• Journal of Biosystems Engineering
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• v.27 no.4
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• pp.327-334
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• 2002

In this study, energy conversion from thermal energy to mechanical power by using n-pentane was tested and exergy variation, cycle number, water quantity pumped and thermal efficiency were analyzed. The energy conversion was done and the water head could be ten meters on the experimental conditions. The operating temperature range of cycle was recommended to be around the liquid-vapour saturation temperature of the working fluid on the viewpoint of the maximum work. The cycle diagram was analyzed by the exergy analysis. For the constant water head, the cycle number was decreased and the water quantity per day was increased and thermal efficiency become higher when the water quantity per cycle become increasing. For the constant pumping water quantity per cycle, cycle number and the water quantity per day was decreased and the thermal efficiency become higher because the saturation temperature become higher when the water head become higher.

• KIEAE Journal
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• v.7 no.2
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• pp.25-30
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• 2007

The purpose of this research is to analyze the water quantity of the rainwater detention system based on the Planning Simulation in Residential Areas. The contents of this research consists of two main parts. The first part is to calculate the supply water quantity of the rainwater detention system and the demand water quantity of the Wonheungs' ecological park. The second part is to analyze the difference between demand and supply of water quantity, based on the Planning Simulation, in the rainwater detention system. This research will contribute to the establishment of the environment-friendly site planning methods which increase the quality of residential environment in apartment housing.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.6
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• pp.715-723
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• 2004

The quantity of residuals generated from water treatment plants depends upon the raw water quality, dosage of chemicals used, performance of the treatment process, method of sludge removal, efficiency of sedimentation, and backwashing frequency. Sludge production by the physical separation of SS occurs under quiescent conditions in the primary clarifier, where suspended solids are allowed to settle and to consolidate on the clarifier bottom. Raw primary sludge results when the settled solids are hydraulically removed from the tank. The relative solid and liquid fractions of a slurry are most commonly described by the solids concentration, expressed as mg/L or percent solids. The purpose of the present investigation is to estimate a suitability on the design capacities of residuals treatment facilities by the quantity of dewatered sludge generated from water treatment plants.

• Journal of Korean Tunnelling and Underground Space Association
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• v.11 no.4
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• pp.353-359
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• 2009

As ground water influx quantity which flows into the tunnel inside from the 7.937 km section of Han River and small and 7 medium-sized rivers which pass through subway line 5 is average $34,444\;m^3/day$ and it's 55.3% of the underground water influx quantity $62,272\;m^3/day$ which flows into whole tunnel section 31.29 km. If we suppressed the underground water influx from the rivers, it would be expect that the maintenance and management expenses would be able to reduce a lot. In addition, as the result of investigating the difference between the ground water influx quantity which flows into the river section and that of the design standard, the ground water influx quantity is $3.01\;m^3/min$ and it is flowing to similar level of tunnel design standard $3.00\;m^3/min$. However, when it is compared with tunnel average influx quantity $1.38\;m^3/min$, it has been found that 2.18 times of ground water flows into rivers.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.1
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• pp.123-130
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• 1992

The quantity point has been considered prior to the quality point in the water resources development and management. However, the quality problems have become as important as quantity problems due to the industrialization and civilization. This paper presents a methodology of the integrated management of multiple reservoir systems by considering both water quantity and quality problems. It also presents a long-term forecasting technique of reservoir water quality by using the developed phosphorous model. The methodology was applied to the Han river reservoirs operation, in which five major reservoirs were considered. The result shows that the spatially and temporally distributed water quantity and quality resources can be utilized by meeting all the required constraints.

• 한국기계연구소 소보
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• s.15
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• pp.117-125
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• 1985

It is usual practice to ballast a sip to maintain requires operational safety at sea. However, excessive ballasting may reduce the operational economy of a ship. Therefore, The determination of the optimal location and quantity of ballast water is one of the important works at the preliminary design stage. To provide a convenient tool to ship designers the program for the determination of the optimal location and program the effect of the change of ballast water quantity in each tank on some characteristics of a ship, such as trim, initial stability and heel, is investigated and the minimum quantity of ballast water for each tank which satisfies the operational safety requirements is calculated.

