• Proceedings of the Korean Ceranic Society Conference
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• 2003.04a
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• pp.224.1-224
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• 2003

• Proceedings of the Optical Society of Korea Conference
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• 2008.02a
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• pp.249-250
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• 2008

We report on the visible photoluminescence of the Tb/Yb co-doped alumino-germano-silicate fibers for visible fiber laser application. By changing the concentration ratios of $Tb^{3+}$ to $Yb^{3+}$, we optimized the solution doping conditions and obtained the highest emission efficiency at 546nm. The luminescence intensity at 546nm was found to increase with the relative increase of $Tb^{3+}$ ions.

• Advances in materials Research
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• v.3 no.4
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• pp.227-232
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• 2014

$Ce^{4+}$, $Eu^{3+}$, $Tb^{3+}$ co-doped $Ca_3Si_3O_8F_2$ phosphor was synthesized via solid state reaction method using $CaF_2$, $CaCO_3$ and $SiO_2$ as raw materials for the host and $Eu_2O_3$, $CeO_2$, and $Tb_4O_7$ as activators. The luminescent properties of the phosphor was analysed by spectrofluorophotometer at room temperature. The effect of excitation wavelengths on the luminescent properties of the phosphor i.e. under near-ultraviolet (nUV) and visible excitations was investigated. The emission peaks of $Ce^{4+}$, $Eu^{3+}$, $Tb^{3+}$ co-doped $Ca_3Si_3O_8F_2$ phosphor lays at 480(blue band), 550(green band) and 611nm (red band) under 380nm excitation wavelength, attributed to the $Ce^{4+}$ ion, $Tb^{3+}$ ion and $Eu^{3+}$ ions respectively. The results reveal that the phosphor emits white light upon nUV (380nm) / visible (465nm) illumination, and a red light upon 395nm / 535nm illumination. RE ions doped $Ca_3Si_3O_8F_2$ is a promising white light phosphor for LEDs. The emission colours can be seen using Commission international de l'eclairage (CIE) co-ordinates. A single host phosphor emitting different colours under different excitations indicates that it is a potential phosphor having applications in many fields.

• Transactions of the Society of Information Storage Systems
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• v.1 no.2
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• pp.127-131
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• 2005

We report a nanometer scale mark formation using a $PtO_x$ thin film or a TbFeCo rare-earth transition metal film and the mechanism. The multi-layer samples($ZnS-SiO_2/PtOx/ZNS-SiO_2,\;ZnS-SiO_2/TbFeCo/ZnS-SiO_2$) were prepared with a magnetron sputtering method on a polycarbonate or a glass substrate. By laser irradiation of approximately a few nanoseconds, nanometer scale marks were fabricated. During the fabrication process, the thin films were thermally reacted or inter-diffused during the laser irradiation. 75 nm bubble marks in the PtOx multi-layer sample by an approximately 4-ns laser irradiation. Inside the bubble mark, Pt particles with a few nanometer sizes are distributed. The $50{\sim}100$ nm bubble marks in the TbFeCo multi-layer sample by a few nanosecond laser irradiations. We will report the detail structure of the samples, the bubble mark formation process and the mechanism.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.344-347
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• 2003

The varistor properties of the ZPCCT-based ceramics, which are composed of Zn-Pr-Co-Cr-Tb oxides, were investigated with $Tb_4O_7$ content in the range of $0.0{\sim}1.0\;mol%$. As $Tb_4O_7$ content is increased, the ZPCCT-based ceramics exhibited very high densification based on increasing density in the range of $5.73{\sim}5.84\;g/cm^3$. The varitor voltage($V_{1mA}$) and nonlinear exponent($\alpha$) was increased in the range of 280.9 to 751.8 and 29.8 to 44.4 with increasing $Tb_4O_7$ content, respectively. In particular, the maximum $\alpha$ of 44.4 was obtained from 1.0 mol% $Tb_4O_7$ and the, minimum leakage current($I_{\ell}$) of $1.0\;{\mu}A$ was obtained from 0.5 mol% $Tb_4O_7$.

• Korean Journal of Food Science and Technology
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• v.37 no.2
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• pp.149-153
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• 2005

Composition and pasting properties of endosperms of one common buckwheat (CB) and two tartary buckwheats (TB) grown in China were investigated. No differences were observed in proximate composition and amino acid content between CB and TB. Content of rutin in TB was 22-fold higher than that of CB. Among minerals, iron, calcium, and magnesium contents were higher in TB than CB, whereas zinc, manganese, and phosphorus contents were similar, Pasting properties measured with Rapid visco Analyzer revealed TB-2 cultivar had highest peak viscosity, trough, and breakdown, followed by TB-1 and CB. Setback of TB was about 2.2-fold greater than that of CB. Significant differences in color were observed between CB and TB, and among TB cultivars.

