Volume 74, Number 3, 2022
IN MEMORIAM: DUMITRU MAZILU (25 July 1943 - 6 April 2022)

Rom. Rep. Phys. 74, 001 (2022)
Article no. 001: PDF 
 
THEORETICAL, MATHEMATICAL, AND COMPUTATIONAL PHYSICS
 
New integrable (3+1)-dimensional Mikhailov-Novikov-Wang equation: multiple soliton solutions and other physical solutions
ABDUL-MAJID WAZWAZ, WEDAD ALBALAWI, S. A. EL-TANTAWY
Rom. Rep. Phys. 74, 114 (2022)
Abstract. The current work aims to present an extended integrable (3+1)-dimensional Mikhailov-Novikov-Wang equation. The complete integrability of this extended equation via using Painlevé analysis is studied. We show that the new additional terms to the standard (1+1)-dimensional Mikhailov-Novikov-Wang equation do not terminate its complete integrability. A variety of multiple soliton solutions, by imposing appropriate parameter selections, is obtained by using the simplified Hirota's scheme. We provide other solutions that include rational, periodic, and exponential ones. The extended Mikhailov-Novikov-Wang equation provides new insights of the relation between water waves and integrability by imposing appropriate parameters.
Article no. 114: PDF 
Dynamics of dark-dark solitons and breathers in the two-component nonlinear Schrödinger equations coupled to Boussinesq equation
XIANG CHEN, JIGUANG RAO
Rom. Rep. Phys. 74, 115 (2021)
Abstract. General higher-order dark-dark solitons and breathers in the two-component nonlinear Schrödinger equations coupled to Boussinesq (2NLS-Boussinesq) equation are derived by the bilinear KP-hierarchy reduction method, and are given in terms of determinants. These dark-dark solitons only show elastic collisions and the two dark-dark solitons can form bound states. In contrast to the dark-dark solitons in 2NLS equation, which only admits a stationary bound state, the two dark-dark solitons in the 2NLS-Boussinesq equation possesses more bound sates. The dynamics of breathers are also investigated, and they become the homoclinic orbits under particular parametric restrictions.
Article no. 115: PDF 
On the Davey-Stewartson hierarchy: construction by two scalar pseudo-differential operators and compatibility for infinite many flows
G. YI, X. LIAO
Rom. Rep. Phys. 74, 116 (2022)
Abstract. The infinite many symmetries of Davey-Stewartson (DS) system are closely connected to the integrable deformations of surfaces in a four-dimensional space. In this paper, we give a direct algorithm to construct the expression of the DS hierarchy by two scalar pseudo-differential operators involving partial derivatives.
Article no. 116: PDF 
 
ATOMIC, MOLECULAR, AND NUCLEAR PHYSICS
 
Development of an external ion beam setup at the 3MV Tandetron accelerator at IFIN-HH
A. ROTARU, M. STRATICIUC, A. STATE, I. BURDUCEA, V. RUNCEANU, D. IANCU, R. F. ANDREI, D. GHIŢĂ
Rom. Rep. Phys. 74, 202 (2022)
Abstract. We describe our progress in designing an experimental system to enable in-air Ion Beam Analysis (IBA) at the 3 MV Tandetron accelerator at IFIN-HH. The main applications will be investigations of objects of cultural heritage using external ion beams and analysis of materials that are not compatible with high vacuum. We discuss the technical solution and its implementation, together with the experimental results that demonstrates this new setup.
Article no. 202: PDF 
Design studies of a 200 MeV Thomson parabola spectrometer for the use at the 10 PW laser system at ELI-NP
L. TUDOR, S. KISYOV, C. A. UR, D. DORIA, F. NEGOITA, D. STUTMAN, F. ROTARU, D. SANGWAN, M. V. TATARU, K. M. SPOHR
Rom. Rep. Phys. 74, 203 (2022)
Abstract. Design and shielding requirements for the 200 MeV Thomson Parabola spectrometer to be built for use at the 10 PW beamline at the Extreme Light Infrastructure (ELI-NP) are shown. Simulations were undertaken using the GEANT4 toolkit to estimate the signal-to-noise ratio S/N for the detector facilitating a scintillator detection screen. The energy deposition, ΔEp, of laser-accelerated protons with Ep = 200 MeV in the scintillator was compared to the corresponding value of ΔEγ induced by the hard X-ray radiation which emerges from the γ-flash triggered by the initial laser-target interaction.
Article no. 203: PDF 
 
