• Mycobiology
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• v.29 no.3
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• pp.176-178
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• 2001

A soft rot of fruits caused by Rhizopus stolonifer occurred on cherry tomato in Jinju City Agricultural Products Wholesale Market, Korea. The disease infection usually started from wounding after cracking of fruits. At first, the lesions started with water soaked and were rapidly softened and diseased lesion gradually expanded. The mycelia grew vigorously on the surface of fruits and formed stolons. Colonies on potato dextrose agar at $25^{\circ}C$ were white cottony at first, becoming heavily speckled by the presence of sporangia and the browinish black, and spreading rapidly by means of stolons fired at various points to the substrate by rhizoids. Sporangia were $82.7{\times}196.7{\mu}m$ in size and globose or sub-globose with somewhat flattened base. The color of sporangia was white at first and then turned black with many spores, and never overhanging. Sporangiophores were $2.6{\sim}5.8{\times}12.3{\sim}24.2{\mu}m$ in width, smooth-walled, non-septate, tight brown, simple, long, arising in groups of $3{\sim}5$ from stolons opposite rhizoids. Sporangiospores were $8.2{\sim}18.8{\mu}m$ long, irregular, round, oval, elongate, angular, and browinish-black streaked. Columella was $64.1{\times}136.3{\mu}m$. brownish gray, and umberella-shaped when dehisced. The causal organism was identified to be R. stolonifer. This is the first report of Rhizopus soft rot on cherry tomato caused by R. stolonifer in Korea.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.6 no.2
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• pp.28-33
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• 2010

As a part of license renewal for the continued operation of Wolsong unit 1, the periodic safety review report was submitted near the end of design lifetime, 2012, and now is under reviewing. Major components of primary system such as pressure tubes, feeder pipes and so on are being replaced and many components of secondary system are also being repaired. So the license renewal of Wolsong unit 1 is expected to be acquired without significant issues. But on the other hand, steam generators of Wolsong unit 1 had the good performance and therefore the replacement and repair for the steam generator are not needed. Recently it is reported that some cracks were detected in a few of european steam generator with Alloy 800 tubes and the cause of cracks was the outer diameter stress corrosion cracking(ODSCC) due to the concentration of chemical impurities on the outer surface of tube. Accordingly the overall review on this issue was performed. The long-term operation is likely to results to form the concentration mechanism for the tube corrosion as the sludge build-up in the secondary side of steam generator and the crack in the crevice between tube and tube-sheet and expansion transitions is apt to be occurred. In this paper, the history of steam generator inspection and operation of Wolsong unit 1 are reviewed and the reliability of steam generator tube is evaluated and the steam generator aging management program for Wolsong unit 1 is introduced.

• Journal of Ocean Engineering and Technology
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• v.20 no.2 s.69
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• pp.59-65
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• 2006

Steel, as a reinforcing mechanism in concrete, provides the tensile strength that is lacking in concrete, alone, and the high alkaline environment (pH 12.5) in concrete offers satisfactory protection against most corrosion of the steel. However, the corrosion of reinforcing steel in concrete can occur by chloride attack or carbonation, and it can cause a loss of integrity a section and concrete failure through cracking and spalling. In this study, a transient electro magnetic method (TEM) of a nondestructive technique is adapted to study the measuring method of steel corrosion in mortar. The sensor was made of an enameled wire, with a diameter of 0.25mm and anacril. He sensor configuration used was a coincident loop type. The secondary electro motive force (2nd EMF) was measured with SIROTEMIII, which equipped the accelerator. The accelerator allowsthe transmitter to turn off approximately $10\sim15$ times faster than normal. The high-resolution time series, used for very shallow or a high resistivity investigation was selected. After steels were corroded by the salt spray, during 4, 8, 15 and 25 days, they were embedded in mortar. The content results acquired in this study are as follows. The variation of the secondary electro motive force (2nd EMF) was shown by the change of steel surface with different corrosion time steel. It was confirmed that measurement of steel corrosion in mortar by a transient electro-magnetic method (TEM) can be possible.

• Journal of the Korea Institute of Building Construction
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• v.15 no.2
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• pp.185-192
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• 2015

Expansion joint is the essential element of the bridge in many cases. When the bridge faces chloride of preventing freezing on the surface of the bridge, the expansion joints is damaged significantly, thus this reduces service life and increases maintenance cost of the bridge. As a solution of this problem, new technology using high ductile materials for the joint without expansion joint was developed and in this research, crack control performance, preventing leaking after the cracking, and chloride resistance were experimentally evaluated. As a result of the experiment, with PCM and FRC materials, the connecting joint suffered poor crack dispersion and severe damage by the chloride penetration while with high-ductile material, the connecting joint dispersed the tensile deformation to microcracks stably up to 7.5mm. Furthermore, under the sever conditions, the leaking was prevented and penetration of chloride ions was prevented after the crack occurred.

