We consider a new effective symmetry that acts on a gauge invariant Lagrangian. We show that the standard model after spontaneous symmetry breaking is invariant under this symmetry which identifies up to a scale factor the gauge parameter with the elementary or composite scalars in the theory. We discuss some of the consequences of this symmetry in the abelian and non-abelian sectors of the standard model.

The instability of an entropic dynamical model is considered via Jacobi vector field and the Lyapunov exponent. From the viewpoint of information geometry, geometric structure of the statistical manifold underlying this model is investigated, and we conclude that it is a manifold with constant negative scalar curvature. By use of the Jacobi vector field associated with the geodesics, we study the asymptotic behavior of the geodesic spread on the statistical manifold and reach that it is described by an exponentially divergent Jacobi vector field with respect to time. A positive Lyapunov exponent is also obtained, that explains the local instability of the system as well. Furthermore,submanifolds are studied similarly.

In this work we discuss different measures aimed to characterize the folding mechanism which together with the stretching process determine the chaotic dynamics. We show that from a study of the evolution of the distance between two trajectories beyond the exponential stage until the asymptotic regime is possible to obtain a quantity which provide an insight about this mechanism and its dependence on the control parameter. The asymptotic mean distance $d_{\infty}$ manifests a specific power law dependence at the transition to chaos and is quite complementary to Lyapunov exponent in characterizing the chaotic motion. Then based on the methods of inverse statistics applied to one-dimensional maps we advance an alternative measure able to reflect the folding mechanism on the strange attractors. In the final part we argue briefly that the inverse statistics can be a relevant tool to the study of earthquakes produced in the Vrancea region.

We describe the time evolution of logarithmic negativity, which gives the entanglement strength of two-mode Gaussian states in terms of the covariance matrix, for a system of two bosonic modes each one interacting with its thermal reservoir. We take the squeezed thermal states as initial states and show that at a definite moment of time the suppression of entanglement (entanglement sudden death) takes place for all nonzero temperatures of the thermal baths. For zero temperature of both thermal reservoirs, an initial entangled squeezed thermal state, in particular a squeezed vacuum state, remains entangled for all finite times, but in the limit of infinite time the state becomes separable.

In the present paper, approximate solutions of fractional Poisson equation (FPE) have been considered using an integrator in the class of Lie groups, namely, the fictitious time integration method (FTIM). Based on the FTIM, the unknown dependent variable $u(x, t)$ is transformed into a new variable with one more dimension. We use a fictitious time $\tau$ as the additional dimension (fictitious dimension), by transformation:
$v(x, t, \tau ) := (1 + \tau )^{\kappa} u(x, t)$, where $0 < \kappa \le 1$ is a parameter to control the rate of convergency in the FTIM. Then the group preserving scheme (GPS) is used to integrate the new fractional partial differential equations in the augmented space $\mathbb{R}^{2+1}$. The power and the validity of the method are demonstrated using two examples.

In this paper, a new shifted ultraspherical wavelets operational matrix of derivatives is introduced. The two wavelets operational matrices, namely Legendre and first kind Chebyshev operational matrices can be deduced as two special cases. Two numerical algorithms based on employing the shifted ultraspherical wavelets operational matrix of derivatives for solving linear and nonlinear differential equations of Lane-Emden type are developed. The main idea for obtaining the presented algorithm is essentially based on reducing the linear or nonlinear equations with their initial conditions to systems of linear or nonlinear algebraic equations, which can be efficiently solved. Some numerical examples are given to demonstrate the validity and the applicability of the algorithms.

We develop a family of improved iterative formulas for computation of matrix inverses. Towards this purpose, we first consider a general class of scalar Newtontype root-finders, which have been improved by incorporating the Adomian decomposition method. Subsequently, we extend such scalar root-finders to their respective matrix analogs by means of an innovative computer screening program. Our formulas are shown, through numerical experiments, to surpass five well-known iterative schemes taken from the literature, both in terms of the CPU elapsed time and iteration count. According to these results, one of our new formulas saves more than 13% in CPU time in the worst case, when compared with all five previous iterative methods. In addition, the convergence order of a simple member of the family of our matrix inversion formulas was proven to be at least three to better elucidate our new approach.

