We study two galaxies samples selected in ultraviolet (UV) and in far infrared (FIR) for which the spectral energy distributions (SEDs) from the far UV (FUV) to the FIR are available. We compare the observed SEDs to modelled SEDs with several star formation histories (SFHs; decaying star formation rate plus burst) and dust attenuation laws (power law + 2175Å bump). The Bayesian method allows to...

In modern PET scanners, image reconstruction is performed sequentially in two steps regardless of the reconstruction method: 1. Attenuation correction factor computation (ACF) from transmission scans, 2. Emission image reconstruction using the computed ACFs. This reconstruction scheme does not use all the information in the transmission and emission scans. Post-injection transmission scans cont...

X-band dual-polarization phased-array weather radars (X-PARs) have been used in South China extensively. Eliminating the attenuation and system bias of radar data is key to utilizing advantage X-PAR networks. In this paper, disdrometer raindrop-size distribution (DSD) measurements are calculate polarimetric variables analyze characteristics precipitation attenuation. Furthermore, based on netwo...

  Introduction: Monte Carlo (MC) is the most common method for simulating virtual SPECT projections. It is useful for optimizing procedures, evaluating correction algorithms and more recently image reconstruction as a forward projector in iterative algorithms; however, the main drawback of MC is its long run time. We introduced a model based method considering the eff...

The present paper deals with the analysis and development of noise-reduction transformer that has a filter function for conductive noise transmission. Two types of prototype noise-reduction transformers with two different output voltages are proposed. To determine an optimum design for the noise-reduction transformer, noise attenuation characteristics are discussed based on the experiments and ...

Introduction: We aimed to investigate the effect of right bundle branch block (RBBB) on perfusion and functional parameters in dipyridamole stress/rest Tc99m-MIBI gated myocardial perfusion SPECT (GSPECT) which may be helpful in interpretation of myocardial perfusion imaging. Methods: We studied 73 patients with low pre-test likelihood of coronary artery disease in two groups:  38 patients wit...

In the work attenuation regularities of acoustic signals, which propagate in closed chambers, are analysed. Due to this that in a closed chamber gases state parameters are interdependent, so change of one of the parameters results in corresponding changes of others. Usually the closed chambers are of constant volume or constant pressure, therefore influence of temperature variations on air para...

Introduction: Protecting the vital organs in radiation therapy is one of the most important issues. Cerrobend alloy, the most common material used as the shield, is melted several times and used for different patients. In this study changes in attenuation coefficient of cerrobend due to melting was investigated.   Materials and Methods: In melting furnace, ...

abtract background: in nuclear medicine, phantoms are mainly used to evaluate the overall performance of the imaging systems and practically there is no phantom exclusively designed for the evaluation of the software performance.  in this study the hoffman brain phantom was used for quantitative evaluation of reconstruction techniques. the phantom is modified to acquire tomographic and planar i...