• Title/Summary/Keyword: talbot effect

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Design and Fabrication of Microlens Illuminated Aperture Array for Optical ROM Card System (Optical Card 시스템에서의 마이크로렌즈 조사 광프로브 어레이 설계 및 제작)

  • Kang, Shin-Ill;Kim, Seok-Min;Kim, Hong-Min;Lee, Jee-Seung;Lim, Ji-Seok;Busch, Christopher
    • Transactions of the Society of Information Storage Systems
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    • v.2 no.1
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    • pp.1-6
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    • 2006
  • An optical ROM card system which using an optical probe array generated by Talbot effect was proposed as new robust storage solution. To improve the optical density and to decrease the power consumption of the system, it is very important to make the spot sizes of optical probes smaller as well as to increase the optical efficiency from the light source to optical probes. In this study, a microlens illuminated aperture array for generating high efficiency optical probe away with small beam spot was designed and fabricated using monolithic lithography integration method. The maximum intensity of optical probes of microlens illuminated aperture array increased about 12 times of that of aperture array, and the full width half maximum of the optical probe at Talbot plane generated by microlens illuminated aperture array was $0.77{\mu}m$.

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Loss of coolant accident analysis under restriction of reverse flow

  • Radaideh, Majdi I.;Kozlowski, Tomasz;Farawila, Yousef M.
    • Nuclear Engineering and Technology
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    • v.51 no.6
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    • pp.1532-1539
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    • 2019
  • This paper analyzes a new method for reducing boiling water reactor fuel temperature during a Loss of Coolant Accident (LOCA). The method uses a device called Reverse Flow Restriction Device (RFRD) at the inlet of fuel bundles in the core to prevent coolant loss from the bundle inlet due to the reverse flow after a large break in the recirculation loop. The device allows for flow in the forward direction which occurs during normal operation, while after the break, the RFRD device changes its status to prevent reverse flow. In this paper, a detailed simulation of LOCA has been carried out using the U.S. NRC's TRACE code to investigate the effect of RFRD on the flow rate as well as peak clad temperature of BWR fuel bundles during three different LOCA scenarios: small break LOCA (25% LOCA), large break LOCA (100% LOCA), and double-ended guillotine break (200% LOCA). The results demonstrated that the device could substantially block flow reversal in fuel bundles during LOCA, allowing for coolant to remain in the core during the coolant blowdown phase. The device can retain additional cooling water after activating the emergency systems, which maintains the peak clad temperature at lower levels. Moreover, the RFRD achieved the reflood phase (when the saturation temperature of the clad is restored) earlier than without the RFRD.

Induction of Apoptosis and Transient Increase of Phosphorylated MAPKs by Diallyl Disulfide Treatment in Human Nasopharyngeal Carcinoma CNE2 Cells

  • Zhang, Yi Wei;Wen, Jun;Xiao, Jian Bo;Talbot, Simon G.;Li, Gloria C.;Xu, Ming
    • Archives of Pharmacal Research
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    • v.29 no.12
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    • pp.1125-1131
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    • 2006
  • This study was undertaken to elucidate the effect of diallyl disulfide (DADS), an oil-soluble organosulfur compound found in garlic, in suppressing human nasopharyngeal carcinoma cells. A potent increase (of at least 9-fold) in apoptotic cells has accompanied 1) a decrease in cell viability, 2) a increase of the fraction of S-phase cells by up to 63.8%, and 3) a transient increase of the phospho-p38 and phospho-p42/44 (phosphorylated p38 MAPK and phosphorylated p42/44 MAPK) in a time-and concentration-dependent manner. These results indicate that DADS can induce apoptosis in human nasopharyngeal carcinoma cells via, at least partly, S-phase block of the cell cycle, related to a rise in MAPK phosphorylation.

Self-imaging of a phase line grating and analysis of its visibility (위상형 직선격자의 자체결상과 가시도 분석)

  • 백승선;이상일;조재흥;김영란
    • Korean Journal of Optics and Photonics
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    • v.14 no.6
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    • pp.606-612
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    • 2003
  • The self-imaging effect or lensless imaging effect of a phase line grating is theoretically analyzed by using Fresnel diffraction theory, then experimentally investigated. The self-imaging distance $z_{T,p}$, that is the imaging distance being perfectly copied from the phase distribution of the phase grating to its intensity distribution with the magnification of 1X, can be uniquely defined as the (4n-3) $z_{T,a}$/4(n=positive integers), where rte is the well-known self-imaging distance of an amplitude grating. When the coherent laser beam is illuminated at the phase grating, the self-imaged images were obtained at $z_{T,p}$= $z_{T,a}$/4 and $z_{T,p}$=5 $z_{T,a}$/4 without any optics. On the other side, the phase-reversed self-imaging was obviously observed at $z_{T,p}$ = 3 $z_{T,a}$/4. The visibility of self-imaged images of a phase line grating as a function of the number of slits of the input grating was measured by the FFT(Fast Fourier Transform) results of the self-imaging images. As a result a stationary maximum visibility of V = 0.10 can be obtained from a grating with more than 15 slit pairs.n 15 slit pairs.