• Journal of the Korean Professional Engineers Association
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• v.28 no.1
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• pp.45-53
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• 1995

본보문은 일본의 건설성토목연구소환경부에서 발표한 내용을 요약한 것으로서 오늘날 우리나라 저수지에서도 적용함이 타당하다고 사료되어 여기에 그 내용을 소개하는 바이다.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.11a
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• pp.269-270
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• 2018

• Journal of Bio-Environment Control
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• v.21 no.3
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• pp.236-242
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• 2012

This study was carried out to investigate the effect the water content in coir substrates as according to growth stage on the growth and yield of mini-paprika of three varieties 'E 499524' (red color), 'E 499526' (yellow colar) and 'E 499531' (orange colar) in summer hydroponics. Treatments of I, II and III were composed of 55-65-60, 50-60-55 and 45-55-50% in water contents of growth stages, respectively. Time domain reflectometry (TDR) sensors were used in a drip irrigation system. The early growth of mini-paprika was increased by high medium water content of treatment I in all of three varieties. Mean fruit weight was not affected by medium water content, but the fruit number per plant and yield were increased at high medium water content of treatment I. The Yield of treatment I was higher than that of treatment II and III in all of three varieties. The sugar content was increased by low medium water content of treatment in all of three varieties. The incidence of brown-stem fruit, blossom-end rot and sunburn was decreased with increasing water content of medium. Occurred in the low water content of medium. Mineral contents of fruits such as nitrogen (N), potassium (K), calcium (Ca), magnesium (Mg) etc. were not affected in all of three varieties.

• Applied Microscopy
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• v.41 no.3
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• pp.197-204
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• 2011

To investigate the alleviative effect of white tea water extract on the inflammation and skin barrier damage, skin aging animal model was produced by the irradiation of UVB to the backs of hairless mice for 12 weeks. And then experimental materials were applied topically for 4 weeks. At the 28th day of experiment, positive control (PC, 0.01% retinoic acid treatment) and experimental groups (E1, 1% white tea water extract treatment; E2, 2% white tea water extract treatment) had significantly (p<0.001) lower values of both skin erythema index and transepidermal water loss (TEWL) than the control (C, saline treatment) group. The appearance of mast cell and the degree of its degranulation in dermal and subcutaneous layers were remarkably reduced in E1 and E2 groups compared to the C group. It is found that white tea water extract is effective in skin barrier damage and inflammation in hairless mouse.

• The Journal of the Korean dental association
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• v.56 no.4
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• pp.194-207
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• 2018

Objectives: The water fluoridation program has been implemented since 2008 at the Daesan water treatment plant, Changwon City. The aim of this study is to evaluate caries preventive effect of permanent teeth from community water fluoridation program Methods: Evaluation surveys were conducted on 8-, 10- and 12-year olds in the fluoridated and non-fluoridated area of Uichang-gu and Seongsan-gu, Changwon City in 2015. The number of the subjects in 2015 was 722 in fluoridated area and 707 in non-fluoridated area. The caries preventive effect of permanent teeth by community water fluoridation was estimated by the differences in adjusted DMFT and DMFS scores between the program and control groups. Cofounders of mean number of fissure-sealed teeth or surfaces, and number of subjects by gender were adjusted to estimate the caries preventive effect of permanent teeth. Results: The mean DMFT score or DMFS score of children aged 8-, 10- and 12-years adjusted for the number of fissure-sealed teeth or surfaces in fluoridated area were significantly lower than those in non-fluoridated area in 2015. The caries preventive effect of permanent teeth estimated based on the difference of mean DMFT scores adjusted for fissure-sealed teeth, age and number of subjects by gender between control and program group among children was 37.3%. Conclusions: These results suggest that the caries preventive effect of permanent teeth from water fluoridation program at Daesan water treatment plant, Changwon City was so high that the water fluoridation program should be developed in other regions in Korea.

