Diagnostics and decomposition of atmospheric disturbances in a planar flow are considered in this work. The study examines a situation in which the stationary equilibrium temperature of a gas may depend on the vertical coordinate due to external forces. The relations connecting perturbations are analytically established. These perturbations specify acoustic and entropy modes in an arbitrary stratified gas affected by a constant mass force. The diagnostic relations link acoustic and entropy modes, and are independent of time. Hence, they provide an ability to decompose the total vector of perturbations into acoustic and non-acoustic (entropy) parts, and to establish the distribution of energy between the sound and entropy modes, uniquely at any instant. The total energy of a flow is hence determined in its parts which are connected with acoustic and entropy modes. The examples presented in this work consider the equilibrium temperature of a gas, which linearly depends on the vertical coordinate. Individual profiles of acoustic and entropy parts for some impulses are illustrated with plots.
A computer model EUSS (Emission Uniformity on Sloping Surfaces) has been developed to design and evaluate the system capacity under operating conditions for drip irrigation system. And achieve the desired value of emission uniformity that is not significantly different according to the recommended values by applying it in field experiment located at Al- -Slahia city, Egypt. The model has the ability to design the system by all of the common design techniques and have ability to customize any of them.
EUSS model includes two main parts: crop water requirements, and hydraulic calculations of the system using metric unit system. It developed in graphical user interface of the programming language C-sharp (C#) by using Microsoft Visual Studio. The model database is containing the equations, tables and reference values to get more rapid and accurate results, and gives the opportunity for selecting some parameters such as: soil properties, characteristics of the corresponding crop, and climatic data. EUSS model allows the user to assume or set definite values, for example plot layout, land slopes and topography, the emitter characteristics and operating conditions.
This paper presents a novel low-complexity soft demapping algorithm for two-dimensional non-uniform spaced constellations (2D-NUCs) and massive order one-dimensional NUCs (1D-NUCs). NUCs have been implemented in a wide range of new broadcasting systems to approach the Shannon limit further, such as DVB-NGH, ATSC 3.0 and NGB-W. However, the soft demapping complexity is extreme due to the substantial distance calculations. In the proposed scheme, the demapping process is classified into four cases based on different quadrants. To deal with the complexity problem, four groups of reduced subsets in terms of the quadrant for each bit are separately calculated and stored in advance. Analysis and simulation prove that the proposed demapper only introduces a small penalty under 0.02dB with respect to Max-Log-MAP demapper, whereas a significant complexity reduction ranging from 68.75% to 88.54% is obtained.
In this work, steady flow-field and heat transfer through a copper-water nanofluid around a rotating circular cylinder, dissipating uniform heat flux, with a constant non-dimensional rotation rate varying from 0 to 5 was investigated numerically using a finite-volume method for Reynolds numbers from the range 10–40. Furthermore, the range of nanoparticle volume fractions considered is 0–5%. The variation of the local and the average Nusselt numbers with Reynolds number, volume fractions, and rotation rate are presented for the range of conditions. The average Nusselt number is found to increase with increasing the nanoparticle volume fractions and decrease with increasing value of the rotation rate.
In this paper the authors present the test carried out to obtain the uniform velocity distribution at the outlet cross section of flow fan. In the investigations the inner flat vane mounted inside of the impeller has been applied. For various angular position of the inner vane, one obtained different flow structures as well as different velocity distributions. The analysis of the obtained results is presented in form of graphs shown in 10 figures, juxtaposing flow phenomena with velocity distributions. Numerical flow simulation with the use of Flo++ program based on the Finite Volume Method was carried out.
In recent years, many scientific and industrial centres in the world developed a virtual reality systems or laboratories. The effect of user “immersion” into virtual reality in such systems is largely dependent on optical properties of the system. In this paper, problems of luminance distribution uniformity in CAVE-type virtual reality systems are analyzed. For better characterization of CAVE luminance nonuniformity corner and edge CAVE nonuniformity were introduced. Based on described CAVE-type virtual reality laboratory, named Immersive 3D Visualization Lab (I3DVL) just opened at the Gdansk University of Technology, luminance nonuniformity of the system is evaluated and discussed. Data collection of luminance distribution allows for software compensation of intensity distribution of individual images projected onto the screen (luminance non-uniformity minimization) in the further research.
