• 제목/요약/키워드: barrier function

검색결과 593건 처리시간 0.036초

복합방진벽에 의한 Rayleigh파의 차단 (Screening of Rayleigh Waves by Composite Barriers)

  • 이종세
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 1997년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 1997
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    • pp.133-140
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    • 1997
  • Based on the Green's function technique, an analytical approach is developed to examine the surface wave screening effectiveness of composite wave barriers. The composite barrier consists of a high velocity layer sandwiched between two thin layers of low shear velocity materials. The high velocity layer is represented by differential matrix operators which relate the wave fields on each side of the layer. The low velocity layers are modeled by non-rigid contact conditions which allow partial sliding at the interfaces. Screening ratio of barriers with various combination of material, geometric, and non-rigidness parameters are compared and discussed in some detail.

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콘크리트 이음부 균열의 형태에 따른 레이더 신호해석 및 검출특성 (Radar Signal Analysis of Joint Cracks in Concrete Using Radar)

  • 박석균;임영수;차은용
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2000년도 가을 학술발표회 논문집(II)
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    • pp.1309-1312
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    • 2000
  • Joints created with concrete construction result in serious weakness from the aspects of both structural and water-barrier function. Several case studies for the inspection of construction joints of column in concrete structure using radar. An analysis method based on radar signal processing using convolution technique is carried out with various patterns of joints in concrete. The computed results were verified by comparing the test results. As a result, radar signal analysis proposed in this study has a possibility of estimating patterns of joints with good accuracy.

The Determination of Interconversion Barrers of Oxygen-Containing Cyclohexene Analogues

  • 주재범;이수노;이국행
    • Bulletin of the Korean Chemical Society
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    • 제17권1호
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    • pp.7-11
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    • 1996
  • The interconversion barriers between two twisted conformers of four oxygen-containing cyclohexene analogues have been investigated utilizing a periodic hindered pseudorotational model, molecular mechanics (MM3) calculations, and previously reported far-infrared spectra. The six-fold pseudorotational potential energy function satisfactorily fits the observed bending transitions. The interconversion barrier heights calculated from the pseudorotational model show excellent agreement with those determined from two-dimensional potential energy surfaces for the ring-bending and ring-twisting vibrations. The barriers to interconversion range from 3350 $cm^{-1}$ (9.6 kcal/mol) to 3890 $cm^{-1}$ (11.1 kcal/mol) for four oxygen-containing cyclohexene analogues.

Evaluation of Microcanonical Rate Constants by Semiclassical Boundary Conditions : Early Asymptotic Analysis

  • Sungyul Lee
    • Bulletin of the Korean Chemical Society
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    • 제13권5호
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    • pp.538-541
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    • 1992
  • An approximate scheme for evaluating total reaction probability is proposed. Semiclassical boundary conditions are imposed well before the asymptotic region in the reactant and product channels to calculate the Green's function and its derivatives. Propagations are confined to a limited regime near the activated complex. Calculations are made for one dimensional Eckart barrier model of H + $H_2$ reaction. Implications of the procedure in multi-dimensional systems are discussed.

Genetic Basis of Steroid Resistant Nephrotic Syndrome

  • Park, Eujin
    • Childhood Kidney Diseases
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    • 제23권2호
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    • pp.86-92
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    • 2019
  • Steroid-resistant nephrotic syndrome (SRNS) has long been a challenge for clinicians due to its poor responsiveness to immunosuppressants, and rapid progression to end-stage renal disease. Identifying a monogenic cause for SRNS may lead to a better understanding of podocyte structure and function in the glomerular filtration barrier. This review focuses on genes associated with slit diaphragm, actin cytoskeleton, transcription factors, nucleus, glomerular basement membrane, mitochondria, and other proteins that affect podocyte biology.

Effects of pegylation on physical and biological activities of N-acetylphytosphingosine, a short chain phytoceramide

  • Park, J. H.;Park, C. Y.;Y. A. Hwang;Kim, E. J.;Kim, J. W.;Park, C. S.
    • 대한화장품학회:학술대회논문집
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    • 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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    • pp.498-498
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    • 2003
  • Sphingolipids are important structural components of the stratum corneum lipids and serve the epidermal permeability barrier function. Recent investigations on biological activities of sphingolipids have revealed that they have a number of important biological functions in the cell such as cell proliferation and differentiation, anti-inflammation, mediation of signal transduction and many more.(omitted)

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Comparison of Transfer Function Method and Reverberation Room Method in Measuring the Sound Absorption Coefficient of Rice Straw Particle Mat

  • Kang, Chun-Won;Jang, Eun-Suk;Jang, Sang-Sik;Kang, Ho-Yang
    • Journal of the Korean Wood Science and Technology
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    • 제46권4호
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    • pp.362-367
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    • 2018
  • This study estimates the sound absorption capability of rice straw particle mats by two methods: the transfer function method and the reverberation room method. In the reverberation method, the central frequency was set to the one-third octave band in the 100-5000 Hz range; in the transfer function method, the frequency range was 500-6400 Hz. Both methods yielded similar noise reduction coefficients of the rice straw mats. The noise reduction coefficient was approximately 0.8, indicating a high sound-absorption property of the mats. Therefore, rice straw matting is a suitable candidate material for sound-barrier walls against highway noise.

