Mahmut Doğru

Artificial neural network model for earthquake prediction with radon monitoring

Apart from the linear monitoring studies concerning the relationship between radon and earthquake, an artificial neural networks (ANNs) model approach is presented starting out from non-linear changes of the eight different parameters during the earthquake occurrence. A three-layer Levenberg-Marquardt feedforward learning algorithm is used to model the earthquake prediction process in the East Anatolian Fault System (EAFS). The proposed ANN system employs individual training strategy with fixed-weight and supervised models leading to estimations. The average relative error between the magnitudes of the earthquakes acquired by ANN and measured data is about 2.3%. The relative error between the test and earthquake data varies between 0% and 12%. In addition, the factor analysis was applied on all data and the model output values to see the statistical variation. The total variance of 80.18% was explained with four factors by this analysis. Consequently, it can be concluded that ANN approach is a potential alternative to other models with complex mathematical operations.

Iso-radioactivity curves of the water of the Hazar Lake, Elazig, Turkey

Alpha and beta radioactivity concentrations have been determined in the Hazar Lake (East of Turkey) surface, middle and bottom water. The total alpha-radioactivity concentration in the surface, middle and bottom levels varies from 0.32 to 2.52 Bq/l, from 0.21 to 2.70 Bq/l and from 0.12 to 0.96 Bq/l, respectively. The beta-radioactivity concentration in the surface, middle and bottom water levels varies from 0.01 to 0.16 Bq/l, from 0.01 to 0.27 Bq/l and from 0.03 to 0.23 Bq/l, respectively. The iso-radioactivity curves were drawn from the obtained data during 1998–2001.

Measurements of radioactivity and dose assessments in some building materials in Bitlis, Turkey.

In this study, samples of perlite, pumice and Ahlat stones (Ignimbrite) extracted from mines in Bitlis and samples of other building materials produced in facilities in Bitlis were collected and analyzed. Activity concentrations of (226)Ra, (232)Th and (40)K in samples of building materials were measured using NaI detector (NaI(Tl)) with an efficiency of 24%. The radon measurements of building material samples were determined using CR-39 nuclear track detectors. (226)Ra, (232)Th and (40)K radioactivity concentrations ranged from (29.6±5.9 to 228.2±38.1Bq/kg), (10.8±5.4 to 95.5±26.1Bq/kg) and (249.3±124.7 to 2580.1±266.9Bq/kg), respectively. Radon concentration, radium equivalent activities, absorbed dose rate, excess lifetime cancer risk and the values of hazard indices were calculated for the measured samples to assess the radiation hazards arising from using those materials in the construction of dwellings. Radon concentration ranged between 89.2±12.0Bq/m(3) and 1141.0±225.0Bq/m(3). It was determined that Raeq values of samples conformed to world standards except for perlite and single samples of brick and Ahlat stone. Calculated values of absorbed dose rate ranged from 81.3±20.5 to 420.6±42.8nGy/h. ELCR values ranged from (1.8±0.3)×10(-3) to (9.0±1.0)×10(-3). All samples had ELCR values higher than the world average. The values of Hin and Hex varied from 0.35±0.11 to 1.78±0.18 and from 0.37±0.09 to 1.17±0.13, respectively. The results were compared with standard radioactivity values determined by international organizations and with similar studies. There would be a radiation risk for people living in buildings made of perlite, Ahlat-1 and Brick-3.

Measurement of gross alpha and gross beta activity concentrations in human tooth

The gross alpha and gross beta activity concentrations were measured in human tooth taken from 3 to 6 age-groups to 40 and over ones. Accumulated teeth samples are investigated in two groups as under and above 18 years. The gross alpha and beta radioactivity of human tooth samples was measured by using a gas-flow proportional counter (PIC-MPC 9604-alpha/beta counter). In tooth samples, for female age-groups, the obtained results show that the mean gross alpha and gross beta activity concentrations varied between 0.534-0.203 and 0.010-0.453 Bq g(-1) and the same concentrations for male age-groups varied between 0.009-1.168 and 0.071-0.204 Bq g(-1), respectively.

The Possible Contribution Of 129i In The Drinking Water And Food Supply To The Nodular Formation Of Thyroid Tissue

Nodular formation of the thyroid tissue can occur as a result of exposure to radiation. The nodular goiter is a common disease seen in the city of Elazig and its surroundings, in the eastern part of Turkey. A prospective study was conducted in an effort to identify the role of 129I in drinking water supply. Specimens obtained from nodular and normal thyroid tissue during surgery and also water specimens were counted by nuclear spectrometric system. 129I radioactivity in nodular tissue was noted to be higher compared to normal tissue and the difference was statistically significant (p < 0.05). There was no statistically significant difference (p > 0.05) between 129I radioactivity in the water supply and tissue obtained from the patients who have malignant or benign nodular lesions. These results support that the 129I radioactivity level in the water supply is one of the risk factors of the nodular formation of the thyroid tissue in the eastern part of Turkey.

Measurement of Radon Concentration in Different Construced Houses and Terrestrial Gamma Radiation in Elazig, Turkey

Abstract In this study, we have measured the terrestrial γ-radiation in the Elazig, which is the eastern city of Turkey by using portable Nal γ-ray detector. The measurements were performed in 21 critical places to determine the variation of the gamma radiation level in air in the city. The γ-radiation levels were found to be between 38.1 pGy/s and 55.7 pGy/s. We have also measured indoor radon (222Rn) concentration in different constructed houses of the city by using CR-39 passive radon detector. The detectors were obtained from the Cekmece Nuclear Research and Training Centre laboratory and they remained for five months in selected houses rooms. All detectors were evaluated and etched in the same laboratory. The obtained results were interpreted according to the house constructions and the geologic formation of the soil.

Radioactivity analysis of soil samples taken from the western and northern shores of Lake Van, Turkey

In this study, concentrations of the radioactive isotopes 226Ra, 232Th, 40K and 137Cs were measured in soil samples from the shores of Lake Van using a high purity germanium detector. Activity concentrations obtained for these nuclides were compared with world average values. The average 226Ra, 232Th and 40K activity concentrations calculated for the soil samples were higher than the world average values reported by UNSCEAR. The lowest 226Ra, 232Th and 40K activity concentrations were recorded in sample T-1 whereas the highest values were recorded in sample T-11. Concentrations of 137C in the samples ranged between 0.91 ± 0.01 and 29.68 ± 0.33Bqkg-1. In order to evaluate the radiological hazards resulting from natural radioactivity, radium equivalent activities, absorbed dose rates, and internal and external hazard indices were calculated and the results were compared with internationally recognized values.

The Statistical Analysis of the Radioactivity Concentration of the Water Data in Malatya City, Turkey

Abstract The natural radioactivity data of 306 water samples, which were obtained from various 51 sampling points of Malatya that is the eastern city of Turkey, was studied by applying the factor and cluster statistical analysis to interpretation and determination of the general radioactivity in the city. The obtained data from the statistical analysis were evaluated according to the geological formation of the state. The varimax factor rotation was applied to the data. Two factors were extracted from the radioactivity of the water supplies, tap water, and water depots data, which account for about 95.52% of the total variance. Factor 1 and factor 2 explained 48.5% and 47% of the variance, respectively.