• Korean Journal of Materials Research
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• v.23 no.9
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• pp.495-500
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• 2013

Mo-based thin films are frequently used as back electrode materials because of their low resistivity and high crystallinity in CIGS chalcopyrite solar cells. Mo:Na/Mo bilayer thin films with $1{\mu}m$ thickness were deposited on soda lime glass by varying the thickness of each layer using dc-magnetron sputtering. The effects of the Mo:Na layer on morphology and electrical property in terms of resistivity were systematically investigated. The resistivity increased from $159{\mu}{\Omega}cm$ to $944{\mu}{\Omega}cm$; this seemed to be caused by increased surface defects and low crystallinity as the thickness of Mo:Na layer increased from 100 nm to 500 nm. The surface morphologies of the Mo thin films changed from a somewhat coarse fibrous structures to irregular and fine celled structures with increased surface cracks along the cell boundaries as the thickness of Mo:Na layer increased. Na contents varied drastically from 0.03 % to 0.52 % according to the variation of Mo:Na layer thickness. The change in Na content may be ascribed to changes in surface morphology and crystallinity of the thin films.

• Journal of the Korean Ceramic Society
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• v.33 no.2
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• pp.242-250
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• 1996

Glasses of Na2O-Al2O3-SiO2 system were prepared and ion-exchange characteristics change of properties and bactericidal effects by Na+↔Ag+ ion exchange were studied. Parent glasses with three compositions of varying Na2O in the 20~30 wt% were ion-exchanged in the molten salt of 2 mol% AgNO3+98 mol% NaNO3 at 320~36$0^{\circ}C$ for 15~16min. Amount of ion exchange and penetration depth of Ag+ ion increased with Na2O content in the parent glass ion exchange temperature and time. After ion exchange densities and Vickers hardness of the glasses increased and the glasses showed yellow-brown color and as amount of ion exchange increased the color turned deep because partial reduction and agglomeration of Ag+ into Ag0 results in absorption of visible light. After ion exchange chemical durability of the glass to wter was enhanced compara-bly that weight loss and change of surface of the glass were not found for the leaching test in 5$0^{\circ}C$ K.I water for 240hrs. Bactericidal effect of ion exchanged glass on Staphylococcus aureus and E. coli was determined by microorganism test and bactericidal effect increased with amount of ion exchange and incubation time.

• Economic and Environmental Geology
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• v.55 no.6
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• pp.671-687
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• 2022

It has been reported that about 47% of groundwater wells within 10 km from the coastline in the western/southern coastal areas of Korea were affected by seawater. It has been interpreted that the cause of groundwater salinization is seawater intrusion. The Gilsan stream in the Seocheon area was a tidal stream until the Geumgang estuary dam was constructed and operated. Therefore, it is likely that the Gilsan stream catchment was deposited with sediments containing high-saline formation water prior to the use of landfill farmland at this catchment area. The groundwater in this study area showed EC values ranging from 111 to 21,000 µS/cm, and the water quality types were diverse including Ca(or Na)-HCO₃, Ca(or Na)-HCO₃(Cl), Na-Cl(HCO₃), Na-Cl types. It is believed that this diversity of water quality is due to the mixing of seawater and fresh groundwater generated by infiltration of precipitation and surface water through soil and weathered part. In this study, we discussed whether this water quality diversity and the presence of saline groundwater are due to present seawater intrusion or to remnant high-saline pore water in sediments during flushing out process. For this, rain water, surface water, seawater, and groundwater were compared regarding the water quality characteristics, tritium content, oxygen/hydrogen stable isotopic composition, and ⁸⁷Sr/⁸⁶Sr ratio. The oxygen/hydrogen stable isotopic compositions indicated that water composition of saline groundwaters with large EC values are composed of a mixture of those of fresh groundwater and surface water. Also, the young groundwater estimated by tritium content has generally higher NO₃ content. All these characteristics showed that fresh groundwater and surface water have continued to affect the high-saline groundwater quality in the study area. In addition, considering the deviation pattern in the diagrams of Na/Cl ratio versus Cl content and SAR (sodium adsorption ratio) versus Cl content, in which two end members of fresh surface-ground water and seawater are assumed, it is interpreted that the groundwater in the study area is not experiencing present seawater intrusion, but flush out and retreating from ancient saline formation water.

