• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.15 no.1
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• pp.35-44
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• 2017

A gamma-ray peak of $^{226}Ra$ (186.2 keV) overlaps with one of $^{235}U$ (185.7 keV) in a gamma-ray spectrometry system. Though reference peaks of $^{235}U$ can be used to correct the peak interference of $^{235}U$ in the analysis of $^{226}Ra$, this requires a complicated calculation process and a high limit of quantitation. On the other hand, evaluating $^{226}Ra$ using the correction constant in the overlapped peak can make a rapid measurement of $^{226}Ra$ without the complicated calculation process as well as overcome the disadvantage in the indirect measurement of $^{214}Bi$, which means the confinement of $^{222}Rn$ gas in a sample container and a time period to recover the secular equilibrium. About 93 samples with 6 species for raw-materials and by-products were prepared to evaluate the activity of $^{226}Ra$ using the correction constant. The results were compared with the activity of $^{214}Bi$, which means the indirect measurement of $^{226}Ra$, to validate the method of the direct measurement of $^{226}Ra$ using the correction constant. The difference between the direct and indirect measurement of $^{226}Ra$ was generally below about ${\pm}20%$. However, in the case of the phospho gypsum, a large error of about 50% was found in the comparison results, which indicates the disequilibrium between $^{238}U$ and $^{226}Ra$ in the materials. Application results of the contribution ratio of $^{226}Ra$ were below about ${\pm}10%$. The direct measurement of $^{226}Ra$ using the correction constant can be an effective method for its rapid measurement of raw materials and by-products because the activity of $^{226}Ra$ can be produced with a simple calculation without the consideration of the integrity of a sample container and the time period to recover the secular equilibrium.

• The Journal of the Petrological Society of Korea
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• v.23 no.3
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• pp.167-185
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• 2014

SHRIMP zircon U-Pb ages and major element and Sr-Nd isotopic compositions were determined for drill cores (374-3390 m in depth) recovered from three boreholes in the Pohonag basin, southeastern Korea. Shallow-seated volcanic rocks and underlain plutonic rocks were geochemically classified as rhyolite and gabbro-granite, respectively. They showed high-K calc-alkaline trends on the $K_2O-SiO_2$ and AFM diagrams. Zircons from volcanic rocks of borehole PB-1 yielded concordia ages of $66.84{\pm}0.66Ma$ (n=12, MSWD=0.02) and $66.52{\pm}0.55Ma$ (n=12, MSWD=0.46). Zircons from volcanic rocks of borehole PB-2 gave a concordia age of $71.34{\pm}0.85Ma$ (n=11, MSWD=0.79) and a weighted mean $^{206}Pb/^{238}U$ ages of $49.40{\pm}0.37Ma$ (n=11, MSWD=1.9). On the other hand, zircons from plutonic rocks of borehole PB-3 yielded weighted mean $^{206}Pb/^{238}U$ ages of $262.4{\pm}3.6Ma$ (n=21, MSWD=4.5), $252.4{\pm}3.6Ma$ (n=8, MSWD=1.9) and $261.8{\pm}1.5Ma$ (n=31, MSWD=1.3). Detrital zircons from the sedimentary strata overlain the volcanic rocks showed a wide age span from Neoproterozoic to Cenozoic, with the youngest population corresponding to $21.89{\pm}1.1Ma$ (n=15, MSWD=0.04) and $21.68{\pm}1.2Ma$ (n=10, MSWD=19). These dating results indicate that the basement of the Pohang basin is composed of Late Permian plutonic rocks and overlain Late Cretaceous to Eocene volcanic sequences. Miocene sediments were deposited in the uppermost part of the basin, possibly associated with the opening of the East Sea. The Sr-Nd isotopic compositions of the Permian plutonic rocks were comparable with those reported from Permian-Triassic granitoids in the Yeongdeok area, northern Gyeongsang basin. They may have been recycled into parts of the Cretaceous-Paleogene magmatic rocks within the Gyeongsang basin.

