• Journal of Environmental Science International
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• v.4 no.3
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• pp.207-220
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• 1995

In order to study on the long-term change of water quality, water analysis was conducted at 16 sites surrounding the Kumho river system for 11 times from September 1990 to August 1993. Analytical items for the study of water Quality are as follows; water temperature, pH, COD, BOD, DO, SS, electrical conductivity, $NH_3-N$, $NO_2^-N$, NO_3^-N$, $PO_4^{3-}-P$, total-P, hardness, oil and grease, ABS, phenol, zinc, chromium, cadmium, manganese, iron, lead and color. The long-term change of water quality in the Kumho river for the period studied was found that the values of water temperature, electrical conductivity, phenol, $NO_2^-N$ and $NH_3-N$ were increasing and those of COD, BOD, SS, oil and grease, ABS, NO_3^-N$, $PO_4^{3-}-P$, copper, zinc, chromium, cadmium, manganese and lead were decreasing, while those of pH, hardness, iron and manganese were steady.

• Journal of Technologic Dentistry
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• v.19 no.1
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• pp.43-54
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• 1997

This investigation is carried out of inqurie into the effects of the accelerator on the setting time and haedness when it is used with plaster products. Plaster($\beta$), dental hard stone($\alpha$), and limproved dental hard stone($M{\alpha}$) are selected as the objects of the investigation, since they are most common materials for dental plaster products. Setting time is gauged by means of Vicket Needle and Gilmore Needle, and hardness is gauged by means of Brinell and Vicket Hardness machines. Samples of each material are made in the standerd water powder ratio and with the accelerator repectively, Every material is tested five times each. The results of the tests are as fallow : 1) In each case the setting time is shortened when the accelerator is used. 2) Of the three materials the hardness of the plaster was lowest A($\beta$) < B($\alpha$) < C($M{\alpha}$)} 3) In each case the hardness of the samples made in the standard water powder ratio were higher than that of the sample made with the accelerator. A1 > A2 ; B1>B2 ; C1>C2 4) Final Conclusion : Higher quality cast is expected when it is made in the standard water powder ratio.

• Journal of Life Science
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• v.18 no.4
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• pp.503-508
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• 2008

Deep sea water from the East sea was tested for breast cancer chemoprevention and metastasis by measuring the activities of cytochrome P450 1A1 and aromatase, invasiveness, and activity and expression of matrix metalloproteinase (MMP)-9 in breast MDA-MB-231 cancer cell. The in vitro incubation of rat liver microsome with deep sea water (a hardness range of $100{\sim}1,000$) showed a hardness-dependent inhibition of 7,12-dimethylbenz[a]anthracene (DMBA)-induced cytochrome P450 1A1 activity. Deep sea water showed 27.1, 45.4 and 51.9% inhibition of microsomal aromatase activity at the hardness of 600, 800 and 1,000, respectively. In addition deep sea water inhibited not only the invasiveness of 12-O-tetradecanoylphorbol-13-acetate (TPA)-treated MDA-MB-231 cells through matrigel-coated membrane in a hardness-dependent manner but also the activity and expression of MMP-9 in MDA-MB-231 cell.

• Journal of Aquaculture
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• v.15 no.1
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• pp.49-60
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• 2002

