• Proceedings of the Korean Reliability Society Conference
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• 2005.06a
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• pp.349-355
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• 2005

The bolts used for the electronic parts of a car a is the important parts which carry out an electric and physical performance. At the time of storage, transportation and use, Corrosion occurs in bolts under the influence of environmental factor. During the period exported especially overseas the chemical corrosion by the chlorine ion contained in the atmosphere occurs frequency. Then, The failure mechanism over corrosion is investigated and we consider to the design procedure of a environmental examination. We are going to select the proper plating thickness of bolts through a salt spray test, for investigating the corrosion resistance of bolts.

• Journal of Plant Biotechnology
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• v.49 no.2
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• pp.107-117
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• 2022

Increasing soil salinity is one of the global challenges that the agriculture sector in Egypt has been facing; 33% of the cultivated land in Egypt, which includes merely 3% of the entire land area, is already salinized. The present review sheds light on the role of fungal biopriming, a technique in which hydrated seeds are inoculated with beneficial fungal flora, in mitigating the deleterious influence of NaCl tension. Endophytic fungi were recognized to be able to interact with several plant species, markedly contributing to the mitigation of NaCl stress in these plants, such that some plants get impoverished to their absent associated microbes under stressful conditions.

• Proceedings of the SCSK Conference
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• 1999.10a
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• pp.65-74
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• 1999

We have studied the stability of W/O high internal phase emulsions(HIPE) containing water, cetyl dimethicone copolyol and oils varying magnesium sulfate in the range 0 to 0.5wt% and oil polarities, respectively. The rheological consistency was mainly destroyed by the coalescence of the deformed water droplets. The greater the increase of concentrated modulus was, the less coalescence occurred and the more consistent the concentrated emulsions were. The increasing pattern of complex modulus versus volume fraction has been explained with the resistance to coalescence of the deformed interfacial film of water droplets in concentrated W/O emulsion. The stability is dependent on: (i) the choice of the oil is important, the requirements coincide with the requirements for the formation of the rigid liquid crystalline phases :5; and (ii) addition of salts the aqueous phase opposes the instability due to coalescence:. Increasing the salt concentration increases the refractive index of the aqueous phase. It lowers the difference in the refractive index between the oil and aqueous phases. This decreases the attraction between the water domains, thus increasing the stability.

• Journal of Microbiology and Biotechnology
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• v.3 no.1
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• pp.24-30
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• 1993

In order to develop a novel yeast which produces the charateristic aroma of soy sauce, a protoplast fusion between Zygosaccharomyces rouxii WFS4 and Torulopsis versatilis IAM 4993 was carried out. Auxotrophic mutants as selective markers were obtained from Zygosaccharomyces rouxii and Torulopsis versatilis by treatment of N-methyl-N -nitro-N-nitrosoguanidine. The conditions of the protoplast formation and the regeneration for fusion were examined. The protoplast fusion using polyethylene glycol 4000 led to the fusion frequency of $4~5{\times}10^{-7}\;cells/ml$. Among fusants, a fusant ST723-F31 presented the best results in terms of the aromaticity of fragrance, the growth pattern, the resistance against salt and the degree of growth according to pH. It makes easy to control the production and the balance of aroma components so that it gives a good flavor, shortens the fermentation period and, simplifies the preparation process when using a bioreactor into which fusant is immobilized.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.115-116
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• 2022

Large concrete mass members are commonly used as matte bases for skyscrapers. In general, Integral casting is preferred to secure construction convenience and durability quality rather than separate casting. However, there is a possibility that cracks may occur in the early stages due to the generation of a lot of hydration heat, and thus durability will decrease, so it is necessary to determine an appropriate mixture and verify it through experiments. The purpose of the study was to conduct a review on the durability of the optimal high-performance low-heating concrete combination derived through the experiment and to conduct a review analysis on the performance satisfaction and performance expression mechanism.

• Journal of the Korea Concrete Institute
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• v.19 no.6
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• pp.701-706
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• 2007

This study evaluated the durability of high-performance shotcrete mixed in the proper proportions using alkali-free and cement mineral accelerators as a permanent support that maintains its strength for the long term. Durability tests were performed the chloride permeability, repeated freezing and thawing, accelerated carbonation, and the effects of salt environments. Test results showed that all the shotcrete mixes included silica fume had low permeability. In addition, after 300 freeze/thaw cycles, the shotcrete mix had excellent freeze/thaw resistance more than the 85% relative dynamic modulus of elasticity. The accelerated carbonation test results were no effect of accelerator type but, the depth of carbonation was greater in the shotcrete mix containing silica fume. No damage was seen in a salt environments. Therefore, the high performance shotcrete mix proportions used in this study showed excellent durability.

