Subjects -> CHEMISTRY (Total: 928 journals)
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CHEMISTRY (661 journals)            First | 1 2 3 4 | Last

Showing 401 - 600 of 735 Journals sorted alphabetically
Journal of Molecular Liquids     Hybrid Journal   (Followers: 3)
Journal of Molecular Modeling     Hybrid Journal   (Followers: 5)
Journal of Molecular Recognition     Hybrid Journal   (Followers: 2)
Journal of Molecular Spectroscopy     Hybrid Journal   (Followers: 6)
Journal of Molecular Structure     Hybrid Journal   (Followers: 6)
Journal of Nanoparticles     Open Access   (Followers: 4)
Journal of Nanostructure in Chemistry     Open Access   (Followers: 8)
Journal of Organometallic Chemistry     Hybrid Journal   (Followers: 24)
Journal of Photochemistry and Photobiology     Open Access  
Journal of Photochemistry and Photobiology A: Chemistry     Hybrid Journal   (Followers: 3)
Journal of Photochemistry and Photobiology B: Biology     Hybrid Journal   (Followers: 4)
Journal of Photochemistry and Photobiology C: Photochemistry Reviews     Full-text available via subscription   (Followers: 3)
Journal of Polymer & Composites     Full-text available via subscription   (Followers: 17)
Journal of Polymer and Biopolymer Physics Chemistry     Open Access   (Followers: 7)
Journal of Polymer Science Part A: Polymer Chemistry     Hybrid Journal   (Followers: 92)
Journal of Polymers     Open Access   (Followers: 7)
Journal of Porphyrins and Phthalocyanines     Hybrid Journal   (Followers: 1)
Journal of Progressive Research in Chemistry     Open Access  
Journal of Pure and Applied Chemistry Research     Open Access   (Followers: 3)
Journal of Raman Spectroscopy     Hybrid Journal   (Followers: 14)
Journal of Research and Education Chemistry     Open Access   (Followers: 1)
Journal of Research Updates in Polymer Science     Hybrid Journal   (Followers: 2)
Journal of Rubber Research     Hybrid Journal   (Followers: 1)
Journal of Saudi Chemical Society     Open Access  
Journal of Solid State Chemistry     Hybrid Journal   (Followers: 13)
Journal of Solution Chemistry     Hybrid Journal   (Followers: 1)
Journal of Structural Chemistry     Hybrid Journal   (Followers: 1)
Journal of Sulfur Chemistry     Hybrid Journal   (Followers: 1)
Journal of Supercritical Fluids     Hybrid Journal   (Followers: 3)
Journal of Superhard Materials     Hybrid Journal  
Journal of Surface Science and Technology     Hybrid Journal  
Journal of Surfactants and Detergents     Hybrid Journal   (Followers: 3)
Journal of Taibah University for Science     Open Access  
Journal of the American Chemical Society     Hybrid Journal   (Followers: 326)
Journal of the American Society for Mass Spectrometry     Hybrid Journal   (Followers: 31)
Journal of the American Society of Brewing Chemists     Full-text available via subscription   (Followers: 2)
Journal of the Chilean Chemical Society     Open Access   (Followers: 2)
Journal of the Chinese Chemical Society     Hybrid Journal  
Journal of the Indian Chemical Society     Hybrid Journal  
Journal of The Indonesian Society of Integrated Chemistry     Open Access  
Journal of the Iranian Chemical Society     Hybrid Journal   (Followers: 1)
Journal of the Korean Society for Applied Biological Chemistry     Hybrid Journal  
Journal of the Mexican Chemical Society     Open Access   (Followers: 1)
Journal of the Serbian Chemical Society     Open Access  
Journal of the Turkish Chemical Society, Section A : Chemistry     Open Access  
Journal of Theoretical and Computational Chemistry     Hybrid Journal   (Followers: 9)
Jurnal Inovasi Pendidikan Kimia     Open Access  
Jurnal Kimia (Journal of Chemistry)     Open Access  
Jurnal Kimia Riset     Open Access  
Jurnal Pendidikan Kimia     Open Access  
Jurnal Penelitian Sains (JPS)     Open Access  
Karbala International Journal of Modern Science     Open Access  
Kinetics and Catalysis     Hybrid Journal   (Followers: 4)
Konfigurasi : Jurnal Pendidikan Kimia dan Terapan     Open Access  
Korea-Australia Rheology Journal     Hybrid Journal   (Followers: 1)
Langmuir     Hybrid Journal   (Followers: 58)
Lebensmittelchemie     Hybrid Journal   (Followers: 1)
