• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.12 no.1
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• pp.7-17
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• 2014

Molten salt electrorefining process achieves uranium deposits at cathode using an electrochemical processing of spent nuclear fuel. In order to recover pure uranium from cathode deposit containing about 30wt% salt, the adhered salt should be removed by cathode process (CP). The CP has been regarded as one of the bottle-neck of the pyroprocess as the large amount of uranium is treated in this step and the operation parameters are crucial to determine the final purity of the product. Currently, related research activities are mainly based on experiments consequently it is hard to observe processing variables such as temperature, pressure and salt gas behavior during the operation of the cathode process. Hence, in this study operation procedure of cathode process is numerically described by using appropriate mathematical model. The key parameters of this research are the amount of evaporation at the distillation part, diffusion coefficient of gas phase salt in cathode processor and phase change rate at condensation part. Each of these conditions were composed by Hertz-Langmuir equation, Chapman-Enskog theory, and interphase mass flow application in ANSYS-CFX. And physical properties of salt were taken from the data base in HSC Chemistry. In this study, calculation results on the salt gas behavior and optimal operating condition are discussed. The numerical analysis results could be used to closely understand the physical phenomenon during CP and for further scale up to commercial level.

• The Journal of Korean Academy of Prosthodontics
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• v.19 no.1
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• pp.39-45
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• 1981

Distal-extension removable partial dentures have long been implicated in the increase in mobility and the destruction of the supporting structures of the primary abutment teeth. Various clasping systems have traditionally been used to retain distal extension removable partial dentures, and other designs have been proposed to minimize torquing forces on the abutment teeth. Most recent studies investigating the effects of removable partial dentures on abutment teeth have been performed in it laboratory setting. Results obtained from in vitro research have given dentists insight into removable partial denture design, but laboratory test model cannot be constructed that simulates actual functional or parafunctiona1 movements and forces. The purpose of this study was to clinically evaluate the degree of tooth mobility produced by two clasping systems (suprabulge type and infrabulge type) used for distal extension removable partial dentures. Akers clasp and R.P.I. system were selected for the evaluation, and four patients required a distal extension removable partial denture on the mandibular arch were selected for participation in the study. Two partial dentures were constructed in the same condition expect the design of clasp. All abutments in the study were mandibular first or second premolars. Measurements of mobility were made with a research tool designed by $M\"{u}hlemann$. This instrument, periodontometer, measures tooth mobility in the mouth by means of a dial gauge accurated to 0.01mm when the tooth is stressed with a force meter. Lingual and buccal deflection of abutment tooth was measured using buccal and lingual pressure. The amount of force applied was 500gm. Tooth mobility tests were made at four key stages; 1. Before insertion of the first removable partial denture, baseline mobility was establsihed. 2. After wearing of the first prosthesis, measurement was made at weekly intervals for 4 weeks. 3. The removable partial denture was then taken from the patient, and tooth mobility was measured again at weekly intervals until the patient's established baseline mobility had returned. 4. The second prosthesis of different clasp design was worn for a month and evaluated in the same manner as the first. The sequence of placement of clasping system was alternated between patients. The following results were obtained from this study; 1. The mobility of abutment tooth increased during the initial stage of wear and returned to baseline mobility after removal of removable partial dentures. 2. The mobility of abutment tooth showed no difference between Akers clasp and I-bar clasp during the 4-week test period. 3. All teeth tested showed greater mobility toward the buccal than the lingual direction.

• Genomics & Informatics
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• v.6 no.3
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• pp.99-109
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• 2008

Protein phosphorylation at tyrosine residues is a key regulatory event that modulates insulin signal transduction. We studied the PTPN1 gene with regard to susceptibility to Korean type 2 diabetes mellitus (T2DM) and its related quantitative traits. A total of seven SNPs [g.36171G>A (rs941798), g.58166G>A (rs3787343), g.58208A>G (rs2909270), g.64840C>T (rs754118), g.69560C>G (rs6020612), g.69866G>A (rs718050), and g.69934T>G (rs3787343)] were selected based on frequency (>0.05), linkage disequilibrium (LD) status, and haplotype tagging status. We studied the seven SNPs in 483 unrelated patients with type 2 diabetes (age: $64{\pm}2.8$ years, onset age: $56{\pm}8.1$ years; 206 men, 277 women) and 1138 nondiabetic control subjects (age: $64{\pm}2.9$; 516 men, 622 women). The SNP rs941798 had protective effects against T2DM with an odds ratio of 0.726 (C.I. $0.541{\sim}0.975$) and p-value=0.034, but none of the remaining six SNPs was associated with T2DM. Also, rs941798 was associated with blood pressure, HDL cholesterol, insulin sensitivity. rs941798 also has been associated with T2DM in previous reports of Caucasian-American and Hispanic-American populations. This is the first report that shows an association between PTPN1 and T2DM in the Korean as well as Asian population.

