• 한국세라믹학회지
• /
• 제42권3호
• /
• pp.150-154
• /
• 2005

Ferroelectric $Bi_{3.35}Sm_{0.65}Ti_{3}O_{12}(BSmT)$ thin films were synthesized by sol-gel process. In this experiments, $Bi(TMHD)_{3},\;Sm_{5}(O^{i}Pr)_{13},\;Ti(O^{i}Pr)_4$ were used as precursors, which were dissolved in 2-methoxyethanol. The BSmT thin films were deposited on the Pt/TiO/SiO/Si substrates by spin-coating. Thereafter, the thin films with the thickness of 240 nm were annealed from 600 to $720^{\circ}C$ in oxygen atmosphere for 1 h, and post-annealed in oxygen atmosphere for 1 h after deposition of Pt electrode to enhance the electrical properties. To investigate the effects of Sm-substitution in the BTO thin films, the BTO and BSmT thin films were prepared, respectively. The remanent polarization and coercive voltage of the BSmT thin films annealed at $720^{\circ}C$ were $19.48{\mu}C/cm^2$ and 3.40 V, respectively.

• 한국재료학회지
• /
• 제18권4호
• /
• pp.169-174
• /
• 2008

The structural and electrical properties of amorphous $BaSm_2Ti_4O_{12}$ (BSmT) films on a $TiN/SiO_2/Si$ substrate deposited using a RF magnetron sputtering method were investigated. The deposition of BSmT films was carried out at $300^{\circ}C$ in a mixed oxygen and argon ($O_2$ : Ar = 1 : 4) atmosphere with a total pressure of 8.0 mTorr. In particular, a 45 nm-thick amorphous BSmT film exhibited a high capacitance density and low dissipation factor of $7.60\;fF/{\mu}m2$ and 1.3%, respectively, with a dielectric constant of 38 at 100 kHz. Its capacitance showed very little change, even in GHz ranges from 1.0 GHz to 6.0 GHz. The quality factor of the BSmT film was as high as 67 at 6 GHz. The leakage current density of the BSmT film was also very low, at approximately $5.11\;nA/cm^2$ at 2 V; its conduction mechanism was explained by the the Poole-Frenkel emission. The quadratic voltage coefficient of capacitance of the BSmT film was approximately $698\;ppm/V^2$, which is higher than the required value (<$100\;ppm/V^2$) for RF application. This could be reduced by improving the process condition. The temperature coefficient of capacitance of the film was low at nearly $296\;ppm/^{\circ}C$ at 100 kHz. Therefore, amorphous BSmT grown on a TiN substrate is a viable candidate material for a metal-insulator-metal capacitor.

• 한국버섯학회지
• /
• 제21권3호
• /
• pp.140-144
• /
• 2023

본 연구는 길항성 미생물, Bacillus subtilis BSM320을 이용한 표고 푸른곰팡이병의 생물학적 방제를 목적으로 하였다. B. subtilis BSM320는 표고 톱밥배지 에서 분리된 T. hazianum을 포함한 3 Trichoderma 분리균주 대해 균사 생장을 억제하는 항균 활성을 나타냈다. B. subtilis BSM320은 1% glucose를 포함하는 LeCSMS물 추출물(LeCSMS WE)에서 4.2 × 10⁹±113.7 cfu/mL 세균수로 고밀도 배양 되었으며 상용배지 Lurina-Bertani broth 배지보다 높은 세균 밀도를 보였다. B. subtilis BSM320의 LeCSMS WE 배양액은 표고 자실체에 약해 없이 표고 톱밥 배지에 발생하는 푸른곰팡이병에 대하여 75%의 방제효과를 보였다. 그 결과는 LeCSMS 물 추출물 배양 B. subtilis BSM320는 표고 푸른곰팡이병의 생물학적 방제에 활용할 수 있는 것을 시사한다.

