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https://www.readbyqxmd.com/read/28811573/simultaneous-separation-of-actinium-and-radium-isotopes-from-a-proton-irradiated-thorium-matrix
#1
Tara Mastren, Valery Radchenko, Allison Owens, Roy Copping, Rose Boll, Justin R Griswold, Saed Mirzadeh, Lance E Wyant, Mark Brugh, Jonathan W Engle, Francois M Nortier, Eva R Birnbaum, Kevin D John, Michael E Fassbender
A new method has been developed for the isolation of (223,224,225)Ra, in high yield and purity, from a proton irradiated (232)Th matrix. Herein we report an all-aqueous process using multiple solid-supported adsorption steps including a citrate chelation method developed to remove >99.9% of the barium contaminants by activity from the final radium product. A procedure involving the use of three columns in succession was developed, and the separation of (223,224,225)Ra from the thorium matrix was obtained with an overall recovery yield of 91 ± 3%, average radiochemical purity of 99...
August 15, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28799357/in-search-of-discrete-symmetry-violations-beyond-the-standard-model-thorium-monoxide-reloaded
#2
Malika Denis, Timo Fleig
We present an updated electron electric dipole moment (EDM) effective electric field of Eeff= 75.2 GV/cm and (229)Th magnetic hyperfine interaction constant A|| = -1266 MHz, the nucleon-electron scalar-pseudoscalar interaction constant WS = 106.0 kHz, and the molecule-frame static electric dipole moment D = -4.41 D for the Δ13 science state of ThO. The criticisms of the results from Fleig and Nayak [J. Mol. Spectrosc. 300, 16 (2014)] made in Skripnikov and Titov [J. Chem. Phys. 142, 024301 (2015)] are addressed and largely found to be unsubstantiated within the framework of the present approach...
December 7, 2016: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28795722/revisiting-the-bis-dimethylamido-metallocene-complexes-of-thorium-and-uranium-improved-syntheses-structure-spectroscopy-and-redox-energetics-of-c5me5-2an-nme2-2-an-th-u
#3
K A Erickson, B D Kagan, B L Scott, D E Morris, J L Kiplinger
The reaction of (C5Me5)2AnCl2 (An = Th, U) with 2.8 or 4 equivalents of LiNMe2, respectively, affords (C5Me5)2An(NMe2)2 in high yields. In addition to improved syntheses, the solid-state structures, voltammetric data, and UV-visible-NIR spectra for these classic actinide bis(dimethylamido) complexes are presented for the first time.
August 10, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28795718/thorium-copper-phosphides-more-diverse-metal-phosphorus-and-phosphorus-phosphorus-interactions-than-u-analogues
#4
Geng Bang Jin, Christos D Malliakas, Jian Lin
To explore the chemical analogy between thorium and heavier actinides in soft anionic environments, three new thorium phosphides (ThCuP2, β-ThCu2P2, and ThCu5P3) have been prepared through solid-state reactions using CuI as a reaction promoter. The structure of ThCuP2 can be described as a filled UTe2-type with both dimeric P2(4-) and monomeric P(3-) anions, in which Th is coordinated by eight P atoms in a bicapped trigonal prismatic arrangement and Cu is tetrahedrally coordinated by four P atoms. β-ThCu2P2 contains only P(3-) anions and is isostructural with BaCu2S2...
August 10, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28776193/calculating-the-radiological-parameters-used-in-non-human-biota-dose-assessment-tools-using-erica-tool-and-site-specific-data
#5
Maria Sotiropoulou, Heleny Florou, Georgios Kitis
The substantial complexity in ecosystem-radionuclide interactions is difficult to be represented in terms of radiological doses. Thus, radiological dose assessment tools use typical exposure situations for generalized organisms and ecosystems. In the present study, site-specific data and radioactivity measurements of terrestrial organisms (grass and herbivore mammals) and abiotic components (soil) are provided. The retrieved data are used in combination with the ERICA Assessment Tool for calculation of radiological parameters...