Research on practices for improving water quality in channel catfish Ictalurus punctatus ponds was conducted at the Auburn University Fisheries Research Station, Auburn, Alabama, in 1998 and 1999. The objective of this two-year study was to determine better management practices to enhance water quality and improve production efficiency. In the first year, oxidation of bottom soil by drying, tilling, and applying sodium nitrate was performed (dry-till and dry-till with sodium nitrate treatments). The second year, based on the results obtained during the first year, precipitation of phosphorus (P) from water by applying gypsum was compared to the dry-till treatment (dry-till and dry-till with gypsum treatments). Control ponds were not subjected to bottom drying, tilling, sodium nitrate, or gypsum treatment. Channel catfish fingerings were stocked at 15,000/ha. In the first year, water in ponds from dry-till and dry-till with sodium nitrate treatments had lower concentrations (P < 0.01) of soluble reactive P, nitrate ($NO_{3} ^{-}) and nitrite ($NO_{2} ^{-}) nitrogen (N), total ammonia ($NH_3$) nitrogen, total suspended solids and turbidity, and higher values of pH, Secchi disk visibility, total alkalinity, total hardness, and calcium ($Ca^{2+}) hardness than water in control ponds. Ponds of the dry-till treatment also had lower concentrations (P < 0.01) of total P and total N than control ponds. Total fish production and survival rate did not differ among the treatments (P > 0.05). The findings suggested that drying and tiling pond bosoms between crops could achieve water quality improvement. Applying sodium nitrate to dry, tilled pond bosoms did not provide water quality improvement. In the second year, the treatment with the best results from the first year, dry-till, was compared with a dry-till with gypsum treatment. Enough gypsum was applied to give a total hardness of about 200 mg/L, and gypsum was reapplied as needed to maintain the hardness. Compared to the control, dry-till and dry-till with gypsum treatments had lower concentrations (P < 0.01) of total and soluble reactive P, total N, and total $NH_3$-N, and higher concentrations (P < 0.01) of dissolved oxygen. Ponds of the duty-till with gypsum treatment also had lower concentrations (P < 0.01) of chlorophyll $\alpha$, chemical oxygen demand, and total alkalinity than the control. Total fish production and survival rate did not differ (P > 0.05) among the treatments. These findings suggest that drying and tilling pond bosoms between crops and treating low hardness waters with gypsum could achieve water Quality improvement.

• Korean Journal of Human Ecology
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• v.5 no.1
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• pp.81-88
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• 1996

The effects of water to rice ratio on the properties of cooked nonwaxy and waxy rice during storage were investigated by sensory evaluation and instrumental test by Instron. The result of sensory evaluation revealed more significant difference in most of texture characteristics than flavour. As the water to rice ratio increased, the moisture content of cooked rice increased and the value of moistness and plumpness increased but that of hardness decreased. Overall eating quality was the highest in cooked nonwaxy rice with 1.4(water/rice) and in cooked waxy rice with 1.2(water/rice). In the case of instrumental test, hardness showed highly significant difference and the value of hardness of nonwaxy cooked rice was greater than that of waxy cooked rice.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.3
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• pp.455-459
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• 2001

Tofu (soybean curd) was made with whole soybean flour (WSF, 420 mesh) by various processing conditions of water addition ratio, heating time, coagulation temperature, molding pressure and 0.3% of mixed coagulant (CaSO₄:GDL=50:50(w/w)). Yield content of WSF-tofu was the highest in processing condition of 85℃ coagulation temperature, 10 times water addition, 5min. heating time and 25.00 g/㎠ molding pressure. As the increase of the water addition ratio from 8 to 14 times (water:WSF, v/w), Hunter's L and a values were increased. Raising of heating time (100℃, 1, 5, 10 and 15 min), a and b value were increased. Textural properties of WSF-tofu were significantly affected by coagulation temperature (75, 80, 85 and 90℃). Hardness was increased, but adhesiveness and cohesiveness were decreased. heating time was influenced on harness of WSF-tofu, but water addition ratio was not affected on hardness of WSF-tofu. Increasing of molding pressure (16.83, 25.00, 33.22 and 41.67 g/㎠, 1 hr) was resulted from a increased hardness, gumminess and chewingss of tofu, but adhesiveness was addition ratio, 5 min heating time and 25.00 g/㎠ molding pressure recorded the highest score in sensory evaluation test.

• Journal of Korean Society on Water Environment
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• v.30 no.2
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• pp.206-211
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• 2014

This study was done to find chemicals adequate to control alkalinity and hardness in order to reduce dissolved phosphorus in water bodies like rivers and lakes. Five chemicals were selected for the study: calcite, lime, dolomite, magnesite, and gypsum. Data were obtained from the calculations with MINTEQ model as a function of dosage variations of each chemical. Findings are as follows: Three out of the five chemicals are found to be effective in reducing the dissolved phosphorus, i.e., calcite, lime, and dolomite. Calcite and dolomite are able to lower the phosphorus concentration up to one thousandth fold whereas lime does one hundred thousandths fold. In viewpoint of pH variation, both calcite and dolomite seem to be safe since the pH does not increase over 8.3 even in case of overdose. In the same circumstance, with lime the pH increases beyond 9 which is considered to be the highest pH level for the protection of water ecosystem. Nevertheless it is recommendable to use lime in case where there are some difficulties in water quality control due to algae blooms.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.29 no.1
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• pp.135-150
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• 2003

