Table of contents

Preface:

The International Conference Frontiers in Theoretical and Applied Physics |UAE 2017 was organized by the Department of Physics at the American University of Sharjah (AUS) in partnership with the Emirates Mars Mission and Mohammed Bin Rashid Space Center (MBRSC) in Dubai-United Arab Emirates. The conference was endorsed by the American Physical Society (APS), Materials Research Society (MRS), the Institute of Physics (IOP) in the UK, and the International Astronomical Union (IAU)-Office of Astronomy for Development. It was held on the beautiful campus of the American University of Sharjah (AUS) in the United Arab Emirates between 22-25February,2017. The conference was the first international and interdisciplinary physics conference in the region that attracted such large number of world-leading scientists and experts in the fields of atomic, molecular and optical physics, condensed matter and materials science, astrophysics and space science, nuclear and high energy physics, and mathematical physics. It had a broad international participation from more than 45 countries, with registered delegates numbering over 330. The scientific program included the presentation and discussion of 300 papers, classified as 5 keynote lectures (each lasted 1 hour), 60 invited talks (each lasted thirty minutes), 145 contributed talks (12 minutes each), and 90 posters. The keynote lectures were attended by all conference attendees in addition to undergraduate and graduate students from AUS, and other guests from neighboring institutions. The invited talks were scheduled into parallel sessions, followed by contributed talks, corresponding to the different research areas that constitute the themes of the conference. Those themes included: Atomic, Molecular, and Laser Physics; Materials Science; Astrophysics and Planetary Science; Mathematical Physics; the Solar System and Mars; and High Energy and Particle Physics.

Submission of papers for the conference proceedings was voluntary. 125 manuscripts were received for consideration in the proceedings and 96 were accepted for publication after a peer-review conducted by the conference's scientific committee in consultation with experts in the corresponding fields. The keynote and invited speakers, in addition to some of the international advisory board members, were invited to submit their papers for publication in a dedicated special issue: Focus issue on Theoretical and Applied Physics in Physica Scripta, the broad scope journal of the Royal Swedish Academy of Sciences. Those invited papers are to be reviewed and handled by Physica Scripta itself. The editors of this focus issue are Ali S. Alnaser, Roland Allen, and Suzy Lidström, Editor-in-chief of Physica Scripta.

Details of Conference Chair, lists of Keynote Speakers, Invited Speakers, Editors of the Proceedings, Scientific Committee, International Advisory Board, Local Organizing Committee, Local Logistics, IT-Support and some photos from the conference are available in the PDF.

All papers published in this volume of Journal of Physics: Conference Series have been peer reviewed through processes administered by the proceedings Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

Electronic structure of the molecule SrCl has been investigated by employing the ab initio methods CASSCF/MRCI+Q with Davidson correction in the representation ^2s+1Λ^±, neglecting spin-orbit effects, and using the computational program Molpro. The potential energy curves of the low-lying doublet and quartet electronic states have been investigated. The harmonic vibrational wave number ω_e, the relative electronic energy T_e, referred to the ground state, the rotational constant B_e and the equilibrium internuclear distance R_e, have been calculated for the investigated electronic states. Moreover, the static dipolar moments have been determined in term of the internuclear distance R_e.

Energy levels, wavelengths, transition probabilities, oscillator strengths, line strengths, and lifetimes have been calculated for transitions among the fine-structure levels belonging to the (1s²2s²2p⁶)3s²3p⁶3d¹⁰, 3s²3p⁶3d⁹4l, 3s²3p⁵3d¹⁰4l, and 3s3p⁶3d¹⁰4l (l = s, p, d, f) configurations of the Ni-like Molybdenum, Mo XV. The results for electric dipole (E1), electric quadrupole (E2), magnetic dipole (M1), and magnetic quadrupole (M2) transitions among the lowest levels of Mo XV have been reported and compared with available NIST results.

A profound ringlike pattern coming from the interplay between the intra- and the intercycle interference of electron trajectories can be observed in the deep tunneling ionization regime, and an appropriate experimental condition for the observation of the photoelectron holography was provided.

We numerically solve the fully-dimensional electronic time-dependent Schrödinger equation for an ${{\rm{H}}}_{2}^{+}$ molecular ion. The occurrence of electron localization is investigated to better understand the complex patterns appearing in the high-order harmonic generation (HHG) spectrum. Our studies show that changing trends of electronic acceleration are affected by electron localization at large enough internuclear distances. This effect leads to the complex patterns in the HHG spectrum.

Intense nanosecond four-colour Fourier-synthesized laser fields induce orientation-selective ionization based on directionally asymmetric molecular tunneling ionization. The interferometer-free laser field generator ensures high stability and high reproducibility. Phase-sensitive, orientation-selective molecular tunneling ionization provides a simple way to estimate the relative phase differences between the fundamental light and each harmonic by data-fitting analysis.

Without applying Born-Oppenheimer approximation, the non-relativistic Hamiltonian can be separated into Hamiltonians for the translation of the center of mass and for the rotational and internal motions of the closed many-body system. This exact rotational and internal Hamiltonian can be expressed in terms of three Euler angles for three independent rotations of the system and the rotated Jacobi coordinates for the internal motions.

Applying the concept of quantum hydrodynamics on a hydrogen atom, one can derive an equation of motion which describes the time derivative of the mass current density for the relative motion of the electron and the proton. Since this derivation can be performed with the Ehrenfest theorem, we call this equation the Ehrenfest equation of motion. As quantum hydrodynamics is consistent with Schrödinger's quantum mechanics, the stationary s-wave functions satisfy both the Schrödinger equation and the Ehrenfest equation of motion. It is the purpose of this paper to prove that the stationary s-wave functions satisfy the Ehrenfest equation of motion. From the quantum hydrodynamical point of view, this result for s-wave functions can be interpreted that the Coulomb force density that attracts the electron to the proton is compensated by a quantum force density that is related to the dispersion of the probability density.

Quantum Dot Lasers (QDLs) are promising sources of light because of their favorable properties compared to other light sources. Emission in QDLs can access transitions in ground state (GS) and excited state (ES). Lasing due to the ES extends the spectral range and enables the laser to generate high output powers. Thus, lasing action due to the ES or to the dual lasing regime (GS and ES simultaneously) is expected to increase the applicability of QDLs in many future applications. We present a partially microscopic rate equation model that takes into account lasing action due to both the GS and the ES and distinguishes between both types of carriers (electrons and holes). Also, we present all possible steady-state solutions and we apply a stability analysis to the solutions to determine all stable lasing regimes (lasing due to the GS, lasing due to the ES and the dual lasing regime) to highlight the role of ES transitions. Specifically, we address the appearance of lasing due to the ES to the larger population of the ES and hence to the larger gain in higher injected current regimes.

We present an ab initio study of strong field ionization of aligned ${{\rm{H}}}_{2}^{+}$ by general elliptically polarized laser pulses containing few optical cycles. In particular, we address the effects of laser pulse parameters (light ellipticity and carrier-envelope phase) and molecular alignment on photoelectron momentum distributions (PMDs) of ${{\rm{H}}}_{2}^{+}$.

We present a new formula for the total statistical weight of all Rydberg levels G^ion(n_l, n_h) for which the principal quantum number n is between higher, n_h, and a lower, n_l, limits. This formula can be used for all atoms in the periodic table and for all corresponding ions.

We solve the Schrödinger equation in the spherical or Hylleraas-coordinate systems, and within the framework of the Ritz's variational principle. The eigenvalues, and the eigenfunctions ψ(r) in r- or Hylleraas-space for the 1s²-state of the He-like atoms as a function of two variational parameters are calculated. Using a simple scaling procedure, we calculate the scaled wavefunction as a function of the nuclear charge Z. Given the density of states, ρ(r), the scaling behavior of the information entropies, e.g., Fisher, Shannon and Rényi's entropies, with their powers and products, as functions of Z are calculated. Scaled wavefunctions for the 1s²-state of the He-like atoms, with exchange, have been used to study the scaling behavior. Our results agree with the published results. Furthermore, we present a simple logarithmic equation that shows the dependence of information entropies on Z for He-like atoms. The formulation enhances the computational efficiency of the entropies and other related quantities.

The lowest potential energy curves, for the electronic states of the molecule ZnO in the representation 2s+1 Λ (+/−) have been performed via Complete Active Space Self Consistent Field (CASSCF) using the Multireference Configuration Interaction (MRCI) method with Davidson correction (+Q). An excitation and de-excitation model has been proposed, in analogy to the emission of ZnO nanoparticles. In addition, the minimum energy level with respect to the ground state, Te, the internuclear distance at equilibrium, R_e, the rotational constant, B_e, the vibrational frequency, ω_e, and the static and transition dipole moment, μ, have been investigated for some electronic states. Thirteen new electronic states have been studied here for the first time.