• Journal of Korean Academy of Nursing
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• v.43 no.1
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• pp.69-80
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• 2013

Purpose: The purpose of the study was to investigate the effects of an integrated self-management program on self-management, glycemic control, and maternal identity in women with gestational diabetes mellitus (GDM). Methods: A non-equivalent control group non-synchronized quasi-experimental design was used. A total of 55 women with GDM were recruited from Cheil General Hospital, Seoul, Korea and were assigned to an experimental (n=28) or control group (n=27). The participants were 24-30 weeks pregnant women who had been diagnosed with GDM as of July 30, 2010. The program was conducted as a 1 hour small group meeting 3 out of 5 times and by telephone-counseling 2 out of 5 times. The integrated self-management program was verified by an expert panel. Results: Although there was no significant reduction in HbA1c (U= -1.17, p=.238), there were statistically significant increases in self-management (U= -3.80, p<.001) and maternal identity (U= -4.48, p<.001), and decreased 2-h postprandial glucose levels (U= -2.43, p<.015) in the experimental group compared to the control group. Conclusion: These findings suggest that an integrated self-management program for women with GDM improves self-management, maternal identity, and glycemic control. Further studies are needed to identify the effects of an integrated self-management program on pregnancy and neonatal outcomes.

• Korean Journal of Food Science and Technology
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• v.7 no.4
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• pp.238-242
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• 1975

The effects of various antimicrobial agents on the production of organic acid and saccharifying amylase by Aspergillus usamii shirousamii $U_2$ were studied and the results are as follows. 1) The production of organic acid and saccharifying amylase was stimulated by using optimum amounts of nitrofurazone and $AF_2$ among several antimicrobial agents. 2) Wheat flour medium containing 50% volumes of 10 ppm $AF_2$ solution gave the maximum yield of organic acid. 3) Wheat bran medium containing 100% volumes of $100{\sim}500ppm$ nitrofurazone solution gave the maximum yield of saccharifying amylase.

• Nuclear Engineering and Technology
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• v.42 no.1
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• pp.79-88
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• 2010

Spent $UO_2$ nuclear fuel discharged from a nuclear power plant (NPP) contains fission products, U, Pu, and other actinides. Due to neutron capture by $^{238}U$ in the rim region and a temperature gradient between the center and the rim of a fuel pellet, a considerable increase in the concentration of fission products, Pu, and other actinides are expected in the pellet periphery of high burnup fuel. The characterization of the radial profiles of the various isotopic concentrations is our main concern. For an analysis, spent nuclear fuels originating from the Yeonggwang-2 pressurized water reactor (PWR) were chosen as the test specimens. In this work, the distributions of some actinide isotopes were measured from center to rim of the spent fuel specimens by a radiation shielded laser ablation inductively coupled plasma mass spectrometer (LA-ICP-MS) system. Sampling was performed along the diameter of the specimen by reducing the sampling intervals from 500 ${\mu}m$ in the center to 100 ${\mu}m$ in the pellet periphery region. It was observed that the isotopic concentration ratios for minor actinides in the center of the specimen remain almost constant and increase near the pellet periphery due to the rim effect apart from the $^{236}U$ to $^{235}U$ ratio, which remains approximately constant. In addition, the distributions of local burnup were derived from the measured isotope ratios by applying the relationship between burnup and isotopic ratio for plutonium and minor actinides calculated by the ORIGEN2 code.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.3
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• pp.236-238
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• 2004

This is the first report on the antitumor and immunostimulating activities of Ulva lactuca. Using the WSM (water-soluble fraction of a methanol extract from Ulva lactuca), a concentration of 140 g/mL was found to inhibit 50% of the human leukemia cell line U937 in growth, while splenocyte growth was stimulated up to a concentration of 100$\mu\textrm{g}$/mL. In addition, NO production by a macrophage cell line (RAW 264.7) and alkaline phosphatase activity in mouse splenocytes were both stimulated with 10$\mu\textrm{g}$/mL of WSM. Dose-dependent patterns were observed on all three cell-lines. Accordingly, the current results indicate that VUlva lactuca may be useful as a natural antitumor and immunostimulating agent.

