• Magazine of the Korea Concrete Institute
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• v.10 no.6
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• pp.325-333
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• 1998

Under the seawater environment, the reinforced concrete structure is deteriorated due to physical and chemical attacks. The main deterioration mechanism is the chloride corrosion of reinforcing steel. The corrosion inhibitors have been used to protect the rebars from corrosion which are susceptible to chlorides in concrete. However, there is not clear conclusion about corrosion inhibitors yet. In this study, it is made the accelerated experiment with 3 kinds of corrosion inhibitors for various chloride ingresses. It is estimated corrosion inhibitors that inhibitors by Half-Cell Potential, corrosion area ratio and weight loss ratio. It is concluded that inhibitors are not effective to corrosion inhibition for excessive chloride ingress. However, the effect of inhibition is directly proportional ot contents of corrosion inhibitors in some chloride ingress.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.4
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• pp.45-53
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• 2023

In this study, to analyze the correlation of surface chloride and corrosion amount level according to the installation location of steel members exposed to the marine environment, the surface chloride and mean corrosion depth were evaluated by member units for box girder members of the offshore steel bridge and box specimens. The surface chloride was measured monthly using the Bresle method for one year. The corrosion amount was evaluated by converting the weight loss due to corrosion products generated in the monitoring steel plate into mean corrosion depth. As a measurement result of the surface chloride and corrosion amount, relative differences in surface chloride and mean corrosion depth were appeared depending on the shape or installation location of the steel members. Moreover, even if members of the same shape were installed in the same bridge, it was confirmed that the corrosion amount was increased locally and rapidly. The tendency of corrosion amount depending on the surface chloride was evaluated to analyze the correlation between surface chloride and corrosion amount, and the relation equations that can asseses the corrosion amount depending on the surface chloride were analyzed. From the results of the correlation between surface chloride and corrosion amount, it was found that the corrosion amount of the steel member affected by the surface chloride was varied up to about 1.15 times depending on the structural detail.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.355-362
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• 2016

The pipe material is selected according to the physical and chemical properties of the fluid flowing within it. Because the fluid used in fire extinguish systems is water, the various foreign substances dissolved in it cause scale to form on the pipe wall and accelerate the corrosion and aging of the pipe itself. This results in an increase in the friction loss and eventually degrades the efficiency of the pump. The use of CPVC (Chlorinated Poly-Vinyl Chloride) pipes was confirmed to reduce the friction loss compared to conventional steel pipes in the design and construction stages. The friction loss was found to be 76.64MPa with a C-value of 120 for the steel pipe and 50.72 MPa with a C-value of 150 for the CPVC pipe in an actual apartment construction environment. It was confirmed that the friction loss was improved by about 34% when using the CPVC pipe. When the steel and CPVC pipes were employed in the construction, the construction costs were 1,585,158 and 931,842 won, respectively. Therefore, it was shown that the construction cost was reduced by about 41%. We investigated the safety of the fire extinguishing system and the improvement in the economic performance due to the reduction in the total installed capacity by studying practical applications in the field.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.10
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• pp.883-887
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• 2016

This study aims to evaluate the corrosion behavior of a newly developed high-strength steel in marine environments. Metals used in seawater are easily deteriorated because of the presence of corrosive species such as chloride ions in it. Seawater causes much higher corrosion than fresh water. Thus, the corrosion of steel in marine environment has been recognized as a crucial problem in designing structures which cannot be cathodically protected. In this study, the corrosion resistance of a newly developed high-strength steel was evaluated. Four different specimens were tested to confirm the corrosion resistance. The exposure corrosion test was carried out by exposing the specimens to different marine environments such as atmospheric, tidal, splash, and submerged zones for two years. The specimens taken out from each location were cleaned ultrasonically and chemically prior to the evaluation of their corrosion resistance by the weight loss method. Finally, the pitting depth of the specimens was also measured to evaluate their pitting corrosion. The conditions used for the corrosion test were similar to the environmental conditions. The corrosion test results revealed that the corrosion rate and pitting corrosion of the newly developed high-strength steel was lower than that of the other carbon steels.

• Advances in concrete construction
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• v.7 no.2
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• pp.75-85
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• 2019

The present study is focused on the mechanical and durability properties of ternary blended cement concrete mix of different grades 30 MPa, 50 MPa and 70 MPa. Three mineral admixtures (fly ash, silica fume and lime sludge) were used as a partial replacement of cement in the preparation of blended concrete mix. The durability of ternary blended cement concrete mix was studied by exposing it to acids HCl and $H_2SO_4$ at 5% concentration. Acid mass loss factors (AMLF), acid strength loss factor (ASLF) and acid durability factor (ADF) were determined, and the results were compared with the control mix. Chloride ions penetration was investigated by conducting rapid chlorination penetration test and accelerated corrosion penetration test on control mix and ternary blended cement concrete. From the results, it was evident that the usage of these mineral admixtures is having a beneficiary role on the strength as well as durability properties. The results inferred that the utilization of these materials as a partial replacement of cement have significantly enhanced the compressive strength of blended concrete mix in 30 MPa, 50 MPa and 70 MPa by 42.95%, 32.48% and 22.79%. The blended concrete mix shown greater resistance to acid attack compared to control mix concrete. Chloride ion ingress of the blended cement concrete mix was low compared to control mix implying the beneficiary role of mineral admixtures.

