• Journal of Korean Society on Water Environment
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• v.39 no.1
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• pp.20-29
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• 2023

This study analyzed the relationship between harmful cyanobacterial abundance and environmental factors in order to figure out the causes of the recent increase of cyanobacteria in Lake Dukdong from 2019 to 2021. Lake Dukdong, which is used as a drinking water source for Gyeongju City, has an algae alert system in place. Lake Dukdong has maintained good water quality, but algae alert level 1 (over 1,000 cells/mL) has been issued in recent years. As a result of Pearson correlation analysis (from May to Oct.), the cell density of Microcystis and Aphanizomenon, which form part of the most harmful cyanobacteria genus, were significantly positively correlated with the water temperature and water storage volume. T-test was performed to compare the data from 2016-2018 and 2019-2021 (from May to Oct.). The average density of harmful cyanobacteria cells increased about six-fold from 54 to 344 cells/mL. There were significant differences in water temperature, pH, total nitrogen (TN), total phosphorus (TP), TN/TP ratio, water storage volume, and cyanobacterial cell density. Water temperature increased from 19.2 to 22.8 ℃. TP concentration increased from 0.017 to 0.028 mg/L. The main cause of the recent increase of harmful cyanobacteria in Lake Dukdong is thought to be the increase in water temperature, TP concentration, and water storage volume from 2019 and 2021, resulting in more favorable conditions for cyanobacterial growth.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.11
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• pp.1729-1737
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• 2007

A CRD experiment was conducted to evaluate the effects of different exogenous betaine levels (0.000, 0.075, 0.150 and 0.225 percent) on 576 one-day-old male broiler chicks (Ross) under water salinity stress. Different levels of water salinity were made by adding 3 levels of NaCl (0, 1,000 and 2,000 mg/L) to drinking water. Feed and water were available ad libitum. Betaine increased body weight, improved feed conversion ratio, and decreased packed cell volume (p<0.05). Water salinity promoted body weight over the whole period, increased feed intake (11 to 21 and 29 to 42-d) and also improved feed conversion ratio in grower and finisher periods (p<0.01). Breast weight, water consumption (28-d and 42-d) and excreta moisture (28-d) were increased by elevating the level of water salinity (p<0.01). Interaction between dietary betaine and water salinity was significant on plasma osmolarity as well as epithelial osmolarity of the duodenum at 28-d. Epithelial osmolarity was decreased from duodenum to ileum. The data imply that betaine is involved in the protection of intestinal epithelia against osmotic disturbance which can be caused by saline water, but further research is needed to investigate the effects of betaine with higher levels of water salinity.

• Journal of environmental and Sanitary engineering
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• v.14 no.1
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• pp.54-61
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• 1999

The industrial techniques of ultrasound have been used in the various fields, such as cleaning, medical surgery, emulsification, cell disruption etc. Especially the application of cell disruption was interested in the field of disinfection process in water by ultrasonic irradiation. It has been recognized that the ultrasounds are irradiated in aqueous solution, cavitation bubbles are generated and shock waves of high temperature and pressure are emitted as the bubbles are developed and finally broken, which function as a energy source to promote reaction efficiencies of various kinds of chemical reactions such as disinfection reaction in water. Therefore, this study was performed to apply the ultrasound for the disinfection method of infected drinking raw water and to discuss the limiting factors such as pH, sample volume and reaction temperature influenced on the removal efficiency of E. coli from experimental analysis of the results obtained in bench-scale plant. For the experiments to measure the influence of reaction parameters in the ultrasonic disinfection process, escalated reactivity of aqueous solutions was excellent when pH in aqueous solution was low, and sample volume was small. On the contrary, the reactivity of disinfection became elevated when reaction temperature was high. It was found that the rate constant of disinfection reaction was applied by Chick's law, reaction kinetics of Chick's law was irreversible and pseudo-first order at all the tested conditions.As a conclusion it appeared that the technology using ultrasonic irradiation can be applied to the treatment of disinfection in infected water which are difficult to be treated by conventional methods.

• The Korean Journal of Food & Health Convergence
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• v.5 no.6
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• pp.5-9
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• 2019

Desalination requires large energy. This experiment deals to desalinate brackish water through solar panels. The discharge from desalination plants is almost entirely water, and .01 percent is salt. Desalination is a process that extracts minerals from saline water. Solar-powered desalination technologies can be used to treat non-traditional water sources to increase water supplies in rural, arid areas. Water scarceness is a rising dilemma for large regions of the world. Access to safe, fresh and pure clean drinking water is one of the most important and prime troubles in different parts of the world. Among many of water cleansing technologies solar desalination/distillation/purification is one of the most sustainable and striking method engaged to congregate the supply of clean and pure drinkable water in remote areas at a very sound cost. Six types of dripper having discharge 3 - 8 lh-1 were installed one by one and measured discharge and volume of clean water indicated that at 6 lh-1 untreated water discharge have maximum evaporation and volume of clean water was 19.2 lh-1 at same temperature and radiations. Now strategy was developed that when increased the temperature the intake discharge of untreated water must be increased and salt drained water two times more than treated water.