An exact solution of partial quasipotential equations for spin-0 and spin-½ particles with superposition of Nδ-potentials is obtained. Based on this, a method for an approximate solution using a superposition of δ-potentials instead of an arbitrary smooth potential is presented. A smooth analytic potential allowing existence of resonant states is considered. Scattering cross section dependences on various potential parameters are investigated.

In this paper we develop a collective coordinate approach for the dynamics of two solitons, governed by the nonlocal Gross-Pitaevskii equation (GPE). The model adequately describes both the small amplitude and large amplitude dynamics of soliton bound states (also known as soliton molecules), including the dissociation phenomena. Detailed comparison between theoretical predictions and numerical simulations of the governing GPE is presented.

Due to the bosonic nature of the photon, increasing the peak intensity through a combination of raising the pulse energy and decreasing the pulse duration will pile up more and more photons within the same finite region of space. In the absence of material, this continues until the vacuum is stressed to the point of breakdown and virtual particles become real. The critical intensity where this occurs for electrons and positrons – the so-called Schwinger limit – is predicted to be ∼ 10²⁹ W/cm². At substantially lower intensities, however, nonlinear aspects of the quantum vacuum associated with polarization of the vacuum can be explored. These studies become viable at the petawatt level where 10²³ W/cm² and above can be reached. This is an era into which we are just embarking that will provide critical tests of QED and theories beyond the Standard Model of particle physics.

In the present paper we report the temperature dependence of density, refractive indices and dielectric constant of three samples of crude oils. The API gravity number estimated from the temperature dependent density studies revealed that the three samples fall in the category of light oil. The measured data of refractive index and the density are used to evaluate the polarizability of these fluids. Molar refractive index and the molar volume are evaluated through Lorentz-Lorenz equation. The function of the refractive index, F_RI, divided by the mass density ρ, is a constant approximately equal to one-third and is invariant with temperature for all the samples. The measured values of the dielectric constant decrease linearly with increasing temperature for all the samples. The dielectric constant estimated from the refractive index measurements using Lorentz-Lorentz equation agrees well with the measured values. The results are promising since all the three measured properties complement each other and offer a simple and reliable method for estimating crude oil properties, in the absence of sufficient data.

In this study, we report the thermoelectric power (TEP) measurements of Cu_0.5Tl_0.5Ba₂Ca₂Cu₃O_10-δ added with BaSnO₃ nanoparticles. BaSnO₃ nanoparticles were prepared by chemical co-precipitation method, while (BaSnO₃)_x/(CuT1)-1223 superconducting samples with 0.00 ≤ x ≤ 1.50 wt% were prepared using the solid-state reaction method. The standard four-probe technique was applied to measure DC electrical resistivity in the temperature range from 300 to 77 K. Superconducting transition temperature (T_c) increases up to 117.5 for x = 0.25 wt.% and then it decreases with further x addition. The TEP coefficient was measured as a function of temperature in a wide temperature range from ∼77 K (liquid nitrogen temperature) up to 280 K using a standard differential technique. The behavior of the obtained TEP coefficient is suit with high-T_c copper-oxide superconductors. The results were investigated according to two-band model with an extra linear term. Several parameters such as the pseudo-gap temperature (T*), Fermi energy (E_F) and Fermi temperature (T_F) values were calculated and discussed in terms of nanoparticles BaSnO₃ addition.

The optimization of post deposition annealing in GeTe₂ thin films towards structural rearrangements is reported. From X-ray diffraction, the prominent Bragg's peak is identified, and the full width at half maximum (FWHM), grain size, crystal structure, and microstrain are correlated with the annealing temperature. The process of chemical bonding energy from the Raman spectra confers the homopopolar and heteropolar bond formation. However, the assessed structural disorders are discussed in terms of the Tauc parameter.

Charge effect on I-V characteristics of single layer zigzag nanoribbon MoS₂ (Z-NR-MoS2) have been studied using first-principles quantum transport calculations. We show that the internal electric polarization is strongly dependent on dominating edge atoms; hence, two structures with different edge atoms are investigated. Our calculations show that due to this internal polarization a large negative differential resistance (NDR) has been observed.

Magnetostatic spin waves (MSWs) in magnetic dielectrics are perspective candidates for various applications including data processing, spin wave logic and quantum information. They can propagate hundreds of microns, some have nonreciprocal character and can be localized near the film interfaces. Excitation of MSWs by fs-laser pulses is beneficial since it provides local excitation and tunability. We demonstrate a method for the optical pumping of MSWs due to the inverse Faraday effect in magnetic dielectrics. Its essence is in the excitation with a nonuniform distribution of the optical power through the film depth and in optimization of the pump beam size. Propagation of the spin waves is demonstrated by detecting the magnetization dynamics tens microns away from the excitation spot. Variation of the pump beam diameter allows tuning between different types of the excited spin waves.

This study reports the effect of magnetic ions doping on the structural, optical and magnetic properties of ZnO nanoparticles. Samples of Zn_0.97-xMn_0.03Fe_xO, 0.0 ≤ x ≤ 0.1 wt. %, nanoparticles are synthesized by Co-Precipitation route. The synthesized samples are characterized by X-ray diffraction analysis (XRD), Transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectrometer and UV spectroscopy. XRD results reveal the hexagonal wurtzite structure of ZnO with the formation of secondary phase in the Fe-doped samples corresponding to Zinc Iron Oxide. The crystallite size is calculated by X-ray peak broadening using Debye-Scherer's formula, and the results are in good agreement with TEM. The FTIR reveals two major peaks that are shifted toward a lower value when the concentration of Fe ions becomes higher than that of Mn ions. The UV results indicate a shift in the band-gap energy toward lower value upon increasing Fe-content. The study of magnetization hysteresis loop measurements infers that the samples of Zn_0.97-xMn_0.03Fe_xO show a well-defined hysteresis loop, reflecting the paramagnetic behavior.

We consider a finite one-dimensional Ising spin chain under the influence of a dissipative Lindblad environment obeying the Born-Markovian constrain in presence of an external magnetic field with open boundary conditions. We study the effect of a single impurity, located at the terminal or center of the chain, on the time evolution and asymptotic steady state of the bipartite entanglement in the chain starting from a maximally entangled initial state. We found that the impurity has a significant effect on the bipartite entanglement of its nearest spins and can be used to tune their steady state value but has almost no noticeable impact on the far ones. At finite temperature, the thermal excitations suppress the dynamics of the system and reduce the value of the steady state and may completely wipe it out as the temperature is increased, which eliminates the effect of the impurity in that case.

Corrosion is one of the principal causes of degradation to failure of marine structures. In practice, localized corrosion is the most dangerous mode of attack and can result in serious failures, in particular in marine flowlines and inter-field lines, arousing serious concerns relatively to environmental impact. The progress in time of internal corrosion, the location along the route and across the pipe section, the development pattern and the depth of the loss of metal are a very complex issue: the most important factors are products characteristics, transport conditions over the operating lifespan, process fluid-dynamics, and pipeline geometrical configuration. Understanding which factors among them play the most important role is a key step to develop a model able to predict with enough accuracy the sections more exposed to risk of failure. Some factors play a crucial role at certain spatial scales while other factors at other scales. The Mutual Information Theory, intimately related to the concept of Shannon Entropy in Information theory, has been applied to detect the most important variables at each scale. Finally, the variables emerged from this analysis at each scale have been integrated in a predicting data driven model sensibly improving its performance.

EPR measurements were conducted at different temperatures 100K ≤ T ≤ 295K for GdBa₂Cu₃O_7-δ superconducting samples prepared by the conventional solid state reaction technique, added with x wt.% nanosized ferrite of CoFe₂O₄, prepared by chemical co precipitation method, with 0 ≤ x ≤ 0.40 wt.%. A broad isotropic symmetric EPR line with g factor g ≈ 2 is detected for the (CoFe₂O₄)_xGdBa₂Cu₃O_7-δ samples, corresponding to Gd³⁺ ions. The broadness is attributed to the superposition of signals resulting from the clustering of Gd³⁺ ions and the dipole interaction between these ions. The analysis of the absorption curve and its first derivative allowed to obtain several magnetic parameters including the number of spins N participating in EPR resonance which showed a decrease with increasing temperature and the activation energy E_a, which experienced a decrease with x.

Using nonequilibrium Green's functions in combination with density functional theory, we investigated the electronic transport behaviors of single layer zigzag graphene Nano-ribbon (ZGNR) with a Carbon vacancy in edge. The results show that electronic transport properties of the asymmetry ZGNR can be modulated by vacancy in edges, and prominent negative differential resistance (NDR) can be observed. These results may be useful for designing practical devices based on graphene Nano-ribbons.

