Over the past 40 years, the Standard Model (SM) of elementary particles and their interactions has been providing an unfailing and remarkably accurate description of all experiments with and without high-energy accelerators. With the discovery of the Higgs boson at the Large Hadron Collider in 2012, the SM is now complete, and we believe that we understand the physics of the very small up to...
The last few years have seen a remarkable development in our ability to control many neutral atoms individually, and induce controlled interactions between them on demand. This progress ushers in a new era where one can create highly entangled states, or study quantum phase transitions. I will present results on atomic arrays containing more than 250 atoms, including transport of entangled...
The modern market requires new multifunctional materials which should be compatible with both electronics and living organisms. In this presentation, we report on novel bio-inspired hybrid nanomaterials – the so called aero-materials based on semiconductor compounds [1-4]. In particular, we report on a novel bio-inspired 3D nanoarchitecture of GaN, called aero-GaN or Aerogalnite, which...
The Macedonian educational system is under continuous reforms and changes made to the syllabuses and methods of teaching. In the last two decades, almost every aspect of teaching mathematics and physics in primary school has been changed. The last three major changes cover different approaches: coordinated teaching in 2008, curriculum changes towards research methods and problem solving in...
Transmission lines are traditionally modelled by considering Heaviside’s elementary circuit that contains a resistor and inductor in the series branch, accounting for the energy losses and magnetic effects, while the shunt branch contains a resistor and a capacitor, accounting for the energy losses and capacitive phenomena. Classical telegrapher’s equations, modelling the signal propagation in...
Metal-coated microsphere arrays (MCMA), consisting of metal films deposited over dielectric (polymer, $SiO_2$) colloidal microspheres, represent a class of plasmonic crystals with proven capabilities as substrates for surface enhanced optical spectroscopy (Surface Enhanced Raman Scattering - SERS, Surface/Metal-Enhanced Fluorescence - SEF/MEF) or sensing based on Localized Surface Plasmon...
Thermal waves generated by the periodic fluctuations on time of a temperature field are widely used to determine thermal properties of macro-, micro-, and nanomaterials via standard photothermal techniques (thermoreflectance, radiometry, 3w, photoacoustics, and resonant cavity), and they usually do not carry a net heat flux in materials with constant thermal properties. By contrast, in...
The Markovian time evolution of the entropy production rate is studied as a measure of irreversibility generated in a bipartite quantum system consisting of two coupled bosonic modes immersed in a common thermal environment. The dynamics of the system is described in the framework of the formalism of the theory of open quantum systems based on completely positive quantum dynamical semigroups,...
Transition metal dichalcogenides, as a well studied family of quasi-2D materials, have attracted considerable attention in recent years due to rich phase diagrams, thickness-dependent transport, unique optical properties and collective electron phenomena which occur at experimentally accessible temperatures. Additionally, it was recently shown that in the metallic single crystal alloys of...
In the present work, we investigate the possibility to improve the students' understanding of the spectral properties of different light sources and the transmission/absorption of different media by means of a partially computer-based school experiment in physics. Numerous studies have identified certain difficulties in understanding and applying atomic models [1,2], and more specifically,...
Zinc selenide is a wide bandgap semiconductor which is attractive for the fabrication of many optoelectronic devices, including ultraviolet (UV) photodetectors, due to its large bandgap energy (2.67 eV at 300 K), high electric breakdown field strength (~ 1 MV/cm), as well as high resistance to intense UV and X-ray radiation. Most commercial UV-photodetectors are based on Si or GaAs...
Starting from a general completely integrable ‘diagonal’ equation in two dimensions and performing periodic reduction one can obtain coupled completely integrable equations. The idea is to consider that the independent discrete variable of the analyzed equation is in fact a diagonal in a two-dimensional (or d-dimensional) lattice. Imposing periodic reduction on the one such coordinate in that...
This article summarizes some of the features of pure indium antimonide nanostructures growth through TVA method and their potential applications in the industry. To obtain the expression of geometric magnetoresistance at low magnetic fields and the expression for resistance in intermediate magnetic fields, the current density equation was examined. For the particular case of the sandwich...
Students are learning and using graphs in compulsory education in Republic of Serbia within physics and mathematics. Nevertheless, students have difficulties in using kinematics graphs and their misinterpretation is often [1]. Students’ difficulties with graphs in physics are not necessary caused with the unsatisfying level of knowledge of graphs in mathematics [2]. Integration of physics is...
One of the processes that is assumed to be well understood, is that any fundamental Gaussian light beam experiences an axial phase shift of $π$ radians with respect of a reference plane wave when passing through its focus. For a higher-order Hermite-Gaussian mode with mode indices ($m,n$) this phase is multiplied by a factor of ($1+m+n$). For a higher-order Laguerre-Gaussian mode with mode...
Inflow of young learned community into the field of pure physics research has been declined throughout the world including Romania. The initial attitude and the understanding of the nature of scientific endeavors and the people associated with them have a great role in determining the choice of engineering as career. How children perceive the engineers can indicate how they perceive the nature...
Zink ferrite powders are widely studied due to their application in many fields, such as anode materials for lithium-ion batteries, gas sensors, magnetic materials, catalytic materials, and antibacterial materials in water treatment. We present the structural and magnetic properties of nanosized $ ZnFe_{2} $O$ _{4} $ powders synthesized by sonochemistry and discuss their dependence on the...
Shape and size are the basic characteristics of macroscopic, classical systems, and as such represent a special challenge within the fundamental problem of "transition from quantum to classical", but also the problem of quantum measurement. Propeller-shaped molecules are excellent candidates for analyzing the effects of size and shape because of the linear dependence of both the moment of...
The Enskog-Vlasov equation has proven successful in investigating fluids undergoing a phase change [1,2,3,4]. However, the numerical solution of this kinetic model is computationally demanding and, therefore, existing studies are restricted to one-dimensional planar flows or flows with cylindrical symmetry. In this work, a weighted particle scheme is developed for solving the Enskog–Vlasov...
Electromagnetism is considered one of the most complex topics of physics. Students face significant difficulties trying to get familiar with magnetic and electric phenomena. If the laws of electricity and magnetism and their theories are unclear to students, these phenomena become even more challenging to understand. In these situations, students usually start memorizing concepts without...
This study aims on the analysis of the pollens’ phenological distributions in the greater area of Thessaloniki, over the years 2016-2020. The main pollen season of the most contributable taxa of pollen spectrum is presented and its beginning, end and duration are compared with similar European studies. Regularity tests and probability plots revealed the absence of trend in timeseries....
Random field Ising model, in particular its nonequilibrium version, has been extensively used for modeling the behavior of disordered ferromagnetic materials driven by external magnetic field. To this point, for systems of finite size, two domains of disorder were identified based on the occurrence of spanning avalanches in the system.
Here we present new results clearly demonstrating the...
The Standard Model of particle physics is a remarkably successful and self-consistent theory of the microscopic universe. Nevertheless, profound contradictions between this microscopic world of the Standard Model and astrophysical and cosmological theories describing the macroscopic universe point to a need for a more complete theory. While we have so far failed to directly observe any...
The paper starts with a brief discussion of research studies investigating students’ misconceptions related to physics concepts, ideas and laws1. Then, we discuss the rich information on undergraduate students’ understanding when research focuses on investigating students’ reasoning in various areas of physics2, 3. The main body of the paper reports on recent research on undergaduate physics...
Recent advances in social sciences are based on extensive data analysis. In this context, theoretical physics concepts such as self-organized criticality are precious to making sense of the available empirical data. Self-organized criticality refers to the properties of driven dynamical systems of many interacting elements under repeated perturbations to reach a stationary state with...
Mineral dust is the most abundant aerosol, with the largest contribution to global aerosol mass load and significant aerosol optical depth [1]. Dust affects the Earth's radiative balance directly, through interaction with solar and terrestrial radiation, and indirectly, altering the optical properties and lifetime of clouds. There are still uncertainties in model estimates of dust radiative...
The electromagnetic field behavior is described by the set of Maxwell equations relating the electric and magnetic fields, charge density and current density. The electric and magnetic fields E and B can be written in terms of scalar and vector potentials.
Faraday’s law of induction is fundamental to understanding how electric and magnetic fields interact. Time-varying magnetic field give...
Ising model on honeycomb, decorated honeycomb and diced lattices, and other planar lattices with single decoration on each bond, is solved exactly in the presence of pair and triplet interactions with additional external magnetic field acting on specific sites. Field induced transition is observed when triplet interactions are present. Reentrance phenomenon is found in the decorated...
Rare B meson decays provide important input for studies of anomalies in $b \to s l^+l^-$ transitions. The $B^{0}_s \to \mu^+\mu^-$ is an example of a process with theoretically clean predictions and a clear experimental signature making it a perfect match for BSM physics searches. Here we present a measurement of $B^{0}_s \to \mu^+\mu^-$ branching fraction and effective lifetime in...
Complex systems display the structural organization of patterns that span over various inherent scales and accordingly affect the functioning of the system. Transcending pairwise interactions in complex networks introduces the study of higher-order structures [Battiston, F., et al. (2020), Physics Reports 874, pp. 1-92.], where the versatility of criteria for aggregation of elements imposes...
Polyaniline powders are prepared using two different reaction routes in order to obtain different morphologies. Using ammonium persulfate (APS) as a dopant and in a solution of ethanol and acetic acid, the polymerisation of aniline gave rise to tubular like nanostructures, thus the sample was named PANI-T. Similarly, PANI-R (polyaniline with a “round” morphology of nanostructures), was...
"Tell me and I will forget; show me and I will remember; include me and I will understand."
This report presents lessons conducted in regular Sience, Physics, and Astronomy classes related to a content area of expertise related to natural sunlight. Interdisciplinarity is presented through STEAM - based learning approaches and methods: exploratory approach, experiential learning, learning by...
Although the observed 125 GeV boson is so far compatible with the SM Higgs boson, non-SM properties cannot be ruled out. Assuming particle DM, invisible Higgs decays can be realized in models having interactions between the Higgs boson and dark matter, as for example, "Higgs-portal" models. This talk summarizes recent results from the CMS collaboration on invisible Higgs decays and outlines...
Abstract. Electric circuits are an important element of physics class. However, many students leave secondary school without having an adequate conceptual understanding of simple circuits. Voltage in particular is a difficult concept since students understand voltage as a property of the electric current. Gymnasium students in Montenegro did test which contained problems of understanding...
Ionic liquids (ILs) are two-component systems composed of large asymmetric and irregularly shaped organic cations and anions. Physical properties of ILs like negligible vapour pressure, high-temperature stability, high ionic conductivity and also a great variety of ILs and their mixtures highlight them as potentially relevant to lubrication [1, 2]. A large number of variations in IL...
Knowledge-sharing communities are fundamental for the development and evolution of any knowledge-based society. Their emergence, function, and disappearance determine the course of evolution of a knowledge-based society. The sustainability of these groups is crucial for the success of the knowledge-transfer process in modern societies and the efficiency and success of this process. This work...
The study of the associated production of vector bosons and jets constitutes an excellent environment to check numerous QCD predictions. Total and differential cross sections of vector bosons produced in association with jets have been studied in pp collisions using CMS data. Differential distributions as a function of a broad range of kinematical observables are measured and compared with...
Over the last two decades, it has been demonstrated that electrochemistry is one of the most accessible and cost-effective approaches for nanostructuring semiconductor materials in a controlled fashion. Moreover, taking into account that electrochemical nanostructuring in NaCl-based neutral electrolyte of semiconductor compounds such as InP, GaAs, and GaN was demonstrated, we succeeded to make...