This study is described the stabilizing technology of water-in-oil (w/o) emulsion and the mechanism of emulsification with quaternium-18 hectorite (Q-18 HTRT) by swelling action. When Q-18 HTRT is dispersed in oil, it swells and constructs card-house structure adding ethanol, and formation of water phase is caused by hydrogen bonding. The gelling activities of Q-18 HTRT were excellent such as mineral oil, squalane, cetostearyl isononanoate, isostearic acid, cetyl octanoate, octyl dodecanol and so on. Especially, when oil gel containing Q-18 HTRT passed one to three times by Roll mill. It made the W/O emulsion cream (W/O-ECRM) having 2.0 w/w% of Q-18 HTRT and also produced the control sample (control) including 3.0 w/w% of cetyl PEG/PPG- l0/l dimethicone. The stability of after 24 weeks, Hardness of W/O-ECRM dropped 7.48%, whereas hardness of control went down 57 71%. As a result of these test emulsification of W/O-ECRM is superior compared with control. In cosmetic, 0-18 HTRT can use as suspending agent, oil adsorbent, emulsifying agent, dispersing agent, viscosifier and pigment.

• Journal of environmental and Sanitary engineering
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• v.21 no.3 s.61
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• pp.9-14
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• 2006

From March 1, 2005 to August 31, 2006 mineral water wells were selected for 13 areas in Southeast Asia (Indonesia, Philippines, Thailand, Singapore) and 20 areas in Northeast Asia (Korea, North Korea, China, Japan) and the study on their mineral water quality was analyzed. - Mineral water quality was the best in Korea. Mineral spring waters in some area of China and North Korea and in the whole area of the Southeast Asia were of poor quality. - The hardness of mineral water was the low in Korea $(10{\sim}47mg/L\;as\;CaCO_3)$, Japan $(4{\sim}66mg/L\;as\; CaCO_3)$, Geumgang-san North Korea Area $(4mg/L\;as\;CaCO_3)$. Mineral spring water in Thailand, Indonesia $(1{\sim}97.5mg/L\;as\;CaCO_3)$ and in the other area $(120{\sim}1205mg/L\;as\;CaCO_3)$ were high degree of hardness. - pH value in the mineral water of Southeast Asia $(pH\;6.7{\sim}8.2)$ and Northeast Asia $(pH\;5.9{\sim}7.9)$ was up to WHO standard $(pH\;6.5{\sim}8.5)$. Fluorine of negative ion was found in 10 mineral waters: Indonesian mineral water 'ATARTN'(0.02mg/L), Thailand mineral water 'SIAM' (0.6mg/L), 'MASAFI' (0.02mg/L). Korean mineral water 'SAEMMULNARA' (1.1mg/L), 'SANSU'(0.6mg/L), 'ICIS'(0.3mg/L), 'DONGWON SAEM-MUL'(0.03mg/L), 'PYEONGCHANG' (0.6mg/L), North Korean mineral water 'KUMGANGSAN'(0.1mg/L), Japanese mineral water 'CRYSTAL GEYSER'(0.55mg/L). However Fluorine in the other 23 mineral waters were not detectable.

• Journal of Energy Engineering
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• v.27 no.1
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• pp.21-32
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• 2018

In this paper, we reported the current technologies of water scaling removal and also water recovery from the flue gases, which are funded by Department of Energy (DOE), USA. Globally, water resources are limited due to the climate change. The potential impacts of climate change is food and water shortages. In the $21^{st}$ century, water shortages and pollution are expected to become more acute as populations grow and concentrate in cities. At present, the water stress increases over 62.0 ~ 75.8% of total water basin area and decreases over 19.7 ~ 29.0%. Many renewable energy sources demand secure water resources. Water is critical for successful climate change mitigation, as many efforts to reduce greenhouse gas emissions depend on reliable access to water resources. Water hardness is one of the major challenge to coal power plants. Department of energy (DOE) funded and encouraged for the development of advanced technologies for the removal of hardness of water (scaling) and also water recovery from the flue gases from coal power plants.