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constants</title> <meta name="description" content="Search results for: cosmological constants"> <meta name="keywords" content="cosmological constants"> <meta name="viewport" content="width=device-width, initial-scale=1, minimum-scale=1, maximum-scale=1, user-scalable=no"> <meta charset="utf-8"> <link href="https://cdn.waset.org/favicon.ico" type="image/x-icon" rel="shortcut icon"> <link href="https://cdn.waset.org/static/plugins/bootstrap-4.2.1/css/bootstrap.min.css" rel="stylesheet"> <link href="https://cdn.waset.org/static/plugins/fontawesome/css/all.min.css" rel="stylesheet"> <link href="https://cdn.waset.org/static/css/site.css?v=150220211555" rel="stylesheet"> </head> <body> <header> <div class="container"> <nav class="navbar navbar-expand-lg navbar-light"> <a class="navbar-brand" href="https://waset.org"> <img src="https://cdn.waset.org/static/images/wasetc.png" alt="Open Science Research Excellence" title="Open Science Research Excellence" /> </a> <button class="d-block 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action="https://publications.waset.org/abstracts/search"> <div id="custom-search-input"> <div class="input-group"> <i class="fas fa-search"></i> <input type="text" class="search-query" name="q" placeholder="Author, Title, Abstract, Keywords" value="cosmological constants"> <input type="submit" class="btn_search" value="Search"> </div> </div> </form> </div> </div> <div class="row mt-3"> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Commenced</strong> in January 2007</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Frequency:</strong> Monthly</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Edition:</strong> International</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Paper Count:</strong> 267</div> </div> </div> </div> <h1 class="mt-3 mb-3 text-center" style="font-size:1.6rem;">Search results for: cosmological constants</h1> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">267</span> Bulk Viscous Bianchi Type V Cosmological Model with Time Dependent Gravitational Constant and Cosmological Constant in General Relativity</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Reena%20Behal">Reena Behal</a>, <a href="https://publications.waset.org/abstracts/search?q=D.%20P.%20Shukla"> D. P. Shukla</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this paper, we investigate Bulk Viscous Bianchi Type V Cosmological Model with Time dependent gravitational constant and cosmological constant in general Relativity by assuming ξ(t)=ξ_(0 ) p^m where ξ_(0 ) and m are constants. We also assume a variation law for Hubble parameter as H(R) = a (R^(-n)+1), where a>0, n>1 being constant. Two universe models were obtained, and their physical behavior has been discussed. When n=1 the Universe starts from singular state whereas when n=0 the cosmology follows a no singular state. The presence of bulk viscosity increase matter density’s value. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=Bulk%20Viscous%20Bianchi%20Type%20V%20Cosmological%20Model" title="Bulk Viscous Bianchi Type V Cosmological Model">Bulk Viscous Bianchi Type V Cosmological Model</a>, <a href="https://publications.waset.org/abstracts/search?q=hubble%20constants" title=" hubble constants"> hubble constants</a>, <a href="https://publications.waset.org/abstracts/search?q=gravitational%20constant" title=" gravitational constant"> gravitational constant</a>, <a href="https://publications.waset.org/abstracts/search?q=cosmological%20constants" title=" cosmological constants"> cosmological constants</a> </p> <a href="https://publications.waset.org/abstracts/78768/bulk-viscous-bianchi-type-v-cosmological-model-with-time-dependent-gravitational-constant-and-cosmological-constant-in-general-relativity" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/78768.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">174</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">266</span> On Bianchi Type Cosmological Models in Lyra’s Geometry</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=R.%20K.%20Dubey">R. K. Dubey</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Bianchi type cosmological models have been studied on the basis of Lyra’s geometry. Exact solution has been obtained by considering a time dependent displacement field for constant deceleration parameter and varying cosmological term of the universe. The physical behavior of the different models has been examined for different cases. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=Bianchi%20type-I%20cosmological%20model" title="Bianchi type-I cosmological model">Bianchi type-I cosmological model</a>, <a href="https://publications.waset.org/abstracts/search?q=variable%20gravitational%20coupling" title=" variable gravitational coupling"> variable gravitational coupling</a>, <a href="https://publications.waset.org/abstracts/search?q=cosmological%20constant%20term" title=" cosmological constant term"> cosmological constant term</a>, <a href="https://publications.waset.org/abstracts/search?q=Lyra%27s%20model" title=" Lyra's model"> Lyra's model</a> </p> <a href="https://publications.waset.org/abstracts/7581/on-bianchi-type-cosmological-models-in-lyras-geometry" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/7581.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">354</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">265</span> Bianchi Type- I Viscous Fluid Cosmological Models with Stiff Matter and Time Dependent Λ- Term</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Rajendra%20Kumar%20Dubey">Rajendra Kumar Dubey</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Einstein’s field equations with variable cosmological term Λ are considered in the presence of viscous fluid for Bianchi type I space time. Exact solutions of Einstein’s field equations are obtained by assuming cosmological term Λ Proportional to (R is a scale factor and m is constant). We observed that the shear viscosity is found to be responsible for faster removal of initial anisotropy in the universe. The physical significance of the cosmological models has also been discussed. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=bianchi%20type" title="bianchi type">bianchi type</a>, <a href="https://publications.waset.org/abstracts/search?q=I%20cosmological%20model" title=" I cosmological model"> I cosmological model</a>, <a href="https://publications.waset.org/abstracts/search?q=viscous%20fluid" title=" viscous fluid"> viscous fluid</a>, <a href="https://publications.waset.org/abstracts/search?q=cosmological%20constant%20%CE%9B" title=" cosmological constant Λ"> cosmological constant Λ</a> </p> <a href="https://publications.waset.org/abstracts/28301/bianchi-type-i-viscous-fluid-cosmological-models-with-stiff-matter-and-time-dependent-l-term" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/28301.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">528</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">264</span> Particle and Photon Trajectories near the Black Hole Immersed in the Nonstatic Cosmological Background</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Elena%20M.%20Kopteva">Elena M. Kopteva</a>, <a href="https://publications.waset.org/abstracts/search?q=Pavlina%20Jaluvkova"> Pavlina Jaluvkova</a>, <a href="https://publications.waset.org/abstracts/search?q=Zdenek%20Stuchlik"> Zdenek Stuchlik</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The question of constructing a consistent model of the cosmological black hole remains to be unsolved and still attracts the interest of cosmologists as far as it is important in a wide set of research problems including the problem of the black hole horizon dynamics, the problem of interplay between cosmological expansion and local gravity, the problem of structure formation in the early universe etc. In this work, the model of the cosmological black hole is built on the basis of the exact solution of the Einstein equations for the spherically symmetric inhomogeneous dust distribution in the approach of the mass function use. Possible trajectories for massive particles and photons near the black hole immersed in the nonstatic dust cosmological background are investigated in frame of the obtained model. The reference system of distant galaxy comoving to cosmological expansion combined with curvature coordinates is used, so that the resulting metric becomes nondiagonal and involves both proper ‘cosmological’ time and curvature spatial coordinates. For this metric the geodesic equations are analyzed for the test particles and photons, and the respective trajectories are built. