• Journal of Soil and Groundwater Environment
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• v.11 no.4
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• pp.18-24
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• 2006

The possibility of multiresidue analysis of 24 pesticides out of 30 residual pesticides which are subjected to test in the golf courses was examined. The utility of multiresidue method for pesticide residue test was evaluated by recovery test through a standard addition method of pesticides in water, soil, and lawn grass. The experimental results of the recovery test for individual pesticides are as follows : The number of pesticide of which average recovery rate was over 70% regardless of media was 16 pesticides. These pesticides were composed of 8 organophosphorus pesticides (chlorpyrifos, chlorpyrifosmethyl, diazinon, EPN, fenitrothion, phenthoate, phosalone, and toclofos-methyl). 4-organochlorinated pesticides (daconil, captan, endosulfan, and tetradifon), 2-pyrethroid pesticides(fenpropathrin, lambda-cyhalothrin) and 2 other pesticides (bromopropylate, pendimethalin). On the other hand, in case of dicofol, average recovery rate was over 70% for water and lawn grass but only 53.3% for soil. Therefore, the multiresidue method applied in this experiment is not appropriate for analysis of dicofol in soil. Furthermore, among 7 pesticides, 2 pesticides(amitraz and pyraclofos) showed that theirs average recovery rate deviated from criteria($70{\sim}130%$) in almost ail media, while 5 pesticides(bensulide, deltamethrin, iprodione, phosphamidon and tralomethlin) were not detected from all media by GC/NPD or GC/ECD.

• Herbal Formula Science
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• v.24 no.2
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• pp.80-99
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• 2016

Objectives : Instrumental chemical analysis was utilized to investigate the effect of Add-Omit-Saenghyeoryunbu-eum(AO-SHU) on diabetic treatment. One of the most exciting, yet also controversial, arguments is the safety and biological mechanisms of the natural medicine on human body. Therefore, the aim of this study is to provide a better understanding on bioactive chemical components, hazards of heavy metal contamination and biological mechanism of the diabetic medicine composed of 12 different natural herbs. Methods : To study bioactive compound and metallic component in the diabetic medicine in detail, LC-MS/MS (Liquid Chromatography-Mass/Mass), GC (Gas Chromatography) and ICP (Inductively Coupled Plasma) were utilized to characterize the extract of the diabetic medicine and the result was compared with 18 marker substances selected from literature survey. In addition, in vitro assay experiments including GPR 119 activity and human DGAT-1 inhibition, and OGTT (Oral Glucose Tolerance Test) were performed to verify the effectiveness of this medicine on diabetic treatment. Results : Out of 18 marker substances, 9 bioactive compounds were identified from LC-MS/MS analysis which include Citruline, Catalpol, Berberine, Ginsenoside Rb1, Ginsenoside Rg1, Oleanolic acid, β-Sitosterol, Mangiferin, and Schizandrin. ICP study on 245 residual pesticides revealed that 239 species were not detected but 6 species, Dimethomorph, Trifloxystrobin, Pyraclostrobin, Isoprocarb, Carbaryl and Flubendiamide, while the amounts are trace levels, below permitted concentrations. The biological activity was observed in vitro assay and Oral Glucose Tolerance Test(OGTT), which are consistent with a preliminary clinical test result, a drop in blood sugar level after taking this herbal medicine. Conclusions : Instrumental chemical analysis using LC-MS/MS, GC, and ICP was conducted successfully to identify bioactive compounds in AO-SHU for the treatment of diabetes, finding 9 bioactive compounds. Furthermore, in vitro assay experiments and OGTT show that AO-SHU has its biological activities, which imply that it can be a candidate for the future diabetes remedy.

• Journal of the Korea Concrete Institute
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• v.22 no.2
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• pp.149-158
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• 2010

Recently, numerous construction techniques for repairing and strengthening methods for above ground or air exposed concrete structure have been developed. However repairing and strengthening methods for underwater structural members under continuous loading, such as piers and steel piles need the further development. Therefore, this study develops an aqua epoxy, which can be used for repairing and strengthening of structural members located underwater. Moreover, using the epoxy material and strengthening fibers, a fiber reinforced composite sheet called Aqua Advanced FRP (AAF) for underwater usage is developed. To verify and to obtain properties of the material and the performance of AAF, several tests such as pull-off strength test, bond shear strength test, and chemical resistance test, were carried out. The results showed that the developed aqua epoxy does not easily dissolve in wet conditions and does not create any residual particle during hardening. In spite of underwater conditions, it showed the superior workability, because of the high viscosity over 30,000 cps and adhesion capacity over 2 MPa, which are nearly equivalent to those used in dry conditions. In case of the chemical resistance test, the developed aqua epoxy and composite showed the weight change of about 0.5~1.0%, which verifies the superior chemical resistance.

