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Ghasem Sargazi, Daryoush Afzali, Ali Mostafavi
Reverse micelle (RM) and ultrasound assisted reverse micelle (UARM) were applied to the synthesis of novel thorium nanostructures as metal organic frameworks (MOFs). Characterization with different techniques showed that the Th-MOF sample synthesized by UARM method had higher thermal stability (354°C), smaller mean particle size (27nm), and larger surface area (2.02×10(3)m(2)/g). Besides, in this novel approach, the nucleation of crystals was found to carry out in a shorter time. The synthesis parameters of UARM method were designed by 2(k-1) factorial and the process control was systematically studied using analysis of variance (ANOVA) and response surface methodology (RSM)...
March 2018: Ultrasonics Sonochemistry
Shuhua He, Mumei Chen, Zheng Li, Haixia Cong, Lan Zhang, Qinnuan Li
For the determination of μg-mg L(-1) of FPs in 100 g L(-1) of thorium matrix with HCl medium, a method, including anion-exchange pre-separation, evaporation and inductively coupled plasma mass spectrometry (ICP-MS) measurement, was developed. The procedure parameters, such as the matrix effect of thorium, the acidity of separation, the elution curve of thorium and FPs and the temperature of evaporation were optimized by batch equilibration, column elution and evaporation experiments. It was found that the average recovery of the FPs was in the range 80 - 110%, and the RSD values were in the range 2 - 15% utilizing prior anion exchange separation of FPs from thorium samples...
2017: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
Jian Lin, Meiying Qie, Linjuan Zhang, Xiaomei Wang, Yuejian Lin, Wei Liu, Hongliang Bao, Jianqiang Wang
Systematic control of the molar ratio between thorium hydroxides and selenic acid and their reaction temperature under hydrothermal conditions results in four novel thorium-based selenate complexes, namely, [Th8O4(OH)8(SeO4)6(H2O)16]·(SeO4)2·13H2O (Th-1), [Th8O4(OH)8(SeO4)8(H2O)13]·7H2O (Th-2), Th(OH)2(SeO4)H2O (Th-3), and Th3(SeO4)6(H2O)6·2.5H2O (Th-4), as well as the thorium mixed selenite selenate compound Th(SeO3)(SeO4) (Th-5). Smaller [H2SeO4]/[Th(IV)] ratio or lower temperature give rise to the formation of octameric [Th8(μ3-O)4(μ2-OH)8](16+) cores in Th-1/Th-2 and infinite [Th(μ2-OH)2H2O](2+) chains in Th-3, respectively...
November 8, 2017: Inorganic Chemistry
Yuxiang Li, Zaixing Yang, Yanlong Wang, Zhuanling Bai, Tao Zheng, Xing Dai, Shengtang Liu, Daxiang Gui, Wei Liu, Meng Chen, Lanhua Chen, Juan Diwu, Lingyan Zhu, Ruhong Zhou, Zhifang Chai, Thomas E Albrecht-Schmitt, Shuao Wang
Many environmental pollutants inherently exist in their anionic forms and are therefore highly mobile in natural water systems. Cationic framework materials that can capture those pollutants are highly desirable but scarcely reported. Here we present a mesoporous cationic thorium-based MOF (SCU-8) containing channels with a large inner diameter of 2.2 nm and possessing a high surface area of 1360 m(2) g(-1). The anion-exchange properties of SCU-8 were explored with many anions including small oxo anions like ReO4(-) and Cr2O7(2-) as well as anionic organic dyes like methyl blue and the persistent organic pollutant, perfluorooctane sulfonate (PFOS)...
November 7, 2017: Nature Communications
Wellington Marcos da Silva, Tiago Hilário Ferreira, Carlos Antônio de Morais, Alexandre Soares Leal, Edésia Martins Barros Sousa
Boron nitride nanotubes doped in situ with samarium (Sm-doped BNNTs) were synthesized at 1150°C under atmosphere of NH3/N2 gas mixture by thermal chemical vapor deposition (TCVD) using samarium oxide that is a product of the process separation of thorium and uranium tailings. The samarium in the BNNTs sample was activated by neutron capture, in a nuclear reactor, producing (152)Sm radioisotopes. The STEM-EELS spectrum and neutron activation show energies attributed to the samarium confirming the in situ doping process during BNNTs growth...
October 31, 2017: Applied Radiation and Isotopes
Liie Lumiste Hill, Siiri Suursoo, Madis Kiisk, Alar Jantsikene, Nele Nilb, Rein Munter, Enn Realo, Rein Koch, Kaisa Putk, Maria Leier, Taavi Vaasma, Kadri Isakar
A drinking water treatment plant in Viimsi, Estonia was monitored over three years for iron, manganese, radium-226, radium-228, and their daughter nuclides in order to determine the efficiency of the treatment process, get an insight of the removal mechanisms and interactions between radium, iron, and manganese, and assess the overall longevity and performance of the technology and possible build-up of NORM from the treatment process. During the study, samples were collected from raw water, first and second stage filtrate, consumer water, backwash water, and filter materials...
