• Nuclear Engineering and Technology
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• v.24 no.3
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• pp.297-310
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• 1992

FLECHT SEASET unblocked forced reflood tests are assessed using Apollo version of RELAP5/MOD3 5M5. The main purpose of the study is to examine the code predictability under forced reflood conditions having different initial power levels and flooding rates. Among various test matrices, the assessment calculations are performed for the test numbers 31701 31302, 31203, 31805, 34524, 31021, 34006 and 35807 These have been selected because they have similar initial conditions but different initial peak rod powers or flooding rates. In addition, various sensitivity calculations are performed for test number 31203 on the improved models of RELAP5/MOD3. Those are for the effect of Counter Current Flow Limit (CCFL) option at the outlet junction of the test section, for the effect of grid modelling on the interfacial drag calculations as well as on the heat structure calculations, and for the effect of nodalization and the time step size. The results of sensitivity studies show that the improved models of RELAP5/MOD3 enhance the code predictability. The assessment results show that the RELAP5/MOD3 has a tendency to underpredict the turn around temperature and the turn around time. But RELAP5/MOD3 silghtly overpredicts the turn around temperature for high flooding rate. The results also show that the calculated quenching by RELAP5/MOD3 is delayed with the increase of the rod power or the decrease of the flooding rate.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.4
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• pp.462-470
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• 2012

Mountain cultivated ginseng (MCG) is a type of Panax ginseng C. A. Mayer, grown in the mountains by artificial seeding. In general, it has been known that the biophysical activities of MCG is greater than that of ginseng. However, the in vivo efficacy of MCG on cancer has not been studied. In this study, we investigated the anti-carcinogenic effect of MCG and ginseng using the 7,12-dimethylbenz[a]anthracene (DMBA)-12-O-tetradecanoylphorbol- 13-acetate (TPA) two stage mouse skin carcinogenesis model. Six weeks of female ICR mice were divided into control, MCG, and ginseng diet groups and were subjected into two different experimental protocols. In the first study, each experimental diet was fed with TPA promotion for 24 weeks. The result showed that supplementation of MCG reduced tumor incidence, tumor multiplicity, and tumor size compared to those of the control and ginseng groups. In the second study, 3 groups of mice were supplied with each diet 4 weeks before DMBA tumor initiation, until the end of experiment. The result showed that tumor incidence, tumor multiplicity, and tumor size were reduced in the ginseng diet group compared to those of the control and MCG groups. TPA-induced BrdU incorporation was also significantly reduced in the ginseng diet group. Taken together, these results suggest that MCG is chemotherapeutic, whereas ginseng has a chemopreventative effect on mouse skin cancer.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.1
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• pp.73-87
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• 2018

A variety of micro meteorological variables such as air temperature, wind, solar radiation and latent heat at Gwangneung forests (conifer and broadleaved forests) and AWS (Automated Weather Station) of Pocheon urban area were used to quantify the air temperature reduction effect of forests, which is considered to be an eco-friendly solution for reducing the urban heat island intensity during summer. In June, July and August of 2016 and 2017, the average maximum air temperature differences between above and below canopy of forests, and between the forests and urban areas were $-1.9^{\circ}C$ and $-3.4^{\circ}C$ respectively, and they occurred at 17:00. However, there was no difference between conifer and broadleaved forests. The effect of air temperature reduction by the forests was positively correlated with accumulated evapotranspiration and solar radiation from 14:00 to 17:00 and showed a negative correlation with wind speed. We have developed a model to quantify the effect of air temperature reduction by forests using these variables. The nighttime air temperature reduction effect by forests was due to the generation of cold air from radiative cooling and the air temperature inversion phenomenon that occurs when the generated cold air moves down the side of mountain. The model was evaluated in Seoul by using 28 AWSs. The evaluation shows that the air temperature of each district in Seoul was negatively correlated with the area and size of the surrounding tall vegetation that drives vegetation evapotranspiration during the day. During the night, however, the size of the surrounding tall vegetation and the elevations of nearby mountains were the main influencing factors on the air temperature. Our research emphasizes the importance of the establishment and management of urban forests and the composition of wind roads from mountains for urban air temperature reduction.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2225-2229
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• 2013

