Band 17, Heft 1

This article offers a detailed analysis of the Ising model in 2D small-world networks with competing Glauber and Kawasaki dynamics. The non-equilibrium stationary state phase transitions are obtained in these networks. The phase transitions are discussed, and the phase diagrams are obtained via Monte Carlo simulations and finite-size analyzing. We find that as the addition of links increases the phase transition temperature increases and the transition competing probability of tricritical point decreases. For the competition of the two dynamics, ferromagnetic to anti-ferromagnetic phase transitions and the critical endpoints are found in the small-world networks.

The current work analyzes the transmission behavior of plane harmonic waves in an isotropic medium. The observation is made for homogeneous type solid in the context of generalized dual phase lag model of thermoelasticity. Concept micro-temperature, where the microelements have different temperatures has also been considered. The basic focus of thework is to predict the influence of initially applied magnetic field on plane waves through the elastic solid. We have made an attempt to find exact solution of the problem using an analytical technique of a normal mode analysis method. The theoretical results are obtained for a generalized solid in order to test the numerical calculation of a magnesium crystal. It is found that the magnetic field reduces the strength of the attenuation factor.

Topological indices are the numerical values associated with chemical structures that correlate physico-chemical properties with structural properties. There are various classes of topological indices such as degree based topological indices, distance based topological indices and counting related topological indices. Among these classes, degree based topological indices are of great importance and play a vital role in chemical graph theory, particularly in chemistry. In this report, we have computed the multiplicative degree based topological indices of honeycomb derived networks of dimensions I, 2, 3 and 4.

Dendrimers are profoundly extended natural macromolecules with successive layers of branch units encompassing a central core. Topological indicess are numbers related with graph of a compound to allow quantitative structureactivity/property/lethality connections. These topological indices relate certain physico-chemical properties like stability, boiling point, strain energy and so forth of a compound. In this report, there have been computed redefined first, second and third Zagreb indices of Nanostar dendrimers. The authors also analyzed some Zagreb polynomials of understudy dendrimers.

Solar energy is one of the most promising types of renewable energy. Flat facet solar concentrators were proposed to decrease the cost of materials needed for production. They used small flat mirrors for approximation of parabolic dish surface. The first prototype of flat facet solar concentrators was made in Australia in 1982. Later various prototypes of flat facet solar concentrators were proposed. It was shown that the cost of materials for these prototypes is much lower than the material cost of conventional parabolic dish solar concentrators. To obtain the overall low cost of flat facet concentrators it is necessary to develop fully automated technology of manufacturing and assembling processes. Unfortunately, the design of known flat facet concentrators is too complex for automation process. At present we develop the automatic manufacturing and assembling system for flat facet solar concentrators. For this purpose, we propose the design of flat facet solar concentrator that is convenient for automatization. We describe this design in the paper. At present, almost all solar-energy plants in the world occupy specific areas that are not used for agricultural production. This leads to a competition between the solar-energy plants and agriculture production systems. To avoid this competition, it is possible to co-locate solar-energy devices in agricultural fields. The energy obtained via such co-location can be used for agricultural needs ( e.g ., water extraction for irrigation) and other purposes ( e.g ., sent to an electrical grid). In this study, we also describe the results of an investigation on co-location methods for the minimal loss of agricultural harvest too.

The idea of multi cohesive areas is a new, theoretical model of quantum particle mass. This model contains a dark matter sector. Moreover, it can explain the current experimental data on both dark matter and dark energy phenomena. In this work, the current status of this idea from theoretical and experimental perspective will be shown. It will be done by presenting the motivation behind its creation, its theoretical foundation and how it explains the mentioned current experimental data. The result from this work is a proof that in the further MCA development, quantities like particles or fields have to find a new image in which they are created by the speed of light. The conclusion from this work is that the mentioned development can create a theory for all interactions. Moreover, such a theory will have a practical value. Namely, by using this theory, the “disappearing” matter in the visible world will be available by changing into dark matter. This, together with the fact that the current dark matter models do not yield any significance outcomes, is a proof that such a development is at least worth considering.

The article presents innovative method of deriving dynamics in the Special Theory of Relativity. This method enables to derive infinitely many dynamics in relativistic mechanics. The authors have shown five examples of these derivations. In this way,It is presented that the dynamics known today as the dynamics of Special Theory of Relativity is only one of infinitely of theoretically possible.

This article deals with the nonlinear head-on collision between two hydroelastic solitary waves in plate–covered water with Nwogou’s Boussinesq model for the nonlinear fluid motion. This model contains a parameter α that is associated with horizontal velocities according to the chosen level of horizontal velocity variables. A thin elastic cover is considered as the Euler–Bernoulli beam model. To derive the series solution, we apply the Poincaré–Lighthill–Kuo (PLK) method to solve analytically the highly nonlinear coupled partial differential equations. The impact of all the physical parameters is discussed with the help of the asymptotic solutions and graphic representations. In particular, the authors address the behavior of plate deflection, maximum run-up during a collision, phase shift, distortion profile, and wave speed. It is found that the variation of the free parameter α and plate terms dramatically change the amplitude of a solitary wave. It is noticed that a very small tilting occurs due to the distortion in wave profile. The maximum run-up amplitude and the wave speed rise due to a greater influence of the free parameter. The phase shift tends to diminish due to an increment in the free parameter and plate terms. The novelty of the present methodology is compared with previously published results.

The experiment design may need a stress level higher than use condition which is called accelerate life tests (ALTs). One of the most ALTs appears in different applications in the life testes experiment is partially step stress ALTs. Also, the experiment items is failure with several fatal risk factors, the only one is caused to failure which called competing risk model. In this paper, the partially step-stress ALTs based on Type-II censoring scheme is adopted under the different risk factors belong to Chen lifetime distributions. Under this assumption, we will estimate the model parameters of the different causes with the maximum likelihood method. The two, asymptotic distributions and the parametric bootstrap will be used to build each confidence interval of the model parameters. The precision results will be assessed through Monte Carlo simulation study.

The parametric interaction of optical wave pulses in metamaterials is considered in the first approximation of the theory of dispersion. The interaction between the quasi-monochromatic pump wave and the wave pulse at the total frequency with quadratic phase modulation is assumed. The results of calculation of the shape of the spectrum of an excited signal wave at a difference frequency are presented for low frequency pumping. It is shown that the effects of group mismatch in metamaterials lead to a narrowing of the spectrum of the excited wave. With an increase in the modulation degree of a weak exciting wave, the spectrum of the excited wave broadens.

The conventional equations for describing the flow characteristics of the mixtures merely consider fluid that is homogenic, if it is above the bubble point conditions but ignore that a system containing sub-micron sized gas or vapor bubbles distributed throughout the volume of the liquid, which can exhibit unexpected heterogenic and complex phase properties. In this paper, a new mathematical model for the flowing gas-liquid mixture is presented, which has been proposed considering the colloidal feature of the system above the saturation or bubble point pressure. This approach is more in line with the actual dynamic performance of the oil and gas mixture export pipeline. Experimental data, simulations and field case studies validate the new proposed mathematical model of flow characteristics in pipeline. The obtained results confirmed that the calculated data are in good agreement with the experimental data. Based on Azerbaijan oil-gas-condensate field “Guneshli” data, this new model was used for calculating the condition in which the transformation of the flow characteristics from stable into instable is occurred. It has been discovered that the flow becomes unstable at a pressure about 30% higher than Bubble Point Pressure, which causes pulsation effect in the pipeline structure. However, homogenic behavior should be observed in this hydrodynamic condition. Also, the model provides a guideline on how to optimize the flow rate by adjusting the pipeline parameters to minimize the flow resistance, liquid slugging and hydraulic hammering effects, which cause instable operation.

During the past few decades, the technologies of the higher-shot densities, larger perforating guns and tubing-conveyed perforation (TCP) combined well testing have been used widely used for well completions. This results in a large increase of impact loads in the tubing during TCP. The safety of the tubing is directly related to the success of perforation combined well test,which is the key link in the oil and gas production. In this study, the influence factors of perforating impact load have firstly been analyzed. Also the dynamic response of tubing during TCP in three dimensions has been studied by numerical simulation. According to the computing results, the vulnerable parts of tubing during TCP have been found, where the axial impact load is the strongest and it is concluded that the axial shock absorber has the optimal installation position to achieve the best shock absorption effect, which is verified by the case. This study proposes a novel method for the safety analysis of the tubing, which has important significance to provide guidance for the design of field perforating operations and to improve security.

This work presents a mathematical model, a computational scheme and experimental results describing the electrodynamic characteristics of a nonmagnetic, isotropic, E-polarized, nonlinear layered dielectric object with a cubically polarizable medium. The nonlinear object is irradiated by a quasi-homogeneous field, where the incident field constitutes of a packet of phase-synchronized plane oscillations. In the case under consideration the excitation may consist both of a highly intense electromagnetic field at a basic (fundamental) frequency, which results in the generation of the third harmonic, as well as of weakly intense fields at multiples of the basic frequency which produce no harmonics, but only have an influencing effect on the processes of wave radiation. The investigations were carried out within the setting of a coupled system approach at resonant excitation frequencies determined by the eigenvalues of the induced eigenvalue problems. A verification of the energy balance law is carried out. By means of estimations for the conditionalities of the occuring matrices, the level of degeneration of the induced non-self-adjoint spectral problems as well as the sensitivity of the coupled system of nonlinear boundary value problems with respect to computational errors are verified.

In hadron therapy, the accelerated ions, interacting with the body of the patient, cause the fragmentation of both projectile and target nuclei. The fragments interact with the human tissues depositing energy both in the entrance channel and in the volume surrounding the tumor. The knowledge of the fragments features is crucial to determine the energy amount deposited in the human body, and - hence - the damage to the organs and to the tissues around the tumor target. The FOOT (FragmentatiOn Of Target) experiment aims at studying the fragmentation induced by the interaction of a proton beam (150-250 MeV/n) inside the human body. The FOOT detector includes an electronic setup for the identification of Z ≥ 3 fragments integrated with an emulsion spectrometer to measure Z ≤ 3 fragments. Charge identification by nuclear emulsions is based on the development of techniques of controlled fading of the particle tracks inside the nuclear emulsion, that extend the dynamical range of the films developed for the tracking of minimum ionising particles. The controlled fading strongly depends on temperature, relative humidity and treatment duration. In this study the performances in terms of charge separation of proton, helium and carbon particles, obtained on a batch of new emulsion films produced in Japan are reported.

