In this paper, the non-linear response spectra of elastoplastic systems with constant ductility for three accelerograms which were obtained by linear interpolation method of excitation and also by using cubic spline function are compared with each other. Non-linear response spectra were calculated for ductility of 1, 1.5, 2, 4 and 8. For a more detailed analysis, the time interval between the accelerogram points was divided into 2, 5, 10, 20, 50 and 100 equal parts, respectively, and new accelerograms were produced once using linear interpolation and once using spline interpolation, and the non-linear response spectra of these two types of accelerograms were compared. The results of the work indicated that the maximum and minimum values had significant values. In addition, in most cases, the maximum value of the difference was greater than the absolute value of the corresponding minimum difference. Also, in most periods, the spectral values did not differ much, but in small periods, which are related to stiff structures, the amount of difference was significant.

In this paper, the pseudo-acceleration spectra of the three accelerograms of El Centro, Naghan and Tabas, which were obtained by the linear interpolation method of stimulation (Jennings’s method) and also by using the cubic spline function, are compared with each other. Jennings' method is based on linear interpolation of excitation and is acceptable for short periods of time. In this research, three accelerograms of El Centro, Naghan and Tabas were considered, and their pseudo-acceleration response spectrum (base shear coefficient) was calculated for different damping values using linear interpolation method and interpolation with spline function. The considered damping were zero, two, five, ten and twenty percent. In order to determine the difference between the linear interpolation method and the spline function interpolation method, the time interval between the accelerometer points was divided into 2, 5, 10, 20, 50, 100, and 200 equal parts, respectively. Then, once with the linear interpolation method and again with the spline interpolation method, the internal points between the internal acceleration points were obtained and their pseudo-acceleration spectrum was calculated using the Jennings method and the interpolation method with the spline function. The calculation results showed that the pseudo-acceleration spectrum values calculated by the spline interpolation method in very short periods and low damping have a significant difference with the corresponding values of the pseudo-acceleration spectrum calculated by the linear interpolation method. It should be noted that the initial time interval between the accelerogram points of El Centro, Naghan and Tabas is 0.02 seconds.

Introduction: Myocardial SPECT imaging is usually performed acquiring 32 views in 180 degree with equal steps of 5.625 degrees. Acquiring more images requires spending more time or injection of more activity to the patients. An idea to improve the quality reconstructed images without acquiring extra images is producing the extra images interpolating the data between adjacent projections. The aim of present study was investigation the feasibility of this idea.Methods: Obviously such investigation cannot be performed on real patient's data. Therefore, data were simulated using NCAT digital phantom and SimSET Monte Carlo code. The imaging was performed as usual, acquiring 32 views from right anterior oblique to left posterior oblique. The data were interpolated to construct 5 images between adjacent projections convert it into 187 projections. The simulation was performed again acquiring 187 images as the reference. The conventional, interpolated and reference data set were reconstructed and compared for improvement and degradation in quality of final images. The above procedure was repeated for phantoms representing different types of heart disease, different cardiac size and different count densities.Results: The results showed that Hermit interpolation technique produces better quality images comparing to other interpolation methods tested. Results also confirmed that streak artifacts decreases, signal to noise ratio and contrast increased due to increasing the number of samples.Conclusion: These results indicate that the physical properties of reconstructed images improve significantly.This directly must improve the lesions delectability of images. However the matter is still under investigation.

In this study random vibration of a cantilever tapered beam under distributed stationary stochastic excitation with Gaussian probability density function is investigated. early free vibration analysis is performed to obtain the mode shapes of beam in form of Bessel functions, then the response is described in summation of mode shapes, and auto correlation of response is shaped by considering the mode shapes of tapered beam, also spectral density matrix of excitation is derived with cooperation of mode shapes and two dummy variables. in next step by means of frequency response and taking Fourier integral of autocorrelation of response, spectral density of displacement is computed and by using spectral density of displacement, variance of random displacements for various positions along the beam are achieved. Finally elasticity equation is applied to derive random strain and stress of beam. Comparing the variance of random stress with yield stress of beam leads to obtain probability of beam failure.

A potential energy surface, describing the behavior of the title reaction, has been constructed by interpolation of ab initio data. H2O, NH, HON, HNO, NH3, O, H2NO, cis or trans-HONH, H products, two vibrationally energized NH2OH* and NH3O* adducts were observed. The reaction probabilities, effective cross sections, and branching ratios for different channels are reported. The rate constant for the formation of the NH2OH* is calculated as a function of effective cross section and is compared with the available data in the literature. The calculated QCT rate constant for the formation of NH2OH was found to be lower than that reported in our previous study (J. Phys. Chem. A, 113, 12961, 2009) based on the RRKM method with steady state assumption for the formation of energized adducts that could be due to the lack of the stabilization process in QCT calculations.

In this work the notion of a bornological linearly topologized module over a discrete valuation ring is introduced and it is shown that certain semimetrizable linearly topologized modules are bornological. The main result is a characterization of bornological linearly topologized modules, from which the completeness and the quasi-completeness of certain linearly topologized modules of continuous linear mappings are derived.