• Title/Summary/Keyword: Poor stability

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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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    • v.11 no.3
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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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Effect of Deposition Temperature on the Electrical Performance of SiZnSnO Thin Film Transistors Fabricated by RF Magnetron Sputtering (스퍼터 공정을 이용한 SiZnSnO 산화물 반도체 박막 트랜지스터의 증착 온도에 따른 특성)

  • Ko, Kyung Min;Lee, Sang Yeol
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.27 no.5
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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.

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

  • Kim, Hyang-Suk;Nahm, Choon-Woo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.11a
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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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    • v.6 no.5
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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.

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

  • Park, Hyun-Ho
    • Applied Chemistry for Engineering
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    • v.32 no.4
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    • pp.472-477
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    • 2021
  • The crosslinking behavior of polyhedral oligomeric silsesquioxane (POSS) containing eight acrylate groups in a cage form in ethylene-propylene-diene rubber (EPDM) peroxide crosslinking, the effect on mechanical properties, and the thermal stability were investigated. An EPDM/POSS composite material was prepared by mixing 0 to 12 parts per hundreds of rubber (phr) of POSS per 100 phr of rubber by content and adding a peroxide crosslinking agent. As a result of crosslinking properties, it was found that the acrylate group of POSS was activated by peroxide and improved the peroxide crosslinking efficiency. Although the dispersion stability of POSS in EPDM/POSS composites was poor, the fracture strength, elongation and thermal stability were improved.

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

  • Park, Sijin;An, Geon-Hyoung
    • Korean Journal of Materials Research
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    • v.31 no.5
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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.

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

  • Yoon, Seong-Jun;Cho, Nam-Ji;Na, Seog-Hwan;Kim, Young-Ho;Kim, Young-Mo
    • Journal of the East Asian Society of Dietary Life
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    • v.16 no.6
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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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A Study on the Validity of 2-Dimensional Analysis of Rock Bolt (록볼트의 2차원 수치해석에 대한 타당성 검토)

  • Seok Jeong Hyeon;Kim Bo Byun;Sik Yang Hyung
    • Tunnel and Underground Space
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    • v.14 no.6 s.53
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    • pp.423-428
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    • 2004
  • The stability of tunnels is usually analyzed as plain strain condition and rock bolts are assumed as 2 dimensional equivalent continuum structures. In this study, 2 and 3 dimensional numerical analyses were conducted to verify the validity of 2 dimensional analysis of rock bolts. Since the results of 2 dimensional analysis showed more than $10\%$ differences in poor rocks, it seems that 3 dimensional analysis is required in poor rocks.

Transport Properties of Crosslinked Poly Vinyl Alcohol Membrane in Pervaporation

  • Lee, Chul-Haeng;Hong, Won-Hi
    • Proceedings of the Membrane Society of Korea Conference
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    • 1996.10a
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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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Congenital postrolateral diaphragmatic hernia; a report of two cases (선천성 횡격막탈장 :수술 치험2례)

  • 전찬규
    • Journal of Chest Surgery
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    • v.28 no.6
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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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