• Journal of Korean Society of Environmental Engineers
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• v.22 no.12
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• pp.2205-2213
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• 2000

To investigate removal efficiency of dissolved matter by NF and RO, a pilot plant was operated for six months using groundwater treated by UF membrane. After the pilot plant operation, we performed autopsy test to identify characteristics of foulant attached on the membrane surface applying the used NF and RO in the pilot plant test. In autopsy test, we measured permeate flux and recovery rate of flux by chemical cleaning in each membrane. We also analyzed chemical cleaning disposal to examine component of foulant. Permeate flux of NF and RO1 showed rapid decline after 100 days of operation. Especially, reduction of specific flux in RO1 was more serious than in NF. Specific flux of RO2 with a low recovery rate resulted in gradual flux decline. Removal efficiencies of dissolved inorganic matters as a conductivity were 76.3%, 88.2% and 95.3% respectively for NF, RO1 and RO2, and RO2 presented the highest removal efficiency. And those of dissolved organic matters as TOC were about 80% for both NF and RO. The specific flux of membranes declined gradually from the feed water inlet to outlet of the membrane module and it showed that membrane fouling increased along the feed flow direction. Namely, concentration of pollutants became higher and volume of feed water was less as the feed flow approached to the outlet. It seemed that major foul ants were Ca consolidated into inorganic material and Si consolidated into organic material on the membrane surface. Fe was a great contribution to irreversible fouling. The SEM results indicated that the organic matter was attached to the first layer, closer to the membrane, and then inorganic matter with tetragonal shape layered over them. We could not observe biofouling because microorganism, which was cause of biofouling, was almost pretreated in UF membrane.

• Resources Recycling
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• v.15 no.2 s.70
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• pp.3-9
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• 2006

As a basic study on the conversion of molten converter slag to the ordinary portland cement, the effects of $Al_{2}O_{3}$ addition on the interface reaction between solid CaO and molten converter slag has been studied. Alumina added converter slag whose basicity was controlled to 1 and 2 was melted and hold for 30 minutes in MgO crucible at $1500^{\circ}C$. Then sintered CaO pellet heated at the same temperature was dipped into the molten slag and held for 30minutes. After the reaction, the crucible was cooled in air and the specimen was cut off to the horizontal direction of the crucible. The dissolution rate of CaO pellet with the addition of $Al_{2}O_{3}$ was measured by the change of the radius or sintered CaO pellet and the interface layer was observed by SEM/EDX. As a result. At the basicity 2 slag, thickness of created $C_{3}S$ layer increased 3.5 times and quantity of $C_{6}AF_{2}\;or\;C_{4}AF$ phase increase 2 times than baisicy 1 slag.

• Journal of the Microelectronics and Packaging Society
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• v.15 no.2
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• pp.37-45
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• 2008

In this study, reliabilities of Cu (60 um)/SnAg (20 um) double-bump flip chip assemblies were investigated for the flip chip interconnections on organic substrates with 100 um pitch. After multiple reflows at $250^{\circ}C\;and\;280^{\circ}C$, bump contact resistances were almost same regardless of number of reflows and reflow temperature. In the high temperature storage test, there was no bump contact resistance change at $125^{\circ}C$ up to 2000 hours. However, bump contact resistances slightly increased at $150^{\circ}C$ due to Kirkendall voids formation. In the electromigration test, Cu/SnAg double-bump flip chip assemblies showed no electromigration until about 600 hours due to reduced local current density. Finally, in the thermal cycling test, thermal cycling failure mainly occurred at Si chip/Cu column interface which was found out the highest stress concentration site in the finite element analysis. As a result, Al pad was displaced out under thermal cycling. This failure mode was caused by normal compressive strain acting Cu column bumps along perpendicular direction of a Si chip.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.587-599
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• 2018

In building-integrated photovoltaic (BIPV) systems, power generation functions are integrated into building functions by installing solar modules in combination with building materials. While this integration appears to be attractive, a design method is needed to achieve maximum power generation. Previously, the influence of the design elements on power generation was analyzed by computer simulations and demonstration tools. On the other hand, problems remain due to the inaccuracy of power generation analysis and relationship analysis, and limited demonstration. To solve this problem, this paper proposed the use of an extended demonstration mock-up. The mock-up was designed and constructed by implementing the design elements of the module types, installation angles, and direction. The actual operation data for one year were analyzed to evaluate the effects of the design elements on power generation. These results can be used to determine the feasibility of future BIPV systems and the optimal selection of system design elements.

