• Nuclear Engineering and Technology
• /
• v.56 no.10
• /
• pp.4307-4326
• /
• 2024

This study investigates Equivalent Spherical Diameter (ESD) estimation at high inlet velocity pool scrubbing conditions using the Interfacial Area Transport Equation (IATE) diameter model including bubble-induced turbulence and interphase modeling. The compatibility of area-averaged Sauter Mean Diameter (SMD), areaaveraged Local Equivalent Diameter (LED) and void-weighted area-averaged LED approaches to estimate the ESD are explored and the proposed model is validated against available experimental data. The study reveals that the prevalent constant ESD assumption in pool scrubbing codes is not universal by showcasing a decreasing trend along the column due to intensive bubble breakup. The area-averaged LED approach fails to capture this trend, while the area-averaged SMD and void-weighted area-averaged LED approaches provide accurate estimations aligned with experimental data. Turbulence parameters, interfacial forces, and diameter modeling are identified as crucial for accurate predictions of flow and geometrical variables by setting up the OpenFOAM framework. A sensitivity analysis indicates that the inlet velocity has an acceptable effect on the ESD along the column. The ESD increases near the exit and decreases in the swarm region by increasing the inlet velocities. Turbulent intensity reduces ESD across all column sections while changes in aspect ratio minimally impact ESD. The study shows promise in developing correlations that take into account the spatial variation of ESD in pool scrubbing conditions.

• Journal of Korean Society of Forest Science
• /
• v.102 no.1
• /
• pp.107-112
• /
• 2013

The purpose of the study is to give ROI information about management status and investment returns to someone who will newly cultivate Rhus verniciflura and expand area of Rhus verniciflura cultivation. In this study, IRR (Internal Rate of Returns), B/C Ratio and NPV are applied for ROI analysis. We basically surveyed thirty household among Rhus verniciflura cultivation farmhouses in chief producing districts Won-ju in Gang- Won, Ok-Cheon in Chung-Buk, Ham-Yang in Gyeong-Nam in Korea from May until October in 2011. Hence, the research surveyed these farmers about production cost, management cost, input labors and materials, land price and etc. by working process to calculate production and operation cost. As the result of farm survey, the result of the analysis shows income rate 27.76%, B/C Ratio 2.5, and NPV 121,830,831 won in $16,500m^2$ with 10 years period when local price of Rhus verniciflura is 2,200,000 won/3.75 kg at locals with 3% discount rate is applied. Therefore, starting open field cultivation of Rhus verniciflura, which requires intensive labor or expanding the cultivation area needs more labor force.

• International Area Studies Review
• /
• v.13 no.1
• /
• pp.39-51
• /
• 2009

The misery index is the sum of the inflation rate and the unemployment rate. The higher the index, the lower the performance of the national economy. Lee and Cheong (2007) propose that the open misery index, defined to be the sum of the misery index and the ratio of current account to GDP, properly measure the economic performance of a national economy when its degree of openness is large. This paper shows that the periods of rising open misery index of the USA coincide with those of economic hardship in the USA. Most recently, the open misery index of the USA has shown a rising trend for a decade prior to the current economic crisis. That is, external and internal imbalances of the USA have accumulated for a decade prior to the current economic crisis. We interpret the recent rising trend of the open misery index of the USA as a precursor of the current economic crisis.

• Progress in Superconductivity and Cryogenics
• /
• v.14 no.4
• /
• pp.12-15
• /
• 2012

$MgB_2$ superconductor is highly sensitive to the Mg content. Even if the samples are synthesized with the appropriate looking stoichiometric ratio, the heat treatment leads to the loss of Mg either to ambiance or to MgO. To avoid it, either excess Mg is added in the starting powder or sealed ampoule annealing is employed. In this paper the effect of open Mg sintering ambiance on the ex-situ $MgB_2$ was studied to enhance its superconducting properties. The open Mg ambiance was created to avoid any overpressure of Mg by providing a hole in Fe tube used as sample holder. The decrease in resistivity of the synthesized sample was observed through the increased temperature dependence of electron-phonon interactions. A clear enhancement in the superconducting cross-sectional area and hence the in-field critical current density is obtained.

