Sharif Digital Repository

There are several methods for identifying unknown elements of an unknown compound. One of the common methods for this purpose, using neutron activation analysis. In conjunction with this method, different computer codes and softwares have been developed and used. One of these methods is K0 method that is a single comparator method. The code that based on this method is K0-IAEA code that is written by the International Atomic Energy Agency and access to it is free. Foremost objective of this study is to determine how to work with this code. In order to evaluate the accuracy of the results of the code, examples have taken into consideration the amount of time previously unknown elements by... 

Total air particulate matter of the city of Isfahan has been measured for elemental characterization in four principal directions of the city and during the year 2007-2008. High volume air samplers using whatman 41 filters have been utilized and instrumental neutron activation analysis has been used as the analytical method. Twenty one elements arising from seasonal and geographical distributions of the various elements have been determined. These distribution patterns have been discussed in view of the prevailing wind direction, location of the industrial facilities, and the Pearson correlation coefficients  

Dust phenomenon is a combination of tiny particle with urban pollution that it is harmful for respiratory disease. But this phenomenon has been prevalent in our country recently. We utilized NASA satellite pictures to observe dust storms in the present project. We have collected images of possible sources of dust on the days when we are faced with the dust storm phenomenon. Then by processing of NASA satellite pictures (recognition of distribution of optical and particle density in the dust particle arising and comparing results through analysis of these images to estimate the main characteristics of the sampling locations). we have find the desired location for taking samples of soil... 

City of Karaj with 2 million population used to enjoy very clean and accommodating air and environment . This congenial condition was due to agricultural and gardening activities of the local population . This way of life has undergone a profound change due to a change in the economic activities of the local population from farming and agriculture to industrial activities . And this has brought particulate matter wich has been exacerbated in the recent years . With the additional onslaught of the dust storms coming from the neighboring countries due to drying up of rivers and lagoons .The main object of this work was to obtain the spectrum of the PM and the additional component of PM that... 

Environmental conditions of various cities of Iran are deteriorating due to various contributing effects of increased traffic, deforestation, industrial pollution etc. Arak is an example in point. It is a city of about 440,000 inhabitants. It is located at the edge of the main central desert (Kavir) of Iran. It lacks any appreciable vegetation or wooded areas and it is the home of a number of major industries. These include aluminum smelting, petrochemical industry, refinery, power plant and various other heavy manufacturing facilities. It was suggested to perform an air sampling of the city for a whole year (2010-2011) to determine the concentration of various elements by instrumental... 

Method of Prompt Gamma Neutron Activation Analysis (PGNAA) is useful for controlling some massive production processes such as cement industry and mineral materials. Difficulty of other methods of analysis such as XRF comparing with PGNAA is that mass of sample is small and it doesn’t determine heterogeneity of mixture. On the other hand, need to sampling is also another problem of these analysis methods because sampling is terminated and it doesn’t supervise on production continuously, in fact its quality can’t be revealed simultaneously and there is a long time between sampling and control of process. Usually, analysis methods such as XRF are useful for processes that are controlled... 

Ahwaz is typical of a polluted city. It ranks in the third place after Tehran and Esfahan and with the onslaught Of the dust storms it has acquired the dubious distinction of 1st polluted city in the world. The pollution status of this city was investigated from May 2012 to May 2013. 110 air filters were collected during this period. The air filters were analysed with AAS and INAA techniques. with the use of AAS we measured the concentration of Cd, Cu, Fe, Mg, Mn, Ni and Pb elements. For the use of INAA method on the air filters we used two reactors of MNSR at Esfahan and the 5MW research reactor of Tehran. We managed to measure twenty five elements of Al , As , Br , Ca , Ce , Cl , Co , Cr ,... 

In this study, the emission and detection of secondary particles such as gamma and neutron along the beam path was investigated to evaluate proton range during treatment. Simulations and detections were performed by Geant4 toolkit that was developed base on Monte Carlo method. First, a mono-energetic proton beams irradiated a homogeneous water phantom. Then the factors influencing the accuracy of beam range estimation have been investigated and finally proton beam range was evaluated by simulation the human eye phantom. According to the results, the accuracy of range verification by prompt gamma is very high, about 1 mm. In phantoms with more oxygen in their composition, the percentage of... 

Scintillation detectors are categorized as low energy resolution detectors in the classification of energy-sensitive detectors. The presence of broad peaks in the gamma-ray spectra of these detectors increases the overlapping probability of photopeaks of different isotopes and makes it extremely difficult to identify the spectra. The common method for identifying and quantifying of elements in a sample using nuclear spectroscopy is to use photopeak counts obtained with high-energy resolution detectors such as semiconductor detectors. To deal with the low energy resolution of scintillation detectors in quantitative analysis, the whole information of gamma-ray spectra is used instead of using... 

The main purpose of this research is to select a suitable solution for regeneration of ion exchange resins of TR system of Bushehr nuclear power plant and also to compare and evaluate the possibility of using industrial cationic resin (Amberlite IR120) instead of nuclear grade cationic resin (Amberlite IRN97).First, different solutions for regeneration of cationic resins were investigated. For this purpose, three strong acids including hydrochloric acid (HCl), sulfuric acid (H2SO4) and nitric acid (HNO3) were selected and each of these acids was tested in two different concentrations and two different linear velocities; Also, to evaluate the appropriate solution for anionic resin... 

Neutron activation is a nuclear method for determination of elements in each sample. In this method, the samples are exposed to neutron irradiation by neutrons which are usually produced by research reactor, and then the core becomes unstable due to capturing the neutron and emits gamma rays. The emitted gamma rays can be detected by a detector like a HPGe semiconductor which has a high resolution. All nucleuses have a probability of neutron absorption, expressed by the absorption cross section area. The radioactive nuclei value depends on the nuclear half-life and the number of unstable nuclei. The only Windows environment commercial software for neutron activation analysis was K0 for... 

Generating the experimental spectrum for all gamma-ray elements is difficult and practically impossible in some industrial applications. Furthermore, in many applications such as neutron activation, it is not possible to obtain an experimental spectrum for a single isotope on account of the fact that the gamma-ray spectrum obtained from neutron activation is derived from the gamma-rays of various elements in a sample. Therefore, using computational techniques like Monte Carlo method for calculating the detector response functions seems an appropriate solution. The detector response functions for 3''×3'' NaI detectors have been simulated using MCNPX 2.7 code and Ptrac card in this project....