• 한국축산식품학회지
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• 제18권3호
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• pp.203-208
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• 1998

The study was carried out to screen mutagenicity of smoking materials for the determination of optimum smoking temperature for meat products. Wood materials employed for smoking were oak and apple trees. Temperatures of the generator for manufacturing of smoke flavoring were set to 250$^{\circ}C$, 400$^{\circ}C$ and 500$^{\circ}C$, respectively. Mutagenic activities of smoke flavoring were assayed according to Ames test using Salmonella typhimurium TA98 and TA 100. In oak wood smoke flavoring, Salmonella typhimurium TA98 without S-9 mix showed strong mutagenic activities at the concentration of 6$\mu\textrm{g}$/plate(250$^{\circ}C$), 4$\mu\textrm{g}$/plate(400$^{circ}C$) and 6$\mu\textrm{g}$/plate(500$^{\circ}C$). Salmonella typhimurium TA100 with S-9 mix showed strong mutagenic activities at the concentration of 10$\mu\textrm{g}$/plate(250$^{\circ}C$), 20$\mu\textrm{g}$/plate(400$^{\circ}C$) and 10$\mu\textrm{g}$/plate(500$^{\circ}C$). Salmonella typhimurium TA98 with S-9 mix showed strong mutagenic activities at the concentration of 30$\mu\textrm{g}$/plate(250$^{\circ}C$), 40$\mu\textrm{g}$/plate(400$^{\circ}C$) and 20$\mu\textrm{g}$/plate(500$^{\circ}C$). Salmonella typhimurium TA100 with S-9 mix showed strong mutagenic activities at the concentration of 30$\mu\textrm{g}$/plate(250$^{\circ}C$), 50$\mu\textrm{g}$/plate(400$^{\circ}C$) and 20$\mu\textrm{g}$/plate(500$^{\circ}C$). Salmonella typhimurium TA100 without S-9 mix showed strong mutagenic activities at the concentration of 10$\mu\textrm{g}$/plate(250$^{\circ}C$), 20$\mu\textrm{g}$/plate(400$^{\circ}C$) and 20$\mu\textrm{g}$/plate(500$^{\circ}C$). Salmonella typhimurium TA98 with S-9 mix showed strong mutagenic activities at the concentration of 30$\mu\textrm{g}$/plate(250$^{\circ}C$), 40$\mu\textrm{g}$/plate(400$^{\circ}C$) and30$\mu\textrm{g}$/plate(500$^{\circ}C$). Salmonella typhimurium TA100 with S-9 mix showed strong mutagenic activities at the concentrations 30$\mu\textrm{g}$/plate(500$^{\circ}C$). Salmonella typhimurium TA100 with S-9 mix showed strong mutagenic activities at the concentration of 30$\mu\textrm{g}$/plate(250$^{\circ}C$), 20$\mu\textrm{g}$/plate(400$^{\circ}C$) and 30$\mu\textrm{g}$/plate(500$^{\circ}C$). From these results, it could be concluded that optimum smoking temperature for meat products should be set below 400$^{\circ}C$, that the compounds like benzo[a]pyrene etc. contain a variety of mutagenic potentials, which could be generated at the higher smoking temperature.

• 한국표면공학회지
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• 제44권5호
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• pp.213-219
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• 2011

Recently aspheric lenses are widely used for superpricision optical instruments, such as cellular phone camera modules, digital cameras and optical communication modules. The aspherical lenses are processed using mold core under high temperature compressive forming pressure. It is imperative to develop superhard protective films for the life extension of lens forming mold core. Especially ta-C films with higher $sp^3$ fractions receive attentions for the life extension of lens forming mold and, in turn, the cost reduction of lenses due to their suprior high temperature stability, high hardness and smooth surfaces. In this study ta-C films were processed on WC mold as a function of substrate bias voltage using FVA (Filtered Vacuum Arc) method. The processed films were characterized by Raman spectroscopy and nano-indentation to investigate bonding nature and hardness, respectively. The film with maximun 87% of $sp^3$ fraction was obtained at the substrate bias voltage of -60 V, which was closest to ta-C film. ta-C films showed better high temperature stability by sustaining relatively high fraction of $sp^3$ bonding even after 2,000 glass lens forming applications.

