Research Trends and Challenges in Physical Science Vol. 7

Using the solution casting method, various compositions of nanocomposite polymer electrolyte (NCPE) films were successfully synthesised, including  Polyvinylideneflouride-co-hexafluoropropylene (PVDF-HFP) as a host, Magnesium chloride (MgCl₂) as an ionic salt and various concentrations of nanosized ceramic fillers -TiO₂, MgO, ZnO and Al₂O₃. Effect of dispersion of various ceramic filler in SPE on ionic conductivity of SPE has been discussed. The best bulk conductivity (\(\sigma \)) achieved at room temperature for optimum conducting composition (OCC) of solid polymer electrolyte is 4.69x10^-7 S/cm-phase-I^st. Further on addition of filler-phase II^nd, conductivity increased and achieved highest for composition i.e. PVDF-HFP: MgCl₂: ZnO (70:30:3) of NCPE is 1.25x10^-5 S/cm and from temperature dependence study we got highest \(\sigma \) for OCC of NCPE at 110 ⁰C is 1.24x10^-4 S/cm. Impedance Spectroscopy was used to measure the electrical properties of all samples in the frequency range 42Hz-5MHz and the temperature range 30 -110⁰C. To characterise the structural properties of these NCPE films, X-ray Diffraction (XRD) was used. The ion transport number t_ion \(\sim\)0.99 for OCC of NCPE system obtained by Wagner’s dc polarization technique.

This research clarifies a mechanistic insight into Oxidative Degradation of Favipiravir by Electrogenerated Superoxide through Proton-Coupled Electron Transfer. Electrochemical analyses aided by density functional theory calculations were used to investigate the oxidative degradation of pyrazine antiviral drugs, 3-hydroxypyrazine-2-carboxamide (T-1105) and 6-fluoro-3-hydroxypyrazine-2-carboxamide (favipiravir, T-705), by the electrogenerated superoxide radical anion (O₂^\(\cdot\)-). T-1105 and T-705 are antiviral RNA nucleobase analogues that selectively inhibit the RNA-dependent RNA polymerase. They are expected as a drug candidate against various viral infections, including COVID-19. The pyrazine moiety was decomposed by O₂^\(\cdot\)-through proton-coupled electron transfer (PCET). Our results show that its active form, pyrazine-ribofuranosyl-5'-triphosphate, is easily oxidized under inflamed organs by overproduced O₂^\(\cdot\)- through the PCET mechanism in the immune system. This mechanistic study implies that the oxidative degradation of pyrazine derivatives will be prevented by controlling the PCET through simple modification of the pyrazine structure.

The paper considers the superliner photovoltaic effect associated with the modification of heterojunctions of the pCu₂S-nSi type by introducing a silicon nanocluster subsystem into it at the junction boundary. The design of a photocell containing two sequentially articulated p-n junctions of counter action, photoactive in different regions of the spectrum, is proposed. We show that film heterojunctions, which include a nanocluster subsystem, have a difference from the non-clustered version. Heterophotocells without nanocluster subsystem always have sublinear, or, in rare cases, linear lux-ampere characteristics (up to illumination \(\sim\) 5 10⁴ lx), while because of introducing nanocluster centers into the base p-region of the Cu₂S-Si heterojunctions, a significantly higher integral sensitivity is achieved at high illumination of the samples in the mode of a valve photocell. At an increase in the size of NC centers to hundreds and more angstroms, the photoeffect is not only not enhanced, but, on the contrary, completely disappears, giving way to a new effect of superlinearity of the lux-ampere characteristic. The discovered superliner photoeffect in a heterophotocell based on an NCS leads to an increase in the cell photosensitivity at high illumination.

The paper presents that the total measurement error is treated as a random process in time where the error is structurally decomposed into three groups due three different sources. The first group contains time variable errors due to tropospheric-ionospheric influences,\(\alpha\) , the second one time variable errors due to quasi-stationary refraction blocks, \(\beta\), whereas the third group contains purely random errors - random process noise. In the paper it is claimed that these two groups of time dependent errors determine  the accuracy of the GPS measurements, i. e. that they are two principal components of the GPS measurement variances.

The aim of this paper is to discuss some theoretical possibilities for engineering multifunctional nanomaterials. The discussions are founded on calculations previously performed for 1D and 2D nanomaterials within the Hubbard model (HM). The main results of the HM are briefly reviewed. The conclusion is that the approach taken in this paper is a distinct improvement over those in the literature.In the present paper results of applications of the (HM) are directly used in examples of engineering nanomaterials. On the other hand, in the literature calculations were performed by ab initio methods and then fitted to the form of the Hamiltonian of the (HM). It was shown on several examples that it is possible to engineer multifunctional nano-materials by calculating their conductivity, reflectivity and sensitivity for piezoresistivity, making calculations within the Hubbard model a viable way in theoretically modelling nanomaterials.

The Electric Reduced Transition Probabilities B(E2)\(\downarrow\) have been estimated for the even neutron numbers of \(^7{^2}{^-}{^7_3}{^8_2}Ge\) isotopes using the Interacting Boson Model-1 (IBM-1). The U(5) symmetry, B(E2)\(\downarrow\) values, intrinsic quadrupole moments and the deformation parameters for even neutron number, N = 40-46 of the \(^7{^2}{^-}{^7_3}{^8_2}Ge\) isotopes have been studied. The R_4/2 values for the even-even \(^7{^2}{^-}{^7_3}{^8_2}Ge\) isotopes also have been calculated for the first 4⁺ and 2⁺ energy states through the investigation for the dynamic symmetries U(5), SU(3) and O(6). From this investigation, the R_4/2 values are obtained less than 2 and, thus U(5) limit is identified.