Using TVA technology, multilayer and composite C-Ti layers were deposited on silicon substrates. The C-Ti multilayers were constructed from the silicon substrate as follows: 100nm of carbon, followed by alternant 17nm Ti and 40 nm C three times, covered by one last 17 nm Ti layer, resulting a seven multilayer structure. For the composite layer, after the pre 100nm carbon one, we varied quasi...
Founded in 1985, the Balkan Physical Union (BPU) strives to actively promote Physics, science, education, and cooperation between the Balkan countries. In accordance with these aims, as well as the goals of the Balkan Physics Olympiad, the BPU Council which was held in Sofia, in 2018, agreed that it should organize the First Balkan Physics Olympiad, which would function as a platform where the...
Recent results on inclusive W and Z boson productions obtained with CMS proton collision data at 13 TeV are presented. Results include total cross sections and decay properties of W and Z bosons. Recent differential results on Drell-Yan dilepton productions in a wide range of invariant masses are also included.
At the LHC, the absolute accuracy of the luminosity scale and its precision can be a limiting factor in terms of systematic uncertainty for some measurements such as that of the total proton-proton scattering cross-section. This report presents the calibration of the ATLAS luminometers by the van der Meer method in pp collisions at $\sqrt{s}~=~$900 GeV, during dedicated data-taking periods in...
The physicochemical properties of chocolate mass with 85% cocoa content and respectively content of 3%, 5%, and 10% of freshwater algae Spirulina Platensis have been studied. The algae are grown into a bioreactor in Varvara, Bulgaria. The present work aims to create an innovative chocolate product with appropriate physicochemical properties and organoleptic characteristics, contributing to the...
A phenomenological lagrangian is proposed to include dark sector mesons interacting through tensor currents with Standard Model leptons. For certain values of the interaction constant, the model has the potential of providing an explanation for the discrepancy between theory and experiment, regarding the anomalous magnetic moment of the muon, the Be-8 anomaly, and others, manifesting lepton...
Lattice Quantum Chromodynamics (LQCD) is the lattice discretization of QCD theory, the mathematically formulation that describes the strong interactions between elementary particles. It is based on complex numerical algorithms that comes from a similarity one by one among the path integral in statistical mechanics and the Markov chain in the Monte Carlo algorithm. Solving QCD theory with Monte...
The field of Nanoscience and Engineering (NSE) is a modern and dominant field of research that is developing rapidly, already offering useful products and applications. Nanoscience is the scientific branch that concerns the research of interactions at the nanoscale (1-100nm) while nanotechnology deals with the management and reconstruction of matter at the nanoscale. The development of NSE...
Studies of the global distribution of lightning show that the annual number of lightning over land is higher than over the sea. However some research reveals that lightning activity is different over various geographical locations and highly variable on timescales (annual, seasonal, monthly and daily). It is of interest to analyze the spatial and temporal distribution of lightning for specific...
The phenomena of electronic emission, in general, and thermoelectronic emission, in particular, seems that have already been studied well enough and there is nothing left to do. The electron beam, as a tool in the processing of materials is very convenient, because it does not cause changes in chemical composition and ensures processing in micrometric and nanometric scales.
It is...
In anticipation of JWST data, today’s study of early Universe galaxies focuses on preparations for efficient data handling. For that reason, in our previous work (Burgarella et al. 2021, in press), we constructed an IR template which is based mainly on the ALPINE data sample with an addition of a few other well-studied galaxies, which includes galaxies in the redshift range 4.5 $<$ z $<$ 6.2....
Flat-band (FB) photonic lattices are attracting substantial attention of researchers since they provide an excellent platform for studying various fundamental physical phenomena difficult to achieve in the condensed matter systems. In that regard, some of those phenomena demonstrated in the last two decade are discrete solitons, dynamical localization and Anderson localization in disordered...
The dynamic of the information distribution is complex and affects everyday life, especially with the multiple ideas that are being released in social networks. These multiple ideas often have competing nature for the same nodes of the network. In this work we will discuss two competitive influence diffusion models in social networks. First, we take in consideration the competitive cascade...
Group velocity control of light is of fundamental as well as practical interest for the construction of various optical devices such as optical buffers and quantum memories. In recent decades, great attention has been paid to the study of conditions and techniques for obtaining subluminal and superluninal light. It is found that the presence of Kerr nonlinearity can be usefull tool for group...
Determination of the maximal expected magnitude (Mmax) of future earthquakes is one of the most important part of seismic hazard and risk assessment. In this research, an attempt for determining the Mmax of the three neotectonic zones in North Macedonia was made, based on available seismological data for last 42 years. Two approaches were used: first one determining Mmax using the...
The aim of the present study is the description of the implementation and operation of an integrated modeling system that focuses on the Urban Heat Island and its impact on human health. The modeling system, used for both short-term prediction and future projection, was developed on two levels:
a. The UHI forecasting system which produces high-resolution (250 m) UHI-related products,...
The present study focuses on the description of a versatile and flexible air quality monitoring and forecasting system. The system provides environmental information and advice to stakeholders and citizens via proper hardware & software infrastructure, scientific expertise and computational excellence. It is a combination of three-dimensional air quality models (WRF/CAMx), innovative models...
The energy that comes from the source of ionizing radiation is enormous and quite unused. Using energy from ionizing radiation is a novel concept, while so far in the literature (to the best of our knowledge), only beta radiation has been treated as a possible source of energy (Quenon 2021). This paper focuses on utilizing gamma radiation energy using the Cobalt-60 radiation source. Direct...
The problem of pollution in Serbia is severe. In winter, concentrations of PM2.5 and PM10 often exceed the permitted values. In addition to official automatic stations for measuring air quality, it is useful to have low-cost sensors that are available to everyone. The benefit of this type of measurement lies in the fact that in addition to understanding the overall problem of pollution,...
Introduction. Trying to find out what should be understood by ‘climate’, the inquisitive reader is surprised by the lack of sufficient clarity about the content of this concept even today, although the term was used in antiquity and literally translated from Greek means "slope" (of the Sun's rays relative to the Earth's surface). The purpose of the study is to trace the formation of the...
Flatband (FB) photonic systems have been in the spotlight of researchers since they represent an advantageous testbed for studying transport and localization properties at the linear level [1]. Among variety of platforms where flatbands have been realized photonic lattices have been established as the ideal ones, since working with them is very comfortable - they are easy to manipulate with...
Coherent beam combining (CBC) is denoting a group of methods developed for achieving higher power/energy and for enhancing the spectral brightness of laser emission at preserved beam quality by combining several high-power laser beams (or sub-beams) [1]. On the other hand, the spectral broadening of coherent optical pulses is inevitably necessary for their compression in time. The beam...
Technology has the potential to dramatically improve our everyday life aspects, including the time we spend in the educational environments. If we want to add the teaching means and methods, then one of the solutions would be to include the smartphones in it.
The purpose of this paperwork is their use as an experimental tool to aid the students who study physics in a way that their concepts...
The term climate change refers to the change in the global climate and to changes in meteorological conditions that extend over a large scale of time. Such changes include statistically significant fluctuations in the average state of the climate or its variability, extending over a period of decades or even more years. Climate change is due to natural processes, as well as human activities...
Here we study the flux densities at 1380, 4908 and 15365 MHz, as well as the radio spectral index distribution of 3C 84, a Double Radio source Associated with Galactic Nucleus (DRAGN). 3C 84 is the dominant giant elliptical galaxy in the Perseus cluster, and thus very interesting for our research. This famous radio galaxy Perseus A has Relaxed Double classification because it has the large...
Τhere is a strong demand for new energy sources due to the growing population and limited natural resources. Among the different renewable energy resources, thermoelectric material plays a key role. Selenides compounds, such as Ag2Se and Cu2Se, have received a lot of attention because of their interesting properties, low toxicity, and abundance. Particurarlly, Ag, Cu, and Se are less toxic...
Nature has developed materials, objects and procedures that occur in the macro-scale as well as the nanoscale. The results of millions of years of biological evolution and the optimized “techniques” developed by the organisms are available to scientists who seek new ideas by studying the solutions provided by nature. The scientific field that allows man to imitate nature and to develop...
Discrete Time Quantum Random Walk Search (DTQRWS) is quantum search algorithm that is quadratically faster than its classical counterpart. It can be used to search on graphs with arbitrary topology. Some structures, like Hypercube offer potential for practical applications. This quantum algorithm is very sensitive to the precision of constructing the operators of both mark and traversing...
A numerical 0D global model is developed with an aim to study the influence of air and water vapour impurities on electron energy distribution function and chemical composition of atmospheric pressure helium plasma, focusing on the main reactive oxygen and nitrogen species. Model includes 1488 reactions among 74 species, taken from the literature [1,2]. Rate coefficients for electron impact...
Often in physics classes we are faced with the need for demonstration attempts. Some physics classes can be well organized using certain educational content from the numerical assignments and experimental assignments given at the International Physics Olympiads. As mentors of students and participants in the Olympics, we want to share some experiences from using texts, draft schemes or whole...
Over the last 20 years more inventions have emerged from NanoScience and Engineering (NSE) than any other scientific field (1). By 2030, its implications in regards to science, technology innovation, economy and society are expected to overcome even the ones from the digital revolution. Scientific research and development of technological applications in the nanoscale has provided every field...
Μost physics professors would agree that laboratory experience is an important part of science education. Learning through experiments encourages students to bring scientific thinking to the processes of a strong, innovative, and logical path between concepts and phenomena. Virtual labs through computer simulation-based methods of studying physics happened to be one of the most powerful...
The main idea of this study is to investigate the Dst variations in the X component of the Earth's magnetic field and their latitudinal distribution in the conditions of geomagnetic disturbance in February 3, 2022. For this purpose, data from the world database of geomagnetic observatories INTERMAGNET were used. Three sectors have been selected: (i) East Europe, (ii) West Europe, (iii) East...
Atmospheric aerosols, both natural and anthropogenic, have strong direct or indirect effects on the regional and global climate, air quality and human health. Their impacts depend mainly on the aerosol composition, particle size, and chemical-physical properties. The lidar technique is an effective instrument for near real-time observations of the aerosol mass stratification and optical...
We present one part of our long-term photometry program, targeted at studying the shape and spin state of asteroids. The CCD photometric observations were carried out in the first half of 2022 with two telescopes at the Astronomical Station Vidojevica (Serbia): 1.4m Ritchey-Chrétien-Coude "Milanković" and the 60cm Cassegrain "Nedeljković" telescope.
In this work, lightcurves, the synodical...
In this paper is presented a mechanical analysis of dollar index trend, as one of the possibilities of a new review of data obtained on the stock market exchange. The close values of the dollar index on every first day of the month from January 1, 1971 to January 1, 2021 has been considered as coordinates of unit mass particle. Dollar index close values time series were transformed to the time...
Milutin Milankovitch published his influential research ”Canon of Insolation and the Ice-age Problem” in Belgrade, Serbia, 1941. His work is important nowadays in terms of studying climate changes. In this paper we consider new scientific knowledge about solar insolation. Periodic solar activities such as sunspots and the magnetic field cycle or grand solar minimum/maximum affect the Earth’s...
Light radiation is one of the phenomena that is constantly in the attention of researchers and practitioners. The laser has become a contemporary tool that is applied in physics, technology, medicine, etc. Today we can practically not imagine our life without it, but it is necessary to obtain monochrome radiation that can be focused and directed more easily, which in special situations have a...