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=exact%20solutions%20for%20Einstein%20equations" title="exact solutions for Einstein equations">exact solutions for Einstein equations</a>, <a href="https://publications.waset.org/abstracts/search?q=Lemaitre-Tolman-Bondi%20solution" title=" Lemaitre-Tolman-Bondi solution"> Lemaitre-Tolman-Bondi solution</a>, <a href="https://publications.waset.org/abstracts/search?q=cosmological%20black%20holes" title=" cosmological black holes"> cosmological black holes</a>, <a href="https://publications.waset.org/abstracts/search?q=particle%20and%20photon%20trajectories" title=" particle and photon trajectories"> particle and photon trajectories</a> </p> <a href="https://publications.waset.org/abstracts/63353/particle-and-photon-trajectories-near-the-black-hole-immersed-in-the-nonstatic-cosmological-background" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/63353.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">339</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">263</span> The Generalized Lemaitre-Tolman-Bondi Solutions in Modeling the Cosmological Black Holes </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Elena%20M.%20Kopteva">Elena M. Kopteva</a>, <a href="https://publications.waset.org/abstracts/search?q=Pavlina%20Jaluvkova"> Pavlina Jaluvkova</a>, <a href="https://publications.waset.org/abstracts/search?q=Zdenek%20Stuchlik"> Zdenek Stuchlik</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In spite of the numerous attempts to close the discussion about the influence of cosmological expansion on local gravitationally bounded systems, this question arises in literature again and again and remains still far from its final resolution. Here one of the main problems is the problem of obtaining a physically adequate model of strongly gravitating object immersed in non-static cosmological background. Such objects are usually called ‘cosmological’ black holes and are of great interest in wide set of cosmological and astrophysical areas. In this work the set of new exact solutions of the Einstein equations is derived for the flat space that generalizes the known Lemaitre-Tolman-Bondi solution for the case of nonzero pressure. The solutions obtained are pretending to describe the black hole immersed in nonstatic cosmological background and give a possibility to investigate the hot problems concerning the effects of the cosmological expansion in gravitationally bounded systems, the structure formation in the early universe, black hole thermodynamics and other related problems. It is shown that each of the solutions obtained contains either the Reissner-Nordstrom or the Schwarzschild black hole in the central region of the space. It is demonstrated that the approach of the mass function use in solving of the Einstein equations allows clear physical interpretation of the resulting solutions, that is of much benefit to any their concrete application. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=exact%20solutions%20of%20the%20Einstein%20equations" title="exact solutions of the Einstein equations">exact solutions of the Einstein equations</a>, <a href="https://publications.waset.org/abstracts/search?q=cosmological%20black%20holes" title=" cosmological black holes"> cosmological black holes</a>, <a href="https://publications.waset.org/abstracts/search?q=generalized%20Lemaitre-Tolman-Bondi%20solutions" title=" generalized Lemaitre-Tolman-Bondi solutions"> generalized Lemaitre-Tolman-Bondi solutions</a>, <a href="https://publications.waset.org/abstracts/search?q=nonzero%20pressure" title=" nonzero pressure"> nonzero pressure</a> </p> <a href="https://publications.waset.org/abstracts/63654/the-generalized-lemaitre-tolman-bondi-solutions-in-modeling-the-cosmological-black-holes" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/63654.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">423</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">262</span> Spectroscopic Constant Calculation of the BeF Molecule </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Nayla%20El-Kork">Nayla El-Kork</a>, <a href="https://publications.waset.org/abstracts/search?q=Farah%20Korjieh"> Farah Korjieh</a>, <a href="https://publications.waset.org/abstracts/search?q=Ahmed%20Bentiba"> Ahmed Bentiba</a>, <a href="https://publications.waset.org/abstracts/search?q=Mahmoud%20Korek"> Mahmoud Korek</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Ab-initio calculations have been performed to investigate the spectroscopic constants for the diatomic compound BeF. Values of the internuclear distance Re, the harmonic frequency ωe, the rotational constants Be, the electronic transition energy with respect to the ground state Te, the eignvalues Ev, the abscissas of the turning points Rmin, Rmax, the rotational constants Bv and the centrifugal distortion constants Dv have been calculated for the molecule’s ground and excited electronic states. Results are in agreement with experimental data. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=spectroscopic%20constant" title="spectroscopic constant">spectroscopic constant</a>, <a href="https://publications.waset.org/abstracts/search?q=potential%20energy%20curve" title=" potential energy curve"> potential energy curve</a>, <a href="https://publications.waset.org/abstracts/search?q=diatomic%20molecule" title=" diatomic molecule"> diatomic molecule</a>, <a href="https://publications.waset.org/abstracts/search?q=spectral%20analysis" title=" spectral analysis"> spectral analysis</a> </p> <a href="https://publications.waset.org/abstracts/28671/spectroscopic-constant-calculation-of-the-bef-molecule" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/28671.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">569</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">261</span> A Unified Fitting Method for the Set of Unified Constitutive Equations for Modelling Microstructure Evolution in Hot Deformation</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Chi%20Zhang">Chi Zhang</a>, <a href="https://publications.waset.org/abstracts/search?q=Jun%20Jiang"> Jun Jiang</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Constitutive equations are very important in finite element (FE) modeling, and the accuracy of the material constants in the equations have significant effects on the accuracy of the FE models. A wide range of constitutive equations are available; however, fitting the material constants in the constitutive equations could be complex and time-consuming due to the strong non-linearity and relationship between the constants. This work will focus on the development of a set of unified MATLAB programs for fitting the material constants in the constitutive equations efficiently. Users will only need to supply experimental data in the required format and run the program without modifying functions or precisely guessing the initial values, or finding the parameters in previous works and will be able to fit the material constants efficiently. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=constitutive%20equations" title="constitutive equations">constitutive equations</a>, <a href="https://publications.waset.org/abstracts/search?q=FE%20modelling" title=" FE modelling"> FE modelling</a>, <a href="https://publications.waset.org/abstracts/search?q=MATLAB%20program" title=" MATLAB program"> MATLAB program</a>, <a href="https://publications.waset.org/abstracts/search?q=non-linear%20curve%20fitting" title=" non-linear curve fitting"> non-linear curve fitting</a> </p> <a href="https://publications.waset.org/abstracts/162562/a-unified-fitting-method-for-the-set-of-unified-constitutive-equations-for-modelling-microstructure-evolution-in-hot-deformation" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/162562.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">99</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">260</span> Classification of Cosmological Wormhole Solutions in the Framework of General Relativity</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Usamah%20Al-Ali">Usamah Al-Ali</a> </p> <p class="card-text"><strong>Abstract:</strong></p> We explore the effect of expanding space on the exoticity of the matter supporting a traversable Lorentzian wormhole of zero radial tide whose line element is given by ds2 = dt^2 − a^2(t)[ dr^2/(1 − kr2 −b(r)/r)+ r2dΩ^2 in the context of General Relativity. This task is achieved by deriving the Einstein field equations for anisotropic matter field corresponding to the considered cosmological wormhole metric and performing a classification of their solutions on the basis of a variable equations of state (EoS) of the form p = ω(r)ρ. Explicit forms of the shape function b(r) and the scale factor a(t) arising in the classification are utilized to construct the corresponding energy-momentum tensor where the energy conditions for each case is investigated. While the violation of energy conditions is inevitable in case of static wormholes, the classification we performed leads to interesting solutions in which this violation is either reduced or eliminated. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=general%20relativity" title="general relativity">general relativity</a>, <a href="https://publications.waset.org/abstracts/search?q=Einstein%20field%20equations" title=" Einstein field equations"> Einstein field equations</a>, <a href="https://publications.waset.org/abstracts/search?q=energy%20conditions" title=" energy conditions"> energy conditions</a>, <a href="https://publications.waset.org/abstracts/search?q=cosmological%20wormhole" title=" cosmological wormhole"> cosmological wormhole</a> </p> <a href="https://publications.waset.org/abstracts/150239/classification-of-cosmological-wormhole-solutions-in-the-framework-of-general-relativity" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/150239.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">63</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">259</span> Elastic Constants of Fir Wood Using Ultrasound and Compression Tests</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ergun%20Guntekin">Ergun Guntekin</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Elastic constants of Fir wood (Abies cilicica) have been investigated by means of ultrasound and compression tests. Three modulus of elasticity in principal directions (EL, ER, ET), six Poisson’s ratios (ʋLR, ʋLT, ʋRT, ʋTR, ʋRL, ʋTL) and three shear modules (GLR, GRT, GLT) were determined. 20 x 20 x 60 mm samples were conditioned at 65 % relative humidity and 20ºC before testing. Three longitudinal and six shear wave velocities propagating along the principal axes of anisotropy, and additionally, three quasi-shear wave velocities at 45° angle with respect to the principal axes of anisotropy were measured. 2.27 MHz longitudinal and 1 MHz shear sensors were used for obtaining sound velocities. Stress-strain curves of the samples in compression tests were obtained using bi-axial extensometer in order to calculate elastic constants. Test results indicated that most of the elastic constants determined in the study are within the acceptable range. Although elastic constants determined from ultrasound are usually higher than those determined from compression tests, the values of EL and GLR determined from compression tests were higher in the study. The results of this study can be used in the numerical modeling of elements or systems under load using Fir wood. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=compression%20tests" title="compression tests">compression tests</a>, <a href="https://publications.waset.org/abstracts/search?q=elastic%20constants" title=" elastic constants"> elastic constants</a>, <a href="https://publications.waset.org/abstracts/search?q=fir%20wood" title=" fir wood"> fir wood</a>, <a href="https://publications.waset.org/abstracts/search?q=ultrasound" title=" ultrasound"> ultrasound</a> </p> <a href="https://publications.waset.org/abstracts/92992/elastic-constants-of-fir-wood-using-ultrasound-and-compression-tests" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/92992.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">217</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">258</span> Theoretical Prediction of the Structural, Elastic, Electronic, Optical, and Thermal Properties of Cubic Perovskites CsXF3 (X = Ca, Sr, and Hg) under Pressure Effect</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=M.%20A.%20Ghebouli">M. A. Ghebouli</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Bouhemadou"> A. Bouhemadou</a>, <a href="https://publications.waset.org/abstracts/search?q=H.%20Choutri"> H. Choutri</a>, <a href="https://publications.waset.org/abstracts/search?q=L.%20Louaila"> L. Louaila </a> </p> <p class="card-text"><strong>Abstract:</strong></p> Some physical properties of the cubic perovskites CsXF3 (X = Sr, Ca, and Hg) have been investigated using pseudopotential plane–wave (PP-PW) method based on the density functional theory (DFT). The calculated lattice constants within GGA (PBE) and LDA (CA-PZ) agree reasonably with the available experiment data. The elastic constants and their pressure derivatives are predicted using the static finite strain technique. We derived the bulk and shear moduli, Young’s modulus, Poisson’s ratio and Lamé’s constants for ideal polycrystalline aggregates. The analysis of B/G ratio indicates that CsXF3 (X = Ca, Sr, and Hg) are ductile materials. The thermal effect on the volume, bulk modulus, heat capacities CV, CP, and Debye temperature was predicted. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=perovskite" title="perovskite">perovskite</a>, <a href="https://publications.waset.org/abstracts/search?q=PP-PW%20method" title=" PP-PW method"> PP-PW method</a>, <a href="https://publications.waset.org/abstracts/search?q=elastic%20constants" title=" elastic constants"> elastic constants</a>, <a href="https://publications.waset.org/abstracts/search?q=electronic%20band%20structure" title=" electronic band structure "> electronic band structure </a> </p> <a href="https://publications.waset.org/abstracts/1794/theoretical-prediction-of-the-structural-elastic-electronic-optical-and-thermal-properties-of-cubic-perovskites-csxf3-x-ca-sr-and-hg-under-pressure-effect" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/1794.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">437</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">257</span> The Evolution of the Simulated and Observed Star Formation Rates of Galaxies for the Past 13 Billion Years</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Antonios%20Katsianis">Antonios Katsianis</a> </p> <p class="card-text"><strong>Abstract:</strong></p> I present the evolution of the galaxy Star Formation Rate Function (SFRF), star formation rate-stellar mass relation (SFR-M*) and Cosmic Star Formation Rate Density (CSFRD) of z = 0-8 galaxies employing both the Evolution and Assembly of GaLaxies and their Environments (EAGLE) simulations and a compilation of UV, Ha, radio and IR data. While I present comparisons between the above, I evaluate the effect and importance of supernovae/active galactic nuclei feedback. The relation between the star formation rate and stellar mass of galaxies represents a fundamental constraint on galaxy formation, and has been studied extensively both in observations and cosmological hydrodynamic simulations. However, a tension between the above is reported in the literature. I present the evolution of the SFR-M* relation and demonstrate the inconsistencies between observations that are retrieved using different methods. I employ cosmological hydrodynamic simulations combined with radiative transfer methods and compare these with a range of observed data in order to investigate further the root of this tension. Last, I present insights about the scatter of the SFR-M* relation and investigate which mechanisms (e.g. feedback) drive its shape and evolution. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=cosmological%20simulations" title="cosmological simulations">cosmological simulations</a>, <a href="https://publications.waset.org/abstracts/search?q=galaxy%20formation%20and%20evolution" title=" galaxy formation and evolution"> galaxy formation and evolution</a>, <a href="https://publications.waset.org/abstracts/search?q=star%20formation%20rate" title=" star formation rate"> star formation rate</a>, <a href="https://publications.waset.org/abstracts/search?q=stellar%20masses" title=" stellar masses"> stellar masses</a> </p> <a href="https://publications.waset.org/abstracts/118594/the-evolution-of-the-simulated-and-observed-star-formation-rates-of-galaxies-for-the-past-13-billion-years" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/118594.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">148</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">256</span> Obtaining Constants of Johnson-Cook Material Model Using a Combined Experimental, Numerical Simulation and Optimization Method</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=F.%20Rahimi%20Dehgolan">F. Rahimi Dehgolan</a>, <a href="https://publications.waset.org/abstracts/search?q=M.%20Behzadi"> M. Behzadi</a>, <a href="https://publications.waset.org/abstracts/search?q=J.%20Fathi%20Sola"> J. Fathi Sola</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this article, the Johnson-Cook material model’s constants for structural steel ST.37 have been determined by a method which integrates experimental tests, numerical simulation, and optimization. In the first step, a quasi-static test was carried out on a plain specimen. Next, the constants were calculated for it by minimizing the difference between the results acquired from the experiment and numerical simulation. Then, a quasi-static tension test was performed on three notched specimens with different notch radii. At last, in order to verify the results, they were used in numerical simulation of notched specimens and it was observed that experimental and simulation results are in good agreement. Changing the diameter size of the plain specimen in the necking area was set as the objective function in the optimization step. For final validation of the proposed method, diameter variation was considered as a parameter and its sensitivity to a change in any of the model constants was examined and the results were completely corroborating. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=constants" title="constants">constants</a>, <a href="https://publications.waset.org/abstracts/search?q=Johnson-Cook%20material%20model" title=" Johnson-Cook material model"> Johnson-Cook material model</a>, <a href="https://publications.waset.org/abstracts/search?q=notched%20specimens" title=" notched specimens"> notched specimens</a>, <a href="https://publications.waset.org/abstracts/search?q=quasi-static%20test" title=" quasi-static test"> quasi-static test</a>, <a href="https://publications.waset.org/abstracts/search?q=sensitivity" title=" sensitivity"> sensitivity</a> </p> <a href="https://publications.waset.org/abstracts/49772/obtaining-constants-of-johnson-cook-material-model-using-a-combined-experimental-numerical-simulation-and-optimization-method" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/49772.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">311</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">255</span> Dark Gravity Confronted with Supernovae, Baryonic Oscillations and Cosmic Microwave Background Data</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Frederic%20Henry-Couannier">Frederic Henry-Couannier</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Dark Gravity is a natural extension of general relativity in presence of a flat non dynamical background. Matter and radiation fields from its dark sector, as soon as their gravity dominates over our side fields gravity, produce a constant acceleration law of the scale factor. After a brief reminder of the Dark Gravity theory foundations, the confrontation with the main cosmological probes is carried out. We show that, amazingly, the sudden transition between the usual matter dominated decelerated expansion law a(t) ∝ t²/³ and this accelerated expansion law a(t) ∝ t² predicted by the theory should be able to fit the main cosmological probes (SN, BAO, CMB and age of the oldest stars data) but also direct H₀ measurements with two free parameters only: H₀ and the transition redshift. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=anti-gravity" title="anti-gravity">anti-gravity</a>, <a href="https://publications.waset.org/abstracts/search?q=negative%20energies" title=" negative energies"> negative energies</a>, <a href="https://publications.waset.org/abstracts/search?q=time%20reversal" title=" time reversal"> time reversal</a>, <a href="https://publications.waset.org/abstracts/search?q=field%20discontinuities" title=" field discontinuities"> field discontinuities</a>, <a href="https://publications.waset.org/abstracts/search?q=dark%20energy%20theory" title=" dark energy theory"> dark energy theory</a> </p> <a href="https://publications.waset.org/abstracts/185998/dark-gravity-confronted-with-supernovae-baryonic-oscillations-and-cosmic-microwave-background-data" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/185998.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">55</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">254</span> Covariance and Quantum Cosmology: A Comparison of Two Matter Clocks</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Theodore%20Halnon">Theodore Halnon</a>, <a href="https://publications.waset.org/abstracts/search?q=Martin%20Bojowald"> Martin Bojowald</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In relativity, time is relative between reference frames. However, quantum mechanics requires a specific time coordinate in order to write an evolution equation for wave functions. This difference between the two theories leads to the problem of time in quantum gravity. One method to study quantum relativity is to interpret the dynamics of a matter field as a clock. In order to test the relationship between different reference frames, an isotropic cosmological model with two matter ingredients is introduced. One is given by a scalar field and one by vacuum energy or a cosmological constant. There are two matter fields, and thus two different Hamiltonians are derived from the respective clock rates. Semi-classical solutions are found for these equations and a comparison is made of the physical predictions that they imply. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=cosmology" title="cosmology">cosmology</a>, <a href="https://publications.waset.org/abstracts/search?q=deparameterization" title=" deparameterization"> deparameterization</a>, <a href="https://publications.waset.org/abstracts/search?q=general%20relativity" title=" general relativity"> general relativity</a>, <a href="https://publications.waset.org/abstracts/search?q=quantum%20mechanics" title=" quantum mechanics"> quantum mechanics</a> </p> <a href="https://publications.waset.org/abstracts/55135/covariance-and-quantum-cosmology-a-comparison-of-two-matter-clocks" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/55135.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">308</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">253</span> Determination of Elastic Constants for Scots Pine Grown in Turkey Using Ultrasound</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ergun%20Guntekin">Ergun Guntekin</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This study investigated elastic constants of scots pine (Pinus sylvestris L.) grown in Turkey by means of ultrasonic waves. Three Young’s modulus, three shear modulus and six Poisson ratios were determined at constant moisture content (12 %). Three longitudinal and six shear wave velocities propagating along the principal axes of anisotropy, and additionally, three quasi-shear wave velocities at 45° with respect to the principal axes of anisotropy were measured using EPOCH 650 ultrasonic flaw detector. The measured average longitudinal wave velocities for the sapwood in L, R, T directions were 4795, 1713 and 1117 m/s, respectively. The measured average shear wave velocities ranged from 682 to 1382 m/s. The measured quasi-shear wave velocities varied between 642 and 1280 m/s. The calculated average modulus of elasticity values for the sapwood in L, R, T directions were 11913, 1565 and 663 N/mm2, respectively. The calculated shear modulus in LR, LT and RT planes were 1031, 541, 415 N/mm2. Comparing with available literature, the predicted elastic constants are acceptable. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=elastic%20constants" title="elastic constants">elastic constants</a>, <a href="https://publications.waset.org/abstracts/search?q=prediction" title=" prediction"> prediction</a>, <a href="https://publications.waset.org/abstracts/search?q=Scots%20pine" title=" Scots pine"> Scots pine</a>, <a href="https://publications.waset.org/abstracts/search?q=ultrasound" title=" ultrasound"> ultrasound</a> </p> <a href="https://publications.waset.org/abstracts/50083/determination-of-elastic-constants-for-scots-pine-grown-in-turkey-using-ultrasound" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/50083.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">279</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">252</span> Optimizing the Efficiency of Measuring Instruments in Ouagadougou-Burkina Faso</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Moses%20Emetere">Moses Emetere</a>, <a href="https://publications.waset.org/abstracts/search?q=Marvel%20Akinyemi"> Marvel Akinyemi</a>, <a href="https://publications.waset.org/abstracts/search?q=S.%20E.%20Sanni"> S. E. Sanni</a> </p> <p class="card-text"><strong>Abstract:</strong></p> At the moment, AERONET or AMMA database shows a large volume of data loss. With only about 47% data set available to the scientist, it is evident that accurate nowcast or forecast cannot be guaranteed. The calibration constants of most radiosonde or weather stations are not compatible with the atmospheric conditions of the West African climate. A dispersion model was developed to incorporate salient mathematical representations like a Unified number. The Unified number was derived to describe the turbulence of the aerosols transport in the frictional layer of the lower atmosphere. Fourteen years data set from Multi-angle Imaging SpectroRadiometer (MISR) was tested using the dispersion model. A yearly estimation of the atmospheric constants over Ouagadougou using the model was obtained with about 87.5% accuracy. It further revealed that the average atmospheric constant for Ouagadougou-Niger is a_1 = 0.626, a_2 = 0.7999 and the tuning constants is n_1 = 0.09835 and n_2 = 0.266. Also, the yearly atmospheric constants affirmed the lower atmosphere of Ouagadougou is very dynamic. Hence, it is recommended that radiosonde and weather station manufacturers should constantly review the atmospheric constant over a geographical location to enable about eighty percent data retrieval. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=aerosols%20retention" title="aerosols retention">aerosols retention</a>, <a href="https://publications.waset.org/abstracts/search?q=aerosols%20loading" title=" aerosols loading"> aerosols loading</a>, <a href="https://publications.waset.org/abstracts/search?q=statistics" title=" statistics"> statistics</a>, <a href="https://publications.waset.org/abstracts/search?q=analytical%20technique" title=" analytical technique"> analytical technique</a> </p> <a href="https://publications.waset.org/abstracts/55320/optimizing-the-efficiency-of-measuring-instruments-in-ouagadougou-burkina-faso" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/55320.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">315</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">251</span> Calculation of Lattice Constants and Band Gaps for Generalized Quasicrystals of InGaN Alloy: A First Principle Study</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Rohin%20Sharma">Rohin Sharma</a>, <a href="https://publications.waset.org/abstracts/search?q=Sumantu%20Chaulagain"> Sumantu Chaulagain</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper presents calculations of total energy of InGaN alloy carried out in a disordered quasirandom structure for a triclinic super cell. This structure replicates the disorder and composition effect in the alloy. First principle calculations within the density functional theory with the local density approximation approach is employed to accurately determine total energy of the system. Lattice constants and band gaps associated with the ground states are then estimated for different concentration ratios of the alloy. We provide precise results of quasirandom structures of the alloy and their lattice constants with the total energy and band gap energy of the system for the range of seven different composition ratios and their respective lattice parameters. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=DFT" title="DFT">DFT</a>, <a href="https://publications.waset.org/abstracts/search?q=ground%20state" title=" ground state"> ground state</a>, <a href="https://publications.waset.org/abstracts/search?q=LDA" title=" LDA"> LDA</a>, <a href="https://publications.waset.org/abstracts/search?q=quasicrystal" title=" quasicrystal"> quasicrystal</a>, <a href="https://publications.waset.org/abstracts/search?q=triclinic%20super%20cell" title=" triclinic super cell"> triclinic super cell</a> </p> <a href="https://publications.waset.org/abstracts/81138/calculation-of-lattice-constants-and-band-gaps-for-generalized-quasicrystals-of-ingan-alloy-a-first-principle-study" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/81138.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">188</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">250</span> Optical and Dielectric Properties of Self-Assembled 0D Hybrid Organic-Inorganic Insulator</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=S.%20Kassou">S. Kassou</a>, <a href="https://publications.waset.org/abstracts/search?q=R.%20El%20Mrabet"> R. El Mrabet</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Belaaraj"> A. Belaaraj</a>, <a href="https://publications.waset.org/abstracts/search?q=P.%20Guionneau"> P. Guionneau</a>, <a href="https://publications.waset.org/abstracts/search?q=N.%20Hadi"> N. Hadi</a>, <a href="https://publications.waset.org/abstracts/search?q=T.%20Lamcharfi"> T. Lamcharfi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The organic–inorganic hybrid perovskite-like [C<sub>6</sub>H<sub>5</sub>C<sub>2</sub>H<sub>4</sub>NH<sub>3</sub>]<sub>2</sub>ZnCl<sub>4</sub> (PEA-ZnCl<sub>4</sub>) was synthesized by saturated solutions method. X-ray powder diffraction, Raman spectroscopy, UV-visible transmittance, and capacitance meter measurements have been used to characterize the structure, the functional groups, the optical parameters, and the dielectric constants of the material. The material has a layered structure. The optical transmittance (T %) was recorded and applied to deduce the absorption coefficient (α) and optical band gap (Eg). The hybrid shows an insulator character with a direct band gap about 4.46 eV, and presents high dielectric constants up to a frequency of about 10<sup>5</sup> Hz, which suggests a ferroelectric behavior. The reported optical and dielectric properties can help to understand the fundamental properties of perovskite materials and also to be used for optimizing or designing new devices. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=dielectric%20constants" title="dielectric constants">dielectric constants</a>, <a href="https://publications.waset.org/abstracts/search?q=optical%20band%20gap%20%28eg%29" title=" optical band gap (eg)"> optical band gap (eg)</a>, <a href="https://publications.waset.org/abstracts/search?q=optical%20parameters" title=" optical parameters"> optical parameters</a>, <a href="https://publications.waset.org/abstracts/search?q=Raman%20spectroscopy" title=" Raman spectroscopy"> Raman spectroscopy</a>, <a href="https://publications.waset.org/abstracts/search?q=self-assembly%20organic%20inorganic%20hybrid" title=" self-assembly organic inorganic hybrid"> self-assembly organic inorganic hybrid</a> </p> <a href="https://publications.waset.org/abstracts/65237/optical-and-dielectric-properties-of-self-assembled-0d-hybrid-organic-inorganic-insulator" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/65237.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">402</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">249</span> First Principal Calculation of Structural, Elastic and Thermodynamic Properties of Yttrium-Copper Intermetallic Compound</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ammar%20Benamrani">Ammar Benamrani</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This work investigates the equation of state parameters, elastic constants, and several other physical properties of (B2-type) Yttrium-Copper (YCu) rare earth intermetallic compound using the projected augmented wave (PAW) pseudopotentials method as implemented in the Quantum Espresso code. Using both the local density approximation (LDA) and the generalized gradient approximation (GGA), the finding of this research on the lattice parameter of YCu intermetallic compound agree very well with the experimental ones. The obtained results of the elastic constants and the Debye temperature are also in general in good agreement compared to the theoretical ones reported previously in literature. Furthermore, several thermodynamic properties of YCu intermetallic compound have been studied using quasi-harmonic approximations (QHA). The calculated data on the thermodynamic properties shows that the free energy and both isothermal and adiabatic bulk moduli decrease gradually with increasing of the temperature, while all other thermodynamic quantities increase with the temperature. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=Yttrium-Copper%20intermetallic%20compound" title="Yttrium-Copper intermetallic compound">Yttrium-Copper intermetallic compound</a>, <a href="https://publications.waset.org/abstracts/search?q=thermo_pw%20package" title=" thermo_pw package"> thermo_pw package</a>, <a href="https://publications.waset.org/abstracts/search?q=elastic%20constants" title=" elastic constants"> elastic constants</a>, <a href="https://publications.waset.org/abstracts/search?q=thermodynamic%20properties" title=" thermodynamic properties"> thermodynamic properties</a> </p> <a href="https://publications.waset.org/abstracts/132557/first-principal-calculation-of-structural-elastic-and-thermodynamic-properties-of-yttrium-copper-intermetallic-compound" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/132557.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">149</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">248</span> Effects of Heat Treatment on the Elastic Constants of Cedar Wood</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Tugba%20Yilmaz%20Aydin">Tugba Yilmaz Aydin</a>, <a href="https://publications.waset.org/abstracts/search?q=Ergun%20Guntekin"> Ergun Guntekin</a>, <a href="https://publications.waset.org/abstracts/search?q=Murat%20Aydin"> Murat Aydin</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Effects of heat treatment on the elastic constants of cedar wood (Cedrus libani) were investigated. Specimens were exposed to heat under atmospheric pressure at four different temperatures (120, 150, 180, 210 °C) and three different time levels (2, 5, 8 hours). Three Young’s modulus (EL, ER, ET) and six Poisson ratios (μLR, μLT, μRL, μRT, μTL, μTR) were determined from compression test using bi-axial extensometer at constant moisture content (12 %). Three shear modulus were determined using ultrasound. Six shear wave velocities propagating along the principal axes of anisotropy were measured using EPOCH 650 ultrasonic flaw detector with 1 MHz transverse transducers. The properties of the samples tested were significantly affected by heat treatment by different degree. As a result, softer treatments yielded some amount of increase in Young modulus and shear modulus values, but increase of time and temperature resulted in significant decrease for both values. Poisson ratios seemed insensitive to heat treatment. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=cedar%20wood" title="cedar wood">cedar wood</a>, <a href="https://publications.waset.org/abstracts/search?q=elastic%20constants" title=" elastic constants"> elastic constants</a>, <a href="https://publications.waset.org/abstracts/search?q=heat%20treatment" title=" heat treatment"> heat treatment</a>, <a href="https://publications.waset.org/abstracts/search?q=ultrasound" title=" ultrasound"> ultrasound</a> </p> <a href="https://publications.waset.org/abstracts/50445/effects-of-heat-treatment-on-the-elastic-constants-of-cedar-wood" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/50445.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">384</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">247</span> On the Dwindling Supply of the Observable Cosmic Microwave Background Radiation</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Jia-Chao%20Wang">Jia-Chao Wang</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The cosmic microwave background radiation (CMB) freed during the recombination era can be considered as a photon source of small duration; a one-time event happened everywhere in the universe simultaneously. If space is divided into concentric shells centered at an observer’s location, one can imagine that the CMB photons originated from the nearby shells would reach and pass the observer first, and those in shells farther away would follow as time goes forward. In the Big Bang model, space expands rapidly in a time-dependent manner as described by the scale factor. This expansion results in an event horizon coincident with one of the shells, and its radius can be calculated using cosmological calculators available online. Using Planck 2015 results, its value during the recombination era at cosmological time t = 0.379 million years (My) is calculated to be Revent = 56.95 million light-years (Mly). The event horizon sets a boundary beyond which the freed CMB photons will never reach the observer. The photons within the event horizon also exhibit a peculiar behavior. Calculated results show that the CMB observed today was freed in a shell located at 41.8 Mly away (inside the boundary set by Revent) at t = 0.379 My. These photons traveled 13.8 billion years (Gy) to reach here. Similarly, the CMB reaching the observer at t = 1, 5, 10, 20, 40, 60, 80, 100 and 120 Gy are calculated to be originated at shells of R = 16.98, 29.96, 37.79, 46.47, 53.66, 55.91, 56.62, 56.85 and 56.92 Mly, respectively. The results show that as time goes by, the R value approaches Revent = 56.95 Mly but never exceeds it, consistent with the earlier statement that beyond Revent the freed CMB photons will never reach the observer. The difference Revert - R can be used as a measure of the remaining observable CMB photons. Its value becomes smaller and smaller as R approaching Revent, indicating a dwindling supply of the observable CMB radiation. In this paper, detailed dwindling effects near the event horizon are analyzed with the help of online cosmological calculators based on the lambda cold dark matter (ΛCDM) model. It is demonstrated in the literature that assuming the CMB to be a blackbody at recombination (about 3000 K), then it will remain so over time under cosmological redshift and homogeneous expansion of space, but with the temperature lowered (2.725 K now). The present result suggests that the observable CMB photon density, besides changing with space expansion, can also be affected by the dwindling supply associated with the event horizon. This raises the question of whether the blackbody of CMB at recombination can remain so over time. Being able to explain the blackbody nature of the observed CMB is an import part of the success of the Big Bang model. The present results cast some doubts on that and suggest that the model may have an additional challenge to deal with. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=blackbody%20of%20CMB" title="blackbody of CMB">blackbody of CMB</a>, <a href="https://publications.waset.org/abstracts/search?q=CMB%20radiation" title=" CMB radiation"> CMB radiation</a>, <a href="https://publications.waset.org/abstracts/search?q=dwindling%20supply%20of%20CMB" title=" dwindling supply of CMB"> dwindling supply of CMB</a>, <a href="https://publications.waset.org/abstracts/search?q=event%20horizon" title=" event horizon"> event horizon</a> </p> <a href="https://publications.waset.org/abstracts/116653/on-the-dwindling-supply-of-the-observable-cosmic-microwave-background-radiation" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/116653.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">119</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">246</span> Ab Initio Calculation of Fundamental Properties of CaxMg1-xA (a = Se and Te) Alloys in the Rock-Salt Structure</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=M.%20A.%20Ghebouli">M. A. Ghebouli</a>, <a href="https://publications.waset.org/abstracts/search?q=H.%20Choutri"> H. Choutri</a>, <a href="https://publications.waset.org/abstracts/search?q=B.%20Ghebouli"> B. Ghebouli </a>, <a href="https://publications.waset.org/abstracts/search?q=M.%20Fatmi"> M. Fatmi</a>, <a href="https://publications.waset.org/abstracts/search?q=L.%20Louail"> L. Louail</a> </p> <p class="card-text"><strong>Abstract:</strong></p> We employed the density-functional perturbation theory (DFPT) within the generalized gradient approximation (GGA), the local density approximation (LDA) and the virtual-crystal approximation (VCA) to study the effect of composition on the structure, stability, energy gaps, electron effective mass, the dynamic effective charge, optical and acoustical phonon frequencies and static and high dielectric constants of the rock-salt CaxMg1-xSe and CaxMg1-xTe alloys. The computed equilibrium lattice constant and bulk modulus show an important deviation from the linear concentration. From the Voigt-Reuss-Hill approximation, CaxMg1-xSe and CaxMg1-xTe present lower stiffness and lateral expansion. For Ca content ranging between 0.25-0.75, the elastic constants, energy gaps, electron effective mass and dynamic effective charge are predictions. The elastic constants and computed phonon dispersion curves indicate that these alloys are mechanically stable. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=CaxMg1-xSe" title="CaxMg1-xSe">CaxMg1-xSe</a>, <a href="https://publications.waset.org/abstracts/search?q=CaxMg1-xTe" title=" CaxMg1-xTe"> CaxMg1-xTe</a>, <a href="https://publications.waset.org/abstracts/search?q=band%20structure" title=" band structure"> band structure</a>, <a href="https://publications.waset.org/abstracts/search?q=phonon" title=" phonon"> phonon</a> </p> <a href="https://publications.waset.org/abstracts/13861/ab-initio-calculation-of-fundamental-properties-of-caxmg1-xa-a-se-and-te-alloys-in-the-rock-salt-structure" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/13861.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">540</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">245</span> Determination of Elasticity Constants of Isotropic Thin Films Using Impulse Excitation Technique</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=M.%20F.%20Slim">M. F. Slim</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Alhussein"> A. Alhussein</a>, <a href="https://publications.waset.org/abstracts/search?q=F.%20Sanchette"> F. Sanchette</a>, <a href="https://publications.waset.org/abstracts/search?q=M.