The Concentration Distance and the Average Kinetic Energy of a Diffusible Solute in its Medium

Seven sets of diffusible samples were allowed to diffuse in their medium in order to observe how much meters of distance a given volume of sample will cover in its medium at particular condition. At the same time also to observe how much joules of average kinetic energy that given sample volume possess during the course of its traveling. After successful diffusion by using suitable apparatus, all data associated with this study was carefully observed repeatedly and recorded. In which, mean values were used. Series of findings were found including new equation Xc= which can be used in determining this new initiative (concentration distance of a diffusible solute in its medium (Xc)).

A Pedagogical Approach to Obtain the Combined First and Second Law of Thermodynamics from Classical Statistical Mechanics

The combined first and second law of thermodynamics for a closed system is written as dE=TdS - PdV, where E is the internal energy, S is the entropy, V is the volume, T is the temperature, and P is the pressure of the system. This equation forms the basis for understanding physical phenomena ranging from heat engines to chemical reactors to biological systems. In this work, we present a pedagogical approach to obtain the combined first and second law of thermodynamics beginning with the principles of classical statistical mechanics, thereby establishing a fundamental link between energy conservation, heat, work, and entropy. We start with Boltzmann's entropy formula and use differential calculus to establish this link. Some new aspects of this work include the use of the microcanonical ensemble, which is typically considered to be intractable, to write the partition function for a general system of matter; deriving the average of the inverse kinetic energy, which appears in the microcanonical formulation of the combined first and second law, and showing that it is equal to the inverse of the average kinetic energy; obtaining an expression for the pressure of a system involving many-body interactions; and introducing the system pressure in the combined first and second law via Clausius's virial theorem. Overall, this work informs the derivation of fundamental thermodynamic relations from an understanding of classical statistical mechanics. The material presented herein could be incorporated into senior undergraduate/graduate-level courses in statistical thermodynamics and/or molecular simulations.

Coarse Particle Motion Characteristics in a Double-Stage Slurry Pump Considering Leakage Flow

Along with the pressing demand for the long-distance transportation of coarse particles in the deep-sea mining industry, evaluating the slurry pump’s passing through and erosive wear by studying the particle motion characteristics and the slurry behavior is becoming increasingly important. Research on the influence of leakage flow through the clearance and balancing devices on the motion characteristic of granular grain flow is of great significance but has been seldom studied. This study coupled the discrete element method with the CFD method to investigate the comprehensive effect of a double-stage slurry pump’s main flow and leakage flow on the motion characteristics of particles with a 10 mm diameter. Results show that the leakage flow occupation in main flow falls from 26%–27% to 8%–9% for the two stages, with the flow rate increasing from 80 m3/h to 200 m3/h. In the first stage with leakage, accumulation of coarse particles was observed at the impeller eye, which should be paid much attention to slurry pumps’ operation to eliminate the chance of blockage. In the nonleak situation, although the increment of the average kinetic energy of particles through the impeller is more significant than in the leak case, most of them dissipate primarily by more than 10% collision in the bowl diffuser. In the leak or nonleak case, the average kinetic energy of particles was more than twice through the first stage but only 1.1 times through the second stage. The selection of stages in the slurry pump design should consider the limitation of particle velocity improvement.

Using three elementary particles to construct the physical world

In this paper, we conjecture that gravitation, electromagnetism, and strong nuclear interactions are all produced by particle collisions by determining the essential concept of force in physics (that is, the magnitude of change in momentum per unit time for a group of particles traveling in one direction), and further speculate the existence of a new particle, Yizi. The average kinetic energy of Yizi is considered to be equal to Planck’s constant, so the mass of Yizi is calculated to be <mml:math display="inline"> <mml:mrow> <mml:mn>7.37</mml:mn> <mml:mo>×</mml:mo> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>51</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> kg and the average velocity of Yizi is <mml:math display="inline"> <mml:mrow> <mml:mn>4.24</mml:mn> <mml:mo>×</mml:mo> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mn>8</mml:mn> </mml:msup> </mml:mrow> </mml:math> m/s. The universe is filled with Yizi gas, the number density of Yizi can reach <mml:math display="inline"> <mml:mrow> <mml:mn>1.61</mml:mn> <mml:mo>×</mml:mo> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mrow> <mml:mn>64</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> /m3, and Yizi has no charge. After abandoning the idealism of physics, I try to construct a physical framework from three elementary particles: Protons, electrons, and Yizis. (The elementary particles mentioned here generally refer to the indivisible particles that constitute objects.) The effects of Yizi on the conversion of light, electricity, magnetism, mass, and energy as well as the strong nuclear and electromagnetic forces are emphasized. The gravitation of electromagnetic waves is measured using a Cavendish torsion balance. It is shown experimentally that electromagnetic waves not only produce pressure (repulsion) but also gravitational forces upon objects. The universe is a combination of three fundamental particles. Motion is eternal and follows the laws of conservation of energy and momentum. There is only one force: The magnitude of change in momentum per unit time for a group of particles traveling in one direction. Furthermore, this corresponds to the magnitude of the force that the group of particles exerts in that direction. From this perspective, all physical phenomena are relatively easy to explain.