• 한국재료학회지
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• 제1권1호
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• pp.17-22
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• 1991

불순물이 주입된 실리콘 기판에 500 두께의 탄탈륨 박막을 증착한 후 실리사이드를 형성시키기 위해 아르곤 분위기에서 급속열처리(RTA)률 하였다. 형성된 $TaSi_2$와 불순물의 거동은 XRD, SEM, 4-point probe, HP4145와 SIMS로 조사하였다. 불순물의 종류에 관계없이 $TaSi_2$는 RTA 온도가 $800^{\circ}C$일때 형성되기 시작하였으며 $1000^{\circ}C$이상에서 증착된 Ta가 전부 $TaSi_2$로 상 전이가 일어났다. 또한 $TaSi_2/P^+$영역에 대한 접촉저항간은 contact size가 $0.9{\times}0.9({\mu}{m^2}$)일때 $22{\Omega}$ 낮은값을 가졌으며 이온 주입된 불순물은 RTA처리시 형성된 $TaSi_2$층으로 out-diffusion이 일어났다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.1014-1017
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• 2001

In recent years, The tantalum nitride(TaN) thin-film has been developed for the electronic resistor and capacitor. In this papers, The effect of thermal annealing in the temperature range of 300∼700$^{\circ}C$ on the sheet resistor properties and microistructure of tantalum nitride(TaN) thin-film deposited by RF sputtering was studied. XRD(X-ray diffractometer) and AFM were used to observe electrical properties and microstructrue of the TaN film and sheet resistance. The TCR properties of the TaN films were discussed in terms of annealing temperature, ratio of nitrogen, crystallization and thin films surface morphology due to annealing temperature. The leakage current of the TaN thin film annealed 400 $^{\circ}C$ was stabilized in the study. How its was found that the sheet resistance in the polycrystalline TaN thin film decreased with increasing the annealing temperature above 600 $^{\circ}C$ after sudden peak upen 400 $^{\circ}C$.

• 대한화학회지
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• 제35권6호
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• pp.653-658
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• 1991

Sol-gel법을 통하여 만들어진 비정질 Ta-IPA 괴상과 박막을 $25^{\circ}C$와 $340^{\circ}C$로 열처리한 구조의 차이점과 구조수와의 관계를 TG-DTA, IR과 X-선회절 강도측정으로부터 구한 동경분포곡선 등을 이용하여 알아보았다. 각 시편들을 L-$Ta_2O_5$ 결정의 물성 및 동경분포곡선(calc-RDF)과 비교하였다. 박막은 8면체-$TaO_6$로 괴상보다 작은 cluster로 구성되어 있었다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권2호
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• pp.67-72
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• 2004

The microwave dielectric properties and microstructure of the (1-x)$Mg_4Ta_2O_{9-x}TiO_2$(X=0, 0.3, 0.4) ceramic were, investigated. The specimens were prepared by the conventional mixed oxide method with sintering temperature of $1350^{\circ}C$∼$1425^{\circ}C$. According to the XRD patterns, the (1-x)$Mg_4Ta_2O_{9-x}TiO_2$(X=0, 0.3, 0.4) ceramics have the $Mg_4Ta_2O_{9}$ phase(hexagonal). The dielectric constant($\varepsilon$$_{\gamma}$) and density increased with sintering temperature and mole fraction of x. To improve the quality factor and the temperature coefficient of resonant frequency, TiO$_2$($\varepsilon_{r}$=100, $Q{\times}f_{r}$=40,000GHz, $\tau$$_{f}$=＋450 ppm/$^{\circ}C$) was added in $Mg_4Ta_2O_{9}$ ceramics. In the case of the $0.7Mg_4Ta_2O_{9}$-$0.3TiO_2$ and the $0.6Mg_4Ta_2O_{9}$-$0.4TiO_2$ceramics sintered at $1400^{\circ}C$ for 5hr., the microwave dielectric properties were $\varepsilon$$_{\gamma}$=11.72, $Q{\times}f_{r}$=126,419GHz, $\tau_{f}$=-31.82 ppm/$^{\circ}C$ and $\varepsilon_{r}$=12.19, $Q{\times}f_{r}$=109,411GHZ, $\tau$$_{f}$= -17.21 ppm/$^{\circ}C$, respectively.

• 전기학회논문지
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• 제56권3호
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• pp.556-560
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• 2007

In this study, both structural and microwave dielectric properties of the $Mg_5B_4O_{15}$ (B=Ta, Nb) cation-deficient perovskite ceramics with sintering temperature were investigated. All sample of the $Mg_5B_4O_{15}$ (B=Ta, Nb) ceramics were prepared by the conventional mixed oxide method and sintered at $1400^{\circ}C{\sim}1500^{\circ}C$. The bulk density and quality factor of the $Mg_5B_4O_{15}$ (B=Ta, Nb) ceramics were increased with increasing sinterning temperature in the range of $1400^{\circ}C{\sim}1450^{\circ}C$, but these were decreased the sintering temperature of above $1450^{\circ}C$. The dielectric constant of the $Mg_5Ta_4O_{15}$ ceramics was increased continuously with increasing sintering temperature. And the dielectric constant of the $Mg_5Nb_4O_{15}$ ceramics was increased in as the sintering temperature increasesfrom $1400^{\circ}C{\sim}1450^{\circ}C$ but was decreased at the temperatures above $1475^{\circ}C$. In the case of the $Mg_5Ta_4O_{15}\;and\;Mg_5Nb_4O_{15}$ ceramics sintered at $1450^{\circ}C$ for 5h, the dielectric constant, quality factor, and temperature coefficient of the resonant frequency (TCRF) were 8.2, 259,473 GHz, $-10.91ppm/^{\circ}C$ and 14, 37,350 GHz, $-52.3ppm/^{\circ}C$, respectively.

