• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.937-942
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• 2004

Physicochemical properties and mineral composition of seaweed salts prepared by incineration and osmotic dehydration methods were determined. As the incineration temperature increased, yield of seaweed salts, insoluble solids, pH, alkalinity, and oxidation-reduction potential (ORP) decreased. Alkalinity of salt prepared with sea tangle was higher than that of sea mustard. ORP decreased by incineration above $700^{\circ}C$, and was lower in salt with sea tangle. As incineration temperature increased, amounts of K and Ca in seaweed salt increased, whereas that of Mg decreased. Potassium and Ca contents of seaweed salt increased remarkably compared with those of common salt. Potassium content of sea tangle salt was higher than that of sea mustard. As incineration time increased, yield of seaweed salts, insoluble solid content, and pH decreased, whereas ORP of the salt increased. Potassium content of seaweed salt with incineration time, while Ca and Na contents decreased after incineration of 8 and 4 hr, respectively. Yield of seaweed salt by osmotic dehydration increased as immersion time in sea water increased. pH of salt from sea mustard was higher than that of sea tangle. ORP of seaweed salt dried three times was -128.8 mV, significantly lower than that of salt prepared by incineration method. As sea water immersion time increased, Mg content of seaweed salt increased significantly, while Ca content decreased. Potassium content of seaweed salt was higher in sea tangle salt. In case of salt prepared by incineration of residuals, pH increased with immersion time but ORP decreased.

• Journal of the Korean institute of surface engineering
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• v.49 no.2
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• pp.141-146
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• 2016

In this study, electrophoretic paint (E-paint) was deposited on the knife-abraded surface of AZ31 magnesium alloy (AZ31), and its adhesion and corrosion resistance were examined by tape peel-test and salt spray test, respectively. E-paint started to deposit on AZ31 Mg alloy after an inductance time and pores were found in the E-paint layer which is ascribed to hydrogen bubbles generated on the surface during the painting process. The pores disappeared after curing for 15 min at $160^{\circ}C$. The E-paint on AZ31 exhibited good adhesion after immersion in deionized water for 500 h at $40^{\circ}C$. The E-paint sample without scratch showed no corrosion after 1500 h of salt spray test. However, on the scratched sample, blisters were visible adjacent to the scratched sites after 500 h of salt spray test.

• Korean Journal of Poultry Science
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• v.24 no.1
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• pp.17-28
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• 1997

This experiment was carried out to investigate the effects of different chilling and packing methods on physico-chernical properties of cold-stored chicken breast and thigh meats. Dehoned chicken breast and thigh meats were chilled either air spray or ice-water immersion method. The chilled meats were either vacuum packed or atmosphere packed, and stored at -2˚C for 1, 3, 7, 11, 15, and 20 days. The pH of both immersion chilled meats and vacuum packed meats were higher than those of their counterparts(P<0.05). The pH of atmosphere packed meats increased as the storage period extended. The moisture contents of vacuum packed meats were remarkably higher than those of atmosphere packed meats. The pH of all treatments decreased as the storage period extended. The shear values of air spray chilled and vacuum packed breast meats were significantly higher than immersion chilled and vacuum packed ones. However, immersion chilled and atmosphere packed breast meats were significantly higher than those of air spray chilled and atmosphere packed breast meats. The shear values of immersion chilled and vacuum packed thigh meats were significantly higher than those of immersion chilled and vacuum packed thigh meats. In atmosphere packed thigh meats, air spray chilling method showed higher shear values than those of immersion chilled thigh meats. In thigh muscle, tenderness values tended to decrease as the storage period extended(P<0.05). Contents of water soluble proteins of vacuum packed and air spray chilled breast and thigh meats were higher than those of their counterparts as the storage period extended(P<0.05). The contents of water soluble proteins significantly decreased as the storage period extended. Salt soluble proteins of atmosphere packed breast and thigh meats were remarkably higher than those of vacuum packed ones(P<0.05). Total lipid contents of atmosphere packed and air spray chilled breast and thigh meats were higher than those of atmosphere packed and immersion chilled meats as the storage period extended. The vacuum packed meats were significantly higher in total lipid contents than those of atmosphere packed meats. The storage period decreased the total lipid contents of cold chicken, Major fatty acids in cold-stored chicken were oleic, palmitic, linoleic and stearic acids, regardless of chilling method. Unsaturated fatty acids of all treatments decreased, but saturated fatty acids increased as the storage period extended.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.247-247
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• 2012

