• Korean Journal of Environmental Agriculture
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• v.34 no.3
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• pp.223-229
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• 2015

BACKGROUND: It is important to understand residual patterns of pesticides applied on crops for ensuring their safety in agricultural products. However, there are few studies on the residual patterns of pesticides in minor crops, which are small in cultivation area. In this study, residual amounts of bifenthrin and chlorfenapyr sprayed on perilla leaf as a minor crop were investigated to know their residual patterns. METHODS AND RESULTS: Bifenthrin and chlorfenapyr were sprayed 2 or 3 times on perilla leaves at a week interval prior to harvest, and the perilla leaves were collected at 0, 1, 3, 5 and 7 days after the final application of pesticides. Recoveries for residual analysis of pesticides spiked on perilla leaves with concentrations of 0.1 and 0.5 mg/kg were 81.9-104.8%. The residual amounts of pesticides interpreted using first order kinetics model show that dissipation constants of bifenthrin and chlorfenapyr in perilla leaves were 0.0724-0.0535 and $0.0948-0.0821day^{-1}$, respectively. In addition, the dissipation half-lives in perilla leaves were 9.6-12.9 days for bifenthrin and 7.3-8.4 days for chlorfenapyr. When pre-harvest residue limits (PHRL) of bifenthrin and chlorfenapyr at 10 days before harvest calculated on the basis of the dissipation constants and maximum residue limits of the pesticides were calculated as 17.1 for bifenthrin and 15.9 mg/kg for chlorfenapyr. CONCLUSION: Therefore, the PHRL calculated using the time-dependant residual patterns of pesticides in perilla leaves and their regression analysis may be used as experimental evidences in order to ensure the safety of pesticides in perilla leaves before harvest.

• Journal of Korean Society of Steel Construction
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• v.16 no.2 s.69
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• pp.257-265
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• 2004

The aim of this study is to investigate the inelastic buckling behavior of the beams under moment gradient using a line-type finite element method. The method is incorporated the non-uniform yielding of the cross-section caused by the presence of residual stress and accepted model of residual stress so called 'simplified' and 'polynomial' pattern is adopted in this study. The inelastic lateral-torsional buckling results obtained in this study is compared with the buckling results obtained from the design method based on the allowable stress method given in Korean Steel Designers Manual (KSDM 1995). This study have found that the design method in KSDM (1995) is conservative without and with intermediate bracing applied at the mid span of the beam, and there is some scope for improving the provisions of KSDM (1995)

• Conservation Science in Museum
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• v.2
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• pp.51-55
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• 2000

This study is an analysis of residual fatty acid of the unidentified 26 fish bone samples which were excavated from Bupchon-ri in Wonju, Kangwon province. The purpose of this study is to identify fish kind by comparing the residual fatty acid analysis with the reference data of croaker, shark, herring and weakfish. Fatty acid was separated by gas chromatography and distribution pattern was analyzed by calculating composition of each sample. Principal component analysis(PCA), one of multivariate analysis method was used to understand fatty acid distribution data.

• Journal of Korea Foundry Society
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• v.40 no.1
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• pp.1-6
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• 2020

Many studies involving a thermal stress analysis using computational methods have been conducted, though there have been relatively few experimental attempts to investigate thermal stress phenomena. Casting products undergo thermal stress variations during the casting process as the temperature drops from the melting temperature to room temperature, with gradient cooling also occurring from the surface to the core. It is difficult to examine thermal stress states continuously during the casting process. Therefore, only the final states of thermal stress and deformations can be detemined. In this study, specimens sensitive to thermal stress, were made by a casting process. After which the residual stress levels in the specimens were measured by a hole drilling method with Electron Speckle-Interferometry technique. Subsequently, we examined the thermal stresses in terms of deformation during the casting process by means of a numerical analysis. Finally, we compared the experimental and numerical analysis results. It was found that the numerical thermal stress analysis is an effective means of understanding the stress generation mechanism in casting products during the casting process.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.28 no.4
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• pp.385-397
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• 1992

Current measurements at 3 sections and numerical experiments were carried out in Masan Bay to understand the effect of the wind on the residual currents and pollutant transport. The vertical distribution of horizontal velocities were directly affected by the wind at the depths of 1m and 2m beneath the sea surface. Analysis of the velocity data suggested that changes in the vertical gravitational circulation contributed to the net circulation. The net transport of water through the northern part of the bay was observed to be landward, with wind-induced transport of about 100m super(3)/s. Hence, wind is concluded to be the dominant mechanism driving the net circulation in the northern area of Masan Bay. Numerical experiments are shown that when S wind with 5m/s blew, northern area of the bay was generated the horizontal circulation of clockwise and local gyre. On the contrary of those, N wind made her to the anti-clockwise. In the case of no wind, the tidal residual current(constant flow) is very small or neglected except the bay-mouth. The inflow or outflow pattern of the mouth is considered as the flows generated by tidal residual current only. The distance of wind-induced transport of pollutant was as long as 2 times of no wind during the one tidal period.