• Transactions on Electrical and Electronic Materials
• /
• 제6권2호
• /
• pp.51-56
• /
• 2005

Ferroelectric Bi$_{3.35}$Sm$_{0.65}$Ti$_{3}$O$_{12}$(BSmT) thin films were synthesized using a sol-gel process. Bi(TMHD)$_{3}$, Sm$_{5}$(O$^{i}$Pr)13, Ti(O$^{i}$Pr)4 were used as the precursors, which were dissolved in 2­methoxyethanol. The BSmT thin films were deposited on Pt/TiO$_{x}$/SiO$_{2}$/Si substrates by spin­coating. The electrical properties of the thin films were enhanced using rapid thermal annealing process (RTA) at 600 $^{circ}$C for 1 min in O$_{2}$. Thereafter, the thin films were annealed from 600 to 720 $^{circ}$C in oxygen ambient for 1 hr, which was followed by post-annealed for 1 hr after depositing a Pt electrode to enhance the electrical properties. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to analyze the crystallinity and surface morphology of layered perovskite phase, respectively. The remanent polarization value of the BSmT thin films annealed at 720 $^{circ}$C after the RTA treatment was 35.31 $\mu$C/cmz at an applied voltage of 5 V.

• E2M - 전기 전자와 첨단 소재
• /
• 제10권7호
• /
• pp.674-681
• /
• 1997

Ternary compound ceramics, (1-y-x) BaTiO$_3$-y SrTiO$_3$-x MgTiO$_3$(0.00 x 0.20), were fabricated by the conventional ceramic process. The structural and dielectric properties of specimens were investigated while varying the composition and sintering temperature(1,200~1,45$0^{\circ}C$) in order to obtain the optimum condition of capacitor. As is well known, Curie temperature(T$_{c}$) of high dielectric-based ceramic(BaTiO$_3$) was shifted and temperature of capacitance was decreased in according to increase of solid solution with (Sr, Mg)TiO$_3$. As a result, a suitable condition of compound rate for capacitor was obtained such as the BSM-11(0.8BaTiO$_3$-0.1SrTiO$_3$-0.1MgTiO$_3$), and sintering temperature was sintered at 1,25$0^{\circ}C$ for two hours. In this case, dielectric constant<1,300, dielectric loss(tan$\delta$)<0.03, and the variation rate of capacitance had less than 3% in the range -10~7$0^{\circ}C$.>.

• 대한환경공학회지
• /
• 제30권4호
• /
• pp.393-400
• /
• 2008

유기용제 안정제로 사용되는 1,4-다이옥산($C_4H_8O_2$)은 높은 용해도와 독성으로 인해 생태계에 유해하며 미국 EPA 의해 발암가능성이 있는 물질로 분류되어 있다. 국내에서도 환경부에 따르면 2011년부터 수계로의 배출허용기준이 5 mg/L로 추진될 예정에 있다. 따라서 구미의 폴리에스테르 제조 공정에서 발생되는 현재 운전 중인 활성슬러지가 1,4-다이옥산을 기준에 적합하도록 적절하게 처리할 수 있는지를 조사하였다. 이와 같은 목적으로 일부 회사(K, H 및 T)를 대상으로 1,4-다이옥산의 제거율 및 미생물학적 속성이 평가되었다. 처리효율은 H사에서 98%로 가장 높았으며 K사는 77%로 두 개 사 모두 유출농도가 기준에 부합하였다. 그러나 T사 유출수의 1,4-다이옥산 농도는 23 mg/L로 기준보다 높았다. 한편, 각 업체의 활성슬러지를 100 ppm의 1,4-다이옥산이 포함된 BSM(Basal salt medium)에 식종하여 생물학적 분해실험을 수행하였다. 7일간의 운전 후, H사의 슬러지를 이용한 시험에서 1,4-다이옥산이 완전히 제거되었으며 T사는 67%, K사는 52%로 이 처리효율의 차이는 1,4-다이옥산의 양이 아닌 주어진 활성 슬러지의 생분해능이 서로 다른 것에 의한 것임을 확인할 수 있었다. 결과적으로 각 산업체의 미생물 다양성이 16s rDNA cloning 방법을 통해 조사되었으며 Methylibium petroleiphilum PM1이 H사에서 가장 많이 발견되었으며 K사에서 적은 양이, 그리고 T사에서는 발견되지 않았다. Methylibium petroleiphilum PM1은 methyl tertiary-butyl ether(MTBE)와 같은 에테르 물질을 효과적으로 제거하는 것으로 알려져 있다. 이는 산업분야의 관점에서 H사의 활성 슬러지가 1,4-다이옥산의 생분해에 가장 효과적으로 적용될 수 있다는 것을 나타낸다.

