RESUMEN
Activation cross sections of alpha-particle-induced reactions on natural rhenium were measured. The stacked-foil activation technique and high-resolution gamma-ray spectrometry were used to derive the cross sections. The production cross sections of 190g, 189g, 188g, 187g, 186g, 185, 184Ir, 185Os, and 184g, 183gRe were determined up to 50 MeV. The cross sections of 185,184Ir were measured for the first time. The experimental results were compared with previous experimental data and theoretical calculations in the TENDL-2021 library.
RESUMEN
We synthesized Au/Fe3O4 microparticles. Initially, citrate-capped Fe3O4 micro-sized particles were synthesized by the co-precipitation method with an excess amount of trisodium citrate. Gold ions were reduced on the surface of citrate-capped Fe3O4 and grew as gold sub-microparticles with an average diameter of 210â nm on the surface. The characteristic SPR peak of gold nanoparticles on the surface of Fe3O4 was detected at 584â nm, whereas the absorption in the near-infrared region was increased. SEM images has proved that the synthesized Au/Fe3O4 composite microparticles has an average diameter of 1.7 micrometers. The results of XRD patterns proved the existence of both crystal phases of Fe3O4 and Au particles. To investigate the catalytic activity, the reaction rate constant of reduction of 2,4-dinitrophenol (2,4-DNP) and degradation of Congo red (CR), and methylene blue (MB) with NaBH4 in the presence of Au/Fe3O4 catalyst was monitored by UV-Vis spectroscopy. The initial reaction rate constant calculated from the change in characteristic peak absorptions of 2,4-dinitrophenol was 3.97×10-3â s-1, while the reaction rate constants for the degradation of CR and MB were 9.72×10-3â s-1 and 14.25×10-3â s-1 respectively. After 5 cycles, Au/Fe3O4 microparticles preserved 99 % of the reaction rate constant, exhibiting considerable recycling efficiency in the reduction of nitro groups.
RESUMEN
Sheep wool is one of the most common wastes derived from agriculture and also a great source of keratin. In this study, chemical reduction and alkali hydrolysis methods of extracting keratin from wool were studied for the purpose of reusing the waste wool, and the products were used to fabricate wet-spun hybrid fibers by mixing with PVA. The comparative yield of the two extraction methods was investigated, and the optimal precursor concentration ratio for keratin extraction was identified. The effects of keratin concentration and wet-spinning flow rate on the mechanical properties of fabricated fibers were studied. Therefore, this study encourages the further investigation of wool keratin-based hybrid biomaterials, which could provide a new way to reuse waste wool.
RESUMEN
Activation cross sections of proton-induced reactions on natural platinum were measured. The stacked-foil activation technique and high-resolution gamma-ray spectrometry were used. The production cross sections of 198, 196, 196m2, 195, 194, 193, 192, 191Au, 191Pt, and 192, 190Ir were determined up to 30 MeV. The experimental results were compared with previous experimental data and theoretical calculations in the TENDL-2019 library.
Asunto(s)
Platino (Metal) , ProtonesRESUMEN
Activation cross sections of alpha-particle-induced reactions on natural vanadium were measured. The production cross sections of 54, 52gMn, 51Cr, 48V, and 47, 46gSc were determined up to 50 MeV. The stacked-foil activation technique and high-resolution gamma-ray spectrometry were used. The experimental results were compared with previous experimental data and theoretical calculations in the TENDL-2019 library. The physical yield of the medical radionuclide 52gMn was derived from the measured cross sections.
Asunto(s)
Partículas alfa , Vanadio , Partículas alfa/efectos adversos , Radioisótopos/química , Espectrometría gammaRESUMEN
Activation cross sections of the medically interesting radionuclide 45Ti were investigated in the deuteron-induced reaction on 45Sc. 45Ti can be produced in a radioactive-contamination-free form in the 45Sc(d,2n)45Ti reaction below 15 MeV deuteron energy. The stacked foil activation technique and γ-ray spectrometry were used to determine the cross sections. The physical yield of 45Ti was deduced from the measured cross sections.