In this research work, high uniform CuFeS2 chalcopyrite with 20-40 nm particles were synthesized via a simple hydrothermal method. Different analysis were used to characterize the obtained product such as X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and thermal gravimetric analysis (TGA). The photocatalytic activity of the product was investigated by degradation three different dyes namely acid brown, acid red and methylene blue. The results showed the synthesized CuFeS2 nanoparticles have high photocatalytic activity and can degrade the used dyes in large quantities.
In this study, free and forced vibration responses of carbon nanotube reinforced uniform and tapered composite beams are investigated. The governing differential equations of motion of a carbon nanotube (CNT) reinforced uniform and tapered composite beams are presented in finite element formulation. The validity of the developed formulation is demonstrated by comparing the natural frequencies evaluated using present FEM with those of available in literature. Various parametric studies are also performed to investigate the effect of aspect ratio, percentage of CNT content, ply orientation, and boundary conditions on natural frequencies and mode shapes of a CNT reinforced composite beam. It was observed that the addition of carbon nanotube in fiber reinforced polymer composite (FRP) beam enhances the stiffness of the structure which consequently increases the natural frequencies and alters the mode shapes.
The goal of this paper is to explore and to provide tools for the investigation of the problems of unit-length scheduling of incompatible jobs on uniform machines. We present two new algorithms that are a significant improvement over the known algorithms. The first one is Algorithm 2 which is 2-approximate for the problem Qm|pj = 1, G = bisubquartic|Cmax. The second one is Algorithm 3 which is 4-approximate for the problem Qm|pj = 1, G = bisubquartic|ΣCj, where m ∈ {2, 3, 4}. The theory behind the proposed algorithms is based on the properties of 2-coloring with maximal coloring width, and on the properties of ideal machine, an abstract machine that we introduce in this paper.
The work deals with experimental and numerical thermodynamic analyses of cross-flow finned tube heat exchangers of the gas-liquid type. The aim of the work is to determine an impact of the gas non-uniform inlet on the heat exchangers performance. The measurements have been carried out on a special testing rig and own numerical code has been used for numerical simulations. Analysis of the experimental and numerical results has shown that the range of the non-uniform air inlet to the considered heat exchangers may be significant and it can significantly affect the heat exchanger efficiency.
Non−uniformity noise, it was, it is, and it will probably be one of the most non−desired attached companion of the infrared focal plane array (IRFPA) data. We present a higher order filter where the key advantage is based in its capacity to estimates the detection parameters and thus to compensate it for fixed pattern noise, as an enhancement of Constant Statistics (CS) theory. This paper shows a technique to improve the convergence in accelerated way for CS (AACS: Acceleration Algorithm for Constant Statistics). The effectiveness of this method is demonstrated by using simulated infrared video sequences and several real infrared video sequences obtained using two infrared cameras
Complex structures used in various engineering applications are made up of simple structural members like beams, plates and shells. The fundamental frequency is absolutely essential in determining the response of these structural elements subjected to the dynamic loads. However, for short beams, one has to consider the effect of shear deformation and rotary inertia in order to evaluate their fundamental linear frequencies. In this paper, the authors developed a Coupled Displacement Field method where the number of undetermined coefficients 2n existing in the classical Rayleigh-Ritz method are reduced to n, which significantly simplifies the procedure to obtain the analytical solution. This is accomplished by using a coupling equation derived from the static equilibrium of the shear flexible structural element. In this paper, the free vibration behaviour in terms of slenderness ratio and foundation parameters have been derived for the most practically used shear flexible uniform Timoshenko Hinged-Hinged, Clamped-Clamped beams resting on Pasternak foundation. The findings obtained by the present Coupled Displacement Field Method are compared with the existing literature wherever possible and the agreement is good.
The performance of majority engineering systems made of composite laminates can be improved by increasing strength to weight ratio. Variable thickness approach (VTA), in discrete form, used in this study is capable of finding minimum laminate thickness in one stage only, instead of two stage methodology defined by other researchers, with substantial accuracy for the given load conditions. This minimum required laminate thickness can be used by designers in multiple ways. Current study reveals that effectiveness of VTA in this regard depends on ply thickness increment value and number of plies. Maximum Stress theory, Tsai Wu theory and Tsai Hill theory are used as constraints, while ply angles, ply thicknesses and number of plies in discrete form are used as design variables in current simulation studies. Optimization is carried out using direct value coded genetic algorithm. The effect of design variables such as ply angles, ply thicknesses and number of plies in discrete form on optimum solution is investigated considering Uniform Thickness Approach (UTA) and Variable Thickness Approach (VTA) for various load cases.