Solid-state reaction method was used to prepare superconductor samples with nominal composition of (NiO)_x(Bi_1.6Pb_0.4)Sr₂Ca₂Cu₃O_10−δ,where 0.0 ≤ x ≤ 0.2 wt%. The prepared samples were characterized by X-ray diffraction (XRD) as well as scanning electron microscopy (SEM). XRD patterns indicated that the addition of nano-NiO particles to (Bi, Pb)-2223 did not affect the tetragonal structure and their lattice parameters. The thermopower coefficient was measured as a function of temperature from 250 K down to 77 K, using a standard differential technique. The results were analyzed according to the two-band (Fermi-liquid) and the two-band with an extra linear term models. Pseudo gap temperature (T^*), Fermi energy (E_F) and Fermi temperature (T_F) values were calculated and discussed in terms of nano-NiO additions.

The bandgap of thin films Cu-doped TiO₂ nanoclusters prepared using the inert gas condensation (IGC) technique have been investigated at various Cu contents. The samples were characterized using XRD, SEM/EDS and UV-visible spectrophotometer. It was found that doping of TiO₂ thin film nanoclusters with Cu enhance its optical activity and shift it to the visible region; which makes it useful in photocatalytic applications.

Optimizing energy performance of Magnetic Tunnel Junctions (MTJs) is the key for embedding Spin Transfer Torque-Random Access Memory (STT-RAM) in low power circuits. Due to the complex interdependencies of the parameters and variables of the device operating energy, it is important to analyse parameters with most effective control of MTJ power. The impact of threshold current density, J_co, on the energy and the impact of H_K on J_co are studied analytically, following the expressions that stem from Landau-Lifshitz-Gilbert-Slonczewski (LLGS-STT) model. In addition, the impact of other magnetic material parameters, such as M_s, and geometric parameters such as t_free and λ is discussed. Device modelling study was conducted to analyse the impact at the circuit level. Nano-magnetism simulation based on NMAG^TM package was conducted to analyse the impact of controlling H_K on the switching dynamics of the film.

This study investigates the effect of Mn substitution on the structural and mechanical properties of nano BaSnO₃ using X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), Scanning electron microscope (SEM) and Vickers microhardness. For this investigation, samples of type BaSn_1-xMn_xO₃ with 0.04 ≤ x ≤ 0.4 were prepared by co-precipitation method. XRD patterns indicate the formation of single phase cubic structure BaSnO₃ with space group (Pm3m) for 0 ≤ x ≤ 0.1. BaMnO₂ hexagonal phase appears as impurity for x > 0.1. The crystallite size, increases as x increases. Vickers microhardness H_v was carried out at different applied loads varying between 0.98 N and 9.8 N at dwell time 40 seconds. The results show that H_v increases as the Mn-content increases, whereas it decreases as the applied load increase. The H_v results were analysed using Elastic Plastic Deformation and the Modified proportional specimen resistance models. The Vickers microhardness analysis indicates that Modified Proportional Specimen Resistance model is the most suitable one for describing the load independent microhardness region of the investigated samples.

The effect of BaSnO₃ nanoparticles addition on the structural and mechanical properties of (Bi,Pb)-2223 superconducting phase by means of X-rays diffraction analysis (XRD), scanning electron microscope (SEM), electrical resistance and Vickers microhardness measurement was studied. BaSnO₃ nanomaterial and (BaSnO₃)_x(Bi,Pb)-2223 superconducting samples were prepared using co-precipitation method and standard solid-state reaction techniques, respectively. From XRD data, the addition of BaSnO₃ into (Bi,Pb)-2223 phase does not affect the tetragonal structure and the lattice parameters. SEM images indicate that the microstructure of (Bi,Pb)-2223 was enhanced by adding BaSnO₃ nanoparticles by filling its pores and voids. The superconducting transition temperature T_{c as} well as the critical transport current density J_c, estimated from electrical resistivity measurements, are increased up to x = 0.5 wt%, then decreased with further increase in x. Vickers microhardness measurements H_v were carried out at room temperature as a function of applied. The experimental H_v results were analysed in view of Meyer's law, Hays and Kendall (HK) approach, elastic/plastic deformation (EPD) and proportional specimen resistance (PSR). All samples exhibit normal indentation size effect (ISE), in addition to that, the analysis shows that the Hays and Kendall model is the most suitable one to describe the load independent microhardness for (BaSnO₃)_x(Bi,Pb)-2223 superconducting samples.

Tantalum on silver (Ta/Ag) thin films have quickly increased into high research for applied science with the promise of suitable for high temperatures environments and microsystems for electronics applications. Ag and Ta/Ag thin films were deposited on silicon substrates by dc magnetron sputtering method. We choose the dc magnetron sputtering method because it has many advantages, such as high growth rate, the possibility of large area deposition, and low cost. X-ray diffraction (XRD) analysis and four point probe (FPP) were used for determining the prepared samples. For Ag thin film deposited in room temperature, there are no peaks corresponding to Ag in the XRD pattern which demonstrates amorphous structure. Also, the XRD pattern of Ta/Ag thin film illustrates that the peak of Ta has grown to the crystal direction (002), which shows that the structure of deposited Ta layer on Ag thin film becomes a crystalline state from amorphous state. The relationship between thin film resistivity and Ta/Ag film thicknesses are investigated in this paper.

We investigate the effects of Co substitutions the associated magnetic phase changes and the orthorhombic lattice distortions in Nd_0.6Sr_0.4Mn_1-xCo_xO₃. The effect of Co substitutions on the magnetic state and the orthorhombic lattice distortions has been studied. The orthorhombic distortion is found to be maximum (7.377 × 10^-3) for the pure manganite phase and decreases almost linearly with Co doping, reaching its minimum value 1.044 × 10^-3 1.044 × 10^-3 for the pure cobaltites. Similar behavior has been found for unite cell volume. Since Co may have several oxidation states, it may also affect the (Mn⁴⁺/Mn³⁺) ratio, the double magnetic exchange interaction, the magnetic state and metal insulator transition.

Electron paramagnetic resonance (EPR) studies are carried out on composite samples of SmBa₂Cu₃O_7-δ/(MnFe₂O₄)_x superconductors with 0.00 ≤ x ≤ 0.20 wt% at different temperatures 100K ≤ T ≤ 295K. An EPR signal of Cu²⁺ ions in the orthorhombic local symmetry is observed. Moreover, the EPR signal intensity increases as the temperature decreases from room temperature down to 100 K. The temperature dependence of g-factors indicates the pseudogap onset temperature (T*), corresponding to the peak of the observed curves between 127 K and 162 K. The number of spins (N) participating in EPR resonance are calculated as a function of both nanosized MnFe₂O₄ addition and temperature. In particular, it is shown that any EPR signal for SmBa₂Cu₃O_7-δ/(MnFe₂O₄)_x is probably due to small amount of spurious phases typically present in the samples such as BaCuO₂. The presence of BaCuO₂ is confirmed by magnetization-field (M-H) hysteresis measurements

The current–voltage (J-E) isotherms of single crystal FeSe_0.5Te_0.5 sample have been measured at several temperatures near the transition temperature (T_c) and under applied magnetic fields (H). A power law (E ∼ J^β) has been used to fit the data and evaluate the activation energy U_o (T) using β = U_o/k_BT. At low current density (J << J_c), the initial behaviour is associated with thermally activated flux Flow (TAFF) while at J >> J_c vortex flux flow (FF) behavior is expected. The effects of applied magnetic field on FF and TAFF also been investigated. We found that U_o(FF) was reduced with by about an order of magnitude in magnetic fields as low as ∼1.5 Tesla-the reduction in U_o(TAFF) is even faster than in U_o(FF)-hence reflecting the low pinning nature (defects, vacancies etc.) of FeSe_0.5Te_0.5 superconductor.

Pure and composite Resorcinol–Formaldehyde (RF) aerogel samples were prepared by sol-gel process using KOH as a catalyst and doped with silver nanoparticles at different concentrations (1.2×10^-4, 2.4×10^-4, 3.6×10^-4, and 4.8×10^-4 wt.% at catalyst ratio 0.024 wt.%). DC electrical conductivity σ_dc, AC electrical conductivity σ', and the dielectric properties of the prepared samples have been measured at different frequencies and temperatures. The results show that σ' increases with increasing frequency. The values of σ' range from ∼10^-4 Ω^-1m^-1 to around unity at room temperature. The analysis of the results of σ'(ω, T) reveals that the large overlapping polaron (OLP) is the most favorable mechanism to describe the conduction mechanism in these samples. The behavior of the dielectric constant with the frequency of these samples is normal, where it decreases with increasing frequency, while the behavior of dielectric loss tangent tanδ exhibits a peaking behavior at relatively higher temperature.

A series of Resorcinol Formaldehyde (RF) aerogels composites with nanoparticles of sliver were prepared by the sol-gel method at different concentrations doped silver. FTIR spectra of pure and composite RF aerogels show six absorption bands attributed to –OH groups bonded to the benzene ring, stretching of –CH₂– bonds and aromatic ring stretching. FTIR results ensured that sliver particles do not interact with aerogel network. UV-visible spectrum of pure silver show an absorbance peak at 420 nm attributed to the surface plasmon excitation of sliver Nano spheres. UV-visible spectral of pure and composite RF aerogels shows a steep decrease of absorption with wavelength after 500 nm, making sample's color reddish brown. TEM and SEM images of pure and composite RF aerogels revealed that the textural arrangement of RF aerogels can be described as densely packed small nodules.