Lipid Insights     Open Access  
Luminescence     Hybrid Journal   (Followers: 2)
Macromolecular Materials & Engineering     Hybrid Journal   (Followers: 5)
Macromolecular Rapid Communications     Hybrid Journal   (Followers: 10)
Macromolecular Research     Hybrid Journal   (Followers: 2)
Macromolecular Symposia     Hybrid Journal   (Followers: 3)
Macromolecular Theory and Simulations     Hybrid Journal   (Followers: 2)
Macromolecules     Hybrid Journal   (Followers: 48)
Magnetic Resonance in Chemistry     Hybrid Journal   (Followers: 8)
Magnetochemistry     Open Access  
Marine Chemistry     Hybrid Journal   (Followers: 6)
Marine Drugs     Open Access   (Followers: 1)
MATEC Web of Conferences     Open Access  
Materials Advances     Open Access   (Followers: 2)
Materials and Devices     Open Access  
Materials Characterization     Hybrid Journal   (Followers: 32)
Materials Chemistry Frontiers     Hybrid Journal   (Followers: 4)
Materials Horizons     Hybrid Journal   (Followers: 6)
Materials Research Bulletin     Hybrid Journal   (Followers: 25)
Materials Science-Poland     Open Access   (Followers: 1)
Materials Sciences and Applications     Open Access   (Followers: 2)
Medicinal Chemistry Research     Hybrid Journal   (Followers: 8)
Mediterranean Journal of Chemistry     Open Access  
Metallography, Microstructure, and Analysis     Hybrid Journal   (Followers: 1)
Micro and Nano Systems Letters     Open Access   (Followers: 6)
Microchimica Acta     Hybrid Journal   (Followers: 2)
Microporous and Mesoporous Materials     Hybrid Journal   (Followers: 9)
Modern Chemistry & Applications     Open Access   (Followers: 1)
Modern Research in Catalysis     Open Access  
Molbank     Open Access  
Molecular Catalysis     Hybrid Journal   (Followers: 5)
Molecules     Open Access   (Followers: 4)
Molecules and Cells     Hybrid Journal   (Followers: 1)
Monatshefte für Chemie - Chemical Monthly     Hybrid Journal   (Followers: 4)
Mongolian Journal of Chemistry     Open Access  
Moscow University Chemistry Bulletin     Hybrid Journal   (Followers: 1)
MRS Bulletin     Full-text available via subscription   (Followers: 4)
Nachrichten aus der Chemie     Hybrid Journal   (Followers: 13)
Nano Convergence     Open Access   (Followers: 1)
Nano Materials Science     Open Access   (Followers: 1)
Nano Reviews & Experiments     Open Access   (Followers: 14)
Nano Select     Open Access  
Nanochemistry Research     Open Access   (Followers: 1)
Nanoscale     Hybrid Journal   (Followers: 18)
Nanoscale Advances     Open Access  
Nanoscale Horizons     Hybrid Journal  
Nanoscale Research Letters     Open Access   (Followers: 8)
Nanoscience and Nanotechnology Letters     Full-text available via subscription   (Followers: 24)
Natural Product Communications     Open Access  
Natural Product Reports     Hybrid Journal   (Followers: 10)
Natural Science     Open Access   (Followers: 8)
Natural Volatiles & Essential Oils     Open Access  
Nature Chemistry     Full-text available via subscription   (Followers: 96)
Nature Protocols     Full-text available via subscription   (Followers: 73)
Nature Reviews Chemistry     Hybrid Journal   (Followers: 17)
New Journal of Chemistry     Hybrid Journal   (Followers: 16)
Nitric Oxide     Hybrid Journal  
Nitrogen     Open Access  
Nukleonika     Open Access  
Open Chemistry Journal     Open Access  
Open Conference Proceedings Journal     Open Access  
Open Journal of Chemistry     Open Access  
Open Journal of Composite Materials     Open Access   (Followers: 22)
Open Journal of Inorganic Non-metallic Materials     Open Access   (Followers: 2)
Open Journal of Medicinal Chemistry     Open Access   (Followers: 4)
Open Journal of Polymer Chemistry     Open Access   (Followers: 12)
Open Journal of Synthesis Theory and Applications     Open Access  
Open Medicinal Chemistry Journal     Open Access  
Orbital - The Electronic Journal of Chemistry     Open Access   (Followers: 1)
Organic & Biomolecular Chemistry     Hybrid Journal   (Followers: 55)
Organometallics     Hybrid Journal   (Followers: 18)
Oxidation of Metals     Hybrid Journal   (Followers: 16)
Passer Journal of Basic and Applied Sciences     Open Access  
