Volume 69, Number 1, 2017
Editorial on the introduction of Article Number for Romanian Reports in Physics
VALENTIN-IONEL VLAD
Rom. Rep. Phys. 69, 001 (2017)
Article no. 001: PDF 
 
 
THEORETICAL, MATHEMATICAL, AND COMPUTATIONAL PHYSICS
 
Landau quantization and mass-radius relation of magnetized White Dwarfs in general relativity
SOMNATH MUKHOPADHYAY, DEBASIS ATTA, D.N. BASU
Rom. Rep. Phys. 69, 101 (2017)
Abstract. Recently, several white dwarfs have been proposed with masses significantly above the Chandrasekhar limit, known as Super-Chandrasekhar White Dwarfs, to account for the overluminous Type Ia supernovae. In the present work, Equation of State of a completely degenerate relativistic electron gas in magnetic field based on Landau quantization of charged particles in a magnetic field is developed. The mass-radius relations for magnetized White Dwarfs are obtained by solving the Tolman-Oppenheimer-Volkoff equations. The effects of the magnetic energy density and pressure contributed by a density-dependent magnetic field are treated properly to find the stability configurations of realistic magnetic White Dwarf stars.
Article no. 101: PDF 
 
Reliable treatment for solving boundary value problems of pantograph delay differential equation
ABDUL-MAJID WAZWAZ, MUHAMMAD ASIF ZAHOOR RAJA, MUHAMMAD IBRAHIM SYAM
Rom. Rep. Phys. 69, 102 (2017)
Abstract. This work presents an accurate and reliable treatment of the panto- graph equation, which is a delay differential equation that appears in many scientific applications. The Adomian decomposition method and the variational iteration method will be used to carry out this work. Both the Adomian decomposition method and the variational iteration method provide convergent series solutions for linear and nonlinear differential equations. We conduct a comparative study between the two methods by highlighting the specific features of each method. Four linear and nonlinear pantograph equations will be investigated to support this work. The power of the two methods is confirmed.
Article no. 102: PDF 
 
A fractional model of convective radial fins with temperature-dependent thermal conductivity
D. KUMAR, J. SINGH, D. BALEANU
Rom. Rep. Phys. 69, 103 (2017)
Abstract. The principal purpose of the present article is to examine a fractional model of convective radial fins having constant and temperature-dependent thermal conductivity. In order to solve fractional order energy balance equation, a numerical algorithm namely homotopy analysis transform method is considered. The fin temperature is derived in terms of thermo-geometric fin parameter. Our method is not limited to the use of a small parameter, such as in the standard perturbation technique. The numerical simulation for temperature and fin tip temperature are presented graphically. The results can be used in thermal design to consider radial fins having both constant and temperature-dependent thermal conductivity.
Article no. 103: PDF 
 
Multi-rogue waves and triangular numbers
A. ANKIEWICZ, N. AKHMEDIEV
Rom. Rep. Phys. 69, 104 (2017)
Abstract. Multi-rogue wave solutions of integrable equations have a very specific number of elementary components within their structures. These numbers are given by the "triangular numbers" for the n-th-order solution. This contrasts with the case of multi-soliton solutions, where the number of solitons is n. This fact reveals a significant difference between the higher-order rogue waves and the higher-order solitons. Each n-th step of generation of multi-rogue wave solutions adds n elementary rogue waves to the solution, in contrast to n-soliton solutions, where each step adds only one soliton to the existing n-1 solitons in the composition. We provide the mathematical analysis for the number of 'elementary particles' in the composite rogue wave structures.
Article no. 104: PDF 
 
