Volume 57, Number 9-10, 2012
History of Physics
Disquisitiones Matematicae et Physicae, a Precursory of Romanian Reports in Physics Gheorghe Stratan, Liviu Mircea Romanian Journal of Physics 57,
1255-1260 (2012)
Appeared as a publication of King Charles II Institute of Scientific Research, Disquisitiones grouped the most important mathematicians and physicists from Bucharest. The new publication features and its connections with the scientific, social and historical events in Romania and abroad during its short and tense lifespan (1940–1948) are described.
Theoretical Physics
Variational Calculus with Fractional and Classical Derivatives Mohamed A. E. Herzallah Romanian Journal of Physics 57,
1261-1269 (2012)
This paper presents necessary and sufficient optimality conditions of EulerLagrange type for fractional variational problems with functionals containing classical derivatives and right or left fractional derivatives in both Riemann-Liouville and Caputo senses. We use, as variational functionals, right and left fractional integrals instead of the classical integral.
Integrals for Time-Dependent Complex Dynamical System in One Dimension Jasvinder Singh Virdi Romanian Journal of Physics 57,
1270-1277 (2012)
Construction of exact integrals for dynamical system on an Extended Complex Phase Space (ECPS) of second order in one-dimension has carried out. To achieve this we use Lie algebraic method to study complex systems on the extended complex phase plane characterized by $x = x_1 + ip_2$ , and $p = p_1 + ix_2$. Such integrals play an important role in the analysis of complex trajectories of quantum systems.
Fractional Perturbation Technique of Fractional Differentiable Functions Ming-Bo Wei, De-Qiang Zeng Romanian Journal of Physics 57,
1278-1284 (2012)
In this paper, a fractional perturbation approach is proposed to approximately solve local fractional differential equations. Two examples are used to illustrate the method’s efficiency and convenience.
Atomic Physics
Quasi-Stationary Electron States in Spherical Anti-Dot with Donor Impurity V. Holovatsky, O. Makhanets, I. Frankiv Romanian Journal of Physics 57,
1285-1292 (2012)
The electron energy spectrum in AlxGa1-xAs/GaAs semiconductor quantum anti-dot with donor impurity, placed into the center of a nanostructure is studied. The energies and semi-widths of the quasi-stationary states are defined within the distribution of the probability density of electron residence in quantum anti-dot.
Testing a Low Cost Digital Fluoroscopic System Simona Babeţi (Pretorian), V. Chiriţoiu, R. Maria, R. Popescu, V. Dorobanţu Romanian Journal of Physics 57,
1293-1307 (2012)
In order to develop a Digital Fluoroscopic System (DFS) we built-up, and tested, using a 900 W power X ray source, a filmless device to be used for usual X ray and 192Ir gamma rays nondestructive material testing. The DFS improves the image quality, reduces the inspection time, storage costs and the impact on environment. Manufacturing the DFS, some procedure must be followed according to the standard E2597. We have tested the Basic Spatial Resolution (SRb), the detector Signal-to-Noise Ratio-normalized (dSNRn), the Contrast-to-Noise Ratio (CNR), (the CSa-Contrast Sensitivity was calculated) and the specific material thickness range (SMTR).
Nuclear Physics
The Characterization of Alpha Particles Micro Beams Obtained with Tapered Glass Capillaries D. Dudu, O. Muresan, S. Nitisor, I. Rusen, H. Schubert, I. Vata Romanian Journal of Physics 57,
1308-1316 (2012)
The alpha particles beams of 3.0 MeV energy, obtained by a particle accelerator of Cyclotron type, U-120, are collimated by tapered glass capillaries (collimated beams). The experiments were performed on capillaries with an outlet diameter of different dimensions in the micrometers range (1 µm up to 200 µm). The beams characteristic parameters (angular divergence, intensities and energetic spectra) were measured using different set-up based on Rutherford Back Scattering (RBS) method. Experimental data have shown that the density of the beam strongly depends on the outlet diameter and the tendency is that the density increases versus diameter.