Peptide Science     Full-text available via subscription  
Pharmaceuticals     Open Access   (Followers: 4)
Pharmaceutics     Open Access   (Followers: 5)
Phosphorus, Sulfur, and Silicon and the Related Elements     Hybrid Journal   (Followers: 2)
Photochemistry and Photobiology     Hybrid Journal   (Followers: 3)
Physical Science International Journal     Open Access  
Physics and Materials Chemistry     Open Access   (Followers: 1)
Phytochemistry     Hybrid Journal   (Followers: 4)
Phytochemistry Letters     Full-text available via subscription   (Followers: 1)
Plasma     Open Access   (Followers: 3)
Plasma Chemistry and Plasma Processing     Hybrid Journal   (Followers: 3)
Polycyclic Aromatic Compounds     Hybrid Journal  
Polyhedron     Hybrid Journal   (Followers: 4)
Polymer Chemistry     Hybrid Journal   (Followers: 24)
Polymer crystallization     Hybrid Journal  
Polymer Degradation and Stability     Hybrid Journal   (Followers: 23)
Polymer Engineering & Science     Hybrid Journal   (Followers: 14)
Polymer Reviews     Hybrid Journal   (Followers: 32)
Polymer Science Series D     Hybrid Journal   (Followers: 3)
Polymer Testing     Hybrid Journal   (Followers: 198)
Polymer-Plastics Technology and Materials     Hybrid Journal   (Followers: 5)
Polymers     Open Access   (Followers: 21)
Polymers from Renewable Resources     Hybrid Journal  
Proceedings of the Combustion Institute     Full-text available via subscription   (Followers: 8)
Processes     Open Access  
Progress in Lipid Research     Hybrid Journal   (Followers: 3)
Progress in Organic Coatings     Hybrid Journal   (Followers: 7)
Progress in Polymer Science     Full-text available via subscription   (Followers: 36)
Progress in Reaction Kinetics and Mechanism     Open Access  
Progress in Solid State Chemistry     Full-text available via subscription   (Followers: 3)
Progress in Surface Science     Full-text available via subscription   (Followers: 3)
Protein Science     Hybrid Journal   (Followers: 43)
Radiochemistry     Hybrid Journal   (Followers: 1)
Rapid Communications in Mass Spectrometry     Hybrid Journal   (Followers: 32)
Reaction Chemistry & Engineering     Hybrid Journal  
Reaction Kinetics, Mechanisms and Catalysis     Hybrid Journal   (Followers: 3)
Reactions     Open Access  
Reportes Científicos de la FaCEN     Open Access  
Research Journal of Phytochemistry     Open Access   (Followers: 1)
Resources Chemicals and Materials     Full-text available via subscription   (Followers: 5)
Results in Chemistry     Open Access  
Results in Geochemistry     Open Access  
Results in Surfaces and Interfaces     Open Access  
Review Journal of Chemistry     Hybrid Journal   (Followers: 1)
Reviews in Mineralogy and Geochemistry     Hybrid Journal   (Followers: 4)
Revista Boliviana de Química     Open Access  
Revista CENIC. Ciencias Quimicas     Open Access  
Revista Colombiana de Ciencias Químico-Farmacéuticas     Open Access  
Revista Colombiana de Química     Open Access  
Revista Cubana de Química     Open Access  
Revista de Ciencia y Tecnología     Open Access  
Revista de Ciencias     Open Access  
Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales     Open Access  
Revista de la Sociedad Química del Perú     Open Access  
Revista de la Societat Catalana de Química     Open Access  
Revista de Química     Open Access   (Followers: 6)
Revista Debates em Ensino de Química     Open Access  
Revista ION     Open Access  
RSC Advances     Open Access   (Followers: 27)
RSC Chemical Biology     Open Access  
RSC Medicinal Chemistry     Hybrid Journal   (Followers: 6)
Russian Journal of Bioorganic Chemistry     Hybrid Journal   (Followers: 1)
Russian Journal of Coordination Chemistry     Hybrid Journal   (Followers: 1)
Russian Journal of General Chemistry     Hybrid Journal   (Followers: 1)
Russian Journal of Inorganic Chemistry     Hybrid Journal  
Sainstek : Jurnal Sains dan Teknologi     Open Access  
Science China Chemistry     Hybrid Journal   (Followers: 2)
Science Talks     Full-text available via subscription   (Followers: 4)
Sciences & Technologie A : sciences exactes     Open Access  
Scientific Journal of Frontier Chemical Development     Open Access   (Followers: 2)