 
ATOMIC, MOLECULAR, AND NUCLEAR PHYSICS
 
Optical diagnostic techniques for estimating gamma radiation energy using optical densitometry
I. GRUIA, M-R. IOAN, P. IOAN
Rom. Rep. Phys. 69, 201 (2017)
Abstract. The main objective of this work is to investigate the changes in optical glass properties when there are exposed to gamma rays, by using different optical diagnosis techniques. The changes due to the colour centres and other defects induced in borosilicate glass by gamma rays were investigated. Four glass samples have been irradiated to about 5 MeV energy gamma rays, produced indirectly by IFIN-HH particles accelerator. The 12C (p,γ) 12C* resonant nuclear reaction was involved in the experiment. The four samples where shielded by 0.5 mm, 1 mm, 1.5 mm, respectively 2 mm thickness of lead, each one resulting in a different darkening density. By inserting the four experimental values into the light absorption by thickness variation relation, the mass absorption coefficient of the absorbent filter can be obtained. Knowing this value and lead simulated absorption curve equation, the energy of the involved nuclear reaction can be obtained. The same method can be used for determining Compton electrons cross sections in lead.
Article no. 201: PDF 
 
 
OPTICS AND PHOTONICS, PLASMA, LASER AND BEAM PHYSICS
 
Anticipated synchronization of semiconductor lasers with passive dispersive reflectors
N. CIOBANU, S. RUSU, V. TRONCIU
Rom. Rep. Phys. 69, 401 (2017)
Abstract. We explore a new model for anticipated synchronization of distributed feedback lasers with passive dispersive reflectors. The influence of device parameters on the anticipated synchronization is discussed. The conditions for delayed, perfect, and anticipated synchronizations are analyzed.
Article no. 401: PDF 
 
Design of periodic structures in a multiple beam interference scheme
L. IONEL, M. ZAMFIRESCU
Rom. Rep. Phys. 69, 402 (2017)
Abstract. Based on holographic interferometry technique, we develop an alternative method for micrometer-sized periodic structures design. The optical setup with 2D spatial light modulator for periodic structures generation is presented. It is shown that this innovative method made possible the rapid generation of periodic structures employing diffractive masks and phase modulation based on multiple beam interference. The designed interference pattern can be formed by controlling the computed greyscale masks parameters. In this work, basic patterns of interference are investigated in case of three-beam correlation. This technique can be used to control the interference pattern distribution based on multiple beams for ultra-fast micron and sub-micron lithography experiments.
Article no. 402: PDF 
 
Multidimensional localized structures in optical and matter-wave media: a topical survey of recent literature
D. MIHALACHE
Rom. Rep. Phys. 69, 403 (2017)
Abstract. We perform a survey of some recent theoretical and experimental studies on multidimensional (two- and three-dimensional) localized structures in optical and matter-wave media in a broad set of physical settings. This article is structured as a resource letter that briefly outlines a large series of results in the areas of multidimensional solitons in optical media, nonlinear structures in parity-time-symmetric systems, rogue waves in multidimensional physical settings, and matter-wave localized structures.
Article no. 403: PDF 
 
A method of virtual image for determination of negative refraction index of a nanomedium
V. SERGENTU, V. URSAKI
Rom. Rep. Phys. 69, 404 (2017)
Abstract. In this paper we propose a method for measuring the negative refraction index of films of optically transparent materials. The method is based on recording the direction of propagation and the shifting of the ray reflected from the film. It is shown that the method can be applied for both macroscopic and nanometric samples. However, a precise control of parameters of the radiation source is needed for using this method in the case of nanometric samples. The conditions for a composite medium to acquire a negative refractive index are discussed.
Article no. 404: PDF 
 
Image reconstruction with back filtered projection algorithms, used in cultural heritage investigations
C. ARMEANU
Rom. Rep. Phys. 69, 405 (2017)
Abstract. The softwares that are currently used in 3D image reconstruction are usually presented as a so called "black box", which contains usually more algorithms. These algorithms are used in mathematics software like MatLab®, Mathematica®, Maple® and other. MatLab®, among others contain a very advanced module for image analysis and in the present work it will be presented a reconstruction of a test image using a back filtered projection (BFP) method, based on the Radon transform. Also we will analyze the image recomposed with 18, 36 and 90 projections.
Article no. 405: PDF 
 
Analysis of polarization degree of the light emergent from the nanoparticles suspensions
C. UDREA
Rom. Rep. Phys. 69, 406 (2017)
Abstract. In this work I have determined the degree of polarization, with a polarimeter setup, of a laser beam which passes through nanoparticles suspension. The main idea is to see how the degree of polarization of the laser is modified after it passes through different nanoparticle suspension media. With this setup we can find the Stokes parameters (S1, S2 and S3) and determinate the degree of polarization. The Stokes parameters, which characterize the state of polarization, are provided as analog output powers. The samples are different metallic nanoparticles in suspension with different dimensions and concentrations.
Article no. 406: PDF 
 
