Particle Physics, which aims at the understanding of the structure of matter and the interactions between its fundamental entities. The currently established theory, the Standard Model of Particle Physics, despite its success, still leaves many open questions (among others, it cannot account for the existence of neutrino masses, as indicated by the data from several ex-periments). The recent discovery of the Higgs particle at the LHC (Large Hadron Collider), on the other hand, severely constrains possible new theories. In addition, the physics of elementary particles has very important links with cosmology, and the early universe can be seen as a giant accelerator where particle physics can be tested. Within this framework, our research is centered around three main axes:• A theoretical study of Standard Model extensions in association with the origin of mass, as indicated by the LHC Higgs mass predictions, the neutrino data, and several other experiments that provide important input on flavor violation.• A detailed analysis of the implications of such theories for searches for new particles and interactions in experiments, with particular emphasis at the LHC and a future Linear Collider.• An analysis of related cosmological topics, including the origin of dark matter, leptogen-esis/baryogenesis and phase transitions in the early universe.

Main International Collaborations

Long-standing collaborations, reflected in the publication list that follows, exist particularly with the following research institutes: CERN (European Center for Nuclear Research, CH), King’s College London (UK), Universities of Bergen and Oslo (NO) and University of Huelva (ES). There are also several participations in large-scale collaborations for future experi-ments, particularly a Linear Collider and a Neutrino Factory.

Major funded projects

1. European Marie Curie Excellence Grant, MEXT-CT-2004-014297 (2004-2009), “Standard Model Extensions with Massive Neutrinos: Phenomenology, Model Building and Cosmo-logical Implications”, hosted at the Department of Physics. University of Patras. 2. Member of the European Marie Curie Research Training Network UniverseNet, MRTN-CT-2006-035863 (2006-2010), “Origin of the Universe: Seeking links between fundamental physics & cosmology”.3. Member of the European Marie Curie Research Training Network HEPTOOLS, MRTN-CT-2006-035505 (2006-2010), “Tools and Precision Calculations for Physics Discoveries at Colliders”.4. Collaboration within the Spanish Research Project FPA-2009-10773 (2009-2011), “Phe-nomenology in Particle and Astroparticle Physics”.

GROUP MEMBERS

Smaragda LolaProfessorD. Phil (University of Oxford)[email protected]

CollaboratorsProf. John EllisCERN, Geneva and King’s College, London

Prof. Per OslandUniversity of Bergen

Prof. Are RaklevUniversity of Oslo

Prof. Mario GomezUniversity of Huelva


Recent Journal Publications

1. “Search for Tau Flavour Violation at the LHC”, E. Carquin, J. Ellis, M. Gomez, S. Lola, J. Rodriguez-Quintero, JHEP 0905 (2009) 026. 2. “Supersymmetric Grand Unification and Lepton Universality in K " l ν Decays”, J. Ellis, S. Lola, M. Raidal, Nucl.Phys. B812 (2009) 128. 3. “WMAP constraints on Dark Matter and Yukawa Unification with Massive Neutri-nos”, M. Gomez, S. Lola, P. Naranjo and J. Rodriguez-Quintero, JHEP 0904 (2009) 043. 4. “Gravitino Dark Matter and the Flavour Structure of R-violating Operators”, S.Lola, P. Osland, A. Raklev, Phys. Lett. B677 (2009) 62. 5. “Physics at a Future Neutrino Factory and Super-Beam Facility”, A. Bandyopadhyay et al., Rep. Prog. Phys. 72 (2009) 106201. 6. “Quintessential Kination and Thermal Production of Gravitinos and Axinos”, M. Gomez, S. Lola, C. Pallis, J. Rodriguez-Quintero, JCAP 0901 (2009) 027. 7. “Tracking Quintessence and Cold Dark Matter Candidates”, S. Lola, C. Pallis, E. Tzelati, JCAP 0911 (2009) 017. 8. “Suppression of Lepton Flavour Violation from Quantum Corrections above M GUT”, M.E. Gomez, S. Lola, P. Naranjo, J. Rodriguez-Quintero, JHEP 1006 (2010) 053.9. “Photon, Neutrino and Charged Particle Spectra from R-violating Gravitino Decays”, N.-E. Bomark, S. Lola, P. Osland, A.R. Raklev, Phys. Lett. B686 (2010) 152.10. “Gravitino dark matter and R-violating SUSY searches”, S. Lola, Fortschr. Phys. 59 (2011) 1093.11. “Searches for lepton flavour violation at a Linear Collider”, E. Carquin, J. Ellis, M.E. Gomez and S. Lola, JHEP 11 (2011) 050.12. “Flavour Structure of R-violating Neutralino Decays at the LHC”, N.E. Bomark, D.Choudhury, S. Lola and P. Osland, JHEP 1107 (2011) 070.13. “Neutrino textures and charged lepton flavour violation in light of θ13 , MEG and LHC data”, M. Cannoni, J. Ellis, M. E. Gomez, S. Lola, arXiv:1301.6002 [hep-ph] (2013), in press.14. “Long lived charginos in Natural SUSY?”, N. -E. Bomark, A. Kvellestad, S. Lola, P. Osland, A.R. Raklev, arXiv:1310.2788 [hep-ph] (2013), in press.

