• Proceedings of the Korean Institute of Surface Engineering Conference
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• 1999.10a
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• pp.33-33
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• 1999

• Journal of the Korea Convergence Society
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• v.9 no.4
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• pp.93-98
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• 2018

This study was wanted to confirm ability for UV blocking according to its material. The lenses materials were Acryl, CR-39, NK-55, and MR-8. It was grouped: Group A consisting of anti-scratch hard coated lenses and anti-refractive multi coated lenses, Group B added UV blocking coating on the group A, and Group C consisting of only UV blocking lenses. The results measured UV transmittance, On the UV-A wavelength, Group A showed the UV transmittance of 7.726%, 0.043%, 0.007%, and 0.007% respectively. Group B showed 0.038%, 0.037%, 0.007%, and 0.007%, respectively. The UV-blocking performance of CR-39 has been greatly improved. Group C has shown the best UV blocking function; only 0.005% and 0.004% of UV transmittances.(1.60 and 1.67 index of refraction respectively). For the low power of lenses and sunglasses, the CR-39 lens is the most used. Therefore, to UV blocking from the lens, new materials or UV absorbers or UV coating technology and development of Converged Technologies are required.

• Archives of Craniofacial Surgery
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• v.14 no.2
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• pp.81-88
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• 2013

Background: To suggest the need of more aggressive reduction techniques than closed reduction (CR) technique in nasal fracture treatment, we identified the usefulness of algorithm oriented treatment of nasal fracture that includes indirect open reduction (IOR) and external fixation (EF) as well as the CR. Methods: We compared the clinical course of the group A (n=128) where only the CR was performed regardless of the pattern of the nasal fracture and the group B (n=127) where algorithm oriented treatment including IOR and EF as well as CR was performed depending on the pattern of nasal fracture. And the degree of postoperative pain after CR and IOR technique was compared through the dose of analgesics and pain scores. Results: More than 80% of patients were satisfied the result of reduction in both group A and B. Good contour of nasal bone after reduction was showed 71% of group A and 81% of group B without significant difference. Minor (p>0.05) and major (p<0.05) deformity after reduction were less occurred in the group B than group A. Postoperatively, the dose of analgesics was significantly lower after IOR technique than CR technique (53 mg vs. 142 mg) (p<0.05). Conclusion: Algorithm oriented treatment of nasal fracture including IOR and EF as well as CR reduce major deformity after reduction than treatment of CR alone. It is useful to perform the more aggressive reduction techniques such as IOR and EF according to the pattern of fracture in treatment of nasal fracture.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.7
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• pp.1654-1660
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• 2009

Two different cutting-oils from H and B companies which are sold as an eco-friendly cutting-oils were selected and the biodegradability of these commercially available cutting-oils was evaluated by the sequencing batch reactor (SBR) processes. The cutting-oil wastes ($H_1$) pre-treated by coagulation/flocculation was used as an influent to SBR. When the F/M ratio was operated 0.04 to 0.08kgCOD/kgMLSS d, removals of $BOD_5$and $COD_{Cr}$were above 97% and 91%, respectively. T-N and T-P removals were above 76% and 81%, respectively. If the diluted cutting-oil wastes ($B_1$) was used as an influent of the SBR, $COD_{Cr}$removals were above 77% at the F/M ratio of 0.01-0.02kgCOD/kgMLSS d. After the cutting-oil wastes was treated by coagulation/ flocculation ($B_2$), $COD_{Cr}$removals was above 85%. If the pre-treated cutting-oil wastes were mixed with a synthetic wastewater ($B_3$) and fed into the SBR in order to mimic the real wastewater treatment plant situation, $BOD_5$and $COD_{Cr}$removals were above 97%, 91%, respectively. T-N and T-P removals were above 79% and 76%. The ratio between $BOD_5$and $COD_{Cr}$, ($COD_{Cr}$-$BOD_5$)/$COD_{Cr}$, indicating the biodegradability of effluent of the SBR, was calculated to 85% and 61%. This means that significant amounts of non-readily-biodegradable organic compounds in the effluent of $H_1$, $B_3$are still present.

