Advances and Trends in Physical Science Research Vol. 1

Calculation of Plasmas with Relativistic Collisional Radiative Average Atom Code ATMED CR

A. J. Benita — 2019-05-30

The paper illustrates the computational capability of the collisional-radiative model ATMED CR for calculating the temporal evolution of accurate atomic populations including nlj-splitting, mean charge and atomic processes rates. The present work contains computed time-dependent plasmas with the average atom code ATMED CR of neon and aluminium created with X-ray Free Electron Lasers proposed in the 10th Non-LTE Code Comparison Workshop. The results for plasma properties can be considered as very precise, according to the electronic temperature profiles registered in experiments of laser-created plasmas with duration times of picoseconds and femtoseconds. As a consequence, the Crank-Nicholson implicit numerical iterative temporal module of ATMED CR can be considered a new rapid method for simulating this type of plasmas, avoiding some of the typical difficulties that appear in interpreting results of free electron laser experiments, as very different temporal scales in NLTE regime, enormous matrices of detailed collisional radiative codes, etc. In this paper, it is also presented a representative sample of steady state iron plasmas focusing the attention on two issues. First, the huge computation capability extension up to millions of plasmas with the implementation of a collisional radiative balance in the relativistic average atom model ATMED. Second, it will be addressed the good agreement of atomic and radiative properties not only with respect to very recent experimental measurements of laboratories and High Energy Density facilities, but also to the last theoretical developments in quantum mechanics of statistical methods, as new codes based on the self consistent Hartree-Fock-Slater model for the average atom which in turn solve the Schrödinger’s or Dirac’s equations of radial wave functions. The new codes have been validated with some state of the art models as OPAL, SCO-RCG, STA, CASSANDRA, LEDCOP, THERMOS, etc. The results for plasma properties can be considered as relatively precise and optimal, being checked fundamentally the high sensitivity of calculations to changes in regime, local thermodynamic equilibrium (LTE) or non-LTE (NLTE), electronic and radiation temperatures, dilution factor, matter or electronic density and plasma length. The systematic theoretical investigation is carried out through comparison of calculations performed with a wide set of atomic collisional radiative codes with detailed configurations or codes of the average atom formalism. Some transmissions computed with ATMED CR using UTA (Unresolved Transition Array) formalism are also checked with respect to very recent experimental measurements of laboratories.

Far-infrared Spectra of the Chalcogenide Alloy of the GST System of Composition Ge 15 Sb 15 Te in the Glassy and Crystalline State

V. A. Ryzhov — 2019-05-30

Far-infrared spectra of the chalcogenide alloy of the GST system of composition Ge in the glassy and crystalline states have been measured and analysed in the frequency range of 20–400 cm-1 at room temperature. The absorption in this range is due to the phonon modes of the structural units of crystalline and correlated librational vibrations (boson peak) of glassy alloy, which precede the appearance of relaxation dynamics. IR spectroscopy is one of the most frequently used spectroscopic tools for the crystals and amorphous materials (including chalcogenide) study The vibrational assignments of various absorption bands and the differences revealed in the spectra will make it possible to more confidently elucidate the possible molecular mechanism of the crystal-to-amorphous transition in other chalcogenide alloys. New details of the crystal-to-amorphous transition scenario are suggested. The results, by the example of the composition Ge 15 Sb 15 Te , demonstrate, that the use of far-IR spectroscopy has a clear potential to characterise the local atomic structure and dynamics of the GST alloys. Here experimental evidence is present that along with the change in bonding mechanism there is change medium-range ordering upon crystallisation in GST alloys. Further studies on the new GST materials will give the possibility to improve the parameters of the already developed memory elements and will provide additional information about the nature of the switching effect.

Synthesis of Silver Nanoparticles in Bean (Phaseolus vulgaris L.)

