• Corrosion Science and Technology
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• v.18 no.3
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• pp.86-91
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• 2019

Generally, atmospheric corrosion is the electrochemical degradation of metal that can be caused by various corrosion factors of atmospheric components and weather, as well as air pollutants. Specifically, moisture and particles of sea salt and sulfur dioxide are major factors in atmospheric corrosion. Using galvanized steel is one of the most efficient ways to protect iron from corrosion by zinc plating on the surface of the iron. Galvanized steel is widely used in automobiles, building structures, roofing, and other industrial structures due to their high corrosion resistance relative to iron. The atmospheric corrosion of galvanized steel shows complex corrosion behavior, depending on the plating, coating thickness, atmospheric environment, and air pollutants. In addition, corrosion products are produced in different types of environments. The lifespans of galvanized steels may vary depending on the use environment. Therefore, this study investigated the corrosion behavior of galvannealed steel under atmospheric corrosion in two locations in Korea, and the lifespan prediction of galvannealed steel in rural and coastal environments was conducted by means of the potentiostatic dissolution test and the chemical cyclic corrosion test.

• Korean Journal of Microbiology
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• v.54 no.4
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• pp.453-455
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• 2018

Bacillus licheniformis strain 0DA23-1, a potential fermentation starter candidate, was isolated from doenjang, a Korean high-salt-fermented soybean food. Strain 0DA23-1 contains a single circular 4,405,373-bp chromosome with a G + C content of 45.96%. The complete genome of strain 0DA23-1 does not include any of the virulence factors found in the well-known pathogens Bacillus cereus and Staphylococcus aureus. Additionally, no genes associated with resistance to eight antibiotics (chloramphenicol, clindamycin, erythromycin, gentamicin, kanamycin, streptomycin, tetracycline, and vancomycin), hemolysis, or biofilm formation were identified.

• Journal of Microbiology and Biotechnology
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• v.32 no.3
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• pp.341-347
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• 2022

In this study, the bacterial community of galchi-baechu kimchi was determined using culture-based and culture-independent techniques (next generation sequencing:NGS), and showed discrepancies between results. Weissella koreensis and Pediococcus inopinatus were the dominant species according to the NGS results, while Bacillus species and P. inopinatus were dominant in the culture-dependent analysis. To identify safe starter candidates, sixty-five Bacillus strains isolated from galchi-baechu kimchi using culture-dependent methods were evaluated for their antibiotic resistance, presence of toxin genes, and hemolytic activity. Strains were then assessed for salt tolerance and protease and lipase activity. As a result, four strains-B. safensis GN5_10, B. subtilis GN5_19, B. velezensis GN5_25, and B. velezensis GT8-were selected as safe starter candidates for use in fermented foods.

• Animal Bioscience
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• v.35 no.8
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• pp.1109-1120
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• 2022

Antibiotics used to be supplemented to animal feeds as growth promoter and as an effective strategy to reduce the burden of pathogenic bacteria present in the gastro-intestinal tract. However, in-feed antibiotics also kill bacteria that may be beneficial to the animal. Secondly, unrestricted use of antibiotics enhanced the antibiotic resistance in pathogenic bacteria. To overcome above problems, scientists are taking a great deal of measures to develop alternatives of antibiotics. There is convincing evidence that probiotics could replace in-feed antibiotics in poultry production. Because they have beneficial effects on growth performance, meat quality, bone health and eggshell quality in poultry. Better immune responses, healthier intestinal microflora and morphology which help the birds to resist against disease attack were also identified with the supplementation of probiotics. Probiotics establish cross-feeding between different bacterial strains of gut ecosystem and reduce the blood cholesterol level via bile salt hydrolase activity. The action mode of probiotics was also updated according to recently published literatures, i.e antimicrobial substances generation or toxin reduction. This comprehensive review of probiotics is aimed to highlight the beneficial effects of probiotics as a potential alternative strategy to replace the antibiotics in poultry.

• Journal of Plant Biotechnology
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• v.50
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• pp.225-231
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• 2023

Cold stress is one of the most vulnerable environmental stresses that affect plant growth and crop yields. With the recent advancements in genetic approaches using Arabidopsis and other model systems, genes involved in cold-stress response have been identified and the key cold signaling factors have been characterized. Exposure to low-temperature stress triggers the activation of a set of genes known as cold regulatory (COR) genes. This activation process plays a crucial role in enhancing the resistance of plants to cold and freezing stress. The inducer of the C-repeatbinding factor (CBF) expression 1-CBF module (ICE1-CBF module) is a key cold signaling pathway regulator that enhances the expression of downstream COR genes; however, this signaling module in Panax ginseng remains elusive. Here, we identified cold-signaling-related genes, PgCBF1, PgCBF3, and PgICE1 and conducted functional genomic analysis with a heterologous system. We confirmed that the overexpression of cold- PgCBF3 in the cbf1/2/3 triple Arabidopsis mutant compensated for the cold stress-induced deficiency of COR15A and salt-stress tolerance. In addition, nuclearlocalized PgICE1 has evolutionarily conserved phosphorylation sites that are modulated by brassinsteroid insensitive 2 (PgBIN2) and sucrose non-fermenting 1 (SNF1)-related protein kinase 3 (PgSnRK3), with which it physically interacted in a yeast two-hybrid assay. Overall, our data reveal that the regulators identified in our study, PgICE1 and PgCBFs, are evolutionarily conserved in the P. ginseng genome and are functionally involved in cold and abiotic stress responses.

