• Korean Journal of Poultry Science
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• v.44 no.4
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• pp.267-274
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• 2017

This study was conducted to investigate the effect of feeding with dietary silicate based complex mineral (SCM) on the performance of laying hens. SCM at five levels (0%, 0.2%, 0.4%, 0.6% and 0.8%) was added to commercial diets, and fed to four hundred fifty Hy-Line Brown from fifty four to sixty five weeks of age. Egg production increased as the addition of dietary SCM to basal diets increased up to 0.6% (P<0.05). Furthermore, Feed intake increased in a manner similar to that of egg production (P<0.05). However, there was no difference in feed efficiency among the treatments. Eggshell thickness and breaking strength were significantly higher for the chickens fed with SCM than control from sixty weeks old to the end of experiment (P<0.05). Similarly, albumen height and Haugh unit were significantly higher for the chickens fed with SCM compared to those of control group (P<0.05). AST of birds fed SCM showed significantly higher than control (P<0.05). However, blood neutral fat level tended to increase in SCM treatments. Moreover, bone mineral density increased with SCM addition up to 0.4% (P<0.05). IL-2 (Interleukin-2) and IL-6 (Interleukin-6) levels appeared to be improved in the chickens fed with SCM addition diets, although not statistically different from all treatments. The results of this study indicated that the optimum SCM for improving the performance, egg quality and immunological competence of laying hens from 54 to 65 weeks of age was 0.6%.

• Tunnel and Underground Space
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• v.13 no.1
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• pp.52-63
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• 2003

Discontinuities such as faults, fractures and joints in rock mass play the dominant role in the mechanical and hydraulic properties of the rock mass. The key factors that influence on the flow of groundwater are hydraulic and geometric characteristics of discontinuities and their connectivity. In this study, a program that analyzes groundwater flow in the 3D discontinuity network was developed on the assumption that the discontinuity characteristics such as density, trace length, orientation and aperture have particular distribution functions. This program generates discontinuities in a three-dimensional space and analyzes their connectivity and groundwater flow. Due to the limited computing capacity In this study, REV was not exactly determined, but it was inferred to be greater than 25$\times$25$\times$25 ㎥. By calculating the extent of aperture that influences on the groundwater flow, it was found that the discontinuities with the aperture smaller than 30% of the mean aperture had little influence on the groundwater flow. In addition, there was little difference in the equivalent hydraulic conductivity for the the two cases when considering and not considering the boundary effect. It was because the groundwater flow was mostly influenced by the discontinuities with large aperture. Among the parameters considered in this study, the length, aperture, and orientation of discontinuities had the greatest influence on the equivalent hydraulic conductivity of rock mass in their order. In case of existence of a fault in rock mass, elements of the equivalent hydraulic conductivity tensor parallel to the fault fairly increased in their magnitude but those perpendicular to the fault were increased in a very small amount at the first stage and then converged.

• Korean Journal of Remote Sensing
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• v.34 no.2_1
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• pp.237-248
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• 2018

The vertical distribution of hydrometeor before precipitation near the cloud base has been analyzed using a scanning lidar, rawinsonde data, and Cloud-Resolving Storm Simulator (CReSS). This study mostly focuses on 13 Desember 2016 only. The typical synoptic pattern of lake-effect snowstorm induced easterly in the Yeongdong region. Clouds generated due to high temperature difference between 850 hPa and sea surface (SST) penentrated in the Yeongdong region along with northerly and northeasterly, which eventually resulted precipitation. The cloud base height before the precipitation changed from 750 m to 1,280 m, which was in agreement with that from ceilometer at Sokcho. However, ceilometer tended to detect the cloud base 50 m ~ 100 m below strong signal of lidar backscattering coefficient. As a result, the depolarization ratio increased vertically while the backscattering coefficient decreased about 1,010 m~1,200 m above the ground. Lidar signal might be interpreted to be attenuated with the penetration depth of the cloud layer with of nonspherical hydrometeor (snow, ice cloud). An increase in backscattering signal and a decrease in depolarization ratio occured in the layer of 800 to 1,010 m, probably being associated with an increase in non-spherical particles. There seemed to be a shallow liquid layer with a low depolarization ratio (<0.1) in the layer of 850~900 m. As the altitude increases in the 680 m~850 m, the backscattering coefficient and depolarization ratio increase at the same time. In this range of height, the maximum value (0.6) is displayed. Such a result can be inferred that the nonspherical hydrometeor are distributed by a low density. At this time, the depolarization ratio and the backscattering coefficient did not increase under observed melting layer of 680 m. The lidar has a disadvantage that it is difficult for its beam to penetrate deep into clouds due to attenuation problem. However it is promising to distinguish hydrometeor morphology by utilizing the depolarization ratio and the backscattering coefficient, since its vertical high resolution (2.5 m) enable us to analyze detailed cloud microphysics. It would contribute to understanding cloud microphysics of cold clouds and snowfall when remote sensings including lidar, radar, and in-situ measurements could be timely utilized altogether.