• Journal of East-West Nursing Research
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• v.5 no.1
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• pp.102-113
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• 2000

The study attempts to analyze the trends of study related with oriental nursing. This article reviewed 81 researches on oriental nursing from 1985 to July 2000, by examining them according to the articles' characteristics, sources by publication period, research design, nursing intervention effect of experimental study and concept, and content of literature review. The findings of the analysis can be summarized as follows; 1. The number of studies related with oriental nursing has progressively increased by year from 1985, and that of articles was the highest during the period between 1995 to 1999. Since the 1990s, the number of articles including thesis and dissertation increased, and a third of subject articles were thesis among them. 2. The majority of research design were survey and correlational studies, and most of them were published in the 1990s. Literature review articles also occupied a certain portion, and most of them were published after 1995. In addition, the research design of dissertation revealed in various types. 3. Nursing intervention used in the experimental study was Dan Jeon Breathing, San-Yin-Jiao (SP-6) Pressure, Percutanous Electrical Nerve Stimulation, Guided Imagery, Diet for Sasang Constitution, Yoga Exercise, Qigong Exercise, Meridian Massage, Bed Exercise Program, Health Contract and Structured Rehabilitation Education. Among the study subjects, patients with chronic illness were at the highest rate, and the most nursing intervention effects presented physiological effect, activities of daily living and relieving pain. In most studies, the affirmative effect proved. 4. The key concept of literature review articles is energy, oriental nursing, health promotion, oriental medicine management of illness and etc. Being important concepts to understand oriental nursing, they confirm similar perspective of oriental medicine and nursing and show simultaneously the importance of nursing considered into the cultural perspective. The summary of the above results shows a tendency that the thesis and dissertation have been relatively considered with various research designs, while the others have focused on literature review. Especially, experimental study proved affirmative effect through various experimental treatment of nursing intervention related with oriental medicine. Besides in the literature review, inquiry of theories and practical perspective, which is necessary for the establishment of oriental nursing, was introduced. However, for the establishment of oriental nursing, more studies are to be required along with development of nursing intervention related with health promotion.

• Journal of the Korean Geosynthetics Society
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• v.13 no.4
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• pp.33-43
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• 2014

Recently, the case to construct the structure on the soft clayey ground has increased and in order to the reduction of the cost of construction and maintenance on the social infrastructure facilities we have been trying to improve the soft clayey ground using the existing methods such as the pre-loading method and the vertical drain method. Like this, when various ground improvement methods are applied on the soft clayey ground, a long-term consolidation settlement will be key issue due to low permeability coefficient of cohesive soil. According to existing research results that relate to the consolidation settlement, the loading periods for existing the standard consolidation test (Oedometer test) to obtain the consolidation parameters are needed for minimum ten days or more. Therefore, in this study, the standard consolidation test (24 hours step-loading) and constant strain rate consolidation test changed by strain rate was performed using the remolded marine clay on Gwangyang bay composed of a soft clayey ground of the south-west coast. From the laboratory test results, the characteristics of compression, strain-effective stress relations by constant strain rate and the variation characteristic of the pore water pressure by different of loading speed and the relation between consolidation parameters and constant strain rate are compared and analyzed.

• Korean Journal of Social Welfare Studies
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• no.39
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• pp.167-187
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• 2008

This study explores the trends of social security expenditures after financial crisis in welfare states. For the purpose, this study analyzes changes in social expenditures during 1980~2003 in 22 OECD countries. The results show that average total social security expenditure(as a percentage of GDP) among the 22 countries increased from 18.0% in 1980 to 22.3% in 2003. Compared to sharp increases during the great expansion period of the welfare state before 1980s, the increase in social expenditures after 1980s is substantially weakened. The slowdown in the increases of social expenditures is remarkable in the social democratic welfare states where social expenditures have already reached a high level. On the other hand, social expenditures are considerably increased in the lagged welfare states such as South European countries and Japan. As a result, the cross-national difference in social expenditures has continuously decreased. These findings suggest that financial crisis is a key factor of welfare-state reorganization. Countries where social expenditures are in high level need more reforms under the pressure of financial deficits. Since 1980s, they have tried various reforms especially in pensions and unemployment benefits. Facing new and increasing demands for social security as well as financial limitations, the welfare state needs major reforms in the social security system to increase effectiveness/efficiency of existing programs and to iron out priorities among programs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.7-17
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• 2019

