• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.5
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• pp.543-548
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• 2006

After allergic contact dermatitis (ACD) elicited by application of 1 mL of 2.5% 1-chloro-2,4-dinitrochloro-benzene (DNCB) onto dorsal skin, Sprague Dawley male rats fed Scutellaria baicalensis water extract were observed to investigate the mitigative effect of Scutellaria baicalensis water extract on ACD. The Scutellaria baicalensis water extract (100 mg/kg/day) was daily administered to rats suffered from ACD. Concentrations of TBARS in plasma and liver were increased in rats with ACD. The concentrations of TBARS in liver were significantly decreased in Scutellaria baicalensis-fed group (SBFG) compared to control group (CG), but not in plasma. Liver SOD activity was significantly increased in SBFG compared to that of normal group and CG. Serum Ig E level was significantly increased in CG compared to normal group, while that of SBFG was significantly decreased. The epidermal thickness of CG was significantly increased compared to that of normal group, while that of SBFG was significantly decreased compared to that of CG. These results indicated that the Scutellaria baicalensis water extract administration was effective for antioxidative activity in liver, serum Ig E level and epidermal thickness of rats with ACD.

• The Korean Journal of Pesticide Science
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• v.12 no.3
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• pp.302-306
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• 2008

This study was performed to investigate the contact toxicity, fumigant toxicity, and synergistic effect using agricultural materials (AM) when mixed with selected essential oils against oak longicorn beetle, Moechotypa diphysis. Four kinds of AM, namely, chungkiller, ungsalta, jinap, purunjunsa showed 100% contact toxicity at one day after treatment. Subsequently, four AM was tested the fumigant toxicity during 24 hours. At concentration of 1 mL, jinap and chungkiller showed 100% mortality at 3 hr after treatment, prunjunsa and ungsalta showed 100% mortality at 6 hr after treatment. When applicate to the small vinyl bag (15 L), all AM (50 mL/15 L) was showed 100% mortality. Jinap showed the mortality 100% when mixed pennyroyal oil with the ratio of 5+1. It was higher than single treatment.

• Journal of Astronomy and Space Sciences
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• v.27 no.2
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• pp.89-96
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• 2010

BVR CCD observations of GW Cep were made on 15 nights in November through December 2008 with a 1-m reflector at the Jincheon station of the Chungbuk National University Observatory. Nineteen new times of minimum lights for GW Cep were determined and added to a collection of all other times of minima available to us. These data were then intensively analyzed, by reference to an O-C diagram, to deduce the general form of period variation for GW Cep. It was found that the O-C diagram could be interpreted as presenting two different forms of period change: an exclusively quasi-sinusoidal change with a period of 32.6 years and an eccentricity of 0.10; and a quasi-sinusoidal change with a period of 46.2 years and an eccentricity of 0.36 superposed on an upward parabola. Although a final conclusion is somewhat premature at present, the latter seems more plausible because late-type contact binaries allow an inter-exchange of both energy and mass between the component stars. The quasi-sinusoidal characteristics were interpreted in terms of a light-time effect due to an unseen tertiary component. The minimum masses of the tertiary component for both cases were calculated to be nearly the same as the $0.23-0.26M\;{\odot}$-ranges which is hardly detectable in a light curve synthesis. The upward parabolic O-C diagram corresponding to a secular period increase of about $4.12{\times}10^{-8}\;d/yr$ was interpreted as mass being transferred from the lesser to more massive component. The transfer rate for a conservative case was calculated to be about $2.66\;{\times}\;10^{-8}\;M_{\odot}/yr$ which is compatible with other W UMa-type contact binaries.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.1
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• pp.13-29
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• 2001