We study theoretically a cluster of several interacting spins modelling a hypothetical single-molecule magnet. Starting from a spin Hamiltonian, we obtain the individual energy levels and their evolution in an applied magnetic field. By substituting the energy levels into the partition function, we compute macroscopic observables like the magnetisation and the susceptibility of the system.

A structure of gallium antimonide (GaSb) and gallium arsenide (GaAs) wafers is built to modulate light reflectivity at CO₂ laser wavelength. A quantum well composed of GaSb/GaAs heterojunction with highly doped GaAs up to 3×10¹⁸ cm^-3 is inserted inside a layer structure. A grating of periodic structure of GaAs and gold layer is added just below the substrate. Gsolver software is used to determine the reflectivity of incident light with the existence of free carriers. A voltage is applied to the doped layer to deplete the free electrons and the reflectivity is determined again. The significant difference in reflectivity between the two cases can be used to build a light reflectivity modulator device.

In this paper the results of experimental studies of the amplitude-temporal characteristics of a runaway electron beam, as well as breakdown voltage in nitrogen are presented. The voltage pulses with the amplitude in incident wave ≈120 kV and the rise time of ≈0.3 ns was used. The supershort avalanche electron beam (SAEB) was detected by a collector behind the flat anode. The amplitude-time characteristics of the voltage and SAEB current were studied with subnanosecond time resolution. The maximum pressure at which a SAEB is detectable by collector was ∼1 MPa. This pressure increases with decreasing the voltage rise time. The waveforms of the discharge and runaway electron beam currents was synchronized with the voltage pulses. The mechanism of the runaway electron generation in atmospheric-pressure gases is analyzed on the basis of the obtained experimental data.

Elements composition of niobium surface before and after plasma treatment by runaway electron preionized diffuse discharge was investigated in atmospheric pressure nitrogen flow by means of an Auger electron spectroscopy. Surface characterizations obtained from Auger spectra show that plasma treatment by diffuse discharge after exposure of 120000 pulses provides ultrafine surface cleaning from carbon contamination. Moreover, the surface free energy of the treated specimens increased up to 3 times, that improve its adhesion property.

Density functional theory combined with the non-equilibrium Green's function formalism is used to study the conductance response of Fe-doped graphene nano-ribbons (GNRs) to CO₂ gas adsorption. A single Fe atom is either adsorbed on GNR's surface (aFe-graphene) or it substitutes the carbon atom (sFe-graphene). Metal atom doping reduces the electronic transmission of pristine graphene due to the localization of electronic states near the impurity site. Moreover, the aFe-graphene is found to be less sensitive to the CO₂ molecule attachment as compared to the sFe-graphene system. These behaviours are not only consolidated but rather confirmed by calculating the IV characteristics from which both surface resistance and its sensitivity to the gas are estimated. Since the change in the conductivity is one of the main outputs of sensors, our findings will be useful in developing efficient graphene-based solid-state gas sensors.

We have investigated the mechanical properties of the iron-based superconductor (FeSC) SmFeAsO_1−xF_x (Sm1111) with a wide doping range 0.09 ≤ x ≤ 0.3 by performing the Vickers microhardness test. The estimated Vickers microhardness number (H_v) was analysed using Meyer's law, Hays-Kendall approach, elastic/plastic deformation (EPD) model and proportional specimen resistance (PSR) model, where the PSR model showed the best match with our experimental data. H_v values showed an increase as x increases, indicating that fluorine doping results in an improvement in the mechanical properties of the Sm1111 compound and makes it more convenient for applications.

Plasmonic interfaces are integrated to photovoltaic devices to enhance light trapping and improve efficiency. The optimum thickness of the spacer layer used to passivate the absorber layer and adjust its distance from the metal nanoparticles remains unclear. We integrate plasmonic interfaces consisting of Ag nanoparticles and silicon nitride spacers of different thicknesses to the back of a-Si:H absorber to investigate the optimum thickness of the spacer layer and use the photocurrent in a-Si:H to indicate the enhancement in light-trapping. For integration to the back or front of the device, the localized surface plasmon resonance (LSPR) is shifted and broadened into the red with increased spacer layer thickness and the effect is more pronounced for integration to the back. An appreciable enhancement of photocurrent in a-Si:H is consistent with this broadening of LSPR and has a critical dependence on spacer layer thickness.

Transport, magnetic, XRD and XPS studies have been performed on CrAs_1−xSb_x in an effort obtain the phase diagram in the intermediate range (x∼0.5) in the hexagonal phase. We found that CrAs undergoes antiferromagnetic and structure transition at T_N = 240K. Upon Sb substitution (x > 0.3), the Neel temperature is sharply suppressed with slope ($-10.7\frac{K}{x} \%$) in much similar way to the suppression caused by pressure in CrAs single crystal. The chemical compositions obtained using XPS are in good agreement with nominal values. Moreover, XPS reveals no changes in the valance states for the constituent elements of CrAs_1−xSb_x. Unexpectedly, we found that arsenic at the surface has higher atomic ratio than the nominal composition. This may be due to segregation of arsenic to the surface of sample.

Zinc Cobalt nano ferrite doped with Praseodymium, Zn_0.5Co_0.5Fe_2-xPr_xO₄ (0 ≤ x ≤ 0.2), were prepared by co-precipitation method from an aqueous solution containing metal chlorides and two concentrations of poly(vinylpyrrolidone) (PVP) 0 and 30g/L as capping agent. The samples were characterized using X-ray powder diffraction (XRD), Transmission Electron Microscope (TEM), UV-visible optical spectroscopy, Fourier transform infrared (FTIR) and Electron Paramagnetic Resonance (EPR). XRD results display the formation of cubic spinel structure with space group Fd3m and the lattice parameter (a) is slightly decreased for PVP capping samples. The particle size that determined by TEM, decreases for PVP capping samples. The optical band energy E_g increases for PVP capping samples, confirming the variation of energy gap with the particle size. The FTIR results indicate that the metal oxide bands were shifted for the PVP capping samples. EPR data shows that the PVP addition increases the magnetic resonance field and hence decreases the g-factor.

A search for physics beyond the Standard Model (SM) is performed using a final state with multi-muons and collision data collected by the Compact Muon Solenoid (CMS) experiment at the CERN Large Hadron Collider (LHC). The topology under study considers events with pairs of oppositely charged muons (dimuons) with a low invariant mass and a common origin. This selection offers an extremely low contribution from SM processes and fits into several beyond the SM signatures. Results are interpreted in a model-independent fashion and in the context of two scenarios: Supersymmetry including "dark" sectors (dark-SUSY) and Next-to-Minimal Supersymmetric Standard Model (NMSSM). Both scenarios postulate a non-SM decay of the Higgs boson to a pair of new light bosons which subsequently decay to a pair of muons. In the case of the dark-SUSY scenario, the hypothetical production of dark photons could give an insight on the origin of dark matter.

A search for pair production of dark matter candidates and supersymmetry (SUSY) production with two jets in vector-boson fusion (VBF) topology is presented using data collected by the Compact Muon Solenoid (CMS) detector in proton-proton collisions at the Large Hadron Collider (LHC). Final states with no leptons are expected in pair production of dark matter particles or scalar quarks in SUSY compressed mass-spectra scenarios. Final states with low-energy leptons are expected in the production of charginos and neutralinos in SUSY compressed mass-spectra scenarios. Results for both zero and two lepton final states at 8 TeV are presented with brief prospects at 13 TeV.

Direct Dark Matter searches are nowadays one of the most exciting research topics. Several Experimental efforts are concentrated on the development, construction, and operation of detectors looking for the scattering of target nuclei with Weakly Interactive Massive Particles (WIMPs). In this field a new frontier can be opened by directional detectors able to reconstruct the direction of the WIMP-recoiled nucleus thus allowing to extend dark matter searches beyond the neutrino floor. Exploiting directionality would also give a proof of the galactic origin of dark matter making it possible to have a clear and unambiguous signal to background separation. The angular distribution of WIPM-scattered nuclei is indeed expected to be peaked in the direction of the motion of the Solar System in the Galaxy, i.e. toward the Cygnus constellation, while the background distribution is expected to be isotropic. Current directional experiments are based on the use of gas TPC whose sensitivity is limited by the small achievable detector mass. In this paper we show the potentiality in terms of exclusion limit of a directional experiment based on the use of a solid target made by newly developed nuclear emulsions and read-out systems reaching sub-micrometric resolution.