Exotic slow gravitino decays that can explain the observed extra-galactic gamma ray fluxes.

Contours for the discovery of lepton-flavour violation in slepton pair production in Linear Colliders, in the presence of massive neutrinos. Relevant experimental bounds and cosmological data from WMAP have also been included.


Research Profile of the Team Mechanics and Fluid Mechanics



The major aim of the team is the development of physical and mathematical models for the simulation of physical problems and their solution with the use of Numerical Methods. Over the last years our research is focused on the study of :• micropolar and nanofluids flows • magnetohydrodynamics and ferrohydrodynamics• biofluids flow in cardiovascular system and aims to the understanding of the physics aspects of the flow and, to the efficient solu-tion of the governing flow equations by developing robust, accurate and efficient numeri-cal methods and techniques.

Towards the goal of a deeper understanding of Physical Phenomena, the starting points are the principles of:

• Theoretical and computational fluid and solid mechanics • Biomechanics and biofluid-dynamics • Applied Mathematics and scientific computing • Transport phenomena • Energy and Mass Transfer

Tools are Theoretical and Computational Methods that, among others, include:

• Meshless Methods• Finite Element Methods • Boundary Element Methods • Spectral Element Methods • Finite Differences • Volume of Fluid Methods

Collaborations• Max Planck Institute, Germany.• King Abdullah University of Science and Technology (KAUST), Saudi Arabia.• École polytechnique fédérale de Lausanne (EPFL), Switzerland.• Institute of Chemical Engineering Sciences (ICE/HT), Greece.• School of Medicine, Department of Medical Physics, University of Patras, Greece.• Faculty of Medicine, National and Kapodistrian University of Athens, Greece.

Projects Running

Archimedes III, “Mathematical and computational study of the flow field of biological fluids for therapeutic design in clinically important conditions”. Budget: 90.000 Euro. Researcher. Starting/ending dates: 01/01/2012-31/12/2014.

GROUP MEMBERS

Vassilios C. LoukopoulosAssistant [email protected] T. KarahaliosRetired [email protected]

PhD Students:Mr. G.T. [email protected]

MSc Students:Mrs Freideriki [email protected] Mrs. Vali [email protected]


Selected recent publications:

