763 research outputs found
Nonexistense of global solutions of a quasilinear bi-hyperbolic equation with dynamical boundary conditions
In this work, the nonexistence of the global solutions to a class of initial boundary value problems with dissipative terms in the boundary conditions is considered for a quasilinear system of equations. The nonexistence proof is achieved by the use of a lemma due to O. Ladyzhenskaya and V.K. Kalantarov and by the usage of the so called generalized convexity method. In this method one writes down a functional which reflects the properties of dissipative boundary conditions and represents the norm of the solution in some sense, then proves that this functional satisfies the hypotheses of Ladyzhenskaya-Kalantarov lemma. Hence from the conclusion of the lemma one deduces that in a finite time , this functional and hence the norm of the solution blows up
Any -state solutions of the Hulth\'en potential by the asymptotic iteration method
In this article, we present the analytical solution of the radial
Schr\"{o}dinger equation for the Hulth\'{e}n potential within the framework of
the asymptotic iteration method by using an approximation to the centrifugal
potential for any states. We obtain the energy eigenvalues and the
corresponding eigenfunctions for different screening parameters. The wave
functions are physical and energy eigenvalues are in good agreement with the
results obtained by other methods for different values. In order to
demonstrate this, the results of the asymptotic iteration method are compared
with the results of the supersymmetry, the numerical integration, the
variational and the shifted 1/N expansion methods.Comment: 14 pages and 1 figur
Arbitrary l-state solutions of the rotating Morse potential by the asymptotic iteration method
For non-zero values, we present an analytical solution of the radial
Schr\"{o}dinger equation for the rotating Morse potential using the Pekeris
approximation within the framework of the Asymptotic Iteration Method. The
bound state energy eigenvalues and corresponding wave functions are obtained
for a number of diatomic molecules and the results are compared with the
findings of the super-symmetry, the hypervirial perturbation, the
Nikiforov-Uvarov, the variational, the shifted 1/N and the modified shifted 1/N
expansion methods.Comment: 15 pages with 1 eps figure. accepted for publication in Journal of
Physics A: Mathematical and Genera
The Energy Eigenvalues of the Two Dimensional Hydrogen Atom in a Magnetic Field
In this paper, the energy eigenvalues of the two dimensional hydrogen atom
are presented for the arbitrary Larmor frequencies by using the asymptotic
iteration method. We first show the energy eigenvalues for the no magnetic
field case analytically, and then we obtain the energy eigenvalues for the
strong and weak magnetic field cases within an iterative approach for
and states for several different arbitrary Larmor frequencies. The
effect of the magnetic field on the energy eigenvalues is determined precisely.
The results are in excellent agreement with the findings of the other methods
and our method works for the cases where the others fail.Comment: 13 pages and 5 table
Comparison of oxidation stability of virgin olive oils from different locations of Turkey
Ten kinds of virgin olive oil of two major cultivars (Ayvalık and Memecik) produced in several areas of Turkey (Bayındır, Edremit, Ortaklar, Burhaniye, Ezine, Tire, Havran, Ayvalık, Altınoluk, and Küçükkuyu) were analysed. The quality characteristics, fatty acid composition, total phenol, ando-diphenol content of the samples were determined. Oxidative stability and free radical scavenging activity were determined using Rancimat test, Schaal oven test, and DPPH method. It was found that while Memecik oil from Ortaklar demonstrated the strongest oxidative stability, Ayvalık oil from Ezine had the lowest oxidative stability among the samples. Fatty acid composition and especially oleic acid/linoleic acid ratio was previously defined as a parameter that can help distinguish cultivars from one another; however, this study proved that total phenol, especially o-diphenol content of the oil, has the strongest effect on oxidative stability compared to other factors including fatty acid composition
Neural Network-based Backcalculation Models for Non-Destructive Evaluation of Rigid Airfield Pavement Systems
Heavy Weight Deflectometer (HWD) tests were routinely conducted on three Portland Cement Concrete (PCC) test items in the Federal Aviation Administration’s (FAA\u27s) National Airport Pavement Test Facility (NAPTF) to verify the uniformity of the test pavement structures and to measure pavement responses during full-scale traffic testing. A six-wheel aircraft landing gear with dual-tridem configuration was trafficked on the north side of the test pavement while the south side was trafficked by a four-wheel landing gear with dual tandem configuration. HWD tests were conducted before and during traffic testing at slab center, at longitudinal joints and at transverse joints. Substantial corner cracking occurred in all three of the rigid pavement test items after 28 passes of traffic had been completed. Trafficking continued until the rigid items were deemed failed. This paper presents an Artificial Neural Networks (ANN) based approach for backcalculating the NAPTF rigid pavement properties. The study findings illustrate the complexity of backcalculating properties of rigid pavements subjected to full-scale dynamic traffic testing. Apart from other complicating factors such as the slab curling and warping behavior, the test pavements exhibited corner cracks within few passes of traffic loading which further complicated the interpretation of HWD test results
Neural Network-Based Approach for Analysis of Rigid Pavement Systems Using Deflection Data
This paper focuses on the development of backcalculation models based on artificial neural networks (ANNs) for predicting the layer moduli of the jointed plain concrete pavements, that is, the elastic modulus of the portland cement concrete (PCC) layer and the coefficient of subgrade reaction for the pavement foundation. The ANN-based models were trained to predict the layer moduli by using the falling-weight deflectometer (FWD) deflection basin data and the thickness of the concrete pavement structure. The ISLAB2000 finite element program, extensively tested and validated for more than 20 years, has been employed as an advanced structural model for solving the responses of the rigid pavement systems and generating a knowledge database. ANN-based backcalculation models trained with the results from the ISLAB2000 solutions have been found to be viable alternatives for rapid assessment (capable of analyzing 100,000 FWD deflection profiles in a single second) of the rigid pavement systems. The trained ANN-based models are capable of predicting the concrete pavement parameters with very low
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