The spectroscopic properties of $ns^2$ ions in alkaline halide crystals are old and well-studied [1]. Regarding the spectroscopic properties of ns2 ions doped in alkaline-earth fluorides, these are less investigated. Few authors [2,3,4] have studied the optical properties of CaF$_2$:Pb$^{2+}$ crystals and LuAG:Ce single crystalline films. Recently, the effect of gamma irradiation on the...
The external geomagnetic field is known to exhibit multifractal behavior as deduced by analyzing the extensive magnetic field time series. Usually the internal magnetic field is not discussed because its changes occur with a much longer time scale. However, one can make use of the existing palaeomagnetic measurements of the dipolar (internal) field that offer a broad view on the geological...
An Individualized Education Plan (IEP) is a specific document, which provides the opportunity for the pupils with development disorders, disabilities, and children from the sensitive groups, regardless of their material status, to have the access to all levels of education1. Preparation and implementation of IEPs in physics teaching for elementary schools are done on the basis of a unique...
A number of students, as their field of interest, prefer social sciences to science. History of science can be the bridge between science and social sciences.[1],[2] Therefore, it can be a useful tool for getting students with an affinity for social sciences interested in physics and vice versa, it can get students with an affinity for physics interested in social sciences. History of physics...
This work aimed to review the optical properties of aerosol particles and the approximations developed to describe them. Aerosol particles have a significant effect on the total radiation balance. During the interaction of light with matter, two main phenomena can be observed, scattering and absorption of light, depending on matter's wavelength and optical characteristics of aerosols.
The...
In this work the seasonal – diurnal variations of lightning over two different areas: continental (Bulgaria) and maritime (Black Sea) are analyzed based on a 10 year long dataset (March 2005-February 2015) provided by the ZEUS lightning detection network operated by the National Observatory of Athens. The number of recorded flashes and the flash density at time intervals (annual, seasonal,...
Distance teaching in an electronic environment involves the application of different pedagogical approaches and methods than those used in traditional face-to-face teaching and interaction with students. At the same time, unequal opportunities for students to learn fully from a distance in an electronic environment and the lack of adequate adaptation of the distance learning process to their...
This work is aimed to study the spatial distribution of the magnetic field components variations during substorms. In this purpose, two isolated substorms, the substorm on 22 March 2013 at ~23:12 UT and the one on 14 January 2016, with central meridian over Europe have been chosen. Magnetic field data from INTERMAGNET, SuperMAG and IMAGE databases have been used. The X and Y variations due to...
We define and fully characterize the witnesses based on second moments detecting steering in Gaussian states by means of Gaussian measurements. All such tests, which arise from linear combination of variances or second moments of canonical operators, are easily implemented in experiments. We propose also a set of linear constraints characterizing steering witnesses. Given an unknown quantum...
Increased energy consumption worldwide, combined with reduced energy reserves and environmental protection, leads to the necessity of alternative sustainable energy generation methods such as thermoelectric energy conversion. In last few decades, considerable research effort has been concentrated to develop materials which can be used to transform heat into electric power. These materials have...
In this study, Ti-B coatings were fabricated by a selective electron-beam surface alloying technology. On a pure titanium substrate, a boron film with a thickness of about 1 μm was deposited by an electron-beam physical vapor deposition technique. During the deposition procedure, the accelerating voltage was 50 kV, the electron beam current was 18 mA, the beam diameter was 10 mm, and the...
In the present work, the electronic and optical properties of (B, $TM$) co-doped ($TM$ = Pt, Ta, V) anatase TiO$_2$ were investigated using modified density functional theory (DFT) calculations, in order to provide insight into the synergistic effect of co-doping with various elements on the photoactivity of TiO$_2$. We considered two combinations for each co-doped sample, with $TM$ atom...
Assessing the variability of climate extremes in changing climate is one of the greatest and most important challenges in climate science, not only because these events are rare, but also because they can be accompanied by devastating consequences. Climate change in the future could lead to an increase in the frequency, intensity and duration of extreme events and the greatest impact on the...
Introduction: According to the results from several studies [for example 1,2] high-energy positive solar particles fluxes, invading Earth are correlated with mortality from ischemic heart diseases, Ischemic heart diseases, according World Health Organization (WHO) statistics [3], are the first in the list of the 10 most frequent causes of death in 2016, regardless of the state's economic...
The magnetic properties of a ferromagnetic bilayer Ising system consisting of two monolayers with different spins 1/2 - 1 and different interaction constants coupled together with an interlayer interaction are studied by using the lowest approximation of the cluster variation method. The temperature dependences of the layer and total magnetizations are investigated extensively and observed...
In this paper we present the three cases of innovative pedagogy; the teaching of physics was conceptualized and designed in a such way to bring outcomes in order to serve the society.
The first one exploits the backwards pedagogy where physics was thought to non-physics students; the students were future teachers of primary school. By prototyping the microgenerators we promote harvesting...
A few change in the global mean temperature and noticeable changes were observed in some elements of the climate around the world. One of the most popular derivatives of the global warming is the increase of the frequency of extreme weather phenomena. The most popular extreme weather events observed in the Albanian territory during the last three decades are the days of high precipitation...
Complex networks theory provides methods and tools for studying the structure and dynamics of various complex systems. Real complex networks, although representing very different complex systems, have some common properties. They have broad degree distribution, small average shortest path compared to their size, high clustering, and degree-degree correlations. Knowledge about how these...
A social group is a characteristic element of every social system on a mesoscopic level. The growth of social groups is indissolubly connected to the structure and dynamic of a social system. Social systems differ in their purpose and the type of communication and activity their members engage in. At first glance, one would expect that the growth of social groups in these different systems is...
The direct approach to model evaluation is to compare regional climate model (RCM) output with observations and analyze the resulting difference in order to identify deficiencies in the model itself which can be reduced by its improvement or taken into account for understanding and interpretation projections of future climate change. In previous studies, it was noticed that most of EURO-CORDEX...
The world consists of millions of different living organisms. Through their huge diversity in terms of characteristics they have managed to live in all the possible extreme conditions in the planet that we live in. Every organism had millions of years to adapt to its environment and the results of this continuous evolution are there to be studied in order to benefit human lives through the...
Since the very beginning, Regional Center for Talents “Mihajlo Pupin” in Pančevo had a physics group. Over time, the number of classes has grown, but so did the number of students and mentors. Consequently, the achievements on national and even international competitions in physics were growing steadily. After first few years spent in experimenting different possibilities in the field of work...
The idea of this paper is to develop a method for determination thermal diffusivity, linear expansion coefficient and thickness of a semiconductor sample from photoacoustic phase measurement by using neural network. The neural network has been trained on a large basis of photoacoustic phases obtained from a theoretical Si n-type model in the range of 20Hz to 20kHz. The advantages of using a...
Despite the impressive success of the Standard model (SM) in describing nature it still fails in finding the answers for a few astrophysics phenomena, including the lack of antimatter in the Universe and what Dark Matter is made of. Recently, models proposing the existence of a whole new world of particles, the so-called Dark sector (DS), regained interest. The PADME experiment at LNF-INFN...
Optical emission spectroscopy technique was used to measure rotational and gas temperature distribution in the cathode-sheath region of an abnormal glow discharge operated in hydrogen. The rotational temperature of excited electronic states of H2 was determined from the relative line intensities of the R-branch of the Fulcher-$\alpha$ diagonal band $d^3\Pi_u^+, \nu' = 0 \rightarrow...
We report results of an experimental study of shapes of Ne II 369.421 nm, Ne II 371.308 nm, and Ne II 372.711 nm lines in the cathode sheath (CS) region of an abnormal glow discharge in pure neon. The experimental profiles were studied using optical emission spectroscopy (OES). Several strong ionic neon lines from the near UV region exhibit extensively broadened wings of their spectral...
Stark width and shift simultaneous dependence on the upper level ionization potential and rest core charge of the emitter has been evaluated and discussed. It has been verified that the found relations, connecting Stark broadening parameters with upper level ionization potential and rest core charge of the emitters for particular electron temperature and density, can be used for prediction of...
A software application developed from open-source code libraries has been used to analyze digital video recordings of physical system evolution. The process of calcium carbonate tablet decomposition in deionized water was recorded with a digital video camera at 12 Mp resolution and 30 frames per second. The tablets were formed by compressing micronized CaCO3 powder with a cylindrical press...
Contrary to general belief, quantum gravity can have important consequences for observations in present day experiments. It can predict parameters of the standard model of particle physics. Functional renormalisation permits the computation of fluctuation effects of the metric. Quantum gravity can be formulated as a non-perturbatively renormalisable quantum field theory, in close analogy to...
The quantum-mechanical amplitude for the transition from an initial state i to a final state f can be represented in terms of Feynman’s path integral. This integral includes all histories of the transition i -> f, i.e. the sum over all paths in space with fixed end points. In the classical limit this sum reduces to a sum over all classical paths for which the action S is stationary. In quantum...
As quantum technologies advance, the ability to engineer increasingly large quantum devices has experienced rapid development. In this context, the verification of large entangled systems represents one of the main challenges in the employment of such systems for reliable quantum information processing. Though the most complete technique is undoubtedly full tomography, the inherent exponential...
The history of scientists that have been awarded a Nobel Prize is by now rather extensive, the history of scientists that have been awarded more than one Nobel Prize is (for that very reason?) also rather large. The list of scientists that have not been awarded Nobel Prizes is longer still. In this talk a 101 lesson on how the Nobel Prize institution works will be given by studying the...
Geant4 is a toolkit for Monte Carlo simulations of the particle transport through matter. It has a complete set of routines for modelling particle trajectories and interactions: geometry and materials, physical processes, event generation, detector response and analysis and visualisation. It has been used in wide range of applications in high energy, nuclear and accelerator physics, as well as...
The Commensal Radio Astronomy FAST Telescope Survey (CRAFTS) is underway. With over 2,000 hours complete (out of 11,000 planned) we have mapped significant sections of the sky visible from the Five Hundred Meter Spherical Aperture Telescope (FAST) located in Guizhou, China. The Survey itself represents a technological leap forward in radio telescope observation techniques which allows for...
Mineral dust is one of the most important aerosol types in terms of mass and optical depth. It affects radiation and alters liquid and ice cloud properties, as well as precipitation processes. Once dust particles are deposited at the surface, they provide micronutrients to the ocean or to land ecosystems, affecting fishery and agriculture activities. Moreover, very high concentrations of dust...
Measurements of azimuthal anisotropic flow provide valuable information on the properties of the quark-gluon plasma created in relativistic collisions of heavy ions. In addition, strong fluctuations of the anisotropic flow allow for an efficient selection of the events corresponding to a specific initial geometry. This selection technique, Event Shape Engineering, has been used to measure the...
Understanding the behavior of strongly correlated electronic systems is one of the central challenges in condensed matter theory. In the focus of these efforts are the cuprate superconductors: They exhibit a highly universal strange metallic behavior, from the superconducting critical temperature, up to the highest accessible temperature. The nature of the strange metallic state, its...
The elliptic flow harmonic $v_{2}\{2k\}$ is determined using Q-cumulants of different orders, with $k=1,...,5$, for 5.02 TeV PbPb collisions. The results were obtained using data from the CMS experiment at the LHC. The $v_{2}\{2k\}$ values show an ordering, with $v_{2}\{2\} > v_{2}\{4\} > \approx v_{2}\{6\} > \approx v_{2}\{8\} > \approx v_{2}\{10\}$. The hydrodynamics behavior of the medium...
We present a novel framework ebe-DREENA, based on a state-of-the-art dynamical energy loss model, which can include any temperature profile from bulk medium simulations. The framework is fully optimized to exploit different state-of-the-art medium evolutions - both event-by-event hydrodynamics and kinetic transport theory. It does not use fitting parameters within the energy loss model,...
