Investigation of natural and artificial radioactivity levels in travertines of the Cappadocia region in Turkey

This study determined natural and artificial radionuclide concentrations to evaluate natural radioactivity and health risk levels of nine travertines in the Yaprakhisar and Balkayası regions in Turkey. The samples coded B1-M, B2, B5, B7, B8, and B10 represent waste derived from the Yaprakhisar travertines, as well as samples T5-M, T12, and Z1 travertines derived from Balkayası. The levels of natural and artificial radionuclide concentrations (232Th, 40K, and 137Cs) were measured using a high-purity germanium (HpGe) detector system. The travertine activity ranged from 2.09 to 12.07 Bq kg-1 for 232Th, 4.21 to 13.41 Bq kg-1 for 40K, and 0.42-3.26 Bq kg-1 for 137Cs. The results showed that the activity concentration values for 232Th, 40K, and 137Cs were coherent with the travertine analysis results in the UNSCEAR, 2000; 2008 publications. The values obtained were lower than the average values in the UNSEAR reports. The radiological hazard parameters calculated in this study were absorbed gamma dose rate (D), radium equivalent activity (Raeq), annual gonadal dose equivalent (AGDE), exposure dose (ER), total annual effective dose (AEDEtotal), excess lifetime cancer risk (ELCRtotal), gamma representative level (GRL), internal hazard index (Hin) and external hazard index (Hex).

Recent results for the one-proton transfer reaction in the 18O+48Ti collision at 275 MeV

The 18O+48Ti reaction was studied at the energy of 275 MeV for the first time under the NUMEN and NURE experimental campaigns with the aim to investigate the complete net of reaction channels potentially involved in the 48Ca→48Ti double charge exchange transition. Such a transition is of great interest because of its relevance to the extraction of 48Ca→48Ti double beta decay nuclear matrix element. The relevant experiment was carried out at the MAGNEX facility of INFN-LNS in Catania. Angular distribution measurements for the various reaction products were performed by using the MAGNEX large acceptance magnetic spectrometer. The present contribution is focused on the analysis of the one-proton transfer channel with emphasis on the particle identification technique and the estimation of background contaminations.

Determination of self-attenuation correction factor for lichen samples by using gamma-ray spectrometry

In this study, we determine the self attenuation correction factor for lichen samples collected from Erzurum, a city located in the eastern region of Turkey by using gamma-ray spectrometry. The self attenuation correction factor is calculated for 17 lichen samples with densities ranging from 0.683 g/cm3 to 0.886 g/cm3. The transmission method has been used to obtain self-attenuation correction factors. Self attenuation correction factor versus energy fit curve is presented. It is observed that self attenuation correction factor changes with density. At lower energies the self-attenuation correction factor has higher values. At higher energies it has smaller values and tends to become stable.

Determination of activity concentration of natural and artificial radionuclides in sand samples from mediterranean coast of Antalya in Turkey

In this paper, we attempt to determine the activity concentration of natural and artificial radionuclides in 37 sand samples from the Mediterranean coast of Antalya in Turkey by using a high purity Germanium (HpGe) detector. 238U, 232Th, 40K and 137Cs activity concentrations, absorbed dose rate, annual effective dose equivalent, radium equivalent activity, external and internal hazard index of sand samples are determined res-pectively. The average values are 13.43 ± 0.21 Bq/kg, 6.96 ± 0.06 Bq/kg and, 122.46 ± 18.58 Bq/kg, for 238U, 232Th and 40K respectively. Most of the activity concentration values are less than below minimum detection limit for 137Cs. The average values of the absorbed dose rate D (nGy/h), annual effective dose equivalent AEDE(μSv/y), radium equivalent activity Raeq (Bq/kg), external hazard index Hex and internal hazard index Hin are 15.52 nGy/h, 19.03 μSv/y, 32.81 Bq/kg, 0.09 and 0.12 respectively. It is observed that 238U, 232Th, 40K and 137Cs activity concentrations, absorbed dose rate, annual effective dose equivalent, radium equivalent activity are in the limit of the published values, external and internal hazard index values are less than unity.

Retrograde continuous warm blood cardioplegia: maintenance of myocardial homeostasis in humans

Recent clinical reports have suggested that continuous delivery of oxygenated warm blood cardioplegia through the coronary veins (retrograde cardioplegia) produces good myocardial preservation during aortic cross-clamping. No data exist, however, about actual myocardial metabolism/homeostasis during retrograde warm blood cardioplegia. We studied 100 consecutive patients undergoing coronary artery bypass grafting, aortic valve replacement, or both who received retrograde continuous warm blood cardioplegia (4:1 dilution) during aortic cross-clamping for 54 to 174 minutes. We measured pH, oxygen tension, carbon dioxide tension, HCO3, base excess, and oxygen content of the inflow cardioplegia and the blood egressing from coronary arteries during each arteriotomy for bypass grafting (arteries act as postcapillary veins with retrograde cardioplegia) or the left and right coronary orifices during aortic valve replacement. We also measured these variables from the coronary sinus effluent 1 minute after release of the aortic cross-clamp. Retrograde cardioplegia flow ranged from 50 to 250 mL/min (mean flow, 150 mL/min). All patients were maintained at normothermia during bypass. A total of 460 samples were analyzed (4.6 per patient). Neither the duration of aortic cross-clamping nor the artery sampled affected myocardial blood gases. The pH dropped from 7.41 +/- 0.05 for the inflow cardioplegia to 7.32 +/- 0.1 when sampled from coronary arteries, and the oxygen tension fell from 181 +/- 25 to 28 +/- 5 mm Hg, respectively. Carbon dioxide tension rose from 31.0 +/- 4.1 to 41.4 +/- 9.8 mm Hg. Coronary sinus blood gases 1 minute after cross-clamp removal showed no acidosis or oxygen debt.(ABSTRACT TRUNCATED AT 250 WORDS)