• Title/Summary/Keyword: SBT

Search Result 197, Processing Time 0.02 seconds

Effects of Sambutang and Consitituent Herbs on the Regional Cerebral Blood Flow and Mean Arterial Blood Pressure in Rats (삼부탕(蔘附湯) 및 구성약물(構成藥物)이 백서(白鼠)의 국소뇌혈류량(局所腦血流量)과 혈압(血壓)에 미치는 영향(影響))

  • Hong Seok;Kang Hwa-Jung;Kim Kyung-Seon;Kim Kyung-Su;Jeon Hong-Yeol
    • Herbal Formula Science
    • /
    • v.10 no.1
    • /
    • pp.93-103
    • /
    • 2002
  • This experimental studies were done to investigate the effects of Sambutang(SBT) and consitituent herbs on the regional cerebral blood flow(rCBF) and mean arterial blood pressure(BP) in rats. The results are as follows: SBT and consitituent herbs(SBT omitting Zingiberis Rhizoma Recens, Zingiberis Rhizoma Recens. Ginseng Radix and Aconiti iateralis preparata Radix) was increased rCBF significantly in a dose-dependent manner. SBT omitting Zingiberis Rhizoma Recens and Ginseng Radix were decreased significantly BP in rats. But, SBT, Aconiti iateralis preparata Radix and Zingiberis Rhizoma Recens were not affected BP in rats. According to the above findings. it is suggested that SBT causes a diverse response of rCBF, and specially the rCBF by increasing SBT is mediated action of Zingiberis Rhizoma Recens.

  • PDF

Microstructure and Electric Properties of Ferroelectric SrBi$_2$Ta$_2$O$_9$ Thin Films Deposited by Modified Rf Magnetron Sputtering Technique (Modified Rf Magnetron Sputtering에 의해 Pt/Ti/SiO$_2$/Si 기판위에 제조된 강유전체 SrBi$_2$Ta$_2$O$_9$ 박막의 미세구조 및 전기적 특성 연구)

  • 양철훈;윤순길
    • Journal of the Korean Ceramic Society
    • /
    • v.35 no.5
    • /
    • pp.472-478
    • /
    • 1998
  • Ferroelectric SrBi2Ta2O9(SBT) films were deposited on Pt/Ti/SiO2/Si substrates at 50$0^{\circ}C$ using a sintered SBT target Bi and Ta targets by modified rf magnetron sputtering and then were annealed at 80$0^{\circ}C$ for 10min in oxygen ambinet(760 torr) The composition of the SBT films could be easily controlled using the mul-ti-targets. The film composition of {{{{ {Sr }_{0.8 } {Bi }_{2.9 } {Ta}_{2.0 } {O }_{9 } }} was obtained with SBTd sputtering power of 100 W Bi of 25W and Ta of 10 W. A 250nm thick SBT films exhibited a dense and uniform microstructure and showed the remanent polarization(Pr) of 14.4 $\mu$C/cm2 and the coercive field({{{{ {E }_{c } }})of 60 kV/cm at applied voltage of 5 V. The SBT films show practically no polarization fatigue up to {{{{ {10 }_{10 } }} cycles under 5V bipolar pulse. The retention characteristics of the SBT films looked very promising and the leakage current density of the SBT films was about 1.23$\times${{{{ {10 }^{-7 } }}A/c{{{{ {m }^{2 } }} at 120kV/cm.

  • PDF

Structural and Electrical Characteristics of the SBT Thin Films Prepared by PLD Method (PLD법에 의해 제조된 SBT 박막의 구조 및 전기적 특성)

  • 마석범;오형록;김성구;장낙원;박창엽
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.13 no.1
    • /
    • pp.66-74
    • /
    • 2000
  • The structural and electrical characteristics of SBT thin films, fabricated on Pt/Ti/SiO\ulcorner/Si substrates by a pulsed laser deposition(PLD), were investigated to develop ferroelectric thin films for capacitor lay-ers of FRAM. EFfects of target composition on the characteristics of SBT thin films were examined. Target were prepared by mixed oxide method, and composition of Sr/Bi/Ta on SBT was changed to 1/2/2, 1/2.4/2, 1/2.8/2, 0.8/2/2 and 1.2/2/2. SBt thin films were fabricated, as a function of substrate temperature and oxygen pressure, by PLD. The optimized ocndition, to fabricate high quality SBT thin films, was 700 $^{\circ}C$ of substrate temperature, 200 mTorr of oxygen pressure, and 2 J/$\textrm{cm}^2$ of laser energy density. Maximum remnant value(2Pr) of 9.0 $\mu$C/$\textrm{cm}^2$, coercive field value(Ec) of 50 kV/cm, dielectric constant value of 166, and leakage current densities of <10\ulcorner A/$\textrm{cm}^2$ were observed for the films with 1/2/2 composition, which was prepared at the above PLD condition.

