• Journal of Korea Water Resources Association
• /
• v.41 no.8
• /
• pp.773-784
• /
• 2008

The present study was carried out to examine flow properties in linear drainage channels such as road surface drainage facilities. The finite difference formulation for the varied flow analysis was solved for flow profiles in the channels. Starting the first step at the control section, the Newton-Raphson method was applied for producing numerical solutions of the equation. We considered two types of linear drainage channels, a channel with one outlet at downstream end and a channel with two outlets at both ends. Moreover, the flow analysis for various channel slopes was performed. However, we considered channels with the two outlets of slopes satisfying the condition that the both ends are the control section. The maximum of those slopes was decided from the relation between the channel slope and the location of control section. The flow of a channel with one outlet was calculated upward and downward from the control section existing in channel or upward from the control section at downstream end. The flow of a channel with two outlets at both ends were calculated for upstream and downstream channel segments divided by the water dividend, respectively and the flow analysis was completed when the water depth at the water dividend calculated from upstream end was equal to that calculated from downstream end. If the slope was larger than the critical slope, the channel with two outlets was likely to behave like the channel with one outlet. The maximum water depth was investigated and compared with that calculated additionally from the uniform flow analysis. The uniform flow analysis was likely to lead a excessive design of a drainage channel with mild slope.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.42 no.4
• /
• pp.493-499
• /
• 2022

The standards pertaining to the quality of discharged water in sewage treatment plants are strengthening, and accordingly, facilities in sewage treatment plants are being upgraded. In addition, the discharge water quality of sewage treatment plants must be maintained at a high level, and efficient sewage treatment plant operations have thus emerged as a very important issue. For the efficient operation of sewage treatment plants, this study applied a basic blowing amount calculation method based on sewage facilities to evaluate the required oxygen amount and blowing amount according to inflow water quality by logicizing various influencing factors. As a result of calculating the amount of air blown by applying actual April water quality data from sewage treatment plant A to the blower demand calculation developed through this study, it was found that the average amount of air blown was reduced by about 12%. When the blower demand calculation developed here is applied to an actual sewage treatment plant, the amount of air blown can be controlled based on the inflow water quality. This can facilitate the realization of an autonomous control of sewage treatment plants, in contrast to the existing sewage treatment operation method that relies on operational experience of operator. In addition, it is expected that efficient sewage treatment plants can be operated by reducing blowing amounts and power costs, which will contribute to both energy and carbon savings.

• Applied Chemistry for Engineering
• /
• v.21 no.2
• /
• pp.169-173
• /
• 2010

Many salts have the ability to attract and remove water vapor from the surrounding environment. The ability of each salt to remove water vapor is based on the flow rate and temperature of air in surrounding. The objective of this study was toinvestigate the humid control characteristics in air-water system by using a desiccants. The aim is to asses the influence of three parameters on the humid control process which are air volume rate, air temperature and desiccant amount. Humidity control materials which consist of K (potassium) or Na (sodium) have been synthesized by the aqueous process. The humidity control properties of materials have been also investigated. Experiment results are as following. Thermal characteristics of desiccants showed similar properties regardless of processing condition. The experiments were examined by using artificial air-water system (humidity : 70~93%, air volume rate : $0.22{\sim}0.69m^3/s$). The results showed that the Na-type desiccant was an effective material. It was found that dew point increased with air volume rate, and the humidity change in humid control process was depended on desiccants amount.

• Journal of Advanced Marine Engineering and Technology
• /
• v.33 no.8
• /
• pp.1129-1136
• /
• 2009

The paper presents the performance characteristics for a cooling system using EEV. The water cooler was used to reduce thermal deformation and contraction due to high speed of machine tools and the EEV was used for capacity control for water cooler. The apparatus was designed for hot-gas bypass system which a hot-gas can flows from outlet of compressor to the inlet of evaporator. This experiment is the intermediary study for precise temperature control through PID control. The results show that the evaporator pressure increased and refrigeration capacity decreased as the EEV opening step of hot-gas bypass increased. These results can be used as basic data for the design of effective water cooler.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.3 no.1
• /
• pp.80-90
• /
• 2000

This study was carried out to introduce current status and development strategy for an environmental restoration of stream side in Japan, and to consider a methodology which could be effectively applied for the environmental restoration of stream side in Korea. Since the end of 20th century, the native ecology and landscape of Japan remained only a limited areas such as stream side, water side and forest areas. Therefore, recently the works of forest conservation and erosion control of environmental restoration on stream side tended to increased. The strategic prospects of environmental restoration in Japan were summarized as follows : 1. From the ecological point of view, we have to develop a certain method and technology in construction of forest conservation and erosion control to prevent environmental problem from erosion control works. 2. We have to restore not only a continuity of stream side forest from a primitive area to an estuary but also the stream side forest to preserve and restore a stream side vegetation on a primitive watershed areas. 3. We have to improve a method of construction or removal of a structure which were constructed in the stream to restore a water side environment and an interaction system for an integration on a forest land, stream, and erosion control. Additionally, we have to establish an integrated evaluation method and an enforcement system after investigation of influences on natural environment, stream, and forest etc. 4. We have to conduct an integrated research to investigate the ecosystem of stream side, and construct environmentally friendly water park and erosion control park which considered natural environment and its landscape. Additionally, we need to introduce and adopt a natural style stream construction method to restore a water side areas.

