• Journal of Soil and Groundwater Environment
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• v.6 no.4
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• pp.61-72
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• 2001

A barrier liner system is placed at the bottom and side slope in landfill to protect a leaking of leachate that the hydraulic conductivity of this system should be less than It 107cm/sec. In this study, the soil-bentonite mixture for the bottom liner system was evaluated in two point of views : changing characteristics of the hydraulic conductivity according to the different mixing ratio of soil-bentonite with the effect of bentonite swelling and the difference method (A & D type) of compaction on the hydraulic conductivity. As the results, maximum dry density (${\gamma}$$_{dmax}$) of SC group mixture was higher than of CL group mixture. However, the result of optimum moisture contents(OMC) of both groups were the contrary. In case of ${\gamma}$$_{dmax}$ by different compaction method, D type was higher than A. But the OMC were the contrary. The difference of ${\gamma}$$_{dmax}$ according to the Compaction energy, “SC” group mixture W3S higher than the “CL” group. In case of OMC of “CL” group was higher than “SC” group. The effecting of swelling was a little bit different on the two factors. According to the result of compaction test, the use of site soil only could not meet the criteria on hydraulic conductivity, but could find a solution for the mixing ratio of bentonite mixture were satisfied to the standard of barriation. The increased in bentonite mixing ratio and degree of swelling, the values of hydraulic conductivity were decreased. Especially the “CL” group with “D” type compaction measured the lowest value with the same conditions. Also, the bentonite mixing ratio has more influenced on the hydraulic conductivity compare with swelling effect. The “SC” group mixture with “A” typo compaction got a big difference from others. The evaluation of economic for the construction cost on the two cases, the lower bentonite mixing ratio of soil-bentonite mixed soil is more economically because of bentonite cost.

• Journal of Soil and Groundwater Environment
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• v.12 no.2
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• pp.9-19
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• 2007

This study investigated the interaction between groundwater and stream water systems, which is caused by the artificial weir on streambed, enforcing external stresses on the groundwater system. The study area is in Nami Natural Recreation Woods located in Chungcheongnam-do Geumsan-gun Nami-myeon Geoncheon-ri. In this study both of hydrophysical methods (hydraulic head) and hyrdochemical investigations (pH, EC, major ion analysis) were applied. In order to identify the relationship between each of study results, cross-correlation analysis is performed. From results of hydrophysical methods, water level fluctuation at BH-14, installed by the weir, shows the double-recession pattern much more frequently and much higher amplitudes than the fluctuation at each of other monitoring wells. Using the results by hydrochemical investigations, hydrochemical properties at BH-14 is similar to the hydrochemical characteristics in stream water. To analyze the interrelationships between the results from each of applied methods, cross-correlation analysis was applied. Results from the correlation analyses, water levels at BH-14 and stream weir showed the highest cross-correlation in hydrophysical aspects. On the other hand, the correlation between stream weir and bridge was the highest in hydrochemical aspects. The difference between the results from each of methods is due that the hydrophysical response at BH-14, such as water level, is induced by the pressure propagation-not with mass transfer, but the hydrochemical interaction, caused by mass transport, takes much more times. In conclusion impermeable artificial weir on streambed changes the interfacial condition between the stream and surrounding aquifers. The induced water flux into the groundwater system during flood period make water level at BH-14 increase instantly and groundwater quality higly similar to the quality of stream water. Referred similarities in both of water level and water quality at BH-14 become much higher when water level at weir grow higher.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.1
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• pp.8-15
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• 2003

If contaminated river water is sprayed over a floodplain, the microbial processes can simultaneously remove organic matter and nitrogen during the infiltration through the sediment profile. The effect of rhizosphere on the removal of organic matter and nitrogen from contaminated river water was investigated using floodplain lysimeters. River water was sprayed at a rate of $68.0L\;m^{-2}\;d^{-1}$ on the top of the lysimeters with or without weed vegetation on the surface, Concentrations of $NO_3$, $NH_4$ and dissolved oxygen (DO), and chemical oxygen demand (COD) and Eh in water were measured as functions of depth for 4 weeks after the system reached a steady state water flow and biological reactions. A significant reductive-condition for denitrification developed in the 30-cm surface profile of lysimeters with weeds. At a depth of 30 cm, COD and $NO_3$-N concentration decreased to 5.2 and $0.9mg\;L^{-1}$ from the respective influent concentrations of 18.2 and $9.8mg\;L^{-1}$. The removal of $NO_3$ in lysimeters with weeds was significantly higher than in those without weeds. Vegetation on the top was assumed to remove $NO_3$ directly by absorption and to create more favorable conditions for denitrification by supply of organic matter and rapid $O_2$ consumption, In the lysimeters without weeds, further removal of $NO_3$ was limited by the lack of an electron donor, i.e. organic matter. These results suggest that the filtration through native floodplains, which include rhizospheres of vegetation on the surface, can be effective for the treatment of contaminated river water.