With this talk, Dr. Enrique Sánchez would like to give an inspirational view about professional activities and opportunities for physicists outside academia based on his personal experiences, putting special focus on the science policy activity, where he develops his professional career representing the European Physical Society in Brussels.
Over the years High Purity Germanium (HPGe) detectors proved to be an excellent practical tool and as such have established their todays wide use in low background γ-spectrometry. One of the advantages of gamma ray spectrometry is its easy sample preparation as chemical processing and separation of the studied subject in not required. Thus, with a single measurement one can simultaneously...
In the last two decades, part of the observational time at Bulgarian National Astronomical Observatory (BNAO) Rozhen was dedicated to asteroid observations. Even though we had limited time, we collected enough information to proceed with differential photometry on many asteroids. Using a combination of lightcurves of an asteroid, gained from observations at several oppositions, we were able to...
A project titled ”Natural and anthropogenic factors of climate change – analyzes of global and local periodical components and long-term forecasts” funded by the Bulgarian National Science Fund allows us to review and stream studies of Bulgarian scientists in order to identify the role of natural and anthropogenic factors causing climate change in global or regional scale. The Natural factors...
The interlayer magnetothermopower of the organic superconductor $\kappa-\rm (ET)_2Cu(NCS)_2$ is studied at temperatures down to 0.5 K and fields up to 32 T. Analysis of the background magnetothermopower show that at low temperatures it is negative and exhibits an upturn at higher field, producing a dip at a field close to the upper critical field $B_{c2}$. There are clear magnetothermopower...
NA61/SHINE (SPS Heavy Ion and Neutrino Experiment) is a fixed-target experiment at the CERN Super Proton Synchrotron. One of its research projects is the systematic measurement of hadron production in proton+proton, proton+nucleus and nucleus+nucleus interactions. These studies are performed in particular to study the predicted signals of the onset of deconfinement and search for the critical...
A different alternative approach to calculate the ratio of the surface to volume components of the nuclear symmetry energy is proposed in the framework of the coherent density fluctuation model (CDFM). An alternate expression (scheme II) for the ratio is derived consistently within the model. This expression appears in a form more direct and physically motivated than the expression (scheme I)...
We study a quasi two-dimensional Josephson junction of d-wave superconductors through two ferromagnetic layers in between. Ferromagnets are separated by isolator barrier. In the frame of Bogoliubov – de Gennes formalism we solve scattering problem to find current-phase relations in the case of $d_{x^2-y^2}$/ferromagnetic barrier/$d_{xy}$-wave superconductor junctions. We find that...
Urban flooding in Albanian are mostly consequence of extreme daily precipitation that very often causes a huge economical and social impact. Events of extreme daily precipitation, mainly their frequency and severity play an important role and also control the long-term variation of the seasonal and annual precipitation amounts. To have a long term trend of the phenomenon and to point out the...
The CMS experiment at CERN uses a two-level triggering system that is composed of the Level-1 (L1), instrumented by custom-designed electronics with an output rate of 100 kHz, and the High Level Trigger (HLT), streamlined version of the offline software reconstruction running on a computer farm, with around 1.5 kHZ of physics rate stored for further analysis. New trigger algorithms and also...
Bulgarian National Astronomical Observatory Rozhen is located in the Rhodope Mountains at about 1750 m above sea level. The astronomical observatory is the biggest one-time Bulgarian investment in scientific infrastructure and a leading astronomical center in the South-East Europe. So far, the observatory has four telescopes: 2-m RCC multipurpose telescope equipped with four new professional...
Metamaterials and nanoplasmonics bridge the gap between conventional optics and the nanoworld. Exciting and technologically important capabilities range from subwavelength focusing and stopped light to invisibility cloaking, with applications across science and engineering from biophotonics to nanocircuitry. In the talk, we shall present past and recent advances in this exciting field,...
High Energy Particle Physics is constantly evolving towards increasing the complexity of the detectors and the amount of experimental data. Micromegas-type detectors offer great resolution and are able to operate reliably at high data-taking rates. We trained a convolutional neural network using simulated muons to identify their tracks and determine if they originate from the supposed...
While ground-state properties of the Holstein model are well understood by now, the evaluation of its finite-temperature spectral properties has received more attention only recently [1, 2]. Here, we develop a hierarchical equations of motion (HEOM) approach to compute real-time single-particle correlation functions and thermodynamic quantities of the Holstein model at finite temperature [3]....
Polarization is a property of light widely used as a source of additional information in astronomy. The primary source of polarization in the atmosphere is the scattering by gas molecules although meteorological conditions, sky pattern, underlying surface reflectance, etc. may influence the observed sky polarization. In order to explicate polarization measurements correctly, it is important to...
One of the most important difficulties in the fight against the environmental pollution and its consequences (burden on human health, climate change and others) is the development of alternative electric power sources in the place of the polluting electric power plants consuming fossil fuels. Nuclear power and nuclear plants are one of these alternatives which present a lot of advantages like...
The nuclei with few proton and neutron particles (holes) away from doubly-magic nuclei are the simplest nuclear systems in which both nuclear collectivity and the two-fluid nature of the nuclear matter can simultaneous be manifested. The relatively small number of valence particles (holes) allows the low-lying collective states in these nuclei to be described in the shell-model framework. The...
Finding eco-friendly replacement for CF4 while preserving performance and long-term operation of gas discharge detectors is of the high environmental and economic importance. Tetrafluoropropene (C3H2F4) with the trade name HFO1234ze appeared as promising candidate with low GWP. Using gas mixture of 40% Ar, 58% CO2 and 2% HFO1234ze, longevity tests were performed with β-source 90Sr and...
First I shall discuss possibilities and choices after being awarded the bachelor’s, master’s and PhD degree in physics or applied physics. I shall talk about advantages and disadvantages of different career paths and illustrate the relationship between job security and personal freedom for the various categories. After giving tips on how to decide, I shall focus on a career in academia, where...
The rainfall affects the condition of arable land and its agricultural productivity. This study aims to analyze the impact of rainfall erosivity on irrigated and non-irrigated arable land and to create relevant statistics on the differences observed over specific periods in Romania. The database is made up of historical data on rainfall erosivity from the European Soil Data Center in...
The interplay between single-particle and collective degrees of freedom is one of the most important and debated features in the study of the nuclear structure of medium mass nuclei. For neutron-rich nuclei with protons in the fp shell, nuclear structure observables indicate an onset of collectivity for neutron number N$\sim$40. Adding just a few particles/holes to the $^{68}$Ni core leads...
It is generally accepted that the dynamical mean field theory (DMFT) gives a good solution of the Holstein model [1], but only in dimensions greater than two. Here we show that the DMFT, which becomes exact in the weak coupling and in the atomic limit, provides an excellent numerically cheap approximate solution for the spectral function of the Holstein model in the whole range of parameters...
One of the current problems of our contemporary time is related to changes in the climate of local, as well as global scope. We offer an analysis of long-term time series of meteorological data from different weather stations in Bulgaria. The main portion of the analyzed data are monthly average values of temperature, precipitation, atmospheric pressure, and they can be related to different...
Compact Muon Solenoid (CMS) is one of the two general purpose detectors at the Large Hadron Collider (LHC). It underwent several upgrades in preparation for LHC RUN-3. Among them is the installation of 144 new muon detectors based on Gas Electron Multiplier (GEM) technology at Station 1 in the endcap region. In each endcap, there are integrated RadMon (active radiation sensor) units that are...
Through analytical arguments, numerical calculations and comparison with experimental data, we show that the ratio of high $p_{\perp}$ observables $v_2/(1-R_{AA})$ reaches a well-defined saturation value at high $p_{\perp}$, which depends on the spatial anisotropy of quark-gluon plasma formed in ultrarelativistic heavy ion collisions. By using our recently developed DREENA framework, which can...
The coupling of Frenkel excitons (FEs) and intramolecular vibrations in an organic layer as a part of microcavity has been studied in the paper. Two cases are treated: a) uniaxial layer of point group 4 (optical axis is supposed perpendicular to the layer); b) monoclinic anthracene-like layer with monoclinic axis b perpendicular to the layer. The exciton-phonon coupling produces the vibronic...
The very forward region is one of the most challenging regions to instrument at a future e+e- collider. Machine-detector interface at CEPC will include a calorimeter dedicated for precision measurement of the integrated luminosity at a permill level or better. We discuss a feasibility of such precision from the point of view of systematic effects arising from luminometer mechanical precision...
The proposed Future Circular Collider (FCC) at CERN aims to continue the exploration of open questions in particle physics beyond the LHC and its high-luminosity upgrade in a staged research programme, integrating in sequence lepton (FCC-ee) and hadron (FCC-hh) collider programmes, and with the option of a hadron-electron collider (FCC-he), to achieve further understanding of the Standard...
Neutral current quasielastic (anti)neutrino scattering cross sections on a $^{12}$C target are analyzed using a realistic spectral function $S(p,E)$ that gives a scaling function in accordance with the ($e,e'$) scattering data. The spectral function accounts for the nucleon-nucleon (NN) correlations by using natural orbitals from the Jastrow correlation method and has a realistic energy...
A well-known paradigm about the origin of Galactic cosmic rays (CRs) is that these high-energy particles are accelerated in the process of diffusive shock acceleration (DSA) at collisionless shocks (at least up to the so-called “knee” energy of $10^{15}$ eV). Knowing the details of injection of electrons, protons and heavier nuclei into the DSA, their initial and the resulting spectrum, is...
Graphene (G) grown on Ni(100) forms the stripped moiré pattern that can be described as an alternate arrangement of valleys, where G is close to the nickel substrate and interacts with it rather strongly, and ridges, where G is far away from the substrate and is almost free-standing [1]. When metal adatoms are deposited on G/Ni(100), the structural differences between the valleys and the...
A project for non-destructive assay (NDA) of radioactive waste at the Studsvik nuclear decommissioning site is presented. The concept is based on a novel 3D radiation imaging modality for special nuclear materials (SNM) - neutron-gamma emission tomography (NGET) that was first demonstrated for nuclear security applications [1,2]. NGET has been recognized by the Royal Swedish Academy of...
Over the past several years, a foremost development in cosmology has been the rise of the so-called Hubble tension. This refers to the disagreement between the measurements of the expansion rate of the universe - the Hubble constant (H0). Direct measurements of H0 using the astronomical "distance ladder" find H0 of about 67 km/s/Mpc, while the analysis of the cosmic microwave background...
In this talk I will provide an overview of the current quantum ecosystem and its funding landscape. I will then follow with career opportunities, including my career path and the role of QURECA, to finish with some advice on how to improve your CV and prepare yourself for a career in quantum.
Thermal radiation is omnipresent, radiated by any object in the universe, including universe itself. For a long time, Planckian radiation was used as a reliable “fingerprint” of a thermal state of a matter – human body, homes, industrial objects and, regrettably, weapons, among many other things [1]. Here we provide an overview of thermal measurements in biophotonics in order to study how life...
This article concerns an uncertainty and sensitivity investigation of certain parameters in the In-Vessel Melt Retention (IVMR) test case for VVER-1000/v320. It has been used the ICARE and CESAR modules of ASTECv2.2b severe accident computer code to describe the basic parameters behaviour and the main phenomena arising during the IVMR in VVER1000 reactor design. The external vessel water...
Currently, rechargeable ion batteries are attracting more attention than others due to their advantages as recycling charging devices with high energy capacity, high performance, and easy adaptation to industry [1,2]. Lithium-ion batteries (LIBs) are currently the best performing batteries mainly due to their relatively high energy densities, good stability, and low self-discharge. Their main...