August 3, 2017: Radiation and Environmental Biophysics
https://www.readbyqxmd.com/read/28760388/baseline-evaluation-for-natural-radioactivity-level-and-radiological-hazardous-parameters-associated-with-processing-of-high-grade-monazite
#6
E M El Afifi, A M Shahr El-Din, R F Aglan, E H Borai, M M Abo-Aly
Egyptian monazite is a promising resource and investment attractive for production of valuable metals of industrial or nuclear interest such as rare earth elements (REEs), thorium (Th) and uranium (U). The study was focused to establish a baseline framework in viewpoint of radiation protection for the workers in production of REEs from high-grade monazite treated by sodium hydroxide (NaOH) solutions. Radiological hazard indices (cancer, gonadal and other risks) were evaluated, due to emissions (α-, β- and γ-radiations) of radium-isotopes ((228)Ra, (226)Ra, (223)Ra) and lead ((210)Pb)...
July 29, 2017: Regulatory Toxicology and Pharmacology: RTP
https://www.readbyqxmd.com/read/28735687/on-the-sequential-separation-and-quantification-of-237-np-241-am-thorium-plutonium-and-uranium-isotopes-in-environmental-and-urine-samples
#7
M Vasile, K Jacobs, M Bruggeman, K Van Hoecke, A Dobney, F Verrezen
The implementation of the one-pass-through separation technique using two stacked chromatography columns of TEVA - TRU resins for the separation of (237)Np, (241)Am, thorium, plutonium and uranium from environmental and urine samples was investigated. The sequential separation technique proved to be successful and gave similar results to those obtained when using individual separations. The analysis time was considerably improved. The amount of chemical waste was also reduced by 50% and the use of HClO4 was avoided...
July 13, 2017: Applied Radiation and Isotopes
https://www.readbyqxmd.com/read/28724245/radioactively-hot-particles-detected-in-dusts-and-soils-from-northern-japan-by-combination-of-gamma-spectrometry-autoradiography-and-sem-eds-analysis-and-implications-in-radiation-risk-assessment
#8
Marco Kaltofen, Arnie Gundersen
After the March 11, 2011, nuclear reactor meltdowns at Fukushima Dai-ichi, 180 samples of Japanese particulate matter (dusts and surface soils) and 235 similar U.S. and Canadian samples were collected and analyzed sequentially by gamma spectrometry, autoradiography, and scanning electron microscopy with energy dispersive X-ray analysis. Samples were collected and analyzed over a five-year period, from 2011 to 2016. Detectable levels of (134)Cs and (137)Cs were found in 142 of 180 (80%) Japanese particulate matter samples...
July 15, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28723924/a-context-for-the-last-neandertals-of-interior-iberia-los-casares-cave-revisited
#9
Manuel Alcaraz-Castaño, Javier Alcolea-González, Martin Kehl, Rosa-María Albert, Javier Baena-Preysler, Rodrigo de Balbín-Behrmann, Felipe Cuartero, Gloria Cuenca-Bescós, Fernando Jiménez-Barredo, José-Antonio López-Sáez, Raquel Piqué, David Rodríguez-Antón, José Yravedra, Gerd-Christian Weniger
INTRODUCTION AND OBJECTIVES: Although the Iberian Peninsula is a key area for understanding the Middle to Upper Paleolithic transition and the demise of the Neandertals, valuable evidence for these debates remains scarce and problematic in its interior regions. Sparse data supporting a late Neandertal persistence in the Iberian interior have been recently refuted and hence new evidence is needed to build new models on the timing and causes of Neandertal disappearance in inland Iberia and the whole peninsula...
2017: PloS One
https://www.readbyqxmd.com/read/28699737/extending-the-use-of-highly-porous-and-functionalized-mofs-to-th-iv-capture
#10
Nan Zhang, Li-Yong Yuan, Wen-Lu Guo, Shi-Zhong Luo, Zhi-Fang Chai, Wei-Qun Shi
Thorium separation has recently become a hot topic because of the potential application of thorium as a future nuclear fuel, while metal-organic framework (MOF) materials have received much attention in the separation field due to their unique properties. Herein, a highly porous and stable MOF, UiO-66, and its carboxyl derivatives (UiO-66-COOH and UiO-66-(COOH)2) were synthesized and explored for the first time for Th(IV) capture from a weak acidic solution. Although the introduction of carboxyl groups into UiO-66 leads to an obvious decrease in the surface area and pore volume, the adsorbability toward Th(IV) is greatly enhanced...