Symmetry analysis of a wave equation on a class of cylindrical symmetric static space-times (CSSS) is performed. The results are classified according to the Noether symmetries and metrics spaces. Symmetry algebras are found in flat metrics and in non-flat background metrics. It turns out that the wave equation on these metrics admit strict (zero gauge) Noether symmetry groups of dimension 5, 6, 7, 8 and 12. Conserved
forms for the wave equation are constructed by the application of Noether’s theorem.

This paper studies Kadomtsev-Petviashvili equation with spatio-temporal dispersion and power law nonlinearity. There are several approaches adopted to integrate the equation and display a large spectrum of solutions. These integrability approaches are modified $F$-expansion, exp-function method, $G’/G$-expansion method, functional variable algorithm, first integral approach, traveling wave hypothesis, and semi-inverse variational principle. The solutions that are recovered by using these approaches carry respective constraint conditions that must remain valid for the solutions to exist.

In this paper the Lie symmetry analysis is performed on the quantum Zakharov equations that describe the interaction between Langmuir waves and ion-acoustic waves in an electron-ion dense quantum plasma. The similarity reductions and some exact solutions with the aid of sub-equation method are obtained based on the optimal system of one-dimensional subalgebras for the quantum Zakharov equations. In addition, the conservation laws of the quantum Zakharov equations are also constructed using the direct (multiplier) approach.

In this study, the modified simple equation method is used to construct exact solutions of the space-time fractional modified Korteweg-de Vries equation, the spacetime fractional modified regularized long-wave equation and the space-time fractional coupled Burgers’ equations in mathematical physics. The exact solutions obtained by the proposed method indicate that the approach is easy to implement and computationally very attractive. Also we can see that when the parameters are assigned special values, families of exact solitary wave solutions can be obtained by using this method.

In this paper, we investigate the modified Korteweg-de Vries-Zakharov-Kuznetsov and the Hirota equations and obtain exact travelling wave solutions by using Jacobi elliptic function expansion method together with the symbolic computation system Mathematica. For some limit cases, the obtained periodic solutions degenerate to the corresponding solitary wave solutions and other types of solutions.

In this paper, we apply the extended ($G'/G$)-expansion method to construct exact solitary wave solutions, topological solitons, and singular solitons of Bogoyavlensky-Konoplechenko (BK) and Jaulent-Miodek (JM) nonlinear evolution equations.

Chaos synchronization of permanent magnet synchronous motor (PMSM) has been central to recent experimental and theoretical investigations. In existing papers, the implementations of synchronization control require the system states for feedback, which are effective but unacceptable in practical application. In this paper, an output feedback controller is proposed for synchronization of PMSM based on the theory of passive control. Theoretical analysis shows that the control method makes the synchronization error system between the driving and the response motor systems not only passive but also asymptotically stable. Numerical simulations are provided to verify the effectiveness of the proposed scheme.

Perpendicular, parallel and effective moments of inertia are calculated for deformed doubly even actinide nuclei ranging from Thorium up to Fermium ($226 \le A \le 256$) within the Belyaev cranking-model and by using the single-particle energies and eigenstates of a deformed Woods-Saxon mean field. Calculations had been performed systematically for the ground state, for the second and third minima as well as for the first, second and third saddles points associated with fission isomers. The evolutions of the different momenta of inertia and their dependence on excitation energies as well as on deformations is shown. Comparisons with experimental values, when available, is made.

The fragmentation potential for all mass asymmetries is evaluated at an excitation of 30 MeV. The isomeric minima observed for the adiabatic energy surface are still present but their wells are attenuated. The fast fission mass yield distributions were evaluated from these isomeric minima at 30 MeV excitation energy and are found consistent with experimental data.