Atmospheric pressure plasma jets in inert gases: electrical, optical and mass spectrometry diagnosis
A.V. NASTUTA, I. TOPALA, V. POHOATA, I. MIHAILA, C. AGHEORGHIESEI, N. DUMITRASCU
Rom. Rep. Phys. 69, 407 (2017)
Abstract. Atmospheric pressure plasmas are continuously studied nowadays as promising tools for worldwide applications. Plasma jet sources are investigated by means of electrical, optical and mass spectrometry diagnosis. Experimental results revealed a strong influence of the discharge geometry and working gas upon plasma dynamics and active species production.
Article no. 407: PDF 
 
 
CONDENSED AND SOFT MATTER PHYSICS
 
Improving the data storage performances with layered nanowires for synthetic antiferromagnetic racetrack memories
D. IONESCU, M. KOVACI
Rom. Rep. Phys. 69, 501 (2017)
Abstract. Racetrack memories based on synthetic antiferromagnets have been studied, representing structures with high storage performances due to the increased velocity of the domain wall (DW) in the nanowires. The active stack of layers in the nanowire was: magnetic layer (CoFeB, CoFe, Co/Ni/Co, Co/Ni) / heavy metal layer (Ru, Pt, Pd) / magnetic layer. The strong spin-orbit coupling, the interface phenomena and the spin Hall effect are interdependent and generate together a spin current and a torque which move the DW with speed controlled by the thickness of the heavy metal layer and the composition of the ferromagnetic layer. The applied field was of (-2...+2) kOe and the propagation current density of (-0.8·1012 A/m2... +0.8·1012 A/m2). DW velocity obtained by simulation methods was represented versus the domain width delta and the Walker breakdown field HW. Maxima of about 1000-1200 m/s were reached under a specific configuration for different composition of the magnetic layer. Modifications caused by the control parameters were registered and discussed. High values of velocity maxima can be obtained by correlation between the parameters characterizing the phenomena implied in the DW motion process in the nanowire. Values of (0.6-2)·103 A/m for HW, respectively of 3-8 nm for delta it appear to be favorable in order to obtain velocity maxima for the considered materials.
Article no. 501: PDF 
 
Impact of functionalisation on the transport through the Adenine molecule
K. KHALILI, H.M. MOGHADDAM
Rom. Rep. Phys. 69, 502 (2017)
Abstract. The influence of electron donating and accepting functional groups OCH3, CH3/CN and CHO on electron transport properties of a single Adenine-based molecular junction has been numerically studied using the density functional based tight-binding method. It has been found that the above mentioned electron acceptor groups have a strong effect on transmission of the molecular junction resulting in a strong drop of conductance. On the other hand, in both electron donating and accepting categories, the partial density of states indicates that the delocalized nature of the p-orbitals of the adenine is responsible for the impressive effect of the functional group with π-symmetric valence orbitals. Furthermore, the CN functional group has an effect on the current-voltage characteristics of the junction, which is distinct from the effects of all the other functional groups studied here.
Article no. 502: PDF 
 
 
BIOPHYSICS AND MEDICAL PHYSICS
 
Proteomic analysis of plasma molecular markers as predictors of differentiated thyroid cancer
A.E. BACIU, E. UYY, V.I. SUICA, R.M. BOTEANU, A.I. POPESCU, C. GIULEA, D. MANDA, C. BADIU, F. ANTOHE
Rom. Rep. Phys. 69, 601 (2017)
Abstract. The differentiated thyroid cancer is the most frequent endocrine cancer with unpredicted biological evolution. This study aimed to identify potential biomarkers from plasma microvesicles, for early detection, diagnosis and prognosis of cancer versus benign follicular adenoma thyroid lesions. Comparative proteomic analysis between tissue and plasma microvesicles identified eight proteins whose abundances were altered: Filamin-A, Ras-related C3 botulinum toxin substrate 1, integrin beta-1, moesin, CD44 antigen, ezrin, vitronectin, and cell division control protein 42 homolog. These proteins in association with the glycosaminoglycans, hyaluronan and heparan sulfate proteoglycans revealed significant alteration levels that may demonstrate participation in tumourigenesis and metastasis.
Article no. 601: PDF 
 