• Korean Journal of Materials Research
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• v.4 no.2
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• pp.233-240
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• 1994

We have investigated how the magneto-optical and recording properties of Pt/Co modulated films vary with sample preparation conditions : sputtering at various gas pressures, sputtering with Xe instead of Ar, and etching the buffer layers, etc. The magneto-optical characteristics of Pt/Co multilayers was comparable with those of currently prevailing rare-earth transition-metal alloys(Tb-Fe-Co amorphous films). On a disk of $12{\times}[Pt10.7\;{\AA}/Co2.8{\;}{\AA}]$ multilayer enhanced with 70nm silicon nitride, we have achieved a CNR of 36dB with a reading laser(${\lambda}\;=\;780nm$) power of 2.5-4.5mW for 720KHz carrier at 1.4m/s and the enhanced kerr rotation angle of $1.23^{\circ}$ at 780nm. It is suggested that Pt/Co modulated films clearly are very promising magneto-optical materials for a commercially use.

• Food Science and Preservation
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• v.15 no.1
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• pp.161-168
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• 2008

The effects tea beverages (TBs) prepared from powdered green tea (Gt), oolong tea (Ot), black tea (Bt), or pure tea (Pt) with lemon, orange, grenadine etc on cadmium toxicity in rats were investigated Sensory evaluations of the TBs are better than those of each water extracted teas. Cadmium (50 ppm) was administered to experimental rats fed a basic diet, or a diet with various TBs (15% w/v), for 5 weeks. Although body weight gains, feed intakes, and fecal weights in all Cd-treated groups were lower than those in the normal control group (NC), feed efficiency ratio, urine volumes, liver weights, and kidney weights did not differ significantly between groups. The serum ALT and AST levels in the Cd-treated control group (Cd-Co) were higher than those in the NC animals. Serum ALT and AST levels in all Cd-treated rats fed TB-supplemented diets were lower than in animals of the Cd-Co group. Tibia and femur weights in Cd-Co animals were lower than those in NC rats. Tibia and femur weights in Cd-treated rats fed TB-supplemented diets were higher than those in Cd-Co animals. There were no between-group differences in tibia lengths; animals in the NC and TB-supplemented diet groups showed femur lengths longer than those of Cd-Co rats. Although the contents of crude ash and cadmium in the femurs of Cd-Co mts was markedly higher than in the femurs of NC animals, the cadmium content in femurs of Cd-Co rats was significantly lower than that in the femurs of NC animals. The changes in mineral levels caused by Cd administration were alleviated by every TB-supplemented diet tested Whereas fecal calcium excretion by Cd-Co animals was significantly higher than that of NC rats, calcium excretion by Cd-treated rats fed TB-supplemented diets was significantly lower than that of Cd-Co animals. Fecal cadmium excretion by all Cd-treated rats fed TB-supplemented diets was significantly higher than that of Cd-Co animals. In conclusion, this study provides experimental evidence that various TBs may regulate cadmium-induced organ toxicity by reducing cadmium accumulation in tissues through the mechanism of increasing the fecal excretion of cadmium.

• Journal of The Korea Institute of Healthcare Architecture
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• v.27 no.4
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• pp.51-60
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• 2021

Purpose: Tuberculosis(TB) care unit in public health center should be carefully considered to be re-designed as an infection safety environment for both patient and healthcare workers. So, for the enhancement, this study analyses the facility requirements for co-using the screening clinic as a TB and other respiratory disease care unit. Methods: Not only screening clinic facility guidelines from "A Study for Standard Triage Design and Construction Document" but also the guidelines of TB care and related medical facility are reviewed; KDCA, CDC, ECDC and WHO as a TB care, and FGI and NHS for facility. The facility requirements are summarized space, approach, and mechanical requirement in order. By comparing the summary and screening clinic facility guidelines, supplementations are proposed for TB care unit setting. Results: The result of this study shows that both the space program and mechanical requirement of the screening clinic and that of TB care unit are almost identical and could be share, which include direct airflow or negative air pressure in an exam room. To increase functional and economical efficiency, however, it is necessary to consider a multi-functional negative pressured room, So care process may be re-designed based on a room type; face-to-face room or glass wall inbetween. Implications: The facility guidelines for TB care unit of a public health center should be developed to build a safe environment for infection control by reflecting its medical plan and budget.

• The Korean journal of internal medicine
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• v.39 no.2
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• pp.306-317
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• 2024

Background/Aims: To determine whether metformin, which is considered a host-directed therapy for tuberculosis (TB), is effective in improving the prognosis of patients with TB and diabetes mellitus (DM), who have higher mortality than those without DM. Methods: This cohort study included patients who were registered as having TB in the National Tuberculosis Surveillance System. The medical and death records of matched patients were obtained from the National Health Information Database and Statistics Korea, respectively, and data from 2011 to 2017 were collected retrospectively. We classified patients according to metformin use among participants who used diabetes drugs for more than 28 days. The primary outcome was all-cause mortality during TB treatment. Double propensity score adjustment was applied to reduce the effects of confounding and multivariable Cox proportional hazard models were used to estimate adjusted hazard ratio (aHR) with 95% confidence interval (CI). Results: The all-cause mortality rate during TB treatment was lower (9.5% vs. 12.4%, p < 0.01) in the metformin user group. The hazard of death due to all causes after double propensity score adjustment was also lower in the metformin user group (aHR 0.76, 95% CI 0.67-0.86, p < 0.01). There was no significant difference in mortality between metformin users and non-users for TB-related deaths (p = 0.22); however, there was a significant difference in the non-TB-related deaths (p < 0.01). Conclusions: Metformin use in patients with TB-DM co-prevalence is associated with reduced all-cause mortality, suggesting the potential for metformin adjuvant therapy in these patients.