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Abstract  

This study aims to provide archiving research trends from the perspective of the field of library and information science using profiling analysis method. The LISA database has been selected as the representative database in the library and information science field, and articles have been searched via the keyword ‘archiv*’. The analysis methods used in this study were the journal profiling method and the descriptor profiling method. The descriptor profiling method presents descriptors as a bag of words. That is, it represents descriptors according to the word sets which are included in the documents in which those descriptors are assigned. As a result of journal analysis, six representative journals which are closely related to archiv* have been identified. The six journals were Archivaria, Advanced Technology Libraries, Journal of the Society of Archivists, American Archivist, Archifacts, and Records Management Bulletin. The results of descriptor analysis show that the most comprehensive and core subject was digital libraries, and the most comprehensive and core object was the electronic media. Another result of detailed analysis shows that the outstanding objects were publications, special collections/sound, cultural heritage, television, image/photographs, internet/bibliographic data, and DB/newspapers. On the other hand, outstanding subjects were Archives, National Libraries, Universities, Libraries and companies.

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Abstract  

Chlorination reaction behavior of Zircaloy-4 hull waste was investigated by using HSC chemistry code as a function of decladding ratio. The Zircaloy-4 hull waste and residual spent nuclear fuel (SNF) remaining in the hull waste after oxidative decladding process were considered as reactants of the chlorination reaction. It was assumed that the hull waste and residual SNF is fed into the chlorination reaction after oxidative decladding at 700 °C, which might have cause partial/full oxidation of the hull waste and residual SNF components. Reaction temperature for the theoretical calculation was set at 330 °C. The simulation results suggested that solid phase chlorides (BaCl2, SrCl2, NdCl3, LaCl3, and RhCl3) are produced prior to formation of ZrCl4(g) and HfCl4(g). Although ZrCl4(g) is produced later than the solid products, it was expected that ZrCl4(g) can be easily separated from other chlorides as it is a gas phase at 330 °C. Therefore, it was concluded that the decladding ratio might not affect formation of ZrCl4(g) when sufficient chlorine gas was supplied. Equilibrium composition analysis suggested that highly pure ZrCl4(g) with 0.006 mol.% of HfCl4(g) might be recovered from the hull waste via the chlorination reaction method.

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Abstract  

The objective of this research is to trace the sources of stream sediments in a small watershed influenced by anthropogenic and lithogenic origins identified by the spatial distributions and temporal variations of stream sediments using geochemical interpretation of the stable and radiogenic isotopes, major components, and heavy metals data and principal component analysis. To know the effects of both present and past mining, the stream sediments were sampled at the stream tributaries and sediment coring work. The spatial distributions of heavy metals clearly showed the effects of Cu and Pb–Zn mineralization zones at the site. Anthropogenic Pb was elevated at the downstream area by the stream sediments due to an active quarry. The results of principal components analysis also represent the effects of the stream sediments origins, including anthropogenic wastes and the active quarry and lithogenic sediment. Anomalous Cu, indicating the effect of past Guryong mining, was identified at the deep core sediments of 1.80–5.05 m depth. The influence of active quarry was shown in the recently deposited sediments of <1.50 m depth, which was proved by the profiles of radioactive 210Pb and stable Pb and Sr isotopes. This study suggests that the chemical studies using radiogenic and stable isotopes and heavy metals and multivariate statistical method are useful tools to discriminate the sources of stream sediments with different origins.

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Abstract  

The removal of Cs and Re (as a surrogate for Tc) by selective precipitation from the simulated fission products which were co-dissolved with uranium during the oxidative dissolution of spent fuel in a Na2CO3–H2O2 solution was investigated in this study. The precipitations of Cs and Re were examined by introducing sodium tetraphenylborate (NaTPB) and tetraphenylohosponium chloride (TPPCl), respectively. The precipitation of Cs by NaTPB and that of Re by TPPCl each took place within 5 min, and an increase in temperature up to 50 °C and a stirring speed up to 1000 rpm hardly affected their precipitation rates. The most important factor in the precipitation with NaTPB and TPPCl was found to be a pH of the solution after precipitation. Since Mo tends to co-precipitate with Cs or Re at a lower pH, an effective precipitation with NaTPB and TPPCl was done at pH of above 9 without the co-precipitation of Mo. More than 99% of Cs and Re were precipitated when the initial concentration ratio of NaTPB to Cs was above 1 and when that of TPPCl to Re was above 1. The precipitation of Cs and Re was never affected by the concentration of Na2CO3 and H2O2, even though they were raised up to 1.5 and 1.0 M, respectively. Precipitation yields of Cs and Re in a Na2CO3–H2O2 solution were found to be dependent on the concentration ratios of [NaTBP]/[Cs] and [TPPCl]/[Re].

