In this paper, using simulation code CRPropa3. 0, the propagation of 104 primary cosmic rays of proton and iron with energy range of 1018 to 1021 eV was simulated. The spectra of the secondary photons and electron-positrons generated in the interactions of Ultra-high energy cosmic rays (UHECRs) with cosmic background photons were investigated. The photon and electron spectra considered here are generated in photopion production, beta decay, and pair production. The minimum energy of primaries and the spectral index of source injection is changed separately and the effect of these changes on the spectra is investigated. Also, the total primary energy percent which transfers to secondaries, is calculated. It is found that for both primaries, lowering the minimum energy of the primaries leads to the decrease of the flux of secondaries. This also results in the decrease of the total energy percent carried by beta and photopion products and the increase of the energy percent of pair production. Finally, in is shown that by increasing the spectral index, the flux and the energy percent of all secondaries decreases for proton and iron primaries.

Muon-electron ratio and median zenith angle of Extensive Air Shower (EAS) is calculated for the energy range of 1019 to bigger than 1020 eV. The results are compared with the simulation work of Capdevielle et al. The results show a good correspondence with proton primary composition up to energy level of 7×1019 eV. In higher energies above GZK cut off, a considerable increase is calculated in cosmic primary photons. In addition, event frequency distribution above energy 7×1019 eV shows increasing concentration towards super galactic plane.

The first phase of the Alborz Observatory Array (Alborz-1) consists of 20 plastic scintillation detectors each one with surface area of 0. 25 spread over an area of realized to the study of Extensive Air Showers around the knee at the Sharif University of Technology campus. The first stage of the project including construction and operation of a prototype system has now been completed and the electronics that will be used in the array instrument has been tested under field conditions. In order to achieve a realistic estimate of the array performance, a large number of simulated CORSIKA showers have been used. In the present work, theoretical results obtained in the study of different array layouts and trigger conditions are described. Using Monte Carlo simulations of showers the rate of detected events per day and the trigger probability functions, i. e., the probability for an extensive air shower to trigger a ground based array as a function of the shower core distance to the center of array are presented for energies above 1 TeV and zenith angles up to. Moreover, the angular resolution of the Alborz-1 array is obtained. For experimental study of the array, Alborz-1 sub-array consists of 5 detectors on a pentagon configuration similar to the central cluster of the Alborz-1 array have been collecting data since 2014 February for 14 month in 4th floor of physics department at Sharif University of Technology. Alborz-I, made of 20 scintillation detectors is set up in a cluster layout to study the cosmic ray spectrum in the energy range of 1012 to 1016 eV. . This paper reveals the zenith angle distribution function of detected air showers by this sub-array.

The amount of cosmic rays varies widely with the altitude, latitude and longitude in each region. In this study, the radiation doses due to the cosmic rays were estimated in two steps: in the first step, the neutron and gamma components of the radiation dose were measured for a roundtrip flight on 3 flight routes (Shiraz-Asaluye, Asaluye-Rasht and Shiraz-Mashhad) using a gamma-tracer photon detector and a Thyac 190N, neutron detector. The minimum values of the measured gamma and neutron doses of 0.15 and 0.04 mSv were measured on the Asaluyeh-Shiraz route at the lowest altitude of 19000 ft, while for Rasht-Asaluyeh route at an altitude of 35000ft those values were found to be 2.52 and 1.09mSv, respectively. In the second step, a number of aircrew members were equipped with thermoluminescence dosimeters (TLD cards) for evaluating the gamma dose and polycarbonate dosimeters (SSNTD) for assessing the neutron dose for one year. The measured value of the annual effective dose received by the crew ranged between 0.5 mSv/y and 1.16 mSv/y, with an average of 0.9 mSv/y for the gamma component and between 0.37 mSv/y and 0.77 mSv/y with an average of 0.61 mSv/y for the neutron component. The results of this investigation are comparable with the investigations that have been conducted in other countries. For instance in UK, the reported annual effective dose of aircrew is about 2mSv, and in Canada, it is estimated to be between 1 to 5mSv, depending on the flight situations (such as the latitude and longitude of the cities, the flight altitude, etc).

In this study, we consider the effects of the cosmic rays and the magnetic diffusion on the thermal instability in the interstellar mediums. The dynamical effect as well as the heating effect of the cosmic rays are investigated on the thermal condensation in a medium where the cosmic rays diffuse along the magnetic field lines and the magnetic diffusion is present. Two separate profiles, i.e. constant field and force-free field, are considered for the magnetic field of the medium background. The linear perturbation analysis is used for the study of the thermal instability in a medium with a point of view on the previous works. The results show that the cosmic rays reduce the growth rate of the magnetothermal condensation mode, and increase the domains of stability. However, the magnetic diffusion shows two different behaviors which depend on a number of conditions affecting the magnetic diffusivity. In other words, the magnetic diffusion increases the domains of stability for cases less than a certain value of magnetic diffusivity, and decrease the domains of stability for cases larger than this certain value. Furthermore, we found that the dynamical effect of the magnetic diffusion dominates the dynamical effect of the cosmic rays. Finally, the results address some regions in which the fragmentation of the clouds into clumps and cores can be seen with the magnetothermal condensation effects.