• Korean Journal of Plant Resources
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• v.25 no.4
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• pp.363-371
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• 2012

Sambucus williamsii var. coreana have been used as a traditional medical food. This research was conducted to investigate the antioxidants of S. williamsii var. coreana leave and stem extracts. Total phenolic content of S. williamsii var. coreana leaves and stem water extracts were 6.6 and 2.0 mg/mL. The EDA by DPPH free radical scavenging test of S. williamsii var. coreana leaves extracts were 99.5 and 89.7% in water and ethanol extracts contained phenolic 200 ${\mu}g/mL$. The stem extracts were 92.2 and 94.3% in water and ethanol extracts contained phenolic 200 ${\mu}g/mL$. The ABTS radical decolorization activity of water and ethanol extracts from leaves were 79.8 and 99.1% at phenolic 200 ${\mu}g/mL$ and water and ethanol extracts from stem were 90.8 and 97.2% at phenolic 200 ${\mu}g/mL$. The antioxidant protection factor of water and ethanol extracts from leaves were 1.1 PF and 1.1 PF at phenolic 200 ${\mu}g/mL$ and water and ethanol extracts from stem were 1.4 PF and 1.0 PF at phenolic 200 ${\mu}g/mL$. The TBARs of water and ethanol extracts from leaves were 88.7 and 98.1% at phenolic 200 ${\mu}g/mL$ and water and ethanol extracts from stem were 93.6 and 90.6% at phenolic 200 ${\mu}g/mL$. The antioxidative activities of extracts from S. williamsii var. coreana leaves and stem were higher than BHT as positive control. These results suggests that S. williamsii var. coreana extracts have the greatest property as a natural antioxidative source.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.2
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• pp.220-227
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• 1997

Water deficit stress during early soybean[Glycine max (L.) Merrill] growth stage is the most important environmental factor limiting productivity. Eight soybean genotypes were grown in replicated pot under well-watered(control: near 0 bar) and drought(-5 and -10 bars) conditions. Soybean plants were subject to drought stress for 20 days at 10 days after seed emergence. Significant genotypic variation was observed for leaf area(LA) and total dry weight (TDW). At the end of water stress, LA and TDW of Hwanggeumkong and Paldalkong, which had large LA in the non-stressed control, were more sensitive to water stress than those of the other cultivars, while those of Suwon 93 with small LA were insensitive. Leaf proline and abscisic acid(ABA) contents increased after water stress. However, changes in proline and ABA contents were not consistently related to the changes in LA as affected by water stress. As the soil water potential decreased, the yield reduction of Hodgson 78 showing large decrease in LA and TDW in response to water deficit was severe when compared to that of Baegunkong with small decrease in LA and TDW. Relatively greater yield stability and higher average yield across soil water potential were observed in Baegunkong. Of specific interest was the small reduction in yield of Paldalkong in spite of its significant decrease in LA and TDW.

• Journal of Korean Academy of Oral Health
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• v.42 no.4
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• pp.118-123
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• 2018