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Radiochemistry
Journal Prestige (SJR): 0.349
Citation Impact (citeScore): 1
Number of Followers: 1  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1608-3288 - ISSN (Online) 1066-3622
Published by Springer-Verlag Homepage  [2469 journals]
  • Wall Rock Alteration, Uranium Mineralization, and Potentiality of Uranium
           and Iron Dissolution from Mineralized Abu Rusheid Gneiss Rock, South
           Eastern Desert, Egypt

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      Abstract: Ferrugination, sericitization, desulfitization, chloritization, and kaolinitization of hydrothermal origin are the main wall rock alterations occurring within the NNW shear zones at Abu Rusheid area. The secondary uranium minerals occur as hair-like radiated spots and thin micaceous flakes with canary and yellow color, which are deposited along the small cracks and microfractures of altered gneiss and lamprophyre dyke and coat surfaces of hematitized rock. The radiometric measurements proved that the uranium content increases from sericitized gneiss (average 317.9 ppm) to ferruginated gneiss (average 863.1 ppm) and then to altered lamprophyre dyke (average 1352.7 ppm). The latter is the most radioactive zone along the NNW shear zones and is considered as a good trap for the uranium leached from the host rock due to the high ability of iron oxides and clays to adsorb radioactive elements from their solutions. Therefore, the present work focuses on the uranium leaching from Abu Rusheid area using sulfuric acid. The effect of sulfuric acid concentration, liquid/solid ratio, contact time, and leaching temperature on the leaching efficiency has been investigated. The data obtained show that about 74.0% of uranium can be leached successfully under the following conditions: sulfuric acid concentration 4 M, liquid/solid ratio 10 mL/g, room temperature, 6.0 h. The leaching kinetics is well interpreted with shrinking core model with control by diffusion through a porous product layer. The diffusion-controlled process is characterized by the activation energy of 6.3 kJ mol–1.
      PubDate: 2022-04-01
       
  • Sorption of Cs(I) in the Clays of the Markovskoye (Belarus) and 10th
           Khutor (Khakasia, Russia) Deposits

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      Abstract: The mineral composition and sorption parameters of natural clay samples from the Markovskoye (Belarus) and 10th Khutor (Khakassia, Russia) deposits were studied. The content of the main clay minerals in clay samples from these deposits is, wt %: Markovskoye—montmorillonite 37.6, illite 3.6, kaolinite 14.7; 10th Khutor—montmorillonite 58.8. The time for reaching sorption equilibrium for the studied clay samples at 3.5 × 10–9 and 10–3 M Cs+ concentrations in the solution is about 24 h. It has been determined that clays have two types of sorption sites, T1 and T2, which differ in their selectivity and capacity relative to Cs+. The Cs+ sorption capacities of T1 and T2 sites of clay deposits are, respectively: Markovskoe, 3.2 × 10–5 and 0.03 mol/kg; 10th Khutor, 2.5 × 10–6 and 0.07 mol/kg. It was found that the sorption of 137Cs from solutions with a specific activity of no more than 1.3 × 1010 Bq/dm3 is higher on clay from the Markovskoye deposit compared to that on clay from the 10th Khutor deposit. The conclusion is made about the possibility of the Markovskoye deposit use as part of the underlying screen of the disposal facility for low- and intermediate-level radioactive waste of the Belarusian NPP.
      PubDate: 2022-04-01
       
  • Technetium-99m Labeling of Antineoplaston A10 and Its Bioevaluation as a
           Potential Tumor Imaging Agent

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      Abstract: Antineoplastons (ANPs) are compounds that have antitumor activities. ANPA10 was labeled with technetium-99m using stannous chloride as a reducing agent with the labeling yield of approximately 98% at pH 6. The conditions required to optimize the labeling yield were studied in details. The tumor binding specificity of the [99mTc]Tc-ANPA10 radiotracer was evaluated. The uptake of [99mTc]Tc-ANPA10 in ascitic fluid uptake was 10, 16, and 12.8% ID/g at 30, 60, and 120 min post injection. The preclinical biological evaluation of [99mTc]Tc-ANPA10 complex in solid tumor bearing mice showed a high tumor uptake at 1 h post injection (11.2 ± 0.30 % ID/g). The selective uptake of [99mTc]Tc-ANPA10 in solid tumors and rapid clearance from nontarget organs make it promising for solid tumor imaging, but further clinical trials are required.
      PubDate: 2022-04-01
       
  • Development of a Sorption Technique for the Selective Separation of
           Plutonium and Americium from Nitric Acid Intermediate-Level Wastes of
           Chemical and Metallurgical Production

