• 제목/요약/키워드: high $I_c$

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내화처리(耐火處理) 미송(美松) 및 미삼재(美杉材)의 연소후(燃燒後) 잔유(殘留)휨강도(强度)에 관한 연구(硏究) (Studies on the Residual Bending Strength of burned Douglas-fir and Western Hemlock soaked with Fire Retardant Chemicals)

  • 이필우;박헌
    • Journal of the Korean Wood Science and Technology
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    • 제12권3호
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    • pp.15-24
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    • 1984
  • The $3{\times}3{\times}30\;cm^3$ sized specimens of Douglas-fir(Pseudotsuga menziesii) and western hemlock(Tsuga heterophylla) in this study were soaked in four fire-retardant solutions of ammonium sulfate, monoammonium phosphate, diammonium phosphate, and aluminium chloride for 1, 24, 72, 168, and 336 hours. Subsequently they were air-dried and burned at high temperature of ca. $1,800^{\circ}C$ and for short time of 5 minutes. This study estimated the relationship between the adsorbed chemicals and the residual weight ratio or residual bending strength of these partly burned lumbers. The results were as follows; 1) In average amount of chemical adsorption, diammonium phosphate showed the largest and aluminium chloride the smallest regardless of species but monoammonium phosphate was larger in Douglas-fir than that of western hemlock. 2) The amount of chemical adsorption was larger in western hemlock than Douglas-fir on the whole. 3) The amount of chemical adsorption was increased with the increase of soaking time but the rate of increase began to decrease at 200hrs. 4) Residual weight ratios showed no difference between species but showed differences among the chemicals treated i.e. monoammonium phosphate, diammonium phosphate, ammonium sulfate and aluminium chloride in turn from the largest to the smallest. 5) MOR values showed linear increase with the increase of residual weight ratios but showed no difference in species and chemicals respectively. 6) In the relationship between amount of chemical adsorption and MOR, only diammonium phosphate showed the curve of secondary degree with significance in Douglas-fir. 7) The MOE value of burned Douglas-fir lumber increased and showed significance of 99% as the adsorbed chemical amount increased, but among the chemicals only monoammonium phosphate showed significance. The MOE value of burned western hemlock lumber didn't show significance. 8) In only Douglas-fir, the correlation between adsorbed chemical amount and work to proportional limit showed significance in only monoammonium phosphate. And in both Douglas-fir and western hemlock, the correlation between adsorbed chemicals and work to maximum load showed significance in monoammonium phosphate.

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안전필수(Safety-Critical) 시스템의 실시간 운영체제에 대한 안전성 평가 (Safety Evaluation on Real Time Operating Systems for Safety-Critical Systems)

  • 강영두;정길도
    • 한국산학기술학회논문지
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    • 제11권10호
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    • pp.3885-3892
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    • 2010
  • 원자력발전소의 발전소보호계통과 같은 안전필수 시스템은 예상 가능한 사고로부터 인간과 자연을 보호하기 위한 중요 기능을 수행하는 시스템으로써, 어떠한 조건 하에서도 고유의 안전기능을 안정적으로 수행할 수 있도록 설계되어야 한다. 원자력발전소의 안전필수 기능을 수행하는 계측제어시스템에 적용되는 최신의 컴퓨터에는 다양한 하부기기를 감시 및 제어하고, 응용 프로그램을 실행시키기 위한 실시간 운영체제가 탑재되어 있으며, 이러한 실시간 운영체제는 가장 엄격한 소프트웨어 품질이 요구된다. 또한, 예상 가능한 조건에서도 안전필수 시스템의 기능이 적절히 수행될 수 있도록 설계, 분석 및 평가되어야 한다. 그러나 지금까지 국내 원자력발전소 안전필수 시스템에는, 원자력 기준과 품질등급에 따라 개발된 제품이 아닌 상용제품의 실시간 운영체제를 정성적 측면에서 승인(Commercial Grade Item Dedication)하는 방식으로 적용되어 왔다. 이로 인해 실시간 운영체제가 안전필수 기능을 수행하는 데 적합한지를 평가하는 상세 방법론과 경험이 매우 부족한 것으로 파악되고 있다. 특히, 안전필수 시스템에 적용함을 목적으로 신규 개발되는 실시간 운영체제의 경우, 안전성을 평가하기 위한 적절한 방법을 도출하기에 어려움이 있는 것으로 파악되고 있다. 본 논문에서는 원전의 안전필수 기능을 수행하는 실시간 운영체제의 설계요구사항을 기반으로, 안전필수 실시간 운영체제에 대한 안전성 분석 및 평가 사례를 제시하고자 한다. 본 논문에서 제시한 상세 안전성 평가의 방법과 사례는 향후 타 산업분야에서의 안전필수 실시간 운영체제 개발 및 안전성 평가에 활용될 수 있을 것으로 기대된다.