• Journal of the Korean Magnetics Society
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• v.18 no.2
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• pp.75-78
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• 2008

$AB_2X_4$(A, B=Transition Metal, X=O, S, Se) are cubic spinel normal ferrimagnets, in which M ions occupy the tetrahedral sites and Cr ions occupy the octahedral sites. Recently, they have been investigated for behaviour of B site ions and A-B interaction. Polycrystalline $[Co_{0.9}Zn_{0.1}]_A[Cr_{1.98}{^{57}Fe_{0.02}}]_BO_4$ compound was prepared by wet-chemical process. The ferrimagnetic transition was observed around 90K. $M\"{o}ssbauer$ absorption spectra at 4.2K show that the well-developed two sextets are superposed with small difference in hyperfine fields($H_{hf}$). The hyperfine fields of $CoCr_{1.98}{^{57}Fe_{0.02}}O_4$ and $Co_{0.9}Zn_{0.1}Cr_{1.98}{^{57}Fe_{0.02}}O_4$ were determined to be 488, 478 kOe and 486, 468 kOe, respectively. We notice that the one of the magnetic hyperfine field values changes with Zn ion substitution. These results suggest the incommensurate states and spin-reorientation temperature($T_S=18K$) changes with Zn ions substitution below spin-reorientation temperature($T_S=28K$) of $CoCr_{1.98}{^{57}Fe_{0.02}}O_4$

• Journal of the Korean Magnetics Society
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• v.1 no.2
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• pp.37-41
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• 1991

Amorphous $Fe_{68.5}Co_5M_3Cu_1Si_{13.5}B_9(M=Nb, Mo, Mn, Cr)$ alloys were prepared by using rapidly quenching techinque and were annealed above their crystallization temperatures. Coercive force, initial permeability and AC power loss of the annealed $Fe_{68.5}Co_5M_3Cu_1Si_{13.5}B_9(M=Nb, Mo, Mn, Cr)$ alloys have been studied systematically. Nanocrystallines are formed in the annealed alloys which include Mo and Nb. Remarkably improved soft magnetic properties are obtained in the alloys whose average grain size is around 10 nm. However, soft magnetic properties of the alloys are degraded when grain size is less than IOnm or larger than 15nm. It is considered that the degradation of soft magnetic properties in the alloys whose average grain size is less than 10 nm is due to the Fe-rich amorphous phase retained at grain boundary during the initial crystallization process.

• Korean Journal of Materials Research
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• v.21 no.9
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• pp.515-519
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• 2011

The purpose of this study was to determine the optimal firing condition and composition for $Al_2TiO_5$ crystal, which is suitable for stable coloration in glazes at high temperatures, using $Cr_2O_3$ as chromophore for the synthesis of $Al_2TiO_5$ system pigments. $Al_2TiO_5$ has a high refractive index and good solubility of chromophore in the $Al_2TiO_5$ lattice, making this structure a good candidate for the development of new ceramic pigments. Pigments were synthesized by using $Al_2O_3$ and $TiO_2$ mainly. Various amounts of $Cr_2O_3$ such as 0.01, 0.02, 0.03, 0.04 and 0.05 mole were also added. Each compound was synthesized at $1300^{\circ}C$, $1400^{\circ}C$, and $1500^{\circ}C$ for 2 hours and cooled naturally. The crystal structure, solubility limit, and color of the synthesized pigments were analyzed by XRD, SEM, Raman spectroscopy, UV and UV-vis. The changes in color as the result of applying 6 wt% of the synthesized pigments to lime barium glaze were expressed as CIE-L*a*b* values. A $Cr_2O_3$ 0.03 mole doped $Al_2TiO_5$ brown pigment was successfully synthesize at $1400^{\circ}C$, and the values of CIE-L*a*b* parameters were L* = 44.62, a* = 3.10, and b* = 17.25. In the case of the pigment synthesized at $1500^{\circ}C$, the brown color was obtained at 0.01 mole and 0.02 mole $Cr_2O_3$, and the CIE-L*a*b* values were 55.34, 1.73, 28.64, and 49.39, 0.51, 21.33, respectively. At $1500^{\circ}C$, the maximum limit of solid solution was 0.03 mole $Cr_2O_3$. The glazed sample showed green color, and the values of the CIEL* a*b* parameters were L* = 45.69, a* = -0.98, and b* = 20.38.

