Authors:S. M. Jeong, S.-B. Park, S.-S. Hong, C.-S. Seo, and S.-W. Park
electrolytic reduction of U3O8 powder was carried out
using LiCl-Li2O molten salt in a 20-kg U3O8
batch cell to verify the feasibility of the process. As the current passes the
cell, the decomposition of Li2O and the reduction of U3O8
occur simultaneously in a cathode assembly and oxygen gas evolvs at the anode.
The results from a 20-kg U3O8 scale cell were compared
with data obtained from a bench scale cell. The results suggest a successful
demonstration of this process, exhibiting a reduction conversion of U3O8
of more than 99% in a batch.
Trace elements in airborne particulate matter collected monthly at suburban and rural areas in Korea were analyzed by instrumental neutron activation analysis (INAA). Neutron irradiation of the samples was done at the irradiation hole (neutron flux 1·1013 n·cm–2·s–1) of the TRIGA Mark-III Research Reactor in the Korea Atomic Energy Research Institute. For the verification of the analytical technique, two reference materials, NIST SRM-1648 and NIES CRM-8, were chosen for analysis. The accuracy and precision of the determinations of the 40 elements were compared with the reference values. We used this method (1) to analyze 30 trace elements in airborne particulate matter collected monthly with the high volume air sampler (PM-10) at two different locations and (2) to confirm the possibility of using this method as a routine monitoring tool to find out environmental pollution sources.
Authors:K. Lee, Y. Yoon, S. Jeong, Y. Chae, and K. Ko
The effects of acids on the removal of impurity from 2N grade silica have been studied using five leaching acids: 0.2 M-oxalic
acid (pH 1.5 and 2.5), c-aqua regia, 2.5%—HCl/HF, and 1%—HNO3/HF. The presence of 39 impurities in the 2N grade silica and the reference material (RM, 5N grade silica) were investigated
by neutron activation analysis (NAA), X-ray fluorescence (XRF), and inductively coupled plasma mass spectrometry (ICP-MS)
methods. Major impurities of the 2N silica were Al, K, Fe, Na, Ti, Ca, Mg and P. The fractions of the eight major impurities
were 99.2% and 90.9% of total impurity in the 2N and RM silica, respectively. Among the leaching acids, almost all of the
major impurities were removed effectively by the 2.5% HCl/HF leaching acid. All the major impurities, except for phosphorous,
as well as 21 minor and trace impurities could be determined by the NAA.
Authors:B. H. Park, S. B. Park, S. M. Jeong, C.-S. Seo, and S.-W. Park
The Advanced Spent Conditioning Process (ACP) developed by the KAERI is based on pyrometallurgy and the electrolytic reduction
plays a central role in transforming spent oxide fuels into metals. The constituents of the spent fuels are distributed between
a salt and a reduced metal phase during electrolysis. Lithium metal is produced in a molten LiCl-Li2O cell and then it reacts with the metal oxides of the spent fuel producing Li2O and reduced metals. By focusing on the activity of Li2O and the electric potential, the electrolytic reduction process of the ACP is discussed. Thermodynamic considerations are
defined and operation conditions are proposed including Li2O activity and cell potential.
Authors:S. Kondratyuk, L. Lőkös, J. Kim, M.-H. Jeong, A. Kondratiuk, S.-O. Oh, and J.-S. Hur
The new genus Kashiwadia S. Y. Kondr., L. Lőkös et J.-S. Hur, gen. nov. for the Eastern Asian species Physcia orientalis Kashiw. being in isolated position in the genus Physcia after morphological and anatomical characters as well as showing closer relation to the Heterodermia branch (than to the Physcia branch) in phylogenetic tree of the Physciaceae based on results of ITS1/ITS2 nuclear ribosomal and positioning in separate branch after 12S SSU mitochondrial DNA sequences and combined data set is proposed. Description of new genus and new combination is provided.
Authors:S. Kondratyuk, L. Lőkös, J. Kim, A. Kondratiuk, M.-H. Jeong, B. Zarei-Darki, and J.-S. Hur
The new genus Oxnerella is proposed for the lichen similar to Iranian endemic species Lecania ochronigra J. Steiner. Its isolated position in the phylogenetic tree after combined ITS nrDNA and 12S SSU mtDNA data set including members of the Ramalinaceae, Lecideaceae, Lecanoraceae and Megasporaceae is discussed. Description of the new species Oxnerella safavidiorum, comparison with allied taxa and illustrations is provided. The new combination Thamnolecania racovitzae (basionym: Lecanora racovitzae Vain.) is proposed.
