Victor Claerbout, a Ph.D. student of the doctoral study program Applied Physics at FEE CTU, successfully defended his thesis “Solid lubricants at the nanoscale: frictional behavior in silico” at the end of June, becoming the first graduate of this new study programme. The supervisor was Dr. Paolo Nicolini. The opponents were Prof. Dr. Enrico Gnecco from Friedrich-Schiller Universitaet Jena, Prof. Dr. Daniele Dini from Imperial College London and Dr. Ondrej Hovorka from the University of Southampton. The thesis is nominated for the Dean’s Award. The student conducted his research within the Advanced Materials Group research team from the Department of Control Engineering. Congratulations to the graduate for a successful defense!
Jul 22 2021
The article by David Rutherford et al. about “Growth Inhibition of Gram-Positive and Gram-Negative Bacteria by Zinc Oxide Hedgehog Particles” has been published in May in the International Journal of Nanomedicine – an international peer-reviewed journal focusing on the application of nanotechnology in diagnostics, therapeutics, and drug delivery systems throughout the biomedical field. The article reached more than 1400 views in 4 weeks since the publication in May and David Rutherford has been awarded „Favored author“ status.
Interest in nanoparticles for antibacterial applications has been increasing significantly over the last 10 years due an alarming rise in bacteria that are resistant to common antibiotics as well as due to a lack of new pharmaceutical research in this area. Zinc oxide represent one example of such inorganic materials which exhibit considerable antibacterial effect. It is assumed to act via reactive oxygen species (ROS) generation and zinc ion production, both of which can be toxic in high concentrations, as well as via surface interactions between the nanoparticles and bacteria. In our research, we investigated what role particle size, shape, and concentration have on the antibacterial effect by using novel zinc oxide microstructures, called “hedgehogs”, and comparing them with two commercially available ZnO nano- and micro-particles. The hedgehog ZnO particles proved to be more effective due to their specific microstructure, even in biological media that suppress other antibacterial pathways. They could be thus a viable alternative for water treatment and surface decontamination applications where the presence of bacteria poses a serious risk to human health.
The research has been lead by the Department of Physics FEL CTU, where the microbiological and nanomaterial experiments were carried out. The hedgehog ZnO particles were synthesized at the Institute of Chemistry, Slovak Academy of Sciences, and the materials were characterized with assistance from colleagues at the Institute of Physics, Czech Academy of Sciences, and at the Faculty of Mathematics and Physics, Charles University.
This research was conducted within the international GACR project with National Pingtung University, Taiwan. It was supported also by the Centre of Advanced Applied Sciences (CAAS) at CTU, Slovak Scientific Grant Agency (VEGA), and it made use of the CzechNanoLab Research Infrastructure.
Jun 22 2021
The article “Mapping of azimuthal B-fields in Z-pinch plasmas using Z-pinch-driven ion deflectometry“ has been published in the scientific journal Physics of Plasmas, the largest journal dedicated to the field of experimental and theoretical plasma physics published by the American Institute of Physics (AIP). The article has shortly become the most-read article and was not only selected as the “Editor’s Pick” but also on the cover page of the June edition. The first author is Ing. Vojtěch Munzar, a Ph.D. student in prof. Daniel Klír’s group at the Department of Physics, FEE CTU.
The ion deflectometry is a diagnostic method for electric and magnetic field measurements in hot dense plasmas, which is otherwise difficult to access by conventional methods. High-energy ions do not scatter by the plasma; their trajectories are only deflected in these fields by the Lorentz force. A shadow of the fiducial grid, imprinted in the ion beams, deforms due to deflections of the ion trajectories. The grid distortions reveal a 2D distribution of the studied fields. The proton deflectometry has been widely used in laser-produced plasmas, but its use for analyzing the plasma of a Z-pinch (a plasma fiber) has been cumbersome. In collaboration with colleagues at the GIT-12 device in Tomsk, our research group at the Department of Physics developed an original way to accelerate the ions from within the Z-pinch itself without any laser system. It allowed us to reach the hot center of the plasma fiber with temperatures of a few million degrees Celsius and to study the profile of magnetic fields that dominantly influence the Z-pinch dynamics. As a result, we understand better the Z-pinch phenomenon that appears in many fields of physics including solar protuberances and formation of nebulae.
The research has been supported by the Czech Science Foundation, Ministry of Education, Youth, and Sports of the Czech Republic, and CTU.
Mar 30 2021
The cover page of Physica status solidi has been for many years presenting the international scientific community with high-quality research in the field of materials science and solid state physics. Properties and functions of various ZnO materials are intensively investigated in biological systems for diagnostics, therapy, health risks assessment as well as bactericidal and decontamination purposes. In our work, the interface between ZnO and biological environment was studied by characterizing adsorption of bovine serum albumin (BSA) and fetal bovine serum (FBS) using atomic force microscopy with CF4‐treated tips. Similar molecular morphologies (thickness around 2 nm) yet different binding forces to ZnO (10 – 25 nN) were observed. These observations are corroborated by atomic scale simulations of BSA on (0001) ZnO surface using a force‐field method and showing rearrangements of zinc surface atoms. Such binding may have an impact also on other properties of ZnO–BSA complex. The work has been done jointly by the teams from the Czech Technical University in Prague and the Institute of Physics of the Czech Academy of Sciences within the international GACR-MOST project with the National Pingtung University in Taiwan.