• Radiation Oncology Journal
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• v.24 no.4
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• pp.255-262
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• 2006

$\underline{Purpose}$: To evaluate the pathological prognostic factors related to local recurrence after radical surgery and adjuvant radiation therapy in advanced rectal cancer. $\underline{Materials\;and\;Methods}$: Fifty-four patients with advanced rectal cancer who were treated with radical surgery followed by adjuvant radiotherapy and chemotherapy between February 1993 and December 2001 were enrolled in this study. Among these patients, 14 patients experienced local recurrence. Tissue specimens of the patients were obtained to determine pathologic parameters such as histological grade, depth of invasion, venous invasion, lymphatic invasion, neural invasion and immunohistopathological analysis for expression of p53, Ki-67, c-erb, ezrin, c-met, phosphorylated S6 kinase, S100A4, and HIF-1 alpha. The correlation of these parameters with the tumor response to radiotherapy was statistically analyzed using the chi-square test, multivariate analysis, and the hierarchical clustering method. $\underline{Results}$: In univariate analysis, the histological tumor grade, venous invasion, invasion depth of the tumor and the over expression of c-met and HIF-1 alpha were accompanied with radioresistance that was found to be statistically significant. In multivariate analysis, venous invasion, invasion depth of tumor and over expression of c-met were also accompanied with radioresistance that was found to be statistically significant. By analysis with hierarchical clustering, the invasion depth of the tumor, and the over expression of c-met and HIF-1 alpha were factors found to be related to local recurrence. Whereas 71.4% of patients with local recurrence had 2 or more these factors, only 27.5% of patients without local recurrence had 2 or more of these factors. $\underline{Conclusion}$: In advanced rectal cancer patients treated by radical surgery and adjuvant chemo-radiation therapy, the poor prognostic factors found to be related to local recurrence were HIF-1 alpha positive, c-met positive, and an invasion depth more than 5.5 mm. A prospective study is necessary to confirm whether these factors would be useful clinical parameters to measure and predict a radio-resistance group of patients.

• Korean Journal of Weed Science
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• v.30 no.1
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• pp.1-16
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• 2010

This study was conducted to develope identification method with major broad leaved weed seedlings. Characteristics of weed seedlings were investigated at two to four true leaf stage. Qualitative characteristics were more useful to identification of weed species than quantitative characteristics at the seedling stage. Many species were elliptic and broadly elliptic type in their cotyledon shape. Cotyledon shape of Cassia nomame and Calystegia sepium were broadly oblong. Four species were transverse broadly elliptic in their cotyledon shape. Rumex japonicus, Persicaria hydropiper, Euphorbia supina and Acalypha australis have three or more types in their cotyledon shape. Cotyledons of Vigna angularis var. nipponensis remained below ground after its germination. Many species were round in apex and were cuneate in base of cotyledon. Humulus japonicus and Polygonum aviculare were sessile in cotyledon base. The second true leaf shape of some species changed after first leaf stages. Glycine soja, V. angularis var. nipponensis and Kummerowia striata were broadly ovate, heart-shaped, orbicular or broadly obovate in their first true leaf, respectively, but the second true leaf shape of them were tripalmately compound. Aeschynomene indica and Cassia nomame were paripinnately compound leaf in their first and second true leaves. Margin of true leaves were entire in many species but six species including Xanthium occidentale were dentate in their true leaf margins. Margin of Euphorbia supina was entire in first true leaf and dentate in second true leaf. Margin of Chenopodium album and C. serotinum were entire in their first true leaf stage and erose in their second true leaf stage. The key for weed seedling identification of major weed species were made based on quantitative and qualitative morphological characteristics.

• Journal of the Korean Wood Science and Technology
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• v.19 no.1
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• pp.31-63
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• 1991