We report on the OpenMP parallelization of a Fortran-based Boltzmann-Vlasov code that is of interest to the experiments at ELI-NP, specifically for the interpretation of results concerning the excitation of pygmy and giant dipole resonances. We show that the optimized codes can be successfully employed to obtain in reasonable running times physically relevant results for the dynamics of such collective modes. The current results can serve as a starting point for future computational investigations into fusionfission dynamics, also of interest at ELI-NP.

We theoretically reformulated non-relativistic angular and energy distribution of ejected photoelectron in the frame of the Ammosov-Delone-Krainov (ADK) theory for a linearly polarized laser field. The influence of the ponderomotive potential and the Stark shift on tunneling transition rate was considered. It is shown that these effects influence on behavior of the angular and energy spectrum as well as on the energy spectrum’s width. Dependence of the angular and energy distribution from a spatial laser beam profile (Gaussian and Lorentzian) is discussed, as well as longitudinal and perpendicular width of photoelectron energy spectra.

Very recently the spinodal curves of some water(1)-1-alkanol(2)-1-propanol (3) systems that present a Type I solubility gap (1-alkanol = 1-butanol, 1-pentanol,1-hexanol) have been calculated by using the Generalized Wheeler-Widom-Huckaby model with a local fitting procedure which requires, as input data, the experimental coordinates of the plait point. Because the experimental plait point position can be affected by a significant error, we tested in this paper the effect of changing artfully the location of the plait point on the final position of the spinodal curve.

We have investigated the possibility of using graphyne nanotubes for NO$_2$ detection by using density functional theory. The zigzag nanotubes based on $\alpha$-graphyne are studied. The adsorption distance, adsorption energy, charge transfer, electronic band structures and density of states are calculated. The large adsorption distance and small adsorption energy indicate NO$_2$ molecule is adsorbed on graphyne nanotubes via physisorption. The zigzag graphyne nanotubes with semiconducting properties become p-type semiconductors with NO$_2$ adsorption. The sensitivity of the electronic properties of graphyne nanotubes to the presence of NO$_2$ indicates these nanomaterials are proper for NO$_2$ detection.

We report a preliminary study on four orthodontic cements, including three glassionomer cements and a zinc-phosphate cement, carried out by thick target X-ray fluorescence (XRF) using a portable spectrometer. The aim of this study was to assess the potential of this method for the analysis of some biomaterials used in orthodontics. Due to the lack of reference materials and thick target nature of samples, and because most of the analyzed materials evidenced only one major element, only qualitative analysis was performed. The analyzed glass-ionomer cements unexpectedly evidenced Sr and La as major elements. Two of the analyzed glass-ionomer cements containing Sr also contained traces of Au, and they showed almost identical compositions. The materials contained in addition traces of Fe, Co and Zn. The roles of the detected elements are discussed. While XRF proved to be a valuable and simple method for the diagnosis of substituted glass ionomer cements, other analytical techniques should be used for more advanced characterization.

Using a portable spectrometer, we performed a preliminary standardless X-ray fluorescence (XRF) analysis of four endodontic repair materials. The potential of this simple and versatile method was evaluated in comparison with other more powerful techniques used previously. Thick target analysis of endodontic cements provided relative concentrations with an accuracy better than orders of magnitude. In addition to Ca and Fe, the spectra evidenced Zr and Bi as major elements and La and Au as minor elements. Zr, Bi, La and Au were embeded in the materials in order to make them more opaque to X-rays than the tooth. Probably, La and Au were sintered with ceramo-metallic glass microparticles. Zr was accompanied by its chemical analogue Hf. While XRF proved to be complementary to other methods, further studies of endodontic repair materials will be needed to follow the fate of Bi and La due to their significant chemical reactivity and low to moderate level of toxicity.

