Band 111, Heft 8

The 237 Np ( t 1/2 = 2.1 × 10 6  y) nuclide is produced in nuclear facilities. Its investigation is relevant to earth sciences as concerns environmental pollution and material circulation. We expected that this nuclide should be able to be analyzed by mass spectrometry with a neptunium tracer as a spike, such as that of 236g Np ( t 1/2 = 1.5 × 10 5  y). Our research group has collected fundamental data for cross-sections of the 232 Th + 7 Li reaction for use in spike production. In addition to the complete fusion reaction, incomplete fusion also occurs, especially in the reaction of 7 Li, which splits into α and t , and only a part of the projectile fuses with the target nucleus. In this study, the excitation functions of Pa isotopes, as products of the incomplete fusion reaction, were measured. The reaction mechanism is discussed by comparing the experimental values with those calculated using the EMPIRE code. In addition, we investigated the effect of incomplete fusion reaction on the entire reaction.

This paper presents first investigations on a novel An(III), Ln(III), Cs(I) and Sr(II) co-extraction conceptual process using a CHON solvent composed of the calixarene crown-ether MAXCalix and the diglycolamide TODGA in a 1-octanol/kerosene diluent. The co-extraction is followed by a sequential stripping of (1) Cs(I) and Sr(II), (2) An(III) and (3) Ln(III).

A novel bis(methylimidazolium) ionic liquid 3,3′-(pentane-1,5-diyl) bis(1-methylimidazolium) bis(trifluoromethanesulfonul)imide [C 5 (mim) 2 ][Tf 2 N] 2 has been synthesized. Its effect on the extraction of U(VI), Th(IV), Am(III), and lanthanides(III) from nitric acid solutions with a polydentate neutral bis(carbamoylmethylphosphine oxide) ligand L containing two bidentate fragments Ph 2 P(O)CH 2 C(O)NH–, interconnected by 4,7,10-trioxatridecane spacer through amide nitrogen atoms has been investigated. The efficiency of the extraction of metal ions with solutions of L in 1,2-dichloroethane (DCE) significantly increases in the presence of [C 5 (mim) 2 ][Tf 2 N] 2 . A synergistic effect in the extraction of metal ions in this system has been explained with the high hydrophobicity of the Tf 2 N − anions, which are involved in the formation of extracted complexes as counterions. The value of the synergistic effect decreases with increasing acidity of the aqueous phase. The influence of the composition of the aqueous and organic phases on the efficiency of the extraction of metal ions into the organic phase is considered, and the stoichiometry of the extracted complexes is determined. The effect of the HTf 2 N coextraction with L on the extraction of metal ions in the L  – [C 5 (mim) 2 ][Tf 2 N] 2 system is discussed. The synergistic effect in the extraction of Ln(III) from 3 M HNO 3 solutions with the mixture of L and [C 5 (mim) 2 ][Tf 2 N] 2 in DCE is higher than that in the L  – [C 4 mim][Tf 2 N] – DCE system.

Exchange of oxygen stable isotopes (δ 18 O values) between precipitation waters and uranium oxides is governed by thermodynamics or kinetics. It has been assumed that meteoric waters can be related to precipitation waters in uranium ore concentrates and their calcined and reduced uranium oxide products. With this assumption, the δ 18 O values of uranium materials could provide forensic signatures that identify the production history and geolocation of nuclear materials. To further exploit the potential of δ 18 O values in nuclear material analysis, this study examines the oxygen stable isotope exchange in two UOCs, magnesium diuranate (MDU) and sodium diuranate (SDU). MDU and SDU were synthesized from solutions of uranyl nitrate hexahydrate using precipitation waters with unique oxygen isotope compositions. The structures of the MDU and SDU were analyzed using powder X-ray diffraction (p-XRD) and thermal mass loss curves, while the δ 18 O values of waters generated during thermal decomposition were analyzed using a thermogravimetric analyzer coupled to an isotope ratio infrared spectrometer (TGA-IRIS). By p-XRD, the MDU was uniform and amorphous across all syntheses with residual crystalline material incorporated as a minor component. Combined with the TGA results, all of the MDU is likely amorphous MgU 2 O 7 ·3H 2 O with MgO impurities present throughout. In contrast, the SDU synthesis resulted in multiple phases with many samples exhibiting crystalline phases including a combination of Na(UO 2 ) 4 O 2 (OH) 5 ·5H 2 O and Na 2 (UO 2 ) 6 O 4 (OH) 6 ·8H 2 O with a Na 2 U 2 O 7 minor phase. A small fraction of the SDU samples were amorphous with no crystalline XRD peaks observed. Mass loss curves of the SDU samples revealed that the amorphous samples contained inclusions of similar crystalline phases compared to the crystalline materials. The uniformity of the MDU samples enabled highly reproducible measurements of δ 18 O values of the water vapor yielded from two dehydration events at 170 °C and 500 °C. In contrast, the multiphase composition of the SDU samples resulted in poor reproducibility in δ 18 O values. Neither system revealed any correlation between the δ 18 O values of precipitation water and the waters released during dehydration of the UOCs.

