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The paper discusses a photoactivation method for determining the activity of the long-lived isotope Ca relative to the activity of Co in irradiated reactor biological shielding concrete. It is proposed to use photonuclear reactions on cobalt and calcium isotopes: Co( , ) Co, Ca( , ) K, or Ca( , ) Ca Sc to determine the activity of Ca. The sensitivity of the proposed method is on the order of Bq/g, provided that semiconductor spectrometers with an ultrapure germanium detector are used. The structure and chemical compositions of the sample do not affect the proposed method. It avoids the long sample preparation times associated with radiochemical methods. [ABSTRACT FROM AUTHOR]

The decontamination properties of shampoos for cesium, strontium, and cobalt were determined. The method has been developed for determining the decontaminating properties of shampoos. The chemical part of the study includes the preparation of hair, which consists of forced pollution and subsequent washing. Stable isotopes were used in the work. This has increased the safety of staff during chemical hair research. The analytical part includes the quantitative determination of the cesium, strontium, and cobalt in the hair, which was carried out by the Particle-Induced X-ray Emission (PIXE) method using the analytical nuclear-physical complex “Sokol”. Various shampoos were analyzed, and their decontamination properties were determined. During the research, various samples of shampoos, which are presented on the market of Ukraine, were considered. It has been established that TM “Ringo” shampoo has the best deactivating properties for cesium (Kd - 574.0) and insignificant deactivating properties for strontium (Kd - 3.1) and cobalt (Kd - 3.6). It was determined that with multi-isotope contamination (a mixture of cesium, strontium, and cobalt isotopes) decrease in the deactivation coefficient for all isotopes was observed, which is due to the competition factor of the isotopes in the complexation process with shampoo. Reduction of decontaminating properties was observed on all samples of shampoos. [ABSTRACT FROM AUTHOR]

Another radionuclide of great interest is the PET radionuclide zirconium-89 ( SP 89 sp Zr) and the increased interest in immunoPET imaging probes for preclinical and clinical studies has led to a rising demand for this radionuclide. The work by Da Silva et al. [[18]] has been dedicated to developing new biomedical cyclotron irradiation and radiochemical isolation methods to produce SP 165 sp Er suitable for targeted radionuclide therapeutic studies and characterize a new agent targeting prostate-specific membrane antigen. The field of radiopharmaceuticals is constantly evolving thanks to the great contribution of specialists coming from different disciplines such as inorganic chemistry, radiochemistry, organic and biochemistry, pharmacology, nuclear medicine, physics, etc. 30304795 12 Borgna F., Ballan M., Favaretto C., Verona M., Tosato M., Caeran M., Corradetti S., Andrighetto A., Di Marco V., Marzaro G. Early Evaluation of Copper Radioisotope Production at ISOLPHARM. [Extracted from the article]

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The incorporation of marble particles into the framework of composite material through the polymerization of acrylic acid (AA) and acrylamide acid (AM) using induced gamma irradiation was performed. The novel poly[AA-AM]-marble composite was characterized by multiple analytical instruments such as: energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) analysis, differential thermal analysis-thermogravimetric analysis (DTA-TGA), Fourier transformer infrared (FTIR), surface area measurements using Brunauer–Emmett–Teller (BET) method and scanning electron microscope (SEM). Radioisotopes of fission (152+154Eu) and activation products (60Co) are the major environmental threats. Sorption of stable isotopes of cobalt and europium onto the synthesized composite material as the sorbent is applied. Sorption kinetics of Eu3+ and Co2+ were computed. The obtained results were analyzed by pseudo-first- and second-order, intraparticle diffusion, and Elovich kinetic models. It is deduced that the pseudo-second-order was more fitted and a chemisorption mechanism was suggested. The sorption capacity for Eu3+ and Co2+ on the prepared composite material was measured at the contact time (2 h) and pH = 4 (for Eu3+), pH = 6 (for Co2+) and it was found to be 91.2 and 13.1 mg/g, respectively. A promising result for the decontamination of both Eu and Co ions was obtained in various aquatic ecosystem applications such as: river water, tap water and groundwater. [ABSTRACT FROM AUTHOR]