• 생물정신의학
• /
• 제10권2호
• /
• pp.133-140
• /
• 2003

Objective:Some candidate gene polymorphisms were reported to be associated with tardive dyskinesia (TD). The aim of this study was to investigate the association of the 5-$HT_{2A}$ receptor gene polymorphisms with TD in Korean schizophrenic subjects. Method:Subjects were of 59 schizophrenic patients with TD and 60 schizophrenic patients without TD for studying of 5-$HT_{2A}$ receptor gene polymorphisms. TD was evaluated using the Abnormal Involuntary Movement Scale(AIMS). Genomic DNA was amplified by PCR and digestion with MspI and BsmI. Result:There were no statistically significant differences in the demographic variables, such as age, male to female percentage, duration of illnesses and duration of antipsychotic drug exposure between the TD group and control group. 1) T102C polymorphisms and TD Comparing the TD group and control group, the 102T/C allele was associated with a significantly increased risk for TD (${\chi}^2$=5.560, df=1, p=0.018). 2) Three AIMS categories of TD and T102C genotype. There were statistically significant differences in the three AIMS categories(${\chi}^2$=6.835, df=2, p=0.033). Conclusion:These result suggest 102T/C genotypes of the 5-$HT_{2A}$ receptor gene are related to the development of TD. The 102T/C genotypes were associated with significantly higher AIMS orofacial dyskinesia scores. These findings suggest that the 5-$HT_{2A}$ receptor gene is significantly associated with susceptibility to TD in patients with chronic schizophrenia.

• 대한지역사회영양학회지
• /
• 제11권4호
• /
• pp.534-540
• /
• 2006

Recent studies have shown that environmental, biochemical, nutritional or genetic factors affect bone mineral density (BMD). The purpose of the present study was to investigate the effect of vitamin D receptor (VDR) gentotype and nutritional status on BMD of elderly women living in a rural area. Three hundred thirty five elderly women over 65 years in Asan participated the study. Data for demographic and nutrient intakes were obtained by survey with a two day 24 hr recall method. BMD was measured by broadband ultrasound attenuation (BUA) using quantitative ultrasound (QUS). VDR genotypes of the subjects analyzed with Bsm I restriction enzyme were bb (92%), Bb (7%) and BB (1%). No differences were found between genotypes bb and Bb/BB in age, menopausal age, body mass index and body fat. BUA of bb genotype was higher (62.5 $\pm$ 15.6 dB/MHz) than Bb/BB genotype (56.1 $\pm$ 17.6 dB/MHz) by Student's t-tests. Correlation analyses showed strong negative correlation of BMD and age, but positive correlation with BMI, energy and calcium intake. When subgroup analyses were conducted after stratification by the median calcium intake level (412.9 mg/d), the above median calcium intake group showed significant difference in BUA by VDR genotype while the lower median calcium intake group did not show significant difference. The current study confirmed interaction of calcium intake and VDR genotype in association with BMD. Further nutritional intervention will be needed to improve calcium status of the elderly women living in rural areas.