• Polymer(Korea)
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• v.31 no.4
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• pp.302-307
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• 2007

The resistive-type humidity sensors were prepared from the copolymers of [2-[(methacryloyloxy)ethyl]dimethyl]propylamonium bromide (MEPAB), [2-[(methacryloyloxy)ethyl]-2-hydroxyethyl]dimethylammonium bromide (MEHDAB), 2- [(methacryloyloxy)ethyl]trimethylammonium chloride (METAC), and n-butyl methylacrylate (MBA). Four component copolymers MEPAB/BMA/MEHDAB/METAC=4/4/1/1, 3/5/1/1, 2/6/1/1, 1/7/1/1 crosslinked with blocked-isocyanate on Ag/Pd electrode/alumina substrate showed a good durability at high humidities. The various electrical properties such as frequency dependency, temperature dependency, hysteresis, response time and water durability were examined. In the case of copolymer composed of MEPAB/BMA/MEHDAB/METAC=2/6/1/1, the resistance varied from $1.4\;M{\Omega}$ to $2.9\;k{\Omega}$ at $25^{\circ}C$ in the range of $30{\sim}90\;%RH$ and this copolymers showed a good linearity and low hysteresis.

• Clinical and Experimental Pediatrics
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• v.54 no.2
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• pp.90-93
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• 2011

Pseudohypoaldosteronism type 1 (PHA1) is a rare form of mineralocorticoid resistance characterized in newborns by salt wasting with dehydration, hyperkalemia and failure to thrive. This disease is heterogeneous in etiology and includes autosomal dominant PHA1 owing to mutations of the NR3C2 gene encoding the mineralocorticoid receptor, autosomal recessive PHA1 due to mutations of the epithelial sodium channel (ENaC) gene, and secondary PHA1 associated with urinary tract diseases. Amongst these diseases, autosomal dominant PHA1 shows has manifestations restricted to renal tubules including a mild salt loss during infancy and that shows a gradual improvement with advancing age. Here, we report a neonatal case of PHA1 with a NR3C2 gene mutation (a heterozygous c.2146_2147insG in exon 5), in which the patient showed failure to thrive, hyponatremia, hyperkalemia, and elevated plasma renin and aldosterone levels. This is the first case of pseudohypoaldosteronism type 1 confirmed by genetic analysis in Korea.

• Journal of the Korean Chemical Society
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• v.42 no.6
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• pp.696-702
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• 1998

The effect of alkali metal salt on the activity of Co-Mo catalyst which has high resistance to sulfur poisoning for water gas shift reaction(WGSR) was studied. Two groups of catalysts were prepared to investigate the effects of anion and cation in alkali metal salts. For K-doped catalysts made with various potassium salts having different anion, the catalytic activity was explained to depend mainly on the BET surface area. Among the catalysts prepared by various nitrates of alkali metal as precursor, the Li-doped catalyst showed the best activity, and the others did not make significant differences giving relatively low activities. And the change of BET surface area by varying the loading of alkali metal showed a similar trend to that of activity. In this case, the activity was dependent on both BET surface area and the ratio of $Mo^{6+}$ with a tetrahedral coordination symmetry to $Mo^{6+}$ with an octahedral one, $Mo^6+[T]/Mo^{6+}[O]$ value.

• Journal of the Korea Concrete Institute
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• v.15 no.6
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• pp.811-819
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• 2003

The corrosion of steel reinforcing bar(re-bar) has been the major cause of the reinforced concrete deterioration. FRP(Fiber-reinforced polymer) reinforcing bar has emerged as one of the most promising and affordable solutions to the corrosion problems of steel reinforcement in structural concrete. However, FRP re-bar is pone to deteriorate due to other degradation mechanisms than those for steel. The high alkalinity of concrete, for instance, is a possible degradation source. Other potentially FRP re-bar aggressive environments are sea water, acid solution and fresh water/moisture. In this study long-term durability performance of FRP re-bar were evaluated. The mechanical and durability properties of two type of CFRP-, GFRP re-bar and one type of AFRP re-bar were investigated; the FRP re-bars were subjected to alkaline solution acid solution, salt solution and deionized water. The mechanical and durability properties were investigated by performing tensile, compressive and short beam tests. Experimental results confirmed the desirable resistance of FRP re-bar to aggressive chemical environment.