• The Journal of the Korea Contents Association
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• v.20 no.3
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• pp.1-9
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• 2020

The purpose of this study is to verify the effects of ventilation corridor and derive adequate policy alternatives to its application for the city of Sejong, which is located in an inland of Korean Peninsula. In order to introduce the ventilation corridor in the city, it is necessary both to understand change on fresh air flow affected by the construction of new cities and to show its effects which are able to circulate air flow of the city. The study identified ventilation effects using computational fluid dynamics models. In particular, it analyzed change on wind speed and direction after constructing of a new town and cool air flow along the lowlands generated after sunset. In addition, it identified those of reducing particulate matter when arranging buildings conforming to the ventilation corridor at block level. The policy implications derived from simulation can be summarized as follows. First, it is desirable to plan ventilation corridors so that fresh air from mountains, forests, and valleys can flow into cities and mitigate the concentration of particulate matter. Furthermore, public facilities covering parks, plazas, and playgrounds should be installed preferentially to attract safe outdoor activities near to areas with low levels of particulate matter. Finally, it is adequate to prepare for a number of alternative plans by analyzing ventilation corridors when setting out district unit plan.

• Journal of Korean Medical classics
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• v.9
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• pp.381-429
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• 1996

Choo-Joo(鄒澍;1790-1844) was the medicine scholar who lived in the late peroid of the Chung-Dynasty and wrote "Bon-Kyung-So-Jeung(本經疏證)", "Bon-kyung-Sok-So(本經續疏)", "Bon-Kyng-Seo-So-Yo(本經序疏要)". In the books mentioned above, He annotated the chief effectiveness of herbal medicine(本草) which had been presented on "Shin-Nong-Bon-Cho-Kyung(神農本草經)" and "Myoung-Eui-Byul-Lok(名醫別錄)". He defined medical action of 315 herb-items with the many theories of various scholars. Scholars whom Choo-Joo has qoutated belong to the school of study of Chinese classics, and they have regarded "Hwang-Je-Nae-Kyung(黃帝內經)", "Shin-Nong-Bon-Cho-Kyung(神農本草經)" and "Sang-Han-Lon(傷寒論)" as great important cannon and have lived during the Myoung Chung Dynasty. The distinctive character of Choo-Joo belongs to similar academic traditions. It seems that he was appected mainly by "Bon-Cho-Gang-Mok(本草綱目)" written by Lee-Si-Jin(李時珍), Mok-Jung-Soon(繆仲淳)'s "Sin-Nonng-Bon-Cho-Kyung-So(神農本草經疏)", You-Yak-Guem(劉若金)'s "Bon-Cho-Sul(本草述)" and Yang-Si-Tae(楊時泰)'s "Bon-Cho-Sul-Gu-Won(本草述鉤元)". He contributed in two big sides. First, Choo-Joo(鄒澍) have achieved much contribution in biliographical study of Chinese classics(考證學). He analyzed the medical theory of herb-medicine, combining with "Nae-Kyung(內經)", "Sang-Han-Lon(傷寒論)" and many theory of various scholars in order to make research on the chief effectiveness that had been presented in "Shin-Nong-Bon-Cho-Kyung(神農本草經)". Therefore the practical application of medical theory and term which had been represented on classics were offered. Secondary, Choo-joo did great accomplishment in pharmacology. The point of his theory was grasping the effect of a medicine through distinctive one beyond general feature. He set up standards that grasp distintive feature as form, color, energy and taste, place of production and temper. And on the basis of these standards he investigated distinctive feature on various fields, then he induced 'the Uem-Yang-0-Haeng Theory(陰陽五行說)' from distictions. According to the these method of classification, form(形) stand for the resultant shape of herbal function, color(色) represent the active direction of herb, energy and taste(氣味) imply the ultimate active function of herb, the place of production(産地) and the period of occurrence(發生時期) symbolize symptoms. When he applied these method to seek for effetiveness, he regarded the field which revealed most representative feature as of great importance, and Combining remained distinctions with one another, he determined more accurate medicinal value. These method of obsevation solved contradiction which occured by equaly appling all medical herbs for the regular standard. The most important theory that represented in Choo-Joo(鄒澍) is to induce and to certify the distintive feature of herb into the 'Uem-Yang-0-Haeng Theory'. That is, concluded as "spring(生), growing(長), change(化), collecting(收) and storing(藏)". As the results of these studies, he made clear the action of medicine more concretly and made 'the Uem-Yang-0-Haeng Theory(陰陽五行說)' more concret and actual for applying. And he contrbuted to establish the standard for grasping the effect of medicines.

