Band 111, Heft 2

Cross sections of the 86 Sr(p,3n) 84m Y, 86 Sr(p,αn) 82m Rb, and 86 Sr(p,x) 85g Sr reactions were measured from their respective thresholds up to 16.2 MeV and from 23.0 to 44.1 MeV at FZJ, and from 14.3 to 24.5 MeV at LBNL, using 96.4% enriched 86 SrCO 3 as target material. Thin targets prepared by sedimentation were irradiated with protons in a stacked-form, and the induced radioactivity was measured by high-resolution γ-ray spectrometry. Nuclear model calculations based on the code TALYS reproduced our experimental cross section data well. From the excitation functions, the integral yields of the above three radionuclides were calculated. The yield of 85g Sr via the nat Sr(n,γ) process was also measured using the TRIGA Mark-II reactor at AERE, Savar. A comparison of the reactor and cyclotron production of carrier-added 85g Sr is given. The production possibilities of the three investigated radionuclides in no-carrier-added forms at a 30 MeV cyclotron via new routes are discussed.

Uranium removal from wet phosphoric acid is a vital process for food and environmental security. The incorporation of thiourea-formaldehyde into the kaolinite networks was performed to obtain an effective and acid-resistant sorbent. The prepared composite was applied for U(VI) uptake from crude phosphoric acid. X-ray diffraction, EDX, scanning electron microscopy, and Fourier transform infrared analyses were carried out to explore the properties of the yield composite. The sorption characteristics, i.e., capacity, kinetic, isotherm, and thermodynamic were investigated. The anticipated data declare that the reaction is fast whereas 60 min is sufficient to reach the equilibrium state. The experimental results obeyed to Pseudo second-order kinetic model and Langmuir isotherm model. The maximum sorption capacity was about 5.8 mg g −1 . Thermodynamic parameters displayed that the sorption process is endothermic, feasible, and spontaneous. The displayed results demonstrate that the prepared composite could be used as the proper material for producing eco-friendly fertilizers.

The removal of hazardous metal ions from liquid waste effluents is very important for water as well as environmental safety. In this regard, this article discusses in detail the U(VI) uptake from aquatic environment using biomass-based Soya Bean activated carbon (labeled as AC-SB). XRD, SEM, FTIR, Raman, and BET analysis were used to characterize the synthesized AC-SB sorbent. Batch-type experiments were used to investigate the effect of various parameters on adsorption efficiency, including pH, metal-ion concentration, temperature, and contact time. The sorption experimental data have been described well with pseudo-second-order kinetic mathematical equations. The equilibrium state of the uptake reaction was 120 min. The Langmuir isotherm model accurately described the equilibrium process which declares that the uranium sorption is a monolayer and homogeneous process. The sorption capacity of the prepared AC was 32.7 mg g −1 . Thermodynamic analysis explore that the U(VI) uptake process is endothermic, feasible and spontenous process. The displayed results demonstrate that the prepared AC-SB sorbent could be used as the proper material for uranium sorption from real matrix samples.

In this study, graphene oxide and aginate were used to synthesis of nanobiocomposites under different synthesis conditions and the used to investigate the adsorption properties of Th (IV) ions from aqueous solutions. BET surface area, SEM and TEM images, FT-IR spectrometry, XRD techniques were used for the characterization of the adsorbents. In batch adsorption experiments, parameters affecting the adsorption efficiency such as solution pH, contact time, Th (IV) concentration and temperature were investigated using central composite design (CCD). ANOVA (analysis) analysis at the 95% confidence interval of the model applied for the experimental design and the compatibility of this model with the experimental findings were examined. The relevance of the model for the nanobiocomposite prepared by the 1st method is that the P value is <0.05 and the model F value is 23.77 and 39.45 with the 2nd method, respectively. These results show that the regression for this method is statistically high. The correlation coefficient ( R 2 ), which was 95.69% for the 1st method and 97.36% for the 2nd method, indicates a high coordination between the observed values and the estimated values. According to the CCD results, it has been observed that the main effects of the adsorption process with the materials obtained by the 1st method are in the direction of increasing the concentration, while pH, time and temperature do not have a statistically significant effect. In the adsorption process with the materials obtained by the 2nd method, it was observed that the concentration, time and temperature caused an increasing effect. Langmuir, Freundlich and Dubinin–Radushkevich isotherms were used to determine the adsorption model and the constants related to these isotherms were calculated. In addition, the adsorption process was also investigated in terms of thermodynamics.