High resolution mass spectrometry analysis of ribosomal proteins in experimental diabetes
E. UYY, V.I. SUICA, R.M. BOTEANU, L. IVAN, F. SAFCIUC, F. ANTOHE
Rom. Rep. Phys. 69, 602 (2017)
Abstract. The present study aimed to determine whether ribosomal proteins could be involved in the onset of diabetic state in the pulmonary tissue. Biochemical assays, electron microscopy and LC-MS/MS analysis were performed on detergent resistant membrane (DRM) microdomains isolated from the lungs of diabetic and non-diabetic mice models. Electron microscopy results showed a well-developed synthesis apparatus in diabetes, demonstrating a high metabolic activity. LC-MS/MS analysis revealed that hyperglycemia has a modulatory effect on the expression of eight ribosomal proteins that co-fractionated with DRMs, pointing out toward a possible novel regulatory pathway in the mechanism of microangiopathy installation in the diabetic lung.
Article no. 602: PDF 
 
Antimicrobial effect on pet films obtained by plasma and silver nitrate/collagen treatments
M. AFLORI, M. DROBOTA
Rom. Rep. Phys. 69, 603 (2017)
Abstract. The generation of an anti-colonization and biocompatible polyethylene terephthalate (PET) surface, by means of plasma followed by wet chemical modification to incorporate silver ions and collagen molecules is the focus of this publication. In order to have the highest yield of collagen and/or silver possible in a reproducible fashion, the parameters of plasma treatments (time, power) were tailored. Various surface characterization methods revealed the effects of the treatments on the polymer surface. The combined surface modifications inhibited bacterial adhesion on the treated polymer and conclusions concerning the best input parameters of plasma treatments were revealed.
Article no. 603: PDF 
 
Photophysical studies on biocomposites based on carbon nanotubes and chlorophyll-loaded biomimetic membranes
M.E. BARBINTA-PATRASCU, N. BADEA, C. UNGUREANU, C. PIRVU, V. IFTIMIE, S. ANTOHE
Rom. Rep. Phys. 69, 604 (2017)
Abstract. A simple bottom-up strategy was used to achieve biocomposites designed from carbon nanotubes decorated with chlorophyll a-loaded biomimetic membranes. The emission fluorescence of chlorophyll a was exploited for monitoring insertion of quercetin in these biohybrids. Morphological aspects of the samples were revealed by AFM analysis. The bio-based composites obtained from multilamellar lipid vesicles, exhibited enhanced antioxidant activity (85%) and high antimicrobial properties against Staphylococcus aureus bacteria (area of inhibition zone was 143 mm2). These findings open up new perspectives for biomedical applications of these biocomposites, as multifunctional scaffolds to carry therapeutic agents.
Article no. 604: PDF 
 
Absorbed dose to water and air kerma results for measurements carried out in an oncology radiotherapy laboratory
A. SCARISOREANU, F. SCARLAT, E. STANCU, E. BADITA, M. DUMITRASCU, C. VANCEA, R. POPA
Rom. Rep. Phys. 69, 605 (2017)
Abstract. This paper presents the comparison between the values for Dw (absorbed dose to water) and Ka (air kerma) measured with both the equipment of the Secondary Standard Dosimetry Laboratory at High Energy - STARDOOR [1], from The National Institute for Laser, Plasma & Radiation Physics - INFLPR and of the Radiotherapy Laboratory for High Energy of the "Prof. Dr. Al. Trestioreanu" Oncology Institute of Bucharest - IOB, following the TRS-398 [2] methodology. The measurements were performed at the Co-60 radiation source from IOB, in identical irradiation conditions. The results of these comparisons suggest that the real value for all measurements is in line with the accepted uncertainty limits. The En numbers (i.e. statistic performance) are |En| ≤ 1 for each laboratory [3], both for Dw and Ka, assuring that the participant laboratories present a high degree of service quality.
Article no. 605: PDF 
 
