Background & Aims: Nowadays, imaging of the blood supply of the heart muscle by single photon emission computed tomography (SPECT: Single Photon Emission Computed Tomography) due to its non-invasive nature and providing information with physiological value and low cost compared to the valuable angiography method. It is highly diagnostic. But these images undergo changes and artifacts under the influence of factors, the result of which is the reduction of the diagnostic accuracy of the images and false positive cases. During the detection process, several physical effects such as attenuation, scattering, and collimator response function affect the frequency of emitted photons,this leads to the destruction of the contrast and as a result of reducing the quantitative and qualitative accuracy of the images. Attenuation, as the most destructive factor of SPECT images, reduces the quality of SPECT images of heart blood supply and reduces the sensitivity of tests related to the diagnosis of coronary artery diseases, and for non-uniform environments, especially in nuclear imaging of chest areas. And the heart is necessary to produce a map of patient attenuation coefficients. The existence of scattered photons is also one of the main factors of error in quantization,the detection of scattered events affects the contrast of the lesions and causes the lack of image resolution and signal-to-noise ratio. Therefore, to correct the attenuation and scattering of the rays in the heart images quantitatively and qualitatively, patterns are needed in SPECT systems. Due to the importance of the topic, various research groups around the world have presented their research and results on correcting the effect of scattering of rays and also correcting the effect of weakening the rays. If there was no limitation of energy resolution, it was easily possible to identify the scattered rays and prevent them from being recorded in the image. Because we know that scattered rays lose energy. Because gamma rays are single energy and their energy amount is completely known. Therefore, each photon with less energy will represent scattered rays, but due to the limited energy resolution of the gamma camera, a range is usually considered on the sides of the main energy, which is called the energy window. It is assumed that the photons recorded in this energy range are primary photons, but in fact, many photons scattered in the body are also recorded in this window. These scattered rays do not carry correct spatial information and lead to a decrease in image resolution and contrast and quantization errors in the image. In nuclear medicine, instead of researching and examining the patient or processing the image of the patient, simulated images can be examined. Simulators can provide information about each of the image destruction factors. The purpose of this research is to propose a new method for scattering correction, in this research, a combination of Monte Carlo and modeling is used for the rapid production of scattered views, and in the proposed method, the two-matrix method is used, this method At the stage of generating mathematical views, dispersion is added and this problem leads to the removal of scattered rays. As a result, an image is reconstructed that is free from the effects of attenuation and non-ideal dispersion and leads to an increase in contrast and improvement of power. Detecting waste, increasing the signal-to-noise ratio, and increasing the accuracy of quantification. Methods: In this study, the effect of applying attenuation and dispersion correction using two energy windows (DEW) and three energy windows (TEW) methods in cardiac aspect imaging was investigated and evaluated, and to simulate cardiac aspect imaging, a special code similar to SAR Monte Carlo GATE was used as the SPECT imaging system and XCAT digital phantom with activity distribution and realistic attenuation map was used to model the human trunk. Results: Comparison of image contrast improvement in different modes of attenuation and dispersion correction shows that the highest image contrast is obtained from the (TEW1+AC) method with an average increase of 25% and MSE in different modes of attenuation correction. And the dispersion compared to the reference image was reduced from 51. 5% to 54. 5%. Compared to the reference image, MSE decreased from 1. 4 in Un_Cor to 1. 15, 1. 13, 1. 12, and 1. 14 in AC+TEW1, AC+DEW, AC, and AC+TEW2, respectively, and the signal-to-noise ratio (SNR) increased up to 71% in all methods of applying dispersion correction along with attenuation correction compared to applying attenuation correction (AC). Conclusion: In this study, the effect of attenuation and dispersion correction in 5 non-correction modes, with attenuation correction, attenuation, and dispersion correction using two-window and three-window methods with triangular approximation and three-window with trapezoidal approximation on We evaluated XCAT phantom simulated images and heart muscle perfusion images by SPECT method and 4 different parameters were used to compare and evaluate the images, including profile, contrast, mean squared error (MSE) and signal to noise. According to the results of the quantification of reconstructed images, it is possible to apply dispersion correction along with attenuation correction.

