• Proceedings of the KAIS Fall Conference
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• 2011.05a
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• pp.510-512
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• 2011

본 연구에서는 수지상 아연 생성 반응에 영향을 주는 인자로써 산화아연의 농도에 주목하여, 아연의 전기화학적 산화 환원 반응에 미치는 전해질 농도의 영향을 규명하는 것을 목적으로 하였다. 아연의 석출 용해 반응은 산화아연의 전해질 농도에 크게 영향을 받았다. 저농도에서는 사이클이 진행될수록 충 방전 효율이 크게 저하되는데 비해, 고농도에서는 상대적으로 고효율이 유지되었다. 또한 각 농도의 용액에서 50 사이클이 진행된 후 생성된 수지상 아연은 저농도에서 생성된 수지상 아연보다 고농도에서의 수지상 아연이 두꺼운 것을 확인하였다.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.4
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• pp.228-233
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• 2015

This study was performed to examine the effect of zinc on the biodegradability, nitrification, denitrification and oxygen uptake rate (OUR) using batch reactor and continuous flow stirred tank reactor (CSTR) of anaerobic/anoxic/oxic ($A^2/O$). The results of this study can be summarized as follows. In the case of the effect of zinc on organic treatment, zinc had no effect up to 12 mg/L with batch reactor but biodegradability was lowered when it was above 3.0 mg/L with CSTR. Concerning the case on nitrification and removal of nitrogen, nitrification rate was lowered when zinc was above 6.0 mg/L with batch reactor and removal rate of nitrogen was lowered when zinc was above 3.0 mg/L with CSTR. Removal rate of phosphorus was lowered when it was above 6.0 mg/L zinc with batch reactor and above 3.0 mg/L zinc with CSTR. In the case of OUR, it decreased as microbial activity was affected when zinc concentration was above 3.0 mg/L in CSTR.

• Journal of Oral Medicine and Pain
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• v.32 no.3
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• pp.273-281
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• 2007

Zinc compounds have been used in various fields - cosmetics, medicine, and dentistry -because of its effective functions to human tissues or organs. Especially, it is well known that zinc has many biologic effects in oral cavity. Zinc ion can affect various oral microorganisms, resulting in reduction of oral bacteria, dental plaque, and dental caries. Also, zinc ion has an ability to reduce amounts of oral anaerobic bacteria and oral VSC and can reduce oral malodor. The author summarized the characteristics and toxicity of zinc, several forms of zinc compounds applied in human tissues, and reviewed biologic effects of Zinc in oral cavity (anti-bacterial effects, anti-plaque effects, anti-caries effects, and anti-VSC effects of zinc). Because of many advantages of zinc in oral cavity, it can be concluded that application of zinc compound to various oral diseases will be extended and activated, and promising.

• Journal of the East Asian Society of Dietary Life
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• v.9 no.1
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• pp.17-26
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• 1999

This study was conducted to investigate the effect of Zn and Fe levels on lipid metabolism and micromineral contents in high fat diet-induced obese rats. Male sprague-dawley rats weighing approximately 100g were fed a normal or high fat diet. After 10 weeks high fat diet, rats were fed different levels of Zn and Fe. Serum triacyglycerol and HDL-cholesterol were affected to Zn and Fe levels in normal group. The micromineral (Zn, Fe, Cu, Mn) contents in liver were significantly different in high fat diet group by Zn intake levels and in normal diet group by Fe intake levels. However, micromineral contents in kidneys were not affected to different levels of Fe in both obese and normal rats. There were no differences in spleens of obese rats fed high fat diet according to Zn and Fe intake levels. But in normal group, Mn content of spleen were exclusively affected to Zn levels.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.25 no.3
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• pp.67-80
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• 2020

Zinc (Zn) is known as an essential micronutrient for phytoplankton in the ocean. In surface waters, most of total dissolved Zn presents as organic complexes, and organic complexation dominates the speciation of Zn in seawater. Organic complexation reduces the bioavailable fraction of Zn, the free metal ion (Zn²⁺), which present less than 5% in surface waters. In this paper, a brief introduction on chemical speciation of dissolved Zn in seawater and analytical method for chemical speciation measurement is provided. Some representative studies were also introduced to describe the importance of chemical speciation of Zn (or other trace metals) on bioavailability and biogeochemistry in the ocean.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.132-132
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• 2012

아연-마그네슘 합금은 기존의 대표적 강판 코팅 소재인 아연보다 뛰어난 내식성으로 인해 차세대 강판 코팅 소재로서 주목받고 있다. 그러나 이러한 아연-마그네슘 합금을 아연의 대체 소재로 사용하기 위해서는 내식성 이외에도 사용 환경에 적합한 일정 수준 이상의 기계적 특성이 반드시 필요하다. 따라서 본 연구에서는 마그네슘 함량을 달리하여 아연-마그네슘 합금을 제조하였으며, 이를 대상으로 경도, 압축강도 등의 특성 평가를 실시하여, 아연-마그네슘 합금의 기계적 특성에 미치는 금속간화합물의 영향을 분석하였다.