Long term stability of the performance of a clinical linear accelerator and Z-score assessment for absorbed dose to water quantity
E. BADITA, C.VANCEA, I. CALINA, D. STROE, M. DUMITRACHE, E. STANCU, F. SCARLAT
Rom. Rep. Phys. 69, 606 (2017)
Abstract. Assessment of the z-score was used to evaluate the long term stability of the performance of a clinical linear accelerator. The absorbed dose to water in high energy photon beam was determined at the linear accelerator owned by the clinical dosimetry laboratory in the radiotherapy department of the "Coltea" Clinical Hospital. The z-score was calculated for the absorbed dose measurements made at reference conditions according to IAEA-398 standard, in 2011 and in 2015 following repairs made to the linear accelerator. The measurements were conducted using water proof ionization chambers in a water equivalent phantom at the reference point for a 10 cm × 10 cm field size and at SSD = 1 m. For each ionization chamber the reference points, were determined according to radiation beam quality. The measurements were performed in a photon beam at reference points of 5 g cm-2 and 10 g cm-2. z-score assessment for absorbed dose to water quantity was evaluated according to ISO 13528:2005. The values obtained were found to be in the limits of statistical performance, z = [-2; 2], concluding that laboratory performance is satisfactory.
Article no. 606: PDF 
 
Objective detection of coxarthrosis by thermal analysis measurement techniques
M. VASILE, F. LAMONACA, D.L. CARNI, A. NASTRO, V.CIUPINA, L.E. MOLDOVEANU
Rom. Rep. Phys. 69, 607 (2017)
Abstract. Diagnosis of primary and secondary coxarthrosis even today remains the privilege of medical experience and is based only on patient symptoms. We propose to use thermal analysis measurements as an objective method of diagnosing bone pathology and the degree of disease severity. Thermal analysis can be performed on few milligrams of bone tissue harvested by outpatient biopsy. For validation of thermal analysis, two more expensive techniques have been used: (i) X-Ray powder diffractometry (XRD) and (ii) scanning electron microscopy (SEM).
Article no. 607: PDF 
 
 
ENVIRONMENTAL AND EARTH PHYSICS
 
Measurements of terrestrial gamma dose rates and radon concentrations from indoor air and water in Transylvania region
M. DOLHA, A. TIMAR-GABOR, T. DICU, C. COSMA
Rom. Rep. Phys. 69, 701 (2017)
Abstract. Terrestrial gamma dose rates have been measured using thermoluminescence method in Alba county. More than 150 dosimeters were placed in 52 locations. The obtained values ranged from 41 ± 2 to 91 ± 4 nGy/h, being in agreement with UNSCEAR Report. Radon concentrations for indoor air were performed in 12 locations from Alba county using CR39 detectors accompanied by radon groundwater measurements, being in accordance with WHO and EURATOM Treaty. Annual effective doses due to radon exposure were also calculated. Alongside with previous results, this work represents an important stage in the development of the high resolution environmental radioactivity map for Transylvania region.
Article no. 701: PDF 
 
International intercomparison exercise of active radon devices and passive detectors at the First East European Radon Symposium (FERAS 2012)
B. PAPP, C. COSMA, A. CUCOS (DINU)
Rom. Rep. Phys. 69, 702 (2017)
Abstract. During the First East European Radon Symposium (2012), an Intercomparison Exercise of active devices and passive detectors was organized, at two exposure levels. Medium Radon Exposure was made in the laboratory room at low to medium level by an average radon concentration of hundreds of Bq·m-3 and involved 12 active devices and 8 groups of passive detectors. High Radon Exposure was performed in a calibration chamber at high level by an average radon concentration of thousands of Bq·m-3 and involved 5 active devices and 7 groups of passive detectors. Results of active devices show that mean concentrations of 11 devices from the Medium Exposure and 1 device from High Exposure were inside ± 95% C.I of the means. Results of passive detectors show that the exposure values of 4 groups from the Medium Exposure and 6 groups from the High Exposure were inside ± 20 % admittance level of the reference exposure.
Article no. 702: PDF 
 