The present study describes the fragmentation of the amino acid L-threonine (C 4 H 9 NO 3 ) with and without the inclusion of water influence. The fragmentation of the L-threonine molecule was theoretically studied using the Becke’s three-parameter hybrid functional method by applying the non-local correlation provided by Lee, Yang and Parr (B3LYP) with the correlation consistent triple zeta basis (cc-pVTZ). The polarizable continuum model (PCM) was used to evaluate the influence of water. Fragments were selected based on data from mass spectrometry experiments. The chemical compositions of fragments were identified, and the appearance energy was calculated. Based on the obtained results, we can conclude that water affects the appearance energy, the fragment structure and the fragment formation processes.

The well-known low-pressure monatomic gas thermal conductivity expression is based on the Maxwell-Boltzmann velocity distribution and involves the mean particle velocity, the gas heat capacity at constant volume and the particle mean free path. The extension of the formula to a free electron Fermi gas, using the Fermi velocity along with the Sommerfeld electronic heat capacity, was demonstrated in the literature using the Boltzmann transport equation. A different formulation of heat conduction in sufficiently pure metals, yielding the same formula for the thermal conductivity, is provided in the present investigation using the free electron Fermi gas energy distribution with the thermal conductivity determined from the net heat transfer occurring due to random motions of the free electrons in the presence of temperature gradient. Potential applications of this approach include extension of the present kinetic model incorporating quantum effects to cases in which electron scattering occurs such as in nanowires and hollow nanowires.

Aiming at the problem of systems’ dynamic characteristics’ randomness caused by connection gaps of submerged multi-body structures, a stochastic and uncertainty dynamical model were formulated for connection gaps and dynamic elongation of mooring cables. This model considered sag effect caused by light, soft and low damping characteristics of mooring cables and their dynamic elongation under the impact of flow field and connection gaps. The equivalent elastic modulus method was used to modify the sag effect. The Newmark- β method was used to solve the problem. Calculation results showed that the average value and peak value of floating body displacement caused by uncertainty of gap contact states are larger than those of ideal articulated states. The reliability of floating body’s displacement with gap contact will be reduced to different extents and the reliability of displacement in velocity direction changes greatly, especially perpendicular to flow field. When studying multi-body structures, randomness of contact state should be considered to reduce the dispersion of clearance and improve dynamic performance.

Samples taken from the human brain ( Globus Pallidus ) have been investigated by physical techniques such as light microscopy, scanning electron microscopy, transmission electron microscopy, Mössbauer spectroscopy and SQUID magnetometry. SEM-EDX/TEM investigation reveals multielemental composition of hematite and magnetite nanocrystals with sizes ranging from 40 nm to 100 nm and hematite microcrystals from 3 μm to 7 μm. Room temperature Mössbauer spectra show quadrupole doublets assigning to hematite and ferrihydrite. SQUID measurements of temperature dependence of the mass magnetic susceptibility between T = 2 – 300 K at DC field B 0 = 0.1 T, the field dependence of the mass magnetization taken at the fixed temperature T 0 = 2.0 and 4.6 K and the zero-field cooled and field cooled magnetization experiments (ZFCM/FCM) confirm a presence of ferrimagnetic phases such as maghemite and/or magnetite with hysteresis loops surviving until the room temperature. Differences between these measurements from the point of view of iron oxides detected can indicate important processes in human brain and interactions between ferritin as a physiological source of iron and surrounding environment.

The investigations of integrability, exact solutions and dynamics of nonlinear partial differential equations (PDEs) are vital issues in nonlinear mathematical physics. In this paper, we derive and solve a new Lax integrable nonisospectral integral-differential system. To be specific, we first generalize an eigenvalue problem and its adjoint equation by equipping it with a new time-varying spectral parameter. Based on the generalized eigenvalue problem and the adjoint equation, we then derive a new Lax integrable nonisospectral integral-differential system. Furthermore, we obtain exact solutions and their reduced forms of the derived system by extending the famous non-linear Fourier analysis method–inverse scattering transform (IST). Finally, with graphical assistance we simulate a pair of reduced solutions, the dynamical evolutions of which show that the amplitudes of solutions vary with time.

Resolving partition and partition dimension have multipurpose applications in computer, networking, optimization, mastermind games and modelling of chemical substances. The problem of finding exact values of partition dimension is hard so one can find bound for the partition dimension of a general family of graph. In the present article, we give the sharp upper bounds and lower bounds for the partition dimension of m -wheel, W n , m for all n ≥ 4 and m ≥ 1. Presented data generalise some already available results.

To analyze the focal characteristics of cylindrically polarized beams, a visual analysis method is proposed. As known, the focal field can be described by three mutually perpendicular components, each one is the total contribution of all parts of the incident beams. For each component of all contributing parts weapply path integral method, then from the path integral curves extract focal field properties immediately, such as polarization state or intensity distribution. The analysis process of PI is visual and more understandable, and has more powerful information extraction function, which is also helpful for the design of special filtering pupil.

Recent astrophysical observations hint toward the need for an extended theory of gravity to explain puzzles presented by the standard cosmological model such as the need for dark matter and dark energy to understand the dynamics of the cosmos. This paper investigates the effect of a repulsive central universal force field on the behavior of celestial objects. Negative tidal effect on the solar and galactic orbits, like that experienced by Pioneer spacecrafts, was derived from the central force and was shown to manifest itself as dark matter and dark energy. Vertical oscillation of the sun about the galactic plane was modeled as simple harmonic motion driven by the repulsive force. The proposed universal field was used to infer the shape of dark matter halos as generated from a planar component of the universal force and to explain galactic warp, galactic halo density, and galactic rotation curves. It was found that the repulsive field addition to Newton’s gravity mimics the Yukawa potential correction employed by many current gravitational theories that modify gravity.

The solution of nonlinear mathematical models has much importance and in soliton theory its worth has increased. In the present article, we have investigated the Caudrey-Dodd-Gibbon and Pochhammer-Chree equations, to discuss the physics of these equations and to attain soliton solutions. The exp(− ϕ ( ζ ))-expansion technique is used to construct solitary wave solutions. A wave transformation is applied to convert the problem into the form of an ordinary differential equation. The drawn-out novel type outcomes play an essential role in the transportation of energy. It is noted that in the study, the approach is extremely reliable and it may be extended to further mathematical models signified mostly in nonlinear differential equations.

This review, of the understanding of quantum mechanics, is broad in scope, and aims to reflect enough of the literature to be representative of the current state of the subject. To enhance clarity, the main findings are presented in the form of a coherent synthesis of the reviewed sources. The review highlights core characteristics of quantum mechanics. One is statistical balance in the collective response of an ensemble of identically prepared systems, to differing measurement types. Another is that states are mathematical terms prescribing probability aspects of future events, relating to an ensemble of systems, in various situations. These characteristics then yield helpful insights on entanglement, measurement, and widely-discussed experiments and analyses. The review concludes by considering how these insights are supported, illustrated and developed by some specific approaches to understanding quantum mechanics. The review uses non-mathematical language precisely (terms defined) and rigorously (consistent meanings), and uses only such language. A theory more descriptive of independent reality than is quantum mechanics may yet be possible. One step in the pursuit of such a theory is to reach greater consensus on how to understand quantum mechanics. This review aims to contribute to achieving that greater consensus, and so to that pursuit.

In this paper, the problem of wave propagation in a compressible half-space with an initial stress is considered. General discussion on the speed of wave in the presence of an initial stress is presented. Furthermore, reflection of a homogeneous plane P −wave is also studied. A special strain energy function dependent on this initial stress is used to understand the response of the materials. Explicit formulas for the reflection coefficients are also presented. General nonlinear theory and the theory of invariants are used to derive theoretical results. Graphical illustration of theoretical results for various numerical values of parameters show that initial stress has considerable bearing on the behavior of a plane wave.

This paper presents an evaluation of the realism of a full-color reflection H2 analog hologram recorded on ultra-fine-grain silver-halide material. An H2 hologram is a transplane image that is different from the well-known Denisyuk hologram in which the final image appears fully behind the surface of the glass plate. We explain how to record this type of transplane image on the silver-halide holographic material Ultimate 04. Evaluations are performed using a mixed reality experience questionnaire. The realism of our full-color H2 hologram is successfully demonstrated and shows the potential for its integration into a diorama.

In this paper we introduce the concept of segmentation based on mathematical approach using graph theory algorithms using the family of augmenting paths algorithms. We present a new program, an implementation, algorithms and obtained results devoted to segmentation of biomedical data. We implement our program for handling with segmentation, counting a measure of the existence of the minerals in the biomedical data. As a consequence we prove the existence of minerals in the data obtained from the brain of rabbits.

In the paper, we research a time fractional modified KdV-type equations.We give the symmetry reductions and exact solutions of the equations, and we investigate the convergence of the solutions. In addition, the conservation laws of the equations are constructed.

In this work we investigate the equal-width equation, which is used for simulation of (1-D) wave propagation in non-linear medium with dispersion process. Firstly, Lie symmetries are determined and then used to establish an optimal system of one-dimensional subalgebras. Thereafter with its aid we perform symmetry reductions and compute new invariant solutions, which are snoidal and cnoidal waves. Additionally, the conservation laws for the aforementioned equation are established by invoking multiplier method and Noether’s theorem.

The present paper related to thin film flows of two immiscible third grade fluids past a vertical moving belt with slip conditions in the presence of uniform magnetic field. Immiscible fluids we mean superposed fluids of different densities and viscosities. The basic governing equations of continuity, momentum and energy are incorporated. The modeled coupled equations are solved analytically by using Adomian Decomposition Method (ADM) along with Homotopy Analysis Method (HAM). The residual errors show the authentication of the present work. For comparison, numerical method (ND-Solve) is also applied and good agreement is found. The effects of model parameters on velocity, skin friction and temperature variation have been studied. At the end, the present study is also compared with single layer flow and revealed in close agreement with the result available in the literature.