• Investigative Magnetic Resonance Imaging
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• v.8 no.1
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• pp.42-49
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• 2004

Purpose : The quantization noise in magnetic resonance imaging (MRI) systems is analyzed. The signal-to-quantization noise ratio (SQNR) in the reconstructed image is derived from the level of quantization in the signal in spatial frequency domain. Based on the derived formula, the SQNRs in various main magnetic fields with different receiver systems are evaluated. From the evaluation, the quantization noise could be a major noise source determining overall system signal-to-noise ratio (SNR) in high field MRI system. A few methods to reduce the quantization noise are suggested. Materials and methods : In Fourier imaging methods, spin density distribution is encoded by phase and frequency encoding gradients in such a way that it becomes a distribution in the spatial frequency domain. Thus the quantization noise in the spatial frequency domain is expressed in terms of the SQNR in the reconstructed image. The validity of the derived formula is confirmed by experiments and computer simulation. Results : Using the derived formula, the SQNRs in various main magnetic fields with various receiver systems are evaluated. Since the quantization noise is proportional to the signal amplitude, yet it cannot be reduced by simple signal averaging, it could be a serious problem in high field imaging. In many receiver systems employing analog-to-digital converters (ADC) of 16 bits/sample, the quantization noise could be a major noise source limiting overall system SNR, especially in a high field imaging. Conclusion : The field strength of MRI system keeps going higher for functional imaging and spectroscopy. In high field MRI system, signal amplitude becomes larger with more susceptibility effect and wider spectral separation. Since the quantization noise is proportional to the signal amplitude, if the conversion bits of the ADCs in the receiver system are not large enough, the increase of signal amplitude may not be fully utilized for the SNR enhancement due to the increase of the quantization noise. Evaluation of the SQNR for various systems using the formula shows that the quantization noise could be a major noise source limiting overall system SNR, especially in three dimensional imaging in a high field imaging. Oversampling and off-center sampling would be an alternative solution to reduce the quantization noise without replacement of the receiver system.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.2
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• pp.66-73
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• 2004

As one of the typical farming practices in the sloped upland in Pyeongchang and Hongcheon area, application of piling with coarse saprolite materials has been practiced by farmers for several reasons such as reduction of damage by monocropping, better development of plant roots, and better drainage. However, adverse effect on application of coarse saprolite soil materials to environmental aspects should not be ignored. Therefore, this research was conducted to evaluate the physicochemical properties of coarse saprolite materials in upland fields in Pyeongchang area. According to particle size distribution of coarse saprolite materials, averaged gravel contents for Pyeongchang and Hongcheon county were 16.7 and 25.3%, respectively. There was no significant difference in gravel contents by soil depth, and CV values for each particle size ranged from 20 to 40%, which implied that application of coarse material with similar properties. When we compared CEC values of dressed soil with or without considering gravel content, CEC values decreased as increasing gravel contents. The penetration resistances were 0.04-7.48 MPa at the 0 to 10 cm surface soil, and 0.10 to 8.80 MPa at the depth below 11 cm. The bulk density of the soil was $1.15g\;cm^{-3}$ at the surface soil and 1.29 to $1.35g\;cm^{-3}$ at the soil depth below 10 cm. The organic matter content, cation exchange capacity, and avaliable $P_2O_5$ concentrations of soil in upland where piling with saprolite materials of Pyeongchang area applied were $12.4g\;kg^{-1}$, $7.1cmol_c\;kg^{-1}$, and $526mg\;kg^{-1}$, respectively. Cation exchange capacity was lower than that of averaged Korean upland soil, while available $P_2O_5$ concentration was relatively higher than that of averaged Korean upland, which indicated high input of various fertilizers.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.4
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• pp.325-333
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• 1992