1. G.C. Bourantas, E.D. Skouras, V.C. Loukopoulos and G.C. Nikiforidis, “An accurate, stable and efficient domain-type meshless method for the solution of MHD flow prob-lems”, Journal of Computational Physics, Vol. 228, pp. 8135-8160, (2009).2. G.C. Bourantas, E.D. Skouras, V.C. Loukopoulos and G.C. Nikiforidis, “Meshfree point collocation schemes for 2D steady state incompressible Navier-Stokes equa-tions in velocity-vorticity formulation for high values of Reynolds number”, Computer Modeling in Engineering & Sciences (CMES), Vol. 59, No. 1, pp. 31-64, 2010.3. G.C. Bourantas, E.D. Skouras, V.C. Loukopoulos and G.C. Nikiforidis, “Numeri-cal solution of non-isothermal fluid flows using local radial basis functions (LRBF) interpolation and a velocity-correction method”, Computer Modeling in Engineering & Sciences (CMES), Vol. 64, No. 2, pp. 187-212, 2010.4. V.C. Loukopoulos, G.C. Bourantas, E.D. Skouras and G.C. Nikiforidis, “Localized meshless point collocation (LMPC) method for time-dependent magnetohydrody-namics (MHD) flow through pipes under a variety of wall conductivity conditions”, Computational Mechanics, Vol. 47, No. 2, pp. 137-159, 2011.5. V.C. Loukopoulos and G.C. Bourantas “MLPG6 for the solution of incompressible flow equations”, Computer Modeling in Engineering & Sciences (CMES), Vol. 88 (6) pp. 531-558, 2012.6. G.C. Bourantas, E.D. Skouras, V.C. Loukopoulos and G.C. Nikiforidis, “Natural convection of nanofluids flow with “nanofluid-oriented” models of thermal conductiv-ity and dynamic viscosity in the presence of heat source”, International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 23, pp. 248-274, 2013.7. G.C. Bourantas, E.D. Skouras, V.C. Loukopoulos and V.N. Burganos, “Heat transfer and natural convection of nanofluids in porous media”, European Journal of Mechan-ics - B/Fluids, in print, 2013.8. V.C. Loukopoulos, G.T. Messaris, G.C. Bourantas, “Numerical Solution of the Incompressible Navier-Stokes Equations in Primitive Variables and Velocity-Vorticity Formulation”, Applied Mathematics and Computation, Vol. 222, pp. 575-588, 2013.9. G.C. Bourantas, V.C. Loukopoulos, “Modeling the natural convective flow of mi-cropolar nanofluids”, International Journal of Heat and Mass Transfer, Vol. 68, pp. 35-41, 2014.10. G.C. Bourantas, V.C. Loukopoulos, “A meshless scheme for incompressible fluid flow using a velocity-pressure correction method”, Computers and Fluids, Vol. 88, pp. 189-199, 2013.11. G.C Bourantas, E.D. Skouras, V.C. Loukopoulos, V.N. Burganos and G.C. Nikiforid-is, “Two-phase blood flow modeling and mass transport in the human aorta”, 10th International Workshop on Biomedical Engineering, 2011.

Validation of the proposed MINAM (micropolar nanofluid model) results with experimental results. Average Nusselt number over Ra number with increasing microro-tation and solid volume fraction equal to φ=0.1.

MLPG: Streamlines and isotherms concentric annulus between inner circular cylinder and outer square cylinder for Ra=106 and rr=0.25.

(a) Domain walls and (b) internal streamlines in a renal aortic and adjoin right (R) and left (L) arterial segment using turbulent SST description


Quantum and Classical Dynamical Systems and Quantum Information Research Group


Area of Research

Mathematical Physics

Topics:

1. Integralbility and Chaos in Classical and Quantum systems.Inter-relation of the corresponding properties in the classical and quantum regimes. 2. Quantum Information theory.Study of Entaglement and decoherence in relation to concrete properties of dynamical systems. 3. Information Geometry.- Use of Classical Information Geometry in Financial mathematics.- Flows in Information Geometry.- Quantum Information Geometry and the search for optimal Fisher metrics.4. Geometric Phases and properties of Dynamical systems.

Resent Publications

1 “A Curvature dependent bound for entanglement change in classically chaotic sys-tems”, Demetris P.K. Ghikas, George Stamatiou, International Journal of Quantum Infor-mation Vol. 5, No. 5 (2007) 685–704. 2. “Quantum entanglement dependence on bifurcations and scars in non-autonomous systems. The case of quantum kicked top”, George Stamatiou, Demetris P.K. Ghikas, Physics Letters A 368 (2007) 206–214. 3. “Stochastic anti-resonance in the time evolution of interacting qubits” Demetris P.K. Ghikas, Athanasios C. Tzemos, International Journal of Quantum Information 03/2012; 10(2). 4. “Dependence on state preparation of noise induced effects in multiqubit systems” A.C. Tzemos, D.P.K. Ghikas, Physics Letters A377 (2013) 2307-23165. “Classical and Quantum Chaos, Nonlinear Phenomena in Complex Systems”, 11, 141, (2008), Demetris P.K. Ghikas, Review Article.6. “A new information metric and a possible higher bound for a class of measure-ments in the Quantum Estimation Problem”, Demetris P.K. Ghikas, Fotios Oikonomou arXiv:1210.1977v1 [quant-ph]7. “Systems of qubits in chaotic and noisy environments. Possible effects of the local environments on the quantum coherence properties”Demetris P.K. Ghikas, Athanasios C. Tzemos, George Stamatiou , Poster in Conference “Noise, Information and Complexity @ Quantum Scale” held in Erice, Italy, 6-12 Oct 2013.

