269 results match your criteria: "Institute of Physics Belgrade[Affiliation]"

We disclose a new class of patterns, called patched patterns, in arrays of non-locally coupled excitable units with attractive and repulsive interactions. The self-organization process involves the formation of two types of patches, majority and minority ones, characterized by uniform average spiking frequencies. Patched patterns may be temporally periodic, quasiperiodic, or chaotic, whereby chaotic patterns may further develop interfaces comprised of units with average frequencies in between those of majority and minority patches.

View Article and Find Full Text PDF

It is generally accepted that the dynamical mean field theory gives a good solution of the Holstein model, but only in dimensions greater than two. Here, we show that this theory, 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, even in one dimension. To establish this, we make a detailed comparison with the spectral functions that we obtain using the newly developed momentum-space numerically exact hierarchical equations of motion method, which yields electronic correlation functions directly in real time.

View Article and Find Full Text PDF

Optimization of the Growth Process of Double Perovskite PrNiMnO Epitaxial Thin Films by RF Sputtering.

Materials (Basel)

July 2022

Institut de Ciència de Materials de Barcelona, Consejo Superior de Investigaciones Científicas (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Spain.

Epitaxial thin films of PrNiMnO (PNMO) double perovskite were grown on (001)-oriented SrTiO substrates by RF magnetron sputtering. The influence of the growth parameters (oxygen pressure, substrate temperature, and annealing treatments) on the structural, magnetic and transport properties, and stoichiometry of the films was thoroughly investigated. It is found that high-quality epitaxial, insulating, and ferromagnetic PNMO thin films can only be obtained in a narrow deposition parameter window.

View Article and Find Full Text PDF

Various mathematical frameworks play an essential role in understanding the economic systems and the emergence of crises in them. Understanding the relation between the structure of connections between the system's constituents and the emergence of a crisis is of great importance. In this paper, we propose a novel method for the inference of economic systems' structures based on complex networks theory utilizing the time series of prices.

View Article and Find Full Text PDF

Suppression of Superconductivity and Nematic Order in FeSeS (0 ≤ ≤ 1; ≤ 0.1) Crystals by Anion Height Disorder.

Inorg Chem

July 2022

Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, United States.

Connections between crystal chemistry and critical temperature have been in the focus of superconductivity, one of the most widely studied phenomena in physics, chemistry, and materials science alike. In most Fe-based superconductors, materials chemistry and physics conspire so that correlates with the average anion height above the Fe plane, i.e.

View Article and Find Full Text PDF

Nature of Dynamic Friction in a Humid Hydrophobic Nanocontact.

ACS Nano

July 2022

Scientific Computing Laboratory, Center for the Study of Complex Systems, Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia.

The physics of dynamic friction on water molecule contaminated surfaces is still poorly understood. In line with the growing interest in hydrophobic contact for industrial applications, this paper focuses on friction mechanisms in such interfaces. As a commonly used material, contact with graphite is considered in a twin-fold approach based on experimental investigations using the circular mode atomic force microscopy technique combined with molecular dynamic simulations.

View Article and Find Full Text PDF

Novel wide spectrum light absorber heterostructures based on hBN/In(Ga)Te.

J Phys Condens Matter

June 2022

Center for Solid State Physics and New Materials, Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia.

Two-dimensional group III monochalcogenides have recently attracted quite attention for their wide spectrum of optical and electric properties, being promising candidates for optoelectronic and novel electrical applications. However, in their pristine form they are extremely sensitive and vulnerable to oxygen in air and need good mechanical protection and passivization. In this work we modeled and studied two newly designed van der Waals (vdW) heterostructures based on layer of hexagonal boron nitride (hBN) and GaTe or InTe monolayer.

View Article and Find Full Text PDF

A Single-Cell Raman Spectroscopy Analysis of Bone Marrow Mesenchymal Stem/Stromal Cells to Identify Inter-Individual Diversity.

Int J Mol Sci

April 2022

Group for Hematology and Stem Cells, Institute for Medical Research, National Institute of Republic of Serbia, University of Belgrade, 11129 Belgrade, Serbia.

The heterogeneity of stem cells represents the main challenge in regenerative medicine development. This issue is particularly pronounced when it comes to the use of primary mesenchymal stem/stromal cells (MSCs) due to a lack of identification markers. Considering the need for additional approaches in MSCs characterization, we applied Raman spectroscopy to investigate inter-individual differences between bone marrow MSCs (BM-MSCs).