New technique is presented for modeling total cross section of proton-proton (p-p) collision from low to ultra-high energy regions using gene expression programming (GEP). GEP, as a machine learning technique is usually used for modeling physical phenomena by discovering a new function ${{\rm{\sigma }}}_{{\rm{T}}}(\sqrt{s})$. In case of modeling the p-p interactions at the Large Hadron Collider (LHC), GEP is used to simulate and predict the total cross-section which is a function of total center-of-mass from low to high energy √s. The discovered function shows a good match as compared with the other models. The predicted values of total cross section are in good agreement with Particle Data Group (PDG).

To present the main influence of anomalous diffusion on the energetic particle propagation, the fractional derivative model of transport is developed by deriving the fractional modified Telegraph and Rayleigh equations. Analytical solutions of the fractional modified Telegraph and the fractional Rayleigh equations, which are defined in terms of Caputo fractional derivatives, are obtained by using the Laplace transform and the Mittag-Leffler function method. The solutions of these fractional equations are given in terms of special functions like Fox's H, Mittag-Leffler, Hermite and Hyper-geometric functions. The predicted travelling pulse solutions are discussed in each case for different values of fractional order.

Systematic calculations of fission barriers for axial deformation are performed for even-even nuclei in actinides region of the nuclear chart and superheavy nuclei. These calculations were performed using relativistic Hartree-Bogoliubov (RHB) formalism with separable pairing.

The commonly accepted scientific opinions on the inner core as the deformable solid globe are based on the solution of the problem on the distribution of elastic parameters in the inner structures of the Earth. The given solution is obtained within the necessary integral conditions on its self-weight, moment of inertia concerning the axes of rotation and periods of free oscillations of the Earth. It is shown that this solution does not satisfy the mechanics of the deformable solid body with sufficient local conditions following from basic principles concerning the strength, stability and actuality of velocities of propagation of elastic waves. The violation of local conditions shows that the inner core cannot exist in the form of the deformable solid body within the commonly accepted elastic parameters.

The spatial distribution of charge and magnetization within the nucleon (proton and neutron) is encoded in the elastic electromagnetic form factors ${G}_{E}^{(p,n)}$ and ${G}_{M}^{(p,n)}$. These form factors have been precisely measured utilizing elastic electron scattering, and the combination of proton and neutron form factors allows for the separation of the up- and down-quark contributions to the nucleon form factors. We expand on our original analyses and extract the up- and down-quark contributions to the nucleon electromagnetic form factors from worldwide data with an emphasis on precise new data covering the low-momentum region, which is sensitive to the large-scale structure of the nucleon. From these, we construct the flavor-separated Dirac and Pauli form factors and their ratios, and compare the results to recent extractions and theoretical calculations and models.

In this paper, infinite systems of point particles with Yukawa potential and periodic boundary conditions are simulated using Monte Carlo technique in three dimensions. Because of the short range nature of the Yukawa potential, cut-off radius r_cut is considered in calculations (i.e, for each particle i, the effect of the other particles on it inside a sphere of radius r_cut is taken into account). The cut-off radius used in Monte Carlo simulation affects the physical behavior of the system being simulated. A sequence of r_cut values are used. When the change in the total potential energy becomes negligible, the optimum value of the cut-off radius is determined. This value is found to be independent of density and temperature in the NVT-ensemble case.

The complexes build–up of DNA and soft particles poly amidoamine (PAMAM) dendrimers of ammonia cored of generations (G1-G6) and ethylenediamine cored of generations (G1-G10) have been studied, using a new theoretical model developed by Qamhieh and coworkers. The model describes the interaction between linear polyelectrolyte (LPE) chain and ion-penetrable spheres. Many factors affecting LPE/dendrimer complex have been investigated such as dendrimer generation, the Bjerrum length, salt concentration, and rigidity of the LPE chain represented by the persistence length. It is found that the wrapping chain length around dendrimer increases by increasing dendrimer`s generation, Bjerrum length, and salt concentration, while decreases by increasing the persistence length of the LPE chain. Also we can conclude that the wrapping length of LPE chain around ethylenediamine cored dendrimers is larger than its length around ammonia cored dendrimers.

We develop Maggiore and Mancarella non-local model by using new function, ${\rm{f}}({{\rm{m}}}^{2}\frac{{\rm{R}}}{{\square }^{2}})$ and we obtained analytical hyperbolic tangent function. This new model has expansion history exactly as same as ΛCDM (Lambda Cold Dark Matter) with same matter content, but without cosmological constant or dark energy. However, background evolution in our model and ΛCDM are the same, but these models may be distinguishable in structure formation or observation that will contain additional information more than background level.

In this work, we focus on the atom-surface interaction where the geometry of the surface is highly symmetric (i.e. sphere, cylinder and plane) and the atom is in ground state. We first present the main features of our model, based on the susceptibility tensors of the two partners in interaction, to determine a general expression of the dispersive energy of van der Waals interaction. Some results are given as applications of this model which addresses recent nanophysical problems, for example, when atoms are in the vicinity of metallic nanoshells, nanospheres or nanowires.

More than 90 years passed when name plasma was coined and more than 60 years in controlling plasma. It seems to be missing something, may be entropy that depends upon maximum constituents of plasma. Inculcating entropy in theoretical and experimental research may lead to the easy confinement. In this paper, Yaqub's work is extended, transport phenomenon is studied with drift approximation inculcating entropy and η-mode depending upon entropy gradient drift is observed. New dispersion relation is derived by using Branginskii transport equations. Dependence of Anomalous transport on entropy is also observed. This work will be helpful in understanding different phenomena of space plasmas and tokamak specifically the pedestal H-mode.

In order to study the effect of electromagnetic fields (0.3 mT, 50 Hz) on some biomechanical and biochemical properties of rats' blood, healthy thirty male albino rats of 150 ± 10 g were divided into three equal groups namely A, B1, B2. Group A used as a control group, group B1 was continuously exposed to a magnetic field of (0.3 mT, 50 Hz) for a period of 21 days for direct effect studies. Group B2 was continuously exposed to the same magnetic field for the same period of time, then was housed away from the magnetic field for a period of 45 days for delayed effects studies. After examination, the results indicated that the apparent viscosity and the consistency index increased significantly and very high significantly for groub B1 and B2 compared to control at P<0.05. Red blood cell counts (RBCs) membrane elasticity had significantly and very high significantly decreased for groups B1 and B2. Moreover, delayed effects studies indicated that there is deterioration in the bone marrow functions. These results are supported by the blood film image, where irregularities and deformations in the RBCs membranes had been occurred. We conclude that the cell membrane properties are highly affected by the extremely low frequency (ELF) magnetic fields, which proved to be biologically toxic.

After the discovery of the long awaited Higgs boson in 2012, the Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) and its two general purpose experiments (ATLAS and CMS) are preparing to break new grounds in High Energy Physics (HEP). The international HEP collaboration has established a rigorous research program of exploring new physics at the high energy frontiers. The program includes substantial increase in the luminosity of the LHC putting detectors into a completely new and unprecedented harsh environment. In order to maintain their excellent performance, an upgrade of the existing detectors is mandatory. In this work we will describe ongoing efforts for the upgrade of the CMS muon detection system, in particular the addition of detection layers based on the Gas Electron Multiplier (GEM) technology. We will summarize the past 5-year R&D program and the future installation and operation plans.

Constrained mean-field calculations, based on the Gogny-D1M energy density functional, have been carried out to describe fission in Ra, U and Pu nuclei with neutron number 144 ≤ N ≤ 176. Fission paths, collective masses and zero-point quantum vibrational and rotational corrections are used to compute the spontaneous fission half-lives. We also pay attention to isomeric states along the considered fission paths. Alpha decay half-lives have also been computed using a parametrization of the Viola-Seaborg formula. Though there exists a strong variance of the predicted fission rates with respect to the details involved in their computation a robust trend is obtained indicating, that with increasing neutron number fission dominates over α-decay. Our results also suggest that a dynamical treatment of pairing correlations is required within the microscopic studies of the fission process in heavy nuclear systems.

We have conducted a near-infrared monitoring campaign at the UK InfraRed Telescope (UKIRT), of the Local Group spiral galaxy M33 (Triangulum). A new method has been developed by us to use pulsating giant stars to reconstruct the star formation history of galaxies over cosmological time as well as using them to map the dust production across their host galaxies. In first Instance the central square kiloparsec of M33 was monitored and long period variable stars (LPVs) were identified. We give evidence of two epochs of a star formation rate enhanced by a factor of a few. These stars are also important dust factories, we measure their dust production rates from a combination of our data with Spitzer Space Telescope mid-IR photometry. Then the monitoring survey was expanded to cover a much larger part of M33 including spiral arms. Here we present our methodology and describe results for the central square kiloparsec of M33 [1–4] and disc of M33 [5–8].

