Volume 109, Issue 10

Excitation functions of the reactions 27 Al(d,αp) 24 Na, 27 Al(d,2p) 27 Mg and 27 Al(d,p) 28 Al were measured by the activation technique up to deuteron energies of 37 MeV. The available experimental databases of the reaction products 27 Mg and 28 Al were extended and compared with the nuclear model calculations based on the code TALYS-1.8. Our measured data are reproduced well by the model calculations after adjustment of a few free input parameters. The cross-section ratio of the (d,αp) to (d,2p) process as a function of projectile energy was deduced from the measured data, and the result is interpreted in terms of competition between a proton and an α-particle emission.

32 Si ( T 1/2  = 153(19) y) is an extremely rare, naturally-occurring isotope that has been considered as a geochronometer suitable for radiometric dating over the time span from 100 to 1000 years ago – a time span that has proved rather difficult to explore in this manner. Past attempts to determine the 32 Si half-life have resulted in a wide range of values possessing significant uncertainties because only low-activity samples could be made available for such measurements. Utilizing the 590 MeV ring cyclotron at PSI, megabecquerel quantities of 32 Si have been produced by exposing metallic vanadium discs to high-energy protons in order to induce spallation. A radiochemical separation procedure has been successfully developed and applied to the irradiated discs as part of the SINCHRON project, based on a combination of ion-exchange and extraction resins. The process was shown to be reliable and robust with a high chemical yield. Radiochemically pure 32 Si solutions with activity concentrations of up to several kBq/g can be produced to perform individual measurements (AMS, ICP-MS, LSC) for various studies. Thus, a careful redetermination of the 32 Si half-life has become feasible to begin the first steps toward the confident implementation of this radionuclide for geochronological purposes.

A chelating matrix prepared by immobilizing N-hydroxyl amine onto graphene oxide functionalized with aspartic acid (GO-HDX) was applied to recover UO 2 2+ from their SO 4 2− leach liquor. SEM-EDAX, FT-IR, TGA, and XRD instruments, in addition, Raman spectroscopy (IR-Raman), were used to analyze the synthesized GO-HDX. The static extraction technique optimized various physicochemical parameters that impacted the UO 2 2+ extraction. The optimal pH, time of contact, initial concentration, GO-HDX dose, temp., foreign ions, and eluting agents were gained. The experimental equilibrium documents were assessed using Langmuir and Freundlich equations. The Langmuir equation model quite fits the investigational adsorption data with a maximum uptake of 277.78 mg/g, and it implied the attending of monolayer coverage of adsorbed molecules. Pseudo-first- and pseudo-second-order analyses were done to inspect the kinetic results. The data indicated that pseudo-second-order kinetics fit all concentrations. The intended thermodynamic factors were ∆G° negative values and ∆H° positive value. The data signified that the UO 2 2+ extraction onto GO-HDX was spontaneous adsorption and endothermic at higher temperatures. The regeneration efficiency of GO-HDX was 98% using 1 M HCl.

In this work, diethylenetriamine pentamethylenephosphonic acid (DTPMP) was ultilized into preparing of Zr(IV) organophosphates hybrids (Zr-DTPMP- x , x  was the molar ratio of Zr(IV)/DTPMP in the synthetic process, x  = 0.5, 1, 2, and 3) using a hydrothermal method. The physical and chemical properties of Zr-DTPMP- x were characterized by SEM&EDS, FT-IR, XRD, Zeta potential, XPS, TGA and contact angle analysis. Moreover, the adsorptive performances of Zr-DTPMP- x for U(VI) were investigated. The adsorption results showed that the optimum molar ratio of Zr(IV) to phosphine, pH, equilibrium time, and dosage was 0.5, 4.0, 180 min, and 10 mg, respectively. Besides, the adsorption of U(VI) was in accordance with the pseudo-second-order kinetic model and Sips isothermal model. Moreover, the adsorption capacity determined by Sips isothermal model was 181.34 mg g −1 for Zr-DTPMP-0.5. Furthermore, the adsorptive selectivity of Zr-DTPMP-0.5 for U(VI) was superior than the others. Zr-DTPMP-0.5 may be a powerful candidate for diminishing the contamination of U(VI).

The objective of this study is to label Amoxicillin with radioactive iodine ( 125 I-AC) via direct electrophilic substitution to act as a promising tracer for inflammation imaging. The highest labeling yield of 80% was achieved after studying all the parameters affecting the labeling reaction using Iodogen (IG) as an oxidizing agent. Molecular Modeling Structure was done using MOE program to predict the suitable 125 I position. The product structure was established by a cold iodination reaction using Iodine-127. Biological evaluation of ( 125 I-AC) was carried out using groups of inflamed mice with different exogenous agents such as E.Coli and Turpentine oil. The ( 125 I-AC) shows an in vitro stability of about 97% after 24 h.While doing in vivo studies over 4 h, the tracer stability of 99% was observed.

In this article, graphite fine powder and two types of activated carbon (AC) namely based-on waste corn and sugarcane bagasse were implemented as reinforcers for the nitrile rubber (NBR). Both types of AC were prepared through a low-temperature chemical carbonization treatment. Each type of these fillers, at 5, 10, and 15 wt%, was mixed with NBR on a rubber mill and pressed under heat to develop sheets to be gamma irradiated at 100 kGy. Filler characterization using Fourier Transform Infrared spectrophotometer (FTIR) spectroscopy and scanning electron microscopy (SEM) were discussed. X-ray diffraction (XRD) proved that graphite has a crystalline structure but corn and bagasse ACs have amorphous nature. Furthermore, dynamic light scattering (DLS) analysis was used to determine the particle size of the studied fillers. In addition, mechanical properties, XRD, thermal stability, and SEM of the prepared unirradiated or irradiated NBR‒composites were investigated. The physicomechanical features of the NBR matrix could be enhanced by the presence of reinforcing fillers, even at relatively low filler loading. The composites filled with graphite showed superior mechanical parameters and also have the highest thermal stability as indicated by their high-temperature mass loss (Tm). Generally, irradiated samples expressed grander properties than unirradiated ones as a result of the radiation-induced crosslinking structures.

Radon ( 222 Rn) exposure in the environment is an important issue, and many pathways exist for radon exposure to humans. One of these pathways is 222 Rn release through the consumption of natural gas. The issues of 222 Rn concentration measurement techniques and worldwide concentration distribution were reviewed in natural gas, with emphasis on performing an active method to determine 222 Rn concentration in LPG and CNG gases used in Cyprus. The obtained results were compared with 222 Rn concentration in natural gas worldwide and UNSCEAR reports. The average 222 Rn concentration value in LPG gas was observed higher than CNG gas. Also, the 222 Rn concentration in LPG and CNG gases was less than the UNSCEAR reported value.