July 19, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28689881/comparison-of-radium-228-determination-in-water-among-australian-laboratories
#11
Atun Zawadzki, Megan Cook, Brodie Cutmore, Fiona Evans, Daniela Fierro, Alicea Gedz, Jennifer J Harrison, Tom Loosz, Peter Medley, Lida Mokhber-Shahin, Sarah Mullins, Sandra Sdraulig
The National Health and Medical Research Council and Natural Resource Management Ministerial Council of Australia developed the current Australian Drinking Water Guidelines which recommend an annual radiation dose value of 1 mSv year(-1). One of the potential major contributors to the radiation dose from drinking water is radium-228, a naturally occurring radionuclide arising from the thorium decay series. Various methods of analysing for radium-228 in water have been established and adapted by analytical radiochemistry laboratories...
July 6, 2017: Journal of Environmental Radioactivity
https://www.readbyqxmd.com/read/28688249/use-of-spectral-gamma-ray-as-a-lithology-guide-for-fault-rocks-a-case-study-from-the-wenchuan-earthquake-fault-scientific-drilling-project-borehole-4-wfsd-4
#12
Ahmed Amara Konaté, Heping Pan, Huolin Ma, Zhen Qin, Bo Guo, Yao Yevenyo Ziggah, Claude Ernest Moussounda Kounga, Nasir Khan, Fodé Tounkara
The main purpose of the Wenchuan Earthquake Fault Scientific drilling project (WFSD) was to produce an in-depth borehole into the Yingxiu-Beichuan (YBF) and Anxian-Guanxian faults in order to gain a much better understanding of the physical and chemical properties as well as the mechanical faulting involved. Five boreholes, namely WFSD-1, WFSD-2, WFSD-3P, WFSD-3 and WFSD-4, were drilled during the project entirety. This study, therefore, presents first-hand WFSD-4 data on the lithology (original rocks) and fault rocks that have been obtained from the WFSD project...
June 28, 2017: Applied Radiation and Isotopes
https://www.readbyqxmd.com/read/28678261/thorium-complexes-possessing-expanded-ring-n-heterocyclic-iminato-ligands-synthesis-and-applications
#13
Tapas Ghatak, Shani Drucker, Natalia Fridman, Moris S Eisen
Six and seven membered N-heterocyclic iminato ligands (L) are introduced allowing access a new class of Th(iv) complexes of the type Cp*2Th(L)(CH3). These complexes were studied in the Tishchenko reaction. Stoichiometric reactions together with kinetic and thermodynamic studies permit us to propose a plausible mechanism.
July 5, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28668731/determination-of-thorium-iv-using-isophthalaldehyde-tetrapyrrole-as-probe-by-resonance-light-scattering-second-order-scattering-and-frequency-doubling-scattering-spectra
#14
Jiao Wang, Jinhua Xue, Xilin Xiao, Li Xu, Min Jiang, Pengcheng Peng, Lifu Liao
The coordination reaction of thorium (IV) with a ditopic bidentate ligand to form supramolecular polymer was studied by resonance light scattering (RLS) spectra, second-order scattering (SOS) spectra and frequency-doubling scattering (FDS) spectra, respectively. The ditopic bidentate ligand is isophthalaldehyde-tetrapyrrole (IPTP). It was synthesized through a condensation reaction of isophthalaldehyde with pyrrole. The formation of supramolecular polymer results in remarkable intensity enhancements of the three light scattering signals...
June 27, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28649867/study-of-isotopes-of-carbon-thorium-and-uranium-in-travertine-and-thermal-spring-samples-implications-for-effects-of-changes-in-geochemical-environment-and-processes
#15
Alexander I Malov
Data on modern radiocarbon activity in the old travertine formations of the Pymvashor hydrothermal system were used, in combination with (230)Th/U dating of the travertine, to estimate the (14)C contents of the total dissolved inorganic carbon in the ancient thermal water at the time of precipitation of the travertine ((14)Ccalc). With the known values of (14)Ccalc and average age of the thermal water, and under the assumption that the residence time of the water in aquifer was constant over the last 13.9 ± 1...