이축 배향화된 전도성 복합산화물의 금속 기판의 제조와 분석 (Fabrication and Characterization of Bi-axial Textured Conductive Perovskite-type Oxide Deposited on Metal Substrates for Coated Conductor.)

  • Sooyeon Han;Jongin Hong;Youngah Jeon;Huyong Tian;Kim, Yangsoo;Kwangsoo No
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
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    • pp.235-235
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    • 2003
  • The development of a buffer layer is an important issue for the second -generation wire, YBCO coated metal wire. The buffer layer demands not only on the prohibition of the reaction between YBCO and metal substrate, but also the proper lattice match and conductivity for high critical current density (Jc) of YBCO superconductor, In order to satisfy these demands, we suggested CaRuO3 as a useful candidate having that the lattice mismatches with Ni (200) and with YBCO are 8.2% and 8.0%, respectively. The CaRuO3 thin films were deposited on Ni substrates using various methods, such as e-beam evaporation and DC and RF magnetron sputtering. These films were investigated using SEM, XRD, pole-figure and AES. In e-beam evaporation, the deposition temperature of CaRuO3 was the most important since both hi-axial texturing and NiO formation between Ni and CaRuO3 depended on it. Also, the oxygen flow rate had i[n effect on the growth of CaRuO3 on Ni substrates. The optimal conditions of crystal growth and film uniformity were 400$^{\circ}C$, 50 ㎃ and 7 ㎸ when oxygen flow rate was 70∼100sccm In RF magnetron sputtering, CaRuO3 was deposited on Ni substrates with various conditions and annealing temperatures. As a result, the conductivity of CaRuO3 thin films was dependent on CaRuO3 layer thickness and fabrication temperature. We suggested the multi-step deposition, such as two-step deposition with different temperature, to prohibit the NiO formation and to control the hi-axial texture.

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액정 디스플레이 배향막을 위한 이온빔 표면조사에 관한 연구 (Ion beam irradiation for surface modification of alignment layers in liquid crystal displays)

  • 오병윤;김병용;이강민;김영환;한정민;이상극;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 춘계학술대회 및 기술 세미나 논문집 디스플레이 광소자
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    • pp.41-41
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    • 2008
  • In general, polyimides (PIs) are used in alignment layers in liquid crystal displays (LCDs). The rubbing alignment technique has been widely used to align the LC molecules on the PI layer. Although this method is suitable for mass production of LCDs because of its simple process and high productivity, it has certain limitations. A rubbed PI surface includes debris left by the cloth, and the generation of electrostatic charges during the rubbing induces local defects, streaks, and a grating-like wavy surface due to nonuniform microgrooves that degrade the display resolution of computer displays and digital television. Additional washing and drying to remove the debris, and overwriting for multi-domain formation to improve the electro-optical characteristics such as the wide viewing angle, reduce the cost-effectiveness of the process. Therefore, an alternative to non-rubbing techniques without changing the LC alignment layer (i.e, PI) is proposed. The surface of LC alignment layers as a function of the ion beam (IE) energy was modified. Various pretilt angles were created on the IB-irradiated PI surfaces. After IB irradiation, the Ar ions did not change the morphology of the PI surface, indicating that the pretilt angle was not due to microgrooves. To verify the compositional behavior for the LC alignment, the chemical bonding states of the ill-irradiated PI surfaces were analyzed in detail by XPS. The chemical structure analysis showed that ability of LCs to align was due to the preferential orientation of the carbon network, which was caused by the breaking of C=O double bonds in the imide ring, parallel to the incident 18 direction. The potential of non-rubbing technology for fabricating display devices was further conformed by achieving the superior electro-optical characteristics, compared to rubbed PI.