In this work, we study vibrations of three-layered cylindrical shells with one ring support along its length. Nature of material of the central layer is a functionally graded material (FGM) type. The considered FGM is of stainless steel and nickel. The internal and external layers are presumed to be made of isotropic material i.e., aluminum. The functionally graded material composition of the center layer is assorted by three volume fraction laws (VFL) which are represented by mathematical expressions of polynomial, exponential and trigonometric functions. The implementation of Rayleigh-Ritz method has been done under the Sanders’ shell theory to obtain the shell frequency equation. Natural frequencies (NFs) are attained for the present model problem under six boundary conditions. Use of characteristic beam functions is made for the estimation of the dependence of axial modals. The impact of layer material variations with ring support is considered for many ring positions. Also the effect of volume fraction laws is investigated upon vibration characteristics. This investigation is performed for various physical parameters. Numerous comparisons of values of shell frequencies have been done with available models of such types of results to verify accuracy of the present formulation and demonstrate its numerical efficiency.

The performance and potential of a process of industrial products is assessed under lower specification limit L by lifetime performance index ( C L ). In this paper, under consideration the independent lifetimes Chen products with known one shape parameters the C L of the performance of a process is evaluated. For the hybrid censoring scheme the maximum likelihood (ML) estimate of C L is constructed as well as confidence interval for C L is developing. Also, Bayesian approach is adopted to estimates C L and credibly interval is constructed. Some theoretical results of hypothesis tests of C L is adopted. Finally, our obtaining results will be assessed and compared through Monte Carlo simulation study and numerical example.

In order to detect coal and gas outburst disasters by means of electric exploration technology, the characteristics of gas adsorption/desorption electrical response were studied. The law of resistivity variation of different coal samples was investigated under different gas pressures with the aid of a self-built real-time test system of coal resistivity during gas adsorption/desorption. In addition, the mechanism of coal resistivity variation was studied. The research results indicate that coal resistivity decreases during gas adsorption and increases during gas desorption, but generally it cannot return to the initial value. Gas influences coal resistivity through a variety of mechanisms. In the gas adsorption process, coal resistivity decreases under the combined effect of surface energy decline, skeleton expansion, free gas pressure and adsorption swelling stress. In addition, as the gas pressure rises, the resistivity varies in a wider range. The coal resistivity shares the relation of y = a + b ln( x + c ) with gas pressure and the relation of y = ax + b with the content of adsorbed gas. This study lays a foundation for the application of electrical prospecting technology to gas hazard prediction and provides technical support for safe production in coal mines.

Structural analysis of aeromagnetic and Landsat data over Ankpa area, Benue state was carried out to delineate the basement topography, hydrocarbon potentials, groundwater availability and the structures that control basin formation. The Landsat imagery generated from this study was further processed using Geomatica software (version 9.0). The results obtained revealed that the drainage pattern is dendritic which could be associated to the lithological, structural and topographic differences. Also, this may indicate the presence of alluvial rocks, typically of the same geology, mainly of sedimentary rocks. This present study is in good agreement with the areas in the lineament map of high-density structures. The observation showed that the study area constitutes densely lineaments that cut across each other, which may be attributed to groundwater availability and upward migration of hydrocarbon-bearing formation. The structural trend is predominantly in the NE-SW direction and agrees with the Landsat data structural trends. Significantly, this NE-SW trend is in agreement with the trend of Benue Trough (NE –SW) and could be that they have the same structural control.

In this article we introduce a new six - parameters model called the Beta Generalized Exponentiated-Frechet (BGEF) distribution which exhibits decreasing hazard rate. Many models such as Beta Frechet (BF), Beta ExponentiatedFrechet (BEF), Generalized Exponentiated-Frechet (GEF), ExponentiatedFrechet (EF), Frechet (F) are sub models. Some of its properties including r th moment, reliability and hazard rate are investigated. The method of maximum likelihood isproposed to estimate the model parameters. The observed Fisher’s information matrix is given. Moreover, we give the advantage of the (BGEF) distribution by an application using two real datasets

Swarm intelligence method is an effective way to improve the particle degradation and sample depletion of the traditional particle filter. This paper proposes a particle filer based on the gravitation field algorithm (GF-PF), and the gravitation field algorithm is introduced into the resampling process to improve particle degradation and sample depletion. The gravitation field algorithm simulates the solar nebular disk model, and introduces the virtual central attractive force and virtual rotation repulsion force between particles. The particles are moves rapidly to the high-likelihood region under action of the virtual central attractive force. The virtual rotation repulsion force makes the particles keep a certain distance from each other. These operations improve estimation performance, avoid overlapping of particles and maintain the diversity of particles. The proposed method is applied into INS/gravity gradient aided navigation, by combining the sea experimental data of an inertial navigation system. Compared with the particle swarm optimization particle filter(PSO-PF) and artificial physics optimized particle filter (APO-PF), the GF-PF has higher position estimate accuracy and faster convergence speed with the same experimental conditions.

In this article it is proven that Maxwell’s field equations are invariant for a real orthogonal Cartesian space time coordinate transformation if polarization and magnetization are assumed to be possible in empty space. Furthermore, it is shown that this approach allows wave propagation with finite field energy transport. To consider the presence of polarization and magnetization an alternative Poynting vector has been defined for which the divergence gives the correct change in field energy density.

To solve unstable operating and serious wearing of a hydraulic turbine in its overflow parts under solid-liquid two-phase flow, a particle model software and an inhomogeneous model in CFX are used to simulate the hydraulic turbine to understand the wearing of overflow parts and the external characteristics under the solid-liquid two-phase flow. Eleven different conditions at different densities and concentration have been calculated. The simulation results show that the volume distribution of solid particles is larger at the turn of the volute and nose end, resulting in the serious wear in this area. Due to uniform flow at the butterfly edge of volute under solid-liquid two-phase flow, the wear at the entrance of guide vane, the inlet of the blade and the outlet in the shroud is more serious than in other sections. Meanwhile, the collision between the solid phase particles and the overflow components is more intense under solid-liquid two-phase flow in the rotor which can lead to cavitation especially in the outlet and shroud of the blade. In addition, with the increase of density and concentration of solid particles the inlet and outlet pressure difference gradually rises, causing the efficiency loss of the hydraulic turbine.

A powerful algorithm is proposed to get the solutions of the time fractional Advection-Diffusion equation(TFADE): A B C D 0 + , t β u ( x , t ) = ζ u x x ( x , t ) − κ u x ( x , t ) + $^{ABC}\mathcal{D}_{0^+,t}^{\beta}u(x,t) =\zeta u_{xx}(x,t)- \kappa u_x(x,t)+$ F ( x , t ), 0 < β ≤ 1. The time-fractional derivative A B C D 0 + , t β u ( x , t ) $^{ABC}\mathcal{D}_{0^+,t}^{\beta}u(x,t)$is described in the Atangana-Baleanu Caputo concept. The basis of our approach is transforming the original equation into a new equation by imposing a transformation involving a fictitious coordinate. Then, a geometric scheme namely the group preserving scheme (GPS) is implemented to solve the new equation by taking an initial guess. Moreover, in order to present the power of the presented approach some examples are solved, successfully.

In this paper, with the help of an analytical approach, new complex singular and travelling dark solutionsto the nonlinear electrical transmission line are successfully constructed. 2D and 3Dfigures along with contour figures are plotted. Finally, at the end of manuscript, general conclusions about these novel findings, which differ from existing results, are given.

Recently, a method for calculating the quantum spectrum of black holes has been proposed. We show that this method can be applied for radiations of 4 + n - dimensional water around a DNA. In this model, DNA acts like a black hole and produces a curved space-time in a water around it. In these conditions, molecules of water in four dimensional universe are entangled with some DNA-like structures in extra dimension. Consequently, the effects of structures of water in extra dimensions can be observed in four dimensions. The entangled structures emit some quantum spectrum which can be transmitted to pure waters. These waves produce a curved space-time in pure water and make an entanglement between structure of water on four and DNA-like structures in extra dimensions. As a result, some signatures of DNAs can be observed in pure water. This model helps us to understand the reason for the emergence of life on the earth. To explain the model better, we unify Darwin’s theory with string theory in a new Darwinian’s string theory. In this theory, a zero dimensional manifold decays into two types of closed strings. One type decays into open strings and then these strings join to each other and form cosmos. Another type decays into open strings which form biological matters like DNAs and molecules of water in universe and anti-DNAs and anti-water in anti-universe. Thus, DNAs and molecules water are connected to each other and anti-DNAs and molecules of anti-water in anti-universe through some closed strings. These strings helps to molecules of water to store their informations in extra dimension and have long time memory. Because, information that are transformed into extra dimensions through closed strings, could be returned into universe. Also, these closed strings could have the main role in DNA transduction. Because, they connect two tubes one including water and DNA and another pure water in universe to two tubes including anti-DNA and water in anti-universe and transform properties of DNA into pure water. As a result, Darwinian string theory can confirm both water memory and DNA transduction. Finally, this theory response to this question that why memory of water couldnt remain for a long time. In this model, open strings which connects atoms in universe with anti-atoms in anti-universe interact with open strings which connects molecules of water and anti-water and decrease their entanglement. This causes that exchanging information between water and anti-water decreases and memory is dis-appeared.

Quantum algorithm is an algorithm for solving mathematical problems using quantum systems encoded as information, which is found to outperform classical algorithms in some specific cases. The objective of this study is to develop a quantum algorithm for finding the roots of n th degree polynomials where n is any positive integer. In classical algorithm, the resources required for solving this problem increase drastically when n increases and it would be impossible to practically solve the problem when n is large. It was found that any polynomial can be rearranged into a corresponding companion matrix, whose eigenvalues are roots of the polynomial. This leads to a possibility to perform a quantum algorithm where the number of computational resources increase as a polynomial of n. In this study, we construct a quantum circuit representing the companion matrix and use eigenvalue estimation technique to find roots of polynomial.