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      Abstract: The sorption extraction of Pu and Am from nitric acid simulation solutions were studied on a solid extractant (TVEX) AXIONIT MND 40T in a static mode. It is shown that the distribution coefficients of Pu and Am on TVEX reach maximum values ​​in 7.5 M HNO3. Desorbing solutions were selected that make it possible to selectively extract the target components from the TVEX phase. For effective desorption of Pu, it is advisable to use a reducing desorbing solution of the following composition: 3.5 M HNO3, 10 g/L ascorbic acid (C6H8O6), 0.2 M N2H4; for desorption of Am, a solution of 10 g/L diethylenetriaminepentaacetic acid (DTPA) with pH 5–6. The values ​​of the full dynamic exchange capacity (FDEC) of TVEX for Pu and Am were 12 and 16 g/L, respectively. The fundamental possibility of sorption separation of Pu and Am from real intermediate-level liquid wastes (ILW) of chemical and metallurgical production (CMP) at TVEKS was established. A two-stage sorption technique for the separation of Pu and Am from liquid ILW of CMP was developed, which provides for the adjustment of the HNO3 concentration in solutions, the extraction of Pu on the Purolite S957 cation exchange resin, the concentration of Am from the filtrate on the TVEX, the desorption of Pu and Am from the sorbent phase, the regeneration of the TVEX, and the additional purification of the Am desorbate on the cation exchange resin Purolite S957 if it is necessary to yield a purified 241Am concentrate.
      PubDate: 2022-04-01
       
  • Physicochemical Forms of Iodine in the Primary Coolant of a Nuclear Power
           Plant with Ammonia Water Chemistry

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      Abstract: The article is devoted to the determination of physiochemical forms of iodine radionuclides in the primary loop coolant of transportable nuclear power plants (TNPP) of pressurized water type with ammonia water chemistry. The main form of iodine radionuclides 131I–135I in the coolant is the iodide form. The content of iodate ions is 1–2% at an ammonia concentration of 18 to 79 mg/kg. The fraction of volatile organic and inorganic forms of iodine radionuclides passing into the gas phase from the coolant does not exceed 3.3 × 10–2 and 2.5 × 10–4%, respectively.
      PubDate: 2022-04-01
       
  • Subsequent Separation of Niobium (Nb), Thorium (Th), Rare Earth Elements
           (REEs), Zirconium (Zr), and Uranium (U) from Abu Rusheid Cataclastic
           Concentrate, South Eastern Desert, Egypt

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      Abstract: ataclastic rocks of Abu Rusheid area, Southeastern Desert of Egypt, were physically upgraded to obtain with producing a concentrate assaying 29.4% ZrO2, 1.55% Nb2O5, 3.13% RE2O3, 0.9% U3O8, and 0.66% ThO2. The corresponding minerals of these elements in the sample studied include zircon, columbite, samarskite, and uranothorite. Cassiterite is considered as an accessory mineral. The novelty of the suggested procedure is based on selective separation of niobium first from the aqueous liquor of the hydrous oxide cake obtained after alkali breakdown of the concentrate, leaving U, Th, Zr, and REEs in the residue. About 97% of niobium was selectively dissolved under the optimum conditions: weight ratio of concentrate sample to NaOH/KOH mixture 1 : 1.5, fusion time 2 h, and fusion temperature 500°C. This was followed by the recovery of Th, Zr, U, and REEs from the residue. The residue was treated with hydrochloric acid to achieve 98% leaching efficiency. From the two adequately obtained leach liquors, significant products have been prepared.
      PubDate: 2022-04-01
       
  • Radiocomplexation and Biological Evaluation of [99mTc]Tricarbonyl
           Rabeprazole as a Radiotracer for Peptic Ulcer Localization

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      Abstract: The radiotracer [99mTc]tricarbonyl Rabeprazole was successfully prepared using the [99mTc]tricarbonyl precursor. The reaction conditions were optimized (200 µg/2 mL substrate concentration, pH 8, incubation temperature 100°C, 30 min) to achieve the maximum radiochemical purity of 98%. Thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC) were used to assess the radiochemical purity and quality control parameters. A biodistribution study was also conducted to evaluate the biological biodistribution of [99mTc]tricarbonyl Rabeprazole in three different groups of mice models, with the normal group serving as the control and the second and third groups being microbial and chemically induced stomach ulcer disease models, respectively. The radiotracer [99mTc]tricarbonyl Rabeprazole complex was administered intravenously into mice via the tail vein and dissected at predefined time intervals. The biodistribution data demonstrated that the maximum absorption of [99mTc]tricarbonyl Rabeprazole complex in the stomach of normal mice and microbially and chemically induced ulcerated mice were 9.5, 35.3, and 23.7% ID/g tissue at 1 h post injection, respectively. The outcomes of the research show that [99mTc]tricarbonyl Rabeprazole can be used as a promising imaging agent to diagnose stomach ulcers.
      PubDate: 2022-04-01
       
