• YAKHAK HOEJI
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• v.58 no.5
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• pp.287-293
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• 2014

Alzheimer's disease (AD), most common form of dementia is characterized that memory deficit and loss of cognitive function. This study was evaluated cognitive enhancing effect of water and ethanol extracts of Codonopsis lanceolata and compared using Morris water maze and passive avoidance test. The water and 70% ethanol extracts (100, 300 and 500 mg/kg) were administered to mice. The neuroprotective effect on glutamate-induced cell death in HT22 cells was additionally investigated using MTT assay. Results showed 70% ethanol extract of Codonopsis lanceolata enhanced cognitive function than water extract, as shown by decrease in escape latency time in Morris water maze test. In passive avoidance test, 70% ethanol extract also increased the latency time compared to the water extract. Furthermore, 70% ethanol extract significantly protected neuronal cell against glutamate cytotoxicity and showed higher than neuroprotective effect of water extract. These results indicate that 70% ethanol extract more improve spatial cognitive ability and protected neuronal cells than water extract.

• Journal of Sericultural and Entomological Science
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• v.40 no.1
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• pp.17-22
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• 1998

To investigate the detoxificative effect of tea, five kinds of tea(mulberry, anaerobic treated mulberry, green, barly tea and corm tea) were selected and determined their dotoxication activities for Cd and Pb in drinking water. The effect of tea on the removal of Cd and Pb were increased proportionally to the contents of teas. Anaerobic treated mulberry leaf tea showed stronger detoxication activity than the others. In drinking water contaminated with Cd, the removal effect of Cd was high 27% by anaerobic treated mulberry leaf tea and 14% by mulberry leaf tea as compared to green tea. Also, in drinking water with Pb, the removal effect of anaerobic treated mulberry leaf tea was the best among five kinds of tea. Pretreatment method on the removal effect of Cd was better than post-treatment method in the treatment method.

• Transactions of the Korean Society of Automotive Engineers
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• v.1 no.1
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• pp.14-21
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• 1993

The effect of coolant flow pattern on the metal temperature of the combustion chamber was studied in 1.5L and 1.8L gasoline engines. One of the main important points in the design of the water jacket is the increase of the coolant flow velocity. In this paper, the water jackets of the cylinder head and the cylinder block were visualized for the purpose of improving the coolant flow pattern. By the use of this technique, the optimal design of the size and th location of the water transfer fole was possible. And, to lower the metal temperatures of the thermally critical parts, the drilled water passages were employed. To investigate of effect of the improved flow pattern and the drilled water passages, the metal temperatures of the combustion chamber were measured. As a result of the temperature measurement, it was found out that both the change of flow pattern and the drilled water passages have significant effect on the reduction of the peak metal temperature.

• Geomechanics and Engineering
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• v.32 no.4
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• pp.445-452
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• 2023

Temperature is one of the important factors affecting the permeability of water in the soil. In the present study, the impact of water temperature on hydraulic conductivity (k) with and without coarse aggregations by considering six types of soils was analyzed. Moreover, the effect of sand and gravel presence in the soil was investigated through the infiltration based on constant and inconstant water head experiments. Results indicated that by increasing the water temperature, adding gravel to sandy soil caused the hydraulic conductivity to raise. It is supposed that the gravel decreased the contact surface between the water and the soil aggregates. It is deduced that due to decreasing kinetic energy, k tends to have lower values. Furthermore, adding the sand to sandy silt-clay soil showed that the sand did not have a marginal effect on the variation of k since the added sand cannot increase the contact surface like gravel. Finally, increasing the main diameter of the soil will increase the effect of the water temperature on hydraulic conductivity.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.5
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• pp.773-777
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• 2012

Recently UV laser micromachining processes is widely introduced to meet the needs of advanced components of IT, BT and ET industries. Due to the characteristics of non-contact and high-speed laser processing, UV laser micromachining is applied to manufacture very thin substrate such as polymer, metals and composite. These minimum line width obtained by UV laser micromachining is generally determined from laser wavelength, optical lens and its numerical aperture. In this paper we will show the lens effect of water droplet on the surface of workpiece to reduce the line width when UV laser light is irradiated and focused through the water droplet. Because of the refraction effect generated by the semi-spherical or spherical shape of water droplet, we can find smaller line width. And water droplet could not only protect thermal deformation, but also carry away burr around micro dent. Firstly fundamental theory of minimum line width was derived from relationship between the geometry of water droplet and laser light trace, and then experimental and simulation results will be finally compared to verify the effectiveness of water droplet lens effect of UV laser micromachining process.