• Journal of the Korean Society of Visualization
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• v.22 no.1
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• pp.18-27
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• 2024

A series of shock wave pulses with Mach number 2.2 of 100, 200, and 300 shocks were applied to lead sulfide (PbS) nanomaterials at intervals of 5 sec per shock pulse. To investigate the crystallographic, electronic, and magnetic phase stabilities, powder X-ray diffractometry (XRD), diffused reflectance spectroscopy (DRS), and vibrating-sample magnetometry (VSM) were employed. The material exhibited a rock salt structure (NaCl-type structure); XRD results indicated that material is monoclinic with space group C121 (5). Further, XRD results showed shifts due to lattice contraction and expansion when material was subjected to shock wave pulses, indicating stable material structure. Based on the data obtained, we believe that the PbS material is a good choice for high-pressure, high-temperature, and aerospace applications due to its superior shock resistance characteristics.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.5
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• pp.1741-1746
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• 2010

This study is on development of UV-cured anti-stain coating compounds which have more improved anti-stain function to prevent a surface of PVC tile from stain. To make an anti-stain coating composition, water soluble antistatic agent made from ammonium(IV) salt, antistatic agents for acrylic and polyurethane were used. Their contents varied from 5 to 20wt% against quantities of resin in coating composition. After coating PVC tiles using bar-coating method that can adjust a thickness, we estimated surface properties of coated layer such as anti-stain, electric resistance, adhesive power, thickness of coating, and so on. Results showed that a coating composition added 15wt% of water soluble antistatic agent and coated with No.12 bar-coater had the optimum surface property in electric resistance($3.24{\times}10^9{\Omega}/cm^2$), anti-stain(ink Test, Dust Test) and adhesive power. We could also find electric resistance and anti-stain effect were improved as antistatic agent content increased. However, excessive addition of antistatic agents(over 20wt%) caused the migration.

• Polymer(Korea)
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• v.36 no.4
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• pp.531-535
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• 2012

Conductive polyaniline (PANI) nanofibers in UV-curable resin were used for a transparent conductive film. The emeraldine-salt PANI (ES-PANI) nanofibers were prepared by chemical oxidation polymerization of aniline, which could be changed into emeraldine-base PANI by dedoping. EB-PANI nanofibers as a precursor for conductive fillers were thereby transformed into re-dpoed PANI (rES-PANI) by dodecylbenzenesulfonic acid in the UV-curable resin solution. rES-PANI nanofibers have high conductivity and long-term stability in the solution without a defect of nanostructure. The resulting conductive resin solution was proved to be highly stable where no precipitation of rES-PANI fillers was observed over a period of 3 months. The transparent film was spin-casted on a poly(methyl methacrylate) sheet of thickness ca. $5{\mu}m$. A surface resistance of $6.5{\times}10^8{\Omega}/sq$ and transmittance at 550 nm of 91.1% were obtained for the film prepared with a concentration of 1.4 wt% rES-PANI nanofibers in the solution. This transformation process of rES-PANI from ES-PANI by dedoping-redoping can be an alternative method for the preparation of an antistatic protection film with controllable surface resistance and optical transparencies with the PANI concentration in UV-curable solution.

• Journal of Life Science
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• v.29 no.6
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• pp.697-704
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• 2019

This study performed to investigate the probiotic properties of lactic acid bacteria 200 strains isolated from traditional fermented foods. Based on being higher tolerance to bile salts and showing higher acid resistance, 4 LAB Strains were selected in the screening experiment; Lactobacillus plantarum SRCM 102224, Lb. plantarum SRCM102227, Lb. paracasei SRCM102329, Lb. paracasei SRCM102343. Antibacterial activity against various pathogens, acid and bile salt tolerance, hemolytic phenomenon, cell surface hydrophobicity, and antibiotic resistance were examined. Among the tested strains, SRCM 102343 (95.9%) was highly observed hydrophobicity compared to Lb. rhmanosus GG (13.4%) as control. In this study, the in vitro adhesion properties of 4 strains of LAB was investigated using human intestinal caco-2 cell cultures. SRCM102329 and SRCM102343showed higher adherence to caco-2 cells than Lb. rhamnosus GG. The antibacterial activities of 4 strains LAB were investigated. the 3 strains showing strongly antimicrobial activity against Escherichia coli ATCC10798, Staphylococcus aureus KCCM11593, Listeria invanovii KCTC3444, Bacillus cereus ATCC11778 and S. enterica serovar. Typhi KCTC1926. These results suggest that selected strains have good probiotic potential for application in functional foods.

• Applied Chemistry for Engineering
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• v.35 no.4
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• pp.303-308
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• 2024

Currently, lithium secondary batteries have been used as medium- or large-sized energy sources such as electric vehicles and energy storage system (ESS) due to their high energy and eco-friendly characteristics. Currently commercialized lithium secondary batteries do not fully meet the demands for high energy density and safety. Many studies on solid electrolytes are being conducted to satisfy these requirements. In order to commercialize a solid electrolyte, it is important to supplement the low ion conductivity and high interface resistance with an electrode compared to the organic liquid electrolyte. Therefore, in this study, oligo(3,4-ethylenedioxythiophene (EDOT)) is added to poly(vinyl alcohol) (PVA), which is a polymer matrix with ion conductivity and sticky characteristics, to decrease the interfacial resistance with the same type of polythiophene (PTh)-based electrode. In addition, the addition of porous silicon dioxide (SiO₂) filler improves lithium salt dissociation ability and increases ionic conductivity. And the electrochemical stability of the solid electrolyte, which has been lowered due to additives, is improved by introducing a cross-linked structure using boric acid (BA).