• Journal of radiological science and technology
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• v.16 no.1
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• pp.41-55
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• 1993

Recently, various screen film system have been introduced in diagnostic radiology. There are two kinds of screen film system : blue emitting $CaWO_4$ screen has been largely used in these days. However, it tends to be changed to use green emitting $Gd_2O_2S$ : Tb screen. In this study, photographic characteristics of $CaWO_4$ and $Gd_2O_2S$ : Tb screen were investigated with luminescence, spectroscopy. The morphology of $CaWO_4$ and $Gd_2O_2S$ : Tb were also observed by using scanning electron microscope. The result obtained were as follows : 1. There was small difference in the thickness of phosphor layers for the front and back screen of blue emitting system, but little difference in those of green emitting system. 2. There was no difference in the size of phosphor particles between the front and back screen for each screen. However, the particle size was different for the various kinds of screens. 3. The shape of phosphor particle was round with many faces for all the screens. 4. In the exposure of X-ray with the same intensity, luminescent intensity of a green emitting system was $6{\sim}7$ times larger than that of a blue emitting system. 5. The thickness of phosphor layers does not affect on the sensitivity of the screens exposed by X-ray.

• Journal of the Korean Ceramic Society
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• v.51 no.4
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• pp.260-264
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• 2014

We developed a novel double dopant bismuth oxide system with Tb and W. When Tb was doped as a single dopant, a Tb dopant concentration more than 20 mol% was required to stabilize bismuth oxides with a high conductivity cubic structure. High temperature XRD analysis of 25 mol% Tb-doped bismuth oxide (25TSB) confirmed that the cubic structure of 25TSB was retained from room temperature to $700^{\circ}C$ with increase in the lattice parameter. On the other hand, we achieved the stabilization of high temperature cubic phase with a total dopant concentration as low as ~12 mol% with 8 mol% Tb and 4 mol% W double dopants (8T4WSB). Moreover, the measured ionic conductivity of 10T5WSB was much higher than 25TSB, thus demonstrating the feasibility of the double dopant strategy to develop stabilized bismuth oxide systems with higher oxygen ion conductivity for the application of SOFC electrolytes at reduced temperature. In addition, we investigated the long-term stability of TSB and TWSB electrolytes.

• Bulletin of the Korean Chemical Society
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• v.30 no.3
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• pp.675-678
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• 2009

$Fe_2O_3,\;Ag_2O,\;CaWO_4$ and $Gd_2O_2S$:Tb loaded on titanium dioxide photocatalysts (P25, Degussa) were prepared by a calcination. Their composite films containing water-born polyurethane used as a material for immobilization were obtained by spray coating technique. The photocatalytic activity of the titanium dioxide films was characterized by decrease of UV-vis absorption spectra for methylene blue and gas chromatography for photocatalytic decomposition of formaldehyde diluted in water. It was shown that the $Gd_2O_2S$:Tb modified titanium dioxide films had good photocatalytic properties and followed the first-order kinetic model with regard to photocatalytic decoloration of methylene blue. Especially in formaldehyde photodegradation experiment, decrease rate of concentration of the titanium dioxide films with $Gd_2O_2S$:Tb modifying was about 35% larger than that of the unloaded titanium dioxide film.

• Korean Journal of Materials Research
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• v.17 no.6
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• pp.298-302
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• 2007

The electrical properties and its stability of Zn-Pr-Co-Cr-Tb-based varistors were investigated for different sintering temperatures. As the sintering temperatures increased, the varistor voltage decreased in the range of $705.2{\sim}299.1$ V/mm, the nonlinear coefficient decreased in the range of $42.4{\sim}31.7$, and the leakage current was in the range of $1.0{\sim}1.7\;{\mu}A$. The stability of electrical characteristics increased with the increase of sintering temperature. The varistors sintered at $1350^{\circ}C$ marked the high electrical stability, with $%\Delta$ $V_{1mA}=+0.1%,\;%\Delta{\alpha}=+3.2%$, and $%{\Delta}I_L=+117.6%$ for DC accelerated aging stress state of $0.95V_{1mA}/150^{\circ}C/24\;h$.