• Tribology and Lubricants
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• v.33 no.6
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• pp.245-250
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• 2017

In this work, we examine pure water and water with nanoparticles to investigate water lubrication characteristics and the effect of nanoparticles as lubricant additives for different substrates. We test carbon-based coatings and metals such as high-speed steel and stainless steel in pure deionized (DI) water and DI water with nanoparticles. We investigate water lubrication characteristics and the effect of nanoparticles based on the friction coefficient and wear rate for different substrates. The investigation reveals that nanoparticles enhance the friction and wear properties of high-speed steel and stainless steel. The friction coefficient and wear rate of both high-speed steel and stainless steel decreases in DI water with nanoparticles compared with the results in pure DI water. The presence of nanoparticles in water show good lubricating effect at the contact area for both high-speed steel and stainless steel. However, for carbon-based coatings, nanoparticles do not improve friction and wear properties. Rather, the friction coefficient and wear rate increases with an increase in the concentration of nanoparticles in case of water lubrication. Because carbon-based coatings already have good tribological properties in a water environment, nanoparticles in water do not contribute toward improving the friction and wear properties of carbon-based coatings.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.6
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• pp.951-955
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• 1999

The effects of restricting feed [60% of ad libitum (AL) intake] (FR) or water provided from 0900 h to 1600 h, daily) (WR) or both (FWR) from 14 to 42 days of age on heterophil/lymphocyte (H/L) response and performance in broiler chickens under the hot humid tropical conditions were determined. Feed and/or water limitation retarded growth, but had no adverse effect on overall feed conversion ratio and survivability. The trend for total feed and water consumption was similar to body weight pattern with AL>WR>FR>FWR. The nutritional regimens had significant effect on overall water:feed ratios with FR>(AL=WR)>FWR. Restriction of feed and/or water resulted in marked elevation of H/L ratios. As measured by H/L ratios, the effect of adapting to FR dissipated between 16 to 21 days after the onset of feed restriction. The H/L ratios of WR and FWR birds remained elevated throughout the duration of the experiment.

• Korean Journal of Poultry Science
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• v.21 no.2
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• pp.93-99
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• 1994

Chickens subjected to heat stress decrease their heat production by consuming less feed. The lowered feed intake naturally brings about decreased production performance of chicken. The only exception to this is the increased survivability. Birds drink less when they eat less. In hot enviror-mental temperature, chicken need more water for increased heat loss through evaporation an increased urine excretion. Thus, the increased water intake may alleviate the heat stress of chicken. Various electrolytes supplementation to feed or drinking water can alleviate the heat stress of chicken by their effect of increasing water intake. Lasalocid, an ionophorous coccidiostat, was found to have the effect of increasing water consumption of chicken, thereby improving the lowered production performance of heat-stressed chicken. Finally, dietary fiber could be another possible element which can exert beneficial effects on heat-stressed chicken.

• Korean Membrane Journal
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• v.11 no.1
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• pp.21-28
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• 2009

We investigated the effect of organic materials on membrane fouling in advanced drinking water treatment by a hybrid module packed with granular activated carbon (GAC) outside multi-channel ceramic microfiltration membrane. Synthetic water was prepared with humic acid and kaolin to simulate natural water resouces consisting of natural organic matter and inorganic particles. Kaolin concentration was fixed at 30 mg/L and humic acid was changed as 2~10 mg/L to inspect the effect of organic matters. Periodic back-flushing using permeate water was performed for 10 sec per filtration of 10 min. As a result, both resistance of membrane fouling (Rf) and permeate flux (J) were influenced highly by concentration of humic acid. It proved that NOM like humic acid could be an important factor on membrane fouling in drinking water treatment. Turbidity and UV254 absorbance were removed up to above 97.4% and 59.2% respectively.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.4
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• pp.209-214
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• 2009

The purpose of this study is to investigate the effect exchanging water supply on the' rainwater in detached house. It is difficult to decide water supply amount for a closet in detached house, Therefore, to obtain water supply for closet in detached house, it used regression equation using 1,569 data of frequency of used closet and during 120 days. In detached house, the frequency of used closet is 14.6 times/day and water supply amount is $219 {\ell}/day$. The optimum rainwater tank size which is decided by regression equation and using weather data is $8.5\;m^3$. The effect exchanging water supply on the rainwater in detached house is up 50%.