Mar 19 2021
The Dean of the Faculty of Electrical Engineering CTU Prof. Mgr. Petr Páta, Ph.D. awarded the Dean’s Award for a prestigious dissertation thesis to Dr. Jan Fait on March 10. The topic of the dissertation is Fabrication and characterization of diamond photonic structures. The supervisor was Prof. Bohuslav Rezek from the Department of Physics and supervisor specialist Dr. Lukáš Ondič from the Institute of Physics of the Czech Academy of Sciences. The research was conducted in a close cooperation between the Czech Technical University in Prague and the Institute of Physics.
Jan Fait studies photonic structures that serve to achieve maximal detection efficiency of photons emitted by color centers in diamond. These centers have a number of interesting features that find use in quantum communication, sensorics or biomedicine. Maximized detection of photons is crucial for these applications. Jan Fait focuses both on the optimization of photonic structures and on new methods of their fabrication using a thin layer of amorphous silicon. The results of the work were published in scientific journals with significant number of citations and presented at international conferences. The dissertation is available for view on Dspace ČVUT.
Mar 19 2021
An integral part of our Physics course are the experiments demonstrated in the lab. Our very modern lab offers a vast selection of experiments that the students can conduct first-hand, under normal circumstances. Due to Covid-19 restrictions the learning moved to an online space, so we are trying to introduce experiments to our students in other ways.
We have created multimedia presentations of the lectures containing the actual demonstration of the experiment with the teacher’s commentary. One of the experiments covered in the course Physics 1 is a study of “Free Fall“. The experiment is elegantly simple: by measuring the duration of the fall of a steel ball from varying heights, we can determine the acceleration due to gravity in Prague (more specifically, in our 4th floor lab in Dejvice). Moreover, this experiment is also helpful for understanding how gravity and other forces affect an object in motion, both here on Earth and in the outer space. The instructions for the experiments are available to students on Moodle.
May 11 2020
Our work on the “Bio-chemically selective interaction of hydrogenated and oxidized ultra-small nanodiamonds with proteins and cells” has been recently published in Carbon [Machova et al., Carbon 162 (2020) 650-661, doi:10.1016/j.carbon.2020.02.061] and selected for the journal front cover page (pdf). Ultra-small nanoparticles of a size smaller than or comparable to cell membrane pores (1-5 nm) have significant potential in biomedicine. In our study, we performed a systematic in vitro investigation of fundamental bio-chemical interactions of such ultra-small hydrogenated and oxidized detonation nanodiamonds (DNDs) with biomolecules and human cells. We applied mass spectrometry methods (LC-MS/MS) for the qualitative and quantitative analysis of the protein corona as a function of the surface chemistry and size of DNDs. We observed that protein interactions with DNDs are more related to their surface chemistry (H/O-termination) rather than size. Bioinformatics characterization of the identified proteins pointed to the strong influence of electrostatic interaction between proteins and DNDs depending on their surface termination. Such specific interaction lead to formation of different protein corona on hydrogenated or oxidized 2 nm DNDs, which influenced also their interaction with cells including different level of cytotoxicity. The work has been done jointly by the teams from Charles University in Prague, Czech Academy of Sciences and Czech Technical University in Prague.
Jan 29 2020
The Journal of Applied Physics highly appreciated a research work “DC-driven atmospheric pressure pulsed discharge with volume-distributed filaments in a coaxial electrode system” carried out by employees of the Department of Physics, FEE CTU. The Editorial Office of the Journal of Applied Physics selected the work as the lead cover article in the eighth issue, vol. 126, 2019 of the Journal (https://doi.org/10.1063/1.5113950).
Reproduced from the Journal of Applied Physics 126(8), 28 August 2019, with the permission of AIP Publishing.
Nov 21 2017
The VZLUSAT-1 nanosatellite was developed on the basis of a standardized CubeSat 2U platform (20x10x10cm) in the Czech Aerospace Research Centre (VZLU) in cooperation with Czech companies and universities.
Nanosatellite VZLUSAT-1 in laboratory
Ing. Ladislav Sieger from Department of Physics led the successfully defended master’s thesis of Ing. Veronika Stehlíková, Ing. Martin Urban and Ing. Ondřej Nentvich from the Department of Radio Electronics. They engaged in the development, construction and testing of the satellite together with Ing. Tomáš Báka.
On June 23, 2017, the two-kilogram Czech nanosatellite VZLUSAT-1 was transported to the Earth’s orbit using the PSLV-C38 rocket launched from Indian space spaceport at Sri Charikota Island.
Jun 21 2017
PhD student Petra Matunová from Institute of Physics CAS and Department of Physics at CTU FEL presented a poster entitled “Computing interfacial properties of polypyrrole on diamond nanoparticles for photovoltaic applications” at the International Workshop on Computational Nanotechnology (IWCN 2017, Windermere, UK). This poster was announced by the organizers as one of the five best student posters of the conference.