• Journal of the Korean Magnetics Society
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• v.11 no.1
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• pp.21-25
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• 2001

$\alpha$-Fe$_2$O$_3$ thin films were prepared on Si substrate by a pulsed laser deposition system and characterized by X-ray and Mossbauer spectroscopy. The appropriate conditions of pulsation was the power of 5.128 W/cm2 at on oxygen pressure of 0.1 Torr at a substrate temperature of 30$0^{\circ}C$. After that the film was heated at 80$0^{\circ}C$ for 1 day. The particles shape deposited on the film was ellipsoidal and the average length and width were 200~300 nm, 70~150 am respectively. The crystal structure was conformed to be of corundums symmetry with the hexagonal unit cell having a lattice constant of u = 5.03$\pm$0.05 $\AA$, c = 13.735$\pm$0.05 $\AA$. The average angles between the atomic spin and the magnetic hyperfine field of Fe ion were 38$^{\circ}$and 48$^{\circ}$ at above and blow the Morin transition temperature respectively. The Morin transition was found to occur at the temperature ranges from 200 K to room temperature and atomic spin direction was assumed to change from 48$^{\circ}$ to 80$^{\circ}$in respect to the c-axis.

• Journal of the Korean Magnetics Society
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• v.9 no.5
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• pp.251-255
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• 1999

NiFe(60 $\AA$)/Co(0$\AA$$\leq$x$\AA$$\leq$15$\AA$)/Cu(60$\AA$)/Co(30$\AA$) spin valve thin films were prepared on 4$^{\circ}$ tilt-cut Si(111) substrates with a 50 $\AA$ thick Cu underlayer without applying any external magnetic field during the deposition, and the effects of inserted ultrathin Co layer on magnetic anisotropy and GMR properties of the NiFe(60 $\AA$)/Cu(60$\AA$)/Co(30$\AA$) spin valves were investigated. As the ultrathin Co layer was inserted into the NiFe/Cu interface of the spin valves, GMR ratio was increased from about 1.5% to 3.5%, and the easy axis of NiFe(60 $\AA$) layer was rotated by 90$^{\circ}$. Accordingly, it was aligned along the same direction with the easy axis of Co(30 $\AA$)layer. Therefore, squared R-H curves was obtained in the spin valves, which is favorable properties for the digital GMR devices such as MRAM. In order to investigate the change of magnetic anisotropy of NiFe layer of the spin valves in more details,XRD measurement was performed using NiFe(500 $\AA$) and NiFe(500 $\AA$)/Co(10 $\AA$) thin films on the same templates. Strong (220) NiFe peak was observed in both films regardless of the inserted Co layer, so it was thought that the variation of magnetic anisotropy of NiFe layer is from the interface effect, the change of interface from NiFe/Cu to NiFe/Co, rather than the volume effect such as the change of magnetocrystalline effect.

• Journal of Wetlands Research
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• v.11 no.2
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• pp.77-87
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• 2009

Drought has different characteristics from other disasters. Say, drought effect can be prolonged according to drought duration and so the estimation of drought damage can be difficult. Therefore this study suggested and applied the proper drought damage estimation method developed based on previous methods. The suggested method was used for the drought damage estimations considering agricultural aspect and domestic water use which the data are available. We estimated drought damages on Gimhae-si, Namhae-gun, Uiryeong-gun, Changnyeong-gun, and Changwon-si in Gyungsang Nam-do from 2006 to 2008. As a result, in agricultural aspect, the damage on rice was about 195million won in Uiryeong-gun and on rice was about 67million won in Changnyeong-gun. In domestic water use, the damage was about 21billion won on 4 towns of Namhae-gun when we assumed the expense for sufferance is 400,000 won. We may need develope the method in the direction of the best use of present data for the improvement of the suggested method in agricultural aspect. In the case of the estimation of drought damage about domestic water use, we could suggest more realistic method if we consider the weights for the expense for sufferance and water use.

• Resources Recycling
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• v.14 no.5 s.67
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• pp.13-17
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• 2005

As a basic study for recycling molten converter slag as an ordinary portland cement (OPC) by a conversion process, the reaction mechanism and the rate of the formation of $C_4AF$ which is one of the main components of OPC were investigated. The converter slag whose basicity was controlled by adding reagent grade $SiO_2$ was melted and hold for 30 minutes in MgO crucible at $1300^{\circ}C{\sim}1350^{\circ}C$. Then, the sintered CaO pellet heated at the same temperature was dipped into the molten slag and hold for $10{\sim}30$minutes. After the reaction, the crucible was cooled in air and the specimen was cut off to the horizontal direction of the crucible. The dissolution rate of $C_3A$ pellet was measured by the change of radius of the sintered $C_3A$ pellet, and the formed phase of $C_4AF$ was observed by SEM/EDX. As a result, the dissolution rate of $C_3A$ pellet into molten slag was increased from $0.75{\times}10^{-4}(cm/sec)$ at $1300^{\circ}C$ to $1.67{\times}10^{-4}(cm/sec)$ at $1350^{\circ}C$, and the mixed layer of $C_4AF$ and $C_{12}A_7$ was found between slag and $C_3A$ pellet.