• Korean journal of food and cookery science
• /
• v.27 no.3
• /
• pp.95-104
• /
• 2011

This study was conducted to investigate the effect of red wine on the quality properties and sensory score of seasoned pork meat. Pork meat was treated with 25% water (control), 20% water and 5% red wine (RW5), 15% water and 10% red wine (RW10), or 10% water and 15% red wine (RW15). The moisture, crude protein, crude fat, $L^*$ value, springiness, cohesiveness, gumminess, chewiness, and VBN content were not significantly different among the samples. Cooking yield, moisture retention, and fat retention were significantly higher in the RW5, RW10, and RW15 (p < 0.05) compared to those in the control. The $a^*$ value of RW5 was the highest among the samples, and the $b^*$ value increased significantly in the control and RW5 (p < 0.05). The hardness of the control was the highest among all samples (p < 0.05). The pH was significantly lower in RW5, RW10 and RW15 (p < 0.05) compared to that in the control. The TBARS value and total bacteria were significantly lower in RW5, RW10, and RW15 (p < 0.05) compared to those in the control. Adding red wine altered the fatty acid and free amino acid of cooked seasoned pork. These results suggest the possibility that red wine could be used an additive to improve the quality of cooked seasoned pork.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.15 no.6
• /
• pp.61-67
• /
• 2012

This study was conducted to evaluate the effects of soil covering and vegetation base materials implementation on the growth of Lespedeza cyrtobotrya Miq. in abandoned coal mine land. We compared the biomass of L. cyrtobotrya at the study plots of four different soil covering depth (control, 10cm, 20cm, and 30cm) and four different compounds of vegetation base materials composed of soil conditioner (S), erosion control (E), and peat moss (P) (control, S+P, E+P, and S+E+P). The result showed that the biomass of L. cyrtobotrya was higher in the study plots implemented with soil covering than control plot, although the increase in biomass was not constant with soil covering depth. In case of the vegetation base materials treatments, the biomass was highest in S+E+P plot, and S+P and E+P plots showed higher biomass than control plot.

• Korean Journal of Veterinary Research
• /
• v.31 no.4
• /
• pp.419-424
• /
• 1991

This study was carried out to investigate; the alpha-fetoprotein, urea and free fatty acid in amniotic fluids and water filled multiple T-maze test of fetuses affected by Ethylenethiourea. The S.P.F. Sprague-Dawley female rats(10 weeks) were used in this study and these animals were divided into four groups; control group I (10mg/kg/day), group II(30mg/kg/day), group III(50mg/kg/day). The results obtained were summarized as follows; 1. In the water filled multiple T-maze test of F1 male rats, The time and errors from start point to goal point of 30mg/kg group are significantly(p<0.001) increased from control group in 3rd day of test. In F1 female rats of 2nd day and 3rd day of water filled multiple T-maze test, The time and some errors in 30mg/kg group are significantly (p<0.05) increased from control group. 2. Alpha-fetoprotein values of all treated groups(10mg/kg, 30mg/kg and 50mg/kg) were significantly(p<0.001) decreased from control values in the amniotic fluids. 3. Urea values of ammniotic fluids in 50mg/kg group are significantly increased from control group. 4. Free fatty acid values of ammniotic fluids in 50mg/kg group are significantly increased from control group.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.24 no.2
• /
• pp.147-154
• /
• 2014

In this study, chlorine modeling technique based on fuzzy system is proposed to reduce the carcinogenic substance and decide the optimal chlorine injection rate, which is affected by chlorine evaporation rate in sedimentation basin according to detention time, weather and water quality. The additional chlorine meter is installed in the inlet part of sedimentation to reduce the feedback time and implement cascade control, which leads to maintaining the residual chlorine concentration decided by fuzzy rule. It helps to take a preemptive action about long time delay, the characteristics of the disinfection process, and reduce the variation of residual chlorine rate by 7.3 times and the chlorine consumption by 40,000 dollars. It made a significant contribution to supply hygienically safe drinking water.

• Journal of Nutrition and Health
• /
• v.41 no.1
• /
• pp.5-12
• /
• 2008

In order to investigate whether Eisenia bicyclis (EB) as a functional food material improves serum lipid status, supplementation of EB powder or EB extract to the high fat/cholesterol diet was tested in 6-week old male Sprague-Dawley rats for four weeks. In the first experiment, four kinds of seaweed powder -Eisenia bicyclis (EB), Undaria pinnatifida (Up), Laminaria japonica (LJ), and Ecklonia stolonifera (ES) were compared with alginic acid (ALG) as well as control. In the second experiment, EB water extract and EB ethanol extract and EB pill containing EB and LJ powder were compared with the EB powder. Amounts of dietary fiber contained in experimental diets were adjusted to provide 5% of diets. Serum total cholesterol was significantly lower only in rats fed LJ or EB powder, but HDL cholesterol was higher in rats fed UP, LJ, ES or EB powder. Ratios of HDL-/total cholesterol of all seaweed groups including ALG were significantly higher than that of the control group. Serum triglyceride was lower in LJ, EB nd ES powder groups than the control group. In comparison of EB extracts, triglyceride level was decreased in rats fed only EB water extract as compared to control rats, but HDL cholesterol was elevated with both water and ethanol extracts. Serum levels of total cholesterol, triglyceride were decreased and HDL cholesterol was increased by the EB pill. Serum levels of thiobarbituric acid-reactive substances were lower in rats fed ES powder, and EB powder, EB water extract or EB pill, as compared to the control rats. Supplementation of EB powder and EB pill reduced serum level of GOT and GPT, respectively, as compared to the control group. In conclusion, EB and EB pill improve serum lipid status and may be utilized as ingredient of functional foods for the purpose of improving serum lipid profile and inhibiting peroxidation of lipids.