• The Korean Journal of Physiology
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• v.21 no.2
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• pp.297-304
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• 1987

A study was carried out to find out the relationship between arginine vasopressin (AVP) release and plasma osmolality in 15 young men (age: 21.4 yr). After an overnight fasting, wale. (20 ml/kg) was imbibed, and venous blood and urine samples were collected every 30 min for 90 min. then 5% saline was infused (0.06 ml/min/kg) for 120 min. AVP was extracted on Sep-Pak column and measured by radioimmunoassay. Under basal condition, plasma osmolality (pOsm), AVP (pAVP) and aldosterone (pAldo) levels were 286.5 mOsm/kg, 1.1 pg/ml, and 140 pg/ml, respectively. pAVP became undetectable during maximum water diuresis, and increased in response to hypertonic saline infusion. pAVP level began to increase when pOsm was above 280 mOsm/kg. Changes in urinary AVP excretion (uAVP) was parallel to pAVP levels. The fall in pAVP was followed by a decrease in uAVP, uOsm and an increase in free water clearance, while the later rise in pAVP was followed by an increase in uAVP, uOsm and a decrease in free water clearance. When pooling all data together, relationships between pAVP and pOsm, and uAVP and uOsm were best expressed by an exponential relationship (r=0.78, 0.86, respectively). pAldo level decreased to 71 pg/ml after water ingestion, and decreased further to 30 pg/ml 2 hr after 5% saline infusion. Even at the same pNa, pAldo level during dehydration state was significantly higher than during hydration state. Negative exponential relation (r=-0.59) was observed between pAldo and pNa. Response to change in body fluid volume was greater in aldosterone than in AVP release.

• Journal of Wetlands Research
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• v.18 no.1
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• pp.100-112
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• 2016

In recent, the direction of water resources policy is changing from the typical plan for water use and flood control to the sustainable water resources management to improve the quality of life. This change makes the information related to water resources such as data collection, management, and supply is becoming an important concern for decision making of water resources policy. We had analyzed the structured data according to the purpose of providing information on water resources. However, the recent trend is big data and cloud computing which can create new values by linking unstructured data with structured data. Therefore, the trend for the management of water resources information is also changing. According to the paradigm change of information management, this study tried to suggest an application of big data and cloud computing in water resources field for efficient management and use of water. We examined the current state and direction of policy related to water resources information in Korea and an other country. Then we connected volume, velocity and variety which are the three basic components of big data with veracity and value which are additionally mentioned recently. And we discussed the rapid and flexible countermeasures about changes of consumer and increasing big data related to water resources via cloud computing. In the future, the management of water resources information should go to the direction which can enhance the value(Value) of water resources information by big data and cloud computing based on the amount of data(Volume), the speed of data processing(Velocity), the number of types of data(Variety). Also it should enhance the value(Value) of water resources information by the fusion of water and other areas and by the production of accurate information(Veracity) required for water management and prevention of disaster and for protection of life and property.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.8
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• pp.661-666
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• 2003

Constant area expansion devices such as capillary tubes, short tube orifices are being gradually replaced with electronic expansion valves (EEVs) because of increasing focus on comfort and energy conservation. In this study, the performance of a water-to-water heat pump as a function of refrigerant charge is investigated in steady state, cooling mode operation with expansion devices of a capillary tube and an EEV. The performance of the capillary tube system varies drastically according to the change of refrigerant charge amount and inlet temperature of the secondary fluid in the condenser. Cooling capacity and COP of the EEV system show little dependence on the refrigerant charge, while those are strongly dependent on the secondary fluid temperature at the condenser inlet. In general, for a wide range of operating conditions the EEV system shows much higher performance as compared with the capillary tube system. The performance of the EEV system can be optimized by adjusting EEV opening to maintain a constant superheat at all test conditions.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.225.2-226
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• 2003

The prolonged mechanical grinding process may enhance the bioavailability of the drugs due to the change of solid state such as micronization and decrease of crystallinity. A series of attempts to enhance the bioavailability of insoluble drugs have been made by the fine grinding technique using a planetary mill. The objective of the present study is to investigate the possibility of improving the dissolution properties of poorly water- soluble drugs such as diphenyl hydrantoin (phenytoin) and diphenyl dimethyl dicarboxylate (DDB) based on the molecular interaction between drug and additives during pharmaceutical processing to be related with the bioavailability behavior. (omitted)

• Journal of Korean Society on Water Environment
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• v.29 no.2
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• pp.176-183
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• 2013

The variation of the stable region of arsenic compounds in aqueous environment with temperature has been investigated by constructing the Pourbaix diagram of arsenic at different temperatures. The standard potential corresponding to the boundary between arsenic compounds with different charge valence was estimated to be decreased with temperature, which means the stability of arsenic compound with +5 charge valence increases. The distribution diagram of the most highly oxidized arsenic compound showed that arsenic acid is formed at higher pH and arsenate is generated at lower pH as temperature rises. The aquatic toxicity due to arsenic compounds was considered to be decreased with temperature in the neutral pH condition based on the $LD_T$ value defined in this study.

