• 제목/요약/키워드: metastable

검색결과 271건 처리시간 0.029초

Always Metastable State True Random Number Generator

  • Seo, Hwa-Jeong;Kim, Ho-Won
    • Journal of information and communication convergence engineering
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    • 제10권3호
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    • pp.253-257
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    • 2012
  • This paper presents an efficient filtering system for a metastable state-based true random number generator. To output a result with high randomness, we use loop-storage for storing the value of metastability. During the metastable state, the output value is accumulated to the storage. When the non-metastable state arises, the stored metastable value will be used for output instead of the result of the non-metastable state. As a result, we can maintain high entropy together with the original throughput.

아세트아미노펜의 결정다형에 관한 연구 (Study on the Polymorphism of Acetaminophen)

  • 손영택
    • Journal of Pharmaceutical Investigation
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    • 제20권2호
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    • pp.97-103
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    • 1990
  • The metastable modification of acetaminophen was prepared in industry scale. It was found that the dissolution rate of the metastable modification was greater than that of the original powder. The metastable modification was transformed to the stable modification by grinding, but it was not transformed by compression. Starch and lactose inhibited this transformation of the metastable modification to the stable modification by grinding.

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A simple analysis on the abnormal behavior of the argon metastable density in an inductively coupled Ar plasma

  • 박민;유신재;김정형;성대진;신용현;장홍영
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2009년도 제38회 동계학술대회 초록집
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    • pp.438-438
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    • 2010
  • The abnormal behavior of the argon metastable density during the E-H mode transition in argon ICP discharge was investigated. Lots of investigations including global models expected that during and after the mode transition of ICP discharge, the density of metastable increases with applied rf power (i.e. electron density). However, recent direct measurement of metastable density revealed that the metastable density of argon decreases with the applied power during and after the mode transition. This result may not be explained by the previous global model which is based on the assumption of the Maxwellian electron energy distribution function (EEDF). In this paper, to explain this abnormal behavior with simple manners, a simple global model taking account of the effect of the non-Maxwellian EEDFs incorporating into a set of coupled rate equations is proposed. The result showed that the calculated metastable density taking account of non-Maxwellian EEDF and its evolution during the transition has an abnormal behavior with electron density and is in good agreement with the previous measurement results, indicating the close coupling of electron kinetics and the behavior of metastable density. The proposed simple model is expected to provide qualitative kinetic insight to understand the behavior of the metastable density in various plasma discharges which typically exhibit non-Maxwellian distribution.

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Synchronizer의 Metastable 현상 및 그의 개선 방법에 관한 연구 (A Study on the Metastabel Phenomena and its Improvement Method in the Synchronizer)

  • 정연만;이종각
    • 대한전자공학회논문지
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    • 제14권5호
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    • pp.1-6
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    • 1977
  • synchronizer의 입력단에 비동기된 두 신호가 인가되었을 때 일어나는 Metastable 현상에 대한 회로의 해석과 Metastable point에서 stable state로 천이되는 과정에서 일어나는 현상을 해석하였으며, 이러한 mishappen 상태에 의해 기인하는 logic failure를 개선하기 위한 방법으로써, Inverter Method, open collector Method를 사용하여 올바른 논리를 이론과 실험을 통하여 구현하였다.

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Behaviors of excited states argon atom density in ICP discharge

  • 박민;유신재;김정형;성대진;신용현;장홍영
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.203-203
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    • 2011
  • Metastable statates, resonant states in 4s level and excited states in 4p level were investigated with a simple global model and examined by the LIF experiments. Metastable states exhibit an anomalous behavior with the plasma density, on the other hands, other states show monotonous increasing behaviors. It turns out that the metastable state can have such an anomalous behavior due to its special characteristic, electric dipole radiation forbidden. It is expected to resolve the ambiguity of previously reported metastable density behaviors and provide further understanding.

