ANTOANETA ENE, ANA PANTELICĂ, FLORIN SLOATĂ, HESHAM M.H. ZAKALY, HUSEYIN OZAN TEKIN
{"title":"Gamma Spectrometry Analysis of Natural and Man-Made Radioactivity and Assessment of Radiological Risk in Soils Around Steel Industry","authors":"ANTOANETA ENE, ANA PANTELICĂ, FLORIN SLOATĂ, HESHAM M.H. ZAKALY, HUSEYIN OZAN TEKIN","doi":"10.59277/romjphys.2023.68.803","DOIUrl":"https://doi.org/10.59277/romjphys.2023.68.803","url":null,"abstract":"\"In this paper low background high-resolution gamma spectrometry was used for the determination of the activity concentrations of the natural and man-made radionuclides in topsoil samples collected in the vicinity of a large steel plant in Galati, Romania. Their values (mean ± standard deviation) for 238U, 226Ra, 232Th, 235U, 210Pb, 40K and 137Cs were: 38.1 ± 6.2; 35.9 ± 5.4; 35.5 ± 3.0; 1.8 ± 0.4; 47.3 ± 8.6; 504.5 ± 38.9 and 7.2 ± 4.7 Bq·kg–1, respectively. 60Co and 241Am had activities below the detection limit: 0.6–1.3 and 2.2–4.7 Bq·kg–1, respectively. The results indicate inputs of natural radionuclides in the sites close to the slag dump, raw materials transportation facility, ore and coal processing factories, blast furnaces, and iron scrap deposit. The evaluation of the associated radiological impact was performed based on selected hazard parameters: absorbed gamma dose rate, total external gamma dose rate, radium equivalent activity index, external hazard index, representative level index, annual effective dose, excess lifetime cancer risk, and annual gonadal dose.\"","PeriodicalId":54449,"journal":{"name":"Romanian Journal of Physics","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135487947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Constructing Families of Solutions to an Integrable Time-Dependent Shallow Water Wave Equation in (1+1)-Dimensions","authors":"ZHOU-ZHENG KANG, RONG-CAO YANG","doi":"10.59277/romjphys.2023.68.112","DOIUrl":"https://doi.org/10.59277/romjphys.2023.68.112","url":null,"abstract":"In this paper, an integrable shallow water wave equation with timedependent coefficients in (1+1)-dimensions is taken into account. Through employing the generalized three-wave methods, a series of (double) solitary wave solutions and periodic (solitary) wave solutions to the considered equation are presented with the aid of symbolic calculation. Furthermore, by specifying relevant functions and parameters, the localized structures of some resulting solutions are displayed via some figures. These results enrich the diversity of nonlinear waves in physics.","PeriodicalId":54449,"journal":{"name":"Romanian Journal of Physics","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135487591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. N. STAICU, O. A. DIACONU, C. PETCU, C. NICOLICESCU, C.N. CUMPĂTĂ, I. SUCIU, A.D. POPESCU, A. Ş. PETRACHE, M. J. ŢUCULINĂ, L. P. DRAGOMIR, P. PERLEA
{"title":"Roughness and Wear Resistance in the Process of Selecting Composite Resins","authors":"A. N. STAICU, O. A. DIACONU, C. PETCU, C. NICOLICESCU, C.N. CUMPĂTĂ, I. SUCIU, A.D. POPESCU, A. Ş. PETRACHE, M. J. ŢUCULINĂ, L. P. DRAGOMIR, P. PERLEA","doi":"10.59277/romjphys.2023.68.703","DOIUrl":"https://doi.org/10.59277/romjphys.2023.68.703","url":null,"abstract":"\"Due to the the multitude of composite materials available, choosing the most adequate ones is a difficult task. Apart from most relevant characteristics such as aesthetics and mechanical strength, it is just as important to obtain smooth restorations, given the negative effects of bacterial plaque retention on the stomatognathic system. We have considered four of the composite resins most frequently used by dentists in Romania and we used laboratory tests to analyse the wear resistance and surface roughness after applying 3 finishing systems. We show that finishing systems have a powerful impact on composite materials roughness, and the best results are obtained with a microhybrid composite. As for wear resistance, nanohybrid composites proved to be superior to microhybrid ones. The results of the study suggest that the structure of the composite material counter-balances its roughness. From a clinical perspective, the quality of the surface of dental restorations is important not only functionally, preventing their wear and bacterial plaque retention, but also from an aesthetical point of view. \"","PeriodicalId":54449,"journal":{"name":"Romanian Journal of Physics","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135487833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Dehydrogenation in Electron-Induced Dissociative Ionization of Pyridine Molecule","authors":"MICHAL K. JURKOWSKI, TOMASZ J. WASOWICZ","doi":"10.59277/romjphys.2023.68.205","DOIUrl":"https://doi.org/10.59277/romjphys.2023.68.205","url":null,"abstract":"\"The electron-impact dissociative ionization of pyridine has been investigated using mass spectrometry. Thirty-two well-resolved mass peaks have been identified in the cation mass spectra and assigned to the most likely ionic molecular fragments. The new sixteen ionic fragments' appearance energies have been determined, and sixteen others remeasured. The total cross-section for electron-impact ionization of pyridine has been measured at 100 eV. Thorough analysis indicates that at least three peaks' groups in the mass spectra occur via the shake-off dehydrogenation mechanism, i.e., by sequential hydrogen atoms elimination from the pyridine parent cation or its fragmentation products. The nature of this process is deciphered. \"","PeriodicalId":54449,"journal":{"name":"Romanian Journal of Physics","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135487590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Exact Solution of the Position-Dependent Mass Schrödinger Equation with the Completely Positive Oscillator-Shaped Quantum Well Potential","authors":"E.I. JAFAROV, S.M. NAGIYEV","doi":"10.59277/romjphys.2023.68.111","DOIUrl":"https://doi.org/10.59277/romjphys.2023.68.111","url":null,"abstract":"\"Two exactly-solvable confined models of the completely positive oscillator-shaped quantum well are proposed. Exact solutions of the position-dependent mass Schrodinger equation corresponding to the proposed quantum well potentials are ¨ presented. It is shown that the discrete energy spectrum expressions of both models depend on certain positive confinement parameters. The spectrum exhibits positive equidistant behavior for the model confined only with one infinitely high wall and nonequidistant behavior for the model confined with the infinitely high wall from both sides. Wavefunctions of the stationary states of the models under construction are expressed through the Laguerre and Jacobi polynomials. In general, the Jacobi polynomials appearing in wavefunctions depend on parameters a and b, but the Laguerre polynomials depend only on the parameter a. Some limits and special cases of the constructed models are discussed.