• Title/Summary/Keyword: SFIO

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고연소속도 추진제용 연소촉매 연구

  • 황갑성;임유진;김창기
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 1996.11a
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    • pp.193-198
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    • 1996
  • 고연소속도 HTPB/AP 추진제를 얻기 위하여 현재 각광받고 있는 3종의 철화합물 연소촉매를 선정하여 연소속도 증진효과와 기계적 특성, 공정성 및 노화특성에 미치는 영향을 검토하였다. 사용한 철 화합물은 HTPB 프리폴리머에 silicone-ferrocene이 그라프트된 $BUTACENE^$\circledR$$ 과 결합제 역할을 하는 acylaziridinyl ferrocene(AAF), 그리고 입자크기가 30nm인 $NANOCAT^$\circledR$$ superfine iron oxide(SFIO)이었다. 이들 철 화합물을 추진제에 적용한 결과 공정성의 경우 $BUTACENE^$\circledR$$ 은 혼합점도가 높았으나 pot life의 감소는 없었으며 AAF와 SFIO는 혼합점도는 비교적 낮은 반면 pot life가 현저히 감소하는 경향을 보였다. 추진제의 노화거동은 연소촉매를 사용하지 않았을 때보다 저하되었으나 metal deactivating 산화방지제인 $PRO-TECH^$\circledR$$ 과 함께 사용할 경우 공정성 및 노화특성 모두 바람직한 수준으로 향상되었다. 기계적 특성은 SFIO를 제외하고는 저하되었으며 $BUTACENE^$\circledR$$ 은 프리폴리머로서, AAF는 결합제로서의 기능이 다소 미흡하였다. 한편 연소촉매의 함량에 따른 촉매효과는 AAF>SFIO>$BUTACENE^$\circledR$$ 순이었고 철 함량 측면에서는 AAF>$BUTACENE^$\circledR$$ >SFIO 순이었다.

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Fraudulent Financial Reporting Practices: Case Study of Satyam Computer Limited

  • Bhasin, Madan Lal
    • The Journal of Economics, Marketing and Management
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    • v.4 no.3
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    • pp.12-24
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    • 2016
  • Fraudulent financial reporting practices can have significant consequences for organizations and all stakeholders, as well as, for public confidence in the capital and security markets. In fact, comprehensive, accurate and reliable financial reporting is the bedrock upon which our markets are based. Keen to project a rosy picture of the Satyam to investors, employees and analysts, Mr. Raju (CEO and Chairman) fudged the account books so that it appeared to be a far bigger enterprise, with high profits and fast growth rate, than it actually was. The Satyam fraud has shattered the dreams of different categories of investors, shocked the government and regulators alike, and led to questioning of the accounting practices of statutory auditors and corporate governance norms in India. This is an exploratory study based on secondary sources of information. An attempt has been made to provide an explanation for various intriguing questions about Satyam scam. After thorough investigations by the CBI and SEBI, they have unveiled the methodology by which Satyam fraud was engineered. Finally, we recommend "Fraudulent reporting practices should be considered as a serious crime, and accounting bodies, courts and other regulatory authorities in India need to adopt very strict punitive measures to stop such unethical practices."

Temporal characterization of femtosecond laser pulses using spectral phase interferometry for direct electric-field reconstuction (주파수 위상 간섭계를 이용한 펨토초 레이저 펄스의 시간적 특성연구)

  • 강용훈;홍경한;남창희
    • Korean Journal of Optics and Photonics
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    • v.12 no.3
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    • pp.219-224
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    • 2001
  • Spectral phase interferometry for direct electric-field reconstruction (SPIDER) was fabricated and used to characterize pulses from a Ti:sapphire oscillator. In the SPIDER apparatus, two replicas of the input pulse were generated with a time delay of 200 fs and were upconverted by use of sum-frequency generation with a strongly chirped pulse using a 8-cm-long SFIO glass block at a 30-11m-thick type II BBO (p-BaBz04) crystal. The resulting interferogram was recorded with a UV-enhanced CCD array in the spectrometer. The spectral phase was retrieved by SPIDER algorithm in combination with independently measured pulse spectrum and the corresponding temporal intensity profile was reconstructed with a duration of 19 fs. As an independent cross-check of the accuracy of the method, we compared the interferometric autocorrelation (lAC) signal calculated from the SPIDER data with a separately measured lAC. The conventional, but unjustified, method of fitting a sechz pulse to the autocorrelation deceivingly yielded a pulse duration of 15 fs. This systematic underestimation of the pulse duration affirms the need for a complete characterization method. From the consideration in this paper, we concluded that the SPIDER could provide an accurate characterization of femtosecond pulses. ulses.

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