  • Terbium Isotopes in Nuclear Medicine: Production, Recovery, and
           Application

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      Abstract: Terbium has four short-lived radioactive isotopes with mass numbers 149, 152, 155, and 161, which are promising for use in various fields of nuclear medicine, but this topic is currently at the research stage. Nowadays, the conditions for the production and recovery of these carrier free isotopes from irradiated targets, and preclinical and clinical trials of radiopharmaceuticals based on these nuclides are being actively studied. The results of the relevant reports are systematized in the presented review, which makes it possible to determine the main achievements and directions of research on terbium isotopes to date.
      PubDate: 2022-04-01
       
  • Cast Stone Matrices Based on Basaltic Melt with Uranium-Bearing Silica Gel

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      Abstract: The distribution of uranium between different phases of cast stone matrices fabricated by fusion of basalt and uranium-bearing SiO2-based collectors was investigated. It was found that matrices created by fusion of basalt with SiO2 consist of glass, quartz, and spinel as the main phases. A study of the physicochemical properties of collectors based on 30 wt % UO2(NO3)2-bearing SiO2 showed that, after thermal treatment at a temperature of 973 K, they contain uranium only in the form of UO3. The uranium leaching in H2O from SiO2 after its thermal treatment, as well as from a basaltic melt with SiO2, was estimated.
      PubDate: 2022-04-01
       
  • The Role of Phytoplankton in Self-Purification of Water Bodies with
           Radionuclide Pollutants

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      Abstract: The review considers the participation of phytoplankton in the self-purification of water bodies from radionuclide pollutants. An assessment of the mobility of the main radionuclides in freshwater reservoirs was carried out and a scale was proposed for assessing the hazard of the main radionuclides in freshwater reservoirs. Based on this approach, it was determined that 129I, 237Np, 226Ra, and 79Se are potentially dangerous. An analysis of the diversity of phytoplankton communities in freshwater reservoirs contaminated with radionuclides was carried out, and literature data on the main mechanisms of radionuclide immobilization by phytoplankton biomass were systematized. The role of silt biomineralization in the long-term immobilization of radionuclides in bottom sediments was assessed.
      PubDate: 2022-04-01
       
  • Sorption Kinetics of 60Co with Termoxid 35 Composite Sorbent in the
           Presence of Humic Acids

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      Abstract: The sorption kinetics of microamounts of Co(II) ions by the Termoxid 35 sorbent in a constant ionic strength chloride–acetate solution with and without the presence of natural humic acids (HAs) was studied using the finite volume method with sorbate recirculation. Detailed data on the real-time sorption of the 60Co radionuclide by the sorbent were obtained based on the rate of solution passing through the sorbent, pH, temperature, and HA concentration. The mixed-diffusion model of the Co(II) sorption kinetics, which includes successive stages of film and gel diffusion in the macro-micropores of the sorbent grain, the most statistically accurately and adequately simulates the data obtained. The coefficients of film (β, m/s) and gel (Dg, m2/s) diffusion do not depend on solution pH and HA concentration. The average value of Dg is (6.0 ± 4.5) × 10–10 m2/s, the activation energy of gel diffusion is 20.7 ± 10.0 kJ/mol at pH 7.5. The found values ​​are close to the Co2+ self-diffusion parameters in ultradilute aqueous solutions. A conclusion was made about the possibility of efficient sorption of Co(II) from natural aqueous solutions by the Termoxid 35 sorbent in the presence of humic acids.
      PubDate: 2022-04-01
       
  • Influence of the Structure of Biscarbamoylmethylphosphine Oxides on the
           Extraction of REE(III), U(VI), and Th(IV) from Nitric Acid Solutions in
           the Presence of an Ionic Liquid

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      Abstract: It was established that the extraction ability of bis[(diphenylphosphinyl)acetamido]alkanes, in the molecules of which two bidentate fragments Ph2P(O)CH2C(O)NAlk– are linked via an amide nitrogen atom by an alkylene bridge, with respect to REE(III), U(VI ) and Th(IV) in nitric acid media increases significantly in the presence of 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ionic liquid in the organic phase and significantly exceeds that of diaryl(dialkylcarbamoylmethyl)phosphine oxides. The stoichiometry of extractable REE(III) complexes was determined by the equilibrium shift method. The influence of the structure of the extractant and the concentration of HNO3 in the aqueous phase on the efficiency of the transition of REE(III), U(VI), and Th(IV) ions into an organic phase containing an ionic liquid is considered.
      PubDate: 2022-04-01
       