  • PDF

Electrical properties of S$SrBi_{2x}Ta_2O_9$ thin films with Bi content (Bi 함량에 따른 $SrBi_{2x}Ta_2O_9$ 박막의 전기적 특성)

  • 연대중;권용욱;박주동;오태성
    • Journal of the Korean Vacuum Society
    • /
    • v.8 no.3A
    • /
    • pp.224-230
    • /
    • 1999
  • $SrBi_{2x}Ta_2O_9$ (SBT) thin films were prepared on platinized silicon substrates by MOD process, and their ferroelectric and leakage current characteristics were investigated. The grain size of the MOD derived SBT films increased with increasing the BI/Ta mole ration. Although the SBT films with x of 0.8~1.2 were composed of the equiaxed grains, the elongated grains were also observed for the SBT films with x of 1.4 and 1.6. The SBT film with x of 1.2 exhibited the optimum ferroelectric properties of 2PR : 9.79 $\muC/\textrm{cm}^2$ and Ec : 24.2kV/cm at applied voltage of 5V. The leakage current density of the SBT films increased with increasing the BI/Ta mole ratio. With post annealing process, 2Pr and $E_c$of the SBT film with x of 1.2 increases 11.3 $\muC/\textrm{cm}^2$ and 39.6kV/cm, respectively. decrement of the leakage current density by post annealing process increased remarkably with increasing the Bi/ta mole ratio, and the SBT film with x=1.6 exhibited the lowest leakage current density after post annealing process.

  • PDF

Risk factors of chronic subscapularis tendon tear

  • Hyung Bin Park;Ji Yong Gwark;Jae-Boem Na
    • Clinics in Shoulder and Elbow
    • /
    • v.25 no.4
    • /
    • pp.257-264
    • /
    • 2022
  • Background: Chronic subscapularis tendon tear (SBT) is a degenerative disease and a common pathologic cause of shoulder pain. Several potential risk factors for chronic SBT have been reported. Although metabolic abnormalities are common risk factors for degenerative disease, their potential etiological roles in chronic SBT remains unclear. The purpose of this study was to investigate potential risk factors for chronic SBT, with particular attention to metabolic factors. Methods: This study evaluated single shoulders of 939 rural residents. Each subject undertook a questionnaire, physical examinations, blood tests, and simple radiographs and magnetic resonance imaging (MRI) evaluations of bilateral shoulders. Subscapularis tendon integrity was determined by MRI findings based on the thickness of the involved tendons. The association strengths of demographic, physical, social, and radiologic factors, comorbidities, severity of rotator cuff tear (RCT), and serologic parameters for SBT were evaluated using logistic regression analyses. The significance of those analyses was set at p<0.05. Results: The prevalence of SBT was 32.2% (302/939). The prevalence of partial- and full-thickness tears was 23.5% (221/939) and 8.6% (81/939), respectively. The prevalence of isolated SBT was 20.2% (190/939), SBT combined with supraspinatus or infraspinatus tendon tear was 11.9% (112/939). In multivariable logistic regression analysis, dominant side involvement (p<0.001), manual labor (p=0.002), diabetes (p<0.001), metabolic syndrome (p<0.001), retraction degree of Patte tendon (p<0.001), posterosuperior RCT (p=0.010), and biceps tendon injury (p<0.001) were significantly associated with SBT. Conclusions: Metabolic syndrome is a potential risk factor for SBT, as are these factors: overuse activity, diabetes, posterosuperior RCT, increased retraction of posterosuperior rotator cuff tendon, and biceps tendon injury.

A study on the characteristics of MEM structure of $SrBi_2Ta_2O_9$ thin films by RE magnetron sputtering (RF 마그네트론 스퍼터링법에 의한 MFM 구조의 $SrBi_2Ta_2O_9$ 박막 특성에 관한 연구)

  • 이후용;최훈상;최인훈
    • Journal of the Korean Vacuum Society
    • /
    • v.9 no.2
    • /
    • pp.136-143
    • /
    • 2000
  • $SrBi_2Ta_2O_9;(SBT)$ films were deposited on p-type Si(100) at room temperature by rf magnetron sputtering method to confirm the possibility of application of $Pt/SBT/Pt/Ti/SiO_2/Si$ structure (MFM) for destructive read out ferroelectric RAM (random access memory). Their structural characteristics with the various annealing times and Ar/$O_2$ gas flow ratios in sputtering were observed by XRD (X-ray diffractometer) and the surface morphologies were observed by FE-SEM (field emission scanning electron microscopy), and their electrical properties were observed by P-V (polarization-voltage measurement) and I-V (current-voltage measurement). The Ar/$O_2$ gas flow ratios of sputtering gas were changed from 1 : 4 to 4 : 1 and SBT thin films were deposited at room temperature. The films show (105), (110) peaks of SBT by XRD measurement. SBT thin films deposited at room temperature were crystallized by furnace annealing at 80$0^{\circ}C$ in oxygen atmosphere during either one hour or two hours. Among their electrical properties, P-V curves showed shaped hysteresis curves, but the SBT thin films showed the asymmetric ferroelectric properties in P-V curves. When Ar/$O_2$ gas flow ratios are 1 : 1, 2: 1, the leakage current density values of SBT thin films are good, those values of 3 V, 5 V, and 7 V are respectively $3.11\times10^{-8} \textrm{A/cm}^2$, $5\times10^{-8}\textrm{A/cm}^2$, $7\times10^{-8}\textrm{A/cm}^2$.After two hours of annealing time, their electrical properties and crystallization are improved.