We study the primordial magnetic field (PMF) generated by the simple inflationary model f²FF in the context of R²-inflationary model, the favourite model of Planck 2015 results. The scale invariant PMF is achieved and the backreaction problem is avoided as long as, the rate of inflationary expansion, H, is less than the upper bound reported by Planck, 2015, in the observable scales of wave numbers, k_η. Based on these results, we find that the upper limit of present magnetic field, B₀ < 8.1 × 10⁻⁹G . It is in the same order of the one reported by Planck, 2015.

The discovery of super-Earths and extra solar giant planets has made high pressure physics relevant for determining the formation and composition of these planets.We have developed a model to determine the pressure dependence of melting temperature, T_m and the Debye temperature, Θ_D of materials utilizing Grüneisen parameter, ξ and the bulk modulus, B as the basic ingredients. The formalism has been applied to estimate the pressure dependence of melting temperature and Debye temperature of one of the candidate minerals such as quartz (stishovite, SiO₂). The pressure range used in the present study is 0-6000GPa commensurate with the interior pressures of giant exoplanets. The results show an excellent agreement with the available experimental and other theoretical results.

Gamma-ray bursts (GRBs) are the most powerful explosions in the universe. They have remained the object of intense research ever since their discovery was declassified in the early 1970s. Several space-borne missions have been dedicated to their study, including the Compton Gamma-Ray Burst Observatory (CGRO) in the 1990s and the current Swift and Fermi satellites. However, despite several decades of focused research, the precise mechanisms behind these enigmatic explosions have not been fully established. In the first part of this paper, we review what is currently known about GRBs. This includes: GRB light-curves and spectra; the different progenitor models, i.e., the "collapsar" and "merger" models; and the afterglow characteristics, including external shocks and the surrounding medium. In the second part of the paper, we present our work, which focuses on utilizing GRBs as cosmological probes. GRBs are ideal cosmological tools, because they have been observed to great distances (redshifts up to z = 9.4) and their radiation is unencumbered by any intervening dust. Although GRBs are not standard candles, the discovery of several energy and luminosity correlations, like the Amati relation which correlates the intrinsic spectral peak energy, E_p,i to the equivalent isotropic energy, E_iso, has ushered in a new era in which GRBs are used to investigate cosmological issues like the star formation rate and the value of the matter-density parameter, Ω_M.

Previous study to investigate the correlation between the transit depth and the stellar metallicity of Kepler's (Q1-Q12) gas giant planets (radii of 5-20R_⊙) has led to a weakly significant negative correlation. We use the cumulative catalog of planets detected by the NASA Kepler mission Q1-Q17 catalog, as of April 2015, to perform a solid statistical analysis of this correlation. In the present work, we revise this correlation, within a Bayesian framework, for two large samples: sample A confirmed planets and sample B (confirmed + candidates). We expand a hierarchical method to account for false positives in the studied samples. Our statistical analysis reveals no correlation between the transit depth and the stellar metallicity. This has implications for planet formation theory and interior structure of giant planets.

We study the influence of quintessential matter on the equations describing the properties of a thin accretion disk around a rotating compact object. From these, we show that quintessence matter may play an important role in the accretion process.

The population of nearby dwarf galaxies in the Local Group constitutes a complete galactic environment, perfect suited for studying the connection between stellar populations and galaxy evolution. In this study, we are conducting an optical monitoring survey of the majority of dwarf galaxies in the Local Group, with the Isaac Newton Telescope (INT), to identify long period variable stars (LPVs). These stars are at the end points of their evolution and therefore their luminosity can be directly translated into their birth masses; this enables us to reconstruct the star formation history. By the end of the monitoring survey, we will have performed observations over ten epochs, spaced approximately three months apart, and identified long-period, dust-producing AGB stars; five epochs of data have been obtained already. LPVs are also the main source of dust; in combination with Spitzer Space Telescope images at mid-IR wavelengths we will quantify the mass loss, and provide a detailed map of the mass feedback into the interstellar medium. We will also use the amplitudes in different optical passbands to determine the radius variations of the stars, and relate this to their mass loss.

Extreme Ultraviolet spectrograph, EXCEED, on-board the HISAKI satellite is designed for observing tenuous gas and plasma around planets in the solar system. It enables us to obtain continuous and long-term data set and find time variability in the planetary magnetosphere and ionosphere with time scales of several hours to months. Here, we introduce new findings of Jupiter's UV aurora and plasma emissions from the Io plasma torus obtained from the HISAKI observation.

We perform a systematic search for astronomical observatory sites in the MENA (Middle-East and North Africa) region using space-based data for all the relevant factors, i.e. altitude (DEM), cloud fraction (CF), light pollution (NTL), precipitable water vapor (PWV), aerosol optical depth (AOD), relative humidity (RH), wind speed (WS), Richardson Number (RN), and diurnal temperature range (DTR). We look for the best locations overall even where altitudes are low (the threshold that we normally consider being 1,500 m) or where the combination of the afore-mentioned determining factors had previously excluded all locations in a given country.

In this aim, we use the rich data that Earth-observing satellites provide, e.g. the Terra and Aqua multi-national NASA research satellites, with their MODIS (Moderate Resolution Imaging Spectroradiometer) and AIRS (Atmospheric Infrared Sounder) instruments, the Defense Meteorological Satellite Program's Operational Linescan System (DMSP-OLS), and other products from climate diagnostics archives (e.g. MERRA).

We present preliminary results on the best locations for the region.

As of today, more than 2500 pulsars have been found, nearly all in the Milky Way, with the exception of ∼28 pulsars in the Small and Large Magellanic Clouds. However, there have been few published attempts to search for pulsars deeper in our Galactic neighborhood. Two of the more promising Local Group galaxies are IC 10 and NGC 6822 (also known as Barnard's Galaxy) due to their relatively high star formation rate and their proximity to our galaxy. IC 10 in particular, holds promise as it is the closest starburst galaxy to us and harbors an unusually high number of Wolf-Rayet stars, implying the presence of many neutron stars. We observed IC 10 and NGC 6822 at 820 MHz with the Green Bank Telescope for ∼15 and 5 hours respectively, and put a strong upper limit of 0.1 mJy on pulsars in either of the two galaxies. We also performed single pulse searches of both galaxies with no firm detections.

In this paper, the emission spectra from plasma jet-water interaction is investigated. The plasma system consists of a quartz tube which is surrounded by two copper strips separated by 14 mm, the upper stripe is connected to AC high voltage power supply and the lower is grounded. A quartz-cuvette containing the water sample is placed at 13 mm down to the tube nozzle. Emission spectra from three regions; the distance between the two electrodes (A), the distance between the grounded electrode and the sample surface (B), and through the sample (C), are investigated. The results show clear differences between the spectra emitted from the three regions. Region A emits the highest intensities for the line spectra and argon 763 nm was the maximum. As well as, O radical emission spectra were detected with the highest intensities in region B. However, new bands and lines appear in the spectra from region C, due to interaction of the jet with water, depending on the water conditions and plasma operating parameters. These results declare that plasma jet interaction with water can be used as indicator for water quality and a detector for which species play the rule in plasma sterilization too.

We present the observation of a transit of the exoplanet TrES-3b by the newly commissioned robotic telescope TRAPPIST-North located at Oukaimeden Observatory (Morocco). The obtained light curve reaches a photometric precison 600 ppm. Its Bayesian analysis with a Markov Chain Monte Carlo code enables us to refine the radius of the planet to ${R}_{p}={1.346}_{-0.050}^{+0.065}{R}_{Jup}$. These results demonstrate the high potential of TRAPPIST-North for high-photometry of exoplanet transits.

The search and detection of extra-solar planets (exoplanets) have considerably improved over the past few decades. The launch of space observatories dedicated to exoplanets such as the Kepler mission and the wealth of publicly available data call for the development of efficient search methods. Here we present a search technique with a Graphical User Interface (GUI) to detect true exoplanets signals from Kepler data and filter out false ones using the optimal Box-fitting Least Squares (BLS) algorithm. The algorithm is used to detect transiting exoplanets from their light curves through searching for periodic flux variability of the host star. We present the results of the search to some Kepler catalog objects.

We present a new automated procedure that simultaneously derives the effective temperature T_eff, surface gravity log g, metallicity [Fe/H], and equatorial projected rotational velocity v_e sin i for stars. The procedure is inspired by the well-known PCA-based inversion of spectropolarimetric full-Stokes solar data, which was used both for Zeeman and Hanle effects. The efficiency and accuracy of this procedure have been proven for FGK, A, and late type dwarf stars of K and M spectral types. Learning databases are generated from the Elodie stellar spectra library using observed spectra for which fundamental parameters were already evaluated or with synthetic data. The synthetic spectra are calculated using ATLAS9 model atmospheres. This technique helped us to detect many peculiar stars such as Am, Ap, HgMn, SiEuCr and binaries. This fast and efficient technique could be used every time a pattern recognition is needed. One important application is the understanding of the physical properties of planetary surfaces by comparing aboard instrument data to synthetic ones.

