• Journal of Biosystems Engineering
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• v.5 no.2
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• pp.26-39
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• 1980

A study was investigated to find out the mechanical optimum conditions of power tiller-plow system on both paddy field and upland. Mathematical model was developed for the theoretical analysis of this system and the experimentation on the field was carried out with two different sizes of 5PS and 8PS power tiller equipped with rubber tire. 1) The relationship between the plowing depth and draft resistance of the power tiller-plow system was a quadratic function. 2) The minimum point of the specific draft resistance of the 5 PS plow was found at the smaller plowing depth than that of 8 PS plow, therefore we can find that the curved surface of 5PS plow bottom should be improved for the effective plowing operation. 3) As the improvement of the mechanical balance by the desirable change of the curved surface of plow bottom, the relative position of hitch point and dimension of plow beam would be realized, the 5 PS power tiller could be used to plow deeply (about 16-17cm). 4) The virtual acting point of the total draft resistance on the plow bottom approached to the land side as the plowing depth increased. 5) The resultant of vertical reaction force $R_2$ on the landside was increased with the plowing depth, while the vertical reaction force $R_1$ on the wheel was decreased as the slope angle of the body of power tiller increased. 6) For the effective plowing operations ; a) The slope angle of the body should be as small as possible. b) The diameter of the wheel should be as small possible. c) The horizontal and vertical distances $l_2, h_1$ between the wheel axis and plow bottom should be as large as possible. 7) To use the 5PS power tiller as the major unit of agricultural machinery, the curved surface of the 5 PS plower bottom and the mechanism of attachment between the power tiller and the plow should be changed as the indications of this study, and in addition to these, the new operation method of the field work should be developed.

• Journal of Nutrition and Health
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• v.30 no.1
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• pp.40-47
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• 1997

Dietary peptides have recently received attention regarding their beneficial effects on nutrient metabolism since the caseinphosphoptides obtained from casein hydrolysate are generally believed to enhance the intestinal absorption of Ca. The two experiments were conducted to investigate the effects of various hydrolyzed fractions of gluten on Ca bioavailability. The gluten hydrolysate of dietary components was produced by enzymatic hydrolysis of gluten whereas gluten hydrolysate supernationt and its precipiate resulted from centrifugation. In experiment I, the rats were for 4 weeks fed the 4 kinds of diets containing same amount of nitrogen and calories and diffeing only in the forms of nitrogen sources. The diets were gluten (G), gluten hydrolysat(GH), gluten hydrolysate supernatant(GHS) and gluten hydrolysate precipitatie(GHP). Determination was made for the body weight gain, serum Ca concentration, Ca solubility in small intestinal contents, bone weight, length and stength, bone ash and Ca content, and Ca balance, respectively. No significant difference was noticed as regards growth, serum Ca, and bone dimension and Ca content among rat groups. More significant increase was observed with regard to Ca absorption and intestinal solubility in the rats receiving the GH or GHS diet which containe crude gluten peptides, than in those subjected to G or GHP diet. In experiment II, in vitro determination for Ca solubility was made to ascertain the mechanism responsible for the effects of gluten peptides on Ca absorption. The 10mM Ca in potassium phosphate buffer solution(pH 7.0) incubated for 3 hours at 37$^{\circ}C$ by the GHS fraction, was observed to be capable of increasing the Ca solubility at 5-25mg/ml concentration of gluten peptides. These observations suggest that the gluten peptides from gluten hydrolysate may enhance the Ca absorption efficiency by increasing the solubility of Ca in small intestine.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.3C
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• pp.102-111
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• 2005

In this paper, we propose an advanced hardware architecture for the fast inter prediction engine of the video coding standard MPEG-4 AVC. We describe the algorithm and derive the hardware architecture emphasizing and real time operation of the quarter_pel based motion estimation. The fast inter prediction engine is composed of block segmentation, motion estimation, motion compensation, and the fast quarter_pel calculator. The proposed architecture has been verified by ARM-interfaced emulation board using Excalibur & Virtex2 FPGA, and also by synthesis on Samsung 0.18 um CMOS technology. The synthesis result shows that the proposed hardware can operate at 62.5MHz. In this case, it can process about 88 QCIF video frames per second. The hardware is being used as a core module when implementing a complete MPEG-4 AVC video encoder chip for real-time multimedia application.

• The Journal of Korean Medicine
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• v.39 no.3
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• pp.1-16
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• 2018