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유건종(類腱腫)의 임상적 고찰 (Clinical Investigation of Desmoid Tumors)

  • 이승구;김정만;김형민;강용구;김용식;권순용;이경태;김인
    • 대한골관절종양학회지
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    • 제1권2호
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    • pp.205-209
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    • 1995
  • A desmoid tumor is a locally aggressive growth of connective tissue origin which infiltrates the surrounding tissue and has a marked tendency for recurrence. And so it was also called as an aggressive fibromatosis, musculofascial fibromatosis or fibrosarcoma etc. Thirteen cases of desmoid tumor was treated since 1980, and their retrospective study was done with 79 months of follow-up after initial surgical excision. The female was involved in 12 cases(one male) with the age ranged from 7-50 years, average 28 years, and seven patients in third decade. A slowly growing mass was excised on average 4 months after first notice of the mass, but their margins are not demarcated clearly in most cases. Wide excision in 12 cases was done, but wide excision and saphenous vein graft was performed in one case because of invasion of posterior tibial artery by tumor mass. The tumor was found on extraabdominal region in 8 cases(61.5%) but 5 cases in abdominal wall(38.5%). The recurrence rate was high(6/13, 46.2%), and 11 times in 6 patients were recurred(average 1.8 times), within 27 months of initial excision. Six cases of recurrence were treated with wide excision again in 3 cases, wide excision combined with radiotherapy(4,000-6,000cGy) in 4 cases and wide excision with chemotherapy in one case. During the follow-up for average 21 months after treatment, no recurrences are found. Tumor remission periods without recurrence are average 67 months in all, and 11 years in longest case. Histologically it was very mimic with fibrosarcoma but could be differentiated with Trichrome stain, and their findings are not changed after recurrence.

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안장형 인공 고관절 전치환술 (Saddle Prosthesis)

  • 박일형;인주철;이종민
    • 대한골관절종양학회지
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    • 제1권2호
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    • pp.133-144
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    • 1995
  • 고관절 제거후 재건을 위한 방법으로서의 안장형 인공 고관절 치환술은 동종골 이식술후 고관절 전치환술, 열처리한 자가골 재삽입 후 고관절 전치환술, 좌골 대퇴골간 유합술, 가동 관절로 그대로 두는 방법 등에 비해서 수술 시간의 단축에 의한 감염율 및 기타 이환율의 감소, 술후 조기 보행 가능, 좌식 생활을 하는 한국인의 생활에 편리한 이점이 있다. 이 방법은 Modular system으로 다리 정렬 상태를 잘 보존시킬 수 있으며 필요하다면 추후 골 재건술도 할 수 있는 장점이 있다. 저자들은 비구를 침범한 악성 골 종양을 제거 고관절의 재건을 위해 3예에서 안장형 인공 고관절 치환술을 시행하였다. 이중 1예에서 가역성 서혜부 탈장이 관찰되었으나 12개월, 19개월(사망), 27개월의 추시 관찰 결과 자가 보행, 계단 오르내리기가 가능하고, 쪼그려 앉기와 방바닥에 앉을 수 있으며, 통증없이 일상적인 생활을 할 수 있었다. 따라서, 비구를 침범한 골 종양 제거후의 고관절 재건술의 좋은 방법으로 판단되어 이에 문헌 고찰과 함께 보고하는 바이다.