기존형광등보다 에너지소비가 적고, 수명이 길다는 장점을 가진 LED소자는 조명분야뿐만 아니라 선박 및 해양플랜트시장에까지 적용분야가 확대되고 있다. 그러나 LED소자의 수명연장 및 제품신뢰성을 위해서 방열에 관한 연구가 필수적이며 특히, 해양환경적용을 위해서는 내부식성을 요구하는 방열 재료개발에 대한 연구가 필요하다. 일반적으로 방열판소재로 사용되는 알루미늄의 경우 열전도도가 우수하며, 대기 중에서 쉽게 생기는 자연산화막보다 내부식특성을 향상시키기 위해 현재 국내 외의 표면처리 방법으로 전기화학적 방법을 이용한 Anodizing기술을 적용하고 있다. 하지만, Anodizing에 사용되는 질산과 황산액을 처리하는 과정에서 유독물질을 발생시킴으로 유해물질사용제한 등 국제적으로 환경규제가 강화되고 있어 Anodizing기술의 적용이 제한적인 단점이 있다. 본 연구에서는 친환경적 기술인 Plasma Immersion Ion Implantation (PIII)방식을 사용하여 알루미늄표면에 $Al_2O_3$을 형성하였다. 최적의 산화막증착 조건을 찾기 위해 Gas Flow양, Pulse Voltage, 공정온도, 시간 등을 변수로 실험을 진행하였다. SIMS (Secondary ion mass spectroscopy)를 통해 $Al_2O_3$ 박막두께 및 Oxygen의 정량분석을 하였으며, Anodizing처리된 알루미늄시편과 열전도특성과 내부식특성을 비교하기 위해 각각 Hot Disk 열전도율측정기와 Salt water tester chamber를 사용하였다.

• Corrosion Science and Technology
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• v.7 no.1
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• pp.13-15
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• 2008

Aiming at the corrosion circumstances and corrosion prevention needs of downhole oil tubes, series protective coatings for downhole oil tubes have been developed in the authors' laboratory, including a baked type coating YG-01 and an air curing type coating YG-03, etc. The performance investigation of the coatings has been done for testing their corrosion resistance, mainly including salt fog test, immersion test in oil-field waste water and various acid solutions, high temperature and high pressure test in alkali solution or $H_2S/CO_2$ environment, as well as some other performances. The investigation results show that oil tube anti-corrosion coatings developed here can endure over 4000 hrs salt fog test, over 1000 hrs immersion in various acid solutions at room temperature and in boiling oil-field waste water. In addition, the coatings can keep intact after experiencing test in alkali solution under 70 MPa pressure at $150^{\circ}C$ for 24 hrs, and in simulative sour gas environment under the total pressure of 32 MPa ($P_{H_{2}S}=3.2MPa$, $P_{CO_{2}}=3.2MPa$) at $90^{\circ}C$ for 168 hrs, which show that the coatings can be used for corrosion prevention in downhole environments with specific high temperature and high pressure, such as sour gas wells. The other testing results show the oil tube protective coatings have excellent comprehensive performance.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.1
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• pp.101-108
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• 2014

This study was conducted in order to compare the biological activities of water extracts and sugar immersion extracts of green pepper (Capsicum annuum L.), purslane (Portulaca oleracea L.) and shiitake (Lentinula edodes (Berk.) Pegler) by measuring total polyphenol and flavonoid contents, antioxidant activities and inhibitory effects on ${\alpha}$-amylase and ${\alpha}$-glucosidase. The contents of total polyphenols and flavonoids were higher in water extracts than in sugar immersion extracts. The anti-oxidative activities of water and sugar immersion extracts were measured using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity assay and reducing power assay. All extracts scavenged radicals in a concentration-dependent manner, and water extracts showed stronger radical scavenging activity and reducing power than sugar immersion extract. However, they all exhibited lower activities than ascorbic acid. Compared to the anti-diabetic drug acarbose, which was used as a positive control, the two types of extracts exhibited low ${\alpha}$-glucosidase inhibitory activities, although the activity of sugar immersion extracts were 2-fold higher than that of water extracts. ${\alpha}$-Amylase inhibitory action was not observed for any of the extracts. Finally, by cytotoxicity test, we confirmed that sugar immersion extracts were safer than water extracts. These results indicate that water extracts and sugar immersion extracts of green pepper, purslane and shiitake have different advantages in terms of their antioxidant and anti-diabetic effects, respectively.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.2
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• pp.283-299
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• 2017