INVESTIGATION OF THE 16O(γ, p)3H3α REACTION AT THE ENERGIES BELOW THE MESON PRODUCTION THRESHOLD

The reaction 16O(γ, p)3H3 induced by bremsstrahlung photons of endpoint energy Emaxγ = 150 MeV has been studied by the method of a diffusion chamber in a magnetic field. The energy dependence of the total cross section has been measured in the energy range from the threshold and has been founded a broad resonance centered at 55 MeV. The rate of decrease in the cross section undergoes a change in the region around 55 MeV. A comparison was made with the cross section for reactions 4He(γ, p)3H and 12С(γ, р)3H2. The agreement between the shapes of distributions for the (γ, p)3H reactions is evident and was concluded that the mechanism of interaction of the γ-quantum with the nucleus is similar. The dependence of average kinetic energy of particles on the total kinetic energy was determined. In the whole energy interval, the distribution for a proton is more than the statistical distribution. Distribution of relative energy of the proton and 3H nucleus in their c.m.s. does not agree with the predictions of the mechanism of photon absorption by an α-particle cluster, but at energies above the maximum, it agrees with calculations within the framework of the quasi-deuteron model of photoabsorption.

Direct Laser-Driven Electron Acceleration and Energy Gain in Helical Beams

A detailed study of direct laser-driven electron acceleration in paraxial Laguerre–Gaussian modes corresponding to helical beams LG 0 m with azimuthal modes m = 1,2,3,4,5 is presented. Due to the difference between the ponderomotive force of the fundamental Gaussian beam LG 00 and helical beams LG 0 m , we found that the optimal beam waist leading to the most energetic electrons at full width at half maximum is more than twice smaller for the latter and corresponds to a few wavelengths Δ w 0 = 6,11,19 λ 0 for laser powers of P 0 = 0.1 , 1,10 PW. We also found that, for azimuthal modes m ≥ 3 , the optimal waist should be smaller than Δ w 0 < 19 λ 0 . Using these optimal values, we have observed that the average kinetic energy gain of electrons is about an order of magnitude larger in helical beams compared to the fundamental Gaussian beam. This average energy gain increases with the azimuthal index m leading to collimated electrons of a few 100 MeV energy in the direction of the laser propagation.

Multiple Solutions of the Tristable Energy Harvester

This paper presents the results of numerical simulations of a non-linear, tristable system for harvesting energy from vibrating mechanical devices. Detailed model tests were carried out in relation to the system consisting of a beam and three permanent magnets. Based on the derived mathematical model and assuming a range of control parameter variability, a three-dimensional image of the distribution of the largest Lyapunov exponent was plotted. On its basis, the regions of chaotic and predictable movement of the considered system exist have been established. With reference to selected plane of the largest Lyapunov exponent cross-sections, possible co-existing solutions were identified. To identify multiple solutions, a diagram of solutions (DS) diagram was used to illustrate the number of existing solutions and their periodicity. The proposed calculation tool is based on the so-called fixed points of Poincaré cross-section. In relation to selected values of the control parameter w, coexisting periodic solutions were identified for which phase trajectories and basins of attraction were presented. Based on the model tests carried out, it was found that in order to efficiently harvest energy, appropriate transducer adjustment is required. Calibration of the transducer is necessary to obtain the greatest amplitude of vibration of the beam, which corresponds to the phase trajectory limited by external energy potential barriers. As expected, the average voltage induced on the electrodes of the piezoelectric transducer and the average electrical power recorded on the resistive element are directly proportional to the amplitude and average kinetic energy of the beam.