%20Fran%C3%A7ois"> M. François</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Thin films are widely used in various applications to enhance the surface properties and characteristics of materials. They are used in many domains such as: biomedical, automotive, aeronautics, military, electronics and energy. Depending on the elaboration technique, the elastic behavior of thin films may be different from this of bulk materials. This dependence on the elaboration techniques and their parameters makes the control of the elasticity constants of coated components necessary. Our work is focused on the characterization of the elasticity constants of isotropic thin films by means of Impulse Excitation Techniques. The tests rely on the measurement of the sample resonance frequency before and after deposition. In this work, a finite element model was performed with ABAQUS software. This model was then compared with the analytical approaches used to determine the Young’s and shear moduli. The best model to determine the film Young’s modulus was identified and a relation allowing the determination of the shear modulus of thin films of any thickness was developed. In order to confirm the model experimentally, Tungsten films were deposited on glass substrates by DC magnetron sputtering of a 99.99% purity tungsten target. The choice of tungsten was done because it is well known that its elastic behavior at crystal scale is ideally isotropic. The macroscopic elasticity constants, Young’s and shear moduli and Poisson’s ratio of the deposited film were determined by means of Impulse Excitation Technique. The Young’s modulus obtained from IET was compared with measurements by the nano-indentation technique. We did not observe any significant difference and the value is in accordance with the one reported in the literature. This work presents a new methodology on the determination of the elasticity constants of thin films using Impulse Excitation Technique. A formulation allowing the determination of the shear modulus of a coating, whatever the thickness, was developed and used to determine the macroscopic elasticity constants of tungsten films. The developed model was validated numerically and experimentally. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=characterization" title="characterization">characterization</a>, <a href="https://publications.waset.org/abstracts/search?q=coating" title=" coating"> coating</a>, <a href="https://publications.waset.org/abstracts/search?q=dynamical%20resonant%20method" title=" dynamical resonant method"> dynamical resonant method</a>, <a href="https://publications.waset.org/abstracts/search?q=Poisson%27s%20ratio" title=" Poisson's ratio"> Poisson's ratio</a>, <a href="https://publications.waset.org/abstracts/search?q=PVD" title=" PVD"> PVD</a>, <a href="https://publications.waset.org/abstracts/search?q=shear%20modulus" title=" shear modulus"> shear modulus</a>, <a href="https://publications.waset.org/abstracts/search?q=Young%27s%20modulus" title=" Young's modulus"> Young's modulus</a> </p> <a href="https://publications.waset.org/abstracts/61317/determination-of-elasticity-constants-of-isotropic-thin-films-using-impulse-excitation-technique" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/61317.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">363</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">244</span> Determination of Optical Constants of Semiconductor Thin Films by Ellipsometry</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=A%C3%AFssa%20Manallah">Aïssa Manallah</a>, <a href="https://publications.waset.org/abstracts/search?q=Mohamed%20Bouafia"> Mohamed Bouafia</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Ellipsometry is an optical method based on the study of the behavior of polarized light. The light reflected on a surface induces a change in the polarization state which depends on the characteristics of the material (complex refractive index and thickness of the different layers constituting the device). The purpose of this work is to determine the optical properties of semiconductor thin films by ellipsometry. This paper describes the experimental aspects concerning the semiconductor samples, the SE400 ellipsometer principle, and the results obtained by direct measurements of ellipsometric parameters and modelling using appropriate software. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=ellipsometry" title="ellipsometry">ellipsometry</a>, <a href="https://publications.waset.org/abstracts/search?q=optical%20constants" title=" optical constants"> optical constants</a>, <a href="https://publications.waset.org/abstracts/search?q=semiconductors" title=" semiconductors"> semiconductors</a>, <a href="https://publications.waset.org/abstracts/search?q=thin%20films" title=" thin films"> thin films</a> </p> <a href="https://publications.waset.org/abstracts/53464/determination-of-optical-constants-of-semiconductor-thin-films-by-ellipsometry" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/53464.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">307</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">243</span> Teaching and Learning Dialectical Relationship between Thermodynamic Equilibrium and Reaction Rate Constant</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Mohammad%20Anwar">Mohammad Anwar</a>, <a href="https://publications.waset.org/abstracts/search?q=Shah%20Waliullah"> Shah Waliullah</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The development of science and technology in the present era has an urgent demand for the training of thinking of undergraduates. This requirement actively promotes research and teaching of basic theories, beneficial to the career development of students. This study clarified the dialectical relation between the thermodynamic equilibrium constant and reaction rate constant through the contrast thinking method. Findings reveal that both the isobaric Van't Hoff equation and the Arrhenius equation had four similar forms, and the change in the trend of both constants showed a similar law. By the derivation of the formation rate constant of the product (KY) and the consumption rate constant of the reactant (KA), the ratio of both constants at the end state indicated the nature of the equilibrium state in agreement with that of the thermodynamic equilibrium constant (K^θ (T)). This study has thus presented that the thermodynamic equilibrium constant contained the characteristics of microscopic dynamics based on the analysis of the reaction mechanism, and both constants are organically connected and unified. The reaction enthalpy and activation energy are closely related to each other with the same connotation. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=thermodynamic%20equilibrium%20constant" title="thermodynamic equilibrium constant">thermodynamic equilibrium constant</a>, <a href="https://publications.waset.org/abstracts/search?q=reaction%20rate%20constant" title=" reaction rate constant"> reaction rate constant</a>, <a href="https://publications.waset.org/abstracts/search?q=PBL%20teaching" title=" PBL teaching"> PBL teaching</a>, <a href="https://publications.waset.org/abstracts/search?q=dialectical%20relation" title=" dialectical relation"> dialectical relation</a>, <a href="https://publications.waset.org/abstracts/search?q=innovative%20thinking" title=" innovative thinking"> innovative thinking</a> </p> <a href="https://publications.waset.org/abstracts/161693/teaching-and-learning-dialectical-relationship-between-thermodynamic-equilibrium-and-reaction-rate-constant" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/161693.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">109</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">242</span> The Effect of Aluminum Oxide Nanoparticles on the Optical Properties of (PVP-PEG) Blend</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Hussein%20Hakim">Hussein Hakim</a>, <a href="https://publications.waset.org/abstracts/search?q=Zainab%20Al-Ramadhan"> Zainab Al-Ramadhan</a>, <a href="https://publications.waset.org/abstracts/search?q=Ahmed%20Hashim"> Ahmed Hashim</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Polymer nano composites of polyvinylpyrrolidone and poly-ethylene glycol with different concentrations of aluminum oxide (Al2O3) nano particles have been prepared by solution cast method. The optical characterizations have been done by analyzing the absorption (A) spectra in the 300–800 nm spectral region. It was found that the optical energy gap decreases with the increasing of Al2O3 nano particles content. The optical constants (refractive index, extinction coefficient, real and imaginary parts of the dielectric constant) are changing with increasing aluminum oxide nano particle concentrations. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=nanocomposites" title="nanocomposites">nanocomposites</a>, <a href="https://publications.waset.org/abstracts/search?q=polyvinylpyrrolidone" title=" polyvinylpyrrolidone"> polyvinylpyrrolidone</a>, <a href="https://publications.waset.org/abstracts/search?q=optical%20constants" title=" optical constants"> optical constants</a>, <a href="https://publications.waset.org/abstracts/search?q=polymers" title=" polymers"> polymers</a>, <a href="https://publications.waset.org/abstracts/search?q=blend" title=" blend"> blend</a> </p> <a href="https://publications.waset.org/abstracts/32971/the-effect-of-aluminum-oxide-nanoparticles-on-the-optical-properties-of-pvp-peg-blend" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/32971.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">424</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">241</span> A Benchmark for Some Elastic and Mechanical Properties of Uranium Dioxide</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=E.