\"","PeriodicalId":54449,"journal":{"name":"Romanian Journal of Physics","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135487661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Antiferromagnet on Pyrochlore Lattice in Spherical Approximation","authors":"R. BUNDARU","doi":"10.59277/romjphys.2023.68.617","DOIUrl":"https://doi.org/10.59277/romjphys.2023.68.617","url":null,"abstract":"\"We develop an 1/n expansion method for the systematic approximation of the solutions of classical spin systems (tri-dimensional vectors) which can describe general spin-spin interactions and phases with complex magnetization pattern. This method is applied to study the phase transitions observed in pyrochlore crystals (e.g. Gd2Ti2O7) and the results have qualitative agreement with the experimental ones.\"","PeriodicalId":54449,"journal":{"name":"Romanian Journal of Physics","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135487819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
WEAAM ALHEJAILI, ABDUL-MAJID WAZWAZ, S. A. EL-TANTAWY
{"title":"Derivation of Lump Solutions to Integrable (2+1)- and (3+1)-Dimensional Extended KdV and KP Equations","authors":"WEAAM ALHEJAILI, ABDUL-MAJID WAZWAZ, S. A. EL-TANTAWY","doi":"10.59277/romjphys.2023.68.113","DOIUrl":"https://doi.org/10.59277/romjphys.2023.68.113","url":null,"abstract":"\"In this study, we investigate the lump solutions for both integrable (2+1)- and (3+1)-dimensional extended KdV and KP equations using symbolic computation with Maple and the Hirota bilinear (HB) form. For each integrable model, we create positive quadratic function solutions to the HB equation. Graphs of the derived lump solutions are displayed with the proper parameter values. \"","PeriodicalId":54449,"journal":{"name":"Romanian Journal of Physics","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135488108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Minimizing Radioactive Waste through Chemical Decontamination Techniques","authors":"D. GURAU, I. IORGA, L. ZICMAN, L. DONE, E. NEACSU","doi":"10.59277/romjphys.2023.68.909","DOIUrl":"https://doi.org/10.59277/romjphys.2023.68.909","url":null,"abstract":"\"Effective decontamination is crucial for managing radioactive waste, and it is important to find optimal practices that consider factors such as ease of use, reduction in secondary waste, and hazardous nature of the material. The study evaluates a chemical decontamination gel effectiveness in removing radioactive materials from commonly used materials at IFIN-HH. Artificially contaminated materials were tested, and the gel decontamination factor was evaluated. The gel has advantages such as easy application, high decontamination factor, and minimal contamination of radioactive materials, making it a promising method for efficient and safe management of radioactive waste. \"","PeriodicalId":54449,"journal":{"name":"Romanian Journal of Physics","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135488286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Dispersion Equations of Transverse Electromagnetic Waves Narrowly Localized Near the Interface between the Media with Different Graded-Index Profiles","authors":"S.E. SAVOTCHENKO","doi":"10.59277/romjphys.2023.68.206","DOIUrl":"https://doi.org/10.59277/romjphys.2023.68.206","url":null,"abstract":"\"Combinations of three pairs of contacting media with linear, exponential, and parabolic profiles of dielectric permittivity are described theoretically. Three new types of narrowly localized transverse electric waves propagating along the interfaces between the considered graded-index media are found. The exact dispersion equations for each type of the waves determining the effective refractive index in dependence on optical and geometric characteristics are obtained. The influence of the thicknesses of the graded-index layers on dispersion equation solutions is analyzed. It is found that the effective refractive index increases with an increase in the thickness of the gradedindex layers in all considered combinations of the contacting media. The thickness of the parabolic graded-index profile has the least significant effect on the effective refractive index, compared to the linear and exponential ones. \"","PeriodicalId":54449,"journal":{"name":"Romanian Journal of Physics","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135488118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Dosimetric Evaluation of the Benefits of Intensity Modulated Techniques in Cervical Cancer Radiotherapy","authors":"IOZSEF GAZSI, LOREDANA G. MARCU","doi":"10.59277/romjphys.2023.68.702","DOIUrl":"https://doi.org/10.59277/romjphys.2023.68.702","url":null,"abstract":"\"External beam radiotherapy for cervical cancer using 3D conformal radiotherapy (3D-CRT) is a standard procedure in Romania. A dosimetric planning comparison between 3D-CRT and intensity modulated techniques evaluating both target parameters and organs at risk could justify the implementation of the latter techniques in clinical settings. 50 cervical cancer patients were treated with 3D-CRT, and equivalent plans simulated with IMRT and VMAT for a comparative dosimetric assessment. In addition to providing better compliance and homogeneity, intensity modulated techniques provide superior protection for organs at risk, especially for bowel bag, influencing patients’ quality of life. \"","PeriodicalId":54449,"journal":{"name":"Romanian Journal of Physics","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135488288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}