• Journal of Preventive Medicine and Public Health
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• v.36 no.1
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• pp.77-84
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• 2003

Objectives : Two related cases of Hemolytic-Uremic Syndrome (HUS) were reported to the Korea National Institute of Health in May, 2001. Shiga toxin 2 genes were detected in both stool samples. We suspected an enterohemorrhagic Escherichia coli (EHEC) infection as the cause of the HUS, and conducted an investigation to find the source of the infection and its route of transmission. Methods : We peformed case investigations on these two related HUS cases, and obtained interviews and rectal swabs form the family members and other close contacts. Additionally, we peformed rectal swabs on the cattle raised by the household of the index patient. Results : We found a 20 month old index patient and a 6 year-old cousin had developed HUS, where there had been a 2 day history of contact with the index, and bacteriological examinations for these two patients revealed, indistinguishably, the same E. coli O171. The grandmother of the index patient was found to be asymptomatic, but E. coli O26 was isolated. We also found a probable case in the mother of the cousin. She reported a history of contact with the index, and developed bloody diarrhea of 3 days duration. The test results for the cattle revealed E. coli O26 in one cow, and E. coli O26 and O55 in another. E. coli O26, which was isolated in both cows and the grandmother of the index, were indistinguishably the same. Conclusions : We found that the E. coli O26 in the grandmother had originated from the cows, and that the E. coli O171 found in the index patient had been transmitted to the cousin through person-to-person contact.

• Journal of Nutrition and Health
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• v.24 no.4
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• pp.308-313
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• 1991

This study attempted to measure subcutaneous fat thickness by the use of ultrasonic wave in age and sex matched Korean subjects, and to observe correlation between fat thick-ness and physical indices. In male, fat thickness of suprailiac area showed the highest value of $9.40{\sim}9.51mm$ and then subscapular was $6.60{\sim}6.84mm$, femoral was $6.48{\sim}7.04mm$ and triceps regions was $3.48{\sim}3.69mm$. In female, femoral subcutaneous fat thickness was the higher. $11.85{\sim}12.15mm$and then suprailiac was $8.79{\sim}9.87mm$ subscapular was $6.20{\sim}6.91mm$ and triceps fat thickness was $4.80{\sim}4.93mm$. In male, fat thickness of triceps and relative body weight(RBW). body mass index(BMI), triceps or $R\ddot{o}hrer$ index were positively correlated. Correlations between suprailiac and weight, relative body weight(RBW). body mass index(BMT), $R\ddot{o}hrer$ index or subscapular were positively significant. In female. there were positive correlations between fat thickness of femoral and RBW, BMI, or $R\ddot{o}hrer$ index. And there were no positive correlations in other parts of the body.

• Korean Journal of Optics and Photonics
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• v.19 no.6
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• pp.435-438
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• 2008

D2O, which is used in nuclear power generation, is slightly different from $H_2O$. $D_2O$ consists of deuterium (D), which is an isotope of hydrogen (H) and has one more neutron than H. $D_2O$ is heavier by about 11% than $H_2O$, and $D_2O$ is present in water in natureat about 0.002%. Its melting point and boiling point are $3.81^{\circ}C$ and $101.42^{\circ}C$, respectively. $D_2O$ is harmful to the human body if it replaces water in the human body by more than $25%{\sim}50%$. We have measured the index of refractive and power absorption of 0%, 25%, 50%, 75%, and 100% of $D_2O$ in $H_2O$ using terahertz time-domain spectroscopy, and we have found that the refractive index decreases and power absorption also decreases as the concentration of $D_2O$ increases.