An important phenomenon in Astrophysics is the process of magnetic reconnection (MGR), which is envisaged to understand the solar flares, coronal mass ejection, interaction of the solar wind with the Earth's magnetic field (so called geomagnetic storm) and other phenomena. In addition, it plays a role in the formation of stars. MGR involves topological change of a set of magnetic field lines leading to a new equilibrium configuration of lower magnetic energy. The MGR is basically described in the framework of the Maxwell's equations linked to Navier-Stockes equations. Nevertheless, many details are still not understood. In this paper, we investigate the MGR process in the framework of the Magnetohydrodynamic (MHD) model of a single conducting fluid using a modern powerful computational tool (OpenFOAM). We will show that the MGR process takes place only if resistivity exists. However, despite the high conductivity of the plasma, resistivity becomes effective in a very thin layer generating sharp gradients of the magnetic field, and thus accelerating the reconnection process. The net effect of MGR is that magnetic energy is converted into thermal and kinetic energies leading to heating and acceleration of charged particles. The Sun's coronal ejection is an example of the MGR process.

We provide a long epoch study of a set of solar and plasma parameters (sunspot number Rz, total solar irradiance TSI, solar radio flux SF, solar wind speed V, ion density n, dynamic pressure nV², and ion temperature T) covering a temporal range of several decades corresponding to almost four solar cycles. Such data have been organized accordingly with the interplanetary magnetic field (IMF) polarity, i.e. away (A) if the azimuthal component of the IMF points away from the Sun and T if it points towards, to examine the N-S asymmetries between the northern and southern hemispheres. Our results displayed the sign of the N-S asymmetry in solar activity depends on the solar magnetic polarity state (qA>0 or qA<0). The solar flux component of toward field vector was larger in magnitude than those of away field vector during the negative polarity epochs (1986-88 and 2001-08). In addition, the solar wind speeds (SWS) are faster by about 22.11±4.5 km/s for away polarity days than for toward polarity days during the qA<0 epoch (2001-08), where the IMF points away from the Sun. Moreover, during solar cycles 21^st and 24^th the solar plasma is more dense, hotter, and faster south of the HCS.

We study environment and host galaxy properties of powerful radio galaxies with different radio morphologies from compact sources to very extended double lobed radio galaxies and with different optical spectra classified as high excitation (HERG; quasar-mode) and low excitation (LERG; jet-mode) radio galaxies. We use a complete sample of morphologically classified radio sources from [1] and perform three different analyses: i) we compare compact radio sources with the extended sources from the same class of excitation. ii) we compare HERGs with the LERGs using a combined sample of compact and extended sources. iii) we investigate the origin of different morphologies observed in the very extended powerful radio galaxies, historically classified as Fanaroff-Riley (FR) radio galaxies of type I and type II by comparing a sample of FRIs with the FRIIs from the same excitation class. We discuss the results and what causes the differences in each comparison. The role of host galaxy and the central super massive black hole, and the galaxy interactions are all investigated.

TRAPPIST-North (TRAnsiting Planets and PlanetesImals Small Telescope) is a 60-cm robotic telescope that was installed in May 2016 at the Oukaimeden Observatory [1]. The project is led by the University of Liège (Belgium) and the Caddi Ayad University of Marrakech (Morocco). This telescope is a twin of the TRAPPIST-South telescope, which was installed at the ESO La Silla Observatory in 2010 [2]. The TRAPPIST telescopes are dedicated to the detection and characterization of planets orbiting stars other than our Sun (exoplanets) and the study of comets and other small bodies in our solar system. For the comets research, these telescopes have very sensitive CCD cameras with complete sets of narrow band filters to measure the production rates of several gases (OH, NH, CN, C₃ and C₂) and the dust [3]. With TRAPPIST-North we can also observe comets that would not be visible in the southern hemisphere. Therfore, with these two telescopes, we can now observe continuously the comets around their orbit. We project to study individually the evolution of the activity, chemical composition, dust properties, and coma morphology of several comets per year and of different origins (New comets and Jupiter Family comets) over a wide range of heliocentric distances, and on both sides of perihelion. We measure the production rates of each daughter molecules using a Haser model [4], in addition to the Afρ parameter to estimate the dust production in the coma. In this work, we present the first measurements of the production rates of comet C/2013 X1 (PANSTARRS) observed with TN in June 2016, and the measurements of comet C/2013 V5 (Oukaimeden) observed in 2014 with TRAPPIST-South.

We have undertaken a literature search for associations of gamma-ray bursts (GRBs) with supernovae (SNe), and we have constructed a much larger table of cases than has been published until now. The table contains a suite of physical properties for the GRBs (and the SNe when available), which will allow us and others to infer valuable knowledge about the GRBs and their physical mechanisms. From this basic table, we have undertaken a very preliminary examination, looking at the intrinsic GRB properties at hand, i.e. duration, isotropic energy output, peak spectrum energy, fluence, spectral index, redshift etc., and we present initial results. Future analyses will be performed to try to determine whether GRBs with no associated SNe constitute a subclass or category of bursts with particular characterizing properties.

We present a comparative study of atmospheric particulate matter (also known as aerosols) observed by satellite remote sensing and ground-based observations. We compare satellite measurements obtained by NASA's Moderate Resolution Imaging Spectro-Radiometer (MODIS) and Multi-angle Imaging Spectro-Radiometer (MISR) instruments against the ground-based aerosol sun-photometer data from the Aerosol Robotic Network (AERONET) station in Cairo, Egypt from 2003 to 2014 to build a long-term database for climatological studies and to improve upon the accuracy and coverage achievable from the satellite data. We deduce microphysical and geometrical properties about the dominant aerosols based on key optical properties including aerosol optical depth (AOD), single scattering albedo (SSA), and Ångström exponent (AE). This has allowed us to place important constraints on the type of aerosols (natural, anthropogenic, and biogenic).

Due to severe radiative energy losses during propagation, high-energy cosmic-ray electrons can reach Earth only from nearby sources. Although these sources clearly manifest themselves in the special features of the energy spectrum observed by recent space-borne experiments, especially the increase in the positron fraction, their exact nature is still a matter of debate. The standard method for interpreting cosmic-ray electron data consists in solving appropriate transport equations. It can be supplemented with a Monte Carlo approach taking advantage of the intrinsic random nature of cosmic-ray diffusive propagation. This analysis gives valuable information on the electron-by-electron fluctuations and hence allows to address the issue from a different angle. Here we show how to implement a fully three-dimensional time-dependent Monte Carlo simulation of the propagation of high-energy cosmic-ray electrons from nearby sources and discuss the "single-source" astrophysical scenario.

BeePol is an imaging polarimeter designed for the 60-cm telescope of the Farid & Moussa Raphael Observatory (FMRO) at Notre Dame University Louaize (NDU). It is based on the use of a Wedged Double Wollaston prism (WeDoWo), allowing for the simultaneous measurement of the I, Q, and U stokes parameters. When coupled to an Apogee Alta F42, 2k × 2k back illuminated, thinned, CCD camera, the polarimetric module allows for polarimetric imaging of a 1.25' × 10' field of view. Calculations done for the observing conditions at the FMRO show that the instrument may detect 1% polarization at 3σ for objects of magnitude 9, with an integration time of 1 hour. BeePol aims to serve as the prototype for an inexpensive imaging polarimeter of interest to small observatories.This paper reports on the basic design of the instrument, and ongoing work to build, test it, and start science observations.

The Farid & Moussa Raphael Observatory (FMRO) at Notre Dame University Louaize (NDU) is a teaching, research, and outreach facility located at the main campus of the university. It located very close to the Lebanese coast, in an urbanized area. It features a 60-cm Planewave CDK telescope, and instruments that allow for photometric and spetroscopic studies. The observatory currently has one thinned, back-illuminated CCD camera, used as the main imager along with Johnson-Cousin and Sloan photometric filters. It also features two spectrographs, one of which is a fiber fed echelle spectrograph. These are used with a dedicated CCD. The observatory has served for student projects, and summer schools for advanced undergraduate and graduate students. It is also made available for use by the regional and international community. The control system is currently being configured for remote observations. A number of long-term research projects are also being launched at the observatory.

Atmospheric pollution measurements from space have been evolving from low-earth-orbits (LEO) to geostationary orbits (GEO), to track the diurnal variation of atmospheric emissions. There are three GEO instruments in development. TEMPO is NASA's first Earth Venture Instrument, to be launched during 2018-2021. It will measure atmospheric pollution for greater North America using ultraviolet and visible spectroscopy. The European Sentinel-4 and the South Korean GEMS will measure atmospheric pollution for Europe and Southeast Asia, respectively. In this paper, we describe NASA's TEMPO instrument and we propose a similar instrument in GEO to provide hourly atmospheric pollution measurements for the Middle East at very high spatial resolution. The proposed Middle-East TEMPO instrument will cover Arab Countries, and parts of Asia and Europe. The measurement will include the spectra required to retrieve O₃, NO₂, SO₂, H₂CO, C₂H₂O₂, H₂O, aerosols, cloud parameters, and UVB radiation.