In this talk, I will discuss how Quantum Physics give us a new type of information, and how it can be exploited to develop new and revolutionary paradigms for computation, communications, and sensing. Furthermore, I will discuss the state of the art of this novel domain, and the challenges and opportunities lying ahead.
We consider the charged massless Dirac fields in the background of $4$-dimensional Einstein-Born-Infeld dilaton black hole spacetime. We derive the analytical spin-half quasinormal modes, whose Dirac equations are obtained in terms of the hypergeometric functions. The stability analysis of those black holes under the charged Dirac perturbations is also discussed. Obtained results are...
Introduction
Retrospective/accidental dosimetry, seeks for materials that can be used as probes for the dose assessment, when there is no other available data, from personal or environmental monitoring, during nuclear accidents. When there is uncontrollable release of radiation, it is important to determine the dose of the exposed population, in order to take the corresponding measures to...
The predictability of mesoscale convective phenomena is limited by the rapid transfer of energy between the large-scale and microscale as the result of the initial conditions, the natural constraints imposed by synoptic-scale forcing, and physical processes. Uncertainties are the greatest challenge when predicting the initiation of convection as the most difficult aspects of convection, due...
Symmetry determines forms of band structures in the vicinity of special points in the reciprocal space of one-, two- and three-dimensional materials. After short introduction to the complete classification of linear dispersions in 2D materials,$^1$ we will focus on a particular example. A tight binding model on a crystal with four sites per primitive cell that belongs to grey layer single...
Big Bang Nucleosynthesis (BBN) is one of the most reliable tests of Beyond Standard Model (BSM) physics due to the remarkable concordance between the theoretically predicted and the derived from observations abundances of light elements produced primordially. Recently the primordial light elements D and He-4 were determined with higher accuracy. This allows to update and strengthen the Big...
Although the Intergovernmental Panel on Climate Change (IPCC), the United Nations body for assessing the science related to climate change, gives clear quantitative pictures about climate change and increasing the mean Earth’s temperature due to increasing greenhouse gas concentration, the general public concern and scientific debate still continue [1]. A clear identification of the...
Inorganic metal-halide perovskites have drawn much attention as candidates for producing low cost high-performance solar cells having efficiency reported as high as 20% in single-junction architecture. Their electronic and structural properties have been the case of intense study in both experimental setups and computational simulations. Since solar cells are expected to perform outside of...
S-Z is an effect, which consists in the inverse Compton effect of the hot electronic gas interacting with Cosmic Microwave Background (CMB) photons passing through Intra Cluster Medium (ICM). Building more accurate profiles for temperature and density of hot electronic gas, concentrated in the center of clusters of galaxies, is a constant problem in survey of Sunyeav Zel’dovich effect (SZ)....
The aim of this study was determination of natural (226Ra, 232Th, 40K) and artificial (137Cs) radioactivity levels in thirty soil samples collected from different locations in Albania. The obtained results provides essential information concerning reference baseline concentrations of natural and artificial radioactive isotopes and environmental pollution. The main contributors of natural...
General relativity (GR), i.e. Einstein theory of gravity, is recognized as one of the best physical theories -- with nice theoretical properties and significant phenomenological confirmations. Nevertheless, GR is not a complete theory of gravity and there are many attempts to modify it. One of the actual approaches towards more complete theory is nonlocal modified gravity. Nonlocal gravity...
We will discuss an introduction to the concept of quantum information and its application to quantum cryptography. I will go through an educational approach based on a laboratory demonstration of the BB84 quantum cryptography protocol. Quantum cryptography is based on quantum key distribution through a quantum channel. In the BB84 protocol the quantum state of the polarization of the photons...
The aim of this research was to analyze the earthquake hazard of the Eastern Macedonian seismogenic zone by determining the a and b values in Gutenberg-Richter law. For this purpose, the previously known division of the zone to six epicentral areas was used. The b and a values were calculated for the epicentral areas where the seismic data permits, using the least square method. Using...
Maxwell's action in vacua is scale-invariant. This causes singularity in the fields and infinite self-energy. By breaking this symmetry one may remove the singularity as well as make the self-energy finite. In the context of the spontaneously broken scale-invariant nonlinear electrodynamic with a magnetic dominance, we introduce black a hole solution.
We study the physical properties of...
We report BR-bands monitoring of 6 massive star candidates selected in a 10x10 sq. arcmin field in north-east quarter of the IC342 galaxy on the base of our B+H$\alpha$ images obtained with the 2m RCC telescope at NAO Rozhen, Bulgaria. We analyzed 2.3 yr BR-light curves of the objects. The candidates demonstrate photometric variations smaller than 0.2 mag, and no overall brightness changes has...
Analyzing our catalog of active-region-related activity events of solar cycle 24, we pay special attention to solar flares. In addition to Geostationary Operational Environmental Satellite (GOES) soft X-ray flare listing data that we investigated to associate solar flares with active regions, we added microwave flare observations by the Badary Broadband Microwave Spectropolarimeter (BBMS). ...
Hidden symmetries provide a powerful tool for finding exact solutions in multifield cosmological models. I will show how, using such symmetries, one can find inflationary solutions in two-field models, which lead to the generation of primordial black holes. I will also discuss an exact solution in a two-field cosmological model, which describes dark energy. This solution is obtained with the...
There is a growing amount of evidence of possible connections between the geomagnetic field and ozone production in the lower stratosphere. They emphasize the control the geomagnetic field can exercise on production and distribution of ozone, thus inflicting minor changes in climate patterns. In the present study we investigate such connection for other atmospheric gases, namely water vapor....
Ultracold-atom simulators have provided important insights into charge and spin transport in the two-dimensional Hubbard model [1, 2]. However, theoretical tools to compute quantities directly measured in experiments, such as space- and time-resolved charge/spin densities following a quench of an external density-modulating field, are still scarce. Here, we devise the alternating-basis quantum...
Chemical reactions in the avalanche plasma lead to formation of deposit on the electrode surfaces thus causing degradation of operating characteristics of gaseous detectors and limiting their long-term use in particle physics experiments. Various surface non-destructive complementary techniques were employed for detailed characterization of deposit accumulated on the surface of electrodes...
Heavy-ion collisions at relativistic energies offer an unique opportunity to investigate the properties of highly excited dense nuclear matter in the laboratory. Strange hadron production in nucleus-nucleus collisions is believed to be an important tool to study the dynamics of the produced QCD matter. Transverse momentum spectra of strange particles (${\rm K}^{0}_{\rm{S}}$, $\Lambda$,...
Even the environment at future e+e- colliders is practically QCD background free, there is a large number of processes with high cross-sections and/or similar topology as the Higgs signal. Minimization of the statistical uncertainty calls for optimized event selection w.r.t. the statistical significance. This is where the Multivariate Analysis (MVA) is employed, separating the signal from...
Bose-Einstein condensate is state of matter that is the future of the quantum computers. One of the crucial properties of Bose-Einstein condensate is quantum tunneling. In this paper are listed previously achieved results by other authors considering the factors that affect tunneling in Bose-Einstein condensate, such as form of interaction between particles, shape of potential well and the...
It is found from viscous hydrodynamics that the QGP created in ultra relativistic heavy-ion collisions has different longitudinal and transverse pressures at early times. This occurs due to the large momentum space anisotropy in the p_T-p_L plane. This momentum space anisotropy can cause plasma instabilities that are largely responsible for the thermalization and isotropization of the system....
Lead selenide (PbSe) is a semiconductor of the cubic structure whose bandgap is 0,27 eV. It belongs to a group of essential materials for developing uncooled mid-IR detectors. This material also proved to be an excellent thermoelectric, offering a few advantages compared to other materials. It is also worth mentioning that doping can readily modify its properties. In this work, we have studied...
In experiments searching for rare nuclear events (neutrinoless double beta decay, dark matter, etc.) detailed knowledge of background is necessary in order to achieve reliable analysis and interpretation of experimental data [1]. In the ground-based laboratories, the significant contribution to the background of the detector spectrum originates from the interaction of cosmic rays with...
Slow evaporation as a crystallization technique can allow the growth of large oriented crystals. In the experiments performed, sodium chlorate crystals were obtained by evaporating microdroplets of a saturated aqueous solution both at ambient conditions and at a constant temperature of 31.5ºC in a closed container. The solution was saturated at a temperature of (31.5±0.1)ºC. A 5 μL drop of the...
A simple framework for obtaining simultaneous energy and interaction position measurements from gamma particle interactions was developed in simulation and in hardware. The framework provides a method for obtaining the time of arrival and three methods for obtaining the interaction position, centroid, multiple maxima and an ML algorithm trained by simulation. Results of the simulations and the...
Determination of 226Ra and 222Rn activity concentration in water has been recognized as one of the most important tasks in the preservation of public health, since increased content of these radionuclides in drinking water may lead to increased health risk. Generally, the presence of 226Ra in water samples is potentially dangerous due to its radiotoxicity and has been related to the cancer of...
In this talk we discuss the CP violation in the Higgs sector under assumption that Higgs is a mixture of CP even and odd states. Study is done in ZZ-fusion, at the intermediate energy stage of CLIC, in full simulation of a detector for CLIC and machine and physics related backgrounds. By measuring the properties of electron and positron in the final state, selecting the Higgs dominant decay...
Microscope resolution is the shortest distance between two points on a sample that can be distinguished as separate entities. Due to the wave nature of light and the phenomenon of diffraction, it is fundamentally limited: even under theoretically ideal conditions and optical components, the microscope has a finite resolution.
In this paper, we determined lateral and axial resolution of a...
The research topic is calculation of the drift velocity of electron transport in $N_2$ gas under the influence of an external crossed electromagnetic field, E x B. A Monte Carlo simulation code has been used to obtain non-equilibrium electron energy distribution function within one oscillation of external crossed fields. In simulation, E is aligned with the z-axis, while B is parallel with...
Among various ferrites, nanosized nickel ferrite is one of the most frequently employed materials for production of electronic materials due to a set of outstanding physical and chemical properties. Doping with various atoms is a common choice when it comes to the development of new materials with target properties. Rare-earth elements have been frequently used in different research areas in...
Magnetization of two dimensional O(3) Heisenberg ferromagnet is investigated using perturbation theory for type-B Nambu-Goldstone bosons, quantum Monte Carlo simulations an nonlinear spin wave theory.
By calculating loop corrections to the magnon self-energy, in combination with QMC data and spin wave theory, we discuss the applicability of effective field theory for two dimensional O(3)...
We are reporting the results of the first experimental determination of the collision-energy dependence of the muon transfer rate from the ground state of muonic hydrogen to oxygen in the energy range below 100 meV. These results shed new light on the kinematics of the processes involving exotic atoms, and may serve as benchmark for the full-scale quantum-mechanical calculations of low-energy...
Haldane model is devoted to explore the electron spectra of honeycomb hexagonal 2D lattice. In this paper we treat its connections with the excitonic spectra of two types of molecular excitations, Frenkel excitons (FEs) and Charge Transfer Excitons (CTEs) and study the generalized Haldane model in 2D Lattices of hexagonal symmetry. Excitations with transition dipole moment perpendicular to the...
The emphasis of the talk will be related to the physics studies at the KAHVELab, and on top of that I will be mentioning current status of hardware development at our laboratory.
The analysis focuses on FCNC decay channel $pp \rightarrow DD \rightarrow XjZj \rightarrow 4j 2 \mathcal{l}$ where $X$ represents a boson that decays hadronically and $Z$ boson which decays leptonically. The $D$...