With increasing demand for large offshore infrastructures, suction cofferdams have been large, and the lid stiffener arrangement for a suction cofferdam has become a key element in cofferdam design to constrain the flexural deformation effectively. This study analyzed the changes in the structural behavior of a lid for a suction cofferdam due to lid stiffeners to provide insights into effective stiffener arrangements. By investigating conventional suction anchors, several stiffener patterns of a lid for a polygonal suction cofferdam were determined and analyzed. The structural performance of the stiffened lids was estimated by comparing the stress and deformation, and the reaction distributions on the edge of lid were investigated to analyze the effects of the stiffener arrangement on the lid-wall interface. Finite element analysis showed that radial stiffeners contribute dominantly to decreasing the stress and vertical deflection of the lids, but the stiffeners cause an increase in shear forces between the lid and wall; the forces are concentrated on the lid near the areas reinforced with radial stiffeners, which is negative to lid-wall connection design. On the other hand, inner and outer circumferential stiffeners show little reinforcement effects in themselves, while they can help reduce the stress and deformation when arranged with partial radial stiffeners simultaneously.

• Korean Chemical Engineering Research
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• v.57 no.3
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• pp.378-386
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• 2019

In the present paper we report the calculation results of operation energy consumption for dissolved ions concentration technologies using vacuum evaporation (VE) and hydrate formation. Calculations were conducted assuming the tenfold concentration of saline water (0.35 wt% NaCl solution) of 1 mol/s at room temperature and atmospheric pressure employing vacuum evaporation at $69^{\circ}C$ and 30 kPa and hydrate-based concentration using $CH_4$, $CO_2$ and $SF_6$ as guest molecules. Operation energy consumption of VE-based concentration resulted in 47 kJ/mol, whereas those of hydrate-based concentration were 43, 32, and 28 kJ/mol for $CH_4$, $CO_2$ and $SF_6$ hydrates, respectively. We observe that hydrate-based concentration can a competitive option for dissolved ions recovery from energy consumption standpoint. However, the selection of guest gas is very critical, since it accordingly determines the hydration number, the hydrate formation energy, gas compression energy, etc. The selection of guest gas, separation of concentrated brine and water phases, and the enhancement of hydrate formation rate are the key factors for the commercialization of hydrated-based technology for concentrating dissolved ions.

• Journal of the Korean Society of Earth Science Education
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• v.14 no.1
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• pp.48-58
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• 2021

The purpose of this study is to analyze the contents related to the strata in the elementary science textbooks and to investigate the strata concepts of preservice elementary teachers. As a result of the study, most of the strata knowledge in elementary textbook has an explicit sentence structure, such as A is B. it is limited to being used as a subject of discussion and debate among students in science classes. Formal knowledge, although its meaning is clear, is disadvantageous as a material for core competency education. Regarding strata concepts, 70% of preservice elementary teachers thoughts that heat and pressure were the only key factors in turning sediments into hard rocks. Regarding whether information about the natural information in the geological period can be obtained through the strata, 20% thought that information on the natural environment could be obtained only through fossils and not from the strata. Even 80% of preservice elementary school teachers who thought that informations on the past natural environment could be obtained from the stratum showed a lot of scientific misconceptions in the information contents. In conclusion, in order to increase the effect of core competency education through elementary science education, it is necessary to review the form and contents of strata knowledge presented in elementary science textbooks.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.386-391
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• 2021

Turbocharging is becoming a key technology for both diesel and gasoline engines. Regarding gasoline engines, turbocharging can help reduce carbon dioxide (CO2) emissions when used in conjunction with other technologies. This paper presents measurements of the turbine efficiency of pulsating flow in a twin-scroll turbocharger for gasoline engines. A cold gas test bench with a pulse generator was manufactured. The turbine efficiencies were calculated using the measured data of the instantaneous pressure and temperature of the inlet and exit of the turbine. The measurements were carried out at turbine speeds from 60,000 to 100,000 rpm under a pulsating flow of 25.0 Hz and 33.0 Hz. The turbine efficiencies ranged from 0.517 to 0.544. At the pulse frequency, 33.3 Hz, the variations in efficiency were 7.7% and 2.6% at turbine speeds of 60,000 rpm and 100,000 rpm, respectively. The turbine efficiency of the pulsating flow compared to those of steady flow was 7.0% and 3.0% lower at a turbine speed of 60,000 rpm and 100,000 rpm, respectively. The pulsating flow deteriorated the turbine efficiency, but the effects of pulsating flow decreased with increasing turbine speed.