A mathematical model was proposed to analyze the vibration of diaphragm, such as the contact lenses fitted on the eyes, being subjected to the external sinusoidal pressure. The model incorporates the differential equations and their numerical solution program, based on the wave equations. Turbo-C and graphic software, formulated to describe the dependence of the various parameters involved in the vibration. The model predicts the radial distribution of amplitude, frequency dependence of both average displacement amplitude and the power of diaphragm whose edge is being either simply supported or rigidly clamped in vibration. The effect of variables such as thickness, radius, damping coefficients on the vibration characteristics was illustrated by the computer simulation of the derived program. As the frequency of driving pressure increases above the certain value determined by the boundary conditions and parameters the wave shape or pattern changes from simple arc to belly or loops having double antinode. It seems that the effect of outer antinode progressively increases as the frequency increases. If this kind of phenomena occurs to the contact lens on the cornea in vivo, it may cause an abnormal correction power in the lenses or pull off the eye due the increased rise of outer part of the lens.

• Composites Research
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• v.16 no.3
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• pp.25-31
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• 2003

In this work the effect of surface treated SiC on thermal stability and mechanical interfacial properties of carbon fiber/epoxy resin composites. The surface properties of the SiC were determined by acid/base values and contact angles. The thermal stabilities of carbon fiber/epoxy resin composites were investigated by TGA. The mechanical interfacial properties of the composites were studied in ILSS, critical stress intensity factor ($\textrm{K}_{IC}$), and critical strain energy release rate($\textrm{G}_{IC}$) measurements. As a result, the acidically treated SiC(A-SiC) had higher acid value than untreated SiC(V-SiC) or basically treated SiC(B-SiC). According to the contact angle measurements, it was observed that chemical treatments led to an increase of surface free energy of the SiC surfaces, mainly due to the increase of the specific(polar) component. The mechanical interfacial properties of the composites including ILSS, $\textrm{K}_{IC}$, and $\textrm{G}_{IC}$ had been improved in the specimens treated by chemical solutions. These results were explained that good wetting played an important role in improving the degree of adhesion at interfaces between SiC and epoxy resin matrix.

• International Journal of Highway Engineering
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• v.8 no.4 s.30
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• pp.13-24
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• 2006

The stresses in concrete pavement systems are larger when vehicle loads are applied at pavement edges, and these large stresses significantly affect the behavior and performance of pavements. Therefore, in this study, the stress distribution and the critical stresses in concrete pavements were investigated using a finite element model when dual-wheel single-, tandem-, and tridem-axle loads were applied at pavement edges. First, the stress distribution along the longitudinal and transverse directions was analyzed, and then the effects of slab thickness, concrete elastic modulus, and foundation stiffness on the stress distribution were investigated. The effect of the tire contact pressure related to the tire print area was also studied. The location of the critical stress occurrence in concrete pavements was finally investigated. From this study, it was found that the critical concrete stress due to edge loads became larger as the concrete elastic modulus increased, the slab thickness increased, and the foundation stiffness decreased. The effect of the tire contact pressure on the critical stress was clear as the slab thickness became smaller. The critical stress location in the transverse direction was independent of the concrete elastic modulus and the foundation stiffness; however, it moved into the interior as the slab thickness increased. The critical stress location in the longitudinal direction was under the axle for single- and tandem-axle loads, but for tridem-axle loads, it tended to move under the middle axle from the outer axles as the concrete elastic modulus and/or slab thickness increased and the foundation stiffness decreased.

• Membrane Journal
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• v.22 no.5
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• pp.369-380
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• 2012