• Journal of Convergence for Information Technology
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• v.10 no.3
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• pp.217-226
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• 2020

The study was conducted to investigate the improvement nail health in middle-aged women aged 40~60 years who intake soybean koji by incubating Aspergillus oryzae(황국균), and utilized non-fermented soybeans as a control group and soybean koji as an experiment group for eight weeks. After clinical trials, the lifting and cracking conditions of the nails in the experiment group were improved, The moisture content increased 5.1 times compared to the control group, The water loss was 1.4 times less the reduction to the control group. and nail thickness increased by 1.9 times compared to controls. Wrinkles on the surface improved by about 2.4 times compared to the control group. In conclusion, consumption of this soybean koji of A. oryzae's has been shown to have an impact on improving nail is expected to be used Therefore, I propose this soybean koji of A. oryzae's as an inner beauty for improving nail is in middle-aged women aged 40~60 years.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.2993-2999
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• 2015

Steel companies are applying Ni-B or Ni-Co alloy plating to protect the surface of Continuous casting mold, and they are using saccharin polish which causes crack on plating layer due to sulfur in saccharin. It is considered that the Ni-S compound causes the cracking and additional tensile stresses. The Ni-Mn-B ternary alloy plating was developed for suppression of crack by forming Mn-S compound before Ni-S compound is formed, but there were no domestic or international standard on the Ni-Mn-B alloy plating. Therefore, reliability evaluation standard was established to evaluate the newly developed Ni-Mn-B plating. To develop accelerating life testing method, FMEA(Failure Mode & Effective analysis) was used to analyze the cause of the main failure in plating. The Ni-Mn-B reliability standard included accelerating life test method, and it was categorized by the fundamental performance test, environment test, and accelerated life test, and was designed to guarantee 1 000 hours of B10 life with 80 % reliable level.

• The Korean Journal of Food And Nutrition
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• v.20 no.3
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• pp.282-288
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• 2007

The quality characteristics of cookies between fresh shredded garlic(FSG) and heat-treated($150^{\circ}C$, 5 min) shredded garlic (HT-SG) were comparatively analyzed based on different content additions. The levels investigated were 0, 0.5, 1, 2, 4 and 6% for both shredded garlics. Dough pH was lower in the FSG-added cookies than in the HT-SG-added cookies. The spread factor decreased with the addition of shredded garlic compared to the control($10.63{\pm}0.57$), but differences were insignificant within each group. Cookies hardness was highest at 2% garlic content, and it was higher for HT-SG than FSG. Compared to the measured L-value of the control, the L-values of the test samples decreased with increasing garlic contents. With increasing garlic contents, the a-value increased, but the b-value remained mostly unchanged, with less significant difference compared to the control. The color of the HT-SG group tended to be brown as the garlic content increased. The degree of browning was more pronounced for HT-SG than FSG. Surface cracking of the cookies tended to be higher in the FSG samples than in HT-SG. Compared to the control, garlic taste and flavor increased remarkably with increasing garlic content, and they were stronger for the FSG cookies. The overall acceptability of HT-SG was relatively high, and it was highest for the HT-SG cookies with a 0.5~2% garlic contents than for the control cookies.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.6 s.58
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• pp.126-134
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• 2009

Generally, reinforced concrete structures exposed to the outside temperature are affected by freezing and thawing process during winter and early spring. These freeze-thawing process can lead to the reduction in durability of concrete as cracking or surface spalling. This paper is to study the flexural behavior of RC beams exposed to freeze-thawing environments. To compare the difference in flexural behavior of RC Beams, limited tests were conducted under different types of Longitudinal steel ratio and freeze-thawing cycles. For this purpose, fourteen small-scale RC beams ($100mm{\times} 100mm {\times}600mm$) were strengthened in monotonic and cyclic loadings, subjected to up to 150, 300 cycles freeze-thawing from $-18{\sim}4^{\circ}C$. It is thought that experimental results will be used as basic data to evaluate flexural behavior of RC beams exposed to freeze-thawing.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.1
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• pp.156-164
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• 2010

A total of 6 stepwise constructions were made for building the floating mass concrete foundation. The optimal curing strategies and specialized construction guidelines were adoptively extracted from the 1.5m cube mock-up test prior to the main concrete work. Two different thermal crack index(TCI) calculations from current construction manual exhibit relatively low values as comparing the measured temperature data. This implies that the hydration-induced cracking could be developed in parts of concrete mass. However, the controversial phenomenons in reality were observed. No significant surface cracks are detected at the successive construction stages. Thereby, this paper raises the question regarding on the existence of characteristic length with varying size and shape of a target specimen which are missing in the current construction manual. The isothermal core area and high thermal gradient area in the edge volume should be identified and be introduced to TCI calculation for the purpose of an accuracy.

• Structural Engineering and Mechanics
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• v.76 no.4
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• pp.465-477
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• 2020

This paper presents an investigation on the dynamic behavior of SRC columns with built-in cross-shaped steels under impact load. Seven 1/2 scaled SRC specimens were subjected to low-speed impact by a gravity drop hammer test system. Three main parameters, including the lateral impact height, the axial compression ratios and the stirrup spacing, were considered in the response analysis of the specimens. The failure mode, deformation, the absorbed energy of columns, as well as impact loads are discussed. The results are mainly characterized by bending-shear failure, meanwhile specimens can maintain an acceptable integrity. More than 33% of the input impact energy is dissipated, which demonstrates its excellent impact resistance. As the impact height increases, the flexural cracks and shear cracks observed on the surface of specimens were denser and wider. The recorded time-history of impact force and mid-span displacement confirmed the three stages of relative movement between the hammer and the column. Additionally, the displacements had a notable delay compared to the rapid changes observed in the measured impact load. The deflection of the mid-span did not exceed 5.90mm while the impact load reached peak value. The impact resistance of the specimen can be improved by proper design for stirrup ratios and increasing the axial load. However, the cracking and spalling of the concrete cover at the impact point was obvious with the increasing in stiffness.