• Korean Journal of Mineralogy and Petrology
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• v.35 no.2
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• pp.111-123
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• 2022

Carbonate green rust (CGR) and sulfate green rust (SGR) commonly occur in nature. In this study, CGR and SGR were synthesized through co-precipitation, and their formation mechanisms and physicochemical properties were investigated. X-ray diffraction (XRD) and Rietveld refinement showed both CGR and SGR with layered double hydroxide structure were successfully synthesized without any secondary phases under each synthetic condition. Refined structural parameters (unit cell) for two green rusts were a (=b) = 3.17 Å and c = 22.52 Å for CGR and a (=b) = 5.50 Å and c = 10.97 Å for SGR with the crystallite size 57.8 nm in diameter from (003) reflection and 40.1 nm from (001) reflections, respectively. Scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) results showed that both CGR and SGR had typical hexagonal plate-like crystal morphologies but their chemical composition is different in the content of C and S. In addition, Fourier transform infrared (FT-IR) spectroscopy analysis revealed that carbonate (CO₃^2-) and sulfate (SO₄^2-) molecules were occupied as interlayer anions of CGR and SGR, respectively. These SEM/EDS and FT-IR results were in good agreement with XRD results. Changes in the solution chemistry (i.e., pH, Eh and residual iron concentrations (Fe(II):Fe(III)) of the mixed solution) were observed as a function of the injection time of hydroxyl ion (OH^-) into the iron solution. Three different stages were observed in the formation of both CGR and SGR; precursor, intermediator, and green rust in the formation of both CGR and SGR. This study provides co-precipitation methods for CGR and SGR in a way of the stable synthesis. In addition, our findings for the formation mechanisms of the two green rusts and their physicochemical properties will provide crucial information with researches and industrials in utilizing green rust.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.529-532
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• 2001

In this paper, rust-protection performance of concrete using ground granulated blast-furnace slag are discussed. 4 kinds of W/B in combination with 3 kinds of replacement ratio of ground granulated blast-furnace slag and 2 kinds of chloride ion contents of are selected as experimental parameters. According to the experimental results, as the replacement ratio of ground granulated blast-furnace slag is increased, the corrosion area of steel bar tends to be decreased. However, as the autoclave cycle and chloride ion contents are increased, the corrosion area of steel bar is increased. In conclusion, when the replacement ratio of ground granulated blast-furnace slag is 50%, the strength and rust-protection performance appear to be most excellent.

• Journal of Industrial Technology
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• v.22 no.B
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• pp.13-20
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• 2002

The purpose of this study is to investigate the effect of acid fog on the rust formation behavior of weathering steel (SMA50) which is used in uncoated bridges. Weathering steel didn't form the passive film under the environment of acid fog(pH5,6), whereas the environment of distilled water formed the protective oxide film. Therefore, the construction of weathering steel under the environment extremely exposed to SOx and NOx which are the main compositions of acid fog is not adequate. Fatigue limits of weathering steel under acid fog environment are remarkably decreased as compared with environment of distilled water. The corrosive constituents in acid fog has piled up the corrosion products on specimen surface and generated the corrosion pits. Because of the high stress concentration arising at this corrosion pit, relatively low fatigue limits were obtained for acid fog specimens.

• Journal of the Korea Concrete Institute
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• v.12 no.5
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• pp.69-80
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• 2000

This paper presents the prediction of remaining service life of the concrete due to steel corrosion caused by the following three cases; carbonation, using sea sand and using deicing salts. The assessment of initiation period was generalized considering the existing perdiction models in the literature, corrosion experiment and field assessment. To evaluate the prediction equation of rust growth, the corrosion accelerating experiments was performed. The polarization resistance was measured by potentiostat and the conversion coefficient of polarzation resistance to corrosion rate was determined by the measurement of real mass loss. Chloride content, carbonation, cover depth, relative humidity, water-cement ratio(W/C), and the use of deicing salts were taken into account and the resulting prediction equation of rust growth was proposed on the basis of these properties. The proposed equation is to predict the rust growth during any specified period of time and be effective in particular for predicting service life of concrete in the case of using sea sand.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.1
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• pp.13-20
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• 2008