A one-dimensional numerical model based on the energy and mass equations have been developed to predict the trans membrane water vapor flux and thermal efficiency under various operating conditions in Direct Contact Membrane Distillation (DCMD) process. The model validation have been carried out by experimental data from literature and showed good agreement. The effect of operating parameters such as brine inlet temperature and velocity, and distillate inlet temperature and velocity to increase water vapor flux and thermal efficiency were predicted by the steady-state model. The results showed that the inlet temperature and velocity in brine side are dominant factors to control the water vapor flux and thermal efficiency because the effect of inlet temperature and velocity in brine side showed the higher water vapor flux and thermal efficiency than that of inlet temperature and velocity in distillate side. The water vapor flux was increased 3.4 times in the range of 21.22 $kg/m^2h$ to 71.26 $kg/m^2h$ and the thermal efficiency was increased 37.5% in that of 0.556 to 0.765 with increasing brine inlet temperature from $60^{\circ}C$ to $95^{\circ}C$. Meanwhile, the water vapor flux was increased 30% in that of 27.91 $kg/m^2h$ to 36.33 $kg/m^2h$ and thermal efficiency increased 7.5% in that of 0.6 to 0.646 as the brine inlet velocity was increased from 60 m/h to 300 m/h.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.6
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• pp.803-810
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• 2013

The purpose of this research is to analyze the effect of shape of the inductive textile electrode on the non-contact heart activity sensing, based on the magnetic-induced conductivity principle. Four types of the inductive textile electrodes were determined according to the combinations of the two shape features. A fiber-metal hybrid-typed conductive thread was developed and applied to materialization of the textile electrodes by embroidery method. The heart activity was extracted through the textile electrode sewn on a T-shirt. The experiments were implemented to constantly measure the heart activity for 20 seconds, in each case of 5 healthy male subjects. The heart activity signals acquired in each type of the inductive textile electrode were analyzed, 1)by drawing a comparison of morphology with those of ECG signal (LeadII), and 2)by calculation of the normalized mean and standard deviation of magnitude of the heart activity signals. The analysis resulted that the relatively better quality of signals were acquired in the 'square' types in the matter of whole shape, while the better results were obtained in 'donut' types in the matter of center hole. Accordingly, the relatively best quality of signals was obtained in the case of 'Square-Donut' type of the inductive textile electrode.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.409-416
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• 2020

The seismic performance of a containment structure should be secured to maintain the structural soundness of a containment structure under various earthquakes that occur globally. Therefore, an analysis of the seismic performance of a modular containment structure for a small modular reactor is also required. To analyze the seismic performance of modular containment, FEM models with contact surfaces between the modules and tendon were prepared and the modal and seismic analyses were performed. The displacement, stress, and gap size of modular containment under earthquake wave were analyzed. The effects of the tendon force, friction coefficient, and earthquake wave on the seismic performance were analyzed. The seismic performance of monolithic containment was also analyzed for comparison. In the 1st and 2nd natural modes, which most likely affect, the modular containment showed horizontal dynamic behavior, which is similar to monolithic containment, because of the combined effects of the tendon force and friction force between modules. When the combined effect is sufficient, the seismic performance of the modular containment is secured over a certain level. An additional increase in seismic performance is expected when some material with a larger friction coefficient is adopted on the contact surface.

• Journal of Korea Entertainment Industry Association
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• v.15 no.1
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• pp.191-197
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• 2021

This study studied the effect of visual difference on balance and walking ability in college students' life care. The study was conducted on 45 students attending H University in G City, divided into control groups (n=22, not wearing glasses and contact lenses) and experimental groups (n=23, wearing glasses and contact lenses). In not wearing glasses and contact lenses, the subjects measured visual acuity with logMAR charts, evaluated their balance ability with BIOrescue, and evaluated walking ability with G-Walk. The results of this study showed that the experimental group had statistically significantly lower vision than the control group in the visual acuity measurement(p<.01). Static balance ability was statistically significant increase in center of mass movement of the right foot in the experimental group compared to the control group(p<.05). Dynamic balance ability was statistically significantly reduce in limit of stability for groups of experiments compared to control group(p<.05). The walking ability was statistically significantly shorter on step length and stride length, swing of the experimental group compared to the control group in the right foot(p<.05). The findings showed that the visual difference in university students reduces balance and walking ability. Therefore, university students with poor visual acuity are recommended to correct of visual acuity to prevent collision and falls in their daily lives.