• Magazine of the Korean Society of Agricultural Engineers
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• v.22 no.2
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• pp.64-82
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• 1980

The aim of this thesis, when water permeates dam, is to study the shape of seepage line and seepage quantity. As for the process, various sand model dams of same capacity were constructed in the water tank : they are a central, middle, inclined, up and down stream point of which is paralled, and filter-installed types. And the slope of seepage line and seepage quantity in these various models for experiment were measured, observed data were analyzed, and several formulas which already published were compared and examined. As for the shape of seepage line, the relation between upstream water level and exit: slope of seepage line, near the entrance and exit point, geometrically similar model, and the shape of seepage line filter-installed were examined. As regards to the seepage quantity, several formulas which already published and testing result values were compared and examined, and relation with the slope of seepage line, the seepage quantity, the slope of upstream point, and the upstream water level were mutually studied. Particulary, when horizontal filter was installed, propriety of the existing formulas for effective filter length w as examined, and the relative position of exit point in various. conditions was also studied.

• Food Science and Preservation
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• v.18 no.4
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• pp.527-534
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• 2011

The purpose of this studies was analyzed moisture content, rheology and sensual test of jujube jungkwa by addition of water, sugar, fructose at processing of jujube jungkwa for development the optimization for processing of jujube jungkwa. The changes of moisture contents at process condition of jujube jungkwa were increased by increasing of sugar and water quantity. And moisture contents of jujube jungkwa were increased by high fructose quantity and low sugar quantity, but were decreased by high sugar and fructose quantity. The 'b' values of jujube jungkwa at low sugar quantity were decreased by the increasing of water quantity, but increased at high sugar quantity. The cohesiveness of jujube jungkwa at 0.03 kg of fructose were high by the increasing of sugar quantity, but those at 0.065 kg of fructose were high by the decreasing of sugar quantity. And those at 0.050 kg of fructose were similar without the quantity of sugar. The sweet taste of jujube jungkwa were increased by the increasing of water and fructose quantity. The characteristics of jungkwa at conditions of processing for the best quality of jujube jungkwa were 18-20% of moisture content, 2.0-3.0 of 'b' values, 3.0-3.2 of color scores, and 3.3-3.4 of sweet taste scores. The conditions of processing for the best quality of jujube jungkwa were determined to 0.95-1.04 L of water, 0.052-0.060 kg of fructose at 0.95 kg of sugar.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.3
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• pp.394-403
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• 2008

The effects of water injection (WI) and urea injection for NOx on a 4-cylinder Direct Injection (DI) diesel engine were investigated experimentally. For water injection, it was installed at the intake pipe and the water quantity was controlled at the intake manifold and Manifold Air Flow (MAF) temperatures while the urea injection was located at the exhaust pipe and the urea quantity was controlled by NOx quantity and MAF. The effects of WI system, urea-SCR system and the combined system were investigated with and without exhaust gas recirculation (EGR). Several experiments were performed to characterize the urea-SCR system, using engine operating points of varying raw NOx emissions. The results of the Stoichiometric Urea Flow (SUF) and NOx map were obtained. In addition, NOx results were illustrated according to the engine speed and load. It is concluded that the NOx reduction effects of the combined system without the EGR were better than those with the EGR-based engine.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.2
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• pp.44-48
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• 2004

A silent type ozone generator using water surface electrode was proposed. And it was investigated experimentally that a variation of water conductivity affected to water surface discharge. Important factors affecting to water surface discharge are ions in discharge space and ions and polarized molecules in water and so on. In this study, It was intended to change the characteristics of discharge by controlling the number of ions in water. The number of ions in water could be controlled by changing the water conductivity. Water conductivity was controlled by quantity of inserted NaCl to distilled water. At this time, current-voltage characteristics and characteristics of ozone generation quantity were investigated in each case. As a result, when NaCl was inserted in distilled water, more stable discharge was generated. As the quantity of NaCl was increased, discharge starting voltage could be lowered.