Chitin is one of the most abundant biopolymers after cellulose, which is present in the cell wall of fungi, the cuticle of insects, and in the exoskeleton of crustaceans such as crabs and shrimps. From the deacetylation of chitin, chitosan is obtained, whose characteristics strongly depend on the degree of deacetylation and its molecular weight. In fact, it can be said that chitosan is the most abundant amino polysaccharide in nature, which is also known as a non-toxic compound. Chitosan has received much attention due to its unique properties such as biocompatibility, biodegradability, antibacterial activity, etc. But due to its low solubility in physiological pH, it is not possible to benefit from many of its properties. Therefore, many attempts have been made to produce its derivatives that have the ability to dissolve in such a condition. One of the most important methods of increasing the solubility of chitosan is its chemical modification, which is done with the so-called quaternization technique. In this method, a modifying agent by establishing a covalent bond with carbon number two of chitosan (C2) increases its solubility in water and at physiological pH. In this article, while re-introducing the unique features of chitosan, various methods of preparing quaternized chitosan using some common chemical compounds such as GTMAC, EPTMAC, CH3I, DMS will be investigated and the characteristics and applications of the produced quaternized chitosan will be described.

Low-frequency, high-amplitude surface wave (ground roll) is an old problem in land-based seismic field records. Conventional processing modules are to suppress ground- rolls, such as frequency and velocity filters, which use the Fourier transform. All of these techniques assume that the frequency contents of seismic trace are stationary, but in reality seismic traces have time varying frequency contents. In this study an alternative method to the Fourier transform known as the wavelet transform was used to suppress ground rolls. The key advantage of the wavelet transform over the Fourier transform is that it does not assume that the trace is stationary, and it can also localize the target information in the time-scale domain. The wavelet transform decomposes the seismic trace using basis functions that have finite extent in both frequency and time. In this research, an algorithm was prepared to take the wavelet transform of seismic traces of a shot record. Then a filter for ground roll suppression was designed based on the results of wavelet transform. Finally, the efficiency of this filter was compared to that of the band-pass and F-K filters.

From the perspective of scholars of hadith, accepting and trusting the narratives of a narrator depends on a variety of factors, lack of each result in distrust. However in special conditions, some of these inconveniences can be ignored and the narratives can be sentenced to correctness. Among these factors, lying and having reputation in heresy due to the great damage which imposes on the justice of narrators are the ones that according to scholars of both Shia and Sunni sects, without any exception, lead to distrust in a narrator’s narratives. In this article, reflecting on evidences in infallible Imams (PBUT) narratives and studying the statements of the experts on narrators (Rijal)., this theory has been proven that the two factors of lying and having reputation in heresy, can be seen more than all the Shiite narrators, in the extremists (ghalis) and therefore their fame for these two attributions is the most important cause of their weakness.

The isoseismal maps for 22 earthquakes in different regions of Iran were analyzed to study the attenuation of seismic intensity with the distance from the epicentre under a certain surface wave magnitude (Ms). The attenuation relationships were derived by using an iterative least squares fit procedure. These equations were derived from more basic concepts assuming that the intensity is proportional to the logarithm of seismic energy density at any location empirically. The isoseismal maps are elongated in the direction of local structural trend of causative faults. Therefore, attenuation relationships for the main direction of fault, transverse to it and average attenuation were derived. Ia = 11. 564 + 0. 943 M − 2. 508 Ln(Ra + 33) ,  ,  ,  ,  ,σ = 0. 79 ,  ,  ,  ,  ,  ,Ra <, 200 km along the main direction of fault Ib = 9. 469 + 0. 717 M − 2. 121 Ln(Rb +13) ,  ,  ,  ,  ,  ,σ = 0. 49 ,  ,  ,  ,  ,Rb<, 140 km transverse to the main direction of fault I =11. 926 + 0. 831 M − 2. 7 Ln(R + 22)  ,  ,  ,  ,  ,  ,  ,  ,σ = 0. 49 ,  ,  ,  ,  ,  ,  ,  ,R<, 167 km average attenuation Where M is the surface wave magnitude and I is the intensity at a distance R (km) from the epicenter. The attenuation of seismic intensity in Iran is faster than the East and West of China and Sicily and Calabria in Italy, apart from different tectonic characteristics of these regions.