3-D Simulation of Nanoscale SOI n-FinFET at a Gate Length of 8 nm Using ATLAS SILVACO

  • Boukortt, Nour El Islam;Hadri, Baghdad;Caddemi, Alina;Crupi, Giovanni;Patane, Salvatore
    • Transactions on Electrical and Electronic Materials
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    • 제16권3호
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    • pp.156-161
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    • 2015
  • In this paper, we present simulation results obtained using SILVACO TCAD tools for a 3-D silicon on insulator (SOI) n-FinFET structure with a gate length of 8 nm at 300K. The effects of variations of the device’s key electrical parameters, such as threshold voltage, subthreshold slope, transconductance, drain induced barrier lowering, oncurrent, leakage current and on/off current ratio are presented and analyzed. We will also describe some simulation results related to the influence of the gate work function variations on the considered structure. These variations have a direct impact on the electrical device characteristics. The results show that the threshold voltage decreases when we reduce the gate metal work function Φm. As a consequence, the behavior of the leakage current improves with increased Φm. Therefore, the short channel effects in real 3-D FinFET structures can reasonably be controlled and improved by proper adjustment of the gate metal work function.

$ZrO_2$ 절연막을 이용한 Ta-Mo 합금 MOS 게이트 전극의 특성 (MOS characteristics of Ta-Mo gate electrode with $ZrO_2$)

  • 안재홍;김보라;이정민;홍신남
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.157-159
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    • 2005
  • MOS capacitors were fabricated to study electrical and chemical properties of Ta-Mo metal alloy with $ZrO_2$. The work function of Ta-Mo alloy were varied from 4.1eV to 5.1eV by controlling the composition. When the atomic composition of Mo is 10%, good thermal stability up to $800^{\circ}C$ was observed and work function of MOS capacitor was 4.1eV, compatible for NMOS application. But pure Ta exhibited very poor thermal stability. After $600^{\circ}C$ annealing, equivalent oxide thickness of tantalum gate MOS capacitor was continuously decreased. Barrier heights of Ta-Mo alloy and pure metal that supported the work function values were calculated from Fowler-Nordheim analysis. As a result of these electrical?experiments, Ta-Mo metal alloy with $ZrO_2$ is excellent gate electrode for NMOS.

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Emodin의 항염 및 피부장벽개선 활성 연구 (Emodin Studies on Anti-inflammatory and Skin Barrier Improvement Activities)

  • 김세기;최재근;장영아
    • 한국응용과학기술학회지
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    • 제38권6호
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    • pp.1383-1392
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    • 2021
  • 호장근, 적하수오, 대황, 알로에 등과 같은 생약재의 주요 약리 활성 성분인 emodin은 항산화, 항균, 항염, 항암, 간보호 등에 효능이 있는 것으로 보고되었다. 본 연구에서는 emodin의 피부 질환 및 기능성 소재로서의 활용 가능성을 알아보기 위해 염증 개선과 피부장벽기능 개선 관련 활성을 확인하였다. human keratinocyte인 HaCaT 세포에 대하여 항염효과를 관찰하기 위해 cytokine억제능은 ELISA kit로, 단백질 발현은 western blot으로 확인하였다. TNF-α (10 ng/mL)/IFN-γ (10 ng/mL)로 활성화된 HaCaT 세포에서 emodin을 농도별(5, 10, 20, 40) µM로 처리한 결과 TNF-α, IL-1β 및 IL-6의 생성량은 emodin의 농도가 증가함에 따라 감소됨을 확인하였다. 염증관련 단백질인 iNOS, COX-2 발현량에 대한 실험결과에서도 emodin 20 µM 농도에서 control 대비 iNOS는 48%, COX-2는 29%가 저해됨을 확인하였다. 피부장벽기능 개선의 지표로써 filaggrin, involucrin, loricirn의 mRNA 발현 정도와 filaggrin, involucrin, loricirn의 생성량을 확인한 결과 에모딘 농도에 의존적으로 증가하는 우수한 결과가 얻어졌다. 특히 20 µM 농도에서 대조군 대비 2배의 생성량 증가를 보인 filaggrin은 천연보습인자인 NMF의 형성에 관계되는 단백질로 각질층의 보습에 중요한 역할을 하는 것으로 알려져 있다. 결론적으로 emodin의 피부 질환 및 기능성 소재로서의 활용 가능성 중 염증 개선 및 피부장벽기능 개선 소재로 활용될 수 있음을 확인하였으며 향후 추가적인 연구가 수행되면 그 활용 범위가 더 넓어질 수 있을 것으로 사료된다.