Fluoride toothpastes have made a significant contribution towards oral hygiene. This study proposes instrumental neutron activation analysis (INAA) as a suitable technique for determining fluorine in toothpastes. The method involved a 10 s irradiation, followed by 10–20 s decay, and counting for 10 s, using a pneumatic system and high purity germanium detector. All irradiations were performed at miniature neutron source reactor with thermal neutron flux 1 × 10 12  cm −2  s −1 . Since Na was present in all toothpastes, the quantification of fluorine required correction for 23 Na( n ,α) 20 F threshold reaction. Fluorine determination was validated by analysing the samples by ion chromatography. All toothpastes were also analysed for other elements by k 0 -INAA and ICP-OES. Both techniques quantified 28 elements including Al, As, Ba, Ca, Ce, Cl, Co, Cr, Cu, F, Fe, Hf, K, La, Mg, Mn, Na, P, S, Sb, Sc, Si, Sm, Sn, Sr, Ta, Ti and Zn. This study, categorized toothpastes in five groups based on concentrations of Ca, P and Ti.

3D printer technology has recently become easily reachable technology and are used to create simple or complex structures with high-quality. Its superior advantages could also be useful on the production of effective radiation shielding materials. On this purpose, the presented work studies the gamma and neutron shielding effectiveness of Acrylonitrile Butadiene Styrene (ABS) sample, a 3D printing material, reinforced with Bi and TiO 2 nanopowders at various gamma and neutron energies. The gamma shielding properties were evaluated using experimental (High Purity Germanium detector system), theoretical (WinXCOM computer program) and simulation techniques (GEANT4 and FLUKA) in a wide gamma energy region ranging from 59.5 to 1332.5 keV. The investigation on neutron attenuation capabilities of the printed composites were performed with help of simulation and theoretical approaches for various sample thickness and neutron energies. The half value layer of ABS-Bi10 sample is found to be as 4.9565 cm, which is much smaller than some commercial polymers: polyvinylidenechloride, polyamide, polyacrylonitrile, polyphenylenesulfide, and unsaturated polyester. With the usage of 3D printing technology, significant enhancements in neutron and gamma shielding were reported.

40 K, 226 Ra, 232 Th, 238 U, and 137 Cs massic activities were determined by gamma-spectrometry in limestones, marls, stream sediments, and soils of Kaštela Bay (Adriatic Sea, Croatia) coastal area. Their distribution, sources and potential influencing factors were studied. The lowest 40 K, 226 Ra, 232 Th, and 238 U massic activities were determined in limestones and the highest in soils, with the following median values, respectively: 7.2, 14, 0.8, and 5.3 Bq/kg in limestones and 518, 72, 71, and 31 Bq/kg in soils. All four radionuclides were of natural origin and reflected background values of the karstic area influenced by flysch/marl and terra rossa soil. Local TENORM disposal site did not influence the study area, but it will be needed to study its potential influence on marine sediments. Strong disequilibrium between 226 Ra and 238 U was found in limestones s.l. and soils, but not in marls and only moderately in stream sediments. This implies that limestones are more susceptible to selective 238 U leaching than marls, and soils more than stream sediments. 137 Cs was the only radionuclide of anthropogenic origin, with a global source only. It was detected in stream sediments and soils with median values of 5.4 and 31 Bq/kg, respectively. 137 Cs distribution was more heterogeneous in stream sediments than in soils, but soils generally presented higher activities. Soil is considered the most important reservoir of 137 Cs and its potential source.