• Title/Summary/Keyword: Gap times

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Lack of connexin 32 does not enhance the benzene-induced hematotoxicity and hemopoietic tumor incidence in mice

  • Yoon, Byung-IL
    • 대한수의학회지
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    • 제45권4호
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    • pp.517-525
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    • 2005
  • This study was performed to evaluate using wild-type (WT) and $C{\times}32$ knockout (KO) mice if lack of cell to cell communication by connexin 32 gap junction enhances the benzene-induced hematotoxicity and hemopoietic tumor development. The WT and $C{\times}32$ KO mice were exposed to 300 ppm of benzene for 6 hours/day, 5 days/week for a total of 26 weeks by inhalation, and then sacrificed to evaluate the toxicities of hemopoietic organs or allowed to live out their life span to evaluate the hemopoietic tumor incidence. The significant increase and decrease of organ weight were respectively noted in spleen and thymus of both WT and $C{\times}32$ KO mice without significant difference between the genotypes. Histopathologically, benzene exposure for 26 weeks induced the morphological changes in hemopoietic organs, characterized by fat cell accumulation in the bone marrow and extramedullary hemopoiesis in the spleen. The fat cell accumulation was, compared with that of WT mice, considerably exacerbated in the $C{\times}32$ KO mice. However, no significant difference was observed in the changes of hematological values and bone marrow cellularity as well as in the onset and incidence of hemopoietic tumors between WT and $C{\times}32$ KO mice. In conclusion, this study indicated little significant role of the cellular communication by $C{\times}32$ gap junction in the action mechanism of benzene hematotoxicity and leukemogenicity.

표면 탄성파 장치에 기반한 무선 간극 센서 (Wireless Gap Sensor Based on Surface Acoustic Wave Device)

  • 김재근;박경수;박노철;박영필;이택주;임수철;엄원석
    • 한국소음진동공학회논문집
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    • 제21권3호
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    • pp.206-211
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    • 2011
  • In this paper, we report a high-precision wireless gap sensor based on a surface acoustic wave (SAW) device. The sensing element is a parallel-plate capacitor whose dimensions are $3{\times}3\;mm^2$, and is attached to the SAW device as an external load. The SAW device, equipped with an RF antenna, serves simultaneously as a signal conditioner and an RF transponder. The center frequency of the SAW device is 450 MHz. The wireless gap sensor prototype exhibits a resolution of 100 nm and a sensing range of $50{\mu}m$. The proposed sensor system can be used for remote, high-precision gap measurement in hard-to-reach environments.

Measurement of Refractive Index of Solid Medium by Critical Angle Method When Air Gap is Present

  • Lim, Hwan-Hong;Kwon, Moon-Soo;Choi, Hee-Joo;Kim, Byoung-Joo;Cha, Myoung-Sik
    • Journal of the Optical Society of Korea
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    • 제12권3호
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    • pp.210-214
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    • 2008
  • A critical angle method was used to measure the index of refraction of a solid medium when an air gap between the prism and the medium is present. The gap effect was analyzed both numerically and experimentally. Since the total internal reflection is severely disturbed by the large gap, determination of the critical angle and the resulting refractive index becomes ambiguous and inaccurate. By using an index matching fluid, we could determine the index of refraction with an uncertainty of ${\pm}2{\times}1^{-3}$ even when the gap is as large as 1 ${\mu}m$.

평행한 두 사각유로를 연결하는 협소유로내의 난류유동 특성에 관한 대형 와 수치 모사 (Numerical Investigation on Turbulent Flow Characteristics in the Gap connecting with Two parallel Channels using Large Eddy Simulation)

  • 홍성호;서정식;신종근;최영돈
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2008년도 동계학술발표대회 논문집
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    • pp.55-60
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    • 2008
  • Turbulent flow characteristics on the gap of two parallel channels are investigated using LES(large eddy simulation) approach. Two parallel channels have the same cross-section area and are connected by the narrow channel named the gap. Turbulent flow near the gap makes the flow pulsation along the streamwise direction of two channels. The flow condition is the Reynolds number of $2.5{\times}10^{-5}$. We compared the predicted results with the previous experimental results and presented the axial mean velocity, turbulent intensities, Reynolds shear stresses and turbulent kinetic energy.

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Electrochemical Signal Amplification by Redox Cycling in Distance-Controlled Nanogap Devices

  • Park, Dae Keun;Park, Jong Mo;Shin, Jong-Hwan;Yun, Wan Soo
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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    • pp.269-269
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    • 2013
  • Redox cycling in between the two working electrodes in an electrochemical cell can lead a great signal enhancement. In this work, we report on a systematic examination of current amplification along with the decrease in the gap distance of a nanogap device which was fabricated by the combination of photo and chemical lithography [1]. The gap distance was controlled by the chemical lithographic process of surfacecatalyzed growth of metallic layer on pre-defined electrodes with wider initial gap. Enhancement of the redox current of ferri/ferrocyanide was observed upon gap distance reduction and the current is amplified about a thousand times in this redox system when the gap distance was decreased from 200 nm to 30 nm. The experimental results were discussed on the basis of the cyclic voltammetry (CV), atomic force microscopy (AFM) and scanning electron microscopy (SEM).

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Electrochemical Signal Amplification by Gap Electrodes and Control of Gap Distances

  • Park, Dae Keun
    • KEPCO Journal on Electric Power and Energy
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    • 제5권3호
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    • pp.197-200
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    • 2019
  • We report on electrochemical signal amplification using gap electrodes based on the redox cycling between gap electrodes. The distance between electrodes was controlled from $2{\mu}m$ to a few hundreds of nanometer by chemical deposition of reduced Au ion on the pre-defined electrodes. Enhanced redox current of ferri/ferrocyanide was obtained by redox cycling between the two working electrodes. The faradaic current is amplified about a thousand times in this redox system. Since the signal amplification is due to the shortened diffusion length between the two electrodes, the narrower the nanogap was, the better detection limit, calibration sensitivity, and dynamic range. The experimental results were discussed on the basis of the cyclic voltammetry (CV), atomic force microscope (AFM) and scanning electron microscope (SEM) measurements.

