• 제목/요약/키워드: Poor stability

검색결과 529건 처리시간 0.025초

Variation in seedling growth inhibition due to Maleic Hydrazide treatment of rice(Oryza sativa) and ragi(Eleusine coracana) genotypes and its relationship with yield and adaptability

  • Das, Swarnalata;Sinha, Susil Kumar;Misra, Rama Chandra
    • Journal of Crop Science and Biotechnology
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    • 제11권3호
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    • pp.215-222
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    • 2008
  • Multilocation trials on 36 rice(Oryza sativa) genotypes of 3 different maturity groups were conducted at four different locations of Orissa for 3 years and 30 ragi(Eleusine coracana) genotypes of 2 different maturity groups were evaluated in three environmental conditions for 3 years. Grain yield data were subjected to stability analysis following linear regression model to estimate adaptability and stability parameters, i.e. b, and $S^2d$ Stability of performance of genotypes was also estimated by two other stability parameters viz., ecovalence W and AMMI stability value ASV. The rice and ragi genotypes of different duration groups showed wide variation in their mean yield, b, $S^2d$, W and ASV parameters. Seeds of the 36 rice and 30 ragi genotypes were treated with 500 and 100 ppm aqueous solution of maleic hydrazide(MH) for 24 hours, respectively to study MH-sensitivity. Sensitivity of genotypes to MH treatment was estimated in terms of seedling growth inhibition index(SGI). The rice and ragi genotypes showed wide differences in their MH-sensitivity in terms of SGI. Relationship of MH-sensitivity of genotypes with their yielding ability, adaptability and stability of performance was tested by contingency $x^2$ test. Low sensitivity of rice and ragi genotypes to MH in terms of SGI appeared to be good indicators of high yielding ability of genotypes. Also, low and high MH-sensitivity of genotypes would be a good indicator of better adaptability to rich and poor environments, respectively, in ragi but not in rice. Low MH-sensitivity of genotypes could be the good indicator of stability of yield performance in rice but not in ragi.

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스퍼터 공정을 이용한 SiZnSnO 산화물 반도체 박막 트랜지스터의 증착 온도에 따른 특성 (Effect of Deposition Temperature on the Electrical Performance of SiZnSnO Thin Film Transistors Fabricated by RF Magnetron Sputtering)

  • 고경민;이상렬
    • 한국전기전자재료학회논문지
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    • 제27권5호
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    • pp.282-285
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    • 2014
  • We have investigated the structural and electrical properties of Si-Zn-Sn-O (SZTO) thin films deposited by RF magnetron sputtering at various deposition temperatures from RT to $350^{\circ}C$. All the SZTO thin fims are amorphous structure. The mobility of SZTO thin film has been changed depending on the deposition temperature. SZTO thin film transistor shows mobility of 8.715 $cm^2/Vs$ at room temperature. We performed the electrical stress test by applying gate and drain voltage. SZTO thin film transistor shows good stability deposited at room temperature while showing poor stability deposited at $350^{\circ}C$. As a result, the electrical performance and stability have been changed depending on deposition temperature mainly because high deposition temperature loosened the amorphous structure generating more oxygen vacancies.

$ZnO-Pr_{6}O_{11}$계 바리스터 세라믹스의 직류가속열화 특성 (DC Accelerated Aging Characteristics of $ZnO-Pr_{6}O_{11}$ Based Varistor Ceramics)

  • 김향숙;남춘우
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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    • pp.330-333
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    • 2002
  • The stability against DC accelerated aging stress of $Dy_{2}O_{3}-doped$ $ZnO-Pr_{6}O_{11}-based$ varistor ceramics was investigated. The calculated nonlinear exponent$(\alpha)$ in varistor ceramics without $Dy_{2}O_{3}$ was only 4.9, whereas the $\alpha$ value of the varistors with $Dy_{2}O_{3}$ was abruptly increased in the range of 48.8 to 58.6. The varistor ceramics with $Dy_{2}O_{3}$ content of 1.0 mol% exhibited maximum ${\alpha}$, reaching 58.6, whereas they exhibited very poor stability. While, The varistor ceramics doped with 0.5 mol% $Dy_{2}O_{3}$ exhibited not only the high nonlinearity, which the ${\alpha}$ is 55.3 and the leakage current is $0.1{\mu}A$, but also the highest stability, which the variation rates of varistor voltage and nonlinear exponent are -0.8% and -14.3%, respectively, under DC accelerated aging stress, $0.95 V_{1mA}/150^{\circ}C/24h$.

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Effects of load height application and pre-buckling deflections on lateral buckling of thin-walled beams

  • Mohri, F.;Potier-Ferry, M.
    • Steel and Composite Structures
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    • 제6권5호
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    • pp.401-415
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    • 2006
  • Based on a non-linear model taking into account flexural-torsional couplings, analytical solutions are derived for lateral buckling of simply supported I beams under some representative load cases. A closed form is established for lateral buckling moments. It accounts for bending distribution, load height application and pre-buckling deflections. Coefficients $C_1$ and $C_2$ affected to these parameters are then derived. Regard to well known linear stability solutions, these coefficients are not constant but depend on another coefficient $k_1$ that represents the pre-buckling deflection effects. In numerical simulations, shell elements are used in mesh process. The buckling loads are achieved from solutions of eigenvalue problem and by bifurcations observed on non linear equilibrium paths. It is proved that both the buckling loads derived from linear stability and eigenvalue problem lead to poor results, especially for I sections with large flanges for which the behaviour is predominated by pre-buckling deflection and the coefficient $k_1$ is large. The proposed solutions are in good agreement with numerical bifurcations observed on non linear equilibrium paths.

