337 research outputs found
Study Of Inertia And Stoichiometric Effect On Surface Diffusion By Monte Carlo Method
In this work, we investigate the inertia and stoichiometric effect on surface diffusion of adsorbates particles. The study is done by means of Monte-Carlo simulation in the framework of the lattice gas model. Only first neighboring repulsive pair interaction is considered. We concentrate on the behaviour of the tracer diffusion coefficient Dt(θ), as a function of surface coverage θ in the case where two type of particles A and B are adsorbed. A and B are only different by their mass. The results shows that θt ordering phenomenon is not strongly influenced. However the diffusion process is decreased by inclusion of heavy particles.w.In this work, we investigate the inertia and stoichiometric effect on surface diffusion of adsorbates particles. The study is done by means of Monte-Carlo simulation in the framework of the lattice gas model. Only first neighboring repulsive pair interaction is considered. We concentrate on the behaviour of the tracer diffusion coefficient Dt(θ), as a function of surface coverage θ in the case where two type of particles A and B are adsorbed. A and B are only different by their mass. The results shows that θt ordering phenomenon is not strongly influenced. However the diffusion process is decreased by inclusion of heavy particles.w
Phase-field modelling of dendritic growth behaviour towards the cooling / heating of pure nickel
We are interested in modelling the dendritic growth occurring during the solidification process of a pure material and especially to see the effect of the cooling / heating on the growth behaviour of this dendrite. For this purpose we use a phase-field model. The obtained partial differential equations are solved numerically by a finite difference method. In order to appreciate the shape of the resulting dendrites we expose some figures obtained from simulations in 2D.We are interested in modelling the dendritic growth occurring during the solidification process of a pure material and especially to see the effect of the cooling / heating on the growth behaviour of this dendrite. For this purpose we use a phase-field model. The obtained partial differential equations are solved numerically by a finite difference method. In order to appreciate the shape of the resulting dendrites we expose some figures obtained from simulations in 2D
Fibromatose desmoĂŻde de la mandibule
La tumeur desmoïde ou fibromatose agressive est une tumeur bénigne du tissu fibreux caractérisée par un haut potentiel d’envahissement locorégional. Sa localisation mandibulaire est exceptionnelle. Nous rapportons le cas d’un garçon de 2 ans, qui a présenté une défigurante fibromatose desmoïde de la mandibule. Le diagnostic a été posé par l’étude histologique d’une biopsie tumorale. Le traitement a consisté en une exérèse chirurgicale large. Aucun signe de récidive n’est survenu après 9 mois de suivi.Mots clés : tumeur desmoïde, fibromatose agressive, mandibul
The Preeminence of Gold and Silver as Money
Historically, money is gold and silver, supplied by the market on profit criterion. Everywhere, government inconvertible paper money arose from bankruptcy. A government with balanced budgets would never need it. Imposed by force, inconvertible paper is a taxation mean, highly inflationary, and causes impoverishment. Unjust and bankrupt governments will continue to force this despotic money. Islamic Monetary Economics refutes the idea of money as a policy tool. Fully convertible paper is Shariah compliant. Shariah requires a just government to balance its budgets and restore fully gold and silver as lawful money
Financial Stability of Conventional and Islamic Banks: A Survey
This paper surveys the financial stability of conventional and Islamic banking. The stability of the financial system requires a greater role for equity and risk-sharing and tying the credits to the real economy. The rate of profit model (SR) proves the inferiority of the interest or fixed return (FR) contract model, and contributes significantly to the stability of a financial system; namely there is no debt expansion and contraction and the real investment might be higher in the SR model than in the FR model. Islamic Banks have shown relative stability to the first wave of the last international crisis of 2007-2008 and then contributed to reducing the volatility of global financial markets. The paper surveyed many empirical papers that use
quantitative models to analyze the financial stability of the Islamic and conventional banks. The findings indicate that small Islamic banks are more stable than small conventional banks; large conventional banks are more stable than large Islamic banks; Islamic banks have been
affected by the crisis; and traditional banks may be more competitive than the Islamic banks. In respect to business orientation, efficiency, risk-taking, and stability, some empirical papers find little significant differences between Islamic and conventional banks. The central bank
policy to stabilize the price level or to smooth the interest rate changes seemed to enhance banking stability
The Preeminence of Gold and Silver as Money
Historically, money is gold and silver, supplied by the market on profit criterion. Everywhere, government inconvertible paper money arose from bankruptcy. A government with balanced budgets would never need it. Imposed by force, inconvertible paper is a taxation mean, highly inflationary, and causes impoverishment. Unjust and bankrupt governments will continue to force this despotic money. Islamic Monetary Economics refutes the idea of money as a policy tool. Fully convertible paper is Shariah compliant. Shariah requires a just government to balance its budgets and restore fully gold and silver as lawful money
The Preeminence of Gold and Silver as Shariah Money
Historically, money is gold and silver, supplied by the market on profit criterion. Everywhere, government inconvertible paper money arose from bankruptcy. A government with balanced budgets would never need it. Imposed by force, inconvertible paper is a taxation mean, highly inflationary, and causes impoverishment. Unjust and bankrupt governments will continue to force this despotic money. Islamic Monetary Economics refutes the idea of money as a policy tool. Fully convertible paper is Shariah compliant. Shariah requires a just government to balance its budgets and restore fully gold and silver as lawful money
Assessment of optical aberrations of tunable liquid crystal cylindrical microlenses
[Poster of]: XX Conference on Liquid Crystals: Chemistry, Physics and Applications (CLC 2013), 15-20 September, 2018, Mikolajki, Poland.Cylindrical lenses are promising devices for a wide range of applications [1-3]. This kind
of lenses can be used in some novel applications such as light-sheet microscopy, line
illumination microscopy or autostereoscopic devices. However, as any kind of lens, the main
drawback is the generation of optical aberrations. These aberrations determine the image
quality of an optical system. Interferometrists often like to represent wavefronts as Zernike
polynomials. Zernike polynomials have been widely used because, unlike other polynomial
set, they are orthogonal over a unit circle and represent balanced classical optical aberrations,
yielding minimum variance over a circular pupil [4]. These characteristics are lost when non
circular pupils are employed. Some research works have developed new coefficients for
different pupils [5]. Notwithstanding that, they were targeted for rotational symmetric optics
[6]. In the referred paper, 2D Chebyshev polynomials related to some Seidel aberrations are
described. These ones form a useful orthogonal basis for optics of rectangular apertures,
making them an attractive option for cylindrical lenses.
In this work, optical aberrations in a liquid crystal (LC) cylindrical lens have been modeled
and measured, for the first time. We have developed our own application specifically to
extract the 3D wavefront from an interference pattern. This software tool also allows us to
obtain the optical aberrations based on Chebyshev polynomials. A tunable LC cylindrical lens
has been designed and manufactured. Optical aberrations have been assessed by adjusting the
control voltage applied to the device.The authors acknowledge funding support from Spanish Ministerio de EconomĂa y Competitividad (grant nÂş TEC2009-13991-C02-01) and Comunidad de Madrid (grant nÂş FACTOTEM S2009/ESP-1781
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