View Article and Find Full Text PDF

Four distinct tungsten suboxide (WO) nanomaterials were synthesized via chemical vapour transport reaction and the role of their crystal structures on the optical properties was studied. These materials grow either as thin, quasi-2D crystals with the WOformula (in shape of platelets or nanotiles), or as nanowires (WO, WO). For the quasi-2D materials, the appearance of defect states gives rise to two indirect absorption edges.

View Article and Find Full Text PDF

The increase in the resistivity with decreasing temperature followed by a drop by more than one order of magnitude is observed on the metallic side near the zero-magnetic-field metal-insulator transition in a strongly interacting two-dimensional electron system in ultra-clean SiGe/Si/SiGe quantum wells. We find that the temperature [Formula: see text], at which the resistivity exhibits a maximum, is close to the renormalized Fermi temperature. However, rather than increasing along with the Fermi temperature, the value [Formula: see text] decreases appreciably for spinless electrons in spin-polarizing (parallel) magnetic fields.

View Article and Find Full Text PDF

Distinct fatty acid redistribution and textural changes in the brain tissue upon the static magnetic field exposure.

Environ Toxicol Pharmacol

May 2022

Department of Pathological Physiology, Faculty of Medicine, University of Belgrade, Dr. Subotića 9, 11000 Belgrade, Serbia. Electronic address:

We observed different outcomes upon the subacute exposure to the 128 mT highly homogeneous static magnetic field (SMF) when its orientation was (i) aligned with the vertical component of the geomagnetic field; (ii) in the opposite direction. We employed the fatty acids (FA) composition and digital image analyses (DIA) to provide insights into the underlying processes and examine the possible weak SMF effects. Swiss-Webster male mice were whole-body exposed for 1 h/day over five days.

View Article and Find Full Text PDF

We discover the mechanisms of emergence and the link between two types of symmetry-broken states, the unbalanced periodic two-cluster states and solitary states, in coupled excitable systems with attractive and repulsive interactions. The prevalent solitary states in non-locally coupled arrays, whose self-organization is based on successive (order preserving) spiking of units, derive their dynamical features from the corresponding unbalanced cluster states in globally coupled networks. Apart from the states with successive spiking, we also find cluster and solitary states where the interplay of excitability and local multiscale dynamics gives rise to so-called leap-frog activity patterns with an alternating order of spiking between the units.

View Article and Find Full Text PDF

We report the results of the measurements and calculations of the absolute differential elastic electron scattering cross-sections (DCSs) from sevoflurane molecule (CHFO). The experimental absolute DCSs for elastic electron scattering were obtained for the incident electron energies from 50 eV to 300 eV, and for scattering angles from 25° to 125° using a crossed electron/target beams setup and the relative flow technique for calibration to the absolute scale. For the calculations, we have used the IAM-SCAR+I method (independent atom model (IAM) applying the screened additivity rule (SCAR) with interference terms included (I)).

View Article and Find Full Text PDF

Correlation between morphology and local mechanical and electrical properties of van der Waals heterostructures.

Nanotechnology

January 2022

Center of Excellence for Advanced Materials and Sensing Devices, Institute of Physics, Bijenička 46, 10000, Zagreb, Croatia.

Article Synopsis
  • The performance of van der Waals (vdW) heterostructures is heavily influenced by the quality of their interfaces, where flaws like bubbles and intercalated layers (ILs) can trap contaminants.
  • These imperfections lead to softer areas with higher friction, reducing electrical current and contact potential due to poor charge transfer between layers.
  • To improve contact between the MoS and WS layers, techniques like localized flattening with an atomic force microscopy (AFM) tip were used, resulting in enhanced electrical conductivity and increased contact potential difference.
View Article and Find Full Text PDF

Search for topological defect dark matter with a global network of optical magnetometers.

Nat Phys

December 2021

State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Electronics, and Center for Quantum Information Technology, Peking University, Beijing, China.

Article Synopsis
  • - Ultralight bosons like axion-like particles are considered strong contenders for dark matter and can create stable structures called topological defects that cluster dark matter in small areas throughout the galaxy.
  • - The study utilized a global network of optical magnetometers to search for transient signals from domain walls created by these axion-like particles.
  • - After analyzing a month of data, the researchers found no significant signals, which helps to limit the theoretical possibilities of dark matter involving these particles.
View Article and Find Full Text PDF

Magnesium aluminate and other alumina-based spinels attract attention due to their high hardness, high mechanical strength, and low dielectric constant. MgAlO was produced by a solid-state reaction between MgO and α-AlO powders. Mechanical activation for 30 min in a planetary ball mill was used to increase the reactivity of powders.

View Article and Find Full Text PDF

Self-organized coherence-incoherence patterns, called chimera states, have first been reported in systems of Kuramoto oscillators. For coupled excitable units, similar patterns where coherent units are at rest are called bump states. Here, we study bumps in an array of active rotators coupled by nonlocal attraction and global repulsion.