• 한국균학회소식:학술대회논문집
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• 2015.05a
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• pp.33-33
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• 2015

Clubroot disease is the major threat to the production of Chinese cabbage (Brassica rapa L.) in Japan. Although the breeding of the clubtoot resistant (CR) cultivars is one of the most efficient ways to control this disease, the CR cultivars do not always have effects due to the breakdown of resistance. Therefore, it is necessary to develop the breeding strategy to accumulate multiple CR genes in a single cultivar effectively. We have identified two incomplete dominant CR loci, Crr1 and Crr2, which are originated from the European CR turnip Siloga. To investigate the effectiveness of marker-assisted selection (MAS) for CR breeding, the inbred line with Crr1 and Crr2 was crossed with parental lines of the existing CR $F_1$ cultivar of Chinese cabbage, followed by 5 times of MAS and backcrossing. The $F_1$ derived from a cross between the resulting parental lines improved the clubroot resistance as expected and had the same morphological characters as the original $F_1$ cultivar. We have shown that the Crr1 locus comprised two loci: Crr1a, which by itself conferred resistance to the mild isolate; and Crr1b, which had a minor effect, but was not required for Crr1a-mediated resistance. Further genetic analysis suggested that Crr1b was necessary to acquire resistance to the more virulent isolate in combination with Crr2. Molecular characterization of Crr1a encoding TIR-NB-LRR class of R protein revealed that there were at least 4 alleles in Japanese CR cultivars of Chinese cabbage. PCR analysis with Crr1a-specific markers demonstrated that the functional alleles were predicted to be present in European CR turnips, Debra and 77b besides Siloga, whereas rarely in Japanese CR cultivars, indicating that Crr1a is an useful source to improve the resistance of Chinese cabbage cultivars.

• Journal of Powder Materials
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• v.4 no.2
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• pp.113-121
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• 1997

The densification of the compacts of Co+32%Cr+20%W+l.5%C, Co+32%Cr+20%W+3.0%C and Co+32%Cr+20%W+4.5%C sintered under $H_2$ gas or vacuum was investigated. The effect of V and B addition on the densification was also investigated. The densification of these compacts were always incomplete regardless of sintering atmosphere, temperature and time. The amounts of oxygen and carbon in compacts sintered in $H_2$ for 3.6ks at 1523K were 0.105~0.160 mass% and 0.33~0.89 mass%, respectively. And those in vacuum were 0.028~0.032% and 0.957~4.08%, respectively. Relative density(Ds) of Co+29%Cr+17%W+3.0%C compact containing 6%V and Co+32%Cr+20%W+2.97%C compact containing 0.03%B were 99 and 100%, respectively, indicating complete densification by solid phase sintering. Victors hardness of sintered compacts containing 6%V or 0.03%B were 632 and 568, showing 50~60% increase in comparison to those without V or B. These results can be explained in terms of oxidation/reduction of oxides and equilibrium pressure of CO in isolated pore, instead of presence of liquid formation and grain boundary separation from pores due to large grain growth.

• Journal of Korea Foundry Society
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• v.21 no.1
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• pp.15-23
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• 2001

The changes in the microstructures and $D0_3{\leftrightarrow}B2$ transition temperature were investigated for Fe-30at.%AI-5at.%Cr alloy with the ordered $D0_3$, structure when Ti, Hf and Zr were added respectively. The addition of Cr has no effect on the microstructure. However, as the amount of Ti addition increased, the grain size became smaller. Addition of Ti+Hf, Ti+Zr and Ti+Hf+Zr also showed the similar effect. When 20at.% of Ti was added, the second phase precipitates on the substrate. The addition of Cr, Hf and Zr alone has no effect on $D0_3{\leftrightarrow}B2$ transition temperature. However, as the amount of Ti addition increased by 5, 10, 15 and 20at.%, the transition temperatures showed 929, 930, 960 and $930^{\circ}C$ respectively.