  • Structure of the XPS Spectra of a ThO2 Crystal Film

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      Abstract: The complex structure of precision X-ray photoelectron spectra (XPS) of valence and core electrons of a ThO2(001) crystal film on Si(100) was obtained and analyzed, and the electronic structure of ThO8, Th13O56, and Th63O216 clusters was calculated. A histogram of the calculated XPS spectrum of electrons of the outer (from 0 to ~15 eV, OVMO) and inner (from ~15 to ~35 eV, IVMO) valence MOs was plotted. The calculated spectrum was in good agreement with the experimental one. Significant overlap of Th 6d atomic orbitals (AO) as well as Th 6p, 5f AO with oxygen orbitals is noted, which brings about the covalent nature of the bond in this dioxide. The contribution of the OVMO and IVMO electrons to the chemical bond was estimated based on the values of the bond populations. It was shown that the IVMO electrons weaken the chemical bond caused by OVMO electrons. It is assumed that the complex structure in the spectra of the Th 5s and Th 5p electrons is largely due to the dynamic effect, which does not allow observing the structure in the spectrum of the Th 5s electrons in ThO2.
      PubDate: 2022-04-01
       
  • Geochemical Characterizations and Spectrometric Prospecting of the
           Arabian-Nubian Shield: A Сase Study from Abu Rusheid Area, South Eastern
           Desert of Egypt

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      Abstract: Abu Rusheid area is a part of the Arabo-Nubian basement exposures and is located in the southern Eastern Desert of Egypt, 95 km southwest of Marsa Alam City on the Red Sea coast. The Precambrian basement rocks include (a) ophiolitic metagabbros, (b) ophiolitic mélange, (c) mylonitic rocks, and (d) granites which were later intruded by lamprophyre dikes, pegmatite, and quartz veins. Geochemical studies revealed that both the mica schist and mylonite are mainly arkoses to greywacke in composition and confined to the passive margin tectonic setting. Chondrite-normalized REE patterns illustrate enrichment in HREEs in mica schist relative to LREEs, and there is a balance between them in mylonite. The minerals that have been identified in both mica schist and mylonite are soddyite, uranophane, kasolite, metazeunerite, thorite, uranothorite, and zinnwaldite. These mineralizations are related to shear zones and mainly coincide with the Najd fault (left lateral strike-slip) shear system. Field spectrometric measurements revealed that the average eU is 219 ppm and eTh is 451 ppm along trenches, whereas along channel samples the average eU is 64 ppm and eTh is 271 ppm.
      PubDate: 2022-04-01
       
  • Studies for Ultimate Uranium Separation from Its Low-Content Carbonate
           Leachate Solutions by Ion Flotation

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      Abstract: The research is aimed at removing uranium from low uranium content solutions using the ion flotation technique. The ion flotation process is an excellent technique for uranium separation from its solutions with low content or trace levels of uranium after optimizing carbonate–bicarbonate concentration for such solutions. It can also be applied to collecting uranium efficiently from all raffinates of the uranium separation or purification projects involving low-grade ore instead of other conventional long tedious methods such as ion exchange or solvent extraction, especially at low U levels. In this study, cetyltrimethylammonium bromide was used as a collector. The factors that can affect the flotation process (uranium concentration, gas flow rate, concentration of collector, and flotation time) were studied, and the best conditions were chosen: uranium concentration 0.02 g/L, carbonate concentration 10 g/L, gas flow rate 52 cm3/min, collector concentration 5 × 10–4 M, ethanol concentration 0.2% v/v, and flotation time 40 min. Under these conditions, the uranium flotation percentage reached more than 99%. A sample representing a sandy carbonaceous rock of Allouga area, southwestern Sinai, was prepared for alkaline leaching of uranium because of the high content of the carbonate which will consume large amounts of acids. The results of the experiments have shown that the optimum Na2CO3/NaHCO3 ratio is 1/1 at a total concentration of 80 g/L and S/L = 1/2, with 4-h agitation at room temperature. Under these conditions, the uranium leaching efficiency reached 94.2%, and the leachability increased to 98.7% at 80°C. The produced carbonate alkaline uranium-bearing leachate was subjected to the flotation process. A simplified sketch for the uranium separation from the carbonate solutions with a cationic collector is presented.
      PubDate: 2022-04-01
       