It was proved that in conventional kiln drying of disks piling position in the kiln exerted a great influence on drying rates, and the larger the variation of disk diameter, the more undulating drying rates of disks. While in vacuum drying disks there was no influence on drying rates. By the end-wrapping treatments and the radial direction of disks tangential surface stresses in the core of disks were slightly compressive in three species. In control disks the drying stresses distributed into one step-style that compressive stresses in the pith side of 6cm from pith were larger than those in the bark side, while in the disks end-wrapped with Korean paper the drying stresses distributed uniformly, because flow rates of free water in disks had no difference between heart-and sap-wood by obstruction of evaporating water from surface of disks by end-wrapping with Korean paper. And end-wrapping with Korean paper considerably restrained those. Tangential differential shrinkage stresses developed the maximum tensile stress near the bark and with approaching the pith the stresses gradually reduced and changed into compressive stresses in near the pith. At the end of vacuum drying the maximum tangential tensile stresses of disks end-wrapped with Korean paper were smaller than those of control disks, and critical moisture contents causing the V-shaped crack of disks end-wrapped with Korean paper were lower than those of control disks because of the set by obstruction of evaporating water of end-wrapping with Korean paper. In the experiment of vacuum drying stress distribution the disks end-wrapped with Korean paper or aluminum foil in three species were free from V-shaped cracks and control disks were defected very slightly by V-shaped cracks. And also disks end-wrapped with Korean paper were free from heart checks in Alnus japonica and Juglans sinensis, and heart checks were occurred very slightly in others. Especially, not to speak of disks end-wrapped with Korean paper, vacuum drying of disks end-wrapped with aluminum foil prevented effectively drying defects, moreover drying times could be shortened, that is. Ginkgo biloba, Alnus japonica, and Juglans sinensis disks could be dried from green to in-use moisture content in 110 hours, 272 hours, and 407 hours, respectively.

• Journal of Chest Surgery
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• v.31 no.6
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• pp.553-559
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• 1998

Introduction: The most dramatic application of hypothermia in cardiac surgery is in deep hypothermic circulatory arrest(DHCA). Because man in natural circumstances is never exposed to this extreme hypothermic condition, one of the controversial aspects of clinical hypothermia is appropriate acid-base management($\alpha$-stat versus pH-stat). This study aims to compare $\alpha$-stat with pH-stat for: (1) brain cooling and re-warming speed during hypothermia induction and re-warming by cardiopulmonary bypass (CPB); (2) cerebral perfusion, metabolism, and their coupling; and (3) the extent of development of cerebral edema after circulatory arrest, in young pigs. Materials & Methods: Fourteen young pigs were assigned to one of two strategies of gas manipulation. Cerebral blood flow was measured with a cerebral venous outflow technique. After a median sternotomy, CPB was established. Core cooling was initiated and continued until nasopHaryngeal temperature fell below $20^{\circ}C$. The flow rate was set at 2,500 ml/min. Once their temperatures were below $20^{\circ}C$, the animals were subjected to DHCA for 40 mins. During cooling, acid-base balance was maintained according to either $\alpha$-STAT or pH-STAT strategies. After DHCA, the body was re-warmed to normal body temperature. The animals were then sacrificed, and their brains measured for edema. Cerebral perfusion and metabolism were measured before the onset of CPB, before cooling, before DHCA, 15 mins after re-warming, and upon completion of re-warming. Results & Conclusion: Cooling time was significantly shorter with $\alpha$-stat than with pH-stat strategy, while there were no significant differences in rewarming time between the two groups. Nosignificant differences were found in cerebral blood flow, metabolic rate, or flow/ metabolic rate ratio between two groups. Temperature-related differences were significant in cerebral blood flow, metabolic rate, and flow/metabolic rate ratio within each group. Brain water content showed no significant differences between two groups.

• Journal of Chest Surgery
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• v.42 no.3
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• pp.324-330
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• 2009

Background: The long term patency of the free saphenous vein graft, which is the most commonly used conduit, anastomosed to the ascending aorta has been reported to be lower than that of arterial grafts. We evaluated early clinical outcome and the angiographic patency of the saphenous vein composite graft based on the left internal thoracic artery, and compared these results with those of using arterial composite grafts. Material and Method: From September 2006 to October 2008, 419 patients underwent off-pump coronary revascularization. Among those, 295 patients (70.4%) were revascularized using composite grafts (group I: saphenous vein composite graft, n=71, group II: arterial composite graft, n=224). The clinical results were compared between the 2 groups. Early postoperative coronary angiograms were performed in all the patients. ($1.6{\pm}1.6$ days) Result: The number of the distal anastomosis per patient was $3.5{\pm}1.0$ and $3.1{\pm}0.8$ in group I and II, respectively (p=.002). The operative mortality (n=2, 0.7%) and postoperative complications such as atrial fibrillation (n=73, 24.7%), perioperative myocardial infarct (n=6, 2.0%), acute renal failure (n=6, 2.0%), reoperation for bleeding (n=5, 1.7%), cerebrovascular accident (n=3, 1.0%), and mediastinitis (n=1, 0.3%) were not related with the use of saphenous vein graft. Early coronary angiograms revealed a 96.9% (126/130) for the saphenous vein grafts and a 98.8% (479/485) for the composite graft in group II (p=.231). Conclusion: Our data suggested that a saphenous vein graft might be used as analtemative conduit to the arterial graft for constructing a composite graft, as based on our early clinical and angiographic results. Further study is required to establish the long-term efficacy of using a saphenous vein as a composite graft.