The steady state response of a fractional order vibration system subject to harmonic excitation was studied by using the fractional derivative operator − ∞ D t β , ${}_{-\infty} D_t^\beta,$where the order β is a real number satisfying 0 ≤ β ≤ 2. We derived that the fractional derivative contributes to the viscoelasticity if 0 < β < 1, while it contributes to the viscous inertia if 1 < β < 2. Thus the fractional derivative can represent the “spring-pot” element and also the “inerterpot” element proposed in the present article. The viscosity contribution coefficient, elasticity contribution coefficient, inertia contribution coefficient, amplitude-frequency relation, phase-frequency relation, and influence of the order are discussed in detail. The results show that fractional derivatives are applicable for characterizing the viscoelasticity and viscous inertia of materials.

To improve the accuracy of numerical control machine tools error, this paper studies the application of laser testing technology in numerical control machine tool, and put forward a laser interferometer automatic aiming system which can conduct space error measurement. The system, in the process of the NC machine tool operating, can measure the machine tool space curve through changing the direction of the laser. The principle of laser interferometer and matlab analysis are adopted, through the experiment of laser interference technology in the numerical control machine tool, the law curve of error in NC machine tools is obtained, getting the method of error of NC machine tools. When conducting laser testing error experiment in NC machine tool, the results show that the laser testing can measure aggregated error and thermal error of NC machine tool better, with small control of environment and high accuracy of measurement.

As the starting point, the immunity theory is introduced into the organization quality management, combined with the organization quality specific immunity system, the evaluation index system of organization quality specific immunity is designed. And the evaluation and multi-attribute group decision making model of organization quality specific immunity based on the immunity perspective is constructed by the method of multi-attribute group decision making of intuitive pure linguistic aggregation operators, empirical analysis is carried out by the research objects of relevant experts, representative and typical manufacturing enterprises, the empirical analysis results indicate that multi-attribute group decision making method of intuitive pure linguistic aggregation operators can choose and determine the optimization evaluation solution and the best decision making of partners, confirm the highest value over all partners for organization quality specific immunity system, the method of multi-attribute group decision making of intuitive pure linguistic aggregation operators has validity, feasibility and operability in evaluation and decision making of organization quality specific immunity. Empirical analysis results and conclusion have certain practical value, which provide new ideas to solve the problem of multi-attribute decision making of intuitive information mixed with pure linguistic information, and provides the basis for the effective selection of the best partners for manufacturing enterprises of the supply chain from the perspective of quality management.

In key frame extraction of multi-resolution remote sensing image using traditional key frame image feature extraction method, only the feature information of remote sensing images, rather than cluster operation of the remote sensing images is considered, which leads to low efficiency and poor quality of extraction results. To this end, the key frame extraction algorithm of multi-resolution remote sensing image under quality constraint was proposed. Through similarity between image features and the selected image frame, rough key frame can be extracted. On this basis, the key frame extraction of multi resolution remote sensing image based on quality constraints was used to perform clustering operation for multi-resolution remote sensing image corresponding to rough key frame, which shortened the time length for retrieval of key frame image. According to the clustering results, multi-resolution remote sensing images were divided into several clusters. The key frame of each cluster can be obtained by calculating the distance between remote sensing image and cluster center. For key frames that had been determined, their quality was evaluated to meet standard, so as to realize effective extraction of key frame of multi-resolution remote sensing images. The experimental results show that the proposed method can significantly improve the quality of key frame extraction of multi-resolution remote sensing images.

In this paper, the experimental paradigm of cognitive behaviors to study the cognitive activities in the contiguous sense cognition of the tested linen clothing is introduced. The experimental program is written with E-Prime 2.0, while the expression of experimental stimulus material is realized with the developed dressing contiguous sense measurement device, which output the senses of urtication, roughness and smoothness among the fabric contiguous sense. Changing the relative force for the contact between fabric and human skin, the dressing contiguous sense is tested in different contiguous force conditions. The result shows that, with the increase of relative contiguous force, the evaluation value for the sense of urtication is increase, the value for the roughness sense is also increase, but that for the smoothness sense is decrease.

Despite the rapid development of urban rail transit in China, there are still some problems in train operation, such as low efficiency and poor punctuality. To realize a proper allocation of passenger flows and increase train frequency, this paper has proposed an improved urban rail transit scheduling model and solved the model with an adaptive fruit fly optimization algorithm (AFOA). For the benefits of both passengers and operators, the shortest average waiting time of passengers and the least train frequency are chosen as the optimization objective, and train headway is taken as the decision variable in the proposed model. To obtain higher computational efficiency and accuracy, an adaptive dynamic step size is built in the conventional FOA. Moreover, the data of urban rail transit in Zhengzhou was simulated for case study. The comparison results reveal that the proposed AFOA exhibits faster convergence speed and preferable accuracy than the conventional FOA, particle swarm optimization, and bacterial foraging optimization algorithms. Due to these superiorities, the proposed AFOA is feasible and effective for optimizing the scheduling of urban rail transit.

In the study of electromagnetic radiation transmission for large airflow layers, it is found that not all electromagnetic waves are capable of forming waveguide propagation, and have a limit value problem. This is because whether electromagnetic waves propagating in the atmosphere can be captured by the atmospheric waveguide generated under specific meteorological conditions into the waveguide layer, depending on the wavelength (frequency) of the electromagnetic wave, the relative position of the emission source and the evaporating waveguide. And parameters such as the emission angle of the source. When the angle of incidence of the sun and the angle of observation are at a horizontal level, the amplitude of the electromagnetic radiation reflection is not unique. From a mathematical point of view, the limit value is not unique or the limit value is discontinuous, which is called the pseudo limit problem. This electromagnetic transmission pseudo-limit problem is a mathematical physics principle that ignores the physical principles implied in electromagnetic radiation. Based on this background, the paper studies the influencing factors of the pseudo-limit problem of electromagnetic transmission in large airflow layer, and analyzes the mathematical physics principle in the pseudo-limit problem by using Snell’s optical law.

In this paper, we study the synchronization of fractional–order discrete–time chaotic systems by means of two scaling matrices Θ and Φ . The considered synchronization scheme can be tailored to encompass several types of classical synchronization types. We proposed two nonlinear control strategies for the Θ – Φ synchronization of an m –dimensional drive system and an n –dimensional response system, whereby the synchronization dimension d = m and d = n , respectively. Numerical examples are presented to test the findings of the study.

On the basis of the Naheng Reservoir Project, the stress, strain, and deformation of Naheng Reservoir cemented sand and gravel dam are simulated numerical simulation and structural model test. The stress and deformation laws of the dam under the combined load of dead weight and normal water level are analyzed using the structural model test method. Compared with the finite element numerical simulation, the results reflect the stress and deformation distribution law of the dam. Then, the failure mode of the cemented sand and gravel dam can be visualized by using the water load overload method to conduct the structural model failure test, and the failure mode and failure mechanism of the cemented sand and gravel dam can be discussed. The research results lay a foundation for further determining the safety degree analysis of cemented sand and gravel dam.

With the rapid development of e-commerce, collaborative filtering recommendation system has been widely used in various network platforms. Using recommendation system to accurately predict customers’ preferences for goods can solve the problem of information overload faced by users and improve users’ dependence on the network platform. Because the recommendation system based on collaborative filtering technology has the ability to recommend more abstract or difficult to describe goods in words, the research related to collaborative filtering technology has attracted more and more attention. According to the past research, in collaborative filtering algorithm, if Pearson correlation coefficient is used, errors will occur under special circumstances. In this study, the normal recovery similarity measure is used to modify the similarity value to correct the error value of a collaborative filtering recommendation algorithm. Based on this, a big data analysis method based on a modified collaborative filtering recommendation algorithm is proposed. This research implemented it in the cloud Hadoop environment, and measure the execution time with 2, 5 and 8 nodes. Then the research compared it with the execution time of a single machine, and analyze its speedup ratio and efficiency. The experimental results show that the execution time increases with the number of neighbors. When the number of nodes is 5 and 8, the execution time is greatly improved, which improves the efficiency of collaborative filtering algorithm and can cope with massive data in the future.

In practical application, there are a large amount of imbalanced data containing only a small number of labeled data. In order to improve the classification performance of this kind of problem, this paper proposes a semi-supervised learning algorithm based on mixed sampling for imbalanced data classification (S2MAID), which combines semi-supervised learning, over sampling, under sampling and ensemble learning. Firstly, a kind of under sampling algorithm UD-density is provided to select samples with high information content from majority class set for semi-supervised learning. Secondly, a safe supervised-learning method is used to mark unlabeled sample and expand the labeled sample. Thirdly, a kind of over sampling algorithm SMOTE-density is provided to make the imbalanced data set become balance set. Fourthly, an ensemble technology is used to generate a strong classifier. Finally, the experiment is carried out on imbalanced data with containing only a few labeled samples, and semi-supervised learning process is simulated. The proposed S2MAID is verified and the experimental result shows that the proposed S2MAID has a better classification performance.

The paper adopts the financial physics approach to investigate influence of trading volume, market trend, as well as monetary policy on characteristics of the Chinese Stock Exchange. Utilizing 1-minute high-frequency data at various time intervals, the study examines the probability distribution density, autocorrelation and multi-fractal of the Shanghai Composite Index. Our study finds that the scale of trading volume, stock market trends, and monetary policy cycles all exert significant influences on micro characteristics of Shanghai Composite Index. More specifically, under the conditions of large trading volumes, loose monetary policies, and downward stock trends, the market possesses better fitting on Levy’s distribution, the volatility self-correlation is stronger, and multifractal trait is more salient. We hope our study could provide better guidance for investment decisions, and form the basis for policy formulation aiming for a healthy growth of the financial market.

