Results 1 - 10 of 3497
Results 1 - 10 of 3497. Search took: 0.032 seconds
|Sort by: date | relevance|
[en] We present the spectroscopic variations of 14 program Be stars observed within 2008 – 2009 at the Bosscha Observatory, Lembang, Indonesia, using Zeiss Double Refractor equipped with Bosscha Compact Spectrograph. The Be stars show spectroscopic profiles as Be and Beshell, and sometimes as B-normal. These profiles originate from the disk-like envelope or rings surrounded the star’s equatorial plane. Our program stars are: 5 as Be single-peaked, 2 as Be double-peak, and 7 as B-normal stars. We also measure the Ip/Ic ratio from the line profiles. (paper)
[en] An algorithm based on moment estimation is presented to determine the initial parameters of the particle spectrum peak shape function for the iteration fitting procedure. The algorithm calculates the mean value, variance, and third-order central moment by using the spectrum peak data, solves the parameters of the fitting function, and then provides them as the initial values to the Levenberg–Marquardt algorithm to ensure convergence and optimized fitting. The effectiveness of the proposed algorithm was tested by gamma and alpha spectra. The algorithm can be used in automated peak curve fitting and spectral analysis. - Highlights: • The proposed algorithm was based on moment estimation. • Initial parameters of the particle spectrum peak shape function were estimated. • The Levenberg–Marquardt algorithm was used to fit the spectrum peak. • The proposed algorithm was applied to analyze gamma and alpha spectra.
[en] The energy e and intensity of the 246Cm alpha groups are measured using a curium sample extracted from the spent fuel of a npp with the wwer-440 reactor. The 245Cm isotope was used as an energy standard (sub(αsub(169 9))=5362.0+-0.7 keV; isub(αsub(169))=93.2+-0.5%. The following values of 246Cm nuclear-physical constants are obtained: esub(αsub(0))=5386.5+-1.0 0 keV; isub(αsub(0))=82.2+-1.2%; esub(αsub(45))=5343.5+-1.0 keV; isub(αsub(45))=17.8+-1.2%
[en] One of the powerful auxiliary to nuclear geophysics is the obtention and interpretation of the alpha and gamma radiation spectra. This work discuss, qualitative and quantitative, the lost information problem, motivated by the noise in the process of information codification. The decodification process must be suppield by the appropriate mathematical model on the measure system to recovery the information from nuclear source. (C.D.G.)
[pt]Uma das ferramentas mais poderosas da Geofisica Nuclear e a obtencao e interpretacao dos espectros de radiacao alfa e gama. Discute-se neste trabalho, de maneira qualitativa o problema de perda de informacao devida a introducao de ruido no processo de codificacao da informacao. O processo de decodificacao deve ser suprido de um modelo adequado do sistema de medida para restituir a contento a informacao sobre a fonte nuclear. (autor)