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NEUTRON-INDUCED CAVITATION TENSION METASTABLE PRESSURE THRESHOLDS OF LIQUID MIXTURES

  • Xu, Y.;Webster, J.A.;Lapinskas, J.;Taleyarkhan, R.P.
    • Nuclear Engineering and Technology
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    • 제41권7호
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    • pp.979-988
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    • 2009
  • Tensioned metastable fluids provide a powerful means for low-cost, efficient detection of a wide range of nuclear particles with spectroscopic capabilities. Past work in this field has relied on one-component liquids. Pure liquids may provide very good detection capability in some aspects, such as low thresholds or large radiation interaction cross sections, but it is rare to find a liquid that is a perfect candidate on both counts. It was hypothesized that liquid mixtures could offer optimal benefits and present more options for advancement. However, not much is known about radiation-induced thermal-hydraulics involving destabilization of mixtures of tensioned metastable fluids. This paper presents results of experiments that assess key thermophysical properties of liquid mixtures governing fast neutron radiation-induced cavitation in liquid mixtures. Experiments were conducted by placing liquid mixtures of various proportions in tension metastable states using Purdue's centrifugally-tensioned metastable fluid detector (CTMFD) apparatus. Liquids chosen for this study covered a good representation of both thermal and fast neutron interaction cross sections, a range of cavitation onset thresholds and a range of thermophysical properties. Experiments were devised to measure the effective liquid mixture viscosity and surface tension. Neutron-induced tension metastability thresholds were found to vary non-linearly with mixture concentration; these thresholds varied linearly with surface tension and inversely with mixture vapor pressure (on a semi-log scale), and no visible trend with mixture viscosity nor with latent heat of vaporization.

Synthesis of LaMnO3-Diamond Composites and Their Photocatalytic Activity in the Degradation of Weak Acid Red C-3GN

  • Huang, Hao;Lu, Benqian;Liu, Yuanyuan;Wang, Xeuqian;Hu, Jie
    • Nano
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    • 제13권10호
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    • pp.1850121.1-1850121.11
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    • 2018
  • In this study, a series of $LaMnO_3$-diamond composites with varied $LaMnO_3$ mass contents supported on micro-diamond have been synthesized using a sol-gel method. The as-prepared composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and the Fourier transform infrared spectra (FTIR). Meanwhile, the photocatalytic performances were also tested by photoluminescence (PL) spectroscopy, ultraviolet-visible diffuse reflection spectra (UV-Vis DRS) and the degradation of weak acid red C-3GN (RC-3GN). Results show that the peak position of $LaMnO_3$ is shifted to low angle after the introduction of diamond, and perovskite particles uniformly distributed on the surface of diamond, forming a network structure, which can increase the active sites and the absorption of dye molecules. When the mass ratio of $LaMnO_3$ and diamond is 1:2 (LMO-Dia-2), the composite shows the most excellent photocatalytic activity. This result offers a sample route to enlarge the range of the application of micro-diamond and provide a new carrier for perovskite photocatalysts.

Ti-5Mo-xFe (x=2,4 wt%) 합금의 Fe 첨가에 따른 마모 메커니즘 변화와 내마모 특성 분석 (Analysis of Wear Resistance and Wear Mechanism Change of Ti-5Mo-xFe (x=2,4 wt%) Alloys Based on Fe Addition)

  • 정영훈;이용재;이동근
    • 열처리공학회지
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    • 제37권5호
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    • pp.247-254
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    • 2024
  • Metastable β titanium alloys have been used in implants due to their high specific strength and excellent corrosion resistance. However, the high cost of β-stabilizing elements limits the application of metastable β titanium alloys. Consequently, research has been conducted on low-cost metastable β titanium alloys using relatively inexpenisve β-stabilizing elements such as Mo and Fe. This study analyzes the wear resistance of Ti-5Mo-xFe (x=2,4 wt%) alloys, designed and manufactured as low-cost metastable β titanium alloys. The wear mechanisms of Ti-5Mo-xFe alloys were identified through ball-on disk testing and observation of the worn surfaces. Additionally, the influence of Fe addition on the microstructure and the resulting changes in wear resistance were examined. The wear resistance of the Ti-5Mo-xFe alloys were evaluated in comparison to the Ti-6Al-4V ELI alloy.