Groundwater is the key factor of determining the growth of vegetation. Identifying the characteristics of groundwater is an important basis to formulate a management plan for water resources and develop the technology of controlling desertification in arid areas scientifically. It is also important to the environmental protection in China. Ground penetrating radar (GPR) signals produce a special response to the changes in water content during propagation, thus it is essential to study the propagation of electromagnetic pulse in aeolian sand with different water content. The GPR tests of aeolian sand samples with different water content were conducted by a GPR system, dielectric constant meter, and conductivity meter. The temporal and frequency spectral characteristics of electromagnetic signals measured from aeolian sand samples were analyzed. The results show that the dielectric constant and conductivity of aeolian sand increase nonlinearly as the water content increases, and the attenuation coefficient of electromagnetic pulses increases parabolically. Meanwhile, the temporal waveform fluctuates significantly at the boundary of different media, and its two-way travel time increases nonlinearly as the water content increases, the pulse velocity decreases nonlinearly. Furthermore, the peak frequency of the spectrum for a signal propagating through aeolian sand decreases as the water content increases. The peak frequency is concentrated in the 1000 to 1400 MHz range, but the shape and bandwidth of the spectrum are less affected by water content. The above-mentioned correlations can provide a water content estimation of aeolian sand with direct value to the local authorities which are involved in the decision-making process for effective water management in arid and semi-arid area.

There are many non-probability factors affecting financial markets and the return on risk assets is fuzzy and uncertain. The authors propose new risk measurement methods to describe or measure the real investment risks. Currently many scholars are studying fuzzy asset portfolios. Based on previous research and in view of the threshold value constraint and entropy constraint of transaction costs and transaction volume, the multiple-period mean value -mean absolute deviation investment portfolio optimization model was proposed on a trial basis. This model focuses on a dynamic optimization problem with path dependence; solving using the discrete approximate iteration method certifies the algorithm is convergent. Upon the empirical research on 30 weighted stocks selected from Shanghai Stock Exchange and Shenzhen Stock Exchange, a multi-period investment portfolio optimum strategy was designed. Through the empirical research, it can be found that the multi-period investments dynamic optimization model has linear convergence and is more effective. This is of great value for investors to develop a multi-stage fuzzy portfolio investment strategy.

To solve the problem of multi-objective performance optimization based on ant colony algorithm, a multi-objective performance optimization method of ORC cycle based on an improved ant colony algorithm is proposed. Through the analysis of the ORC cycle system, the thermodynamic model of the ORC system is constructed. Based on the first law of thermodynamics and the second law of thermodynamics, the ORC system evaluation model is established in a MATLAB environment. The sensitivity analysis of the system is carried out by using the system performance evaluation index, and the optimal working parameter combination is obtained. The ant colony algorithm is used to optimize the performance of the ORC system and obtain the optimal solution. Experimental results show that the proposed multi-objective performance optimization method based on the ant colony algorithm for the ORC cycle needs a shorter optimization time and has a higher optimization efficiency.

The current information retrieval research on industrial clusters has low precision, low recall ratio, obvious delay and high energy consumption. Thus, in this paper, a information retrieval algorithm based on vector space for industrial clusters is proposed. By optimizing the unlawful labels in the database network, dividing the web pages of the industrial cluster information database and calculating the keyword scores of the relevant information of the industrial cluster corresponding to a web page, a set of well-divided database pages is obtained, and the purification of the industrial cluster information database is realized. According to the purification of industrial cluster information database, RFD algorithm is used to extract the page data features of purified industrial cluster information database. The extracted results are substituted into the information retrieval, and the vectors composed of retrieval units are used to describe the information of various types of industrial clusters and each retrieval. The matching results of information retrieval are obtained by calculating the correlation between the information of industrial clusters and the query, and the information retrieval of industrial clusters is completed. Experimental results show that the algorithm has high precision and recall ratio, short retrieval time and low energy consumption.

In FE modeling of port crane structures, errors may be caused due to the simplification of complicated components, unclear physical properties, local approximation and inaccurate boundary conditions. So it is very important to update the FE model accuracy according to the experiment model and results. However there are two major problems when solving the model updating of port crane structure, the one is the difficulty of collecting the structure modal parameters with traditional modal experiment method because of the large scale of port crane structure, the other is mismatching problem while updating processing due to most of the model updating method currently constructing the objective function only by frequency. In this paper, an operational modal analysis is adopted to estimate the modal parameters of port crane structure based on the operational condition. A parametric model updating methodology of finite element (FE) model is proposed to solve port crane structure model updating: a series of design parameters of the FE model of port crane structure are selected as the main factors based on the sensitivity analysis, the objective function is built by considering the frequency correlation and the modal assurance criterion (MAC) together, and finally a zero-order/first-order combination algorithm is utilized to get the final accurate FE model of port crane structure. Research results showed that methodology proposed in this paper has satisfied updating accuracy for port crane structure, which verifies that the proposed method is suitable for model updating problem of this kind of structure.

The relationship between the factors of formation mechanism of stratification and the pedestrian ratio in low-density state has not been analyzed by the existing human flow evacuation simulation method, so that the simulation effect is poor. Thus, the evacuation simulation method for different flow ratios in low-density state is proposed to analyze the walking characteristics of the opposite pedestrians. On the basis of the random deviation grid gas model, the view field of pedestrian is introduced as one parameter. Considering the preference characteristics of pedestrians for the movement of open areas within the view field, the improved random deviation grid gas model is constructed. Through the model, the stratification characteristics of the opposite pedestrian flow in the simple channel scene are simulated. The results show that the proposed method can reproduce the characteristics of non-layering phenomenon of opposite pedestrian flow in low-density state. According to the probability of layer formation, the density of the opposite pedestrian flow is divided into five intervals. The opposite pedestrian flow in the critical density region is metastable, and is susceptible to interference. These results are consistent with the dynamic evolution of the actual opposite pedestrian flow.

In order to implement a computer vision based reading recognition system for pointer gauges, we propose an algorithm to locate the pointer by searching for the minimal bounding rectangle (MBR) of the pointer region. Having determined the center of dial region and the centroids of scale marks, we build up a reference system for reading recognition with the dial region center and the scale mark centroids. To identify the indicating value of a gauge image, we first detect the pointer region based on frame difference, and determine the MBR of the pointer using the longest edge of its convex hull. We then take the centroid of the MBR enclosing the pointer region as the centroid of the pointer. We next take the connection between the pointer centroid to the dial center as the pointer, and calculate the indicating value corresponding to the pointer based on the angle method. Experimental results reveal the effectiveness of the pointer location algorithm in computer vision based reading recognition for pointer gauges.

Separation is the primary consideration in cloud computing security. A series of security and safety problems would arise if a separation mechanism is not deployed appropriately, thus affecting the confidence of cloud end-users. In this paper, together with characteristics of cloud computing, the separation issue in cloud computing has been analyzed from the perspective of information flow. The process of information flow in cloud computing systems is formalized to propose corresponding separation rules. These rules have been verified in this paper and it is shown that the rules conform to non-interference security, thus ensuring the security and practicability of the proposed rules.

This paper constructed an optimizing model on multiple vehicles and multiple goods, which is used in a study on the loading problem for railway freight. We take the maximum utilization coefficient of car loading capacity, volume capacity and layout optimal degree as objective functions. Several major factors in railway transportation have been cited as constraints: center of gravity, non-overlapping freight, transportation circumscription, car marked loading capacity and volume capacity. In order to increase the car utilization coefficient and obtain flat layers in the loading scheme, an improved genetic annealing algorithm is proposed to solve this optimizing model. The proposed algorithm can efficiently obtain a satisfactory loading scheme in railway transportation. At the end, a numerical example shows that the proposed model and algorithm are better than First Fit Algorithm and Neural Network Algorithm in goods loading capacity and volume capacity, the new loading schemes are more flat on each layer.

Traditionally, the binary search method is used to collect the denoising data in the array pixilated CdZnTe nuclear detector. Due to the high dispersion of the data itself, the acquisition efficiency is low and the acquisition result has a large error. A denoising data acquisition algorithm for array pixilated CdZnTe nuclear detector is proposed. The detector principle and system noise type are analyzed. The buffer half-full storage algorithm and multi-thread control method are used to collect the noise data of array pixilated CdZnTe nuclear detector. The experimental data show that the proposed algorithm can effectively collect the denoising data of the array pixilated CdZnTe nuclear detector, and the acquisition error rate is only 0.25, the acquisition speed growth rate is up to 96%, with high acquisition accuracy and efficiency.

The traditional method of cloning formation is used to study the radiation effect of nuclear physics rays on hepatoma cells, and the results obtained are not reliable. Therefore, a new method of studying the radiation effect of nuclear physics rays on hepatoma cells is proposed. PCC method is used to study the radiation effect of γ-rays on hepatoma cells. Radiation effects of X-rays on hepatoma cells were studied by radionuclide formation assay, neutral comet electrophoresis and γH2AX focal detection. The results showed that the survival curves of HepG2 hepatoma cells irradiated by γ-rays were well fitted by linear squares. There was a linear relationship between the survival rate and irradiation dose of HepG2 hepatoma cells irradiated by γ-rays. HepG2 hepatoma cells showed strong tolerance to X-ray irradiation, and the positive rate of γH2AX cells reached 100% in each dose group only 0.5 h after X-ray irradiation.

A qualitative comparison of three, popular and most widely known numerical integration methods in terms of atmospheric single scattering calculations is presented. A comparison of Midpoint, Trapezoidal and Simpson’s Rules taking into account quality of a clear sky generated images is performed. Methods that compute the atmospheric scattering integrals use Trapezoidal Rule. Authors try to determine which numerical integration method is the best for determining the colors of the sky and check if Trapezoidal Rule is in fact the best choice. The research does not only conduct experiments with Bruneton’s framework but also checks which of the selected numerical integration methods is the most appropriate and gives the lowest error in terms of atmospheric scattering phenomenon.

Finding the geodesic path defined as the shortest paths between two points on three-dimensional surface P is a well known problem in differential and computational geometry. Surfaces are not differentiable in a discrete way, hence known geometry algorithms can’t be used directly - they have to be discretized first. Classic algorithms for geodesic distance calculation such as Mitchell-Mount-Papadimitriou method (MMP) are precise but slow. Therefore modern solutions are developed for fast calculations. One of them is Heat Method which approximates such paths with some accuracy. In this paper we propose the extension of Heat Method to reduce the approximation error. A new formula for calculating value of the parameter t (wave propagation time step) which outperforms the original one in terms of mean and median error is presented. Also, correlation between mesh properties and best wave propagation time step as well as influence of variable node spacing on heat map based method were thoroughly analysed.