An investigation was carried out to find out the effects of long-term application (14 and 28 years) of rice straw, compost and wheat straw on changes in soil chemical and physical properities, aspests of releasing potential nitrogen and nitrogen uptake by rice and maize from fine textured paddy soils with double cropping system in warm temperate area. The result obtained were summarized as follows : 1. The long-term application of organic matters improved plow layer and soil physical properties : bulk density and solid phase were decreased, while porosity and gaseous phase were decreased. 2. Average increment of total carbon per year was 0.0371% and 0.0407% for rice straw and compost, respectively, from 1 through 14 years ; it was 0.0007% and 0.0014% for the rice straw and compost, respectively, from 15 years through 28 years. The average increment of total notrogen per year was 0.0025% and 0.038% for the rice straw and compost, respectively, from 1 through 14 years ; 0.0014% and 0.0024% for the same treatments from 15 through 28 years. 3. $NH_4-N$ and amide-N were high in the soils with wheat straw application for 28 years ; the amino sugar-N in the soils with compost application for 28 years ; amino acid -N in the soils with rice straw application for 14 and 28 years ; and unidentified-N, in the control. 4. The released amount of available nitrogen with the submerged condition was higher at $30^{\circ}C$ than at $25^{\circ}C$ during the incubation. The amount of released available nitrogen at the field was aproximately same as that of $25^{\circ}C$ incubation. However, the released amounts from the incubation and the field were always lower than those extracted with reagents. 5. The amount of nitrogen uptake by rice and maize was highly correlated with available nitrogen extracted with phosphate buffer(pH 7.0). 6. The ratio of yield increase(milled rice) was 17, 12 and 7%, respectively, by application of rice straw, compost and wheat straw for 28 years, and 11% by application of rice straw for 14 years.

• Economic and Environmental Geology
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• v.45 no.6
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• pp.661-672
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• 2012

Lab scale experiments to investigate the dissolution reaction among supercritical $CO_2$-sandstone-groundwater by using sandstones from Gyeongsang basin were performed. High pressurized cell system (100 bar and $50^{\circ}C$) was designed to create supercritical $CO_2$ in the cell, simulating the sub-surface $CO_2$ storage site. The first-order dissolution coefficient ($k_d$) of the sandstone was calculated by measuring the change of the weight of thin section or the concentration of ions dissolved in groundwater at the reaction time intervals. For 30 days of the supercritical $CO_2$-sandstone-groundwater reaction, physical properties of sandstone cores in Gyeongsang basin were measured to investigate the effect of supercritical $CO_2$ on the sandstone. The weight change of sandstone cores was also measured to calculate the dissolution coefficient and the dissolution time of 1 g per unit area (1 $cm^2$) of each sandstone was quantitatively predicted. For the experiment using thin sections, mass of $Ca^{2+}$ and $Na^+$ dissolved in groundwater increased, suggesting that plagioclase and calcite of the sandstone would be significantly dissolved when it contacts with supercritical $CO_2$ and groundwater at $CO_2$ sequestration sites. 0.66% of the original thin sec-tion mass for the sandstone were dissolved after 30 days reaction. The average porosity for C sandstones was 8.183% and it increased to 8.789% after 30 days of the reaction. The average dry density, seismic velocity, and 1-D compression strength of sandstones decreased and these results were dependent on the porosity increase by the dissolution during the reaction. By using the first-order dissolution coefficient, the average time to dissolve 1 g of B and C sandstones per unit area (1 $cm^2$) was calculated as 1,532 years and 329 years, respectively. From results, it was investigated that the physical property change of sandstones at Gyeongsang basin would rapidly occur when the supercritical $CO_2$ was injected into $CO_2$ sequestration sites.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.1
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• pp.1-12
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• 1997

