BOUNDARY ELEMENT ANALYSIS OF GREEN AND LINDSAY THEORY UNDER THERMAL AND MECHANICAL SHOCK IN A FINITE DOMAIN

A boundary element formulation based on the Laplace transform method is developed for transient coupled thermoelasticity problems with relaxation times in a two-dimensional finite domain. The dynamic thermoelastic model of Green and Lindsay is selected for the present study. The Laplace transform method is applied to the time domain, and the resulting equations in the transformed field are discretized using the boundary element method. The nodal dimensionless temperature and displacements in the transformed domain are inverted to obtain the actual physical quantities using the numerical inversion of the Laplace transform method. This work considers the Green and Lindsay theory of thermoelasticity with the thermal and mechanical loading in a finite domain. The creation and propagation of elastic and thermoelastic waves in a finite domain and their effects on each other are investigated. Different relaxation times are chosen to briefly illustrate the events that take place in GL theory. Details of the formulation and numerical implementation are also presented.     

Multi-criteria Decision-making Approach for Environmental Impact Assessment to Reduce the Adverse Effects Of Dams

Water Resources Management - Environmental Impact Assessments (EIAs) of development projects are necessary to minimize negative impacts and maximize benefits. The objective of this paper is to...     

The ISM Equation of State Applied to Refrigerants

In this work, we apply an equation of state based on statistical–mechanical perturbation theory to liquid refrigerants and their mixtures. Three temperature-dependent parameters are needed to use the equation of state: the second virial coefficient, B ₂(T), an effective van der Waals covolume, b(T), and a scaling factor, (T). The second virial coefficients are calculated from a correlation based on the heat of vaporization, H _vap, and the liquid density at the freezing point, _fp. (T) and b(T) can also be calculated from the second virial coefficient by a scaling rule. Based on the theory, these two temperature-dependent parameters depend only on the repulsive branch of the potential function, and therefore, by our procedure, can be found from H _vap and _fp. The theory has considerable predictive power, since it permits the construction of the p–v–T surface from the heat of vaporization plus the triple-point density. The equation of state is tested for pure, two- and three-component liquid refrigerant mixtures.     

Effect of galvanic contact on the flotability of galena in the presence and absence of a collector

In this paper, the effect of various electrochemical environments in the galena flotation is investigated. The electrochemical environments consisted of a ball mill for grinding of galena ore and a Denver flotation cell for flotation of galena in the laboratory scale. In order to achieve the maximum recovery with sodium hyposulfite, the concentrations of 0.06 and 0.12 M of air and nitrogen gases have been used to control the pulp potential in the Denver flotation cell. The galena sample was from the “Era mine” which is located in the Kiyasar area, north of Iran. This mine contains: Galena (PbS) at least 22%, Fluorite (CaF₂) 73.37%, Quartz (SiO₂) 2.54% and other minerals such as Cerussite (PbCO₃) and Kaolinite (Al₂Si₂O₅(OH)₄). Flotation of Galena was conducted in a 0.12 M of sodium hyposulfite solution. It was found that the amount of recovery by this process was 85% and 63% in the presence and absence of potassium amyl xanthate (KAX) and at an estimated potential of 280 to 350 mV respectively while the recovery was 70% and 52% at an approximate potential of 175 to 210 mV in water in the presence and absence of collector (KAX).     

The Shape Boltzmann Machine: A Strong Model of Object Shape

A good model of object shape is essential in applications such as segmentation, detection, inpainting and graphics. For example, when performing segmentation, local constraints on the shapes can help where object boundaries are noisy or unclear, and global constraints can resolve ambiguities where background clutter looks similar to parts of the objects. In general, the stronger the model of shape, the more performance is improved. In this paper, we use a type of deep Boltzmann machine (Salakhutdinov and Hinton, International Conference on Artificial Intelligence and Statistics, 2009) that we call a Shape Boltzmann Machine (SBM) for the task of modeling foreground/background (binary) and parts-based (categorical) shape images. We show that the SBM characterizes a strong model of shape, in that samples from the model look realistic and it can generalize to generate samples that differ from training examples. We find that the SBM learns distributions that are qualitatively and quantitatively better than existing models for this task.     

High-speed GPU implementation of a secret sharing scheme based on cellular automata

The Journal of Supercomputing - Parallel implementation provides a solution for the problem of accelerating cellular automata (CA)-based secret sharing schemes and make them appropriate for bulk...     

A new homotopy perturbation method for solving systems of partial differential equations

In this paper, a new homotopy perturbation method (NHPM) is introduced for obtaining solutions of systems of non-linear partial differential equations. Theoretical considerations are discussed. To illustrate the capability and reliability of the method three examples are provided. Comparison of the results of applying NHPM with those of applying HPM reveal the effectiveness and convenience of the new technique.     

Inventory lot-sizing with supplier selection using hybrid intelligent algorithm

In supply chain management (SCM), multi-product and multi-period models are usually used to select the suppliers. In the real world of SCM, however, there are normally several echelons which need to be integrated into inventory management. This paper presents a hybrid intelligent algorithm, based on the push SCM, which uses a fuzzy neural network and a genetic algorithm to forecast the rate of demand, determine the material planning and select the optimal supplier. We test the proposed algorithm in a case study conducted in Iran.     

Messverfahren zur Überprüfung randschichtnaher Veränderungen des Werkstoffzustandes als Folge mechanischer Oberflächenbehandlungen

Zur Charakterisierung der ermüdungsrelevanten Werkstoffveränderungen infolge hochfrequenter Schweißnahtnachbehandlung hat sich der Einsatz von mikromagnetischen Werkstoff‐ und Spannungsanalysen vorteilhaft gezeigt. Für Standardbauteile hat sich gezeigt, dass die Qualitätssicherung der Nachbehandlung mit höherfrequenten Hämmerverfahren bei Einhaltung der Behandlungsparameter durch eine Sichtkontrolle möglich ist. Das Mikromagnetische Verfahren ermöglicht bei neuen Anwendungsfällen eine Gütekontrolle der Nachbehandlung an Arbeitsproben ·und am Realbauteil. A measurement technique for inspection of material subsurface changes after mechanical surface treatment. The micro‐magnetic stress and material analysis has shown to be advantageous for characterizing the fatigue related material properties after high frequency post weld treatment. The quality control of standard parts treated by high frequency hammer peeing with the same peening parameters is possible by means of visual inspection. For new applications, the micro‐magnetic analysis provides a quality control of post weld treated work samples and real components.     

Reliable far-infrared photoconductivity method to identify a variety of residual donors in epitaxial GaAs

The chemical identity of unintentional contaminants in ultra-high purity eipitaxial GaAs and related semiconductor crystals can be distinguished by submillimeter wave magneto-spectroscopy at low temperature. An improved method of identifying hydrogen-like donors such as sulfur, silicon, selenium and germanium has been developed for the purpose of correcting some mistaken identifications that have been published during the past ten years. The new method requires the development of an experimental “signature curve” for each contaminant by measuring the energy of its 1s to 2p (m=?1) transition at several values of magnetic field intensity. The energy of this transition at a given magnetic field intensity is different depending upon the nucleus to which the electron is bound in the 1s state. The validity of the improved method was tested by means of transmutation doping.