Aflatoxins are natural mycotoxins that mainly occur in areas with humid climates. One of the methods for the successful elimination of aflatoxins is gamma radiation treatment. In this paper, gamma radiation's influence on the content of aflatoxins in hemp flour and microbiological properties (total number of microorganisms, molds, and potentially pathogenic bacteria) and nutritional values were investigated. The artificial radioactive isotope of cobalt Co‐60, with a dose rate of 10 kGy/hr, was used as the radiation source. Using high‐performance liquid chromatography, we determined that a dose of 4 kGy was sufficient to eliminate aflatoxins below the acceptable value. An irradiation dose of 8 kGy was sufficient to eliminate the total number of microorganisms and molds. Also, a treatment of 3 kGy is enough to remove all bacteria. Finally, it was shown that gamma irradiation does not affect the nutritional value of the product. Novelty Impact Statement: Hemp flour is rich in healthy fats, magnesium, fiber, and protein. However, it may be contaminated with aflatoxins, microorganisms, molds, and potentially pathogenic bacteria. Gamma irradiation is an effective method of food preservation that guarantees food decontamination and protection of nutrients. In this paper, an adequate dose of gamma radiation to preserve hemp flour has been established. [ABSTRACT FROM AUTHOR]

Simultaneous removal of radiocobalt and manganese by adsorption onto polyacrylonitrile/hexadecyltrimethylammonium bromide/potassium copper hexacyanoferrate (PAN/HDTMA/KCuHCF) composite was studied. The synthesized composite was characterized by Fourier-transformed infrared (FT-IR), thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The influence of the solution pH was studied in the range 1.5–7.8 and the results showed the effectiveness of the synthesized composite for simultaneous adsorption of radiocobalt and manganese in the pH range 2.5–6 at an adsorbent mass of 4 g/L. Adsorption kinetic data of manganese at the studied concentrations were best fitted by pseudo-second-order kinetic model and the diffusion study showed that the adsorption process was controlled by film diffusion. Thermodynamic parameters (ΔGo, ΔHo and ΔSo) were estimated and the results indicated that adsorption processes of the concerned (radio)toxicants were spontaneous and endothermic in nature. Of the studied isotherm models, Freundlich and Langmuir were the best ones for describing the adsorption isotherm data of radiocobalt and manganese, respectively. The adsorption capacity of PAN/HDTMA/KCuHCF was found to be 23.629 (for radiocobalt) and 62.854 (for manganese). Desorption of Radiocobalt and manganese loaded onto PAN/HDTMA/KCuHCF composite was studied using various desorbing agents at different concentrations. [ABSTRACT FROM AUTHOR]

Nowadays, cobalt isotopes 55Co, 57Co, and 58mCo are considered to be promising radionuclides in nuclear medicine, with 55Co receiving the most attention as an isotope for diagnostics by positron emission tomography. One of the current research directions is dedicated to its production using electron accelerators (via photonuclear method). In our work, the yields of nuclear reactions occurring during the irradiation of natNi and 60Ni by bremsstrahlung photons with energy up to 55 MeV were determined. A method of fast and simple cobalt isotopes separation from irradiated targets using extraction chromatography was developed.

Cesium and cobalt radioactive isotopes (134Cs and 60Co) are dangerous to human health due to their long half-life about 2.1 and 5.3 year, respectively. Developing a new composite used as an efficient sorbent for these is an urgent requirement for radioactive waste management. Herein, preparation of different materials such as aluminum silicate (AS), cultured of Chlorella vulgaris (NCV) alga, and aluminum silicate/Chlorella vulgaris (AS/NCV) composite 3:1 were prepared by wet chemical technique and used to remove the 134Cs and 60Co radionuclides. Different analytical techniques were used to characterize the prepared sorbents as SEM, TEM, XRD, BET, TGA/DTA, FTIR particle size analyzer, and pore size distribution. The factors affecting the sorption process as pH, temperature, contact time, and weight of adsorbent were studied. The sorption process was found to follow a pseudo-second-order mechanism. The monolayer capacity for 134Cs radionuclide onto the aluminum silicate, non-living Chlorella vulgaris biomass, and aluminum silicate/Chlorella vulgaris composites are 66.67, 83.54, and 90.11 mg/g, respectively, and for 60Co radionuclide are 59.31, 91.99, and 99.24 mg/g, respectively. The values of thermodynamic parameters indicate that the sorption process is endothermic and spontaneous. [ABSTRACT FROM AUTHOR]

