2,450 research outputs found

    Two bonded half planes with a crack going through the interface

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    The plane problem of two bonded elastic half planes containing a finite crack perpendicular to and going through the interface is considered. The problem is formulated as a system of singular integral equations with generalized Cauchy kernels. Even though the system has three irregular points, it is shown that the unknown functions are algebraically related at the irregular point on the interface and the integral equations can be solved by a method developed previously. The system of integral equations is shown to yield the same characteristic equation as that for two bonded quarter planes in the general case of the through crack, and the characteristic equation for a crack tip terminating at the interface in the special case. The numerical results given in the paper include the stress intensity factors at the crack tips, the normal and shear components of the stress intensity factors at the singular point on the interface, and the crack surface displacements

    Testing for convergence in stock markets: A non-linear factor approach

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    This paper applies the Phillips and Sul (2007) method to test for convergence in stock returns to an extensive dataset including monthly stock price indices for five EU countries (Germany, France, the Netherlands, Ireland and the UK) as well as the US over the period 1973-2008. We carry out the analysis on both sectors and individual industries within sectors. As a first step, we use the Stock and Watson (1998) procedure to filter the data in order to extract the long-run component of the series; then, following Phillips and Sul (2007), we estimate the relative transition parameters. In the case of sectoral indices we find convergence in the middle of the sample period, followed by divergence, and detect four (two large and two small) clusters. The analysis at a disaggregate, industry level again points to convergence in the middle of the sample, and subsequent divergence, but a much larger number of clusters is now found. Splitting the cross-section into two subgroups including Euro area countries, the UK and the US respectively, provides evidence of a global convergence/divergence process not obviously influenced by EU policies

    Penny-shaped crack in a fiber-reinforced matrix

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    Using a slender inclusion model developed earlier, the elastostatic interaction problem between a penny-shaped crack and elastic fibers in an elastic matrix is formulated. For a single set and for multiple sets of fibers oriented perpendicularly to the plane of the crack and distributed symmetrically on concentric circles, the problem was reduced to a system of singular integral equations. Techniques for the regularization and for the numerical solution of the system are outlined. For various fiber geometries numerical examples are given, and distribution of the stress intensity factor along the crack border was obtained. Sample results showing the distribution of the fiber stress and a measure of the fiber-matrix interface shear are also included

    Analytic and asymptotic properties of generalized Linnik probability densities

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    Cataloged from PDF version of article.This paper studies the properties of the probability density function pα,Îœ,n(x) of the n-variate generalized Linnik distribution whose characteristic function φα,Îœ,n(t) is given by where {norm of matrix}t{norm of matrix} is the Euclidean norm of t ∈ ℝn. Integral representations of pα,Îœ,n(x) are obtained and used to derive the asymptotic expansions of pα,Îœ,n(x) when {norm of matrix}x{norm of matrix}→0 and {norm of matrix}x{norm of matrix}→∞ respectively. It is shown that under certain conditions which are arithmetic in nature, pα,Îœ,n(x) can be represented in terms of entire functions. © 2009 BirkhĂ€user Boston

    Qualitative features of periodic solutions of KdV

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    In this paper we prove new qualitative features of solutions of KdV on the circle. The first result says that the Fourier coefficients of a solution of KdV in Sobolev space HN, N≄0H^N,\, N\geq 0, admit a WKB type expansion up to first order with strongly oscillating phase factors defined in terms of the KdV frequencies. The second result provides estimates for the approximation of such a solution by trigonometric polynomials of sufficiently large degree

    Filament activated chemical vapor deposition of boron carbide coatings

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    In this study, we have demonstrated that boron carbide, an extremely hard and wear‐resistant material, can be deposited with hot filament‐activated chemical vapor deposition (HFCVD). There are several benefits to using a hot filament system, including a high deposition rate and a relatively low substrate temperature with a process that is not line‐of‐sight. High purity, apparently amorphous boron carbide films were obtained by the use of a chlorine based precursor (which is less toxic than diborane). This indicates that either the hot filament helps in complete decomposition of BCl3 or the presence of high concentration of atomic hydrogen in a HFCVD environment helps in scavenging the chlorine. © 1994 American Institue of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70919/2/APPLAB-65-14-1757-1.pd

    Ultraviolet light induced changes in polyimide liquid‐crystal alignment films

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    Ultraviolet light induced changes in polyimide liquid‐crystal alignment films were investigated. Infrared, UV‐visible, x‐ray photoelectron spectroscopy, and electron‐spin‐resonance measure‐ ments indicated that bond breaking and subsequent oxidation reactions occur in polyimide films (SE7210, OCG284, DuPont 2555 and 2540) during the broadband UV illumination in air. Mechanical rubbing has no effect on the optical and magnetic properties but it causes the removal of the UV‐exposed film. Capacitance–voltage measurements indicate that there is a slight decrease in dielectric constant and creation of net negative charges in the film after UV exposure. Sur‐ face tension of polyimide films before and after UV illumination and changes in the pretilt angle of the polyimide surface following UV exposure have also been studied. The decrease in pretilt angle following UV illumination is attributed to an increase in surface tension. Our results indicate that a simple UV technique can be used to achieve domain divided liquid‐crystal pixel electrode design with improved viewing characteristics. © 1996 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70453/2/JAPIAU-80-9-5028-1.pd

    Near-linear dynamics in KdV with periodic boundary conditions

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    Near linear evolution in Korteweg de Vries (KdV) equation with periodic boundary conditions is established under the assumption of high frequency initial data. This result is obtained by the method of normal form reduction

    Effects of Prolonged Intravenous Flunixin Meglumine in Healthy Dogs

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    This study was designed to evaluate possible side effects on liver and kidney functions and haematological indices, associated with long-term intravenous (IV) administration of flunixin meglumine in healthy dogs. For this purpose, 12 dogs were divided into 2 equal groups. Group 1 was intravenously given flunixin meglumine at the dose of 1.1 mg/kg/day for 5 days and g-roup 11 received 2.2 mg/kg/day IV for 5 days. Blood samples were withdrawn before treatment (day 0), 2 h post injection on each day of treatment and one day after the last injection for biochemical (glucose, sodium-Na, potassium-K, chloride-Cl, creatinine, urea, alkaline phosphatase-AP, alanine amino transferase-ALT and total protein) and haematological (bleeding time, coagulation time, red blood cell, white blood cell, platelet count, differential leukocyte count, haematocrit and haemoglobin) analyses. Faecal and urine samples were collected on the same days as blood samples for the presence of any abnormalities. The results revealed a significant increase in bleeding (P < 0.001) and coagulation time (P < 0.001) and a decrease in platelet count (P < 0.001) in both groups. There was also a significant increase in the concentration of Na and Cl in group 1 and an elevation in AP (P < 0.00 07 ALT (P < 0.001) and glucose (P < 0.001) in group II. Blood in urine and faeces was also evident in both groups. The results may suggest that the dose of 1.1 mg/kg IV for 5 d does not cause any significant side effects provided that no bleeding disorder exists. and the dose of 2.2 mg/kg IV for 5 d should not exceed 3 d as liver enzymes began to increase significantly afterwards
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