The mechanisms of crystal growth depend on the temperature and supersaturation of the solution. As a result of their competition, different growth regimes may occur. The results of previous studies have shown that in the range of supersaturation of 0.66−1.56%, the {100} sodium chlorate crystal faces grow according to the model of spiral growth [1]. In order to determine the possible influence...
Wall painting technique identification is an ongoing problem, as identification criteria are still a matter of discussion. The main purpose of this study is to examine the possibility of detecting organic binders as a function of the maximum developed temperature in the case of a fire. This is important in the case of wall paintings, as the presence or absence of organics is one of the...
We study Josephson effect in a junction with arbitrarily oriented d-wave superconducting electrodes connected through two ferromagnets with noncollinear magnetizations. We solve the scattering problem based on the Bogoliubov-de Gennes formalism, extended to the case of anisotropic superconductors and presence of spin flip scattering due to ferromagnet interlayer. We investigate mutual...
ZnO nanoparticles (NPs) applied in sufficient doses exhibit cytotoxic effect in vitro [1]. However, selective cytotoxicity towards certain cell types is also registered [2]. Proposed selectivity of ZnO NPs for cancer cells is an issue of special importance for the development of new drugs based on ZnO. By generating the reactive oxygen species (ROS) and by acting themselves as an electron-hole...
We present a resonant inelastic and elastic X-ray scattering (RIXS/REXS) study of epitaxial YBa2Cu3O7/Nd1-x(Ca1-ySry)xMnO3 heterostructures (NYN). We show that the Copper charge density wave (Cu-CDW) order of the near optimally doped YBa2Cu3O7 layers can be strongly modified via the hole doping and tolerance factor of Nd1-x(Ca1-ySry)xMnO3, i.e. by changing x and y.
At x=0.35 we observe a...
Iron oxide based magnetic nanoparticles (Fe3O4, gamma-Fe2O3), are widely investigated in biomedicine, especially as diagnostic and therapeutic agents. They can be used as imaging contrast agent, drug-delivery nanocarriers, intracellular hyperthermia mediators, etc. If their size is in the range of 4-28 nm, they show superparamagnetic behavior, with magnetic saturation comparable to that of...
In this talk we address a full simulation of experimental measurement of the Standard Model Higgs boson decaying to two photons at 3 TeV center-of-mass energy at Compact Linear Collider (CLIC). Since photons are massless, they are not coupled to Higgs boson at the tree level, but rather are created in a loop exchange of heavy particles either from the Standard Model or beyond. Any deviation of...
CLIC is a mature option for a staged linear electron-positron collider that could run from 350 GeV up to 3 TeV center-of-mass energy. Measurements of the product of a Higgs production cross-section and branching ratio of the Higgs boson, serve as input to a global fit of Higgs properties (couplings and width) in a model-independent or model-dependent way. In this talk we present the full...
The recent synthesis of two-dimensional (2D) silicon carbide (SiC) [1] experimentally proved the existence of 2D carbides, a new class of semiconducting materials with the honeycomb structure. Considering the point defects, one of the simplest structural deformations in 2D materials, we examined the prospect of employing them for the band-gap engineering of a SiC monolayer. Applying density...
Electron-phonon (e-ph) interaction is responsible for majority of transport phenomena in condensed matter. In this work, we consider the short-range (localized) e-ph interaction described by the Holstein Hamiltonian. We develop numerically exact path integral Monte Carlo (PIMC) methods to obtain current-current correlation functions (CFs) and polaron mobility of one-dimensional Holstein...
The Monastery of the Ascension is located in Sykea, a village of Elassona town near Mount Olympus, with a significant contribution in the area regarding charity and culture [1]. Its catholicon was constructed and painted in about the mid-17th century, while the iconographer remains unknown. The purpose of this study is the materials characterization of the catholicon’s wall-paintings and the...
Muonium formation in muon-hydrogen ($\mu^+-\rm{H}(1s^1)$) and muon-helium ($\mu^+-\rm{He}(1s^2)$) charge-exchange collisions is considered at intermediate and high impact energies, from 10 keV to 1 MeV. The prior form of the three-body boundary-corrected first Born approximation (CB1-3B) [1] is used for calculations of the state-selective total cross sections $Q_{nl}$ for single-electron...
In the current work, we present a modeling approach for simulating mesoscopic phenomena related to lubrication. Our geometry allows a variable confinement gap and a varying amount of lubricant in the gap. We have implemented and compared several coarse-grain molecular dynamics descriptions of an ionic liquid (spherical model and model with cation tail) as a lubricant that can expand into...
Precise spectroscopy of light atomic and molecular systems gives us new insides in the fundamental laws and physical constants of nature [1]. In particular, exotic atoms like antihydrogen and antiprotonic helium could also allow comparison between matter and antimatter characteristics and test of CPT symmetry [2]. From theoretical point of view, development of very accurate techniques like...
We discuss cosmological perturbations of the scalar type in the spatially flat FRWL background during inflation. There are five independent scalar perturbations. Four of them are perturbations of the FRWL metric and the fifth one represents perturbations of a scalar field. As usual, a scalar field is used to describe dominant (perfect) cosmological fluid responsible for inflation [1].
These...
In a series of recent papers we have suggested to use the information on the so-called difference asymmetries (i.e. the difference between the asymmetries in the production of particles and their anti-particles) in Semi-inclusive deep inelastic scattering (SIDIS) in order to determine the Boer-Mulders functions. Here we comment on how our analysis can be used to find the mean value of the...
The DBI Langrangian (or a family of DBI Lagrangians) has been known and widely considered in many different fields of physics.
For instance, classical and quantum dynamics of tachyon systems have been examined, describing spatially homogeneous scalar fields, in the limit of classical and quantum mechanics.
Understanding and modelling of these systems are of particular importance in the...
Objective diagnosis on site, in real time is still a challenge for skin lesions, specifically pigmented skin lesions. Different optical tools are currently under development or clinical implementation process to assist this process. Some of the techniques applied are diffuse reflectance spectroscopy, fluorescence spectroscopy, even confocal fluorescence microscopy. They provide information...
Our system consists of planar magnetic structures created by the assembly of point dipoles. The departure point of this work is the known degeneracy of ground states in planar square and triangular packings. The square lattice has a particularly interesting antiferromagnetic ground state exhibiting a transformation from percolating antiferromagnetic chains of dipoles pointing head-tail to a...
Polarimetry is one of the emerging optical modalities for implementation in diagnostic. Polarimetric measurements are mostly informative about structural changes in the tissue. Collagenosis diseases affect connective tissue and arise from changes in collagen structure or metabolism. Their diagnosis is quite challenging, since the symptoms are not unambiguous.Considering that collagen is...
Polymer nanocomposites are prepared by a simple and environmentally friendly technique. First, sheets of isotactic polypropylene (iPP) and atactic polystyrene (aPS) were prepared by compression molding with Servitec Polystat Press 200 T at 473.15 K and 3.0 MPa pressure followed by quenching in water at room temperature. The polymer sheets thus prepared were then immersed separately in three...
Installation of a MIP Timing Detector (MTD) to the CMS detector will introduce new capabilities and will allow precise timestamp assignemnt to traversing charged particle up to pseudorapitidy of |eta|=3. Targeted timing resolution is 40 ps per track, which will help reduce the pile-up conditions expected at the High-Luminosity LHC. The endcap region of the MTD, Endcap Timing Layer (ETL), will...
Introduction
The European Standard EN1788 (2001) [1] defines the procedure of silicate minerals’ extraction from food products and their use to distinguish irradiated from non-irradiated food products, based on Thermoluminescence (TL). The extraction of the minerals is important since most of the food products, such as dried oregano, are not heat-resistant, thus TL cannot be applied to...
Building materials may contain to some extent naturally occurring radioisotopes 226Ra, 232Th (from uranium and thorium decay chain) and primordial radioisotope 40K. Those materials are often referred to as NORM (Naturally Occurring Radioactive Materials) [1, 2]. Owing to the presence of radioisotopes, using NORM in buildings can present a potential health risk to the population, due to the...
Self-avoiding polygons with bending stiffness and attractive nearest-neighbor interactions, are studied on three simplex fractal lattice. Via an exact set of restricted generating functions, the number of contacts as a function of the Boltzmann weights associated with stiffness and interaction energies, is calculated numerically. Calculation reveals that the number of contacts is...
Harmonium is a system of two electrons whose Coulomb interaction with the nucleus is replaced with harmonic potential. Such a theoretical system is widely used for studying density functional theory, electron correlation, entanglement and black body entropy. It is of great importance to examine spherically confined harmonium in plasma environment, since the results can be useful for...
Mobility of charge carriers is a physical quantity that determines the performance of semiconductor electronic and optoelectronic devices. It is still a significant challenge to predict its value starting from the crystal structure of the material. To date, such calculations have been performed only for few semiconductor materials, such as Si, GaAs and GaN [1]. In this work, we study the...
A phenomenological framework for the relaxation dynamics of quantum lattice model with multi-well potentials is given in the case of deformed $Sn_{2}P_{2}S_{6}$ ferroelectric lattice. The framework is based on the combination of statistical equilibrium theory and irreversible thermodynamics. In order to study these dynamics in a connected way we assume that the dipole ordering or polarization...
The forthcoming measurements at RHIC and LHC will generate heavy flavor data with unprecedented precision, providing an opportunity to utilize high-$p_T$ heavy flavor data to analyze the interaction mechanisms in the quark-gluon plasma. Experimentally observed suppression mass hierarchy, and investigation of the dead-cone effect in radiative energy loss, inspired us to study the mass hierarchy...
The superconducting quantum interference proximity transistors, abbreviated SQUIPTs, are interferometers based on a Josephson junction (JJ) that use the superconducting proximity effect to achieve high sensitivity in the measurement of magnetic fields. SQUIPTs can provide phase control of the thermal conductivity at very low temperatures by modifying applied magnetic flux [1]. This article...
Electromagnetic response of a superconductor subject to incident electromagnetic wave is studied phenomenologically and within nonequilibrium equations of superconductivity.
A number of optical techniques have been investigated for implementation in the clinical practice for cancer detection in the gastrointestinal tract. The aim of those, so called “red-flag” modalities is to navigate and point out suspicious areas with pathological alterations in the tissue. Autofluorescence diagnostic is largely preferred, since it is patient friendly and cost-effective. The...
Due to growing demands for minituarization and small electronic devices, the production of novel composite material enhanced by the incorporation of nanomaterial fillers such as multiwall (MWCNT) and singlewall carbon nanotubes (SWCNT) is the subject of widespread research today. The investigations also shown that SWCNT explore better performance compared to MWCNT structures. One of the most...
Since the intrinsic Josephson effects in high-temperature superconductors were first investigated by R. Kleiner and P. Muller, various kinds of new phenomena related to the ¨effects have been found [1-5]. In this work, the emission of terahertz electromagnetic waves from an intrinsic Josephson junction array (IJJA) embedded in an LCR resonant circuit is studied theoretically. A bias current is...
The cell proliferation is a process that takes place through the cell cycle. Normally there is a balance between cell proliferation and death, when mutations that occur in ADN interrupt this process resulting in the birth of tumors. The spread of tumor diseases has led to the need to develop different methods for treating tumors. One of the methods of treating tumors is also through...
Here we consider a model in which the dwell time of the tunneling on a multi-barrier quantum structure based on monolayer graphene is computed. This quantum system is composed by $N$ barriers and $N-1$ wells, at zero temperature, in which the spin-orbit effects and the carrier-phonon interactions are absent. In addition, one assumes that the dimensions of the system in the $x-y$ plane are...