Nuclear Reaction Rates and the Primordial Nucleosynthesis Abhishek Mishra, D. N. Basu Romanian Journal of Physics 57,
1317-1327 (2012)
The theoretical predictions of the primordial abundances of elements in the BigBang Nucleosynthesis (BBN) are dominated by uncertainties in the input nuclear reaction rates. We investigate the effect of modifying these reaction rates on light element abundance yields in BBN by replacing the thirty-five reaction rates out of the existing eighty-eight. We have studied these yields as functions of evolution time or temperature. We find that using these new reaction rates results in only a little increase in helium mass fraction over that obtained previously in BBN calculations. This allows insights into the role of the nuclear reaction rates in the setting of the neutron-to-proton ratio during the BBN epoch. We observe that even with considerable nuclear physics uncertainties, most of these nuclear reactions have minimal effect on the standard BBN abundance yields of 6Li and 7Li.
Simulation Response of Resistive Plate Chamber for Fast Neutrons Using GEANT4 MC Code M. Jamil, J. T. Rhee, H. Y. Jo, Farzana Ahmad, Y. J. Jeon Romanian Journal of Physics 57,
1329-1334 (2012)
This paper describes a possibility of using the resistive plate chamber for the detection of fast neutrons. In this technique, a thin polyethylene layer has been coated on the resistive electrode as a fast neutron converter. The converter layer makes RPC sensitive to fast neutrons. Two types of RPC configurations with polyethylene as converter material were simulated by GEANT4 MC Code using the QGSP_BERT_HP and QGSP_BIC_HP physics lists. For the purpose, fast neutrons in the energy range of 1.0–20.0 MeV, and upto higher energies 100.0 MeV were inserted on the chamber surface. With 0.5 mm thick converter, using the fast neutrons the detection efficiencies for the forward and backward converter-coated RPC configurations were 1.58×10-2 and 2.38×10-2 using QGSP_BERT_HP respectively. With the same detector’s configuration and source the efficiencies were 1.55×10-2 and 2.04×10-2 with QGSP_BIC_HP. The results predict that the response of fast neutrons could be computed successfully with RPC-detector equipped with polyethylene converter.
Alpha Decay Favoured Isotopes of Some Superheavy Nuclei: Spontaneous Fission versus Alpha Decay O. V. Kiren, S. B. Gudennavar, S. G. Bubbly Romanian Journal of Physics 57,
1335-1345 (2012)
Spontaneous fission and alpha decay are the main decay modes for superheavy nuclei. The superheavy nuclei which have small alpha decay half-life compared to spontaneous fission half-life will survive fission and can be detected in the laboratory through alpha decay. We have studied the alpha decay half-life and spontaneous half-life of some superheavy elements in the atomic range Z = 100-130. Spontaneous fission half-lives of superheavy nuclei have been calculated using the phenomenological formula and the alpha decay half-lives using Viola-Seaborg-Sobiczewski formula (Sobiczewski et al. 1989), semi empirical relation of Brown (1992) and formula based on generalized liquid drop model proposed by Dasgupta-Schubert and Reyes (2007). The results are reported here.
A. Sobiczewski, Z. Patyk, S. Ćwiok, Deformed superheavy nuclei, Phys. Lett. B 224, 1 (1989). B. A. Brown, Simple relation for alpha decay half-lives, Phys. Rev. C 46, 811 (1992). N. Dasgupta-Schubert, M. A. Reyes, The generalized liquid drop model alpha-decay formula: predictability analysis and superheavy element alpha half-lives, Atomic Data and Nuclear Data Tables 93, 90 (2007).
