• The Korean Journal of Mycology
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• v.46 no.4
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• pp.479-490
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• 2018

Red pepper is seriously damaged by thrips (Thrips palmi) and anthracnose caused by Colletotrichum acutatum throughout its development. Because of biotic constraints, producers often depend on chemicals that are expensive and have adverse effects on the environment, operator, and beneficial insects. In addition, resistance is developed because of the repeated use of chemicals. In recent decades, the use of microorganisms in crop protection has become a credible alternative because it is eco-friendly. In this study, we aimed to select isolates with insecticidal and fungicidal activities against the pathogens that cause anthracnose and thrips. We treated T. palmi adults and juveniles with 13 strains of entomopathogenic fungi (isolated from the soil by using the insect-bait method), and 6 strains showed excellent insecticidal activity (70-100%) 5 days after the treatment. The selected isolates were cultured with C. acutatum to screen for the strain with excellent anti-fungal activities, among which an isolate FT333 showed more than 95% control efficacy against C. acutatum in vitro. The isolate was identified as Isaria javanica through its morphological characteristics and phylogenetic analysis of the ITS and ${\beta}-tubulin$ nucleotide sequences. The Isaria javanica FT333 isolate could be used effectively for dual bio-control of thrips and anthracnose during red pepper cultivation.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.4
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• pp.525-534
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• 2018

This study evaluated the various qualifications that can be linked to employment similar to the medical laboratory technology major. The qualifications for employment outside the medical laboratory technology major are industrial health instructor, doping control officer, audiologist, sign language interpreter, health education specialist, claim adjuster, Korea life underwriter, administrative manager, hospital administrator, insurance review manager, and hospital coordinator. The qualifications for employment similar to the medical laboratory technology major include the clinical research coordinator, clinical research associate, anatomist, analytical chemistry analysts, hazardous materials industry engineers, biotechnologist, biosafety managers, biotechnology technicians, medical device quality officers, animal care nurse, industrial engineer hazardous material, bioprocess engineer, biosafety officer, certified technology consultant, director of medical device quality control, laboratory animal technician, animal nursing technician, and cruise medical manager. Therefore, it is necessary to conduct a social analysis survey of the various qualifications currently held by medical technologists. In addition, it will be necessary to investigate the current status of medical technologists working in other fields. In the future, medical technologists should expand the scope of their work through efforts to strengthen their individual work capacity, share cases, and strengthen their expertise.

• Korean Chemical Engineering Research
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• v.56 no.6
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• pp.856-863
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• 2018

In order to investigate the re-carbonation behaviors of limestones in an oxy-circulating fluidized bed combustor (Oxy-CFBC), the re-carbonation characteristics of domestic 4 different limestone samples were analyzed in a thermogravimetric analyzer (TGA-N1000) with the higher concentration of $CO_2$. Effect of reaction temperature ($600{\sim}900^{\circ}C$) and $CaCO_3$ content (77~95%) of limestones were determined and the mass change of the CaO was observed. Under the temperature of $800^{\circ}C$, the conversion rate increased with increasing reaction temperature. However, the conversion rate decreased with increasing reaction temperature over $800^{\circ}C$. In the case of $CaCO_3$ content, the conversion was remarkably different at $870^{\circ}C$. In addition, reaction rate equations for simulating the re-carbonation of limestone by using gas solid reaction models were proposed in this study.

• Korean Journal of Heritage: History & Science
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• v.44 no.3
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• pp.4-17
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• 2011

The Baekje's cotton fabrics were excavated from 'Neungsan-ri temple site in Buyeo' (September 1999-April 2000) and stored at Buyeo National Museum after conservation treatment. In this study, it carred out non-destructive, chemical and morphological analysis for fiber identification, also considered on influx, features and difference between the 'Baek-cheop-po(Three kingdom period's cotton fiber)' and 'Mok-myeon(imported by Munikjeom, late Korea dynasty)'. As a result, the fiber proved cellulose fiber through analytical researches like color reaction, FT-IR(chemical analysis). It was also confirmed lumens, typical dimensional structure(morphological analysis) as an features of cotton fiber. The fiber was the first evidence in ancient Korea's cotton. But it can not prove that whether weaving were made in Baekje's area. However there were documentation that people in Beakje make cloth to silk fabric from 'Mahan period'. We can suppose that they have had an old weaving techniques. This study has a great historical, academic values as the only evidence for the hypothesis of a weaving technique of the Baekje's cotton. Through comparison to each region's ancient cottons, we can investigate the species of Baekje's cotton and ancient Korea cotton's influx.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.29 no.4
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• pp.179-186
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• 2019