We study pair production processes from vacuum of scalar particles and fermions in the presence of an external Coulomb field on de Sitter expanding universe assuming that, the quantum fields are minimally coupled with gravity. Our study is done in the chart with spherical space coordinates and the produced particles are described by the spherical wave solutions of the field equations. In this...
In this paper we present our three different research activities set at the different EU labs. Due to lack of scientific tools at the premises of the University of Montenegro this was the way that allows us to be successful in taking role and responsibility towards addressing the questions of high priority within LGAD Research and Design activities as a member of RD50 CERN Collaboration....
Ultramarine has been for centuries one of the most highly prized pigments of all traditional artists’ materials, due to its durability, excellent color, and its intrinsic value. For the production of the blue pigment Ultramarine, the rare semiprecious stone Lapis Lazuli is used, which has been mined since ancient times in mines northeast of Afghanistan, making it difficult to transport to the...
We review tubes [1,2] consisting of magnetic dipolar particles as a model for magnetic nanostructures and show, in particular, how to obtain anti-ferromagnetic states. The tubular assemblies of magnetic particles can be realized with different thickness, length, and lattice structures. The universality of dipolar interaction concerning the length scale allows the realization of these systems...
As part of the Compact Muon Solenoid (CMS) experiment, the Electromagnetic CALorimeter (ECAL) detector control system (DCS) is preparing for major tests and upgrades of both software and hardware for the next long shutdown 3 (LS3). Interlocks of Cooling system, High Voltage (HV) and Low Voltage (LV) by the PLC system will be tested, as well as lowering the temperature at which the detector is...
The Self-emulsifying drug delivery systems (SEDDS) containing lipids, surfactants, and co-surfactants are a promising oral platform for drugs with problematic solubility and permeability. However, especially those systems representing a liquid phase may show some shortcomings, such as in vivo drug precipitation, limited lymphatic transport, and storage problems. These shortcomings can...
Timing is everything in biology – biological systems exchange information by controlling the spatio-temporal behavior of biological molecules, using dynamics to encode and decode information. Dynamic changes in the concentration of biological molecules are therefore an integral part of biological networks’ function and inadequate spatial distribution and temporal dynamics are characteristic of...
Due to its non-equilibrium character, non-thermal plasma is able to promote a large variety of chemical reactions and to produce numerous highly reactive species, and thus shows great potential for a number of applications.
This talk will present experimental results on some of these possible applications: (i) the degradation of organic compounds in water, in view of wastewater treatment;...
The aim of this study is to investigate the atmospheric air quality in Sofia during a 2-week period in the beginning of the first COVID-19 lockdown in March 2020. Observations of the aerosol distribution measured with two laser particle counters for PM2.5 and PM10 on clear sunny days (7 a.m. to 2 p.m.) at a site inside the built area near the bus stop Pliska on the Tsarigradsko shose during...
Methane is a powerful greenhouse biogas that plays a key role in several atmospheric environmental domains affecting the current enhancement of the greenhouse effect. It has been the cause of about 20% of the increased trapping of atmospheric infrared radiation during the past 200 years. In addition, it affects the oxidizing capacity of the atmosphere and, therefore, the lifetimes of other...
Fuzzy dark matter (FDM) is a rapidly growing area of research which aims to alleviate the shortcomings of the current leading cold dark matter (CDM) model. On large cosmic scales, FDM recreates the large scale structure generated by CDM simulations; the two diverge on smaller scales, where CDM suffers the most. Where CDM requires the addition of baryonic feedback and other physics, one of the...
In this paper we are presenting the numerical integration techniques applied in solving time delayed system. These systems are described by a type of differential equation in which the derivative of the unknown function at a certain time is given in terms of the values of the function at previous times. For the solution we are using the JiTCDDE package, a standalone Python implementation of...
Leukemia is the most common type of cancer found in children. It accounts for around 33% of all malignant diseases in pediatrics.
Differential scanning calorimetry DSC is a highly sensitive technique that measures temperature-induced conformation changes in proteins. As such, it is useful in measuring the exact values of concentration, conformation and interaction between proteins and other...
The aerosol particles in the atmosphere strongly influence the energy exchange between the Sun and the Earth’s atmosphere and surface. Thus, they could significantly impact multiple atmospheric phenomena, the climate, and the living conditions on the Earth. Also, the fine (submicron) fraction of the aerosol ensembles, the so called fine dust particles (FDP), may be especially harmful to the...
The constantly increasing demand for advanced products with improved performance and minimum thermal/energy/material waste alongside the fast emerging environmental challenges and the limited reliability and narrow life-cycle performance of old material systems greatly effect several areas of everyday life and economy. Thus, developing of advanced technological materials which satisfy the...
Background: Climate change is intertwined with excessive ambient temperatures. Humans’ adaptation to wide temperature changes varies greatly for unknown reasons. Methods: This study profits from a long-lasting heatwave event of the South-eastern Mediterranean: the july 1987 event. We studied a coastal (Piraeus) and a continental city (Athens). Mortality data were collected from the Piraeus...
Since their discovery in 1991, carbon nanotubes (CNTs) attract tremendous scientific interest. CNTs are nanodimensional objects, possessing excellent electrical, optical and thermal properties, large area, and a broad temperature range of thermal stability, making them promising for environmental, electrical, optical, biomedical, and etc. applications [1].
The main challenge to realize a...
Successive energy crises necessitate the use of renewable energy sources such as solar and wind, they can be properly complementary with other sources. We have presented solar and wind energies and their importance in the current status, their future in Albania, from the statistical point of view, including in terms of representative generation parameters.
It will be discussed for the...
Melittin as the major toxic component of the bee venom from Apis mellifera has previously been shown to be potent antibacterial agent with application in anticancer therapy. In the present study we analyze the action of melittin on biological systems using human erythrocytes and rat liver mitochondria as test systems. Alterations of lipid bilayer electrical resistance by melittin are probed by...
The flexoelectricity1 providing linear coupling is a phenomenon that takes place in liquid crystal systems. If the nematic liquid crystals (NLCs) molecules are slightly pear shaped and exhibit a longitudinal permanent dipole, like the cyanobiphenyls, an applied field not only orients the nematic director along the field direction but also causes a slight splay distortion of the director field....
Fe/Pt thin bilayers constitute a spintronic system for the prominence of the next generation of data processing, transfer, and storage devices 1–3. These magnetic heterostructures exhibit the ability to inject spin current through the interfaces via the spin pumping (SP) effect 4. However, only a few efforts investigate the magnetic properties of the systems through the interfacial morphology,...
The presented research aimed to study the microhardness, wettability as well as the surface roughness of organic spectacle lenses for everyday use, based on CR-39 (Poly(allyl diglycol carbonate) (PADC).
The modern spectacle lens's organic materials [1], like CR-39, are superior to the old mineral lenses in many aspects, but their major vulnerability to scratches and chemical substances...
Fitting potential energy curves (PEC) for diatomic molecules becomes a well-established routine confirmed empirically with numerous examples in the literature. One of the questions, which remains still open concerns the extrapolation properties of the potential functions. The experimental PECs virtually always are determined from a limited set of experimental data and this in turns limits the...
In the first studies of the generation of long-range quasi-non-diffracting Gauss-Bessel beams (GBBs) by creating and annihilating multi-charge optical vortices (OVs) [1-3], calibrated reflective liquid-crystal spatial light modulators are used. Because of their low damage threshold, they are not applicable with high-power laser beams. Vortex phase plates (VPs; phase plates which thickness is...
Minimally doubled fermions are a class of lattice fermions, which preserve exact chiral symmetry and are strictly local, details that make them very suitable for lattice simulations. Borici - Creutz fermions are one kind of minimally doubled fermions that have certain properties adaptable for lattice studies and simulations. In this work we present some of the lattice simulations made by using...
The mechanism of interaction between proteins and phospholipids in biological membranes has been shown to play an important role in the regulation of both the structural and dynamic properties of biomembranes and of the biological function of membrane proteins.
In an attempt to characterize the electrokinetic properties of human erythrocyte membranes and extrinsic proteins, the action of...
For the detection of celestial bodies near the Earth, called NEO bodies, Near Earth Object, among which are NEA asteroids, Near Earth Asteroids, several types of software and utilities have been created. This paper includes the way in which the image packets were processed, taken from the telescope, highlighting the characteristics of NEO bodies and how they were used in Astronomy, to obtain a...
Core/shell CdSe/CdS nanocrystals are one of the most important II–VI semiconductors with applications in solar cells, optoelectronics and electronic devices. CdSe / CdS nanocrystals are coated with thioglycolic acid to be water soluble. CdSe / CdS core-shell quantum dots have also been used, which reduce the toxicity of CdS nanocrystals on biological membranes. Semiconductor nanoparticles have...
Abstract. Power supply issues are more acute in isolated areas. Hybrid systems are becoming one of the most promising ways to meet the energy needs of microgrids. The proposed PV-wind- battery system consists of a PV system, a wind energy converter system and a battery system, which stores surplus energy from the PV and wind power systems, and uses this energy accumulated latter when the PV...
The ATLAS Muon Spectrometer upgrade [1] is designed to cope with expected increase of LHC luminosity and to include the advanced particle detector technologies. The MicroMesh Gaseous Structure detectors - the MicroMegas are used now as a large area tracking detector in the endcap parts of ATLAS Muon Spectrometer. The whole construction is built from sectors subdivided into detector modules....
Radon concentration measurements were performed at Technical College of Applied Sciences (TCAS) in Zrenjanin during summer, as part of the „Radon level measurements“ studies financed by the Provincial Secretariat for Higher Education and Scientific Research (the project is currently going on). The two lowest level rooms of the College building were examined, the basement and the groundfloor....
Microplastics (MPs) have globally been detected in aquatic and marine environments, which has raised scientific interests and public health concerns during the past decade. MPs are those polymeric particles with at least one dimension <5 mm [1]. They possess complex physicochemical properties that vary their mobility, bioavailability, and toxicity toward organisms and interactions with their...
Electricity is essential for human life, but growing demands for energy, high cost, limited fossil fuel resources, environmental pollution, and global warming through the greenhouse effect are the reason why renewable energy technologies, over about three recent decades, are seen as cost-effective and environmentally sustainable energy sources. Investments in the development of capacities of...
In the process of replacement of solid electrolytes, polymer electrolyte membranes have been gaining substantial attention in view of safety, non-toxic and economically viable. It is well acquaint that, till today lithium ion batteries are exhibiting reliable characteristic output properties. However, the continuous decrease of lithium resources lead to the development of better rechargeable...
The nickel-zinc electrochemical system is a promising candidate for alkaline batteries due to its low toxicity, high energy densities and power. Their main disadvantage is the solubility of the zinc electrode and the formation of dendrites during operation. Previous studies having used B(Pb)SCCO ceramic as additive in the Zn electrode mass proved its positive effect on improving the...
Acting as chemical signals neurotransmitters are expected to influence biological membranes' electrical properties, related to the transmission of electrical impulses and the interaction of cells with external electric fields. Closed membrane structures such as erythrocytes represent model system successfully exploited in the investigation of the electrical properties of biological membranes....
This study assesses the specific optimal tilt angle of a plane surface facing south to collect the maximal potential of solar energy. The study focuses on 5 different regions of Albania using several years of hourly solar radiation intensity data. The analysis shows the monthly variation of optimal tilt angle. The optimum tilt angle of the plain surface with horizon gradually increased from...
Recent occurrence of the pandemic revived the interest for germicidal ultraviolet (UV) lamps for disinfection. The use of the UV-C Light Emitting Diodes (LED) can deactivate microbes in air and water, but to achieve safe and successful disinfection of surfaces, careful and precisely defined usage is required that needs additional research. Commercially available UV-C LED lamp with the...