• Journal of the Korean Ceramic Society
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• v.42 no.3 s.274
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• pp.178-181
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• 2005

Silicon oxynitride (SiON) layers deposited upon a $SiO_2/Si$ buffer layer placed upon silicon wafers have been obtained by using PECVD from $SiH_4,\;N_2O$, and $N_2$. It can be seen that the refractive index, measured by using a prism coupler, for the SiON films can be varied between 1.4480 and 1.4958 at a wavelength of 1552 nm by changing the process parameters. Optical planar waveguides with a thickness of $6{\mu}m$ and a refractive index contrast ($\Delta$n) of $0.36\% have been deposited. Also, etching experiments were performed using ICP dry etching equipment on thick SiON films grown onto Si substrates covered by a thick $SiO_2$ buffer layer. A polarization maintaining single-mode fiber was used for the input and a microscope objective for the output at $1.55{\mu}m$. As a result, a low index contrast SiON based waveguide is fabricated with easily adjustable refractive index of core layer. It illustrates that the output intensity mode is a waveguiding single-mode.

• Korean Chemical Engineering Research
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• v.53 no.6
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• pp.776-782
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• 2015

$TiO_2-SnO_2$ nanoparticles with an average diameter of 3~5 nm were synthesized by hydrolysis of titanium tetraisopropoxide (TTIP) and tin chloride to depress the photocatalytic activity of $TiO_2$ nanoparticles. Organic-inorganic hybrid coating solutions were prepared by reacting the $TiO_2-SnO_2$ nanoparticles with 3-glycidoxypropyl trimethoxysilane (GPTMS) by the sol-gel method. The hard coating films with high refractive index were obtained by curing thermally at $120^{\circ}C$ after spin-coating the coating solutions on the polycarbonate (PC) sheets. The coating films from $TiO_2-SnO_2$ nanoparticles showed an improved pencil hardness of 3H compared to 2H of the coating films from $TiO_2$ nanoparticles. Besides, the refractive index of the coating films from $TiO_2-SnO_2$ nanoparticles enhanced from 1.543 to 1.623 at 633 nm as the Sn/Ti molar ratio increased from 0 to 0.5.

• Korean Journal of Materials Research
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• v.32 no.9
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• pp.379-383
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• 2022

In this study, Barium Germanium glasses were prepared with a composition of xBaO-(72-x)GeO₂-8La₂O₃-20ZnO where x = 16.0, 18.0, 20.0, 22.0 and 24.0 mol% respectively. Their physical and optical properties, such as refractiveness index, glass transition temperature (T_g), softening temperature (T_s), transmittance and Knoop hardness were studied. The results showed that refractive index, T_g, T_s and coefficient of thermal expansion (CTE) increased with increasing BaO concentration. The refractive index of all the prepared samples was observed between 1.7811 to 1.7881. The Abbe number was calculated by formula using n_d (589.3 nm), n_f (656.3 nm) and n_c (486.1 nm) and observed to be between 38 to 40. The Abbe number of the prepared sample was similar to that of BaO and GeO₂. The transmittance of the prepared glasses was observed to be between 80 ~ 82 % throughout the range from 200 nm to 800 nm. Knoop hardness divided into seven steps were measured 5 class (≥ 450 ~ < 550) of all prepared samples.

• Korean Journal of Materials Research
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• v.32 no.12
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• pp.560-564
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• 2022

In this study, lanthanum boron silicate glasses were prepared with a composition of x Li₂O-(60-x)B₂O₃-5CaO-5BaO-7ZnO-10SiO₂-10La₂O₃-3Y₂O₃ where x = 1,3,5,7, and 9 mol%. Each composition was melted in a platinum crucible under atmospheric conditions at 1,400 ℃ for 2 h. Clear glasses with a transmittance exceeding 85 % were fabricated. Their optical, thermal, and physical properties, such as refractive index, Abbe number, density, glass transition (T_g) and Knoop hardness were studied. The results demonstrated that refractive index was between 1.6859 and 1.6953 at 589.3 nm. The Abbe number was calculated using an equation for 589.3 nm (nd), 656.3 nm (nf) and 486.1 nm (nc) and was observed to be in the range from 57.5 to 62.6. As the Li₂O content increased, the glass transition temperature of the optical glass decreased from 608 ℃ to 564 ℃. If glass mold pressing is performed using a material with a low transition temperature and high mechanical strength, then the optical glasses developed in this study can be completely commercialized.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.4
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• pp.376-380
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• 2008