• Physical Therapy Rehabilitation Science
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• v.6 no.3
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• pp.152-157
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• 2017

Objective: The aim of this study was to determine the intra-rater and inter-rater reliability of the dual rehabilitative ultrasound imaging (D-RUSI) when simultaneously measuring muscle thickness changes at rest and during co-contraction of the biceps brachii (BB) and triceps brachii (TB). Design: Cross-sectional study. Methods: This study included 36 healthy participants (23 men, 13 women). The participants sat on a chair in a comfortable position with a cushion placed under their elbow to maintain a 90-degree elbow flexion angle. The muscle thickness of the biceps brachii and triceps brachii was measured twice using the D-RUSI by two examiners during resting and co-contraction states. One week later, the same procedure was performed once again. Results: The intra-class correlation coefficients (ICCs) for intra-rater reliability ranged from 0.887 to 0.989 and the confidence interval was within an acceptable range of 0.778 to 0.994. The standard error of measurement (SEM) values ranged from 0.303 to 0.866 and the minimal detectable change (MDC) values ranged from 0.84 to 2.40. The ICCs for inter-rater reliability ranged from 0.758 to 0.925. The SEM values ranged from 0.702 to 1.486 and the MDC values ranged from 1.95 to 4.12. Conclusions: The use of the D-RUSI of the BB muscle had a very good intra-rater reliability and very good inter-rater reliability at the resting state, and a, good inter-rater reliability at the co-activation state. ICC values showed very good intra-reliability and inter-reliability for the TB muscle. the D-RUSI is a useful tool for simultaneously measuring the thickness of two muscles when the BB is an agonist and the TB is an antagonist during co-activation of the upper arm.

• Proceedings of the Korean Magnestics Society Conference
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• 1998.05a
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• pp.118-119
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• 1998

• Proceedings of the Materials Research Society of Korea Conference
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• 1992.05b
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• pp.128-128
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• 1992

• Proceedings of the Korean Magnestics Society Conference
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• 2011.06a
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• pp.4-4
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• 2011

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.1
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• pp.101-106
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• 2004

This study was conducted to examine the effect of bluefin tuna bone on the bone metabolism of the rats. Weaned 6-week old male rats were fed low-calcium diets for 2 weeks after the adjustment period. Rats were divided into 6 groups and were fed experimental diets for six weeks. Experimental groups were \circled1 Normal calcium: CC (0.5% CaCO$_3$; control) \circled2 TB (bluefin tuna bone powder) \circled3 CT (citrated bluefin tuna bone powder) \circled4 BB (bovine bone powder) \circled5 CL (calcium lactate) \circled6 Low calcium LC (0.15% CaCO$_3$). Low-calcium diet group (LC) showed the lowest calcium retention. There was no differences in calcium excretion in stool and calcium absorption among various calcium sources. Serum calcitonin levels were high in TB, CT and BB group compared to those in CC, CL LC group. Parathyroid hormone and osteocalcin levels showed no differences among experimental groups. Deoxypyridinoline (DPD) levels were significantly higher in LC group than in other groups. Wet weight of the femur were significantly high in TB and CT group, and dry weight of femur showed no differences among normal calcium groups. Bone density of femur in LC group was significantly lower than those of normal calcium feeding group, and TB group showed highest bone density among experimental groups. There was no differences in bone metabolism among various calcium sources. Therefore, it is pointed out that the amount of calcium intake is very important because there was significant differences between normal calcium diet and low calcium diet. According to the results of femur weight, ash, calcium and bone density, it is suggested that bluefin tuna bone have alternative effects to bovine bone powder on the maintenance of bone health.

• Proceedings of the Korean Magnestics Society Conference
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• 1998.05a
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• pp.82-83
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• 1998