• Phonetics and Speech Sciences
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• v.2 no.4
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• pp.229-238
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• 2010

This study investigates the differences in acoustic parameters in vowel space across hearing loss, gender and vowels. The parameters include F1, F2, Euclidean Distance between vowels, and vowel triangular area comprised of /i/, /a/ and /u/. For this study, 20 hearing-impaired and normal hearing adults as a control group were asked to read 7 Korean vowels (/a, $\wedge$, o, u, w, i, $\varepsilon$/). Subjects' readings were recorded by NasalView and analyzed by Praat. Results showed that F1 were significantly higher in the hearing impaired group than in the normal hearing group, higher in the female group than in male group, and higher in low vowels than in high vowels. And the means of F2 was significantly higher in the hearing impaired group than in normal hearing group, higher in high vowels than in low vowels, and there was no difference between male and female group. Secondly, Euclidean distance between vowels was significantly shorter in the hearing-impaired group than in the normal group. Finally, acoustic vowel space area was significantly smaller in the hearing-impaired group than in the normal hearing group. The hearing-impaired group showed that front vowels tended to be backed and back vowels to be fronted.

• Journal of Embryo Transfer
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• v.17 no.3
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• pp.235-238
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• 2002

The present study was undertaken to find out possibilities for superovulation and recovery of freezable/transferable embryo from repeat breeding crossbred cows. For this study a total of 10 Holstein crossbred cows having history of failure of conception even after more than 4~5inseminations were taken and superovulated using Folltropin-V at 100 to 140% dose schedule. The results indicated that out of 10 donors, 8 responded to superovulatory treatment and yielding a total of 94 embryos, out of which 45 were of transferable/freezable quality. The mean ovulations and mean transferable embryos were 11.5$\pm$2.91 and 4.5$\pm$1.66, respectively. These observations suggests that the repeat breeding cows having conception failure after several artificial inseminations can be used as donors for production of embryos and calves through embryo transfer technology.

• Journal of fish pathology
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• v.15 no.3
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• pp.117-119
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• 2002

A kind of leeches, Trachelobdella sp was detected on the inside surface of the opercle of wild crucian carp, Carassius cuvieri (21.5 cm in length and 238.5 g in weight) at a reservoir for agriculture in ChungNam Province of Korea in March, 2002. Two or three round transparent spots on the opercle could be easily detected. The fish also showed severe anemia and dorsally darking in the gill lamellae. The parasites was identified as Trachelobdella sp. on the basis of morphological characteristics such as suckers, body segmentation and lateral diverticula. As the parasites fed on host blood after attaching on the inside surface of the opercle by means of the posterior sucker, they caused severe anemia and petechial haemorrhge on the gill of infested fish. Heavy infestation of the parasite resulted in dath of fish because of large amount of blood loss.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.02a
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• pp.182-190
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• 2004

An unique extraction chromatographic column (TOA: Tri-n-octylamine on Teflon powder) with a two-stage sample loading was prepared to separate Np and Pu from the environmental matrix. Np and Pu were efficiently retained in 4 M $HNO_3$ medium on the column and easily eluted with 0.02 M oxalic acid in 0.16 M HNO$_3$at $95^{\circ}C$. The separated solutions were free from most of the matrix elements and were aspirated into the ICP-MS directly. The decontamination factor for 238U is more than 104. The instrumental detection limit for 237Np was 0.46 pg mL-l ($1.2{\times}10_{-5}$Bq mL-l), and for 239Pu was 0.48 pg mL-l ($1.1{\times}10_{-3}$ Bq mL-l). The feasibility for the determination of both elements was proved by analysing IAEA-135 reference samples, the measured values agreed with the recommended reference value.