OPTICS AND PHOTONICS, PLASMAS, LASER AND BEAM PHYSICS
 
Effects of the different laser beam profiles on the tunneling ionization with Coulomb correction included
TATJANA B. MILADINOVIĆ, MIRKO M. RADULOVIĆ, JASNA M. STEVANOVIĆ
Rom. Rep. Phys. 74, 406 (2022)
Abstract. The aim of this paper was to theoretically investigate the applicability of lasers with 10.6 µm and 800 nm wavelength and different spatial distributions on tunneling ionization of alkali atoms. It includes a comparative study of ionization rate with two expressions for initial non-zero momentum of ejected electron. Results show that ionization rates for non-phased and LG(0,1)* spiral-phased linearly polarized laser beams are sensitive to the type of laser, cause different exit points, reach maxima on different intensity values, and have the dissimilar manner of decrease.
Article no. 406: PDF 
 
CONDENSED AND SOFT MATTER PHYSICS
 
Dielectric and electric properties of novel core-shell nanocomposite: SrFe12O19-BNT-BT
S.G. GRECULEASA, C. COMANESCU, M. CIOANGHER
Rom. Rep. Phys. 74, 504 (2022)
Abstract. The dielectric and electric properties of a core-shell SrFe12O19-BNT-BT nanocomposite were explored in this study. The desired composition and the existence of the magnetoplumbite SrFe12O19 and perovskite BNT-BT structures were verified by X-ray diffraction. The dielectric constant values approached the case of BNT-BT due to the small amount of hexaferrite content. The electric properties were also derived.
Article no. 504: PDF 
 
BIOPHYSICS AND MEDICAL PHYSICS
 
Dosimetry analysis on IMRT-VMAT technique in hippocampal sparing whole brain irradiation with simultaneous integrated boost for metastatic cancer
A. ANICA, M. D. SUDITU, A. D. OLĂRESCU, E. L. MILITARU, C. M. MIU, A. M. OPREA, D. L. STĂNCULEANU
Rom. Rep. Phys. 74, 603 (2022)
Abstract. Advanced radiotherapy treatment techniques limit the cognitive morbidity associated with whole-brain radiotherapy (WBRT) for brain metastasis through avoidance of hippocampal structures. However, achieving durable intracranial control remains challenging. We conducted a single-institution single-arm phase I trial of hippocampalsparing whole brain irradiation with simultaneous integrated boost (HSIB-WBRT) to metastatic deposits in adult patients with brain metastasis. Radiation therapy consisted in intensity-modulated radiation therapy delivering 30 Gy in 10 fractions over 2 weeks to the whole brain with a simultaneous integrated boost of 40 Gy in 10 fractions to metastatic lesions. Hippocampal regions were limited to a maximum dose of 17 Gy. Patients were treated using an Elekta VERSA HD equipped with the AgilityTM 160 multileaf collimator for high-speed. A total of 29 patients, median age 54 years (interquartile range, 50-61), were enrolled. Mean dose for hippocampus was 9 Gy when the boost was located at a distance greater than 1 cm from hippocampus avoid region and the maximum dose was 16 Gy. For patients with boost at a distance lesser than 1 cm from hippocampus avoid region, the dose obtained could not met the dose constraints for hippocampus. Hippocampal-sparing whole brain irradiation with simultaneous integrated boost for metastatic cancer is feasible when the boost is administered at a distance greater than 1 cm from hippocampus avoid region. For patients with metastatic lesions at a distance lesser than 1 cm from hippocampus avoid region, the dose constraints could not be met.
Article no. 603: PDF 
Eye tumor tissues imaging with white ligt diffraction phase microscopy
V. NASTASA, ADRIANA SMARANDACHE, RUXANDRA A. PIRVULESCU, I. R. ANDREI, G. SIMION, G. POPESCU, M. L. PASCU
Rom. Rep. Phys. 74, 604 (2022)
Abstract. In the current context of histopathology, where the gold standard remains the manual investigation of stained tissues, development of new sensitive methods for early diagnosis of diseases is necessary. White light diffraction phase microscopy, may answer this challenge by detecting very small variations of refractive indexes in biological specimens. Eye tissue samples images were acquired by conventional microscopy, and by white light diffraction phase microscopy technique. A comparative histological analysis was performed to evidence the characteristics of biological structures. Quantitative images with increased contrast of some cellular structures were obtained using white light diffraction phase microscopy.
Article no. 604: PDF 
 