  • Sorption of Actinides in Various Oxidation States on TODGA-Containing TVEX
           from Nitric, Hydrochloric, and Perchloric Acid Media

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      Abstract: The static capacity (SC) of the AXIONIT MND40T grade solid extractant (TVEX) based on a macroporous styrene-divinylbenzene copolymer and an extractant, tetraoctyldiglycol diamide (TOGDA), were determined during the sorption of actinide ions (Th, U, Np, and Pu) in various oxidation states in 3 M HNO3, HCl, HClO4 media. Despite the fact that a clear relationship between the SC value, the actinide oxidation state, and the type of acid was not found, in most cases there is the highest capacity of the sorbent in nitric acid solutions. In hydrochloric and perchloric acid media, the SC values, as a rule, decrease by several times. In general, the capacity of the AXIONIT MND40T sorbent decreases in the following order: An(IV) ˃ An(III) ˃ An(VI), where An is the actinide. The determination of the TODGA/An molar ratio in the solid phase of the sorbent showed that in all cases, except for the sorption of Pu(IV) from 3 M HNO3, the ratio was greater than 3, while in the REE(III) extraction with TODGA from nitric acid solutions, the molar ratio TODGA/metal at saturation was 3.
      PubDate: 2022-04-01
       
  • Kinetics of Np(V) Reduction with Carbohydrazide Catalyzed by Tc(VII) in
           the Presence of U(VI)

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      Abstract: The kinetics of Np(V) reduction with carbohydrazide in nitric acid medium in the presence of Tc(VII) and U(VI) ions was studied by spectrophotometry. The reduced form of Np(IV) is unstable in time: reverse oxidation occurs, which accelerates with increase in the Tc(VII) ion concentration and temperature. The rate of the reduction stage is significantly higher than the rate of reverse oxidation. The orders of both stages of the reaction were found for all components.
      PubDate: 2022-04-01
       
  • Investigation of Laser Selective Photoionization of 177mLu Isomer to
           Create a 177mLu/177Lu Generator

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      Abstract: The selectivity and efficiency of laser photoionization of the 177mLu nuclear isomer by a three-stage photoionization scheme of lutetium 5d6s2 2D3/2−5d6s6p4F05/2−5d6s7s4D3/2−(53375 cm–1)01/2 were studied for the first time using pulsed tunable narrow-band dye systems pumped by copper vapor lasers. The study was carried out in relation to the problem of developing a hospital-based autonomous generator of the 177Lu radionuclide.
      PubDate: 2022-01-01
       
  • Study of 90Y Sorption with Nanodiamonds as Potential Carriers in the
           Radiopharmaceutical Composition

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      Abstract: The sorption of 90Y with nanodiamond (ND) and oxidized nanodiamond (oxND) was studied for their subsequent application as part of radiopharmaceuticals for β-therapy in nuclear medicine. The sorption kinetics was studied as a function of pH and salt background of aqueous solutions. It was found that the optimal media for 90Y sorption are aqueous solutions with pH from 5 to 7, as well as 0.9% NaCl solution and phosphate-buffered saline therewith as shown the presence of a salt background has no significant effect on sorption. The study of the stability of 90Y conjugates with ND and oxND in a model biological medium (fetal bovin serum) demonstrated that desorption does not exceed 27% in 24 h for the studied ND samples.
      PubDate: 2022-01-01
       
  • Hydrolitic Stability of Aluminophosphate Glasses with Radioactive Waste
           Simulators under Gamma Irradiation

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      Abstract: The effect of γ-irradiation with a dose of 62 MGy on the stability in water of two types of sodium aluminophosphate glasses was studied: glasses of a simple composition (GS) containing only frame elements (O, Na, Al, Fe, P) and a modified one (GM) with the addition of simulators of radioactive waste components (Cr, Mn, Ni, Ru, La, U). Leaching was carried out at 25 and 90°C with water replacement on the 1st, 3rd, 10th, 14th, 21st, and 28th days from the experiment onset. The dissolution rate of glasses, normalized by the matrix elements (Na, Al, Fe, P), after irradiation remains unchanged or slightly decreases. The leaching rate of radionuclide simulators in the vast majority of cases decreases, but for Cr, Ni, and La in experiments at 90°C, it slightly rises. The temperature curve of glass leaching intensity is described by the Arrhenius formula. An increase in temperature from 25 to 90°C bring about an increase in the leaching rate of all elements from glass matrices both before and after irradiation by 0.5–1.5 orders of magnitude. For both experimental temperatures, the leaching rate of elements decreases with time, which is explained by the protective layer formation on the surface of the samples.
      PubDate: 2022-01-01
       
 
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