• 전기학회논문지
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• 제57권7호
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• pp.1208-1212
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• 2008

In this study, both structural and microwave dielectric properties of the $Ba_5B_4O_{15}$ (B=Ta, Nb) cation-deficient perovskite ceramics with sintering temperature were investigated. All samples of the $Ba_5B_4O_{15}$ (B=Ta, Nb) ceramics were prepared by the conventional mixed oxide method and sintered at $1325^{\circ}C{\sim}1575^{\circ}C$. The bulk density and dielectric constant of the $Ba_5Ta_4O_{15}$ ceramics were increased continuously with increasing of sintering temperature. The quality factor of the $Ba_5Ta_4O_{15}$ ceramics was increased in as the sintering temperature increases from $1375^{\circ}C{\sim}1475^{\circ}C$ but decreased at the temperatures above $1475^{\circ}C$. And the bulk density, dielectric constant and quality factor of the $Ba_5Nb_4O_{15}$ ceramics were increased in as the sintering temperature increases from $1325^{\circ}CP{\sim}1400^{\circ}C$ but decreased at the temperatures above $1400^{\circ}C$. In the case of the $Ba_5Ta_4O_{15}$ sintered at $1475^{\circ}C$ and $Ba_5Nb_4O_{15}$ ceramics sintered at $1400^{\circ}C$, the dielectric constant, quality factor, and temperature coefficient of the resonant frequency (TCRF) were 25.15, 53,105 GHz, -3.06 $ppm/^{\circ}C$ and 39.55, 28,052 GHz, +5.7 ppm/$^{\circ}C$, respectively.

• 대한의생명과학회지
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• 제29권3호
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• pp.190-200
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• 2023

Skeletal muscle, essential for metabolism, thermoregulation, and immunity, undergoes myogenic differentiation that results in myotube formation. Trans-anethole (TA), the major constituent in essential oil produced by anise, star anise, and fennel, whose function in skeletal muscle has not yet been elucidated. Therefore, we investigated whether TA influenced muscle differentiation in mouse C2C12 myoblasts. Cells were induced to differentiate using a differentiation medium with or without TA (50 or 200 mg/mL) daily for 5 days. We measured myotube length and diameter after differentiation days 1, 3, and 5 and analyzed the expression of myogenic markers (myoblast determination protein 1, myogenin, myocyte enhancer factor 2, muscle creatine kinase, and myosin heavy chain) and atrophy-related genes (atrogin-1 and muscle ring finger-1 [MuRF-1]) using quantitative real-time PCR. Additionally, we observed the expression of total protein kinase B (Akt) and phosphorylated Akt (p-Akt) using western blotting. Our data showed that TA significantly induced the formation of smaller and thinner myotubes and reduced the myogenic factor expression. Furthermore, the atrogin-1 and MuRF-1 expression markedly increased by TA. Consistent with these findings, TA significantly decreased the expression of total Akt and p-Akt. Taken together, these results indicate that TA inhibits myogenic differentiation of C2C12 cells via reduction of both total Akt and p-Akt. Our findings may provide valuable insights into the impact of PAA on individuals at risk of muscle atrophy.

• 한국재료학회지
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• 제4권8호
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• pp.855-860
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• 1994

Polycide구조로서의 Ta-silicide박막을 제작하고 Polysilicon기판에 주입된 불순물 양의 변화가 Ta-silicide형성에 미치는 영향을 조사하였다. RTA처리시 Ta silicide상은 불순물 양의 증가($1 \times 10^{13}\to 5 \times 10^{15}$/ions/$\textrm{cm}^2$)에 관계없이 $800^{\circ}C$에서 형성되기 시작하여 $1000^{\circ}C$이후 안정한 silicide박막을 형성하였다. 그러나 XRD분석결과 불순물 양이 증가할수록 Ta-silicide상의 intensity는 감소하는 경향을 나타내었고 또 SEM(cross sectional view)분석결과 silicide 형성초기온도인 $800^{\circ}C$에서는 불순물 양이 많은 시편에서 silicidation이 활발히 진척되지 못하였음을 관찰할 수 있었다. 이후 열처리 온도가 증가하면서 이러한 차이는 적어져 $1000^{\circ}C$에서는 불순물의 증가에 따른 영향이 미세해짐을 알 수 있었다. 따라서 주입된 불순물 양의 증가($1 \times 10^{13}\to 5 \times 10^{15}$/ions/$\textrm{cm}^2$)는 Ta-silicide형성시 고온에서는 큰 영향을 미치지 못하나 silicide형성초기온도에서 silicidation을 감소시키는 것으로 생각된다.