J. Parra Berumen — 2019-05-30

The present work shows a brief review of some natural sources used to produce metallic nanoparticles and leaves the issue open for further discussion and new investigations. The use of nanoparticles has gained an increased attention due to its potential application as a drug delivery medium. The nanoparticle drug delivery characteristics can be engineered to obtain a certain rate or localization, increase the drug load per particle, among others. Some plants have biomolcules for specific functions as reduction and stabilization of the particles formed inside. These biomolecules are for example polyphenolic compounds, hydroxyflavons, oxalic acid, terpenoids and many more. Even the exact nature of the bioreduction of metal ions is not completely understood, the production and investigation of metallic nanoparticles formed in plants have been increased on last 10 years. A wide variety of sizes, 5-150 nm, and shapes, spherical, triangular, rods, hexagonal, have been obtained in plants and fruit extracts. The plant Phaseolus vulgaris (beans) was used to form silver nanoparticles through bioreduction of Ag (I) to Ag (0) in the living plant. Two groups of plants were used. One group of plants grew at garden soil and the other in cotton. To determine the nanoparticles formed in plants, they have been analyzed by using X-ray absorption spectroscopy (XAS). In both cases, a solution of AgNO₃ was added initially in a concentration of 0.01M then the concentration was changed to 0.1 mM.). In stem and leaves silver were found as Ag (0). The XAS spectra were adjusted for more accurate results. Plants may reduce the valence of silver and form nanoparticles. The TEM images show that the average particle size is 18 nm, showing in various forms and a greater number of them in the leaves of plants grown in soil. Results also indicate that nanoparticles obtained from the stem and leaves have different forms and they can affect the soil pH.

Determination of Entropy as a Sum of Heat Capacities

Igor A. Stepanov — 2019-05-30

The physical meaning of phenomenological, thermodynamic entropy is reasoned and elaborated by generalizing Clausius definition with inclusion of generated heat, since it is irrelevant if entropy is changed due to reversible heat transfer or irreversible heat generation. Irreversible, caloric heat transfer is introduced as complementing reversible heat transfer. It is also reasoned and thus proven why entropy cannot be destroyed but is always generated (and thus over-all increased) locally and globally, at every space and time scales, without any exception. An attempt is made to explain the meaning of entropy in thermodynamics. A new concept of heat capacity is defined. For it, the temperature change is measured from 0 kelvin. It is supposed that the entropy of a substance is the sum of these heat capacities in the formation of the substance from 0 kelvin to the actual temperature. This conclusion agrees with experimental data. Entropy is an integral measure of (random) thermal energy redistribution (due to heat transfer and/or irreversible heat generation) within a material system structure in space, per absolute temperature level.

The Four Aspects of Matter and Radiation

Luis Dias Ferreira — 2019-05-30

Are an electron and a positron the same thing? In the essence, they are. As are a co-electron and a co-positron. In fact, these are all four manifestations of a single entity, their matrix-particle. The idea is advocated here that there are four possible ‘aspects’ for massive or massless particles to manifest in whatever reference frame; and this is because Special Relativity admits four variations to standard Lorentz transformations: two basic variations, bradyonic and pseudotachyonic, applying to respectively subluminal and superluminal reference frames; and two others, derived from these ones by simply reversing time. Pseudotachyonic Relativity (PtR), proposed some years ago, show that even though it is impossible to directly detect tahcyons (particles moving faster-than-light), one can detect their co-particles, their ‘images’ moving slower-than-light but with opposite energy, mass and charge. In the process, negative energies naturally arise in Special Relativity, which is quite relevant in ﬁeld theory. One also concludes that time ﬂows in two opposite senses in the Universe and this is why classic theories are essentially time-reversible. The news here come from the discussion of Dirac equation for the electron and how negative energy turns into positive. One discovers that this equation applies as well to negative mass and ﬁnally that its positive and negative solutions are related by ‘antibradyonic’ Lorentz transformations; i.e., concerning Relativity, this explains why each particle has an antiparticle: they are the same. More, Dirac equation agrees with the proposed Quadrivalent Special Relativity in the conclusion that each particle, in a wide sense, may appear (or manifest itself) in one of four aspects, four versions of a single root – the matrix-particle –, depending on its mass-energy signature: 1) ‘straight’ particle; 2) antiparticle (with negative-energy); 3) PtR co-particle (also with negative-energy); 4) and co-antiparticle. This conclusion also applies to massless particles, such as photons, with an equivalent alignment-energy signature.