Most Active galactic nuclei (AGNs) are obscured by large column densities of cold and neutral gas. If the X-ray obscuring matter has a column density equal to or larger than the inverse of the Thomson cross-section (N_H ≥ σ_T ≈ 1.5×10²⁴ cm^-2), then the source is identified as a Compton-thick AGN. One of the characteristics of Compton-thick AGN is the presence of Fe K⍺ emission line in their spectra with a large equivalent width. Using this criterion with XMM-Newton observations we identified Compton-thick AGNs by following a selection method, the FLEX algorithm, developed by Maccacaro et al [1] to search for X-ray line emitting objects (XLEOs). This technique detects the sources having significant excess of photons resulting from the iron emission line. Here we present the results from applying this method on the 28 highly absorbed AGNs recently detected by Corral et al [2]. Of these 28 AGN, 15 are candidate Compton-thick AGN. We applied the detection algorithm on a pilot sample of 40 XMM-Newton observations. Our results confirm the Compton-thick nature of 14 of Compton-thick AGN, based on the observed properties of the Fe Kα emission line. We use the characteristics of the observed lines to diagnose the AGNs and their environments.

NGC 147 and NGC 185 are two of the most massive satellites of the Andromeda galaxy (M 31). With similar mass and morphological type dE, they possess different amounts of interstellar gas and tidal distortion. The question therefore is, how do their histories compare? We present the first reconstruction of the star formation histories of NGC 147 and NGC 185 using long-period variable stars (LPVs). LPVs are low- to intermediate-mass stars at the asymptotic giant branch, which their luminosity is related to their birth mass. Combining near-infrared photometry with stellar evolution models, we construct the mass function and hence the star formation history. For NGC 185 we found that the main epoch of star formation occurred 8.3 Gyr ago, followed by a much lower, but relatively constant star formation rate. In the case of NGC 147, the star formation rate peaked only 7 Gyr ago, staying intense until ∼ 3 Gyr ago, but no star formation has occurred for at least 300 Myr. Despite their similar masses, NGC 147 has evolved more slowly than NGC 185 initially, but more dramatically in more recent times.

We present the observation of line doubling absorption in the spectra of the RR Lyrae variable star on the metal lines of FeII (λ = 4923.921Å) as well as of D1 and D2 lines of sodium. For the emission, we observed the lines of hydrogen H_α and H_β with a very high intensity and the two lines of HeI (λ = 5875.66 Å and λ = 6678.15Å). This transmission/helium I remission [1, 2] is directly related to the intensity of the shock wave through the atmosphere of the star during the phase of maximum Blazhko cycle [3]. During the expansion phase of the photosphere of the star and during the passage of the shock wave we witnessed a disappearance of the absorption lines of neutral FeI (λ = 4934.006Å and λ = 4920.503Å) and their reappearance in phase 1.00. These observations were made with a spectrograph resolution scale of about 12,000 installed on the C14 telescope at the Oukaimeden observatory (J43) during the different star pulsation cycle. We noticed that some of them almost coincide with the maximum Blazhko cycle. The doubling line were interpreted by Schwarzschild [4] on the basis of a two-layer atmosphere. This interpretation could measure the speed of the shock wave derived from the difference between the two red and blue spectral components on H_α hydrogen lines, D3 helium, D1 and D2 lines of sodium and FeII during the observed doubling of lines. At phase 1.00, the shock wave reached the maximum speed of 160 km.s⁻¹ confirming the hypersonic regime occur during this maximum Blazhko cycle.

Space plasmas studies on bow shock dynamics and structure scales continue to attract intense theoretical and experimental investigations. The Earth's bow shock is the closest shock accessible to scientists through various satellite missions. These missions have enabled investigations on different physical phenomena associated with solar-terrestrial interaction. Access to the interplanetary medium through satellites has provided access to valuable spatial and temporal data on the Earth bow shock, and has furthered understanding on certain aspects of shock physics that were inaccessible until now. The main objective of this study is to quantify the dynamics and structure scales of the Earth's bow shock using data obtained by the MMS multi-spacecraft during shock crossing.

This paper investigates the progenitors of Millisecond Pulsars (MSPs) with a distribution of long orbital periods (P_orb > 2 d), to show the link between white dwarf (WD) binaries and long orbits for some binary MSPs through the Accretion Induced Collapse (AIC) of a WD. For this purpose, a model is presented to turn binary MSPs into wide binaries and highly circular orbits (e < 0.1) through the asymmetric kick imparted to the pulsar during the AIC process, which may indicate a sizeable kick velocity along the rotation of the proto-neutron star. The results show the effects of shock wave, binding energy, and mass loss (0.2M_⊙). The model shows the pulsar systems are relevant to AIC-candidates.

The production of the light elements in the framework of the standard Big Bang nucleosynthesis model (SBBN) matches the observed abundances except in case of ⁷Li, where observations lie a factor 2.4-4.3 below SBBN+WMAP(Wilkinson Microwave Anisotropy Probe) predictions. This so-called "Lithium problem" needs to be resolved beyond the SBBN. In this contribution we focus on the effect of degenerate neutrinos and the addition of dark component, including dark energy density and dark entropy. We find that the effect of the degeneracy parameter is significant if chemical potentials of neutrino families are different. Concerning the dark component, the major effect comes from adding dark entropy.

In our research, we studied the characteristics of two newly discovered open star clusters. Their structural (core radius, limiting radius, etc) and the astrophysical parameters (reddening, distance, age, etc) have been investigated using 2MASS database and PPMXL database extracted from VizieR web site for the studied clusters. The studied newly discovered clusters are SAI 19 and SAI 23 were not studied before, they have ages of 0.4 Gyr and 0.3 Gyr respectively. The luminosity and mass functions as well as the total masses have been determined.

Berkeley 17 is known to show a core-tail morphology. Pan-STARRS 1 photometry complete to g_P1 ≈ 21.5 mag reveals the effect of mass segregation between the core and the tail (and an antitail). Furthermore, there is an overall paucity of low-mass member stars — likely as the consequence of tidal stripping by the foreground Perseus arm of this aged (10 Gyr) cluster. Our analysis indicates that about half of the blue straggler candidates suspected to be associated with Berkeley 17 may be field contaminations, and yet some may be confused with blue horizontal-branch stars usually found only in globular clusters. We propose Berkeley 17 to be a remnant super star cluster in the continuing process of disintegration.

Planetary plasma and atmospheres have been challenged by space missions of Japanese science community from 1990s, with ISAS and JAXA. The first trial, a Martian orbiter Nozomi, was launched in July 1998. At the departure from Earth in Dec. 1998, she met an engine trouble but we struggled and found a narrow and long path connecting to the Dec 2003 arrival, which is the simultaneous arrival with ESA Mars Express. Unfortunately, we had an additional power trouble in Apr. 2002 associated with a solar flare event, and we gave up the trial at the gate of Mars in Dec. 2003. In parallel to the Kaguya Lunar orbiter in 2007-2009, a next trial to planets, the Akatsuki orbiter to Venus, was prepared. She departed from Earth in May 2010. However, she got an engine trouble at the arrival to Venus in Dec. 2010, and we again endured another long path, but this road was at last ended by a success of the orbit entry in Dec. 2015. We also created the UV/EUV space telescope, Hisaki, using the sensor and optics technologies extracted from Nozomi. It is going well after the launch in 2013 and actively looking planetary thin atmospheres collaborating with other space missions. This paper summarizes the Hisaki and Akatsuki missions which are now on orbit, with the next missions, Arase (ERG), BepiColombo, JUICE, and beyond.

The ERG (Exploration of energization and Radiation in Geospace) is Japanese geospace exploration project. The project focuses on relativistic electron acceleration mechanism of the outer belt and dynamics of space storms in the context of the cross-energy coupling via wave-particle interactions. The project consists of the satellite observation team, the ground-based network observation team, and integrated-data analysis/simulation team. The satellite was launched on December 20 2016 and has been nicknamed, "Arase". This paper describes overview of the project and future plan for observations.

We report an experimental study of the intracrystalline distribution of Fe²⁺ and Mg between the non-equivalent octahedral sites, M1 and M2, in orthopyroxene from the Kapoeta meteorite by single-crystal X-ray diffraction and Mössbauer spectroscopy. The Fe²⁺-Mg ordering closure temperatures obtained by X-ray structure refinement for two orthopyroxene crystals from Kapoeta (357±30 °C and 411±18 °C) are very similar to those reported for diogenites, and indicate a slow cooling rate. The powder Mössbauer spectra of the light and dark regions in Kapoeta are identical, and their hyperfine parameters are characteristic of orthopyroxene. The closure temperature obtained by Mössbauer spectroscopy for the Kapoeta orthopyroxene (744 °C) is rather high, and indicates a fast cooling rate. The results are discussed in connection with the thermal history of the Kapoeta parent body.