November 3, 2017: Journal of Radiological Protection: Official Journal of the Society for Radiological Protection
Masanori Ogawa, Ryusuke Ae, Teppei Sasahara
In the current study, we report a case of a 46-year-old man who presented with sudden abdominal pain and was diagnosed with rupture of hepatic angiosarcoma (HAS). He underwent surgery, but died 13 days after the onset of the abdominal pain. Chronic exposure to carcinogens, such as thorium dioxide, arsenic, vinyl chloride, and radium, is associated with HAS. However, our patient had not been exposed to such carcinogens. He had submitted himself for annual medical checkups since he was employed. His liver was cirrhotic, and medical history data showed that he had had fatty liver for at least 10 years before HAS onset...
September 2017: Case Reports in Oncology
Shane S Galley, Cayla E Van Alstine, Laurent Maron, Thomas E Albrecht-Schmitt
The reaction of Th(NO3)4·5H2O with 3 equiv of 2,2',6',2″-terpyridine (terpy) in a mixture of acetonitrile and methanol results in formation of the trinuclear thorium peroxide cluster [Th(O2)(terpy)(NO3)2]3. This cluster is assembled via bridging by μ-η(2):η(2) peroxide anions between thorium centers. It decomposes upon removal from the mother liquor to yield Th(terpy)(NO3)4 and Th(terpy)(NO3)4(EtOH). The peroxide formation appears to be radiolytic in origin and is, most likely, generated from radiolysis of water by short-lived daughters generated from (232)Th decay...
November 6, 2017: Inorganic Chemistry
S Mvondo, G H Ben-Bolie, J M Ema'a Ema'a, P Owono Ateba, P Ele Abiama, J F Beyala Ateba
This study was carried out in the localities Melondo and Ngombas located in the Southern Region of Cameroon where there are known to be uranium-bearing and high background radiation areas. Activity concentrations of naturally occurring radionuclides (210)Po, (238)U, (235)U, (234)U, (232)Th, (230)Th, (228)Th and (226)Ra were determined in soil and fern (filicophyta) samples collected at 10 points in both localities. In soil, the average values of these activity concentrations (in d.w.) were (210)Po(130 ± 10), (238)U(126 ± 11...
October 21, 2017: Journal of Environmental Radioactivity
Rosa Pérez, Eva Doménech, Andrea Conchado, Alfredo Sanchez, Clara Coscollà, Vicent Yusà
Pollution by trace elements and its possible effect on organisms has become a worldwide concern due to the increasing presence of trace elements in the environment and especially in the food chain. Exposure to chemicals has traditionally been measured using environmental samples, however, human biomonitoring brings a different perspective, in which all sources and exposure pathways are integrated. The objective of this paper is to discern the possible relationship between children's diet and the metals found in children urine...
October 17, 2017: Science of the Total Environment
E E Hardy, K M Wyss, J D Gorden, I R Ariyarathna, E Miliordos, A E V Gorden
The synthesis, characterization, and electronic spectroscopy of two ML2 sandwich complexes, where M = Ce(iv) or Th(iv) and L = napthylsalophen(2-) are described. The ThL2 complex, unlike the isovalent CeL2, complex possesses unusual fluorescence properties in both solution and solid-state. These observations are explained with TD-DFT.
October 17, 2017: Chemical Communications: Chem Comm
Petr V Borisyuk, Sergey P Derevyashkin, Ksenia Y Khabarova, Nikolay N Kolachevsky, Yury Y Lebedinsky, Sergey S Poteshin, Alexey A Sysoev, Evgeny V Tkalya, Dmitry O Tregubov, Viktor I Troyan, Oleg S Vasiliev, Valery P Yakovlev, Valery I Yudin
We describe an original multisectional quadrupole ion trap aimed to realize nuclear frequency standard based on the unique isomer transition in thorium nucleus. It is shown that the system effectively operates on Th(+), Th(2+) and Th(3+) ions produced by laser ablation of metallic thorium-232 target. Laser intensity used for ablation is about 6 GW/cm(2). Via applying a bias potential to every control voltage including the RF one, we are able not only to manipulate ions within the energy range as wide as 1-500 eV but to specially adjust trap potentials in order to work mainly with ions that belong to energy distribution maximum and therefore to effectively enhance the number of trapped ions...
August 2017: European Journal of Mass Spectrometry
Petr V Borisyuk, Sergey P Derevyashkin, Ksenia Yu Khabarova, Nikolay N Kolachevsky, Yury Yu Lebedinsky, Sergey S Poteshin, Alexey A Sysoev, Evgeny V Tkalya, Dmitry O Tregubov, Viktor I Troyan, Oleg S Vasiliev, Valery P Yakovlev, Valery I Yudin
We consider an experiment on trapping and laser cooling of (229)Th(3+) ions in a linear Paul trap in the presence of undesirable impurities such as ions of the radioactive isotope (228)Th(3+). We suggest a method of separating these impurities by means of selective laser cooling utilizing the isotope shift of cooling transitions in (229)Th(3+) and (228)Th(3+) ions. According to our estimation, the isotope shift is equal to 3.4 GHZ and makes laser separation of these isotopes possible.