Modelling of Nonlinear Thermodiffusion for a Spherically Symmetric Case

The paper discusses the properties of the nonlinear thermodiffusion equation corresponding to the heat transfer processes occurring with a finite velocity in gas from a high intensity source. In the previous papers A. J. Janavičius proposed the nonlinear diffusion equation which provided a more exact description of impurities diffusion by fast moving vacancies generated by X-rays in Si crystals. This is similar to the heat transfer in gas with constant pressure by molecules carrying a greater average kinetic energy based on the nonlinear thermodiffusion of gas molecules from hot regions to the coldest ones with a finite velocity by random Brownian motions. Heat transfer in gas must be compatible with the Maxwell distribution function. Heat transfer in gas described by using nonlinear thermodiffusion equation with heat transfer coefficients directly proportional to temperature . The solution of the thermodiffusion equation in gas was obtained by using similarity variables. The equation is solved by separating the linear part of the equation that coincides with Fick's second law. The obtained results coincide with Ya.B. Zeldovich’s previously published solutions of nonlinear equations by changing the respective coefficients.

Modern studies of water dynamics in the north-western part of Black sea from LADCP measurements

In this work a result of preliminary analysis of current measurements collected in fourteen large-scale expeditions of the Marine Hydrophysical Institute in 2016–2019 in the north-eastern part of the Black Sea is presented. It is shown that the use of the Lowered Acoustic Doppler Current Profiler (LADCP) significantly increases the information content of the expedition materials, opening up new opportunities in the experimental study of water dynamics. Based on the materials of the expeditions, it was found that the upper layer of shear baroclinic currents in the measurement area is limited by the isopycnic depth with a potential density of ~16.75 kg/m3 (~350 m). At this depth, the variability of the buoyancy frequency with the depth changes from a power-law to an exponential dependence. The same depth limits the penetration of seasonal variations of the average kinetic energy into the water column. The highest values of the average kinetic energy are observed in April-May and November–December, the lowest—in June–August. The ratio of the maximum energy values (summer) to its minimum values (spring, late autumn, winter) was ~3. The Rim Black Sea Current is most pronounced near the Crimean Peninsula in the spring and winter seasons. In summer and autumn, the horizontal distribution of the current velocity in depths of 30–80 m is less structured, which is caused by the seasonal intensification of mesoscale processes. At a number of stations, the current velocity profiles contain fragments with a well-defined harmonic variability of the current velocity components with depth, which can be interpreted as the manifestation of near-inertial internal waves. In most cases, the rotation of the current velocity vector with depth occurs clockwise, which determines the main direction of propagation of the inertial internal waves into the water column. The example of one of the stations shows the significant contribution of such waves to the value of shear. This fact suggests a significant influence of near-inertial internal waves on the processes of vertical turbulent exchange in the water column.

Study of Colliding Particle-Pair Velocity Correlation in Homogeneous Isotropic Turbulence

This paper deals with the numerical analysis of the particle inertia and volume fraction effects on colliding particle-pair velocity correlation immersed in an unsteady isotropic homogeneous turbulent flow. Such correlation function is required to build reliable statistical models for inter-particle collisions, in the frame of the Euler–Lagrange approach, to be used in a broad range of two-phase flow applications. Computations of the turbulent flow have been carried out by means of Direct Numerical Simulation (DNS) by the Lattice Boltzmann Method (LBM). Moreover, the dependence of statistical properties of collisions on particle inertia and volumetric fraction is evaluated and quantified. It has been found that collision locations of particles of intermediate inertia, StK~1, occurs in regions where the fluid strain rate and dissipation are higher than the corresponding averaged values at particle positions. Connected with this fact, the average kinetic energy of colliding particles of intermediate inertia (i.e., Stokes number around 1) is lower than the value averaged over all particles. From the study of the particle-pair velocity correlation, it has been demonstrated that the colliding particle-pair velocity correlation function cannot be approximated by the Eulerian particle-pair correlation, obtained by theoretical approaches, as particle separation tends to zero, a fact related with the larger values of the relative radial velocity between colliding particles.