• Journal of Korea Water Resources Association
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• v.39 no.12 s.173
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• pp.997-1012
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• 2006

We have presented a nonparametric stochastic approach for the SOI(Southern Oscillation Index) series that used nonlinear methodology called Nonlinear AutoRegressive(NAR) based on conditional kernel density function and CAFPE(Corrected Asymptotic Final Prediction Error) lag selection. The fitted linear AR model represents heteroscedasticity, and besides, a BDS(Brock - Dechert - Sheinkman) statistics is rejected. Hence, we applied NAR model to the SOI series. We can identify the lags 1, 2 and 4 are appropriate one, and estimated conditional mean function. There is no autocorrelation of residuals in the Portmanteau Test. However, the null hypothesis of normality and no heteroscedasticity is rejected in the Jarque-Bera Test and ARCH-LM Test, respectively. Moreover, the lag selection for conditional standard deviation function with CAFPE provides lags 3, 8 and 9. As the results of conditional standard deviation analysis, all I.I.D assumptions of the residuals are accepted. Particularly, the BDS statistics is accepted at the 95% and 99% significance level. Finally, we split the SOI set into a sample for estimating themodel and a sample for out-of-sample prediction, that is, we conduct the one-step ahead forecasts for the last 97 values (15%). The NAR model shows a MSEP of 0.5464 that is 7% lower than those of the linear model. Hence, the relevance of the NAR model may be proved in these results, and the nonparametric NAR model is encouraging rather than a linear one to reflect the nonlinearity of SOI series.

• Korean Journal of Food Science and Technology
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• v.20 no.2
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• pp.272-279
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• 1988

Kinetics of ascorbic acid destruction and browning were evaluated by the dynamic test using actual drying data in order to apply in the optimization of food dehydration. Radish was chosen as a test material because it has many typical quality characteristics during drying. Radish was dried in the cabinet dryer with being measured in moisture, food temperature, ascorbic acid and browning. Using moisture and temperature history, proposed kinetic model was integrated and parameters of the model were searched by the iteration scheme to show minimum discrepancy between predicted and experimental data. Ascorbic acid destruction and browning were represented by first and zero order reaction respectively. Arrhenius equation was used to describe temperature dependence. Several mathematical functions of moisture dependence were compared in the model simplicity and residual sum of square. Attained kinetic models were analyzed as functions of temperature and moisture. Rate of ascorbic acid destruction was low at high moisture content, increased with moisture decrease to show a maximum at the moisture of $9{\sim}12g/g$ dry solid, and then decreased up to full dryness. Browning rate increased with moisture decrease to show a sharp maximum at $4{\sim}6g/g$ dry solid and decreased with further moisture decrease.

• Journal of the Korean Arthroscopy Society
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• v.13 no.2
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• pp.138-142
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• 2009

Purpose: The purpose of this study was to evaluate the result of anterior cruciate ligament (ACL) reconstruction using a fourstrand single semitendinous tendon to decrease the donor site morbidity due to harvest both semitendinosus and gracilis tendon. Materials and Methods: Thirty seven consecutive patients who had underwent ACL reconstruction using four-strand single semitendinosus tendon were evaluated. Mean age was 28.6 years old. Male was 34, female 3 patients. Time from injury to surgery was 5.4 months. Combined injuries were 10 meniscus injuries, 3 medial collateral ligament injuries and 1 osteochondral injury. Mean follow-up period was 16 months(12~18 months). Clinical evaluation was done using range of motion, Lachman test, pivot-shift test, Lysholm score & KT-2000 arthrometer. Results: All patients showed the normal range of motion of mean 150..at follow-up. Lachman test and pivot-shift test was negative in 35 cases. Lysholm score was improve from 84 to 92. Two cases had residual laxity due to poor compliance. Mean anterior translation compared to contralateral side by KT-2000 arthrometer improved from 6.7 mm preoperatively to 2.1 mm at follow-up. Conclusion: Reconstruction of the anterior cruciate ligament with use of a four-strand single semitendinosus tendon autograft showed good clinical results.

• Journal of the Korean Geotechnical Society
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• v.24 no.9
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• pp.13-21
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• 2008

Partitioning tracer method is a useful tool to characterize large domains of the aquifers contaminated with light nonaqueous phase liquids (LNAPLs). Sorption of the partitioning tracers to the organic matter content of soil can potentially influence the efficacy of partitioning tracer method. LNAPL-water partitioning coefficients of tracers ($K_{nw}$), measured by static method, showed linear relationship. Sorption isotherm tests were conducted to evaluate the sorption capacity of the soils packed in the columns and the results were appropriately represented by Freundlich sorption isotherm. The sorption of tracers proportionally increased with the increase of the organic matter content of the soil. Laboratory experiments were conducted in four columns each packed with soils of different organic matter contents to determine the potential interference effects of sorption to soil organic matter content and correction factors for the errors in estimation of LNAPLs by partitioning tracer method. Though there were no contaminants added, breakthrough curves from columns packed with mixture of Jumunjin standard sand and organic matter showed separation of tracers. Columns were then contaminated to residual saturation with kerosene and breakthrough curves were obtained. The results show that sorption of tracers to soil organic matter leads to an increase in the retardation factor (R) and hence, to an overestimation of the saturation of LNAPLs. A relation between the percentage of organic matter content and the corresponding percentage error in the estimation of NAPLs has been developed.