As it has been reported that the depolarization induced acetylcholine (ACh) release is modulated by activation of presynaptic $A_1$ adenosine heteroreceptor and various evidence suggest that indicate the $A_2$ adenosine receptor is present in the striatum, this study was undertaken to delineate the role of adenosine receptors on the striatal ACh release. Slices from the rat striatum were equilibrated with $[^3H]$choline and then the release amount of the labelled product, $[^3H]$ACh, which was evoked by electrical stimulation (rectangular pulses, 3 Hz, 2 ms, 24 mA, $5\;Vcm^{-1}$, 2 min), was measured, and the influence of various agents on the evoked tritium outflow was investigated. And also, quantitative receptor autoradiography and drug-receptor binding assay were performed in order to confirm the presence and characteristics of $A_1$ and $A_2$ adenosine receptors in the rat striatum. Adenosine $(10{sim}100\;{mu}M)$ and $N^6$-cyclopentyladenosine (CPA, $1{sim}100\;{mu}M)$ decreased the $[^3H]$ACh release in a dose-dependent manner without changing the basal rate of release in the rat striatum. The reducing effects of ACh release by adenosine and CPA were abolished by 8-cyclopentyl-1,3-dipropy-Ixanthine (DPCPX, 2 ${mu}M$), a selective $A_1$, adenosine receptor antagonist, treatment. The effect of adenosine was potentiated markedly by 3,7-dimethyl-1-propargylxanthine (DMPX, 10 ${mu}M$), a specific $A_2$ adenosine receptor antagonist. 2-P-(2-carboxyethyl)phenethylamimo-5'-N- ethylcarboxamidoadenosine hydrochloride (CGS-21680C), in concentrations ranging from 0.01 to 10 ${mu}M$, a recently introduced potent $A_2$ adenosine receptor agonist, increased the $[^3H]$ACh release in a dose related fashion without changing the basal rate of release. These effects were completely abolished by DMPX $(10\;{mu}M)$. In autoradiograrhy experiments, $[^3H]$2-chloro-$N^6$-cyclopentyladenosine ($[^3H]$ CCPA) bindings were highly localized in the hippocampus and the cerebral cortex. Additionally, lower levels of binding were found in the striatum. However, $[^3H]$CGS-21680C bindings were highly localized in the striatal region with the greatest density of binding found in the caudate nucleus and putamen. Lower levels of binding were also found in the nucleus accumbens and olfactory tubercle. In drug-receptor binding assay, binding of $[^3H]$ CCPA to $A_1$ adenosine receptors of rat striatal membranes was inhibited by CPA ($K_i$ = 1.6 nM) and N-ethylcarboxamidoadenosine (NECA, $K_i$ = 12.9 nM), but not by CGS-21680C ($K_i$ = 2609.2 nM) and DMPX ($K_i$ = 19,386 nM). In contrast, $[^3H]$CGS-21680C binding to $A_2$ denosine receptors was inhibited by CGS-21680C ($K_i$ = 47.6 nM) and NECA ($K_i$ = 44.9 nM), but not by CPA ($K_i$ = 2099.2 nM) and DPCPX ($K_i$ = 19,207 nM). The results presented here suggest that both types of $A_1$ and $A_2$ adenosine heteroreceptors exist and play an important role in ACh release in the rat striatal cholinergic neurons.