SHAPE Transition and Collective Excitations in Neutron–Rich 170-178Yb Nuclei F. I. Sharrad, H. Y. Abdullah, N. Al-Dahan, A. A. Mohammed-Ali, A. A. Okhunov, H. Abu Kassim Romanian Journal of Physics 57,
1346-1355 (2012)
Energy levels, B(E2) values and potential energy surface for even-even 170-178Yb isotopes have been calculated using the IBM-1. The predicted energy levels, B(E2) values and intrinsic quadrupole moments Q0 results were reasonably consistent with the experimental data. The contour plot of the potential energy surfaces shows all interest nuclei were deformed and have rotational characters.
Influence of Normal and Anomalous Doppler Effects on Synchrotron-Cherenkov Radiation A.V. Konstantinovich, I. A. Konstantinovich Romanian Journal of Physics 57,
1356-1366 (2012)
The structure of spectral distribution of the radiation power of the synchrotron Cherenkov radiation of one, two, three and four electrons moving in a spiral in a transparent medium with relativistic longitudinal velocity component (the component parallel to the magnetic induction vector) is investigated. The influence of the coherence factor on the spectrum of synchrotron-Cherenkov radiation for two, three and four electrons is analyzed.
Condensed Matter
Ageing Behavior of He DBD Treated Glass Surface A. Simon, O. E. Dinu, M. A. Papiu, C. D. Tudoran, S. D. Anghel Romanian Journal of Physics 57,
1367-1374 (2012)
This paper reports the ageing behavior of a 1.74 MHz cross-field He Dielectric Barrier Discharge (DBD) treated glass surface. The spectroscopic characterization identified the reactive species and confirmed the non-thermal and non-equilibrium character of the discharge. Water contact angle measurements and AFM topography demostrated the enhancement of hydrophilicity and cleaning of the surface.
Solubility Limits of Erbium in Partially Disordered Crystals Langanite and Langatate O. Toma, L. Gheorghe, R. Birjega Romanian Journal of Physics 57,
1375-1381 (2012)
Solubility limits of Er3+ in partially disordered crystalline compounds langanite (La3Ga5.5Nb0.5O14) and langatate (La3Ga5.5Ta0.5O14) are reported. The compounds are synthesized by solid-state reaction. X-ray powder diffraction analysis is used to determine the solubility limit of Er3+ in the two compounds.
Plasma Physics
High Frequency Inverter Based Atmospheric Pressure Plasma Treatment System C. D. Tudoran, V. Surducan, A. Simon, A. M. Papiu, O. E. Dinu, S. D. Anghel Romanian Journal of Physics 57,
1382-1391 (2012)
The work presents a new laboratory-made atmospheric pressure plasma treatment system based on a modern half-bridge type inverter circuit (1.71 MHz, 200 W) combined with a Tesla resonator. The cold non-thermal plasma is generated in flowing helium. It was characterized and was tested for surfaces treatment.
Comparative Studies on the Structural Properties of Plasma Treated Bioglasses and Composites A. Simon, O. Dinu, M. Papiu, V. Simon, H. Mocuta, J. Papp, S. D. Anghel Romanian Journal of Physics 57,
1392-1402 (2012)
This paper reports a comparison of the structural properties of some bioglasses and polyvinyl alcohol-bioglasses composites in order to use them for medical purposes. A cross-field dielectric barrier discharge treatment was applied for surface functionalization. Changes in glass surface were analyzed using several physical-chemical methods.
Spectral Properties in Photodynamic Plasma Therapy Applications P. Chiru, I. Jepu, C. Porosnicu, A. M. Lungu, C. P. Lungu Romanian Journal of Physics 57,
1403-1410 (2012)
Efficient photodynamic therapy application requires a constant improvement in the transmission radiation technology for different types of photosensitizing compounds in order to destroy malignant tumors. A system that allows testing of different spectral tubes filled with Ar or Xe at variable gas pressure and with different electrode configurations was conceived. An AC high voltage signal with peak amplitude of ~ 1 kV and a frequency of 9.7 kHz was used to ignite the discharge. The electron temperature of about 0.5 to 1 eV has been evaluated using a method based on line intensities ratio from the emission spectra. In this work an analysis of the optical emission spectra, of the spatial distribution of the electron temperature and also the discharge gas pressure dependency on the electron temperature is carried out.