The Fokker-Planck equation depicts the evolution of Brownian particle probability density over time. Many real-world problems in physics, biology, chemistry, and engineering are modelled using defferential equations. In non-equilibrium thermo-dynamics, the energy generation and energy production approach has been very important tools in describing systems. We have written a brief review on both these methods and explained the connection with Fokker-Planck equations with the entropy generation and entropy production method. The principles of statistical physics allow a connection between the Fokker-Planck equations and the different entropy approaches. Our future work will be to apply the Fokker-Planck equations and the enytropy approaches to systems which exhibit a non-equilibrium physics behavior.

The subject of this paper concerns a GPS measurement method by which a maximum measurement accuracy is achieved, but with a minimum cost of all works, i. e. an optimal solution for the GPS measurement process is proposed. Besides, for the first time the formulae for calculating the measurement accuracy of planned GPS base vectors are given.

This article shows that the mainstream discussion about super-quantum correlations is skewed by an incorrect interpretation of the “no-signaling” condition (NS). Referring to counter-examples, it shows that the usual probabilistic interpretation of (NS), whose link with relativistic causality is doubtful, is too weak to assert the absence of any exchange of information between the parties. A relevant informal interpretation of (NS) is nothing but a particular specification of Pawlowski’s Information Causality principle, which rules out the possibility of correlations stronger than the strongest quantum correlations.

The MHD flow of dusty fluids through channels is very critical from an industrial standpoint because molten metals are passed through channels to shape them into various forms, and oil refineries require knowledge of such flows. The objective of this paper is to determine the effect of volume fraction of dust on the flow of Magnetohydrodynamics flow between two parallel plates. In light of this, the motion of an incompressible dusty fluid with uniform distribution of dust particles between two parallel plates under the influence of a uniform transverse magnetic field has been investigated. Following the formation of equations based on well-established theories, they were solved under the assumed conditions, and the effect of various parameters associated with the flow problem was analysed using graphs. The velocities of fluid and dust particles are observed to reduce as the magnetic field is increased.

Discrete topological dynamical systems are given by the pair (X,f) where X is a topological space and f:X\(\rightarrow \)X a continuous maps. During years, a long list of results have appeared to understand and give sense to what is the complexity of the systems. Among others a useful tool and one of the most popular is that of topological entropy. The phase space X in most applications is a compact metric space. Even other conditions on X and f have been considered. For example X can be non-compact or f can be discontinuous (only in a finite number of points and with bounded jumps on the values of f or even unbounded jumps). Such systems are interesting from theoretical point of view in Topological Dynamics and by applications in applied sciences such as Electronics and Control Theory.

In this paper we are dealing with entropies. We start with the original ideas of entropy in Thermodinamics and their evolution until the appearing in the twenty century of the notions of Shannon and Kolmogorov-Sinai entropies and the subsequent notion inspired on them of topological entropy. In the mathematical setting such notions have evolved apppearing extended versions to cover recent problems.

we proposed a new concept of “cold electron” in order to reveal the nature of superconductivity. A new quantum theory of cold electron was proposed to explain superconductivities and compensate for the lack of present theory. The key point is that we accepted the concept of electron orbital rotation instead of traditional electron spin. It leads to an important conclusion that the electron at low temperature is running in a flat orbital. The physical mechanism of superconductivities is so explained preferably. Under the assumption that the electrons have their motion tracks and the tracks can be described in atoms, the situations of electron will be changed a lot. The new concept of cold electron is then established. It means that the electrons can feel temperature. The Schrödinger function is the function of ideal electron indeed. Hot electron looks like the electron of the ideal electron. As temperature goes much lower, the electron orbits will obviously departure to what Schrödinger function described, and run in a flat one. Temperature changes the orbital geometry of paired electrons, shifting from three to two dimensions. When compared to the common electron's orbital form, the paired cold electron saves a lot of space in the atomic crystal lattice. It set the stage for the phase change to occur at a low critical temperature.

The hyperthermal and magnetic properties of a stable magnetic suspension of magnetite nanoparticles have been studied. To this end, we have developed a low-frequency generator, 300 W, 300 kHz for hyperthermia application. A sample of magnetic suspension was placed in an induction coil and heated to 55°C for 30 minutes. Based on the results of measurements of the transverse susceptibility using radio-frequency resonant magnetometery, it can be concluded that the suspension was superparamagnetic at room temperature and transferred to the magnetic state at nitrogen temperature. Comparing the obtained experimental results with the literature data, we estimated the average size of nanoparticles, which was about 10 nm. Evaluation by computer simulation using the Tikhonov regularization method based on the magnetization curve gives similar results.

The objective of this chapter is to calculate the (stationary) energy confinement time in Tokamak-plasmas with particular emphasis to the assessment of the International Thermonuclear Experimental Reactor (ITER) dynamic energy confinement time scaling. The first part of the chapter is devoted to an estimation of the energy confinement time. The nonlinear thermal balance equation for classical plasma in a toroidal geometry is analytically and numerically investigated including Ion Cyclotron Resonance Heating (ICRH) power. The determination of the equilibrium temperature and the analysis of the stability of the solution are performed by solving the energy balance equation that includes the transport relations obtained by the classical kinetic theory. In the second part of this chapter, we derive the differential equation, which is satisfied by the ITER scaling for the dynamic energy confinement time. We show that this differential equation can also be obtained from the differential equation for the energy confinement time, derived from the energy balance equation, when the plasma is near the steady state. We find that the values of the scaling parameters are linked to the second derivative of the power loss, estimated at the steady state. As an example of an application, the solution of the differential equation for the energy confinement time is compared with the profile obtained by solving numerically the balance equations (closed by a transport model) for a concrete Tokamak-plasma.