The leakage of tunnel causes the long-term durability of the structures such as concrete lining to deteriorate. The cause of durability degradation can be various substances contained in groundwater such as chloride, sulphate, water, and gas. In this study, a series of test were carried out to determine the watertightness performance and the resistance to salt water of the spray-applied membrane used as non-structural rock support or as a waterproof material for tunnels. As a result, it was found that the penetration of water could occur in a specimen, and the reason was that the internal pores generated by the mixing of the liquid polymer and the powder material and the internal pores were connected by the water pressure. The tensile strength of the test specimens immersed in distilled water and saline water was found to be reduced to less than half of the tensile strength in normal condition. In addition, The elongation was measured to be higher in distilled water than in salt water. However, this result will require further investigation.

• Composites Research
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• v.24 no.4
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• pp.48-54
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• 2011

The effect of moisture contents by salt water on the strength of composite single-lap bonded joints is investigated. The specimens were manufactured in an autoclave by secondary bonding and immersed in the 3.5% salt water of $71^{\circ}C$ for different durations to get various moisture contents; 0, 0.2, 0.5, 1.0, and 2.0%(saturation). A total of 80 joint specimens were tested for 5 different moisture contents and 2 temperature environments. Test results show that while the joint strengths after the saturation of moisture decrease compared to those of dry ones, the strengths of the pre-saturated joint up to 1.0% of moisture content increase in both room and elevated temperature conditions. It is also shown that the strengths of joints tested in elevated temperature are slightly higher than the strength in room temperature by 2-5% until the moisture content reaches 1 %. In contrast, the high temperature strength of the saturated joint is about 5% lower than the room temperature strength.

• Proceedings of the Korean Institute of Building Construction Conference
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• v.y2004m10
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• pp.71-76
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• 2004

This paper investigate that the effect of the concrete containing mineral admixtures(pozzolanic materials such as fly-ash, ground granulated blast-furnace slag, silica fume and meta kaolin) on the resistance properties to chloride ion invasion. The purposed testing procedure was applied to the concrete added mineral admixtures for $3\sim4$ replacement ratios under W/B ratios ranged from 0.40 to 0.55. Specimens were immersed in $3.6\%$ NaCl solution for 330 days, and penetration depth, water soluble chloride contents and acid soluble chloride contents were measured in 28, 91, 182 and 330 days. Then, diffusion coefficient were calculated using total chloride contents. As a results. the kinds of mineral admixture and replacement ratios had a great effect on the resistance property of the concrete to chloride ion invasion compared with the plain concrete. And the optimal replacement ratios of mineral admixture had a limitation for each admixtures. The amount of acid soluble chloride ions and water soluble chloride ions were varied with the kinds of mineral admixtures and the penetration depth from the concrete skin. Chloride diffusion coefficient of each concretes decreased with the time elapsed. and the diffusion coefficients of the concrete immersed salt water for 330 days had a establishment with the compressive strength measured before immersing.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.197-200
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• 2006

The ingress of chloride ions plays a crucial role for service life design of reinforced concrete structures. In view of durability design of concrete structures under marine environment, one of the most essential parameters is the surface chloride content of concrete. However, on the basis of the results of in-situ investigation, this value has been determining in the numerous studies on the durability design of concrete structures. Hence, it is necessary to confirm the range of the surface chloride content in order to establish a unified durability design system of concrete. This study suggests a rational and practical way to calculate the maximum surface chloride content of submerged concrete under marine environment. This approach starts with the calculation of the amount of chloride ingredients in normal sea water. The capillary pore structure is modeled by numerical simulation model HYMOSTRUC and it is assumed to be completely saturated by the salt ingredients of sea water. In order to validate this approach, the total chloride content of the mortar and concrete slim disc specimen was measured after the immersion into the artificial sea water solution. Additionally, the theoretical, the experimental and in-situ investigation results of other researchers are compiled and analyzed. Based on this approach, it will follow to calculate the maximum surface chloride content of concrete at tidal zone, where the environment can be considered as a condition of dry-wetting cycles.