Environmental Physics
Heavy Metals in Pollen Samples Collected from the Dambovita County Analysed by EDXRF Method Gabriel Dima, Ion V. Popescu, Sergiu Dinu Romanian Journal of Physics 57,
1411-1416 (2012)
The purpose of the study is to evaluate the use of the pollen as bio-indicator of environmental pollution. The content in Fe, Mn, and Zn from pollen samples uniformly distributed in Dambovita county was determined using the Energy Dispersive X-Ray Fluorescence Spectrometry (EDXRF). We have collected samples during April 2009 from 18 bee houses from private farms, kipped in industrial-urban and non industrialrural areas. The samples were analyzed with an Elvax EDXRF spectrometer having a solid state Si-pin-diode detector with thermo-electrical cooling with 165 eV at 5.9 keV (Fe55 isotope) energy resolution. We found differences between the two kinds of samples and we concluded that the pollen can be used for bio-monitoring of environment for Fe, Mn, and Zn.
Soil to Rice Transfer Factor of the Natural Radionuclides in Malaysia M. A. Saeed, Siti Sarah Yusof, I. Hossain, R. Ahmed, H. Y. Abdullah, M. Shahid, A. T. Ramli Romanian Journal of Physics 57,
1417-1424 (2012)
Study on environmental radiation protection and determination of contamination of natural radionuclides such as Uranium, Thorium and Potassium in soil and crops samples are very important as part of environmental health surveillance programs projects to develop a subject of interest in the environmental sciences. In the present study, we have detected natural radioactivity elements U, Th and K in soil and paddy crops. The samples were collected from two places at Kedah in Malaysia. The transfer factor (TF) of uranium for five rural areas was measured by the Gamma ray spectroscopy and high-purity Ge (HPGe) detector as 0.20, 0.16, 0.17, 0.14 and 0.11 respectively. Whereas the TF values of thorium were found to be 0.15, 0.05, 0.04, 0.02 and 0.05, respectively. On the other hand for potassium the TFs values were 1.43, 1.20, 0.11, 0.52 and 0.53 respectively. Similarly, the transfer factors for five selected urban areas were measured 0.05, 0.06, 0.08, 0.04 and 0.09 for uranium, 0.01, 0.05, 0.11 and 0.03 for thorium and 0.24, 1.05, 0.09, 0.14 and 4.12 for potassium respectively. The outcomes satisfied the standards of IAEA.
Earth Physics
The Focal Mechanism of Low Magnitude Crustal Earthquakes from Vrancea Region and Adjacent Area L. Ardeleanu Romanian Journal of Physics 57,
1425-1437 (2012)
The goal of the study is to retrieve the focal mechanism of low magnitude shallow earthquakes occurred at the bend of Eastern Carpathians, using an inversion method for high frequency local records. A procedure resembling bootstrap approach is applied to evaluate the resolution of the orientation of the double couple component of the seismic moment tensor. The uncertainty estimated allows us correlations of the tension and pressure axes with the stress field in the study area. The results indicate a complex deformation field in the region, consistent with the transition from the compressive regime at intermediate depth to the extensional regime in the crust.
Crustal Models in Romania - II. Moldavian Platform and Adjacent Areas V. Raileanu, D. Tataru, B. Grecu, A. Bala Romanian Journal of Physics 57,
1438-1454 (2012)
A new crustal model for the central and north-eastern part of Romania is relying on the largest database available at this moment. In comparison with previous crustal models the new model takes into account all known data: old and new seismic refraction data, deep seismic reflection data and seismology data recorded by the broadband stations belonging to the Romanian seismic network for monitoring of earthquakes. The new crustal model reveals the topography of the Moho and top of the lower crust discontinuities as well as the areal distribution of the mean P-wave seismic velocities across the Moldavian and Scythians platform and partially for the Eastern Carpathians. The new configuration of the Moho topography map brings some details in the central study area.
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