• Land and Housing Review
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• v.6 no.2
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• pp.67-77
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• 2015

Now that it is the current situation that the smooth supply and demand are necessary for 2nd phase of beginning construction and stable development of Gaesung Industrial Complex, this study was willing to offer the planning criteria and model to establish the lodging for the workers in Gaesung Industrial Complex based on the agreement that both South and North Korea agreed in 2007. Regarding the plan, its standard and the alternative were reviewed considering welfare of workers, economic efficiency, technical validity, possibility of agreement and long-term development. The exclusive area per capita was calculated through Labor Standards Act of Korea and status survey of lodging for the workers provided to border line area between China and North Korea and the economic alternative based on one room for 6 persons with the public restroom was compared with that of development type based on one room for 4 persons with indoor restroom. Especially regarding the proposed site, the area with the optimized position was set by considering gradient, accessibility and convenience of development out of the area of Dongchang-ri where was agreed already and the priority of the proposed site that can keep the existing building site and provide was offered. The necessary period for whole construction was set as approximately 36 months. Regarding construction method, RC Rahmen method was selected as the optimized alternative considering the workmanship of manpower of North Korea and conditions of supply and demand of materials and cluster-type vehicle allocation plan based on 4~6 units considering the efficiency of supplying service facilities and convenient facilities along the simultaneous accommodation of 15,000 people was offered. It was analyzed that total business expenses of approximately 80~100 billion Korean Won would required though there were the difference for each alternative in the charged rental way that the development business owner develops by lending the inter-Korea Cooperation Fund and withdraws the rent by the benefit principle. The possibility of withdrawing the rent was analyzed assuming that the period of withdrawing the investment is 30 years. Especially for the operation management after moving, the establishment of the committee of operating the lodging for the workers of Gaesung Industrial Complex (tentative name) was offered with the dualized governance that the constructor takes charge of operational management, collecting fees and management of infrastructure and human resource management is delegated to North Korea.

• Journal of the Mineralogical Society of Korea
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• v.16 no.2
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• pp.135-149
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• 2003

Domestic zeolite ores are mostly composed of Ca-type clinoptilolite, accompanying a little amounts of mordenite. However, other types of zeolite ores rich in ferrierite, heulandite, or mordenite are less commonly found. Based on the quantitative XRD analysis, zeolite contents are determined to be nearly 50∼90 wt%. Impurities (mostly ＞ 10 wt%) in the zeolite ores chiefly consist of quartz, feldspar, smectite, and opal-CT. The determined CEC values ($CEC_{AA}$ ) of powdery samples (grain size: < 125 $\mu\textrm{m}$) of zeolite ores by the Ammonium Acetate method are mostly higher than 100 meq/100 g. Some zeolites from the Guryongpo area, corresponding to the clinoptilolite ore, are measured to be dominantly high in CEC values ranging 170∼190 meq/100 g. Cation exchange property of the zeolite ores varies greatly depending on the types or zeolite species present in the ores. Despite of the lower grade in zeolite content, the $CEC_{AA}$ of ferrierite ore is comparatively high. Compared to this, the $CEC_{AA }$ of heulandite ore is very low, though the zeolite ore exhibits the highest grade ranging up to about 90 wt%. In addition, the CEC values calculated theoretically from the framework composition of clinoptilolite-heulandite series are not consistent with those determined by the cation exchage experiment. The measured $CEC_{AA}$ of clinoptilolite ores are generally higher than those of heulandite ores. This may be due to the higher Ca abundance in exchangeable cation composition and the presence of probable stacking faults in heulandite. The variation of $CEC_{CEC}$ is roughly proportional, though not strictly compatible, to the zeolite contents in clinoptilolite ores. It seems to be caused by the fact that the $CEC_{AA}$ of clinoptilolite locally varies depending on crystal-chemical diversity, i. e., the variation in framework composition (Si/Al) and exchangeable cation composition (especially, the contents of Ca and K). In addition, the determined CEC values ($CEC_{MB}$ ) of zeolite ores by the Methylene Blue method are much higher than those calculated from smectite contents. It suggests a probable reaction of Methylene Blue ion ($C_{16}$ $H_{18}$ $N_3$S+) with larger-pore zeolites than clinoptlolite-heulandite series, i.e., ferrierite and mordenite as well as with smectite. This can be supported by the fact that the ferrierite ore accompanying little amount of smectite has the highest value in CE $C_{MB}$ .