• Journal of Industrial Technology
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• v.19
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• pp.25-29
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• 1999

Rotary bending fatigue tests were carried out to investigate the fatigue behavior of high performance ductile cast iron experienced super rapid induction heat treatment. The effect of super rapid induction treatment on fatigue limit was experimentally examined with the special focus on the variation surface microstructure and the fatigue crack initiation and propagation through fractography. Main results obtained are as follows. By super rapid induction treatment in FCD500, the martensite structure obtained through conventional quenching heat treatment was confirmed on the specimen surface. The fatigue crack initiation in the hardened surface layer was restricted by the martensite structure and compressive residual stress. Thus, it could be interpreted that the initiation stress would be increased by the improvement of surface structure. The fatigue crack propagation in the hardened layer was retarded by the presence of the globular shape martensite around the graphite nodule and compressive residual stress. The crack propagation path has shown zigzag pattern in the hardened surface layer.

• The Korean Journal of Physiology
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• v.25 no.1
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• pp.81-85
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• 1991

At the fifth day after right lung pneumonectomy in New-Zealand white rabbits $(0.8{\sim}1.1\;kg\;B.W.)$, phospholipid and protein concentration in the left lung lavage fluid were measured for clarification of the effect of unilateral pneumonectomy on the secretory function of the type II pneumocytes in growing rabbits. In an attempt to evaluate the effect of unilateral pneumonectomy on the compensatory growth of the residual lung, left lung weight and left lung weight-body weight ratio and DNA concentration, RNA/DNA and total DNA content in the left lung tissue were measured in pneumonectomized and in sham operated control rabbits. The lung weight of pneumonectomized rabbit was approximately two times heavier than that of the control rabbits. DNA concentration and RNA/DNA of the lung tissue were not changed but total DNA content was increased significantly. Phospholipid concentration in the lung lavage fluid of the pneumonectomized rabbits was over two times higher than that of control rabbits. from these experimental results, It is concluded that unilateral pneumonectomy in growing rabbits might cause to increase the secretion of pulmonary surfactant from type II pneumocyte of the residual lung. The cellular hyperplasia seems to be the primary response of the compensatory growing lung in unilateral pneumonectomized growing rabbits.

• Transactions of Materials Processing
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• v.18 no.3
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• pp.268-273
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• 2009

Ultraviolet nanoimprint lithography (UV-NIL), which is performed at a low pressure and at room temperature, is known as a low cost method for the fabrication of nano-scale patterns. In the patterning process, maintaining the uniformity of the residual layer is critical as the pattern transfer of features to the substrate must include the timed etch of the residual layer prior to the etching of the transfer layer. In pursuit of a thin and uniform residual layer thickness, the initial volume and the position of each droplet both need to be optimized. However, the monomer mixtures of resin had a tendency to evaporate. The evaporation rate depends on not only time, but also the initial volume of the monomer droplet. In order to decide the initial volume of each droplet, the accurate prediction of evaporation behavior is required. In this study, the theoretical model of the evaporation behavior of resin droplets was developed and compared with the available experimental data in the literature. It is confirmed that the evaporation rate of a droplet is not proportional to the area of its free surface, but to the length of its contact line. Finally, the parameter of the developed theoretical model was calculated by curve fitting to decide the initial volume of resin droplets.

• Progress in Superconductivity and Cryogenics
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• v.17 no.1
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• pp.17-20
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• 2015

Coated conductor is an important candidate for power cable applications due to its high current density. Even for DC power cable transmission, we must study the transport properties of HTS tapes after slow and fast discharge. In order to evaluate relation of the magnetic field with applied current we developed a scanning magnetic field measurements system by employing a Hall probe. This work presents the measurements of the magnetic fields above a coated conductor by varying applied current pattern. In the work, a transport current of 100 A, less than the critical current, is applied to YBCO coated conductor. We measured the residual magnetic field distributions after cut off the transport current with slow and fast operations. The results show differences of the magnetic field profiles and the corresponding current profiles by an inverse solution from the magnetic field measurement between these two operations because of the hysteresis of coated conductor excited by the transport current.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.5 s.113
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• pp.50-55
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• 2005

In previous report, we investigated the impact of hexeneuronic acid and some residual extractiveson lignin determination. These non-lignin components severely interfered lignin content determination which also affect on the oxygen delignification comparison between aspen and pine unbleached kraft pulps. Very different pattern was observed whether based on uncorrected conventional kappa number or based on corrected kappa number in oxygen delignification comparison. Lower kappa number aspen pulps showed poor response to oxygen delignification when kappa number was used as lignin determination method but better response with using the acid lignin method. Phenolic hydroxyl group in kraft pulps were also compared based on uncorrected or corrected kappa numberfor lignin content. Based on uncorrected kappa number, lower kappa number oxygen-delignified pulps had lower phenolic hydroxyl group. However, lower kappa number oxygen-delignified pulps showed much higher phenolic hydroxyl group based on the corrected lignin content. For accurate comparison for residual lignin properties from different pulps, lignin determination should be corrected from non-lignin components contribution to lignin.