Genetic programming-based attenuation relationship: An application of recent earthquakes in turkey

This study investigates an application of genetic programming (GP) for the prediction of peak ground acceleration (PGA) using strong-ground-motion data from Turkey. The input variables in the developed GP model are the average shear-wave velocity, earthquake source to site distance and earthquake magnitude, and the output is the PGA values. The proposed GP model is based on the most reliable database compiled for earthquakes in Turkey. The results show that the consistency between the observed PGA values and the predicted ones by the GP model yields relatively high correlation coefficients (R²=0.75). The proposed model is also compared with an existing attenuation relationship and found to be more accurate.     

Radiological characterization of Cay?rhan coal-fired power plant in Turkey

Natural radioactivity of Cay?rhan lignite coal treated at Cay?rhan (Ankara, Turkey) power plant, its ash and soil samples mixed with ash in the power plant field were investigated. For comparison, soil samples were collected from a distance of 4 km south of the plant. The analysis shows that the samples include natural radionuclides such as ²²⁶Ra, ²³²Th and ⁴⁰K. The mean activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K were 57.82, 30.45 and 322.21 Bq · kg⁻¹, respectively. Obtained values shows that the average radium equivalent activity (Ra_eq), air-absorbed dose rate (D), annual effective dose (AED) and external hazard index (H_ex) for all samples are 123.9 Bq · kg⁻¹, 58.90 nGy · h⁻¹, 71.99 μSv · y⁻¹ and 0.34, respectively. The Ra_eq values of samples are lower than the limit of 370 Bq · kg⁻¹, equivalent to a γ-dose of 1.5 mSv · y⁻¹. The measured activity concentrations for these radionuclides were compared with the reported data of other countries.     

Role of apoptosis in testicular tissue damage caused by varicocele

PURPOSE: During the last few years there has been an increasing interest in evaluating quality of life (QOL) data regarding surgical treatment. METHODS: The present study comments the efficacy of laparoscopic antireflux surgery after required Nissen fundoplication of 70 patients. Therefore, the German Gastrointestinal Quality of Life Index (GIQLI) was used to query the patients preoperatively and three times after surgery up to 1 year. RESULTS: Preoperatively, we found a low general GIQLI score (mean 92.7 points), which increased 6 weeks postoperatively (116.8 points), 3 months (124.8) and 1 year (mean 123.9 points) significantly and is now comparable to the healthy population (122.6 points). CONCLUSION: It is our opinion that the efficacy of the treatment of gastroesophageal reflux disease with required Nissen fundoplication can also be documented and discussed by using QOL.     

Gamma ray and neutron shielding properties of some concrete materials

Shielding of gamma-rays and neutrons by 12 concrete samples with and without mineral additives has been studied. The total mass attenuation and linear attenuation coefficients, half-value thicknesses, effective atomic numbers, effective electron densities and atomic cross-sections at photons energies of 59.5 and 661 keV have been measured and calculated. The measured and calculated values were compared and a reasonable agreement has been observed. Also the recorded values showed a change with energy and composition of the concrete samples. In addition, neutron shielding has been treated in terms of macroscopic removal cross-section (Σ_R, cm⁻¹) concept. The WinXCom and NXcom programs were employed to calculate the attenuation coefficients of gamma-rays and neutrons, respectively.     

The Small and Silent Force Multiplier: A Swarm UAV—Electronic Attack

At the last two decades, according to UAVs concepts and technological advances, there have been lots of unimagined improvements. Nowadays there are serious works and researches about the usage of UAVs in military operations at electronic warfare (EW) missions. But most of the work on UAV platforms is based upon the advantages of a single, big, expensive, and non-expendable platform. In this study, to get rid off the disadvantages of a stand alone platform a new concept is developed consisting of multiple UAVs with smaller dimensions, at a cheaper price and a wider coverage. According to clarify the study, firstly the EW and RADAR systems and then the swarm UAV concepts are explained. In this manner the current and previous works are pointed out and then the use of the swarm UAVs for EA in military operations is stated. Objectively, the swarm UAV concept’s advantages and some outstanding challenges to the intra-theater space have been put forward regarding the information mentioned above. As a result it is considered that the swarm UAV systems will be tasked important EW missions in the future operation theatres, as soon as the technical handicaps are solved.     

Chemical composition of building materials used in Turkey

The main goal of this work was to determine the chemical composition of building materials used in Turkey by utilizing energy dispersive X-ray fluorescence (EDXRF) spectrometry. Gas concrete, cement, sand, bricks, roofing tiles, marble, lime and gypsum materials were selected as building materials for this research. The chemical contents and their trace concentrations of the selected samples were determined. The most abundant oxides measured were generally SiO₂, Al₂O₃, CaO, MgO, Fe₂O₃, K₂O and SO₃ for all samples. While the main chemical component of gas concrete, cement, sand and marble samples were SiO₂ and CaO, brick and roofing tile mainly consisted of SiO₂ and Al₂O₃. CaO and SO₃ were major component of lime and gypsum samples, respectively. For U and Th concentrations in the samples, activities of ²²⁶Ra and ²³²Th were measured by utilizing gamma spectrometry. ANOVA and Pearson correlation analyses were performed on the studied data for statistical analysis.     

Natural and artificial radioactivity measurements in Eastern Black Sea region of Turkey

In the present work, naturally occurring radionuclides of ²²⁶Ra, ²³²Th and ⁴⁰K were measured in soil samples collected from the Eastern Black Sea region of Turkey. It was found that the activity concentrations ranged from 12 to 120 Bq kg⁻¹ for ²²⁶Ra, from 13 to 121 Bq kg⁻¹ for ²³²Th and from 204 to 1295 Bq kg⁻¹ for ⁴⁰K. Besides naturally occurring radionuclides, ¹³⁷Cs activity concentration was measured in soil, lichen and moss samples and it was found that ¹³⁷Cs activity concentration ranged from 27 to 775 Bq kg⁻¹ with for soil, from 29 to 879 Bq kg⁻¹ for lichen and from 67 to 1396 Bq kg⁻¹ for moss samples. Annual effective doses due to the naturally occurring radionuclides and ¹³⁷Cs were estimated. Ecological half-lives of ¹³⁷Cs in lichen and moss species were estimated. The decrease of the activity concentrations in the present measurements (2007) relative to those in 1993 indicated ecological half-lives between 1.36 and 2.96 years for lichen and between 1.35 and 2.85 years for moss species.