Background: As data on the relation between obesity and lymph node ratio are missing in the literature, we here aimed to assess the impact of obesity on this parameter and other clinicopathological features of breast cancer cases and patient survival. Materials and Methods: Medical data of 646 patients, all referred to two centers in Tehran, Iran, were reviewed. Factors that showed significant association on univariate analysis were entered in a regression model. Kaplan-Meier and Cox-regression were employed for survival analysis. Results: Obesity was correlated with the expression of estrogen and progesterone receptor (p=0.004 and p=0.039, respectively), metastasis to axillary lymph nodes (p=0.017), higher lymph node rate (p<0.001) and larger tumor size (p<0.001). The effect of obesity was stronger in premenopausal women. There was no association between obesity and expression of human epidermal growth factor receptor. Three factors showed independent association with BMI on multivariate analysis; tumor size, estrogen receptor and lymph node ratio. Obesity was predictive of shorter disease-free survival with a hazard ratio of 3.324 (95%CI: 1.225-9.017) after controlling for the above-mentioned variables. Conclusions: The findings of this study support the idea that obese women experience more advanced disease with higher axillary lymph node ratio, and therefore higher stage at the time of diagnosis. Furthermore, obesity was associated with poorer survival independent of lymph node rate.

• Parasites, Hosts and Diseases
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• v.52 no.2
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• pp.151-162
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• 2014

The technique of stem cells or hepatocytes transplantation has recently improved in order to bridge the time before whole-organ liver transplantation. In the present study, unfractionated bone marrow stem cells (BMSCs) were harvested from the tibial and femoral marrow compartments of male mice, which were cultured in Dulbecco's modified Eagle's medium (DMEM) with and without hepatocyte growth factor (HGF), and then transplanted into Schistosoma mansoni- infected female mice on their 8th week post-infection. Mice were sacrificed monthly until the third month of bone marrow transplantation, serum was collected, and albumin concentration, ALT, AST, and alkaline phosphatase (ALP) activities were assayed. On the other hand, immunohistopathological and immunohistochemical changes of granuloma size and number, collagen content, and cells expressing OV-6 were detected for identification of liver fibrosis. BMSCs were shown to differentiate into hepatocyte-like cells. Serum ALT, AST, and ALP were markedly reduced in the group of mice treated with BMSCs than in the untreated control group. Also, granuloma showed a marked decrease in size and number as compared to the BMSCs untreated group. Collagen content showed marked decrease after the third month of treatment with BMSCs. On the other hand, the expression of OV-6 increased detecting the presence of newly formed hepatocytes after BMSCs treatment. BMSCs with or without HGF infusion significantly enhanced hepatic regeneration in S. mansoni-induced fibrotic liver model and have pathologic and immunohistopathologic therapeutic effects. Also, this new therapeutic trend could generate new hepatocytes to improve the overall liver functions.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.6
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• pp.2503-2508
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• 2013

Single-person households in the Seoul Metropolitan Area have increased sharply during recent 20-30 years. Despite of decreasing in the total population, the number of single-person household is predicted to increase continuously. However, the effect of single-person household growth on the domestic transport sector has not been studied concretely. In this study, the differences on trip generation characteristics by household size and attributes were figured out by analyzing Seoul Metropolitan Area Household Travel Behavior Survey (SMA-HTBS). Firstly, trip generation rates (trips/day/person) were produced by household attribute, household member attribute and trip attribute based on SMA-HTBS. Secondly, trip generation rate of single-person household and that of multi-person (2 or more) household were compared by significance test. It was found that trips generation characteristics of single-person household is quite different from those of multi-person household by housing type, residential type, living area, and transport mode. The result of this paper is expected to contribute developing more sophisticated trip generation model and transport policy reflecting trip generation characteristics of single-person household.

• Journal of Ocean Engineering and Technology
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• v.23 no.2
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• pp.69-73
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• 2009

The objective of this study was to obtain a better understanding of the delayed hydride cracking (DHC) of Zr-2.5Nb alloy. The DHC model has some defects: first, it cannot explain why the DHC velocity (DHCV) becomes constant regardless of an applied stress intensity factor, even though the stress gradient is affected by the applied stress intensity factor at the notch tip. Second, it cannot explain why the DHCV has a strong dependence on the method of approaching the test temperature by a cool-down or a heating-up, even under the same stress gradient, and third, it cannot predict any hydride size effect on the DHC velocity. The DHC tests were conducted on Zr-2.5Nb compact tension specimens with the test temperatures reached by a heating-up method and a cool-down method. Crack velocities were measured in hydrided specimens, which were cooled from solution-treatment temperatures at different rates by being furnace-cooled, water-quenched, and liquid nitrogen-quenched. The resulting hydride size, morphology, and distributions were examined by optical metallography. It was found that fast cooling rates, which produce very finely dispersed hydrides, result in higher crack growth rates. This different DHC behavior of the Zr-2.5Nb tube with the cooling rate after a homogenization treatment is due to the precipitation of the $\gamma$-hydrides only in the water-quenched Zr-2.5Nb tube. This experiment will provide supporting evidence that the terminal solid solubility of a dissolution (TSSD) of $\gamma$-hydrides is higher than that of $\delta$-hydrides.