The purpose of this article is to analyze the efficiency of electricity generation in photovoltaic systems located on the building made on the basis of HIT-IBC cells for multi-family residential buildings. The comparative analysis of the efficiency of electricity generation by photovoltaic (PV) installations made of two cell types -Heterojunction with Intrinsic Thin-layer-Interdigitated Back Contact (HIT-IBC) and classical mono-crystalline silicon (mono-Si) - showed that the efficiency of HIT-IBC cells is 60% higher. These cells were selected for use as photo-voltaic systems located on the building to cover the demand for electricity through an exemplary multi-family residential building, consisting of 35 apartments divided into two, three and four-person households. Considering the previous calculations, in which it was shown that a PV installation made of HIT-IBC cells (PV1) is able to generate 192,75 kWh/(m 2 ·y), annual electricity production was calculated by the indicated photovoltaic installation. It was found that the photovoltaic installation located on the roof of the building, based on HIT-IBC cells, will allow to cover the total electricity demand by a selected multi-family building. In addition, the installation’s payback period of 9 years was calculated, which takes a high place in the lifespan of photovoltaic installations of 20-25 years and thus ensuring the economic efficiency of the adopted technical solutions.

Purpose In recent years, computer simulations have become an innovative approach which enables research in the field of highly complicated physical phenomena and the study of the laws which govern the universe. The proper interpretation of the results of a visual simulation requires the highest quality of the generated image, as every distortion or mistake may have a significant influence on the readability, accuracy and even credibility of the presentation of the results. The aim of this presentation is to determine a model that enables precise quality evaluation of the three-dimensional visual simulations in the field of structural correctness. Design/methodology/approach The developed model is a solution that makes it possible to estimate the quality of stereoscopic image in the context of major three-dimensional structural dysfunctions, namely, vertical parallax, rotation mismatch and scale mismatch. Implementing the wrought theoretical model with the use of cost-effective mechanisms of image feature detection creates a robust method which enables the scalar grade of structural correctness of the studied three-dimensional simulation to be computed. Findings On the basis of the conducted research, in particular, taking into account three-dimensional simulations, it was stated that the formulated model with the developed method provides an efficient, structural quality estimation tool applicable for a wide variety of three-dimensional images. The obtained results indicate that the wrought method has huge potential in the application of high-resolution simulations by enabling a screening test of the structural quality of the stereoscopic view in quasi-real time. Practical implications The developed method may be used both in order to verify the quality of ready-to-use three-dimensional image and also at the stage of the calibration of input parameters of the simulation. Originality/value The paper takes into account the selection of the most significant distortions which occur in visual, three-dimensional simulations providing a cost-effective and versatile tool which allows for the detection and elimination of serious mistakes and dysfunctions as early as at the calibration stage.

The aim of this paper is to develop simplified model for WiFi electromagnetic field propagation. The model can be used in preliminary estimation of WiFi transmitter localization for the purpose of WiFi-based indoor localization. It can be particularly useful when designing structural networks.We have developed a simplified linear model of WiFi electromagnetic field modelling and compared it with the most commonly used, more sophisticated models and with measurement results which were carried out in the laboratory. As demonstrated by the results of measurements conducted using various hardware, the accuracy of this simplified model introduced is similar to the commonly used models, but the number of parameters is lower. Therefore, our model easier to implement in real life conditions. The model presented in this paper enables WiFi electromagnetic field modelling when the exact values of propagation parameters and transmitter characteristics is unknown. This is usually the case at the early stage of structural network design,when exact parameters of building construction materials are not known. As the model is very simple, it does not require much effort to deploy, while its accuracy is sufficient for preliminary WiFi transmitter localization. Simplified models of WiFi electromagnetic field propagation are known, but no comparative research combined with measurements has been done in this field. This paper provides a comparison of different electromagnetic field models which can be applied to WiFi electromagnetic field propagation together with measurement results.

The aim of this paper is to present methods to calculate pupil size based on various parameters, such as: luminance, age, corneal flux density or monocular/binocular effect. These models allow to distinguish pupil dilation caused by the influence of light and other factors such as psychological state of participants.The developed methods were presented based on empirical data. Various researchers estimate their equations based on oculographic data obtained in the course of experiments. The presented plots are based on those equations. Different approaches can be compared to show the difference between particular models.The methods presented in this paper enable a more detailed investigation of the influence of various parameters on the pupil. It can be used to better estimate the influence of light on pupil size. The main changes occurring in pupil size, i.e. contractions and dilation, are caused by light. Other criteria such emotional arousal, cognitive processes or even memory operations can also alter the pupil, among which the decoupling of light is important. The presented approach is distinct from other similar studies because it decouples the pupillary light reflex.

Due to the growing problem of heart diseases, the computer improvement of their diagnostics becomes of great importance. One of the most common heart diseases is cardiac arrhythmia. It is usually diagnosed by measuring the heart activity using electrocardiograph (ECG) and collecting the data as multidimensional medical datasets. However, their storage, analysis and knowledge extraction become highly complex issues. Feature reduction not only enables saving storage and computing resources, but it primarily makes the process of data interpretation more comprehensive. In the paper the new igPCA (in-group Principal Component Analysis) method for feature reduction is proposed. We assume that the set of attributes can be split into subgroups of similar characteristic and then subjected to principal component analysis. The presented method transforms the feature space into a lower dimension and gives the insight into intrinsic structure of data. The method has been verified by experiments done on a dataset of ECG recordings. The obtained effects have been evaluated regarding the number of kept features and classification accuracy of arrhythmia types. Experiment results showed the advantage of the presented method compared to base PCA approach.

The aim of this paper is to present methods for human eye blink recognition. The main function of blinking is to spread tears across the eye and remove irratants from the surface of the cornea and conjuctiva. Blinking can be associated with internal memory processing, fatigue or activation in central nervous system. There are currently many methods for automatic blink detection. The most reliable methods include EOG or EEG signals. These methods, however, are associated with a decrease in the comfort of the examined person. This paper presents a method to detect blinks with the eye-tracker device. There are currently many blink detection methods for this devices. Two popular eye-trackers were tested in this paper. In addition a method for improving detection efficiency was proposed.

Developers of video games and simulations from the day one have been trying to improve visuals of their products. The appearance of the scenes depends to a large extent on the approximation to the physical basis of light behaviour in the environments presented. The best effects in this regard are global illumination. However, it is too computationally expensive. One of the methods to simulate global illumination without a lot of processing is Screen-Space Ambient Occlusion. Many implementations of this technique were created, though few take into account direction and colour of the incoming light. An exception is a technique named SSDO – Screen-Space Directional Occlusion. Unfortunately, it suffers from the same drawbacks as its less realistic cousins, such as noise and banding while also remaining moderately expensive for computation. The main purpose of this paper is to optimize basic SSDO method using technique called Statistical Volumetric Obscurance, enhancing its performance while retaining plausible visual effect.

Nowadays, rasterization is the most common method used to achieve real-time semi-photorealistic effects in games or interactive applications. Some of those effects are not easily achievable, thus require more complicated methods and are difficult to obtain. The appearance of the presented worlds depends to a large extent on the approximation to the physical basis of light behaviour in them. The best effects in this regard are global illumination algorithms. Each of them including ray tracing give the most plausible effects, but at cost of higher computational complexity. Today’s hardware allows usage of ray tracing methods in-real time on Graphics Processing Units (GPU) thanks to its parallel nature. However, using ray tracing as a single rendering method may still result in poor performance, especially when used to create many image effects in complex environments. In this paper we present a hybrid approach for real-time rendering using both rasterization and ray tracing using heuristic, which determines whether to render secondary effects such as shadows, reflections and refractions for individual objects considering their relevancy and cost of rendering those effects for these objects in particular case.

Correct modelling of human muscle is very difficult issue. The digital model can be used for understandig, how the muscle works, what kinds of processes take places during their work. It can be also used for check correctness of animation synteze. Researchers have developed many methods for creating shoulder models. They differ not only in the approach to creating models, but also in applications. In this article, the authors reviewed the methods of modelling muscles and applied these models for possible application in biomechanics.

In order to increase energy efficiency of AC rotating machines, one possibility is the use of Grain-Oriented steel sheets to build stator magnetic circuits in order to reduce iron losses. After presenting the general concept considering a non-segmented-shifted sheets prototype recently developed in our laboratory, a segmented structure is introduced. Experimental comparisons between these structures are performed using static machines. The main results are analysed using Finite Element modelling that leads to extract the particular physical concepts which govern these associations.

The subject of the paper is a three-dimensional analysis of a coupled fluid-thermal and electromagnetic field in permanent magnet synchronous machine that can work at very high temperatures. To obtain the distribution of the airflow and temperature we employed the coupled fluid-thermal model of the machine. This allowed us to check whether the temperature in sensitive elements does not exceed the permissible limits. The analysis took into account the effect of the color and the smoothness of the machine housing on the temperature distribution in its interior. The influence of design on the temperature distribution and distribution of hot spots was tested. Two topologies are studied considering magnet mounted on the rotor surface or buried in the rotor soft magnetic core. The simulation results were compared with measurements made on a prototype.

The electromagnetic noise generated by the Maxwell radial pressure is a well-known consequence. In this paper, we present an analytical tool that allows air gap spatio-temporal pressures to be obtained from the radial flux density created by surface permanent magnet synchronous machines with concentrated winding (SPMSM). This tool based on winding function, a global air-gap permeance analytical model and total magnetomotive force product, determines the analytical air-gap spatio temporal and spectral radial pressure.We will see step-by-step their impacts in generating noise process. Also two predictive methods will be presented to determine the origin of the lows radial pressure orders noise sources. The interest lies in keeping results very quickly and appropriate in order to identify the low order electromagnetic noise origin. Then through an inverse approach using an iterative loop a new winding function is proposed in order to minimize radial force low order previously identified and chosen.

The paper analyzes a possible improvement of Pulse Width Modulation (PWM) fed motor insulation according to a principle developed by the high voltages industry. The proposed principle consists in using a specific enameled wire made with an additional semi-conductive layer on its outer surface. Experimental study is realized in order to measure Partial Discharges (PDs) activity with three technologies: Classical enameled wire, enameled wire with an external conductive layer (silver paint) and enameled wire with an external semi-conductive layer (2% of carbon nanoparticles). Simulations are made in order to understand the behavior of the new semi-conductive wire.