View Article and Find Full Text PDF

Among the polycyclic aromatic hydrocarbons (PAH), benzo[a]pyrene (B[a]P) has been considered more relevant than other species when estimating the potential exposure-related health effects and has been recognized as a marker of carcinogenic potency of air pollutant mixture. The current understanding of the factors which govern non-linear behavior of B[a]P and associated pollutants and environmental processes is insufficient and further research has to rely on the advanced analytical approach which averts the assumptions and avoids simplifications required by linear modeling methods. For the purpose of this study, we employed eXtreme Gradient Boosting (XGBoost), SHapley Additive exPlanations (SHAP) attribution method, and SHAP value fuzzy clustering to investigate the concentrations of inorganic gaseous pollutants, radon, PM and particle constituents including trace metals, ions, 16 US EPA priority PM-bound PAHs and 31 meteorological variables, as key factors which shape indoor and outdoor PM-bound B[a]P distribution in a university building located in the urban area of Belgrade (Serbia).

View Article and Find Full Text PDF

Understanding variations in the severity of infectious diseases is essential for planning proper mitigation strategies. Determinants of COVID-19 clinical severity are commonly assessed by transverse or longitudinal studies of the fatality counts. However, the fatality counts depend both on disease clinical severity and transmissibility, as more infected also lead to more deaths.

View Article and Find Full Text PDF

Using the dynamical mean field theory we investigate the magnetic field dependence of dc conductivity in the Hubbard model on the square lattice, fully taking into account the orbital effects of the field introduced via the Peierls substitution. In addition to the conventional Shubnikov-de Haas quantum oscillations, associated with the coherent cyclotron motion of quasiparticles and the presence of a well-defined Fermi surface, we find an additional oscillatory component with a higher frequency that corresponds to the total area of the Brillouin zone. These paradigm-breaking oscillations appear at elevated temperature.

View Article and Find Full Text PDF

Psychological bias towards, or away from, prior measurements or theory predictions is an intrinsic threat to any data analysis. While various methods can be used to try to avoid such a bias, actively avoiding looking at the result, only data blinding is a traceable and trustworthy method that can circumvent the bias and convince a public audience that there is not even an accidental psychological bias. Data blinding is nowadays a standard practice in particle physics, but it is particularly difficult for experiments searching for the neutron electric dipole moment (nEDM), as several cross measurements, in particular of the magnetic field, create a self-consistent network into which it is hard to inject a false signal.

View Article and Find Full Text PDF

The design of the n2EDM experiment: nEDM Collaboration.

Eur Phys J C Part Fields

June 2021

Paul Scherrer Institut (PSI), 5232 Villigen, Switzerland.

We present the design of a next-generation experiment, n2EDM, currently under construction at the ultracold neutron source at the Paul Scherrer Institute (PSI) with the aim of carrying out a high-precision search for an electric dipole moment of the neutron. The project builds on experience gained with the previous apparatus operated at PSI until 2017, and is expected to deliver an order of magnitude better sensitivity with provision for further substantial improvements. An overview is of the experimental method and setup is given, the sensitivity requirements for the apparatus are derived, and its technical design is described.

View Article and Find Full Text PDF

Microscopic examination of stained peripheral blood smears is, nowadays, an indispensable tool in the evaluation of patients with hematological and non-hematological diseases. While a rapid automated quantification of the regular blood cells is available, recognition and counting of immature white blood cells (WBC) still relies mostly on the microscopic examination of blood smears by an experienced observer. Recently, there are efforts to improve the prediction by various machine learning approaches.

View Article and Find Full Text PDF

Identifying the main environmental drivers of SARS-CoV-2 transmissibility in the population is crucial for understanding current and potential future outbursts of COVID-19 and other infectious diseases. To address this problem, we concentrate on the basic reproduction number , which is not sensitive to testing coverage and represents transmissibility in an absence of social distancing and in a completely susceptible population. While many variables may potentially influence , a high correlation between these variables may obscure the result interpretation.

View Article and Find Full Text PDF

Benefits and risks of the fish consumption should be assessed to balance the ingestion of healthy omega-3 fatty acids and adverse chemicals. Persistent organic pollutants-POPs (organochlorine pesticides-OCPs and polychlorinated biphenyls-PCB), macro- and micro-elements and fatty acid contents were determined in six fish species from the Adriatic Sea to assess health risks for consumers (worst-case scenario, diseases development risks and benefit-risk). 16 element, 24 POPs and 14 fatty acid contents were determined in six pelagic species which can be used in human diet.

View Article and Find Full Text PDF