• Clinical and Experimental Pediatrics
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• v.53 no.8
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• pp.809-813
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• 2010

Bartter syndrome (BS) is an autosomal recessively inherited rare renal tubular disorder characterized by hypokalemic metabolic alkalosis and hyperreninemic hyperaldosteronism with normal to low blood pressure due to a renal loss of sodium. Genetically, BS is classified into 5 subtypes according to the underlying genetic defects, and BS is clinically categorized into antenatal BS and classical BS according to onset age. BS type I is caused by loss-of-function mutations in the $SLC12A1$ gene and usually manifests as antenatal BS. This report concerns a male patient with compound heterozygous missense mutations on $SLC12A1$ (p.C436Y and p.L560P) and atypical clinical and laboratory features. The patient had low urinary sodium and chloride levels without definite metabolic alkalosis until the age of 32 months, which led to confusion between BS and nephrogenic diabetes insipidus (NDI). In addition, the clinical onset of the patient was far beyond the neonatal period. Genetic study eventually led to the diagnosis of BS type I. The low urinary sodium and chloride concentrations may be caused by secondary NDI, and the later onset may suggest the existence of a genotype-phenotype correlation. In summary, BS type I may have phenotype variability including low urine sodium and chloride levels and later onset. A definitive diagnosis can be confirmed by genetic testing.

• Resources Recycling
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• v.27 no.1
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• pp.38-44
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• 2018

A large amount of Nd-Fe-B magnet scraps are generated during magnet manufacture process. In this study, selective chlorination of the rare earth elements by hydrogen chloride gas which obtained from the pyrolysis of polyvinyl chloride (PVC) was investigated. In thermogravimetric analysis, drastic weight loss was occurred at about 500 K and 710 K. At the isothermal experiments, the weight loss reaches about 30% above 673 K. XRD patterns characterized that after each experiments, ${\alpha}$-Fe, Nd oxychloride, Nd chloride, and Fe chlorides were formed, and the leaching residues remain only ${\alpha}$-Fe. The yields of Nd, Dy, and Fe for the isothermal experiment were increased with temperature and peaked at 873 K. As PVC ratio increased, the yields of Nd, Dy and Fe were also increased.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.23 no.2
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• pp.1-12
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• 2010

Objective : For this study, mice on mercurial toxication were given mercuric subcutaneous injection to their abdomen factitiously. After delivering Kami- bangpungtongseong-san(KBT) extracts to the mice by oral administration, we observed changes from liver and kidney of mice. Method : The BALB/c mice were distributed into three groups: No treated group(Normal group), Mercuric chloride subcutaneous injection group(Control group), Kami-bangpungtongseong-san-treated group (Sample group). KBT Extracts were delivered orally in 7 days. We observed involution of liver, necrosis of liver and cell plate loss of liver, lipid peroxidation CYP1A1 expression. We observed involution of proximal convoluted tubules, hypertrophy of Bowman's capsule, periodic acid-Schiff(PAS)'s positive reaction of proximal convoluted tubules, heat shock protein(HSP)700's positive reaction in glomerulus. For the charting the results, image analysis was taken. The result of image analysis was verified significance by Sigmaplot 2000(P<0.05). Result : The mice' liver on mercurial toxication were relieved involution of liver, necrosis of liver, and cell plate loss of liver and also declined lipid peroxidation and CYP1A1 expression. The mice' kidney on mercurial toxication were relieved involution of proximal convoluted tubules, hypertrophy of Bowman's capsule and increasing PAS's positive reaction of proximal convoluted tubules. On the other hand it was declined HSP700's positive reaction in glomerulus. Conclusion : According to the result of study, we think that we can expect to the effect of KBT extracts' therapeutic action to tissue injuries of the mice' liver and kidney on acute mercurial toxication.

• Food Science of Animal Resources
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• v.31 no.3
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• pp.389-397
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• 2011

This study was conducted to examine the effect of salt concentration in soybean sauce (ganjang) on pre-rigor ground Hanwoo (Korean native cattle) muscle. Although adding soybean sauce reduced pH of pre-rigor Hanwoo muscle, it improved the water holding capacity (WHC), cooking loss, total protein solubility, myofibrillar fragmentation index (MFI), 2-thiobar-bituric acid (TBA) values, and textural properties by increasing salt concentration in the soybean sauce. In particular, adding soybean sauce inhibited lipid oxidation despite increasing salt concentration. An increased salt concentration in the soybean sauce in pre-rigor Hanwoo muscle tended to make the meat have lower lightness and higher redness and yellowness values. Although soybean sauce had a significantly lower pre-rigor salting effect than sodium chloride in terms of cooking loss and total protein solubility (p<0.05), soybean sauce improved myofibrillar fragmentation and lipid oxidation when compared with sodium chloride. Furthermore, no significant differences in textural properties were observed between adding soybean sauce and sodium chloride at the same salt concentrations. Therefore, soybean sauce can be a functional curing material for pre-rigor muscle.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.3
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• pp.115-122
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• 2006

Ten types of steel bars having different Cr contents were embedded in concretes with chloride ion contents of 0.3, 0.6, 1.2, and $2.4kg/m^3$ to fabricate specimens assuming such deteriorative environments. After being carbonated to the reinforcement level, these concretes were subjected to corrosion-accelerating cycles of heating/cooling and drying/wetting. The time-related changes in the corrosion area and corrosion loss of the Cr-bearing rebars were then measured to investigate their corrosion resistance. The results revealed that in a deteriorative environment prone to both carbonation and chloride attack, corrosion resistance was evident with a Cr content of 7% or more and 9% or more in concretes with chloride ion contents of 1.2 and $2.4kg/m^3$, respectively.