The purpose of this study is to investigate the effect of acid fog on the rust formation behavior of weathering steel (SMA50) which is used in un-coated bridges. Weathering steel didn't form the passive film under the environment of acid fog(pH5,6), whereas the environment of distilled water formed the protective oxide film. Therefore, the construction of weathering steel under the environment extremely exposed to SOx and NOx which are the main compositions of acid fog is not adequate. Fatigue limits of weathering steel under acid fog environment are remarkably decreased as compared with environment of distilled water. The corrosive constituents in acid fog has piled up the corrosion products on specimen surface and generated the corrosion pits. Because of the high stress concentration arising at this corrosion pit, relatively low fatigue limits were obtained for acid fog specimens.

• Transactions of Materials Processing
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• v.21 no.5
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• pp.330-335
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• 2012

Roll formed steel bolts are electrodeposited with Zn-Ni to protect themselves from corrosion. However, white storage stain or white rust(corrosion) is found on Zn-Ni electrodeposited surface of steel bolts when they are exposed to moisture. In this paper a new process is introduced to protect Zn-Ni electrodeposited steel bolt from white storage stain or white rust for a long time under the salt spray test and high humidity test conditions. The better corrosion resistance could be gotten by the additional process of Ni-P electroless deposition and heat treatment to conventional manufacturing method of Zn-Ni coated steel bolt. The corrosion resistance of Zn-Al powder slurry coated steel bolt showed better than that of Zn-Ni electrodeposited one.

• Korean Journal of Plant Resources
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• v.10 no.4
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• pp.360-368
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• 1997

Shepherd's purse (Capsella bursa-pastoris) is one of the minor but important vegetable in Korea. The present study records 4 fungal diseases of this plant occurring under natural condition for the first time in Korea. They are white rust caused by Albugo candida, downy mildew by Peronospora parasitica, leaf spot by Pseudocercosporella capsellae, and powdery mildew by Erysiphe cichoracearum of these, white rust and downy mildew were most common causing severe damages and should be managed for the development of greenhouse cultivation of this plant.

• Korean journal of applied entomology
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• v.26 no.2 s.71
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• pp.113-115
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• 1987

Out of twelve fungicides evaluated in vitro and in vitro to manage rust and leaf spot diseases: Biloxazole was found to control both the diseases simultaneously and also increased the yield of peanut.

• Mycobiology
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• v.43 no.3
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• pp.351-353
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• 2015

Farfugium japonicum is used in traditional medicine and as an edible herb in China and Korea. In July 2013, leaf spots were observed in F. japonicum seedlings at Ulleung Island, Gyeongsangbuk Province, Korea. Early symptoms on the leaf adaxial surface included roughly circular yellow spots that later developed brown, necrotic centers. The aecia were hypophyllous, cupulate, yellowish, $180{\sim}430{\mu}m$ in diameter, clustered, and erumpent with a peridium with a recurved margin. The aeciospores were globoid, $14{\sim}17{\times}13{\sim}16{\mu}m$, light yellow or colorless, and densely verrucose. The 28S rDNA sequence of the isolate was identical to each other and shared 99% identity with Puccinia caricis. This is the first report of rust caused by P. caricis in F. japonicum in Korea or elsewhere in the world.

• Journal of Environmental Science International
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• v.11 no.10
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• pp.1117-1123
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• 2002

Coating ceramic balls activate water molecular in water as radiate far-infrared radiation of high efficiency, and then prevent formation of scale and corrosion of pipe. Therefore, but only keep away drop of heat exchange efficiency of boiler, not also remove formed scale. As a result, pipe of boiler has clean and has form thin protection film in inner of pipe. Also, the water treated by rust preventing system using the ceramic balls, that is harmless, tasteless, odorless, and non-toxicity in the human body, and it can use drinking water. This rust preventing system can save energy and protect environment.