• Bulletin of the Korean Chemical Society
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• v.20 no.12
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• pp.1451-1456
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• 1999

Solvolyses of α-methoxy-α-(trifluoromethyl)phenylacetyl chloride in H₂O, D₂O, CH₃OD, 50% D₂O-CH₃OD, and in aqueous binary mixtures of acetone, dioxane, ethanol and methanol are investigated at 25.0℃. The Grunwald-Winstein plots of first-order rate constants for α-methoxy- α-(trifluoromethyl)phenylacetyl chloride with $Y_{Cl}$ show a dispersion phenomenon. Solvent nucleophilicity N has been shown to give considerable im-provement when it is added as an 1N term to the original Grunwald-Winstein for the solvolyses of α-methoxy- α-(trifluoromethyl)phenylacetyl chloride. The dispersions in the Grunwald-Winstein correlations in the present studies are caused by solvent nucleophilicity. The magnitude of l and m values associated with a change of solvent composition predicts the associative $S_N2$ transition state. The kinetic solvent isotope effects determined in deuterated water and methanol are consistent with the proposed mechanism of the general base catalyzed associative $S_N2$ or $S_AN$ mechanism for the of α-methoxy- α-(trifluoromethyl)phenylacetyl chloride.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.1 no.1
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• pp.9-20
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• 1989

This paper presents an analysis to predict thermal behaviors of water in ice storage tank during the coldness release process. To deal with complicated transient phenomena due to ice-water phase change and the density inversion, a theoretical model which consists of initial perfectly mixed, stratified and thermal diffusion state was introduced and a criterion on the growth of thermal boundary layer was developed. The analysis includes considerations on the type of ice-making heat exchanger, refrigerator on/off and tank arrangement. Also, discussions on the various parameters and operating conditions which have influence on the performance of the system were made. Finally, simulated results were shown, which agreed with experiments in trends reasonably.

• Proceedings of the Korea Water Resources Association Conference
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• 1993.07a
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• pp.3-26
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• 1993

I have briefly described some of the important advances in hydrosystems and to remark on the important scientific research priorities in hydrological sciences. We have concentrated on data collection systems, real-time control of hydrosystems, global climate change and decision support systems and GIS. In summary, I would like to stress the following points: - the advances in data collection systems, advanced methodologies for interfacion hydrologic, hydraulic, and optimization models through optimal control approaches; and the advances in decision support systems and GIS will allow the interfacing of all these technologies into some sophisticated and much needed tools for operating hydrosystems; - the ability to better understand the hydrologic processes and their relationships to other earth processes is important to understanding and modelling of the hydrologic cycle and its interactions with the ocean-atmosphere system; - and the solution to a better understanding of hydrologic sciences needs to be an international effort such as the GEWEX program briefly discussed above. I would like to thamk each of you for listening to my lecture and to once again thank those responsible for me being here today. Thank you.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1170-1180
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• 2009

Recently this country has carried out the coast reclamation centering on the west and south coast for effective practical use of a country, considering purchase of materials and environmental problem, most reclaiming work is processing to spoil reclamation which is easy to secure the amount of materials. In case of weak ground that is formed by spoil reclamation like this, initial moisture content is high, as slurry state that is rarely revealed ground strength, compressibility and water permeability have been shown nonlinear change by compaction progress. Analysis of weak ground is unreasonable because the existing Terzaghi compaction theory analyzes compaction fixed number to regular invariable number for prediction of compaction state. This study computes the relation with void ratio-effective pressure and void ratio-finite transformation which is the most basic matter to predict finite strain compaction state of the south coast spoil, and analyze the basic feature to predict compaction feature of the south coast spoil reclaimed ground.

• Journal of Pharmaceutical Investigation
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• v.9 no.3
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• pp.22-26
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• 1979

This report was carried out toxicity test for the mosquito coil made of Ginseng leaf and the residue after extraction of Ginseng root. This results are as follows: In the first group, was not shown any special difference on the body weight, the motion and dissection. In the second group, was not shown any Special difference on the body weight, considerable difference on the motion and considerable loss of appetite besides very slight loss, but came cack soon again to normal state by change of air after a moment. In the third group, the body weight and appetite was depressed very slightly and the motion was shown very slightly difference, but came back soon again to normal state by chenge of air after a moment too. No one was died, and all the animal were the normal state on the reslt of dessection, Therefore, we have positive evidence that this mosquito coil powder is applied to animals without any toxicity.