Electron spin resonance (ESR) studies were carried out on 5 types of organic tea cultivated in Romania: Mentha piperita, Hypericum perforatum, Achillea millefolium, Rhamnus frangula, Calendula officinalis and the results compared with commercial Twinnings black tea. In function of tea type, spin centers like Mn$^{2+}$ bounded and unbounded by proteins, Fe$^{3+}$ and Cu$^{2+}$ were evidenced. Dry tea leaves show additional sharp line attributed to semiquinone radical which disappeared in tea drinks. The origin of the spin species in analyzed tea leaves and drinks are defined and discussed. The evaluation of antioxidant capacity of analyzed tea drinks was based on measuring the changes of ESR spectrum of radicals as a result of their interaction with antioxidants. The Mentha piperita and Hypericum perforatum tea exhibit an important scavenging activity. In the case of Mentha piperita the scavenging activity is comparable with that of black tea.

A numerical method is presented to study the laser beam distortions and their influence on the interference patterning after propagation through an optical chirp pulse amplification (CPA) system. This study is based on numerical simulation using the ray-tracing model from Optica module of MATHEMATICA and it relates the behavior of the distorted beam in terms of spatial distortions in case of user-induced misalignments in single-grating stretcher-compressor system. It was shown that this effect can be used both to control the femtosecond laser interference pattern design and to improve the quality of the CPA beam profile for ultra-fast micro and nanopatterning experiments using multiple CPA laser beams.

Optical components (lens, mirrors, filters, prisms, etc.) can be exposed to energetic photons such are gamma-rays when used in either outer space or nuclear applications. The study of the behavior is important to avoid failure of these samples, during operation. The optical spectral reflectance and transmittance for multi-layer coating substrates laser mirrors, exposed to ten $^{60}$Co gamma-rays doses ranging between (0.04÷21) kGy, have been investigated. The optical parameters of samples were measured, before and after gamma irradiation, to highlight the changes and the influence of gamma-absorption on spectral measurements. The ten samples have been investigated via spectral reflectance and transmittance, for the wavelengths range (400-800) nm. Some variations of optical properties have been detected in BK-7 glasses (substrate) after irradiation.

The detailed description of the thermionic vacuum arc (TVA) method and its uses in both simultaneous and alternate thin film deposition is presented. The TVA is an original plasma processing method for growth of thin films which consists in igniting a plasma in the vapors of the solid precursor which represents the anode by bombardament with thermo-emitted electrons from an electron gun under high vacuum conditions. The potential variation between 50 V and 800 V of the TVA discharge with the interelectrodic gap of 2-14 mm was measured by means of thermal-emissive probe. Using two or more solid precursors, Co-Cu composite and multilayer structures were be obtained in simultaneous or alternate discharges. Insulating layers as SiO, MgO, MnO were also prepared when only dc current was used.

Optical emission spectroscopy (OES) in a flowing afterglow of a methanol/ethanol ($10^{-4}\div 10^{-3} \%$) - N$_2$ D.C. plasma was the used method in order to measure carbon atom concentration. From the intensities of the nitrogen first positive system and the CN radical violet bands, and by means of a kinetics mechanism, the C atom concentration was found to be in the range $2\div 6 \times 10^{11}$ cm$^{-3}$ for nitrogen-methanol and $7\times 10^{11}\div 6\times 10^{12}$ cm$^{-3}$ for nitrogen-ethanol mixtures respectively, at pressures between $1\div 6.66$ mbar. The calculated carbon atoms density was established to be one order of magnitude bigger in the case of the ethanol-nitrogen mixture than in the one of methanol-nitrogen.

This work reports on the synthesis of polythiophene-like thin films by using a post-discharge RF plasma configuration in which thiophene vapors are introduced in the substrate proximity. The deposition process is assisted by a controlled iodine flow for in-situ doping leading to a material with improved conductivity. The influence of iodine mass flow rate on the deposition rate, optical parameters, composition, chemical structure and electrical properties of the material obtained in various discharge conditions is reported.