• Tuberculosis and Respiratory Diseases
• /
• 제45권3호
• /
• pp.529-535
• /
• 1998

연구배경: IL-4는 기관지천식의 병인에 중요한 역할을 하는 cytokine으로서 B세포에서 IgE를 생성하게 하여 아토피의 발생에 중요한 역할을 한다. IL-4의 유전자 다형에 관한 연구로 promoter부위 (-589) 에 cytosine이 thymine으로 치환되는 polymorphism(-589 C$\rightarrow$T polymorphism) 이 존재한다는 것이 밝혀졌다. 그 후 IL-4 유전자 polymorphism이 천식 환자에 어떤 영향을 미치는 지에 대한 연구가 진행되어 왔다. 본 연구에서는 polymorphism이 IL-4 유전자의 발현을 조절하는 promoter에 위치하므로 혈액내 IgE level에 영향을 주어 증상의 정도에 관여할 것이라는 가정하에 천식 환자의 증상의 정도와 IL-4 유전자 다형과의 연관성을 조사하였다. 또한 한국의 천식환자에서의 이러한 유전자 다형의 유형과 빈도를 조사하였다. 방 법: 고려대학교 부속병원에 내원한 49명의 천식환자와 33명의 정상 대조군을 대상으로 하였다. 모든 천식 환자는 증상의 정도에 따라 경증, 중등증 및 중증의 두 대상군으로 나누었다. 모둔 천식 환자와 정상인의 혈액에서 DNA를 분리하였고 ARMS(Amplification Refractory Mutation System) 및 RFLP(Restriction Fragment Length Polymorphism)를 시행하여 polymorphism의 존재 및 유형을 검색하였다. 결 과: 천식 환자의 중상의 정도와 IL-4 유전자 다형의 유형과는 유의한 관계를 발견할 수 없었다 (P=0.709). 정상인이나 천식환자에서 polymorphism(C/T 및 T/T형)의 빈도가 각각 100% 와 95.9%로 서양보다 월등히 높았다. 그러나 두 군에서 polymorphism의 유형 및 그 빈도에 있어서 차이는 없었다. 33명의 정상 대조군에서는 C/C형을 발견할 수 없었고, 정상인과 천식환자에서 공히 T/T형이 C/T형보다 약간 많은 빈도를 보였다. 결 론: IL-4 유전자의 -589 C/T polymorphism과 천식 환자의 증상의 경중과는 유의한 연관성을 발견하지 못했다. 그러나 우리나라 천식 환자와 정상인에서 서양보다 월등히 많은 수에서 polymorphism을 관찰할 수 있었으며, 정상인에서는 C/C 형이 발견되지 않았다. 따라서 IL-4 유전자 다형성이 종족간에 현저한 차이를 보일 수 있다는 결론을 얻을 수 있었다.

• 대한치과기공학회지
• /
• 제33권4호
• /
• pp.349-357
• /
• 2011

Purpose: In this study, for the reasons of observing the changes when using bonding agent with Ni-Cr alloy and Co-Cr alloy and using VM13 and Vintage MP ceramic which have the disparity in coefficient of thermal expansion, it is carried out to evaluate the characteristics of the bonding agent through the analysis of the interface between metal and ceramic and the analysis of bond strength by variable. Methods: The surface treatment was performed on the two kinds of alloy(Ni-Cr alloy and Co-Cr alloy) specimens, which were sandblasted and were treated with bonder application. The metal-ceramic interfaces were analyzed with EPMA in order to ionic diffusion, and the shear test was performed. Results: As a result of observation of metal-ceramic interfacial properties, it was observed that Cr atoms were spread from the alloy body to the ceramic floor in the specimen of Group B. It was also seen that Cr, W atoms were spread from the alloy body to the ceramic floor in the specimen of Group S. In consequence of observing Shear bond strength, it was calculated that the specimen of BSV was 27.75(${\pm}11.21$)MPa, BSM was 27.02(${\pm}5.23$)MPa, BCV was 30.20(${\pm}5.99$)MPa, BCM was 27.94(${\pm}10.76$)MPa, SSV was 20.83(${\pm}2.58$)MPa, SSM was 23.98(${\pm}3.94$)MPa, SCV was 32.32(${\pm}4.68$)MPa, and SCM was 34.54(${\pm}10.63$)MPa. Conclusion: In the metal-ceramic interface of Bellabond plus sample group, diffusion of Cr atoms was incurred and diffusion of C Cr atoms and W atoms in the sample group of $Starloy{(R)}\;C$ was observed. Using bonding agent showed the higher bond strength than using the sand blasting treatment. In the Bellabond plus alloys, the specimen group with the use of binding materials showed higher shear bond strength, but didn't show statistically significant differences (p>0.05). In the $Starloy{(R)}\;C$ alloys, the specimen group with the use of binding materials showed higher shear bond strength and statistically significant differences(p<0.05). In terms of VM13 ceramic, it was in the Bellabond plus alloys that the high shear bond strength was showed, but there's no statistically significant differences(p>0.05). In terms of Vintage MP ceramic, it was in the $Starloy{(R)}\;C$ alloys that the high shear bond strength was showed and statistically significant differences(p<0.05). Metal-ceramic to fracture of the shear strength measurements and an analysis of all aspects of military usage fracture of the composite, respectively.