ENVIRONMENTAL AND EARTH PHYSICS
 
Seismic moment tensor solutions for geophysical mapping of the Philippine sea basin by GMT
POLINA LEMENKOVA
Rom. Rep. Phys. 74, 707 (2022)
Abstract. This paper presents a GMT scripting technique for mapping seismic moment tensor solutions. The underlying geophysical properties and settings of the Philippine Sea Plate (PSP) situated on the margins of the Pacific Ocean are analysed. Active volcanism and high seismicity of this region located along the margins of the Philippine Sea Basin (PSB) results in a series of earthquake events caused by geodynamic processes of tectonic plate subduction. The proposed console-based framework of cartographic workflow is designed to perform mapping of the earthquake events using Generic Mapping Tools (GMT) modules, to analyse seismic setting through visualisation of the geophysical dataset. The materials include General Bathymetric Chart of the Oceans (GEBCO), Centroid Moment Tensor (CMT) and International Seismological Centre (ISC) seismic data. Technically, the algorithm of mapping by GMT consists in a consecutive use of modules used in a script run from a command line: 'psmeca', 'psvelo', 'img2grd', 'grdtrack', 'grdimage'. The GMT functionality is illustrated by the key snippets of code. The path to the full codes is provided with a link to the author's GitHub repository for technical repeatability. Furthermore, the algorithm of GMT enabled to visualise CMT solutions for shallow depth earthquakes of Mw < 10 along the PSB margins from 1976 to 2010. Thus, the paper also demonstrated and presented the performance of the GMT on a geophysical dataset that features complete earthquakes data along the zone of tectonic plate subduction from the Global CMT Project. In both technical and geophysical cases, this approach of GMT-based mapping presents cartographic workflow better than state-of-the-art traditional GIS programs through increased automation of the cartographic workflow. The study contributed to the development of methods of geophysical and seismic mapping using GMT scripting toolset by visualising focal mechanisms and seismic moment tensor solutions.
Article no. 707: PDF 
Spectral characteristics of the seismic response from local recordings. Application to urban areas.
B. F. APOSTOL, C. O. CIOFLAN, A. MARMUREANU
Rom. Rep. Phys. 74, 708 (2022)
Abstract. The seismic response recorded at two sites is analyzed, as it results from strong motion generated by Vrancea intermediate-depth seismic source. Three strongest seismic events generated by the Vrancea intermediate-depth seismic zone in the last five decades are chosen for this purpose. The evaluation is made for two areas of interest, as revealed by the spectral features influenced by the geological deposits under seismic excitation. The results are shown as response spectra at Bucharest-INCERC and Cernavoda downtown seismic stations for three strong earthquakes and other three weaker, collocated as pairs. The manner in which the seismic response for a broader range of magnitudes is affected by the specificity of each site is investigated. The shift of the predominant period is large at INCERC station, where high values are encountered, disposed of on a broader range. At this site, spectral ratios for each of the three pairs of seismic response spectra are performed, in order to showe the seismic source influence on local effects. The observed local amplification in correspondence to the site characteristics is highlighted.
Article no. 708: PDF 
Determining the seasonal signal and noise in different CORS GNSS network from Romania
S. NISTOR, N.-S. SUBA, E.I. NASTASE, A. MUNTEAN
Rom. Rep. Phys. 74, 709 (2022)
Abstract. Daily coordinate time series from Global Navigation Satellite System (GNSS) exhibits important seasonal signals for the horizontal and vertical component. These essential signals must be estimated because they play a very important role in the final estimates, especially for site velocity. The article is analyzing in terms of seasonality and noise, 152 stations from 5 different Continuously Operating Reference Stations (CORS) that have GNSS stations in Romania. The importance of this study is twofold: the first one is given by the relevance of separating various geophysical signals which truthfully reflect critical crustal deformations or the effect of different surface mass loadings, and second, is to compare relatively close stations which are part of two different CORS networks. Due to the fact that the underlying noise of the GNSS station is related to the seasonal signal, using Maximum Likelihood Estimation (MLE) we are able to estimate both seasonal signals, the type of noise and its amplitude for the Romanian GNSS CORS network. The results of the noise analysis show that at low frequencies we have spectral indices that varies between -2 and 0, which reveals that the dominant type of noise is flicker and random noise.
Article no. 709: PDF 
 