Objectives: The purpose of this study was to investigate the effects of 56 herbal formulae covered by the National Health Insurance Corporation (NHIC) on dementia-related biomarkers and neuronal cell changes. Methods: The 56 herbal formulae were extracted with 70% ethanol at $100^{\circ}C$ for 2 h. The antioxidant properties was measured by radical scavenging assay using ABTS+ radical. The acetylcholinesterase (AChE) activity was tested by Ellman's assay and $amyloid-{\beta}$ ($A{\beta}$) aggregation was determined using fluorescence method. To estimate the inhibitory effects of herbal formulae on neuronal cell death and inflammation using HT22 hippocampal cells and BV-2 microglia, respectively. Results: Among the 56 herbal formulae, Dangguiyukhwangtang, Banhasasimtang, Samhwangsasimtang, Cheongwiesan, Hwangryunhaedoktang, Banhabaekchulchunmatang, Jaeumganghwatang, Cheongseoikgitang, and Hoechunyanggyuksan has a significant inhibitory effects on acetylcholinesterase (AChE) activity. Doinseunggitang and Samhwangsasimtang exerted the effect on the inhibition of $amyloid-{\beta}$ ($A{\beta}$) aggregation. Additionally, 10 herbal formulae affected AChE and $A{\beta}$ aggregation revealed antioxidant activity as well as neuroprotective and anti-neuroinflammation effects in neuronal cell lines. Conclusions: 10 herbal formulae that have been shown to be effective against the major dementia markers have been shown to have antioxidant activity, neuronal cell protection and inhibition of brain inflammation. Further investigation of these herbal formulae will need to be validated in dementia animal models.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.1
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• pp.107-116
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• 2006

The main purpose of this study is to develop the greenhouse gas emission factor for power plant using bituminous coal. The power plant is a major source of greenhouse gases among the sectors of fossil fuel combustion, thus information of its emission factors is very essential to the establishment of control strategies for the greenhouse gas emissions. These emission factors derived in this study were compared with those of U. S. EPA, AGO and CCL. The $CO_{2}$ concentrations in the flue gas were measured using NDIR analyser and the GC-FID with a methanizer. The amount of carbon (C) and hydrogen (H) in fuel was measured using an elemental analyzer. Calorific values of fuel were also measured using a calorimeter. Caloric value of bituminous coal used in the power plants were 5,957 (as received basis), 6,591 (air-dried basis) and 6,960 kcal/kg (dry basis). Our estimates of carbon emission factors were lower than those of IPCC. The CO2 emission factors for the power plants using bituminous coal were estimated to be 0.791 Mg/MWh (by carbon contents and caloric value of the fuel) and 0.771 Mg/MWh (by $CO_{2}$ concentration of the flue gas). The $CO_{2}$ emission factors estimated in this study were $3.4\sim 5.4\%$ and $4.4\sim 6.7\%$ lower than those of CCL (2003) and U. S. EPA (2002).

• Biomedical Science Letters
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• v.8 no.3
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• pp.179-184
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• 2002

We investigated the morphological changes and TUNEL reaction of apoptotic cells in the liver of D-galactosamine (20 mg/mouse) and lipopolysaccharide (5 $\mu\textrm{g}$/mouse)-treated 30 mice (BALB/c), and in additioa also of apoptotic cells in kidney and spleen. The livers and other some organs of mice at 6, 12, 24, 48 and 72 hrs after treatment were collected and were fixed with 10% neutral formalin and paraffin sections were stained with hematoxylin-eosin or terminal deoxynucleotidly transferase-mediated dUTP nick end labeling (TUNEL) method. Morphological changes in apoptotic hepatocytes were chondensation of nuclei and density of cytoplasms, then the margination and pyknosis of chromatin, the formation of half-moon- or horse-shoe- or ship-like shapes of condensed chromatin mass, lastly formation of apoptotic bodies, disappearance of nuclear envelopes, decrease of stainability, then lysis and disappearance of apoptotic bodies. TUNEL positive reactions of hepatocytes were appeared first moderate in uncondensed hepatocytes, severe in condensed hepatocytes, moderate in chromatin-marginated hepatocytes. These reactions also were appeared moderate in hepatocytes with half-moon- or horse-shoe- or ship-like pyknotic chromatin mass or apoptotic bodies, and mild or negative in hepatocytes with lysed apoptotic bodies or with disappeared nuclear envelopes. Consequently these results suggested that TUNEL positive reactions of hepatocytes appeared at more early stages than appearance of chromatin condensation and disappeared at more early stage than disappearance of histological findings of apoptosis. We also confirmed that the differentiation of apoptotic cells from normal healthy cells of Kupffer cells and vascular endothelial cells in liver, reticular cells and lymphocytes in spleen and epithelial cells of tubules and ducts in kidney was impossible in H-E preparations but was possible in TUNEL preparations.

• Journal of computational fluids engineering
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• v.3 no.1
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• pp.82-88
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• 1998

As a par of a project related to the development of the design algorithm of a compact heat exchanger for the application of the electronic home appliances, the effect of the discreteness of the airflow boundary generated on the cooling fin surface on the heat transfer and pressure drop characteristics of the heat exchanger was studied numerically. In general, there are two critical design parameters seriously considered in the design of the heat exchanger; heat transfer rate(Q) and pressure drop coefficient(C/sub p/). Even though the higher heat transfer rate with lower pressure drop characteristics is required in a design of the heat exchanger, it is not an easy job to satisfy both conditions at the same time because these two parameters are phenomenally inversely proportional. To control the boundary layer thickness and its length along the streamline, the surface of the flat fin was modified to accelerate the heat transfer rate on the fin surface. To understand the effect of the discreted fin size(S/sub w/) and its location(S/sub h/) on the performance of the heat exchanger in the airflow field, the flat fin was modified as shown in Fig. 1. From this study, it was found that the smaller and more number of slits on the fin surface showed the higher energy diffusion rate. It means that the discreteness of the boundary layer is quite important on the heat transfer rate of the heat exchanger. On the other hand, if the fin surface configuration is very complex than needed, higher static pressure drop occurs than required in a system and it may be a reason of the induced aerodynamic noise in the heat exchanger.