In this study, we investigated the structural properties of $Ga_2O_3$ thin films and the photo-electrical properties of metal-semiconductor-metal (MSM) photodetectors deposited by Ti/Au electrodes. $Ga_2O_3$ thin films were grown at different temperatures using metal organic chemical vapor deposition (MOCVD). The crystal phase of $Ga_2O_3$ changed from ${\varepsilon}$-phase to ${\beta}$-phase depending on the growth temperature. The crystal structure of ${\varepsilon}-Ga_2O_3$ was confirmed by X-ray diffraction (XRD) analysis and the formation mechanism of crystal structure was discussed by scanning electron microscopy (SEM) images. From the results of current-voltage (I-V) and time-dependent photoresponse characteristics under the illumination of external lights, we confirmed that the MSM photodetector fabricated by ${\varepsilon}-Ga_2O_3$ showed much better photocurrent characteristics in the 266 nm UV range than in the visible range.

• Composites Research
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• v.31 no.6
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• pp.323-331
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• 2018

The effect of stainless steel jagged-pin reinforcement on the pull-off strength of the composite hat-joint was studied by the test. The pins were physically and chemically surface-treated and inserted in the thickness direction over the interface where the skin and stiffener meet. The specimens including the jagged-pins were made by co-curing process. Diameters of the jagged-pins were 0.3, 0.5 and 0.7 mm. The pin areal densities were set to 0.5 and 2.0% based on the interface area where the skin and stiffener meet. The specimens using 0.3 mm diameter normal (un-jagged) pins with 2.0% areal density were additionally fabricated and tested to investigate the pin shape effect on the pull-off strength. The pull-off strengths of specimens reinforced with 0.5% areal density by 0.3, 0.5, and 0.7 mm diameter pins were 45, 19 and 9% higher than those of un-reinforced specimens, respectively. In case with 2.0% pin areal density, the strengths were 127, 45, and 11% higher than those of un-reinforced specimens, respectively. The test results show that the higher pin areal density results in the higher strength when the pin diameter is the same. When the pin areal density is the same, the smaller pin diameter leads to higher strength. When the joints using jagged-pins and normal pins in 2.0% areal density with 0.3 mm diameter, the joints of jagged-pins showed the 64% higher strength. From the results of this study, it was confirmed that jagged-pin reinforcement can be an effective method for improving the pull-off strength of composite hat-joint.

• Clean Technology
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• v.27 no.2
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• pp.182-189
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• 2021

The adsorption of disperse yellow 3 (DY 3) on granular activated carbon (GAC) was investigated for isothermal adsorption and kinetic and thermodynamic parameters by experimenting with initial concentration, contact time, temperature, and pH of the dye as adsorption parameters. In the pH change experiment, the adsorption percent of DY 3 on activated carbon was highest in the acidic region, pH 3 due to electrostatic attraction between the surface of the activated carbon with positive charge and the anion (OH^-) of DY 3. The adsorption equilibrium data of DY 3 fit the Langmuir isothermal adsorption equation best, and it was found that activated carbon can effectively remove DY 3 from the calculated separation factor (R_L). The heat of adsorption-related constant (B) from the Temkin equation did not exceed 20 J mol^-1, indicating that it is a physical adsorption process. The pseudo second order kinetic model fits well within 10.72% of the error percent in the kinetic experiments. The plots for Weber and Morris intraparticle diffusion model were divided into two straight lines. The intraparticle diffusion rate was slow because the slope of the stage 2 (intraparticle diffusion) was smaller than that of stage 1 (boundary layer diffusion). Therefore, it was confirmed that the intraparticle diffusion was rate controlling step. The free energy change of the DY 3 adsorption by activated carbon showed negative values at 298 ~ 318 K. As the temperature increased, the spontaneity increased. The enthalpy change of the adsorption reaction of DY 3 by activated carbon was 0.65 kJ mol^-1, which was an endothermic reaction, and the entropy change was 2.14 J mol^-1 K^-1.