Study of fog events using remote sensing data
F. TOANCA, S. STEFAN, L. LABZOVSKII, L. BELEGANTE, S. ANDREI, D. NICOLAE
Rom. Rep. Phys. 69, 703 (2017)
Abstract. Fog is a phenomenon that causes a reduction in visibility, a real obstacle for land, air and sea traffic and therefore has a high economical impact. The aim of this paper is to study fog generation conditions using ceilometer data and vertical profiles of temperature and humidity from radiosounding and Microwave Radiometer HATPRO. Mean sea level pressure and geopotential patterns were used as additional information. The study focused on 2012-2014 period characterized by several fog events over for Magurele location (44.35 N, 26.03 E). The results of this study showed that the dominant fog type is radiation fog.
Article no. 703: PDF 
 
Assessing of the crustal models and active faults systems in Western part of Romania with applications in seismic hazard
A. BALA, V. RAILEANU
Rom. Rep. Phys. 69, 704 (2017)
Abstract. Seismicity in western part of Romania is the result of tectonic evolution, which created a fragmented structure at the crystalline basement level, with blocks that have suffered differential movements due to general tectonic stress in the area, and due to secondary factors such as erosion or lateral variations in density. Some of the faults formed during development of the units under survey were reactivated later in recent periods of stress and became seismogenic faults. The present paper is an analysis of tectonics and seismicity in western part of Romania (Pannonian depression and Transylvanian Basin, and the Apuseni Mountains Orogen). Several maps interpreted by different Romanian authors on local tectonics are presented and a final map with active faults in the region of study is constructed. The first part is a summary of the stress field in the Earth crust and tectonic evolution of the Carpathian area with particular reference to the units analyzed. Each unit is analyzed based on published sources, finally emphasizing the peculiarities of each area and tectonic fault lines known in particular. In a later chapter is a summary of information on the behavior of the stress field of study areas and seismicity zone, the range of magnitude and hypocenter depths registered with mention of the most significant events occurring over time and relative to areas where they were concentrated. In the last chapter fault systems in the study region are presented, their peculiarities as they appear in the available studies projected on the local tectonic structure for each of the areas under examination. Results are reported using the tectonic map of Romania, on which epicentres of earthquakes in the catalog ROMPLUS (NIEP Catalog) by the end of 2010 are projected.
Article no. 704: PDF 
 
 
PHYSICS EDUCATION
Exploring Excel spreadsheets to simulate the projectile motion in the gravitational field
I. GRIGORE, CRISTINA MIRON, E.S. BARNA
Rom. Rep. Phys. 69, 901 (2017)
Abstract. This paper describes an interactive learning tool created with Excel spreadsheets to simulate the projectile motion in the gravitational field taking into account air resistance. The body thrown is considered as point mass and the drag force linear in the speed. The tool allows the analytical and graphical comparison between motion in vacuum and motion in air, in the gravitational field, with the same input data. The trajectory of the body can be viewed in vacuum and in air, separately, for an easier highlight of certain particular aspects, and also comparatively, on the same graph, for a simultaneous observance of differences. For the motion in vacuum, the safety parabola and the ellipse of the points of maximum height have been graphically rendered. For the motion in air, the vertical asymptote of the trajectory has been graphically rendered. For both the motion in vacuum and in air there have been marked on the graphs the maximum height reached by the body and the horizontal distance corresponding to the maximum height. Using the spreadsheet facilities there is provided an approximate method of determining the flight time and the maximum horizontal range for the motion in air. Furthermore, there are comparative presentations of the graphs of velocities and the horizontal and vertical displacements in relation to time. Given the importance of the addressed topic both for ballistics and for various ball sports, the use of the tool in the classroom with the students can be an attractive and motivating factor for the study of Physics. With the rapid graphical feedback to changes in the input data, students can better understand the influence of various parameters on the trajectory and clarify significant concepts such as terminal velocity or the asymptote of a trajectory.
Article no. 901: PDF 
 

This is an electronic version of Volume 69 Number 1 2017
 
   
 
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