EPDM/POSS(Polyhedral oligomeric silsesquioxane) 복합재료의 물성 연구 (A Study on Physical Properties of EPDM/Polyhedral Oligomeric Silsesquioxane (POSS) Composites)

  • 박현호
    • 공업화학
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    • 제32권4호
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    • pp.472-477
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    • 2021
  • 다면체 올리고머 실세스퀴옥산 (POSS) 중 케이지 형태 8개의 아크릴레이트 그룹을 포함하는 POSS가 에틸렌-프로필렌-디엔고무 (EPDM) 과산화물 가교에서의 가교 거동, 기계적 특성에 미치는 영향 및 열 안정성 등을 조사하였다. 고무 100 phr당 0~12 phr의 POSS를 함량 별로 혼합하고 과산화물 가교제를 첨가하여 EPDM/POSS 복합재료를 만들었다. 가교 특성 결과 POSS의 아크릴레이트 그룹이 과산화물에 의해 활성화 되었고, 과산화물 가교 효율을 향상시키는 것으로 나타났다. EPDM/POSS 복합재료에서 POSS의 분산안정성은 떨어졌지만, 복합재료의 파단 강도, 신장률 및 열 안정성은 향상되었다.

산성 전해질 기반의 전기 이중층 커패시터용 흑연 집전체의 전기화학적 안정성 평가 (Evaluation of Electrochemical Stability of Graphite Current Collector for Electric Double Layer Capacitor Based on Acid Electrolyte)

  • 박시진;안건형
    • 한국재료학회지
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    • 제31권5호
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    • pp.272-277
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    • 2021
  • Owing to its low cost, easy fabrication process, and good ionic properties, aqueous supercapacitors are under strong consideration as next-generation energy storage devices. However, the limitation of the current collector is its poor electrochemical stability, leading to low energy storage performance. Therefore, a reasonable design of the current collector and the acidic electrolyte is a necessary, as well as interfacial engineering to enhance the electrochemical performance. In the present study, graphite foil, with excellent electrochemical stability and good electrical properties, is suggested as a current collector of aqueous supercapacitors. This strategy results in excellent electrochemical performance, including a high specific capacitance of 215 F g-1 at a current density of 0.1 A g-1, a superior high-rate performance (104 F g-1 at a current density of 20.0 A g-1), and a remarkable cycling stability of 98 % at a current density of 10.0 A g-1 after 9,000 cycles. The superior energy storage performance is mainly ascribed to the improved ionic diffusion ability during cycling.

메밀 추출물의 이상 침전 개선 효과에 관한 연구 (Study on Prevention Method of Abnormal Precipitation in Buckwheat Extracts)

  • 윤성준;조남지;나석환;김영호;김영모
    • 동아시아식생활학회지
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    • 제16권6호
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    • pp.702-706
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    • 2006
  • The aim of this study was to identify the onuses of abnormal precipitation in buckwheat extracts and to suggest the preventive solutions. Abnormal precipitation was formed by the coagulations of small round droplets, and increased when poor quality or old buckwheat used. It was found that, unlike poor quality buckwheat, extracts made from fresh buckwheat showed almost no saccharifying enzyme activity and a lower number of microorganisms. The addition of branched starch to the extracts restricted the occurrence of abnormal precipitation and microorganisms and imparted stability to the extracts.

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록볼트의 2차원 수치해석에 대한 타당성 검토 (A Study on the Validity of 2-Dimensional Analysis of Rock Bolt)

  • 정현석;김보현;양형식
    • 터널과지하공간
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    • 제14권6호
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    • pp.423-428
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    • 2004
  • 편의상 터널을 평면변형률조건으로 해석하는 경우가 많은데 이때 록볼트는 등가의 연속체로 가정하여 해석한다. 본 연구에서는 3차원해석과2차원 해석을 비교하여 현행의 2차원 해석이 타당한지를 평가하였다. 해석결과 불량한 지반에 대한 2차원 해석에서는 $10\%$ 이상의 변형 오차가 발생하여 3차원적 고려가 필요한 것으로 판단되었다.

Transport Properties of Crosslinked Poly Vinyl Alcohol Membrane in Pervaporation

  • Lee, Chul-Haeng;Hong, Won-Hi
    • 한국막학회:학술대회논문집
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    • 한국막학회 1996년도 추계 총회 및 학술발표회
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    • pp.92-93
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    • 1996
  • PVA membrane was widely used in the dehydration pervaporation process. PVA membrane showed remakable selectivity towed water and an excellent film-forming polymer, with a good resistance to orgamic solvents but it has poor stability in aqueous mixtures. Generally the PVA is manufactured by the hydrolysis reaction from poly vinyl acetate(PVAc) and so the degree of PVA hydrolysis is a major parameter for properties of PVA membrane such as the crystallinity and polarity.

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선천성 횡격막탈장 :수술 치험2례 (Congenital postrolateral diaphragmatic hernia; a report of two cases)

  • 전찬규
    • Journal of Chest Surgery
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    • 제28권6호
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    • pp.640-643
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    • 1995
  • Bochdalek hernia is the congenital posterolateral defect in the diaphragm caused by a failure of the pleuroperitoneal canal to close at 8 weeks, gestation. Infants with hernia diagnosed at birth have poor prognosis. Survival rate depends on pulmonary growth and development, preoperative stability and postoperative care. We experienced two cases of Bochdalek hernia, one in right was repaired with patch closure using sheet and the other in left was repaired with simple closure.

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