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생물학적(生物學的) 질소고정(窒素固定)에 관(關)한 연구(硏究) -제(第)1보(報) 야생두과식물근류(野生豆科植物根瘤) 질소고정(窒素固定)에 관(關)한 연구(硏究) (STUDIES ON BIOLOGIAL NITROGEN FIXATION -I. Study on symbiotic nitrogen-fixing activities of wild nodule bacteria)

  • 이상규;류진창
    • 한국토양비료학회지
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    • 제11권1호
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    • pp.1-7
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    • 1978
  • 우리나라 산야(山野)에 분포(分布)되어 있는 수종야생두과식물(數種野生豆科埴物)의 질소고정력(窒素固定力)과 건물생산력(乾物生産力)을 알기 위하여 실내(室內) 및 시험(試驗)한 결과(結果)는 다음과 같다. 1. 야생두과식물(野生豆科埴物)에서 분리(分離)된 균(菌)의 Acetylene 환원력(還元力)(질소고정력(室素固定力))을 조사(調査)한 결과(結果) Rhinchosia Volubilis Lovr.(여우콩)의 근류균(根瘤菌)은 924 n mole, Desmodium Oldhami Oliver(큰도둑놈의 갈쿠리)의 근류균(根瘤菌)은 844 n mole 그리고 Glycine zoja S.et z.의 근류균(根瘤菌)은 271 n mole/test tube/hr로 대두근류균(大豆根瘤菌)의 Rhizobium japonicum 0.6 n mole/test tube/hr 비(比)하여 대단히 높았다. 2. 분리(分離)된 균(菌)의 혈청반응계(血淸反應結果) 공시(供試)된 8종(種)의 균주(菌株) 모두가 Rhizobium japonicum과 상이(相異)한 반응(反應)을 보였다. 3. Glycine soja S.at Z.를 공시(供試)하여 Pot 시험(試驗)한 결과(結果) 4. 각시기별(各時期別) 총균류수(總根瘤數)는 NoPK구(區)보다 종합처리구(綜合處理區)에서 현저(顯著)히 많았으나 유효근류(有效根瘤)의 수(數)의 차(差)는 크지 않았다. 5. 식물체내(植物體內) 질소함량(窒素含量)의 증가(增加)는 건물(乾物)의 증가(增加)를 갖여왔다. 다. 근류개체당(根瘤個體當) 질소고정량(窒素固定量)은 종합처리구(綜合處理區)보다 NoPK구(區)에서 높았다.

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Deposition of Mucin Coat on Rabbit Embryos Cultured In Vitro Following Oviductal Transfer

  • Joung S. Y;Yang J. H;Im K S;Lee S. H;Park C. S;Jin D. I
    • Reproductive and Developmental Biology
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    • 제28권3호
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    • pp.141-145
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    • 2004
  • Mucin coat is deposited on the embryos during passage through the oviduct in rabbit. When in vitro cultured blastocysts were transferred to the recipients, the lack of mucin coat might account in part for failure of pregnancy after transfer. The present study were carried out to investigate whether deposition of mucin coat were induced when in vitro cultured blastocysts were transferred to recipients. At 19 ~20 hours post-coitus one-cell embryos were collected by flushing oviducts. These embryos cultured for 72 hours were reached to blastocyst stage. And these blastocysts were transferred to the oviduct of asynchronized (one day later than the donors) and synchronized recipient. To confirm deposition of the mucin coat, blastocysts transferred to the oviduct were recovered at 24 and 48 hours after the transfer. Fifty eight percent of blastocysts recovered from uterus of asynchronous recipient at 24 hours after transfer and 92.9% of blastocysts recovered from uterus of synchronous recipient were 0~10 ㎛ of mucin coat thickness. And 11.8% of blastocysts of asynchronized recipients and 7.1% of blastocysts from asynchronized recipients were in 11~20 ㎛ of mucin coat thickness. When blastocysts were recovered from uterus at 48 hours after transfer, 87.0% of blastocysts from asynchronized recipients and 5.9% of blastocyst from synchronized recipients were in 0~10 ㎛ of mucin coat thickness. And 76.5% of blastocysts of synchronized recipients and 4.4% of blastocysts from asynchronized recipients were in 11~20 ㎛ of mucin coat thickness. From these results it is speculated that the low implantation rate of in vitro cultured rabbit blastocysts transferred to oviduct of recipient was caused by high degeneration of the embryo after transfer and inappropriate deposition of mucin coat.