August 2017: European Journal of Mass Spectrometry
Justin Walensky, Sean P Vilanova, Patrick Huang, Pinar Alayoglu, Mohammad Heidarian
The complexes (C5Me5)2Th(EHTipp)2, (E = P or As, Tipp = 2,4,6-triisopropylphenyl), provide a ligand framework that results in facile access to rare Th-E multiple bonds. The reaction of (C5Me5)2Th(EHTipp)2 with KN(SiMe3)2, proceeds cleanly to the desired bridging phosphinidiide or arsinidiide complex, [{(C5Me5)2Th(μ2-ETipp(μ2-EHTipp)}K]2 under ambient conditions. In the absence of a chelating agent, the potassium cation of one monomeric unit interacts with the aryl ring of a second monomer to form a bridged dimer...
October 12, 2017: Chemistry: a European Journal
Tania Warnakulasuriya, Senani Williams, Mangala Dabarera, Kusum Rodrigo, Thiwanka Weerakkody, Rajitha Wickremasinghe
Lanka Mineral Sands Ltd (LMS), a government-owned company, has been mining mineral sands including monazite which contains thorium (Th) at Pulmoddai, Sri Lanka since 1957. Th emits alpha particles on decay and gamma rays are emitted by the daughter products. The cytokinesis-blocked micronucleus (MN) assay is popular for large scale radiation exposure studies as it is an easy, fast and reliable method of biodosimetry. The objective of the study was to determine the frequency of micronuclei among persons residing in the vicinity of LMS...
August 29, 2017: Mutagenesis
Yaxing Wang, Tao Duan, Zhehui Weng, Jie Ling, Xuemiao Yin, Lanhua Chen, Daopeng Sheng, Juan Diwu, Zhifang Chai, Ning Liu, Shuao Wang
f-element-bearing iodate compounds are a large family mostly synthesized by hydrothermal reactions starting with actinide/lanthanide ions and iodic acid or iodate salt. In this work, we introduce melting periodic acid flux as a new reaction medium and provide a safe way for single-crystal growth of a series of new f-element iodate compounds including UO2(IO3)2·H2O (1), UO2(IO3)2(H2O)·HIO3 (2), α-Th(IO3)2(NO3)(OH) (3), β-Th(IO3)2(NO3)(OH) (4), and (H3O)9Nd9(IO3)36·3HIO3 (5). The structures of these compounds deviate from those afforded from hydrothermal reactions...
November 6, 2017: Inorganic Chemistry
A K Visnuprasad, G Jaikrishnan, B K Sahoo, C E Pereira, P J Jojo
In an environment having thorium rich soil the activity concentration of thoron in soil gas and ground-level outside air is comparable to that to radon. Recent reports indicate that in terms of the energy of the alpha particle decays of thoron's progeny, its concentration in indoor air is significant, typically about half that due to radon progeny. We made a detailed radiometric profiling of inhalation dose to the population of the high background radiation area in the west southern coastal region of India...
September 15, 2017: Radiation Protection Dosimetry
Florian Lahrouch, Oleksandr Sofronov, Gaëlle Creff, André Rossberg, Christoph Hennig, Christophe Den Auwer, Chirstophe Di Giorgio
The use of uranium and to a minor extent plutonium as fuel for nuclear energy production or as components in military applications is under increasing public pressure. Uranium is weakly radioactive in its natural isotopy but its chemical toxicity, combined with its large scale industrial utilization, makes it a source of concern in terms of health impact for workers and possibly the general population. Plutonium is an artificial element that exhibits both chemical and radiological toxicities. So far, uranium (under its form uranyl, U(vi)) or plutonium (as Pu(iv)) decorporation or protecting strategies based on molecular design have been of limited efficiency to remove the actinide once incorporated after human exposure...
October 17, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
J A Suarez-Navarro, Ll Pujol, M J Suarez-Navarro
The indicative dose (ID) is one of the parameters established in the current European directive for water intended for human consumption. To determine the ID, it is necessary to know the activity concentration of: (238)U, (234)U, (226)Ra, (210)Po, (239,240)Pu and (241)Am. The existing methods to determine these radionuclides involve complex radiochemical separations (ionic exchange columns, extraction chromatography, etc.), followed by measurements with a semiconductor detector, laboratory procedures that are time-consuming and costly...
September 23, 2017: Applied Radiation and Isotopes
Vinay Jain, Divyalakshmi Saini, P R Vivek Kumar, G Jaikrishan, Birajalaxmi Das
High level natural radiation areas (HLNRA) of Kerala coastal strip (55km long and 0.5km wide) in southwest India exhibit wide variations in the level of background dose (< 1.0-45.0mGy/year) due to thorium deposits in the beach sand. The areas with ≤1.5mGy/year are considered as normal level natural radiation area (NLNRA), whereas areas with >1.5mGy/year are HLNRA. Individuals belonging to HLNRA were stratified into two groups, Low dose group (LDG: 1.51-5.0mGy/year) and high dose group (HDG: >5.0mGy/year)...
September 20, 2017: Mutation Research
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