The paper presents the design of a machine that can work at high temperature. The impact of various topologies and materials on electromagnetic field distribution and losses was analyzed. Two and three-dimensional simulations were carried out. The results obtained were discussed.

This study defines a monitoring method based on impedance analysis in the upper part of the spectrum. It focuses on the analysis of the high frequency behavior of electrical machines windings considering the turn-to-turn capacitance variations (delta-C) due to insulation aging. An equivalent circuit is automatically generated from the turn arrangements in coils; parameters are computed considering the coil shape and the characteristics of insulation materials. PSpice analysis of the equivalent circuit yields the resonance frequencies to be monitored. With this software and a database giving the relationship between the turn-to-turn capacitance variation delta-C and the reduction of insulation performances due to aging, it is possible to build a monitoring system able to produce an alert when the probability of failure becomes higher than a predetermined level.

The paper deals with a high frequency model of inorganic coils used to build high temperature (HT ∘ ) motor. The HT ∘ wire has a nickel layer that protects the copper against oxidation and a thin inorganic coating, which has poor electrical and mechanical properties. Therefore, the coils must be designed with a special care for getting a good distribution of turn-to-turn voltage during the fast transients excited by the steep fronted voltages of the PWM inverter.A specific coil structure is proposed and a high frequency (HF) equivalent circuit able to compute the turn-to-turn voltages during transients. The voltage distribution between the coils of a stator phase is also detailed.

This paper introduces a new concept for integrated electrical motor drives (IEMD) with the aim of minimizing the number of inverter’s power switching components. The latter is switched reluctance motor (SRM) based. The control strategy is jointly designed, inspired by Flyback power supplies operating at very high frequencies. A simple case study on an 8/6 SRM has been carried out. The study enables to highlight most challenging problems that have to be overcome in future works: overvoltages during switching due to the flux leakage, and the efficiency of the magnetic material constituting the machine at high switching frequencies. This concept turns out to be an interesting basis for a very advanced integration of the switching structure within electrical machines.

Free surface electrospinning is a continuous electrospinning method for low-cost, massive production of nanofibers. The interjet distance λ is a critical parameter in free surface electrospinning, which directly determines the nanofiber production efficiency. In this investigation, we studied the interjet distance during free surface electrospinning based on electrohydrodynamic instability theoretically and experimentally, with special interest focused on the effect of surface tension and electric field intensity on the interjet distance. The experimental results indicated that the critical parameters affecting the interjet distance were the surface tension and applied voltage, which was in good compliance with the theoretical prediction. The relationship between interjet distance λ and surface tension followed an allometric law with positive exponential function, and the relationship between interjet distance λ and applied voltage followed an allometric law with negative exponential function. The present results can be used to understand the basic parameters which determine the interjet distance in free surface electrospinning.

In this paper, the energy dissipation in a bolted lap joint is studied using a continuum microslip model. Five contact pressure distributions compliant with the power law are considered, and all of them have equal pretension forces. The effects of different pressure distributions on the interface stick-slip transitions and hysteretic characteristics are presented. The calculation formulation of the energy dissipation is introduced. The energy dissipation results are plotted on linear and log-log coordinates to investigate the effect of the pressure distribution on the energy distribution. It is shown that the energy dissipations of the lap joints are related to the minimum pressure in the overlapped area, the size of the contact area and the value of the power exponent. The work provides a theoretical basis for further effective use of the joint energy dissipation.

Samples of 1Cr12Ni3Mo2V-based composites with different TiC contents (The volume fraction of TiC were 0%, 10%, 20%, 30%, 40%) were prepared based on laser solid forming. Thermodynamic analysis was performed to estimate the possible chemical reactions. Phase analysis and microscopic topography analysis were characterized by optical microscopy (OM), scan electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDS). Finally, the formation mechanism of microscopic appearance was analyzed. The results indicate that the TiC particles were successfully dispersed in the matrix. TiC particles mainly exist in two ways in the matrix. The large particles were not completely melted and the small particles were decomposed and then precipitated. Their shape was mainly cross, plum-shaped or dendritic distribution with different TiC contents.

Nano-TiO 2 film attracts great attention by its excellent photocatalytic activity performance. The application of nano-TiO 2 film based on fabric substrate in indoor household textiles is helpful for purifying air and degrading formaldehyde content in indoor environments. In this paper, the nano-TiO 2 films were prepared on fiberglass substrate by the sol-gel method, and the appearance of fabrics coated with nano-TiO 2 at conditions of both without calcination (room temperature) and high temperature calcination (300 ∘ C, 350 ∘ C, 400 ∘ C) was studied. In addition, X-ray diffraction technology was applied to analyze the crystallization of TiO 2 film, with further discussion of the photocatalytic performance of degrading helianthin under UV irradiation.The results show that with increase of calcination temperature, the color of the fabric gets darker and darker until the powder peeling and dyeing reaches the maximum degree, the fabric becomes fragile, the anatase crystal form of TiO 2 film tends to be complete, and the photocatalytic performance is improved. It is feasible to apply TiO 2 film on the surface of fabrics in the design of indoor household textiles.

The effects of the single and compound addition of rare earth Gd and Er on corrosion resistance and residual strength of as-cast AM50 magnesium alloy were studied using XRD, SEM, EDS, the weightlessness test, electrochemistry method, and tensile test. The results of XRD and SEM showed that Al 3 Er, Al 2 Gd 3 , and Al–Mn–Gd(Er) phases appeared in the alloy structure after the addition of rare earth Er and Gd. The results from the weightlessness test and Tafel curves show that the corrosion resistance of the modified composite rare earth was improved. Stress concentration caused by a corrosion pit is the direct cause of the tensile samples after corrosion. The corrosion residual strength of modified composite rare earth specimens is better than that of modified single rare earth samples. Fracture analysis indicates that the addition of rare earth elements did not change the fracture mechanism of the alloy, and the fracture was still the cleavage fracture.

In order to improve quality and reveal the law of precision forging, closed-die forging technology is used in this paper to conduct a numerical analysis of the forming process of aluminum alloy connecting rod by the DEFORM software. Forming effects under different loading modes were acquired, and forming process, blank flow characteristics, stress-strain distribution and load-stroke curve characteristics were analyzed. Study results indicate that the forming effect under the loading mode featuring first movement of lateral punch and then movement of upper and lower punches is good with high quality forge piece and no defect, the closed-die forging technology of aluminum alloy connecting rod is reasonable and feasible. Under a certain deformation velocity and deformation mode, aluminum alloy connecting rod forming load firstly reduces and then increases, the forming load is in direct proportion to deformation velocity. When the forming process is finished, forming load reaches 130T, it accords with the production practice. The study results provide a certain reference for guiding the formulation of closed-die forging production technology of aluminum alloy connecting rods.

This paper aims to solve two problems of the sandwich panel with aluminum honeycomb: material parameters solution and shape control. The accurate material parameters of the sandwich panels are the basis of shape control. Therefore, a mixed numerical-experimental method is proposed to inversely solve equivalent material parameters of the sandwich panel using genetic algorithm (GA) in the first place. Then a high efficiency FE model based on equivalent material parameters is established to study shape control of the sandwich panels. For shape control, the key issue aims to search optimum position and adjustment volume of control points where actuators are installed. Toward the end, the FE simulation method is deployed to optimize actuator position and adjustment volume one by one. Finally, an active control platform based on multi-point adjustment is developed to verify the practicability of the approach proposed in this paper. Through the experiment of shape control, the root mean square (RMS) of surface deviation of sandwich panel is decreased from 62.7μm to 15.5μm. The results show that the shape control can significantly improve the surface accuracy of the sandwich panels, and the validity of equivalent material parameters is also proved from the side.

With the continuous development of metal manufacturing technology, high-strength and high-hardness ductile iron materials have excellent comprehensive performance. Many performance indexes are comparable to those of alloy steels, and they have excellent casting properties. Many large-scale parts produced by cast steel are slowly being replaced by this material. Ductile iron is obtained by a spheroidizing treatment and inoculation to obtain spheroidal graphite. The mechanical properties of cast iron have been effectively improved, especially plasticity and toughness, and the strength obtained is higher than that of carbon steel. Ductile iron has the properties of iron and the properties of steel. It is a new type of engineering material with high plasticity, strength, corrosion resistance, and wear-resistance. Because of its excellent performance, it has been successfully used to cast parts with high-stress conditions, high strength, toughness and wear resistance. Due to the small splitting effect of ductile iron on the metal matrix, the stress concentration is effectively eliminated. Therefore, the matrix structure of ductile cast iron is changed by heat treatment, thereby improving its mechanical properties and the damping performance of the material itself. Through a heat treatment process experiment of ductile iron, the related process and technical measures of damping performance in the heat treatment production process are obtained.

The effect of austenitising heat treatment on the microstructure, hardness and metal release of the nitrogen bearing, martensitic stainless steel 420U6 was investigated. The heat treatment was carried out at temperatures between 950 to 1,150 ∘ C with a holding time between 30 to 120min, followed by air cooling. The quenched microstructures observed by a scanning electron microscope indicated that by increasing the austenitising temperature and holding time, the number of carbides decreases while the grain size and the amount of retained austenite increases. For a given holding time, the hardness increases to a peak and then decreases continuously with the increase of temperature. The metal release test, according to the GB 4806.9-2016 standard, reveals that the metal release concentration is highly affected by the austenitising temperature. The parameters of the austenitising heat treatment, which can achieve the optimum combination of hardness and metal release, were obtained.

This paper presents an efficient thermo-elastoplastic method for the prediction of welding-induced distortions in a large panel structure. It is based on a shell/3D modeling technique which was proposed and experimentally validated in the authors’ previous study. Two numerical examples are analyzed to evaluate the accuracy and efficiency of the present method. In the first example, the recommendations for the estimation of the minimum 3D zone size in the shell/3D model reported in the authors’ previous work are verified, in comparison with the full 3D model, on a T-joint model consisting of plates with different thicknesses. It is shown that the shell/3D modeling technique provides a significant reduction in the computational time needed for the simulation of the welding process and thus enables efficient thermo-elastoplastic analyses on large structures. In the second example, the proposed model is validated on a large panel structure by corresponding the experimental data and inherent strain solutions from the literature.