79 Se is one of the important radionuclides in the safety evaluation of high-level radioactive waste repository due to its long half-life and highly fissionable radioactivity. Nanoscale pyrite-zero nickel composites (FeS 2 /Ni 0 ) were fabricated by ball milling method for selenium(IV) (Se(IV)) adsorption from aqueous solution. The effects of pH, solid-liquid ratio, time, temperature, initial concentration of Se(IV) on the adsorption of Se(IV) by FeS 2 /Ni 0 were investigated. FeS 2 /Ni 0 was characterized by SEM, XPS, XRD, FT-IR, BET and Zeta potential, and the mechanism of removing Se(IV) was analyzed. The results showed that FeS 2 /Ni 0 had a good removal effect on Se(IV). When pH was 5.5, the solid-liquid ratio was 0.1 g L −1 , the reaction time was 40 min, the maximum adsorption capacity of Se(IV) by FeS 2 /Ni 0 could reach 259 mg g −1 . The research results can provide a theoretical basis for the treatment of wastewater containing Se(IV).

Salt cedar ( Tamarix gallica L.) is an important xero–halophytic tree used for its medicinal properties to treat cancer, gastrointestinal syndromes, diabetes and infections. In the present investigation, instrumental neutron activation analysis (INAA) was carried out to evaluate some major and trace elements (As, Ba, Br, Ca, Ce, Co, Cr, Cs, Eu, Fe, K, La, Na, Rb, Sb, Sc, Sm, Tb, Th, and Zn) in this species. The quality of the results was assessed by the analysis of CRM-GSV4 tea leaves; a good agreement was achieved between the measured and recommended data. The results show that T. gallica contained high levels of Ca, K, Na and Fe, while elements toxic to humans (As, Br, and Sb) were below the tolerable limits reported in the World Health Organization database (WHO/FAO). Macro–and microelements essential to humans were present in T. gallica leaves with significant levels in the following order: Ca > Na > K > Fe > Zn > Cr > Co. T. gallica could provide a new promising therapeutic source for pharmacological purposes.

In this work, polymeric composite films were fabricated utilizing stable, non-toxic, soluble, low-cost, good mechanical, and biocompatible polymers such as CMC and PVA with the waste of one of the most current fruits consumed worldwide banana peel waste (BP) as a filler. Sequences of carboxymethyl cellulose/polyvinyl alcohol/banana peel (CMC/PVA/BP) composite films with various amounts of BP utilizing eco-friendly technique (electron beam) (EB) irradiation were prepared to eliminate common hazardous organic pollutants such as methylene blue (MB) dye from its solutions. Physical characteristics like; swelling and gel % were examined. The chemical structure, thermal stability, and surface morphology were examined utilizing FT-IR, TGA, DSC, XRD, EDX, and SEM. Additionally, the UV/Vis spectroscopy study was investigated to study the impact of the various parameters such as irradiation, contact time, pH, temperature, adsorbent dosage, and initial concentration on removal efficiency % of MB dye onto the prepared composite films. The adsorption process fitted with the Langmuir model, pseudo-second-order kinetic model, endothermic, favorable, and spontaneous. The adsorption capacity of MB dye onto the CMC/PVA/BP composite film was 19.6 mg/g at the optimum conditions: irradiation dose = 20 kGy, contact time = 120 min, pH = 10, temperature = 25 °C, adsorbent dosage = 0.1 g and initial conc. = 10 mg/L.