APPLIED AND INTERDISCIPLINARY PHYSICS
 
Bio-decontamination and surface modification of polymers by corona discharge for food industry
E.C. STANCU, A. QUADE, F. HEMPEL
Rom. Rep. Phys. 74, 803 (2022)
Abstract. In this study, the bio-decontamination of PU and PVC is performed with corona discharge by using a scanning procedure. By increasing the number of scans the plasma treatment becomes more effective against of E. coli and S. aureus. Changes in polymer surface properties after plasma treatment were also considered.
Article no. 803: PDF 
 
PHYSICS EDUCATION
 
Using a remote lab for electrolysis experiment as part of renewable energy courses
SANDA VOINEA, ADRIANA BALAN, R. MORGAN GREENE, LAURENTIU L. ANTON, RADU TIRCA, DANIEL COSTACHE, VICTOR T. DUMITRU
Rom. Rep. Phys. 74, 904 (2022)
Abstract. According to the European Renewable Energy Directive, by 2030, renewable energy must account for 32% of energy production. This goal requires specialists with interdisciplinary training in the field of renewable energy sources, who can integrate the concepts of sustainability and the zero carbon world into new technological solutions and develop new green energy policies. In this context, comprehensive, detailed and innovative training for green energy specialists is needed. This paper presents a modern remote lab tool as an open educational resource for training graduate students in renewable energy. The remote operated laboratory allows the establishment of working conditions and the download of data recorded following measurements made by users, through the website. The configuration of the laboratory transforms the water electrolysis experiment into a tool for further exploration of physical principles and the laws that govern them. Using remote connectivity, this experiment can be integrated in common study platforms for renewables.
Article no. 904: PDF 
Study of electrocardiogram and peripheral oxygen saturation values - An interdisciplinary approach at high school level
M. COLŢ, F. DRAGOMIR, V. BARNA
Rom. Rep. Phys. 74, 905 (2022)
Abstract. The paper refers to an interdisciplinary study of the electrical activity of the heart, realized at the high school level. The experiment aims to familiarize high school students with the basics about collecting cardiac electrical potentials and presents two alternative methods of obtaining an electrocardiogram, along with its interpretation using the notions learned by high school students in physics and biology. The graphical recording of the global electrical activity of the heart muscle was made with a portable device called ECG monitor PM10 and the oxygen saturation of the hemoglobin in the blood was obtained with the CMS50D + Pulse Oximeter. These portable devices are interfaced with the computer, requiring PM 10 software and SpO2 Assistant applications, respectively. The electrocardiogram was recorded through the Einstein tablet, via an attached ECG sensor and the pulse value was obtained with a smartphone equipped with the Samsung Health application. The study conducted to an understanding of the interactions that steer to heart rate variability and could definitely help prevent, diagnose, predict and treat diseases involving the cardiovascular system.
Article no. 905: PDF 
Modelling the oscillatory motion with GeoGebra software
ANDA CIOBANU, CRISTINA MIRON, C. BERLIC, V. BARNA
Rom. Rep. Phys. 74, 906 (2022)
Abstract. This paper presents the use of GeoGebra software in learning oscillatory motion. We created interactive models for the undamped oscillatory motion, composition of parallel oscillations, damped oscillatory motion subjected to resistive and constant friction force. Each model is briefly discussed theoretically and followed by explanations about the employed GeoGebra applets. The parameters of the simulations can be adjusted by means of visual controls, allowing users to have a broad degree of interaction with the application.
Article no. 906: PDF 

This is an electronic version of Volume 74 Number 3 2022
 
   
 
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