The flux-weighted average cross-sections for the 59Co(γ , xn)58-55Co reactions have been measured with the bremsstrahlung end-point energies of 65 and 75 MeV by using the activation method in combination with the off-line γ -ray spectrometry. The measured cross-sections for the (γ , n) , (γ , 2 n) , (γ , 3 n) and (γ , 4 n) reactions of 59Co at 65 MeV are 15. 828 ± 0. 491 , 5. 003 ± 0. 206 , 0. 408 ± 0. 047 and 0. 039 ± 0. 008 mb, whereas at 75 MeV are 15. 653 ± 0. 361 , 4.965±0.289, 0. 389 ± 0. 062 and 0. 036 ± 0. 007 mb, respectively. The 59Co(γ , xn) reaction cross-sections as a function of photon energy were also theoretically simulated by using TALYS 1.9 code. Then the flux-weighted average cross-sections at different bremsstrahlung energies were obtained from the theoretical values and the literature data at lower energy based on mono-energetic photons. The present data are measured for the first time and are found to be in good agreement with the theoretical flux-weighted average values. It was found that the 59Co(γ , xn)58-55Co reaction cross-sections increase from their threshold values to a certain bremsstrahlung energy. After a certain energy, the individual 59Co(γ , xn) reaction cross-sections decrease with the increase of bremsstrahlung energy due to opening of other reaction channels. These two observations indicate the role of excitation energy and its partition in different reaction channels. All the four cobalt isotopes produced from the 59Co(γ , xn) reactions have medical and other applications. [ABSTRACT FROM AUTHOR]

Electronic transition spectrum of cobalt monoboride (CoB) in the visible region between 495 and 560 nm has been observed and analyzed using laser-induced fluorescence spectroscopy. CoB molecule was produced by the reaction of laser-ablated cobalt atom and diborane (B2H6) seeded in argon. Fifteen vibrational bands with resolved rotational structure have been recorded, which included transitions of both Co10B and Co11B isotopic species. Our analysis showed that the observed transition bands are ΔΩ = 0 transitions with Ω″ = 2 and Ω″ = 3 lower states. Four transition systems have been assigned, namely, the [18.1]3Π2-X3Δ2, the [18.3]3[uppercase_phi_synonym]3-X3Δ3, the [18.6]3- X3Δ3, and the [19.0]2-X3Δ2 systems. The bond length, ro, of the X 3Δ3 state of CoB is determined to be 1.705 Å. The observed rotational lines showed unresolved hyperfine structure arising from the nuclei, which conforms to the Hund's case (aβ) coupling scheme. This work represents the first experimental investigation of the CoB spectrum. [ABSTRACT FROM AUTHOR]

A synergistic approach involving theory and experiment has been used to study the structure and properties of neutral and negatively charged cobalt-coronene [Com(coronene)] complexes. The calculations are based on density functional theory with generalized gradient approximation for exchange and correlation potential, while the experiments are carried out using photoelectron spectroscopy of mass selected anions. The authors show that the geometries of neutral and anionic Co(coronene) and Co2(coronene) are different from those of the corresponding iron-coronene complexes and that both the Co atom and the dimer prefer to occupy η2-bridge binding sites. However, the magnetic coupling between the Co atoms remains ferromagnetic as it is between iron atoms supported on a coronene molecule. The accuracy of the theoretical results is established by comparing the calculated vertical detachment energies, and adiabatic electron affinities with their experimental data. [ABSTRACT FROM AUTHOR]