• Journal of Food Hygiene and Safety
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• v.6 no.3
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• pp.139-145
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• 1991

In order to observe the Na contents, Korean common foods, especially processed foods were analyzed by Atomic Absorption Spectrophotometer. 1. The Na contents of instant noodle (ramen) was 400-900 mg/100 g and Na contents of their soup powder was 10000-16000 mg/100 g. 2. The Na contents of corns and beans was very low but their processed foods, com Dake and soybean milk, had relatively high Na contents. 3. The Na contents of meats was 40-60 mg/100 g but the Na contents of meats products was 700-900 mg/100 g. 4. The Na contents of Davoring salt was 12000-38000 mg/100 g, those of soybean products was 3000-6OOO mg/100 g, and that of seasoning MSG was 8000-17000 mg/100 g. 5. There was no statistical difference between the results of wet ash method and dry ash method in the Na contents of all food groups.

• Food Science of Animal Resources
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• v.37 no.2
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• pp.210-218
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• 2017

The intake of dietary salt through food now exceeds current nutritional recommendations and is thought to have negative effects on human health, such as the increasing prevalence of hypertension. This study was performed to investigate whether $W_1/O/W_2$ double emulsions can be used to enhance the saltiness of cheese without increasing the salt content ($W_1$ is distilled water or 1% abalone hydrolysate, and $W_2$ is 1% NaCl or 1% abalone hydrolysate + 1% NaCl solution). We also investigated the effect of adding abalone hydrolysate to the double emulsion as a saltiness enhancer. The cheeses were physico-chemically evaluated to determine curd yield, pH value, moisture content, color, texture, salt release rate, and sensory properties. No significant differences were observed in curd yield, pH value, moisture content, lightness, or redness between the cheeses made with and without the double emulsion. However, in the evaluation of salt release rate, fresh cheese made with double emulsion ($W_1$ = distilled water, $W_2$ = 1% NaCl + 1% abalone hydrolysate) was detected earlier than the control or the other treatments. In the sensory evaluation, fresh cheese made with the double emulsion showed higher scores for saltiness and overall preference than the control or the other treatments. We concluded that abalone hydrolysate encapsulated in a double emulsion ($W_1$ is water and $W_2$ is abalone hydrolysate and NaCl solution) could enhance the saltiness of fresh cheese while maintaining the same salt concentration, without altering its physical properties.

• Journal of the Korean Society of Food Culture
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• v.28 no.3
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• pp.293-302
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• 2013

We investigated treatments for the browning prevention of black carrot extracts and determined the characteristics and qualities of jelly supplemented with black carrot extract. Ascorbic acid, citric acid, and NaCl were added to black carrot extract and changes in color, texture, and anthocyanin content were evaluated. Changes were also determined and a sensory evaluation was performed for jelly supplemented with black carrot extract. The addition of 0.15 and 0.20% ascorbic acid prevented the browning of black carrot extracts and decreased anthocyanin content during the storage period. However, citric acid did not have a preventative effect, despite decreasing the pH below 5.0. Similar to results on the extract, 0.15% ascorbic acid maintained a reddish-violet color in jelly supplemented with black carrot extract by lowering browning during the storage period. Jelly supplemented with 0.15% ascorbic acid had an increased elasticity, gumminess, and chewiness, but jelly supplemented with 0.15% ascorbic acid+0.05% NaCl had a lowered hardness compared with the control during the storage period. In a sensory evaluation, the overall preference, in descending order, was: 0.15% ascorbic acid+0.05% NaCl > 0.15% ascorbic acid > control. In conclusion, 0.15~0.20% ascorbic acid prevented the browning of black carrot extract and inhibited a decrease in anthocyanin content. Jelly supplemented with black carrot extract and 0.15% ascorbic acid+0.05% NaCl were optimal for producing a soft jelly texture.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.1
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• pp.118-125
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• 1999