  • PDF

Leakage Current Properties of SBT Capacitors with various Annealing Atmosphere (다양한 열처리 분위기에 따른 SBT 커패시터의 누설전류 특성)

  • Cho, Choon-Nam;Oh, Young-Choul;Kim, Jin-Sa;Shin, Cheol-Gi;Choi, Woon-Shik;Kim, Chung-Hyeok;Hong, Jin-Woong;Lee, Joon-Ung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2003.05d
    • /
    • pp.77-81
    • /
    • 2003
  • The $Sr_{0.7}Bi_{2.6}Ta_2O_9$(SBT) thin films are deposited on Pt-coated electrode(Pt/$TiO_2/SiO_2$/Si) using RF magnetron sputtering method. The structural and electrical properties of SBT capacitors were influenced with annealing atmosphere. In the XRD pattern, the SBT thin films in all annealed atmosphere had (105) orientation. In the SEM images, Bi-layered perovskite phase was crystallized in all annealing atmosphere and grains largely grew in oxygen annealing atmosphere. The dielectric constant and leakage current density of capacitors annealed oxygen atmosphere are 340 and $2.13{\times}10^{-9}[A/cm^2]$ respectively.

  • PDF

Dry etching properties of SBT thin films using $Cl_2/Ar$ inductively coupled plasma ($Cl_2/Ar$ 유도결합 플라즈마를 이용한 SBT 박막의 건식 식각 특성)

  • Yeo, Ji-Won;Kim, Kyoung-Tae;Kim, Dong-Pyo;Kim, Chang-Il
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2003.07a
    • /
    • pp.404-407
    • /
    • 2003
  • Among the ferroeletric thin films that have been widely investigated for ferroelectric random access memory (FRAM) applications, the $SrBi_2Ta_2O_9$ (SBT) thin film is appropriate as a memory capacitor material due to its excellent fatigue endurance. SBT thin films were etched in high-density $Cl_2/Ar$ in inductively coupled plasma. The maximum etch rate of SBT film is $1834\;{\AA}/min$ under $Cl_2/(Cl_2+Ar)$ of 30 %, rf power of 700 W, dc-bias voltage of -250 V, chamber pressure of 11 mTorr and gas flow rate of 20 sccm.

  • PDF

Etching Characteristics of SBT Ihin Film in High Density Plasma (고밀도 플라즈마를 이용한 SBT의 식각 특성)

  • 김동표;이원재;유병곤;김창일
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2000.07a
    • /
    • pp.938-941
    • /
    • 2000
  • SrBi$_2$Ta$_2$$O_{9}$(SBT) thin films were etched in Ar/SF$_{6}$ and Ar/CHF$_3$gas plasma using magnetically enhanced inductively coupled plasma(MEICP) system. The etch rates of SBT thin film were 1500$\AA$/min in SF$_{6}$/Ar and 1650 $\AA$/min in Ar/CHF$_3$at a rf power of 600W a dc-bias voltage of -l50V. a chamber pressure of 10 mTorr. In order to examine the chemical reactions on the etched SBT thin film surface , x-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS) were examined. In etching SBT thin film with F-base gas plasma, M(Sr. Bi. Ta)-O bonds are broken by Ar ion bombardment and form SrFand TaF$_2$ by chemical reaction with F. SrF and TaF$_2$are removed more easily by Ar ion bombardmentrdment

  • PDF

Effect of Sr/Ta mole ratio on the ferroelectric properties of SBT thin films fabricated by LSMCD process (LSMCD 공정으로 제조한 SBT 박막의 Sr/Ta 몰비에 따른 강유전 특성)

  • 박주동;김지웅;오태성
    • Journal of the Korean Vacuum Society
    • /
    • v.9 no.4
    • /
    • pp.360-366
    • /
    • 2000
  • $Sr_xBi_{2.4}Ta_2O_9$ (SBT) thin films of 150 nm thickness were prepared using LSMCD (Liquid Source Misted Chemical Deposition) process with variation of the Sr/Ta mole ratio of 0.35~0.65, and their crystalline phase, microstructure, ferroelectric properties and leakage current characteristics were investigated. Ferroelectric characteristics of the LSMCD-derived SBT films were optimized at the Sr/Ta moleratio of 0.425. The remanent polarization (2Pr) and coercive field (Ec) of the SBT film with the Sr/Ta mole ratio of 0.425 were measured as 15.01 $\mu$C/$ \textrm{cm}^2$ and 41 kV/cm at an applied voltage of $\pm$5 V respectively. LSMCD-derived SBT films with the Sr/Ta mole ratio of 0.35~0.5 exhibited leakage current densities lower than $10^{-5} A/\textrm{cm}^2$ at an applied field of 100 kV/cm, and excellent fatigue-free characteristics of the remanent polarization decrement less than 1% after $10^{10}$ switching cycles at$\pm$5 V.

  • PDF