• Clean Technology
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• v.27 no.2
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• pp.146-151
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• 2021

Pure and Sm ion doped BiVO₄ catalysts were synthesized using a conventional hydrothermal method and characterized by XRD, DRS, SEM, and PL. We also examined the activity of these materials on the photocatalytic decomposition of rhodamine B under visible light irradiation. The doping of Sm ion into BiVO₄ catalyst changed the ms-BiVO₄ crystal structure into the tz-BiVO₄ crystal structure in the low synthesis temperature. Light absorption analysis using DRS showed that all the catalysts displayed strong absorption in the visible range of the electromagnetic spectrum regardless of Sm ion doping. In addition, an amorphous morphology was shown in the pure BiVO₄ catalyst, but the morphology of the BiVO₄ catalyst doped with Sm ion was changed into an ellipse shape and also the particle size decreased. In the photocatalytic decomposition of rhodamine B, Sm ion doped BiVO₄ catalyst showed higher photocatalytic activity than the pure BiVO₄ catalyst. In addition, the Sm3-BVO catalyst doped with 3% Sm ion showed the highest photocatalytic activity, as well as the highest formation rate of OH radicals (•OH) and the highest PL peak. This result suggests that the formation rate of OH radicals produced in the interface between the photocatalyst and water is well correlated with the photocatalytic activity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.10-15
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• 2020

Ultraviolet rays, which have wavelengths smaller than 400 nm, are very harmful to the eyes. Recently, high-energy visible light was also revealed to be harmful to retinal cells. Therefore, polymer eyeglass lenses that can block UV and high-energy visible light are needed for eye health. In this study, high-refractive-index polymer eyeglass lens, n=1.67, were manufactured using the injection-mold method with the m-xylene diisocyanate monomer, 2,3-bis((2-mercaptoethyl)thio)-1-propanethiol monomer, benzotriazole UV absorber, release of alkyl phosphoric ester, dye mixture of CI solvent violet 13, and catalyst of dibutyltin dichloride mixture. A multi-layer anti-reflection coating was applied to manufactured polymer eyeglass lenses for both sides using an E-beam evaporation system. The optical properties of the manufactured lenses with the UV and high-energy visible light-blocking function were analyzed by UV-visible spectrophotometry. As a result, the polymer eyeglass lens with a UV absorber of 0.5 wt. % blocked 99% of UV and high-energy visible light shorter than 411 nm. The average transmittance of the polymer eyeglass lens with a UV absorber of 0.5wt.% was 97.9% in the range of 460 ~ 660 nm for photopic eye sensitivity higher than 10%. Therefore, clear image acquisition in photopic vision is possible.

• Applied Chemistry for Engineering
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• v.32 no.1
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• pp.28-34
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• 2021

SiO2/Ag core-shell nanoparticles were synthesized by combining modified Stöber process and reverse micelle method using acetoxime as a reducing agent in water/dodecylbenzenesulfonic acid (DDBA)/cyclohexane reverse micells. The SiO2/Ag core-shells were studied for structure, morphology and size using UV-visible spectroscopy, XRD, SEM and TEM. The size of a SiO2/Ag core-shell could be controlled by changing the [water]/[DDBA] molar ratio (WR) values. The size and the polydispersity of SiO2/Ag core-shells increased with increase of the WR value. The resultant Ag nanoparticles exhibit a strong surface plasmon resonance (SPR) peak at 430 nm over the amorphous SiO2 nanoparticles. The SPR peak shifted to the red side with increase in nanoparticle size. Conductive pastes with 70 wt% SiO2/Ag core-shell were prepared, and the pastes were coated on the PET films using a screen-printing method. The printed paste film of the SiO2/Ag core-shell showed higher surface resistance than the commercial Ag paste in the range of 460~750 µΩ/sq.