• Safety and Health at Work
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• v.8 no.4
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• pp.327-328
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• 2017

Despite provision of drinking water as the most common method of occupational heat stress prevention, there remains confusion in hydration messaging to workers. During work site interactions in a hot and humid climate, workers commonly report being informed to consume tepid fluids to accelerate rehydration. When questioned on the evidence supporting such advice, workers typically cite that fluid absorption is delayed by ingestion of chilled beverages. Presumably, delayed absorption would be a product of fluid delivery from the gut to the intestines, otherwise known as gastric emptying. Regulation of gastric emptying is multifactorial, with gastric volume and beverage energy density the primary factors. If gastric emptying is temperature dependent, the impact of cooling is modest in both magnitude and duration (${\leq}5$ minutes) due to the warming of fluids upon ingestion, particularly where workers have elevated core temperature. Given that chilled beverages are most preferred by workers, and result in greater consumption than warm fluids during and following physical activity, the resultant increased consumption of chilled fluids would promote gastric emptying through superior gastric volume. Hence, advising workers to avoid cool/cold fluids during rehydration appears to be a misinterpretation of the research. More appropriate messaging to workers would include the thermal benefits of cool/cold fluid consumption in hot and humid conditions, thereby promoting autonomy to trial chilled beverages and determine personal preference. In doing so, temperature-based palatability would be maximized and increase the likelihood of workers maintaining or restoring hydration status during and after their work shift.

• Journal of Society of Preventive Korean Medicine
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• v.8 no.1
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• pp.59-74
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• 2004

We have conducted questionnaire and measured serum liver function tests on 153 patients whom have received a treatment at a local Oriental medicine clinic in Seoul from Sept. 1, 2002 to Dec. 31, 2002. Patients were categorized into the groups of control(10), decoction group(41), herbal group(5), western medicine group(45), and the group taking both herbal and western medicines(55) concurrently or separately. This study was conducted to investigate how these treatment methods can affect the liver functions. Following results were obtained : 1) Most of the research subjects were male(l03 individuals) living in large urban area, with drinking habit, highly educated, and with normal marriage. For the treatment history, 45 individuals received western medicine treatment(28.85%), 46 with Oriental medicine (29.49%), and 55 patients(35.26%) experienced both forms of treatment. 2) Measuring SD of serum liver functions for all the research subjects, T-protein was 6.95(0.73)g/dl, 4.07(0.51)g／dl for albumin, 0.44(0.19)mg／dl for T-bilirubin, 23.18(18.68)U／L for ALT, 27.42(27.43)U／L for AST, and 22l.27(64.58)mg／dl for LDH. 3) Among the research subjects with the liver functions outside of normal range were 0.64% for T-protein, 3.21% for T-bilirubin and ALT, 36.62% for AST, 0.64% for LDH, and none for Albumin. 4) Confusion variables which may affect the liver functions such as age, smoking, drinking, occupation, and residence were eliminated in calculation and no significant differences were witnessed between the control and experiment groups. 5) In measuring affects of treatment duration on the liver functions, no statistical significances were shown in multiple regression's ,${\beta}$(SE) values. 6) The values of odd ratio in the experiment groups compared to the control were in the range of $0.26(0.22){\sim}0.62(1.23)$. but T-bilirubin of the group receiving both Oriental and western medicine was 1.47(1.90) which showed statistical increase(p<0.001). 7) Factors affecting the liver functions are drinking volume per round duration of alcohol intake, western medicine treatment, gender, and age difference caused significant influences. 8) 57 individuals with serum liver functions out of normal range were mostly male, living in large urban area, median age of 38.89, with normal marriage, highly educated drinking less than once a week with less than 2 bottles per round, and with prior treatment in either western or Oriental medicine. Summarizing above results, we can carefully deduce that taking herbal medicine (both decoction and pills) or western medicine doesn't cause much affect in the liver functions. But taking two forms of medication simultaneously or altering dosage affect significant increase in the T-bilirubin level, thus one needs to take precaution when taking both. Further research is needed in this field to verify this evidence.