• Journal of Powder Materials
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• v.18 no.1
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• pp.41-48
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• 2011

As a pore precursor, carbon black with different content of 0 to 60 vol% were added to (Ba,Sr)$TiO_3$ powder. Porous (Ba,Sr)$TiO_3$ ceramics were prepared by pressureless sintering at $1350^{\circ}C$ for 1h under air. Effects of carbon black content on the microstructure and PTCR characteristics of porous (Ba,Sr)$TiO_3$ ceramics were investigated. The porosity of porous (Ba,Sr)$TiO_3$ ceramics increased from 6.97% to 18.22% and the grain size slightly decreased from $7.51\;{\mu}m$ to $5.96\;{\mu}m$ with increasing carbon black contents. PTCR jump of the (Ba,Sr)$TiO_3$ ceramics prepared by adding carbon black was more than $10^5$, and slightly increased with increasing carbon black. The PTCR jump in the (Ba,Sr)$TiO_3$ ceramics prepared by adding 40 vol% carbon black showed an excellent value of $9.68{\times}10^5$, which was above two times higher than that in (Ba,Sr)$TiO_3$ ceramics. These results correspond with Heywang model for the explanation of PTCR effect in (Ba,Sr)$TiO_3$ ceramics. It was considered that carbon black is an effective additive for preparing porous $BaTiO_3$ based ceramics. It is believed that newly prepared (Ba,Sr)$TiO_3$ cermics can be used for PTC thermistor.

• Journal of Korean Library and Information Science Society
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• v.7
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• pp.177-206
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• 1980

Public library legislation is the essential means of providing for all the citizen in modern society with a standard public library service. We can trace the origin of that back to the Public Libraries Act 1850 in England. This paper is reviewing all the measures concerning public libraries of England since then in order to find out some guidelines for revision of the Korean Library Law enacted in 1963. Although Public Libraries Act 1850 was an output of a series of social reform movement in the 19th century, it established first the provision of public library service su n.0, pported by public funds. However the Act had several restrictions hindering public library service from making progress. These are: 1. Adoptive legislation in nature 2. Limitation of the size of population and rate income 3. Small library authorities 4. Procedure for adoption by public meeting 5. Restrictions on the ways in which rate income might be spent 6. No governmental organization to direct or control for a standardized public library service 7. No cooperative schemes among libraries. Subsequent development was directed largely to removal of those limitations. The present Public Libraries Act 1964 as a model of public library legislation was enacted on the basis of such reports as Kenyon, McColvin, Roberts, and Bourdillon. All but the problem of small library authorities were removed with this new Act. The final object could be achieved by the Local Government Act 1974 which reorganized existing 383 small authorities into new 115 ones the average population of which was 280, 000. Now, McColvin's dream of 30 years could be fulfilled in the late 70's. He argued that the minimum size of population of a viable authority should be 300, 000. Although the effect of the 1964 Act on the development of public library services in England was great, there must be some considerations as to the provisions of public library objective, government funding for library services, free use of library materials to all regardless of residence, and placement of library committee within the authority.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.4
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• pp.333-338
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• 2008

The coastal zone is a delicate and dynamic area in which the majority of a water kinetic energy is dissipated. These processes are subsequent to the transport of the beach materials. In comparison to emerged breakwaters, submerged structures permit the passage of some wave energy and in turn allow for circulation along the shoreline zone. This research aims to examine the beach erosion prevention capability of submerged structure by laboratory model. The flow characteristics behind a submerged obstacle with bottom gap were experimentally investigated at Re = $1.2{\times}10^4$ using the two-frame PIV(CACTUS 2000) system. Streamline curvature field behind the obstacle has been obtained by using the data of time-averaged mean velocity information. And the large eddy structure in the separated shear layer seems to have signification influence on the development of the separated shear layer. As bottom gap size increases, the recirculation occurring behind the obstacle moves toward downstream and its strength is weakened.