Negative Adiabatic Lapse Rate of Water: Result of Negative Compressibility

Igor A. Stepanov — 2019-05-30

When the pressure of fluid changes without heat addition, the temperature of the fluid changes; the rate at which the temperature changes with pressure is called the adiabatic lapse rate. According to thermodynamic equations, the adiabatic lapse rate is positive if the thermal expansion coefficient is positive and negative if this coefficient is negative. The adiabatic lapse rate of water is the rate at which its temperature changes with pressure at constant entropy S, and salinity. Experiments show, however, that the adiabatic lapse rate is also positive for substances with negative thermal expansion, although for water it is negative when it has negative thermal expansion. The present paper develops a theory showing that the adiabatic lapse rate must always be positive, but is negative for water because it has negative compressibility in that temperature-pressure region. Numerous substances with negative compressibility have already been identified. The result shows that the traditional thermodynamic equations cannot be used to describe the adiabatic compression of substances because they are derived from the equation which describes heat exchange. The traditional equations predict that substances with negative thermal expansion absorb heat under compression, while numerous experiments show that they express heat. Result also shows that water absorbs heat when it has negative thermal expansion. As many substances with negative compressibility have recently been found, this explanation appears to be plausible. Therefore, the study suggests precise experiments in this low-pressure region. Taking the salinity of water into account does not change the results of the theory.

Analysis of the Nature of Photon Based on Particle-Wave Structure, Size, Unification of Duality

Sen Nian Chen — 2019-05-30

Photon has many basic properties, such as , spin ,…, wave particle duality and so on. But, what structure, what mechanism can make the photon having such basic properties? This work is a proof of that the quantisation of electromagnetic energy is actually the result of Maxwell theory itself.

The object of the study is a slim ordinary symmetrical electromagnetic wave beam. The study does not presuppose it having any relation with the photon and quantisation. The study aims to find out the properties of the symmetrical wave beam. Based on the experimental evidences, well known theories and theoretical reasoning, the study has proved that the beam is composed of an (energy) -packet and a closely connected (electromagnetic) -wave. -packet is a slim circular polarized light wave wrapped by a cylindrical side membrane. Helical structure of E,H plus speed c do make the -packet itself to have a lot of basic properties that are almost as same as the photon’s like , spin ..., include photon size. Combination of -packet and -wave makes the train having both particle property and wave property at the same time, not “exhibit different characters for different phenomenon”. They play role together in the processes of radiation, absorption and diffraction [1,2]. Such combination can be reasonably treated as a photon and vise versa.

On the basis of Maxwell theory and the principle of charges quantisation, the study proved that for any specific frequency, a slim symmetrical electromagnetic wave beam of minimum energy is composted of (energy) -packet and (electromagnetic) -wave. -packet is a wave train of length L and covered by a side membrane of special material. The train possesses basic characters as the photon: , spin , duality, … and satisfies the Maxwell (Schrodinger) equation.

Analysis of the pair production shows that the symmetry will make the charged elementary particles produced possess the spiral structure of mass. It give the possibility to find out the spin mechanism and other important properties of the charged elementary particles [1,2].

The study proves the existence of photon trains in the stimulated emission.

Exact Calculation of the Internal Energy for Ideal Gas in Statistical Mechanics

Igor A. Stepanov — 2019-05-30

Previously, in the calculation of the internal energy of the ideal gas in statistical mechanics, it has been supposed that the volume is a constant, which does not depend on any arguments. However, the volume depends on pressure and temperature, and its partial derivative is not equal to zero. In this paper, the dependence of the volume on pressure and temperature is taken into account, and the internal energy is calculated exactly. It differs from the traditional internal energy by the product of the pressure and volume. This explains three paradoxes in thermodynamics. It follows that the isochoric heat capacity equals the isobaric one. It is shown that the derivation of Mayer’s relation which connects the isochoric and isobaric heat capacities is wrong. This paradox is valid also for real gases because, in a wide range of temperatures and pressures, they only minimally deflect from the ideal gas. It is interesting to note that the obtained result explains the enthalpy paradox. Thermodynamic potentials internal energy, U, and enthalpy, U + PV, are qualitatively different, but, for the ideal gas, they are identical thermodynamically and differ only in the multiplying factor in that U equals 1.5PV, and H equals 2.5PV. If everything were correct in traditional thermodynamics, then U would not be thermodynamically identical to H even for the ideal gas.

Failure of the Identity Linking Thermal Expansion and Isothermal Compressibility in Condensed Phases

Igor A. Stepanov — 2019-05-30

In thermodynamics, there is a relation that connects the thermal expansion coefficient and the isothermal compressibility. It has been supposed that it was a universal identity. However, it is shown here that this identity is not appropriate for condensed phases. Experimental measurements confirm this conclusion. This relation is used in the derivation of Mayer's relation and the heat capacity ratio and proceeds to produce results that significantly deviate from experimental results for condensed phases. An additional mistake is also detected in the derivation of Mayer's relation.