Authors:S. Y. Kondratyuk, L. Lőkös, M.-H. Jeong, S.-O. Oh, A. S. Kondratiuk, and J.-S. Hur
Three genera new for science, i.e. Candelinella S. Y. Kondr. for the Candelariella makarevichiae group, Opeltiella S. Y. Kondr. for the Candelaria fraudans group, as well as Protocandelariella Poelt, D. Liu, J.-S. Hur et S. Y. Kondr. for the Candelariella subdeflexa group are proposed for robust monophyletic branches of the Candelariaceae on the basis of three-gene phylo- geny (i.e. concatenated nrITS, 12S mtSSU and 28S nrLSU sequences). Eight new combinations, i.e. Candelinella makarevichiae (for Candelariella makarevichiae S. Y. Kondr., L. Lokos et J.-S. Hur), Candelinella deppeanae (for Candelariella deppeanae M. Westb.), Opeltiella fraudans (for Candelaria fraudans Poelt et Oberw.), Opeltiella fibrosoides (for Candelaria fibrosoides M. Westb. et Froden), Opeltiella rubrisoli (for Candelariella rubrisoli D. Liu et J.-S. Hur), Opeltiella canadensis (for Candelariella canadensis H. Magn.), Protocandelariella subdeflexa (for Lecanora subdeflexa Nyl.), Protocandelariella blastidiata (for Candelariella blastidiata L. Yakovchenko) are provided.
Molecular data provided for Candelinella makarevichiae (including holotype and iso- type), as well as additional specimens of Candelaria asiatica from South Korea for the first time. The latter species (Candelaria asiatica) from China, as well as’Candelaria’ murrayi from Argentina, South America are recorded for the first time. Voucher of Candelariella vitellina from Antarctica is also identified based on molecular phylogeny. It is for the first time shown that ’Candelaria’murrayi is positioned in the outermost position to Candelaria s. str. branch of the phylogenetic tree of the Candelariaceae, and may belong to another genus. Status of the ’Candelariella’medians group, the’Candelariella’ placodizans group, as well as single species ’Candelariella’reflexa and’Candelaria’ pacifica, forming separate branches outside the Candelariella s. str. and Candelaria s. str. clades, will be clarified when additional molecular data will be accumulated. Candelariella subsquamulosa D. Liu et Hur, recently described from South Korea (Liu et al. 2019), proved to be a new synonym of Candelinella makarevichiae.
Authors:S. Kondratyuk, M.-H. Jeong, N.-H. Yu, I. Kärnefelt, A. Thell, J. Elix, J. Kim, A. Kondratyuk, and J.-S. Hur
Four new monophyletic groups are found within the teloschistoid clade of the subfamily Xanthorioideae in the Teloschistaceae using nuclear (ITS1/ITS2) and mitochondrial (12S mtSSU gene) DNA sequences. These groups are proposed as new genera: Brownliella gen. nova for the widely distributed Caloplaca cinnabarina group, Filsoniana gen. nova for the Australian Caloplaca australiensis group, Fulgogasparrea gen. nova for the Western Pacific species Caloplaca decipioides, and Kaernefia gen. nova for the Southern Hemisphere Caloplaca kaernefeltii group. Massalongo’s genus Niorma is resurrected for the Teloschistes hypoglaucus group.
Authors:S. Kondratyuk, M.-H. Jeong, N.-N. Yu, I. Kärnefelt, A. Thell, J. Elix, J. Kim, A. Kondratiuk, and J.-S. Hur
Seven strongly supported clades, characterised by molecular, morphological and anatomical characters are described as new genera: Eilifdahlia, Elenkiniana, Franwilsia, Huneckia, Marchantiana, Mikhtomia and Yoshimuria. Two new species, Eilifdahlia wirthii from South Africa and Marchantiana maulensis from Chile are described, illustrated and compared with closely related taxa.
Authors:S. Kondratyuk, I. Kärnefelt, A. Thell, J. Elix, J. Kim, M.-H. Jeong, N.-N. Yu, A. Kondratiuk, and J.-S. Hur
The phylogeny of the subfamily Xanthorioideae (Teloschistaceae) is re-analysed based on ITS, LSU and mtSSU sequences, including a new set of specimens representing 31 genera, of which five are proposed as new: Golubkovia, Igneoplaca, Langeottia, Scythioria and Verrucoplaca. Two new species, Ovealmbornia volkmarwirthii from South Africa and Gondwania sejongensis from Antarctica are described, illustrated and compared with closely related taxa. Eleven new combinations are proposed in the genera Calogaya, Cerothallia, Flavoplaca, Gondwania, Igneoplaca, Scythioria and Verrucoplaca, but the status of four earlier established genera, Pachypeltis, Parvoplaca, Solitaria and Xanthopeltis, remains uncertain and needs further studies.