Because of mass assignment onto grid points in the measurement of the power spectrum using the Fast Fourier Transform (FFT), the raw power spectrum |δ f (k)| 2 estimated with FFT is not the same as the true power spectrum P (k). In this paper, we derive the formula which relates |δ

in this pepper fe2o3 nanoparticles were synthesized via a fast microwave method. then fe2o3-tio2 nanocomposites were synthesized by a sonochemical-assisted method. the prepared products were characterized by x-ray diffraction pattern, scanning electron microscopy and fourier transform infrared spectroscopy. the photocatalytic behaviour of fe2o3-tio2 nanocomposites was evaluated using the degrad...

zns  nanoparticles  were  synthesized  via  a  simple  surfactant  free microwave  route.  in  this  synthesis, thioacetamide  was  used  as sulfur  source.  the effects  of different  parameters  such  as  type of zinc precursor,  time  and  power  of  irradiation  on  the  morphology and  particle  size  of  the  products  have been  investigated.  the nanostructures  were  characterized  by ...

where w(n) is an analysis window. At each time instant, the STFT is a discrete-time Fourier transform or discrete Fourier transform (DFT). Many DFT computing algorithms and architectures have been proposed. However, the direct use of the DFI' without considering the special sliding window effect of STFT is not an efficient approach. There are two major approaches for STFT. One is based on the f...

Optical structures to implement the discrete Fourier transform (DFT) and fast Fourier transform (FFT) algorithms for discretely sampled data sets are considered. In particular, the decomposition of the FFT algorithm into the basic Butterfly operations is described, as this allows the algorithm to be fully implemented by the successive coherent addition and subtraction of two wavefronts (the sub...

glycerol mono-oleate (gmo) was produced by direct esterification reaction with amberlyst 16 resin catalysts with the efficiency of 86% and was used as a surfactant for synthesis of cofe2o4 nano-particles by surfactant-assisted microwave method. fourier transform infrared spectroscopy (ft-ir), x-ray diffraction (xrd) and scanning electron microscopy (sem) were used to consider the structural and...

A new wavelet transform (WT) is introduced based on the fractional properties of the traditional Fourier transform. The new wavelet follows from the fractional Fourier order which uniquely identifies the representation of an input function in a fractional domain. It exploits the combined advantages of WT and fractional Fourier transform (FrFT). The transform permits the identification of a tran...

al2o3-sio2 diphasic gel was synthesized by sol gel route from aluminium nitrate and silicic acid following aqueous phase colloidal interaction. the precursor gel powder was thoroughly characterized by chemical analysis, measurement of surface area and bulk density measurement. the gel powder was further characterized by thermogravimetry, xrd diffraction study of the heat treated samples and sca...

The Fourier Transform-Raman and Fourier Transform-Infrared spectra of 5-bromo-2-nitropyridine have been recorded. The observed frequencies were assigned to various modes of vibrations on the basis of normal coordinate calculations, assuming CS point group symmetry. The potential energy distribution associated with normal modes is also reported here. The assignment of fundamental vibrations agre...