• Journal of the Korea Concrete Institute
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• v.26 no.3
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• pp.299-306
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• 2014

Coating is one of the methods used to solve the problem of corrosion of reinforcement in concrete structures. There are few research reported in the literature regarding the effect of zinc-coating on flexural behavior compared to epoxy coating. The objective of this study was to determine whether zinc-coated rebar adversely affects flexural behavior. Concrete beams reinforced with black or zinc-coated steel were tested in flexure. The test variables included the presence of rebar surface coating with zinc, steel ratio used and cover depth. The study concentrated on comparing crack pattern, crack width, deflection and strain. The ultimate flexural capacity of beams reinforced with zinc-coated bars was not different from that of black steel reinforced beams. The results from deflection and crack width measurements were indicative of no significant variation for the different rebar surface conditions. In addition, it was found that load-strain curve of beam reinforced with zinc-coated steel was similar to that of beam reinforced with zinc-coated steel. Therefore, the test results indicated that the use of zinc-coated rebar had no adverse effect on flexural behavior compared to the use of black rebar.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.34 no.4
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• pp.117-124
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• 2024

Zinc oxide nanoparticles were synthesized using the polyol method with ethylene glycol containing hydroxyl groups (-OH). It was confirmed that the zinc compounds prepared by the polyol method were a mixture of zinc carbonate hydroxide (Zn₅(OH)₆(CO₃)₂) and zinc oxide (ZnO) crystalline structures. Calcination at 400℃, 600℃ and 800℃ was performed to examine the effects of calcination temperature on the particle size, morphology and crystallinity of zinc oxide. ZnO powders of calcination at 800 ℃ was evaluated to particle size analysis from ethylene glycol containing precursor solution compared with distilled water based solution. The zinc oxide particles obtained from the former had a particle size of approximately 404 ± 51 nm, whereas those from the latter exhibited a more uniform nanoparticles morphology with a particle size of approximately 109 ± 29 nm. This demonstrates that the addition of ethylene glycol can control the influence of water molecules, enabling the direct synthesis of zinc oxide in the form of uniform nanoparticles.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.4
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• pp.136-143
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• 2015

Galvanizing is one of the method used to solve the problem of corrosion of reinforcement in concrete structures. There few research reported in the literature regarding the effect of galvanized coating on the behavior of lap splices in concrete beams. The objective of this study was to determine whether galvanized rebar adversely affects lap splice behavior and bond strength. Concrete beams reinforced with black or galvanized rebar were tested in flexure. The test variables included the presence of galvanized rebar steel diameter, and lengths of lap splices. The study concentrated on comparing crack, failure pattern, and bond strength. The ultimate behavior of beams reinforced with galvanized rebar was not significantly different from that of black steel reinforced beams. Therefore, the test results indicated that the use of galvanizing-coated rebar had no adverse effect on behavior in lap splices of rebar compared to the use of black rebar.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.7
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• pp.418-425
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• 2017

ZnO nanoparticles (ZnO NPs) are mainly used in semiconductors, solar cells, biosensors, and cosmetics (sunscreen). In this study, we investigated the behavior of ZnO NPs in aquatic and soil environments and their effects on plants (Artemisia annua L.) in hydroponic cultivation. It was confirmed that the ZnO NPs size increased and their dissolution decreased with increasing in pH. Leaching distance of ZnO NPs was less than 2.5 cm, indicating that ZnO NPs had a little potential to leach into deeper soil layers. When ZnO NPs were exposed to plant, the total weights of plants decreased. The effects on the length of root and shoot were not observed. In addition large amount of ZnO NPs were adsorbed on the surface of plant root and didn't translocate into shoot. These results suggest that ZnO NPs block the pores of the root cell wall and decrease the bioavailability of plant nutrients. Therefore it can be speculated that the particles increase in size and settle down in the water environment and may adversely affect the plant growth by firmly adhering to the root surface when the ZnO NPs are exposed to the environment.