• Journal of Animal Science and Technology
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• v.45 no.2
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• pp.199-210
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• 2003

The effect of feeding a cyclic oligosaccharide, $\beta$-cyclodextrin($\beta$CD) on plasma cholesterol and triacylglyceride concentrations and on antithrombotic activity were investigated in rats fed a control chow diet, or one either high in cholesterol or in saturated fat. The bleeding time of $\beta$CD-fed groups was significantly prolonged by 293%, 157% and 218% in normal, high cholesterol and high fat diet fed groups, respectively, as compared to the control group(p<0.05). The whole blood clotting time was significantly increased by 202%, 168% and 211% in normal, high cholesterol and high fat diet fed groups as compared to control group, respectively(p<0.05). The $\beta$CD diet caused a marked decrease in plasma total lipid(TL), triacylglyceride(TAG), total cholesterol (TC) and low density lipoprotein- cholesterol (LDL-C) concentrations. The plasma TL concentration was significantly decreased by 70%, 82% and 87% in normal, high cholesterol and high fat diet fed groups as compared to the control group, respectively(p<0.05). The plasma TAG concentration was significantly decreased by 89%, 43% and 59% in normal, high cholesterol and high fat diet fed groups, respectively, as compared to the control group(p<0.05). The plasma TC concentration was significantly decreased by 28%, 62% and 36% in normal, high cholesterol and high fat diet fed groups, respectively, as compared to the control group(p<0.05). The LDL-C concentration was significantly decreased by 39%, 54% and 25% in normal, high cholesterol and high fat diet fed groups as compared to control group, respectively(p<0.05). The plasma total bile acids contents of $\beta$CD group was significantly increased by 66%, 95% and 97% in normal, high cholesterol and high fat diet fed groups as compared to control group, respectively(p<0.05). The hepatic HMG-CoA reductase activity was significantly lowered by 41% in the $\beta$CD-fed group compared to normal diet fed rats(p<0.05). The fecal steroid excretions of the $\beta$CD groups was significantly increased by 167% in normal diet fed rats(p<0.05). These results suggest that the $\beta$CD has a biological active function on antithrombotic activity and is hypolipidemic, hypotriglyceridemic and hypocholesterolimic agents. These are all effects that can help to prevent obesity and coronary heart disease in humans.

• The Journal of Korean Society for Radiation Therapy
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• v.19 no.2
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• pp.83-90
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• 2007

Purpose: In this study, it was investigated whether commercially produced beer is able to prevent a lymphocyte from radiation induced apoptosis. Materials and Methods: Whole blood samples were acquired from 5 healthy volunteers (male, 26$\sim$38 years old) and the lymphocyte were isolated by density gradient centrifugation. Radiation induced apoptosis of the lymphocyte were investigated by 0.5 Gy, 1.0 Gy, 2.0 Gy, 3.0 Gy to 5.0 Gy irradiation. In some experiments, the donor drunk beer and then blood samples were collected. In other experiments, melatonin or glycine betain was added to lymphocyte culture medium. Treated or untreated lymphocytes were cultured for 60 hours and radiation induced apoptosis of the lymphocyte was analyzed by annexin-V staining through flow cytometery. Results: Relative radiation induced apoptosis ratio of the untreated lymphocytes is 1.22$\pm$1.1, 1.22$\pm$1.1, 1.38$\pm$1.0, 1.47$\pm$1.1, 1.50$\pm$1.2 by radiation dose of 0.5 Gy, 1.0 Gy, 2.0 Gy, 3.0 Gy and 5.0 Gy respectively. Relative radiation induced apoptosis ratio of lymphocytes is isolated from beer drunken donors is 0.97$\pm$1.0, 0.99$\pm$1.0, 1.11$\pm$0.9, 1.29$\pm$1.1, 1.15$\pm$1.1 by radiation doses respectively which are reduced 21.5% compared with untreated lymphocyte. Relative radiation induced apoptosis ratio of the lymphocytes is isolated from non-alcohol beer drunken donors is 1.22$\pm$1.1, 1.17$\pm$1.1, 1.13$\pm$1.3, 1.38$\pm$1.2, 1.32$\pm$1.1 by radiation dose of 0.5 Gy, 1.0 Gy, 2.0 Gy, 3.0 Gy and 5.0 Gy respectively which are reduced 10.8% compared with the untreated lymphocyte. Conclusion: As a result, it is suggested that beer may protect the lymphocyte from radiation damage and inhibit apoptosis.