%20G%C3%BCler">E. Güler</a>, <a href="https://publications.waset.org/abstracts/search?q=M.%20G%C3%BCler"> M. Güler</a> </p> <p class="card-text"><strong>Abstract:</strong></p> We present some elastic parameters of cubic fluorite type uranium dioxide (UO2) with a recent EAM type interatomic potential through geometry optimization calculations. Typical cubic elastic constants, bulk modulus, shear modulus, young modulus and other related elastic parameters were calculated during research. After calculations, we compared our results not only with the available theoretical data but also with previous experimental results. Our results are consistent with experiments and compare well the former theoretical results of the considered parameters of UO2. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=UO2" title="UO2">UO2</a>, <a href="https://publications.waset.org/abstracts/search?q=elastic%20constants" title=" elastic constants"> elastic constants</a>, <a href="https://publications.waset.org/abstracts/search?q=bulk%20modulus" title=" bulk modulus"> bulk modulus</a>, <a href="https://publications.waset.org/abstracts/search?q=mechanical%20properties" title=" mechanical properties"> mechanical properties</a> </p> <a href="https://publications.waset.org/abstracts/35108/a-benchmark-for-some-elastic-and-mechanical-properties-of-uranium-dioxide" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/35108.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">412</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">240</span> Thermal Behaviors of the Strong Form Factors of Charmonium and Charmed Beauty Mesons from Three Point Sum Rules</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=E.%20Yaz%C4%B1c%C4%B1">E. Yazıcı</a>, <a href="https://publications.waset.org/abstracts/search?q=H.%20Sundu"> H. Sundu</a>, <a href="https://publications.waset.org/abstracts/search?q=E.%20Veli%20Veliev"> E. Veli Veliev</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In order to understand the nature of strong interactions and QCD vacuum, investigation of the meson coupling constants have an important role. The knowledge on the temperature dependence of the form factors is very important for the interpretation of heavy-ion collision experiments. Also, more accurate determination of these coupling constants plays a crucial role in understanding of the hadronic decays. With the increasing of CM energies of the experiments, researches on meson interactions have become one of the more interesting problems of hadronic physics. In this study, we analyze the temperature dependence of the strong form factor of the BcBcJ/ψ vertex using the three point QCD sum rules method. Here, we assume that with replacing the vacuum condensates and also the continuum threshold by their thermal version, the sum rules for the observables remain valid. In calculations, we take into account the additional operators, which appear in the Wilson expansion at finite temperature. We also investigated the momentum dependence of the form factor at T = 0, fit it into an analytic function, and extrapolate into the deep time-like region in order to obtain a strong coupling constant of the vertex. Our results are consistent with the results existing in the literature. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=QCD%20sum%20rules" title="QCD sum rules">QCD sum rules</a>, <a href="https://publications.waset.org/abstracts/search?q=thermal%20QCD" title=" thermal QCD"> thermal QCD</a>, <a href="https://publications.waset.org/abstracts/search?q=heavy%20mesons" title=" heavy mesons"> heavy mesons</a>, <a href="https://publications.waset.org/abstracts/search?q=strong%20coupling%20constants" title=" strong coupling constants"> strong coupling constants</a> </p> <a href="https://publications.waset.org/abstracts/74337/thermal-behaviors-of-the-strong-form-factors-of-charmonium-and-charmed-beauty-mesons-from-three-point-sum-rules" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/74337.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">189</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">239</span> Elastic Constants of Heat Treated Wood</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ergun%20Guntekin">Ergun Guntekin</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Effects of heat treatment on elastic constants of Black pine (Pinus nigra) wood were investigated. Specimens were exposed to heat under atmospheric pressure at two different temperatures (180 and 210 °C) and three different time levels (2, 5, 8 hours). Three Young’s modulus in three anatomical directions, six Poisson’s ratios and three Shear modulus values associated with the main directions were evaluated by compression tests. Compression strength of the samples in three principal directions was also determined. All of the properties of the specimens tested were altered by heat treatment. The degree of alteration depends on the temperature as well as duration applied. Results indicate that EL and compression strength in L direction were not significantly influenced, compression strength in R direction significantly decreased, ER, ET and compression strength in T direction were increased for shorter periods, then dropped for 8-hour application of 180 ºC. ER was not significantly affected, compression strength in R direction and EL was significantly decreased, ET and compression strength in T direction were increased for shorter periods, then decreased for 8-hour application of 210 ºC. The shear modulus of the samples was decreased with application of treatment combinations. Most of the Poisson’s ratios were not affected by heat treatment. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=black%20pine" title="black pine">black pine</a>, <a href="https://publications.waset.org/abstracts/search?q=elastic%20constants" title=" elastic constants"> elastic constants</a>, <a href="https://publications.waset.org/abstracts/search?q=heat%20treatment" title=" heat treatment"> heat treatment</a>, <a href="https://publications.waset.org/abstracts/search?q=wood" title=" wood"> wood</a> </p> <a href="https://publications.waset.org/abstracts/90755/elastic-constants-of-heat-treated-wood" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/90755.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">155</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">238</span> Analysis of Structural Phase Stability of Strontium Sulphide under High Pressure</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Shilpa%20Kapoor">Shilpa Kapoor</a>, <a href="https://publications.waset.org/abstracts/search?q=Namrata%20Yaduvanshi"> Namrata Yaduvanshi</a>, <a href="https://publications.waset.org/abstracts/search?q=Pooja%20Pawar"> Pooja Pawar</a>, <a href="https://publications.waset.org/abstracts/search?q=Sadhna%20Singh"> Sadhna Singh</a> </p> <p class="card-text"><strong>Abstract:</strong></p> A Three Body Interaction Potential (TBIP) model is developed to study the high pressure phase transition of SrS having NaCl (B1) structure at room temperature. This model includes the long range Columbic, three body interaction forces, short range overlap forces operative up to next nearest neighbors and zero point energy effects. We have investigated the phase transition with pressure, volume collapse and second order elastic constants and found results well suited with available experimental data. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=phase%20transition" title="phase transition">phase transition</a>, <a href="https://publications.waset.org/abstracts/search?q=second%20order%20elastic%20constants" title=" second order elastic constants"> second order elastic constants</a>, <a href="https://publications.waset.org/abstracts/search?q=three%20body%20interaction%20forces" title=" three body interaction forces"> three body interaction forces</a>, <a href="https://publications.waset.org/abstracts/search?q=volume%20collapses" title=" volume collapses"> volume collapses</a> </p> <a href="https://publications.waset.org/abstracts/30522/analysis-of-structural-phase-stability-of-strontium-sulphide-under-high-pressure" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/30522.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">527</span> </span> </div> </div> <ul class="pagination"> <li class="page-item disabled"><span class="page-link">&lsaquo;</span></li> <li class="page-item active"><span class="page-link">1</span></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=cosmological%20constants&page=2">2</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=cosmological%20constants&page=3">3</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=cosmological%20constants&page=4">4</a></li> <li class="page-item"><a class="page-link" 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