Invited Talks

1. Dynamics and Information Geometry, First Mediterranean Conference on Nonlinear Dynamics and its Applications July 3-8, 2008 - Pescara, Italy

GROUP MEMBERS

Demetris P.K. GhikasProfessor [email protected]

G. StamatiouPh.D.A. KavvadiaDoctorate StudentP. EconomouDoctorate StudentA. TzemosPh.D.

CollaborationAngela de SanctisAssociate ProfessorUniversity of Pescara


2. Information Geometry and Quantum Dynamical Systems: Conceptual Problems and Potential Applications,GR-TR Conference on Statistical Mechanics and Dynamical Systems September 11-17/2008 Rodos-Mamaris

Appearance of Stochastic and Anti-Stochastic resonance depends on the preparation.


Computational Astrophysics Research Group


Research Activities

• Numerical methods and techniques for the computation of models of white dwarfs and neutron stars with rotation and magnetic fields.

• Computation of gravitational waves emitted by rotating magnetic and/or oscillating neutron stars.

• Computation of models of the solar planetary system and of the systems of satellites of large planets (like the Jupiter’s system of satellites).

• Computation of cosmological models obeying specific pregeometries.

• Development of codes for solving initial value problems of complex-valued functions in one complex variable along complex paths.

• Development of codes for counting and computing eigenvalues of complex tridiagonal matrices and roots of complex polynomials, lying in given regions of the complex plane.

• Parallel codes for solving initial value problems in the complex plane.

• Parallel codes for computing eigenvalues of complex tridiagonal matrices and roots of complex polynomials.

Representative Recent Publications

• Papasotiriou, P.J., Geroyannis, V.S., & Sanidas, S.A..: 2007, Numerical methods for solv-ing the relativistic Oppenheimer-Volkoff equations, IJMPC (Computational Physics) 18, 1735-1746.

• Geroyannis, V.S., & Katelouzos, A.G.: 2008, Numerical treatment of Hartle’s perturbation method for differentially rotating neutron stars simulated by general-relativistic polytropic models, IJMPC (Computational Physics) 19, 1863-1908.

• Geroyannis, V.S., & Sfaelos, I.E.: 2011, Numerical treatment of rotating neutron stars simulated by general-relativistic polytropic models: a complex-plane strategy, IJMPC (Computational Physics) 22, 219-248.

• Geroyannis, V.S., Katelouzos, A.G., & Valvi, F.N.: 2011, Magnetized rotating neutron stars simulated by general-relativistic polytropic models: the numerical treatment, IJMPC (Computational Physics) 22, 1107-1137.

• Geroyannis, V.S., & Valvi, F.N.: 2012, A Runge-Kutta-Fehlberg code for the complex plane: comparing with similar codes by applying to polytropic models, IJMPC (Computa-

GROUP MEMBERS

V. S. [email protected]

PhD Researchers - Col-laborators:Dr. T. G. [email protected]. A. G. [email protected]. I. E. [email protected]

PhD Students:Mr. V. G. Karageorgopoulos, MSc, [email protected]. E. E. Tzelati, MSc, [email protected]

MSc Students:Mr. I. [email protected]. A. [email protected]


tional Physics) 23, 1250038(1-15).

• Valvi, F.N., & Geroyannis, V.S.: 2012, Explicit inversion for two Brownian-type matri-ces, Applied Mathematics 2012, 3, 1068-1073.

• Sfaelos, I., & Geroyannis, V.: 2012, Third-order corrections and mass-shedding limit of rotating neutron stars computed by a complex-plane strategy, International Jour-nal of Astronomy and Astrophysics 2012, 2, 210-217.

• Valvi, F.N., & Geroyannis, V.S.: 2013, Counting and computing the eigenvalues of a complex tridiagonal matrix, lying in a given region of the complex plane, IJMPC (Com-putational Physics) 24, 1350008(1-10).

• Geroyannis, V., & Valvi, F.: 2013, Parallelizing a code for counting and computing ei-genvalues of complex tridiagonal matrices and roots of complex polynomials, Applied Mathematics 2013, 4, 797-802.

• Katelouzos, A., & Geroyannis, V.: 2013, Computing differentially rotating neutron stars obeying realistic equations of state by using Hartle’s perturbation method, Inter-national Journal of Astronomy and Astrophysics 2013,3, 217-226.

• Geroyannis, V.S., & Karageorgopoulos, V.G.: 2014, Computing rotating polytropic models in the post-Newtonian approximation: the problem revisited, New Astrono-my, 28, 9-16.

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