The modern Non-Intrusive Inspection Systems (NIIS) are a highly sophisticated machines that incorporate quality x-ray generation and detection capabilities, supported by state-of-the-art electronics, electro-mechanics, software algorithms and solutions. They are the backbone of air transportation security, and the commercial aviation is impossible without NIIS. Thus, the adequate real-time...
The environment presents a plethora of radiation sources, both of natural, but mainly of human origin. The need to evaluate the dose threshold for biological effects has led to the development of the area of dosimetry. Accidental dosimetry deals with the quantification of the dose absorbed after an accident. Studies focus on materials in the immediate vicinity of human. Materials which meet...
This study is an attempt to identify several tsunamigenic sources located offshore in the vicinity of Peloponnese Peninsula, Kefalonia and Lefkada. Ionian Sea is surrounded by major geological structures, like the Hellenic and the Calabrian subduction zones and in addition its lithosphere is submerging beneath Eurasian tectonic plate. These tectonic features are the main cause for devastating...
To achieve a good determination of the equivalent dose for occupational exposure workers from the whole body dosimeter an overall uncertainty associated with the measurement needs to be estimated. The work reported here is focused to estimate the absolute standard uncertainty that arises for Reader Calibration Factor (RFC), Element Correction Coefficient (ECC), and Zero Dose Reading. In this...
For an individual monitoring service is really important to provide accurate reports of the dose and to what extent the reported value is a good estimate of the true one. The process of determined the uncertainty which produces the best estimate of the quantity to be measured and may differ from the same quantity given by the instrument is an important one. This process can improve the result...
This talk will review different physical mechanisms involved in the emission of secondary radiations, with emphasis on terahertz waves, by laser-gas interactions. At moderate laser intensity, photocurrents can be exploited to perform a coherent terahertz spectroscopy of various crystals from air plasmas or to image tunneling electron wave packets from probing the polarization state of...
In the last twenty years Statistical Physics has contributed immensely to other scientific fields, mainly by the introduction of networks. The main reason has been the creation of the internet, which has been ubiquitous in daily life. The different structures of networks will be shown, together with their characteristics, with several different applications from real situations, which help us...
Several motors driving living cell alive have been recognized: electric motors, light motors, chemical motors, thermal motors, mechanical motors, etc. etc. Recently, the existence a new type of electro-mechanical motor has been recognized in cell membranes: bioflexoelectricity.
Phenomenon of bioflexoelectricity has been postulated, discovered, and investigated by us in the last 45 years....
I will discuss the problem of scale hierarchies in particle physics and cosmology and propose ways to address it. In particular I will present a framework of natural inflation within supergravity dubbed `inflation by supersymmetry breaking’. The main idea is to identify the inflaton with the superpartner of the goldstino, in the presence of a gauged R-symmetry that may contain the R-parity of...
Quantum computing (QC), based on principles of superposition, entanglement, and measurement of qubits, promises the advantage to surpass the performance of classical computing in cryptography, communication, and optimization problems, as well as in simulations of complex quantum system in physics and computation chemistry. Despite decades in development, fully coherent, fault-free universal...
In this talk I will review the very recent experiments conducted by my group on various quantum control techniques at some of the open-access IBM quantum processors. I particular, I will show results on quantum control by composite pulses, quantum control by polychromatic pulse trains, quantum sensing of small frequency shifts, tuning the parameters of the quantum computer, dynamical...
A project for the establishment of an international intergovernmental scientific organization in the region of South East Europe (European Institute for Sustainable Technologies - SEEIIST) is under way. The research infrastructure will include a powerful next generation accelerator that will provide proton and ion beams for tumor treatment and biomedical research. The center will comprise...
In this lecture, we will give an overview of some of the latest results related to superconductors under the influence of time-varying electric and magnetic fields.
Study of the effect of inorganic nanoparticles on the human cells has been intensified due to emerging applications of such nanoparticles in diagnostics, drug delivery, medical therapy, etc [1]. Several classes of nanoparticles have been proposed for use in cancer therapy as they were demonstrated to decrease cancer cells viability in the scientific studies. Nanoparticles that have so called...
Albania is a small country in the western Balkans with a population of 2.8 million. The health system has undergone major transformations especially in the last 10 years especially with the involvement of the private sector in health services. Despite the improvements made, the global pandemic COVID-19 19 found the Albanian health system unprepared, highlighting the problems and its...
The recent discovery of the NS+ cation in the interstellar medium1 triggered the interest in the study of its collision with electrons. In this complex process, the electron can be captured into NS Rydberg-bound states predissociated by Feshbach resonances of this latter molecule. These both types of states have been calculated within the Born-Oppenheimer approximation using a variationa...
The Swampland is defined as the set of consistent Quantum Field Theories that cannot be coupled to Quantum Gravity. The goal of the Swampland is to find or to conjecture, based on the intuition gained from String Theory, general principles that a field theory coupled to quantum gravity should respect. One example is the "gravity as the weakest force" (or "weak-gravity conjecture").
I will...
The project examines the current state-of-the-art and use of radiation therapy in treatment patients with cancer. Through it different treatments are explained with special emphasis on those currently accessible in Montenegro and South - Eastern Europe (SEE). Both, advantages and disadvantages of each kind of treatment were considered. Especially, detailed analysis of hadron therapy (HT) is...
Non-sequential double ionization (NSDI) is a strong-field atomic process in which two electrons simultaneously leave atom irradiated by an intense laser pulse.$^1$ This process has been described successfully by the three-step (TS) model. The first step of this model is the process of tunneling an atomic electron through the barrier which is formed by combining the atomic potential with the...
We present rogue wave solutions to the standard cubic nonlinear Schrődinger equation that models many propagation phenomena in nonlinear optics. We propose the method of mode pruning for suppressing the modulation instability of rogue waves. We point to instances when rogue waves appear as numerical artefacts, due to inadequate numerical treatment of modulation instability and homoclinic chaos...
Providing effective lubrication at high temperatures/pressures and in oxidative environments is relevant for various industrial applications, such as turbomachinery and cutting tools [1,2]. Promising solutions for such conditions are oxidation-resistant hard coatings consisting of binary or ternary films (Cr-N, Ti-N, Cr-Al-N, Ti-Al-N) doped with an additional element which can diffuse to the...
In this contribution we will review a wide variety of LGAD applications ranging from the timing measurements for HL-LHC (HGTD for ATLAS and MIP Timing detector for CMS) to reaction time detector for experiments utilizing proton and pion beams with the High Acceptance Di-Electron Spectrometer (HADES), at GSI Darmstadt, Germany, and to beam structure monitoring for medical applications...
The experimental search of non-conventional effects predicted by bottom-up approaches and theoretical models of quantum gravity is a quite recent field of research. Generically, it requires to consider probes of very high-energy and amplification mechanisms, conditions which are fulfilled by the propagation of the cosmic messengers. Advances in multi-messenger astronomy during the last decade...
Monte Carlo algorithms often require large computing resources, primarily in the form of processing time. Knowledge of the underlying principles governing the simulated problem under specific circumstances allows the use of certain variance reduction methods. This work introduces a novel approach to variance reduction based on the partial axial symmetry of the clinical accelerator.
The...
We study the first order infrared behavior of "tame" hyperbolizable two-field cosmological models, defined as those classical two-field models whose scalar manifold is a connected, oriented and topologically finite hyperbolizable Riemann surface and whose scalar potential admits a positive and Morse extension to its end compactification. We achieve this by determining the universal forms of...
Antimicrobial peptides (AMPs) are a diverse class of short proteins, that are a key element of the nonspecific innate immunity in most organisms, displaying a wide range of antimicrobial, antifungal, antiviral and even anticancer effects. Lately, AMPs have attracted great research interest in the context of strategies to combat multi-drug resistant bacterial infections. AMPs come in nature in...
The flattening filter is a piece of metal with conical shaped mounted within the treatment head of a linear accelerator, used to produce a flat, uniform beam of X-rays from the forward-peaked distribution exiting the target. They have been used since the introduction of the linac in the 1950’s, however, there are still several unresolved issues surrounding their use. The photon scatter and...
We introduce the notion of global and local thermodynamic equilibrium for any thermal system with well-defined first law. Our approach relies only on few key concepts, namely: Legendre transformation, Hessian matrices, Nambu brackets and thermodynamic curvature. In the extremal point, every convex (concave) potential must be in its global minimum (maximum). This allows one to impose standard...
Many radionuclides have a history as a source for brachytherapy, but today only a few are commonly used. They are characterized by the rate at which their strength decays (half-life), by how much radioactivity can be obtained for a given mass of the radioactive source (specific activity) and by the energies and types of the radiation particles that are emitted from the source (energy spectrum)...
Cosmological inflation provides solutions to some problems in standard cosmology. Many different scenarios of inflation have been proposed. The generally accepted and the most commonly used approach is that the inflationary phase can be described by a single scalar field. One of the interesting possible mechanisms for inflation is based on the dynamics driven by the tachyon field $\theta$ [1,...
A nonlocal gravity model
$ S = \frac 1{16\pi G} \int (R-2\Lambda+(R-4\Lambda)\mathcal{F}(\Box)(R-4\Lambda))\sqrt{-g} \mathrm d^4 x $
was recently introduced, and two exact cosmological solutions in flat space were presented.
One solution has similar properties to an interplay between the radiation and the dark energy, while the other one is a nonsingular time symmetric bounce. In this...
In the context of the spontaneously broken scale-invariant nonlinear electrodynamic introduced by Guendlmann et al with a magnetic dominance feature, we construct a thin-shell wormhole. The surface tension of the TSW is zero in static configuration implying the exotic matter present at the throat is a cloud of exotic dust. We apply the small-velocity perturbation as well as the radial linear...
The LISA (Laser Interferometric Space Antenna) is an ESA/NASA space mission with the aim to observe gravitational waves in space at lower frequencies than it is possible with Earth bounded detectors.
It will thus be able to observe, e.g., the coalescence of supermassive black holes, which are present in the galactic centres.
I will describe the scientific objectives of the mission and...
A first description of this phenomenon, as well as its application in practice was made by acad. Boris Lazarenko. Based on what he and his colleagues presented, new processes for electro-physical processing of materials were developed. This paper, based on the analysis of the literature, as well as on our own experimental investigations and findings, shows that the proper erosion of metals is...
Nuclear power, which accounts for about 10 percent of the world’s electricity supply, is currently the only technology with a secure base-load electricity supply and no greenhouse gas emissions that has the potential to expand at a large scale and effectively replace fossil fuels. However, after the 2011 Fukushima accident some countries, particularly in Europe, decided to slow down further...
I will present recent progress in changing the way Physics is taught at Ovidius University of Constanta, Romania, following two projects the university has been involved in: Restart4Edu, an Erasmus+ project focusing on Project-Based Learning and a national project preparing the trainers for master's programs in education. I will illustrate how we applied our approach, based on backward...
Quasi-two-dimensional materials, known for their easy exfoliation to a monolayer and unique optical and transport properties are promising candidates for nanospinctronics and nanoelectronics. Experimental confirmation of magnetic ordering persisting to a monolayer in these complex systems in 2017 did not only widen up the area of their potential application, but also opened up a completely new...
We are concerned with completely integrable Hamiltonian systems and generalized action-angle coordinates in the setting of contact geometry. We investigate the deformations of the Sasaki--Einstein structures, keeping the Reeb vector field fixed, but changing the contact form. We examine the modifications of the action-angle coordinates by the Sasaki--Ricci flow. We then pass to the particular...