Objective: This study aimed to investigate the effects of fluoride-containing acidic tea beverages on bovine teeth surfaces. Methods: The pH values and fluoride concentrations of 11 kinds of mineral water and 23 kinds of tea were measured. The fluoride-containing Seopyenje black tea beverages with pH 3.48 were chosen for the experimental group. Distilled water that did not contain fluoride and had the same pH value as that of the Seopyenje black teas served as the positive control. The Jeju Samdasoo mineral waters with neural pH (pH 7.52) and no fluoride were chosen as the negative control. Bovine teeth in each group were submerged for 10 minutes. Thereafter, surface microhardness of each bovine teeth was measured and the results were analyzed. Results: The pH value range was 6.94-8.09 ($mean=7.37{\pm}0.08$) for the 11 kinds of mineral water and 3.48-6.74 ($5.62{\pm}0.05$) for the 23 tea beverages. Titratable acidity of the Seopyenje black tea beverages was higher than that of the distilled water mixed with citric acid, and the pH was 5.5 and 7.0, respectively. The fluoride content of the 11 kinds of mineral water was 0-1.09 ppm ($mean=0.44{\pm}0.02ppm$) that of the 23 tea beverages was and 0-0.74 ppm ($0.64{\pm}0.06ppm$). In terms of enamel microhardness reduction of the bovine teeth, the tea beverages had the largest effects. There was no significant difference in microhardness reduction between the tea beverages and distilled water mixed with citric acid (P>0.05). Conversely, a significant difference was found between the kinds of mineral water and tea beverages, and also between mineral water and distilled water mixed with citric acid (P<0.05). Conclusions: Acidic tea beverages appeared to erode the surfaces of bovine teeth. The amount of fluoride in the tea beverages was not enough to inhibit erosion. Therefore, frequent intakes of acidic tea beverage are likely to increase erosion on the surfaces of bovine teeth, by affecting the enamel microhardness of teeth.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.91-100
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• 2022

Ticks are the arthropod vector capable of transmitting diverse pathogens, which include bacteria, viruses, protozoan and fungi. Ticks are able to survive under stressful environmental conditions. One of evolutionary outcomes of these obligatory hematophagous arthropods is the survival for extended periods of time without a blood meal during off-host periods. Water conservation biology and heat tolerance have allowed ticks to thrive even under high temperatures and low relative humidity, thus they have become highly successful arthropods as they are distributed globally. Tick osmoregulatory physiology is a complex mechanism, which involves multiple osmoregulatory organs (salivary glands, Malpighian tubules, hindgut and synganglion) for the acquisition and excretion of water and ions. Blood feeding and water vapor uptake have been early reported as the primary passages for ixodid tick to acquire water. Recently, we have learned that ticks can actively drink environmental water allowing hydration. The acquired water can be traced to the salivary glands (type I acini) and the midgut diverticula. This opens new avenues for tick management through the delivery of toxic agents into their drinking water, in addition to an alternative strategy for the study of tick physiology. Here we address the osmoregulatory physiology in the ixodid ticks as a potential target physiological mechanism for tick control. We discuss the implications of water drinking behavior for tick control through the delivery of toxic agents and discuss the dermal excretion physiology as an additional pathway to induce tick dehydration and tick death.

• Horticultural Science & Technology
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• v.19 no.4
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• pp.596-601
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• 2001

This study was carried out to determine the effect of base carriers such as zeolite or vermiculite on change of concentration of polyoxyethylene laury ether[$C_{12}H_{25}O(C_{2}H_{4}O)_{3}H$, PLE] and on initial wetting of peat-vermiculite medium in the development of a soil wetting agent using the mixture of PLE and polyoxyethylene+polyppro-pyleneoxide tridecylether (1:1, w/w, CM-1). The concentration of PLE in the treatment of vermiculite was higher than that of zeolite during the period from 2 to 6 weeks. The cumulative concentration of PLE released in the treatment of vermiculite was about $2800mg{\cdot}L^{-1}$ and zeolite was about $2300mg{\cdot}L^{-1}$. The treatments of PLE+CM-1 with zeolite or vermiculite as a carrier were effective in initial water retention of root media having more than 510 mL of water per pot, where as those of $AquaGro^{G}$ and control had 490 mL and 400 mL of water per pot, respectively. In the evaporative water loss, the treatment of zeolite and $AquaGro^{G}$ were faster than that of control and vermiculite. The control treatment had the fastest water movement in and the highest volume of water infiltrating into root medium among all treatments. Increased application rate of PLE+CM-1 did not increase water retention capacity. The treatment of $0.6g{\cdot}L^{-1}$ had the highest evaporative water loss and that of $0.3g{\cdot}L^{-1}$ had the highest amount of water infiltrating into root media among all other treatments.