Effects of adding of Angelica keiskei Koidz flour on the quality characteristics of bread were inves tigated. The content of total dietary fiber was 31.89% in flour of Angelica keiskei Koidz leaf and 43.37 % in that of stem. The content of insoluble dietary fiber increased by blanching, but those of soluble dietary fiber and insoluble dietary fiber increased by steeping in NaCl solution. In the results of sensory evaluation of Angelica keiskei Koidz flour, leaf steeped in NaCl solution and blanched stem showed good overall preference. With the addition of Angelica keiskei Koidz flour, water binding capacity and loaf weight increased, while the loaf volume decreased. The loaf volume of bread added with leaf steeped in NaCl solution and blanched stem were higher than those added with natural Angelica keiskei Koidz flour. The lightness and redness values decreased with the increase of Angelica keiskei Koidz flour content in bread but yellowness values increased. In the texture analyzer measurement for bread added with Angelica keiskei Koidz flour, hardness and springiness somewhat increased, while cohesiveness, gumminess and chewiness decreased. As the results of sensory evaluation of bread added with Angelica keiskei Koidz flour, the score of the breads added with 5% leaf steeped in NaCl solution and 5%, 10% blanched stem were somewhat lower than those of control bread. In terms of rate of addition of Angelica keiskei Koidz flour, the bread added with leaf at 5% level, natural stem at 5% level and stem by blanching at 5%, 10% level had good overall preference.

• Korean Journal of Agricultural Science
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• v.43 no.3
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• pp.360-368
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• 2016

A more efficient use of nutrients can benefit both farmers and water quality. To propose an establishment scheme for official standards for liquid fertilizer from swine manure slurry, we evaluated previous and present data related to swine manure as well as analyzed 101 swine manure samples collected from 28 public livestock recycling centers throughout the nation. From these investigations, we found that the official standards for byproduct fertilizers set by the Rural Development Administration (RDA), especially for a liquid swine manure fertilizer, should be revised due to nutrient content requirements having to meet at least 0.3% content for the sum of nitrogen, phosphorus, and potassium. Otherwise, most of the swine manure cannot be utilized as a liquid fertilizer because the result of the 101 samples' analysis showed fewer than 28% of them met the minimum standard of ${\geq}0.3%$ content for the sum of nitrogen, phosphorus, and potassium, while the contents of heavy metals as indicators of toxicity met the standard requirements. Therefore, it is suggested that official standards for byproduct fertilizers set by RDA should be revised as follows: no limit for nutrient contents and addition of chloride as homogeneity. Also, NaCl should be changed to Na because NaCl cannot be analyzed by instrument.

• Korean Journal of Microbiology
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• v.38 no.3
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• pp.168-172
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• 2002

Budding yeasts maintain an effective system to regulate intracellular pH in response to environmental pH fluctuation. In a previous study we reported that SHC1 plays a role in cell growth at alkaline condition, not at acid pH. We constructed a null mutant deleted an entire open reading frame for SHC1. To test whether the retardation in cell growth was caused by the absence of intracellular pH buffering capacity, we measured intracellular pH with a pH-sensitive fluorescent dye, C.SNARE. The intracellular pH of the mutant cell was much higher than that of wild-type cells, indicating that the mutant cells lack some types of buffering capacity. We also investigated the level of $Na^＋ and K^＋$ content with atomic mass spectroscopy after alkali shock. Wild-type cell showed a higher level of intracellular K^＋$ content, whereas there was no difference in $Na^＋$ level. The result suggested that K^＋$ is more important in the regulation of intracellular pH in yeasts.

• Advances in concrete construction
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• v.14 no.1
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• pp.1-13
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• 2022

Due to the physical-chemical characteristics of some bottom ash (BA), there are technical, economic and environmental limitations to find a destination that will add value to it. In Brazil, this residue is eventually used for filling coal extraction pits or remains in sedimentation ponds, creating a susceptible panorama to environmental issues. The geopolymers binders are one of the alternatives to the proper use high amounts of these materials. In this work, geopolymeric binder pastes were produced with BA mixed to activators with different alkali contents (expressed as %Na₂O), as well as the incorporation of soluble silicates (Ms content). The production of binary geopolymeric pastes based on the use of two industrial wastes: fluid catalytic cracking (FCC) and aluminum anodizing sludge (AAS), was also assessed. The content in mass of BA/FCC and BA/AAS ranged from 100/0, 90/10; 80/20 and 70/30. Systems with soluble silicates as activator in a molar ratio SiO₂/Na₂O of 1.0 (Ms = 1.0) and Na₂O content of 15%, showed the best results of mechanical strength (42 MPa at day 28^th). The improvement is up to 5X when compared to NaOH based systems. For systems with partial replacement of BA of 10% of AAS and 20% of FCC (80/20), the presence of soluble silicates was also effective to increase compressive strength.