• Korean Journal of Biological Psychiatry
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• v.5 no.2
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• pp.235-242
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• 1998

Objectives : Alcohol-induced oxidative stress has been known to injure various tissues or organs. This stress is related with free radicals which are produced as the result of long-term alcohol consumption. Malonyldialdehyde(MDA) is produced by the interaction of free radicals and cell membrane lipids, and indicates the degree of lipid peroxidation indirectly. The purpose of this study was to investigate the relationship between red blood cell(RBC) membrane lipid peroxidation by free radicals, and associated hepatic injuries and hematologic changes. Methods : Thirty-three subjects diagnosed as alcohol dependence according to DSM-IV diagnostic criteria were evaluated within 72 hours after discontinuing alcohol drinking. Clinical characteristics were evaluated by CAGE questionnaire and Korean Michigan Alcoholism Screening Test(MAST). RBC membrane MDA level was measured as the marker of RBC membrane lipid peroxidation. Aspartate aminotransferase(AST), alanine aminotransferase(ALT) and gamma-glutamyltransferase(GGT) were used as the biochemical markers of liver damage due to alcohol ingestion. The alcohol-induced hematologic change was assessed by mean corpuscular volume(MCV). Results : The results were as follows. Clinical characteristics were not different between two groups having normal and abnormal levels of AST, ALT, GGT or MCV. The levels of MDA were not correlated with the clinical characteristics and serum levels of AST, ALT and GGT. However, there was a significant correlation between the levels of MDA and the value of MCV(p=0.017). Conclusions : These findings suggest that oxidative stress in alcohol dependence may not be reflected in liver enzyme markers such as AST, ALT and GGT, but may be reflected in MCV.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.1
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• pp.77-85
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• 2016

The characteristics of filter/adsorber granular activated carbon (F/A GAC) were investigated by measuring various parameters, which include surface area, pore volume, abrasion number, floater, and water-soluble ash. The correlation between parameters was also evaluated. Moreover, rapid small-scale column test (RSSCT) was conducted for adsorption characteristics. Thirteen F/A GAC were tested, and the average values of abrasion number and water-soluble ash were 88.9 and 0.15%, respectively. F/A GAC with the larger external surface area and greater mesopore volume had the lower abrasion number, which indicated that it was worn out relatively easily. Water-soluble ash of coconut-based GAC (about 2.6%) was greater than that of coal-based GAC (less than 1%), and the pH of solution was increased with GAC, which had the higher water-soluble ash. On the other hand, floater of thirteen F/A GAC was divided as two groups, which one group had relatively higher floater (2.7~3.5%) and the other group had lower floater (approximately 0.5%). The results of RSSCT indicated that coconut-based GAC (i.e. relatively higher water-soluble ash) had less adsorption capacity. Moreover, adsorption capacity of coal-based GAC with larger surface area and greater mesopore volume was superior to others.

• Journal of Fisheries and Marine Sciences Education
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• v.18 no.3
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• pp.374-378
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• 2006

Eel is Anguilla japonica and Anguillidae family as a freshwater fish, and Japanese name is Unagi. The content of vitamin A of eel muscle are about 4,000IU/100g and they have many effective components, so it is known as healthy food. Therefore, many people have eel that cooked roast and hot-water extract in Korea. WHO encouraged that daily edible content of vitamin A is 2,000IU. Now, Japan government proposes the weight of roasted eel in lunch basket as 50g. But, Korea government does not proposes in every related aspects. Therefore, we researched content of vitamin A in hot-water extract from eel and optimal processing condition of hot-water extract from eel, in order to determine a proper edible volume. The content of vitamin A in eel hot-water extract sold at a market was about 200 IU. This study resulted from the fact that many eel hot-water extracts lacked the vitamin A. The reason was that the lipids were removed for taste on processing. But, The content of vitamin A in eel hot-water extract which didn't removed lipid on processing was about 800IU. Therefore, in drinking for 3packs per day, eel hot-water extract might have adjusted 100mL per pack which is almost consistent with the recommended dietary allowance of vitamin A in WHO.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.10a
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• pp.237-241
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• 2003

The world's supply of water in all forms is enormous. However, only a tiny fraction of the planet's supply is available to us as fresh water, and that is distributed very unevenly. About 97％ of oater volume is found in the oceans and is too salty for drinking, growing crops, and most industrial uses except cooling. In addition water supply crises in already-water-short-regions will intensify because population and industrialization increase. Today, remote monitoring and control systems are becoming the cost-effective management tools for almost all water user groups, including irrigators, water districts, municipal water suppliers, and wildlife management groups. This paper represents a new approach in the water-gate control using radio communication. The proposed device is simple in structure and suitable for implementation of water-gate control through the transceiver by radio communication. It was confirmed that the developed device was very efficient to control level of water-gate and to prove the up and down motion of water-gate through the LCD displayer.