Two systems for egg treament with cold atmospheric plasma are presented. Plasma is produced in dielectric barrier discharges, which are supplied by AC or pulsed high voltages. Gas composition, voltage/current waveforms, dissipated power in plasma, gas temperature, ozone production, treatment times, are presented and discussed.

Modern trends in civil construction are based on increasing the energy efficiency of buildings in which we live. But unfortunately efficient insulation of buildings and the introduction of air conditioning systems and other architectural and energy-efficient technologies lead to elevated indoor radon levels and other chemical pollutants. In this paper the assessment of population exposure to radon in energy efficient buildings was studied. To investigate indoor radon levels in the modern buildings the measurements were performed in 25 energy efficient houses constructed in the last decade by using mostly solid concrete or gas-concrete blocks, by using nuclear track detectors CR-39 exposed for 6-7 months on inhabited area of dwellings, according to the NRPB Measurements Protocol. The overall concentration levels of the indoor radon in the 50 studied rooms varied from 18 to 593 Bqm$^{-3}$ with a mean of 160 Bqm$^{-3}$. This value is 27% higher than the average reported by authors for conventional homes in Transylvania, Romania.

The aim of this study was to record the indoor radon concentrations and its seasonal variation in 25 dwellings in Athens. The experiment was undertaken between 2013 and 2014, for three seasons (spring, summer, winter) of three months each. CR-39 solid state nuclear tracks detectors were used to measure the indoor radon levels. The indoor radon concentration showed a variation between 23 and 189 Bq/m$^3$ during the spring, from 42 to 186 Bq/m$^3$ in the summer and from 79 to 245 Bq/m$^3$ in the course of winter. These results highlight a radon seasonal variation following the pattern: a higher concentration in the winter (137.5 Bq/m$^3$) than in the summer (96.10 Bq/m$^3$) and spring (54 Bq/m$^3$).

Building materials are significant contributor of indoor radon after the soil. The indoor radon level depends upon the radon flux coming out from wall, ceiling and roofs of the dwellings. The radon flux from the wall that in most cases is concrete depends upon many factors like radium content, porosity, moisture, composition of mix design for construction of concrete and age of concrete. The present work is a study of effect of various factors on the radon exhalation rate from concrete. The measurement of radon exhalation rates from the concrete was determined by active technique using continuous radon monitor. The results show that the radon exhalation rate decreased with decrease of porosity of concrete and increase of moisture content after a particular value. The various additives like silica fume and fly ash may cause the decrease of radon exhalation up to optimum value, after that it increases. The radon exhalation rate also varied with age of concrete.

The Baita-Bihor National Repository for Low and Intermediate Waste Disposal (Bihor County, Romania) is located in the homonymous decommissioned Uranium mine. Therefore, a correct evaluation of the radiological impact on workers and operators is of utmost importance.
After a six month monitoring of the dose rate distribution within the repository corridors, performed by means of 20 TLD passive detectors (10 environmental $\gamma$ and $\beta$ rays and 10 albedo neutron), the dose rates varied between 107 and 269 nSv/h in the case of $\gamma$ and $\beta$ rays and reached a maximum of 5 nSv/h in the case of neutrons, giving an annual value of $1.6 \pm 0.3$ mSv. These results, consistent with an environment presenting traces of uranium ore and radon, are analysed and discussed within the Romanian National Norms of the radiological safety.

This paper describes an online instrument with multiple purposes developed to complement the functionality of a mobile laboratory employed in the field of Conservation - Restoration of Cultural Heritage. The instrument was developed as a web-based platform using common web design technologies. The platform can be used for the online access to infrastructure of the mobile research laboratory like real-time monitoring, teleoperation of certain devices, results and reports database or realtime communication with remote researchers regarding specific investigation tasks on field. It is also the base support for specialized online courses, tutorials and demonstrations for students coming from archaeology, art conservation studies or technical fields.