X선조사(線照射)에 의한 절연유(絶緣油)의 도전특성(導電特性)에 관한 연구(硏究) (A Study on Conductivity Characteristics of X-ray Irradiated Insulating Oil)

  • 김영일;이덕출;정연택
    • 대한방사선기술학회지:방사선기술과학
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    • 제10권1호
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    • pp.75-83
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    • 1987
  • The insulating oil used for X-ray tube housing were degraded by X-ray irrdiation, high temperature and high anode voltage for normal operation. This study was measured the conduction current-X-ray dose, heating degradation, time, temperature and electric field characteristics and the dependense of electrode materials and gap length in the X-ray irradiatied insulating oil under of D.C voltage. The obtained results can be summarized as following. 1. The conduction current of X-ray irradiated insulating oil is more about $2.5{\sim}3$ times as large as than that of non x-ray irradiated, and is become saturation phenomena after some degree. 2. The conduction current of many times heating x-ray irradiated insulating oil is more than that of a few times heating. 3. The higher temperature x-ray irradiated insulating oil is increased, the more conduction current, and that is increased about ten times as large as when it's temperatures is increased to $80^{\circ}C\;at\;30^{\circ}C$, twenty five times at $100^{\circ}C$. 4. The dependence of electrode materials is appeared at the low electric field, and the small gap length with Fe > Cu > Al. 5. The low electric field than 3000 v/cm is appeared Ohm's law region, and the high is become saturation region at the I-E characteristics. 6. The larger gap length is become, the more conduction current is increased at the same electric field.

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$Ga_{1-x}In_xSe $ 단결정의 Energy Gap의 온도 의존정에 관한 연구 (Temperatature Dependence of the Energy Gap of $Ga_{1-x}In_xSe $ Single Crystals)

  • 김화택;윤창선
    • 대한전자공학회논문지
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    • 제21권2호
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    • pp.36-46
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    • 1984
  • Ga1-xlnxSe 단결정을 X=0.0∼0.1영역과 X=0.8-1.0영역에서 Bridgman방법으로 성장시켰다. 성장된 Ga1-xlnxSe 단결정은 X=0.0∼0.1영역에서는 hexagonal구조, X=0.8∼1.0영역에서는 rhombohedral 구조를 가지고 있었다. CaInSe 단결정은 간접천이형 energy gap을 가지고 있었으며, 15°K에서 250°K로 시편의 온도가 상승할 때 energy gap 은 감소되었고, 온도계수는 (-2.4∼-4.3)×10-4eV/K으로 주어졌다. Ga1-xlnxSe 단결정의, energy gap에 온도 의존성은 Schmid의 electron-phonon 상호작용의 이론으로 설명할 수 있었다.

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Analysis of Gender Pay Gap in Different Sectors of the Economy in Kazakhstan

  • KIREYEVA, Anel A.;SATYBALDIN, Azimkhan A.
    • The Journal of Asian Finance, Economics and Business
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    • 제6권2호
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    • pp.231-238
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    • 2019
  • This study aims is to analyze of existing concepts of gender stereotypes and gender differences in wages, defining of gender pay gap determinants, and to evaluate the level of discrimination against women in Kazakhstan. This paper begins by reviewing trends in gender stereotypes and gender segregation during the past several decades. In this research, authors propose the methodological tools for presenting a standard form of evaluation of gender pay gap. The developed methodological tools will allow providing authentic and formal analysis on gender pay gap and identifying the main determinants of gender pay differences. Further, the obtained results showed the distribution of wage gap in Kazakhstan's regions and the Duncan's dissimilation index allows us to trace the dynamics of changes in the professional structure between men and women. According to the results, gender pay gap is narrowing with the reduction of the job level and discrimination is related to differences in human capital and education. Wages in the industrial sector are higher for men than for women, because men's professions are characterized by severe and unhealthy working conditions. In addition, employers prefer male managers, but if they take woman managers, they give them salary 3 times less.

GaP 단결정의 성장과 특성에 관하여 (On the Growth and Properties of GaP Single Crystals)

  • 김선태;문동찬
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1992년도 춘계학술대회 논문집
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    • pp.50-53
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    • 1992
  • The GaP crystals are growth by Synthesis Solute Diffusion(SSD) method and its properties are investigated. Etch pits density along vertical direction of ingot is increased from 3.8${\times}$10$^4$cm$\^$-2/ of first freeze to 2.3${\times}$10$\^$5/cm$\^$-2/ of last freeze part. The carrier concentration and mobilities are measured to 197.49$\textrm{cm}^2$/V. sec and 6.75${\times}$10$\^$15/cm$\^$-3/ at room temperature. The temperature dependence of optical energy gap is empilically fitted to E$\_$g/(T)=2.3383-(6.082${\times}$10$\^$-4/T${\times}$/(373.096+T)[eV]. Photo-luminescence spectra measured at low temperature are consist with sharp line-spectra near band-gap energy and radiative recombination between shallow Si-donor to Zn-acceptor and its phonon reprica, and broad emission. The infrared absorption in GaP is cause to phonon coupling modes of TO, LO, LA, TA$_1$, TA$_2$and vibration modes of Ga$_2$O, Si-donor and Zn-acceptor, respectively.

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