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Abstract  

A new static contactor was developed for solvent extraction using capillary phenomena induced among clearances formed within a highly packed fiber bundle. Feeding two immiscible phases cocurrently into the fiber bundle generated a very large liquid-liquid contact area for mass transfer within the fiber bundle without any flow turbulence or drop phenomena. In order to test the characteristics and stability of the fiber bundle contactor, continuous extraction experiments were carried out using the fiber bundle contactor with a TBP-uranyl ion-nitric acid system. The fiber bundle contactor had the same extraction performance as that of an ideal batch extractor with good reproducibility due to the sufficient liquidliquid contact area generated by the packed fiber bundle. A minimum residence time of the aqueous phase within the fiber bundle contactor was required for the extraction system to reach an extraction equilibrium state. In the TBP-uranyl ion-nitric acid system, the residence time was about 1.9 minutes. This contactor was confirmed to be effective enough to perform solvent extraction and to study the extraction kinetics because of the stable and large static liquid-liquid contact area.

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Abstract  

In order to remove U, Tc, and Np, which are positioning materials or target nuclides for transmutation, from the high-level radioactive waste, conditions of co-extraction and sequential stripping of the nuclides were studied by using 30 vol.% TBP. On the basis of the experiments performed on each element of U, Tc, and Np, a combination of co-extraction of U, Tc, Np Tc stripping Np stripping U stripping was suggested. To enhance the Np extraction yield, the electrolytic oxidation of Np(V) was required at the co-extraction step. For the stripping of Tc 5M HNO3, of Np the electrolytic reduction of Np(VI) to Np(V), and of U 0.3M sodium carbonate were used. Phase ratios (O/A or A/O) were recommended to be of 2-3, for co-extraction and for stripping.

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Abstract  

The electrochemical redox behavior of nitric acid was studied using a glassy carbon fiber column electrode system, and its reaction mechanism was suggested and confirmed in several ways. Electrochemical reactions in less than 2.0M nitric acid was not observed. However, in more than 2.0M nitric acid, the reduction of nitric acid to nitrous acid occurred and the reduction rate was slow so that the nitric acid solution had to be in contact with an electrode for a period of time long enough for an apparent reduction current of nitric acid to nitrous acid to be observed. The nitrous acid generated in more than 2.0M nitric acid was rapidly and easily reduced to nitric oxide by an autocatalytic reaction. Sulfamic acid was confirmed to be effective to destroy the nitrous acid. At least 0.05M sulfamic acid was necessary to scavenge the nitrous acid generated in 3.5M nitric acid.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
Kwang-Wook Kim
,
Kee-Chan Song
,
Eil-Hee Lee
,
In-Kyu Choi
, and
Jae-Hyung Yoo

Abstract  

The change of Np oxidation state in nitric acid and the effect of nitrous acid on the oxidation state were analyzed by spectrophotometry, solvent extraction, and electrochemical methods. The Np extraction with 30 vol.% TBP was enhanced by the adjustment of the Np oxidation state using a glassy carbon fiber column electrode system. The knowledge of electrolytic behavior of nitric acid was important because the nitrous acid affecting the Np redox reaction was generated during the adjustment of the Np oxidation state. The Np solution used in this work consisted of Np(V) and Np(VI) but no Np(IV). The ratio of Np(V) in the range of 0.5M5.5 M nitric acid was 32%19%. The electrolytic oxidation of Np(V) to Np(VI) in the solution enhanced the Np extraction efficiency about five times higher than without electrolytic oxidation. It was confirmed that the nitrous acid in a concentration of less than about 10–5 M acted as a catalyst to accelerate the chemical oxidation reaction of Np(V) to Np(VI).

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Abstract

This paper suggests a method for Subject–Action–Object (SAO) network analysis of patents for technology trends identification by using the concept of function. The proposed method solves the shortcoming of the keyword-based approach to identification of technology trends, i.e., that it cannot represent how technologies are used or for what purpose. The concept of function provides information on how a technology is used and how it interacts with other technologies; the keyword-based approach does not provide such information. The proposed method uses an SAO model and represents “key concept” instead of “key word”. We present a procedure that formulates an SAO network by using SAO models extracted from patent documents, and a method that applies actor network theory to analyze technology implications of the SAO network. To demonstrate the effectiveness of the SAO network this paper presents a case study of patents related to Polymer Electrolyte Membrane technology in Proton Exchange Membrane Fuel Cells.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
Dong-Yong Chung
,
Heui-Seung Seo
,
Jae-Won Lee
,
Han-Beom Yang
,
Eil-Hee Lee
, and
Kwang-Wook Kim

Abstract  

A feasibility and basic study to find a possibility to develop such a process for recovering U alone from spent fuel by using the methods of an oxidative leaching and a precipitation of U in high alkaline carbonate media was newly suggested with the characteristics of a highly enhanced proliferation-resistance and more environmental friendliness. This study has focused on the examination of an oxidative leaching of uranium from SIMFUEL powders contained 16 elements (U, Ce, Gd, La, Nd, Pr, Sm, Eu, Y, Mo, Pd, Ru, Zr, Ba, Sr, and Te) using a Na2CO3 solution with hydrogen peroxide. U3O8 was dissolved more rapidly than UO2 in a carbonate solution. However, in the presence of H2O2, we can find out that the leaching rates of the reduced SIMFUEL powder are faster than the oxidized SIMFUEL powder. In carbonate solutions with hydrogen peroxide, uranium oxides were dissolved in the form of uranyl peroxo-carbonato complexes. UO2(O2) x (CO3) y 2−2x−2y , where x/y has 1/2, 2/1.

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