June 26, 2017: Isotopes in Environmental and Health Studies
https://www.readbyqxmd.com/read/28628886/estimation-of-the-production-of-medical-ac-225-on-thorium-material-via-proton-accelerator
#16
Ozan Artun
In the present study, we aimed at estimating the production of medical Ac-225 radionuclide via proton accelerator in the energy range Eproton=1000 →1MeV under certain conditions, on thorium target material instead of uranium due to the low abundant of uranium in nature. Hence, to produce the medical Ac-225, cross-section, separation energy was calculated by taking into account the proton induced reaction processes that were simulated to estimate activity and, yield of the product up to 1000MeV. Moreover, the calculated integral yields of reactions were presented...
June 10, 2017: Applied Radiation and Isotopes
https://www.readbyqxmd.com/read/28537586/actinide-covalency-measured-by-pulsed-electron-paramagnetic-resonance-spectroscopy
#17
Alasdair Formanuik, Ana-Maria Ariciu, Fabrizio Ortu, Reece Beekmeyer, Andrew Kerridge, Floriana Tuna, Eric J L McInnes, David P Mills
Our knowledge of actinide chemical bonds lags far behind our understanding of the bonding regimes of any other series of elements. This is a major issue given the technological as well as fundamental importance of f-block elements. Some key chemical differences between actinides and lanthanides-and between different actinides-can be ascribed to minor differences in covalency, that is, the degree to which electrons are shared between the f-block element and coordinated ligands. Yet there are almost no direct measures of such covalency for actinides...
June 2017: Nature Chemistry
https://www.readbyqxmd.com/read/28528235/mapping-natural-radioactivity-of-soil-samples-in-different-regions-of-punjab-india
#18
Komal Saini, B S Bajwa
Thallium activated sodium iodide (NaI(Tl)) detector and multi channel analyzer has been utilized to measure gamma rays emitted by radio nuclides found in soil samples of south-west (SW) region of Punjab state, India where elevated level of uranium of around value of 700µg/l in groundwater has been reported. For comparative study, soil samples were also collected and analyzed from west (W) and north east (NE) regions of the state. Uranium and potassium has been found to be comparatively higher in SW region whereas thorium level is higher in W and NE part of Punjab state...
May 13, 2017: Applied Radiation and Isotopes
https://www.readbyqxmd.com/read/28514699/profiling-of-illicit-cocaine-seized-in-china-by-icp-ms-analysis-of-inorganic-elements
#19
Cuimei Liu, Zhendong Hua, Xin Meng
For the first time in China, the inorganic element profiling of cocaine specimens was performed at the National Narcotics Laboratory. An inductive coupled plasma-mass spectrometry (ICP-MS) method was developed and validated for simultaneous analysis of 26 inorganic elements, including sodium (Na), magnesium (Mg), aluminuim (Al), potassium (K), calcium (Ca), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), selenium (Se), molybdenum (Mo), silver (Ag), cadmium (Cd), antimony (Sb), barium (Ba), lanthanum (La), cerium (Ce), thallium (Tl), lead (Pb), thorium (Th), and uranium (U) in illicit cocaine samples...
April 29, 2017: Forensic Science International
https://www.readbyqxmd.com/read/28511933/an-initial-demonstration-of-hierarchically-porous-niobium-alkylphosphonates-coordination-polymers-as-potent-radioanalytical-separation-materials
#20
Kai Lv, Chu-Ting Yang, Jun Han, Sheng Hu, Xiao-Lin Wang
Combining the merits of soft-templating and perchlorate oxidation methods, the first-case investigation of niobium alkylphosphonates has uncovered their unique morphology, backbone composition, thermal behavior and huge potentiality as radioanalytical separation materials. These hierarchically porous solids are random aggregates of densely stacked nanolayers perforated with worm-like holes or vesicular voids, manifesting the massif-, tower-like "polymer brush" elevated up to ∼150nm driven by the minimal surface free energy principle...
May 8, 2017: Journal of Chromatography. A
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