• Nuclear Engineering and Technology
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• v.56 no.3
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• pp.803-811
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• 2024

Nuclear accidents such as Fukushima Daiichi have highlighted the potential of passive safety systems to replace or complement active safety systems as part of the overall prevention and/or mitigation strategies. In addition, passive systems are key features of Small Modular Reactors (SMRs), for which they are becoming almost unavoidable and are part of the basic design of many reactors available in today's nuclear market. Nevertheless, their potential to significantly increase the safety of nuclear power plants still needs to be strengthened, in particular the ability of computer codes to determine their performance and reliability in industrial applications and support the safety demonstration. The PASTELS project (September 2020-February 2024), funded by the European Commission "Euratom H2020" programme, is devoted to the study of passive systems relying on natural circulation. The project focuses on two types, namely the SAfety COndenser (SACO) for the evacuation of the core residual power and the Containment Wall Condenser (CWC) for the reduction of heat and pressure in the containment vessel in case of accident. A specific design for each of these systems is being investigated in the project. Firstly, a straight vertical pool type of SACO has been implemented on the Framatome's PKL loop at Erlangen. It represents a tube bundle type heat exchanger that transfers heat from the secondary circuit to the water pool in which it is immersed by condensing the vapour generated in the steam generator. Secondly, the project relies on the CWC installed on the PASI test loop at LUT University in Finland. This facility reproduces the thermal-hydraulic behaviour of a Passive Containment Cooling System (PCCS) mainly composed of a CWC, a heat exchanger in the containment vessel connected to a water tank at atmospheric pressure outside the vessel which represents the ultimate heat sink. Several activities are carried out within the framework of the project. Different tests are conducted on these integral test facilities to produce new and relevant experimental data allowing to better characterize the physical behaviours and the performances of these systems for various thermo-hydraulic conditions. These test programmes are simulated by different codes acting at different scales, mainly system and CFD codes. New "system/CFD" coupling approaches are also considered to evaluate their potential to benefit both from the accuracy of CFD in regions where local 3D effects are dominant and system codes whose computational speed, robustness and general level of physical validation are particularly appreciated in industrial studies. In parallel, the project includes the study of single and two-phase natural circulation loops through a bibliographical study and the simulations of the PERSEO and HERO-2 experimental facilities. After a synthetic presentation of the project and its objectives, this article provides the reader with findings related to the physical analysis of the test results obtained on the PKL and PASI installations as well an overall evaluation of the capability of the different numerical tools to simulate passive systems.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.3 s.55
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• pp.127-134
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• 2009

This study investigated their properties of spalling resistance and residual compressive strength after fire test corresponding to various ISO, RABT heating curves, and contents of hybrid organic fiber of high strength concrete. The results were summarized as following. As fundamental characters of concrete with hybrid organic fiber, the flowability was directly declined as the increase of fiber contents, and air contents were decreased or increased a little bit, but there was not big difference. The compressive strength was gradually declined sluggishly at 28 days. As properties of fire resistance, in case of RABT heating curves, compare with ISO heating curves a spalling aspect showed till range that has much contents of hybrid organic fiber, but they are mostly peeling spalling, which means spalling aspect didn't happen to inside. In conclusion, in case of W/B 25% high strength concrete, the spalling was prevented over 0.04% of contents of fiber at ISO heating curve and over 0.10% of contents of fiber at the RABT heating curve. In case of spalling was prevented, mass reduction rate according to the change of heating temperature curves showed around 7% at ISO heating curves and around 9% at RABT heating curves. The residual compressive strength rate corresponding to the change of heating temperature curves showed 50%~60% at ISO heating temperature curves and 30%~35% at RABT heating temperature curves in case of spalling was prevented.

• Korean journal of applied entomology
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• v.52 no.4
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• pp.415-425
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• 2013

The yellow tea thrips, Scirtothrips dorsalis (Thysanoptera: Thripidae), has been regarded as a minor pest on citrus on Jeju Island. However, the damage of yellow tea thrips has gradually increased since 2007. This study was conducted to develop a forecasting model for generation peak time of S. dorsalis by using degree-days. Simple linear regression analysis was applied to determine the relationship between the generation number (x, dependent variable) and degree-days (y, independent variable). As a result, two regression models were established: citrus-based model (y = 310.9x + 69.0, $r^2$=0.99) and green tea-based model (y = 285.7x + 84.1, $r^2$=0.99). The models was fitted by independent data sets obtained from 2013 and evaluated using the technique of RSS (residual sum of square) and ${\chi}^2$-test. The green tea based-model showed a good fitting ability. The discrepancy between model outputs and actual data, and the practical application of models were discussed.