The optical properties of multi layered thin films with $Sb_2O_3/Na_3AlF_6/Sb_2O_3/Cr$ were simulated by using EMP(Essential Macleod Program). EMP is a comprehensive software package to design and analyse the optical characteristics of multi-layered thin film. $Sb_2O_3$ and $Na_3AlF_6$ were selected as a high refractive index and low refractive index material respectively. Additionally Cr was chosen as mid reflective material. Optical properties including color effect were systematically studied in terms of different optical thickness of low refractive index material. The optical thickness of $Na_3AlF_6$ was changed as 0.25, 0.5, 0.75 and $1.0\lambda$. The film with 0.25, 0.5, 0.75 and $1.0\lambda$ of optical thickness showed mixed color range between purple and red range, yellowish green and bluish green, purple and mixed color range of green and purple respectively.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.29 no.3
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• pp.43-50
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• 1997

The purpose of this study was to decrease pollutants of effluents from KP bleaching. Multistage bleaching that combined with O, Eo, and C/D stage was conducted, after optimum bleaching conditions of O, Eo, and C/D stage were determined. Moreover the properties for bleached pulps and pollution level of bleaching effluent were measured by each standard method. Due to increase on the brightness and delignification of pulps by O, Eo, and C/D stage bleaching. It was possible that bleaching sequences were reduced from five stage to four stage. In addition to, OC/DEoD and OC/DEopD bleaching sequences had higher brightness than CEDED bleaching sequence. The pulps bleached by O and Eo stage had higher in tensile index than conventional bleaching sequences with the similar results in burst and tear index. While each bleaching sequences had little differences, bleaching sequences with Eo stage had higher in physical properties than with Eop stage. The pollution level measured by Chemical Oxygen Demand(COD), Biochemical Oxygen Demand(BOD) and Color of bleaching effluents were much lower in combined bleaching sequences of O, Eo and C/D stage than that of CEDED sequence. Particularly, a pollution index of bleaching effluents generated by C/DEoDEB and OC/DEopDED bleaching sequences were lower than that from the other bleaching sequences.

• Journal of Periodontal and Implant Science
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• v.27 no.3
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• pp.561-573
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• 1997

The keratinized mucosa around the implant is an important key in health of soft tissue and hard tissue. The purpose of this study is showed that the keratinized mucosa is associated with the keratinized mucosa index, plaque index, gingival index, probing depth. which is investigated to observing the peri-implant mucosa of mandibular partial edentulous patuent using periodontal parameter by previously published paper. It was estimated 6 site with regard to 80 fixture for 28 person, and the average age is 46.8. Each estimation is the order of less trauma, that is, plaque index, keratinized mucosa index, gingival index and probing depth. In this study, statstically analyzed treatment is used for Spss V 7.0 for Windows(Spss Inc, USA). The Kruskal Walis Test is used to compare the amount of the keratinized mucosa is into the $0{\sim}3$ index, with plaque index, gingival index and probing depth. Mann-whitney Test is used to interpreate the relation of plaque index and probing depth, which is showed significant difference. The Result are as follows 1. The kertinized mucosa index 3 amounts to 47.7%, which is much higher than the other indices and the index order is followed 3, 1, 2 and O. 2. The plaque index 1 amounts to 61.7%, which is much higher than the other indices and the index order is followed 1, 2, 3 and O. The plaque index 0 is significant to each of index(P<0.05). The plaque index is decrease as the keratinized mucosa index is increased. 3. The probing depth for 2mm, 1mm, 3mm is 48.9%, 23.5%, 16.8% respectively, which is most occupied. The probing depth 2mm and 3mm for the keratinized mucosa index is significant(P<0.05). The probing index is decreased as the keratinized mucosa index is increased. 4. The gingival index 0 amounts to 58.0%, which is much higher than the other indices and the index order is followed 0, 1, 2 and 3.