한우 도축시 혈청 호르몬과 혈액 성분의 상관 관계 분석 (Correlation Analysis of Serum Hormones and Components in Hanwoo during Slaughtering Process)

  • 전기준;김명직;조규호;유재원;김인철;최재관;정호영;이학교
    • 한국수정란이식학회지
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    • 제21권4호
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    • pp.287-297
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    • 2006
  • 한우에서 도축 전 혈청 호르몬 및 혈액 성분의 농도 변화가 거세우와 비거세우에서 공통적으로 나타난 현상은 도축 2개월 전에서 수송 직전 사이에 cortisol과 creatinine이 증가하였고 calcium은 감소하였다. 수송 직전에 비해 수송 직후에는 IGF-1 농도가 감소하였으나 수송 직전에 비해 도축 시에는 IP농도가 감소했다. 혈청 호르몬 및 대사 물질들에서 도축 2개월 전, 수송 직전, 수송 직후 및 도축시 혈청들 간의 상관 관계는 도축 2개월 전 농도와 수송 직전 농도간에 정의 상관 관계를 보인 혈청은 거세우에서는 IGF-1, TP, albumin, creatinine, HDLC 및 globulin이며 비거세우에서는 creatinine과 globulin이었고, 도축 2개월 전 혈청과 도축시 혈청 간에 정의 상관관계를 보인 혈청 성분은 거세우에서는 IGF-1, BUN, IP 및 HDLC이었고, 비거세우에서는 creatinine이었다. 그리고 수송 직전 혈청과 도축시 혈청 간에 정의 상관 관계가 있는 혈청 성분은 거세우에서는 testosterone, IGF-1, creatinine, triglyceride, HDLC 및 globulin이었고, 비거세우에서는 TP, creatinine, HDLC 및 globulin으로 나타났다.

식품중 불법함유된 발기부전치료제 성분 검출을 위한 동시분석법 연구 (Simultaneous Identification/Determination System for Sildenafil, Homosildenafil, Vardenafil and Tadalafil as Adulterants in Foods)

  • 장재희;박건상;박혜경;구용의;최윤주;황인경;김대병
    • 한국식품위생안전성학회지
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    • 제18권4호
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    • pp.195-201
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    • 2003
  • 본 연구에서는 국내 ${\cdot}$ 외에서 유통되는 건강관련식품 중 성기능 개선 및 효과에 대하여 광고 ${\cdot}$ 판매하고 있는 제품들에 대하여 최근 의약품으로 허가된 발기부전치료제인 sildenafil, vardenafil, tadalafil 및 sildenafil의 유사물질인 homosildenafil을 대상으로 정성과 정량을 위한 동시분석법을 개발하고 유통 제품 중의 함량을 분석하여 함유 실태를 파악하고자 하였다. 네 가지 성분을 확인할 수 있는 TLS와 LC/MS 분석방법을 개발하였으며, LC/PDA를 사용한 동시 정량분석법을 개발하고, 건강보조식품 등 건강관련 식품중 sildenafil 등 4종 물질에 대해 총 35개의 시료를 분석한 결과 sildenafil이 7종에서 0.4 mg/g~360.9 mg/g, homosildenafil이 7종에서 2.2 mg/g~336.0 mg/g, tadalafid이 2종에서 각각 19.2mg/g, 429.3mg/g로 검출되었으며, 본 여구에서 개발한 동시분석법을 유통식품에 적용 가능하였다.