• Biomolecules & Therapeutics
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• v.21 no.5
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• pp.371-380
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• 2013

Doxorubicin is still main drug in chemotherapy with limitation of use due to adverse drug reaction. Increased oxidative stress and alteration of nitric oxide control have been involved in cardiotoxicity of doxorubicin (DOX). A Disintegrin And Metalloproteinase (ADAMs) are transmembrane ectoproteases to regulate cell-cell and cell-matrix interactions, but role in cardiac disease is unclear. The aim of this study was to determine whether DOX activates peroxynitrite and ADAM 10 and thus ADAM and matrix metalloproteinase (MMP) induce cardiac remodeling in DOX-induced cardiomyopathy. Adult male Sprague-Dawley rats were subjected to cardiomyopathy by DOX (6 times of 2.5 mg/kg DOX over 2-weeks), and were randomized as four groups. Then followed by 3, 5, 7, and 14 days after cessation of DOX injection. DOX-injected animals significantly decreased left ventricular fractional shortening compared with control by M-mode echocardiography. The expressions of cardiac nitrotyrosine by immunohistochemistry were significant increased, and persisted for 2 weeks following the last injection. The expression of eNOS was increased by 1.9 times (p<0.05), and iNOS was marked increased in DOX-heart compared with control (p<0.001). Compared to control rats, cardiac ADAM10- and MMP 9- protein expressions increased by 20 times, and active/total MMP 9 proteolytic activity showed increase tendency at day 14 after cessation of DOX injection (n=10, each group). DOX-treated $H_9C_2$ cell showed increased ADAM10 protein expression with dose-dependency (p<0.01) and morphometric changes showed the increase of ventricular interstitial, nonvascular collagen deposition. These data suggest that activation of cardiac peroxynitrite with increased iNOS expression and ADAM 10-dependent MMP 9 expression may be a molecular mechanism that contributes to left ventricular remodeling in DOXinduced cardiomyopathy.

• Plant Biotechnology Reports
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• v.4 no.3
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• pp.213-222
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• 2010

Within their natural habitat, crops are often subjected to drought and heat stress, which suppress crop growth and decrease crop production. Causing overaccumulation of glycinebetaine (GB) has been used to enhance the crop yield under stress. Here, we investigated the response of wheat (Triticum aestivum L.) photosynthesis to drought, heat stress and their combination with a transgenic wheat line (T6) overaccumulating GB and its wild-type (WT) Shi4185. Drought stress (DS) was imposed by controlling irrigation until the relative water content (RWC) of the flag leaves decreased to between 78 and 82%. Heat stress (HS) was applied by exposing wheat plants to $40^{\circ}C$ for 4 h. A combination of drought and heat stress was applied by subjecting the drought-stressed plants to a heat stress as above. The results indicated that all stresses decreased photosynthesis, but the combination of drought and heat stress exacerbated the negative effects on photosynthesis more than exposure to drought or heat stress alone. Drought stress decreased the transpiration rate (Tr), stomatal conductance (Gs) and intercellular $CO_2$ concentration (Ci), while heat stress increased all of these; the deprivation of water was greater under drought stress than heat stress, but heat stress decreased the antioxidant enzyme activity to a greater extent. Overaccumulated GB could alleviate the decrease of photosynthesis caused by all stresses tested. These suggest that GB induces an increase of osmotic adjustments for drought tolerance, while its improvement of the antioxidative defense system including antioxidative enzymes and antioxidants may be more important for heat tolerance.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.451-454
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• 2009

Production and application of biodiesel are expected to grow steadily in the coming years and thus output of its by-product, crude glycerin, will accordingly increase as well. In the present study, gasification of biodiesel by-product as a renewable energy was performed in an entrained flow gasifier to investigate the gasification performance with the operating conditions. Crude glycerin shows a high heating value of 6,000 kcal/kg and low ash and sulphur content. Gasification was conducted in a temperature range of $950\;{\sim}\;1500\;^{\circ}C$. The variation of syngas composition with excess air ratio of 0.17 ~ 0.7 for air or oxygen as a gasification agent was investigated. From the results, syngas heating value, carbon conversion and cold gas efficiency of more than $2500\;kcal/Nm^3$, 95% and 65% were achieved, respectively. The temperature dependency of syngas composition, carbon conversion, and cold gas efficiency shows a similar tendency to excess air ratio at the temperature corresponding to the excess air ratio. The $H_2/CO$ ratio of the product gas was varied from 1.25 to 0.7 with the excess air ratio and this gas composition was favorable for DME synthesis. The optimum excess air ratio for gasification of biodiesel by-product was evaluated to be an approximately 0.35 to 0.4. The present results indicate that crude glycerin can be utilized as a feedstock for gasification to make syngas.