• Journal of the Korean association of regional geographers
• /
• v.18 no.1
• /
• pp.118-127
• /
• 2012

Using GIS, animal clinic's spatial distribution characteristics were analyzed. Animal clinic location data was collected through the Internet's Open API service. Approximately 4,100 animal clinics are operated in South Korea in 2011. And 47 % of these are located in the Seoul area. Population, especially female population and apartment resident's ratio affects the location factor of the animal clinic. The number of 25~44 year-old woman and animal clinics are high correlation. In the animal clinic location, distance from the road is more important than the distance of the metro.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.25 no.2
• /
• pp.197-205
• /
• 2001

It is possible to examine the costume of Chosun era that tombs excavated in chonnam area, have contained various kinds of clothes. There are six tombs in which costumes have been excavated in Chonnam provinces. One(Go un) is tomb of the early years of Chosun Dynasty and the other tombs is those of the middle years of Chosun Dynasty(16∼17 century). There were many kinds of Po which was called Jickryung, Danryung, Chullik, Dappo, Jangui, So-changui etc, and contained chechori, skirts, under-trousers in tombs. But there are not see Kuui, Dopo that excavated in other area. Chullik showed the features of winkle, sleeves and the ratio of length. Dappo was only to be seen in a Go uns grave. Mens chechori collar(kit) was called Mokpankit in all, and womans chechori collar was called Kalkit or Tangkokit. The length of chechori was different according to the times. Most trousers are types of underwear and also there are Sapok tousers, open trousers. The characterstics of excavated costumes are not regional feature but trend of the times. The costumes excavated in Chonnam area are similiar to those excavated in other area at the same times.

• Journal of Korean Society of Forest Science
• /
• v.89 no.3
• /
• pp.452-460
• /
• 2000

This study was to investigate the growth characteristics, physiological adaptation of Pinus densiflora(Japanese Red Pine) seedlings at the artificial canopy gap in the Quercus acutissima plantation and to analyze its natural regeneration mechanism. Photosynthetic and transpiration rates were analyzed by different levels of photosynthetically active radiation and by seedling growth. Comparing to seedlings at the open area, those at the canopy gap showed more growth in height than in diameter with different levels of light quality and low light intensity, and the increase rate of dry weight was higher in the aboveground than in the underground, maintaining relatively high T/R rate. The C/F(the ratio of non-photosynthetic organs to photosynthetic organs in dry weight) of the aboveground at the canopy gap was higher than that at the open area by 0.1~0.2, while light saturation and light compensation points at the canopy gap were lower than that at the open area by $300{\mu}mol\;m^{-2}s^{-1}$ and 40%, respectively. The seedlings appeared to have shade tolerance to a certain extent at the young growth stage despite Pinus densiflora is typically classified shade-intolerant species. With light intensity lower than $400{\sim}450{\mu}mol\;m^{-2}s^{-1}$, photosynthetic rate and water use efficiency relatively increased by effective use of light energy.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.1434-1437
• /
• 2003

Sometimes open holes are required for the function and the weight reduction of structure and machinery. However, the serious stress concentration occurs because of the geometric discontinuity caused by the holes and cutting section. In this study, it is attempted to obtain the stress concentration coefficients of the inner surface of the hole boundary by changing the position and the shape of holes on the homogeneous isotropic plate. And the effects on the plate are investigated. The results show that the stress level becomes low and the distribution area widens the position of stress concentration changes as the ratio a/b increases and change to a circle. And as the ratio a/l decreases, the stress concentration reduces. As the plate with three holes. the stress $\sigma$$\_$x/ and $\tau$$\_$xy/ of hole 1,3 becomes high, especially $\sigma$$\_$x/ dominant and high.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2002.10a
• /
• pp.833-836
• /
• 2002

Sometimes open holes are required for the function and the weight reduction of structure and machinery. However, the serious stress concentration occurs because of the geometric discontinuity caused by the holes and cutting section. In this study, it is attempted to obtain the stress concentration coefficients of the inner surface of the hole boundary by changing the position and the shape of holes on the homogeneous isotropic plate. And the effects on the plate are investigated. The results show that the stress level becomes low and the distribution area widens the position of stress concentration changes as the ratio ah increases and change to a circle. And as the ratio a/l decreases, the stress concentration reduces.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1996.04a
• /
• pp.333-336
• /
• 1996

This paper is an exploratory study aimed at finding factors that influence the penetration of cellular mobile telecommunications which have seen rapid development since 1980s. The paper tries to find economy and policy variables to influence the penetration by means of the multiple regression analysis. This paper shows a model that explain the penetration ratio of cellular service. The model is based on data from 39 upper middle income and 39 high income countries. The result shows that GDP per capita and the service period of the cellular mobile telecommunication have influenced on the penetration ratio positively, and the tariff of the service negatively. But, it is the open area to study the impact of the telecommunications policy changes on penetration, and to set a model which could explain the nation-specific characteristics.