Considering the spectral energy of the observed cosmic rays in the earth and using a propagational model of these rays, the minimum required energy for production of these rays in the center of galaxy studied. Assuming an equation for the time scope from the galaxy and a relation for their diffusion, calculations show that the central part of the galaxy, the most energetic part of the galaxy, does not have the necessary conditions to produce all these rays. But the centre of the galaxy has the possibility to produce energy range between 3*1015to4*1018eV.The spectral energy of this energy is suggested to be BE-2.9cm-2s-1sr-1eV-1.

Extensive Air Showers (EAS), initiated by Ultra-high-energy cosmic rays (UHECRs), generate geo-synchrotron and geo-magnetic radiations and they are, also, the source of excess charge processes. In the frequency range of 10 to 100 MHz, coherent radiation is formed. Many experiments use the radio detection technique for studying EAS features. The Auger Engineering Radio Array (AERA), part of the Pierre Auger Observatory, uses hundreds of radio antennas working in the frequency range of 30 to 80 MHz to support the investigation of UHECRs together with the standard surface and fluorescence detectors. The AERA radio frequency range is significantly contaminated by the human-made and usually narrow-band Radio Frequency Interference (RFI), e. g., shortwave radio transmitters. The presence of RFIs in the detected signals increases the ratio of spurious triggers,in consequence, empty data in ate the databases. This study proposes replacing the currently used IIR-notch nonadaptive , filter by the delayed version of the wellknown Least Mean Squares (LMS) algorithm, which offers crucial advantage adjustment. The current study implemented 32/64-stage Delay Least Mean Squares (DLMS) , filters on cost-effective Cyclone®,IV and Cyclone®,V as non-canonical Finite Input Response (FIR) with a sufficient safety margin for a global clock being at least 20% higher than 200 MHz, which equals the ADC sampling frequency.

It has previously been reported that differences in life expectancy can be linked to income. In Norway, a registry-based study that included all Norwegian residents aged ≥,40 years (2005-2015) was performed. This study showed substantial and increasing gaps in life expectancy by income level during the interval between 2005-2015. Compared to the United States, the largest life expectancy differences were for individuals in the lower to middle part of the income distribution, although differences were observed at all income levels. Despite its undeniable strengths and although this paper can be considered as a significant contribution to this field, it has some shortcomings. The first shortcoming of this study is due to ignoring the effects of population exposures to natural and man-made ionizing and non-ionizing radiation on life expectancy. Another shortcoming arises from ignoring the strong impact of education on lifestyle. In summary, what is observed in this study might be at least to some extent, due to education-related changes in lifestyle and not necessarily income (despite the mutual links between education and income).

The energy spectrum of cosmic rays exhibits a power-law distribution, meaning there are more particles at lower energies and fewer particles at higher energies. There is a feature known as the knee at about 3×1015eV in the energy spectrum of cosmic rays, and there is another feature called the ankle at about 1018eV. There are several models to explain the knee and ankle features in the energy spectrum of cosmic rays, such as, shock acceleration model, which suggests that the knee may be arise from the maximum energy that can be achieved through shock waves produced by supernova explosions, extragalactic sources model, which suggests that the ankle may be arise from the extremely energetic astrophysical sources outside our galaxy, and the propagation models, that we focus on in this research. cosmic ray propagation has usually been assumed to be in a form of normal diffusion, which is a diffusion process with a linear relationship to time. But, in anomalous diffusion, the mean squared displacement of a particle has a non-linear relationship to time. In this research, we investigate the propagation of cosmic rays in the galactic medium. First, we simulate the trajectory of cosmic rays with the energy of 1017eV from the galactic center in two models of diffusion to show the differences between propagation in the homogeneous and fractal galactic medium. Simulations show that cosmic ray propagation in the galactic medium gives a greater galactic residence time and energy density for normal diffusion particles compared to anomalous diffusion particles. Here, the program, that is applied in this research, presents the results of a simulation using a model of the galactic magnetic field appropriate to the related medium. It uses the technique described in Clay et al. (2000) and Clay (2002). Normal cosmic ray diffusion assumes very simple properties of the structure of cosmic magnetic fields. A better approximation is to assume that the magnetic structure has fractal properties when modelling the propagation. Later, residence times of cosmic rays on a wide range of energy spectrum in the anomalous diffusion model are found. Results can correspond to Lagutin’s point of view saying that the “knee” in the cosmic ray spectrum is the consequence of anomalous diffusion of the particles in the fractal galactic medium (Lagutin et al., 2001b). In other words, the “knee” may be caused by the extensive distances that cosmic ray particles can travel between inhomogeneities of magnetic fields and from the fact that a particle stays in a magnetic trap for a long time. Our study is useful for understanding the possibility that some spectral features (the knee and the ankle) of the spectrum of cosmic rays observed at the Earth are induced by the fractal nature of the galactic medium.