In the present work, a transient full-coupled modelling approach has been put forward to study the effect of electrode tip on formation of metal droplets and temperature profile in the electromagnetically-controlled electroslag-remelting furnace with vibrating electrode. The electromagnetic field, momentum and energy conservation equations are solved simultaneously based on the finite volume method. The interface of slag and metal is traced using the volume of fluid approach. The results show that in the case of cone tip electrode the average dimension of metal droplets is smaller compared to the flat tip electrode. In addition, the bigger and stretched metal droplets are not observed with the cone tip electrode. The temperature fields with the cone tip electrode are distributed in a prominent periodic pattern compared to the case with flat tip electrode. The maximum temperature zone with the cone tip electrode is located along the z axial in the upper part of slag, not in the lower part. When the frequency changes from 0.17 Hz to 1 Hz, the maximum temperature reduces from 2050 K to 1985 K and the peak value of velocity decreases from 0.20 m/s to 0.125 m/s. When the vibration amplitude varies from 3mm to 6mm, the maximum temperature in the slag cover drops by 3.9% and the peak value of velocity rises by 16.7%.

In order to clarify the dependence relationship between the heat storage & preservation wall and the thermal environment, and to provide data base and theory foundation for the north wall construction of the Chinese solar greenhouse (CSG), the experimental measures has been employed to investigate the distributions of temperature, humidity and heat transfer of three different wall materials ( i.e . perforated brick, fine coal ash brick, common clay brick). The dynamic variations of the heat-storage and heat-release processes were identified, and the thermal response characteristics were discussed. The effect of north wall materials on the thermal environment of the solar greenhouse in northern China was revealed. The results indicated that the daily heat-storage and heat-release of fine coal ash brick wall can reach ϕ imput = 34.5~130.6 W·m −2 and ϕ output = −24.15~-45 W·m −2 , respectively. The daily heat-storage time can reach t = 5~8 h, and the wall temperature at night can be 3~4 ∘ C higher than the air temperature. Moreover, the maximum indoor temperature of the fine coal ash brick wall can be maintained at t ≤ 16.7 ≤ 31.1 ∘ C, the minimum humidity can be maintained at 29.75~45%. Fortunately, the construction cost is moderate, while the physical properties are obviously better than those of perforated brick and common clay brick in the CSG. The overall thermal performance of fine coal ash brick is the best of the three north wall materials, and it can make the most advantage of the heat-storage and heat-preservation performances of the CSG. As a consequence, the fine coal ash brick wall of the solar greenhouse has good promotion value in northern China and other high latitude, high altitude and long winter regions.

Cooling technology is widely applied in modern turbines to protect the turbine blades, and extracting high-pressure cooling air from a compressor exerts a remarkable influence on the gas-turbine performance. However, the three-dimensional optimal design of a turbine in modern industrial practice is usually carried out by pursuing high component efficiency without considering possible changes in coolant requirement; hence, it may not exactly lead to improvement in the gas-turbine cycle efficiency. In this study, the turbine stator was twisted and leaned to achieve higher comprehensive efficiency, which is the cycle-based efficiency definition for a cooled turbine that considers both turbine aerodynamic performance and coolant requirement. First, the influence of twist and compound lean on turbine aerodynamic performance, considering stator-hub leakage, was investigated. Then, a method to predict the coolant requirement for turbines with different stator designs was applied, to evaluate coolant-requirement change at the design condition. The optimized turbines were finally compared to demonstrate the necessity of considering the coolant-requirement change in the optimal design. This indicated that proper twisting to open the throat area in the stator hub and compound lean to the pressure surface side could help improve the cooled-turbine comprehensive efficiency.

The limited durability of hydrogen fuel cells is one of the main obstacles in their wider adoption as a clean alternative technology for small scale electricity production. The Ostwald ripening of catalyst material is recognized as one of the main unavoidable degradation processes deteriorating the fuel cell performance and shortening its lifetime. The paper systematically studies how the modeling approach towards the electrochemically driven Ostwald ripening in the fuel cell catalyst differs from the classical diffusion driven models and highlights how these differences affect the resulting evolution of particle size distribution. At moderately low electric potential, root-law growth of mean particle size is observed with linear relation between mean particle size and standard deviation of particle size distribution, similar to Lifshitz-Slyozov-Wagner theory, but with broader and less skewed distribution. In case of high electric potential, rapid particle growth regime is observed and qualitatively described by redeposition of platinum from a highly oversaturated solution, revealing the deficiencies of the existing platinum degradation models at describing the Ostwald ripening in the fuel cells at high electric potentials. Several improvements to the established models of platinum degradation in fuel cell catalysts are proposed, aimed at better description of the diffusion processes involved in particle growth due to Ostwald ripening.

This paper experimentally investigates heat dissipation of a heat pipe with phase change materials (PCMs) cooling in a multiple heat source system. Two heat sources are fixed at one end of the heat pipe. Considering that a heat sink cannot dissipate all the heat generated by two heat sources, various PCMs are used due to a large latent heat. Different materials in a container are wrapped outside of the middle heat pipe to take away the heat from the evaporation section. The experimental tests obtain temperature data of heat source, evaporation section, and energy storage characteristics of PCMs are also determined under constant and dynamic values of the heat source powers. It is found that under this multiple heat source system structure, the phase change material RT35 maintains temperature variations of the evaporation section at a lower temperature and shortens the required time to reach the equilibrium temperature under a heating power of 20 W.

The membrane-based wet electrostatic precipitator (MWESP), exhibiting good control of PM 2 .5, has more and more widely applications. Considering traditional flexible collectors’ poor rigidity, this paper presents two modified composite collectors (MCC), smooth PVC plates covered by carbon fiber and glass fiber respectively. This paper tries to make a comparative study of performance characteristic between both the MCCs and a same size smooth PVC collector. We compared the collectors in the aspects as follows: water film thickness, ionic concentration,V-I characteristic and dust collection efficiency. Firstly, we compared the three collectors’ film forming abilities through a water film thickness measure experiment. Secondly, we measured the ionic concentrations and V-I characteristics, getting the electrical characteristics of the three collectors. At last, through an experiment of collection efficiencies, we compared the three collectors’ performance characteristics. The experiment results indicate that MCC with glass fiber not only can guarantee the rigidity of collector, but also proves best wetting properties and best performance characteristic with the water flow rate of 700L/h.

Soot prediction for diesel engines is a very important aspect of internal combustion engine emissions research, especially nowadays with very strict emission norms. Computational Fluid Dynamics (CFD) is often used in this research and optimisation of CFD models in terms of a trade-off between accuracy and computational efficiency is essential. This is especially true in the industrial environment where good predictivity is necessary for engine optimisation, but computational power is limited. To investigate soot emissions for Diesel engines, in this work CFD is coupled with chemistry tabulation framework and semi-empirical soot model. The Flamelet Generated Manifold (FGM) combustion model precomputes chemistry using detailed calculations of the 0D homogeneous reactor and then stores the species mass fractions in the table, based on six look-up variables: pressure, temperature, mixture fraction, mixture fraction variance, progress variable and progress variable variance. Data is then retrieved during online CFD simulation, enabling fast execution times while keeping the accuracy of the direct chemistry calculation. In this work, the theory behind the model is discussed as well as implementation in commercial CFD code. Also, soot modelling in the framework of tabulated chemistry is investigated: mathematical model and implementation of the kinetic soot model on the tabulation side is described, and 0D simulation results are used for verification. Then, the model is validated using real-life engine geometry under different operating conditions, where better agreement with experimental measurements is achieved, compared to the standard implementation of the kinetic soot model on the CFD side.

Recently, investigations on building thermal inertia are mainly involved with the materials of the building envelope. Usually, other influencing factors are ignored, such as room ventilation, indoor heat storage, indoor cold source, indoor heat source and human behavior. In this paper, two models based on thermodynamics are given to evaluate building thermal performance. One is thermal mass model, and the other one is thermal reserve coefficient model. Based on thermal response testing data in a non-heating season, the thermal mass model was adopted to classify the envelope type, and the delay rules between the indoor temperature and the outdoor meteorological parameters are analyzed. In a heating season, the delay rules among the outdoor temperature, indoor temperature and supply water temperature are obtained by changing the supply water temperature. Thermal performance of the targeted building is evaluated with the thermal reserve coefficient model. For the same public building, two evaluation models tend to be consistent. These two evaluation models presented in this paper can be applied for the optimal design of buildings envelope.

Normal operation of gas turbines will be affected by deposition on turbine blades from particles mixed in fuels. This research shows that it is difficult to monitor the mass of the particles deposition on the wall surface in real time. With development of electronic technology, the antenna made of printed circuit board (PCB) has been widely used in many industrial fields. Microstrip antenna is first proposed for monitoring particles deposition to analyse the deposition law of the particles accumulated on the wall. The simulation software Computer Simulation Technology Microwave Studio (CST MWS) 2015 is used to conduct the optimization design of the PCB substrate antenna. It is found that the S 11 of vivaldi antenna with arc gradient groove exhibits a monotonous increase with the increase of dielectric layer thickness, and this antenna is highly sensitive to the dielectric layer thickness. Moreover, a cold-state test is carried out by using atomized wax to simulate the deposition of pollutants. A relationship as a four number of times function is found between the capacitance and the deposited mass. These results provide an important reference for the mass detection of the particle deposition on the wall, and this method is suitable for other related engineering fields.

In this paper, the atomization characteristics of an effervescent atomizer were investigated. The velocity, Sauter Mean Diameter ( SMD ) and atomization cone angle of the droplets were measured using the Phase Doppler Analyzer (PDA) to discuss the effect of different design parameters. The results showed that the atomization was unstable at a small Gas-Liquid Rate ( GLR ) while the atomization proved gradually by increasing the GLR . The optimal atomization region was at a GLR =0.1. In the atomization process, there existed a typical velocity distribution for the swirl atomizer. The design parameters of atomizer provided a great influence on the Sauter Mean Diameter ( SMD ) and atomization cone angle. The experiment results showed that some droplets had negative velocities.