• Title/Summary/Keyword: Strain Effect

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Investigation of 1D sand compression response using enhanced compressibility model

  • Chong, Song-Hun
    • Geomechanics and Engineering
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    • v.25 no.4
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    • pp.341-345
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    • 2021
  • 1D sand compression response to ko-loading experiences volume contraction from low to high effective stress regimes. Previous study suggested compressibility model with physically correct asymptotic void ratios at low and high stress levels and examined only for both remolded clays and natural clays. This study extends the validity of Enhanced Terzaghi model for different sand types complied from 1D compression data. The model involved with four parameters can adequately fit 1D sand compression data for a wide stress range. The low stress obtained from fitting parameters helps to identify the initial fabric conditions. In addition, strong correlation between compressibility and the void ratio at low stress facilitates determination of self-consistent fitting parameters. The computed tangent constrained modulus can capture monotonic stiffening effect induced by an increase in effective stress. The magnitude of tangent stiffness during large strain test should not be associated with small strain stiffness values. The use of a single continuous function to capture 1D stress-strain sand response to ko-loading can improve numerical efficiency and systematically quantify the yield stress instead of ad hoc methods.

Biological Control of Plant Pathogens by Bacillus sp. AB02. (Bacillus sp. AB02를 이용한 식물 병원균에 대한 생물검정)

  • Kim, Keun-Ki;Kim, Yong-Chul;Choi, Young-Whan;Sin, Taek-Sun;Park, Ki-Do;Kang, Ui-Gum;Choi, Yong-Lark;Park, Hyean-Cheal
    • Journal of Life Science
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    • v.18 no.6
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    • pp.858-864
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    • 2008
  • In the greenhouse fields for fruits and vegetables during the winter in Korea, there are serious damages by the sclerotium diseases due to the low temperature and humidity. This study was carried out to select an antagonic agent for the biological control of the sclerotium diseases. The 55 antagonic agents were selected from the rhizosphere in soil where the fruits and vegetables were cultivated in the green house fields, and strain AB02 among the tested isolates was estimated to be the strongest antagonist against the sclerotium disease. Using strain AB02, the antifungal spectrum was tested against 5 different plant pathogens. According to the results of the test, strain AB02 . showed the high antagonistic effect against Botrytis cinerea and Sclerotinia sclerotiorum. For the experiment of biological control against the sclerotium disease, it was estimated the suppression effect and the control effect by the strain in the pot experiment using the green perilla. According to the result of the pot experiments, the suppression effect was 40% and the control effect was 62%, respectively. For the stimulation effect of the tested plant growth by strain AB02 compared to the control, it was improved as 120% for the total length, 141% for the liveweight, 121% for the total number of leaves, 185% for the leaf area, and 327% for the liveweight of the root, respectively. Strain AB02 showing the antagonistic effect against the sclerotium disease and the stimulation effect for the plant growth was identified as Bacillus sp.

Conditioned Viscoelastic - Characteristics of Human Aorta

  • Whang, Min-Cheol
    • Proceedings of the KOSOMBE Conference
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    • v.1996 no.05
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    • pp.164-166
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    • 1996
  • Human aorta has viscoelastic behavior. The test of tissues such as aorta, skin, muscle, and ok. is required to consider visco effect on deformation behavior. Creep and slow recovery are main aspects of viscoelasticity of tissue engineering. Volumatric strain plays a important role in determine slow recovery of human arota. This study is to suggest the method avoiding viscous effect in tissue experiment The results shows the time scale when the specimen can be fully recovered from slow deformation. Also, this study observes the qualitative creep-effect on elastic strain in 1 minute at the same loading.

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Micro-scale dependent static stress and strain analyses of thickness-stretching micro plate in sport application

  • Mingjun Xia
    • Advances in concrete construction
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    • v.15 no.5
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    • pp.349-358
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    • 2023
  • Aim of this work is investigating effect of thickness-stretching formulation on the quasi three-dimensional analysis of micro plate based on a thickness-stretched and shear deformable model through principle of virtual work and micro-scale dependent constitutive relations. Governing differential equations are derived in terms of five unknown functions and the analytical solution is derived using Navier's technique. To explore effect of thickness stretching model on the static results, a comparison between the results with and without thickness stretching effect is presented.

The Fate of Strain-Specific Protein in xD Strain of Amoeba proteus (Amoeba proteus xD Strain의 변이주 특이성 단백질의 운영)

  • 안태인
    • The Korean Journal of Zoology
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    • v.26 no.3
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    • pp.181-192
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    • 1983
  • Cytosol protein patterns of two strains of A. proteus, tD and xD strain, were compared by two dimensional gel electrophoresis. Among the 200 major polypeptides that could be stained by silver stain method, tD strain contained a cell specific protein whose molecular weight was 45,000 dalton, pI 5.9. On the other hand, the cytosol and the symbiotic vesicles of xD strain contained a symbiosis specific protein (M.W. 29,000; pI 5.5). The fate of the symbiosis specific protein depended on the presence of symbiotic bacteria in the experiment of high temperature effect and of experimental infection. The significance of these results is discussed in relation to their function in organismic association on the basis of the previous findings.

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Real-Time Observation of Temperature-Dependen Strain in Poly (3-hexylthiophene) Crystals in a Mixed Donor and Acceptor Thin Film

  • Lee, Hyeon-Hwi;Kim, Hyo-Jeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.163-163
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    • 2012
  • We observed strain evolution of P3HT crystals in P3HT:PCBM films and the effect of Al electrode on the evolution during real time annealing process. Based on simple assumptions, both relaxed lattice parameters and thermal expansion coefficient could be quantitatively determined. P3HT:PCBM films displayed tensile strain in as-prepared samples regardless of the presence of an Al layer. In the absence of Al layer, P3HT crystals showed only strain relaxation at an annealing temperature of $180^{\circ}C$. Meanwhile In the presence of an Al layer, the strain was relaxed and changed to compressive strain at around 120C annealing temperature, which indicated a tightening of the thiophene ring packing. These behaviors support the improved performance of devices fabricated by post annealing process.

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Study of Strain/Counterstrain Technique (좌상/역좌상기법에 대한 고찰)

  • Song, Yun-Kyung;Lim, Hyung-Ho;Park, Sung-Ho
    • The Journal of Korea CHUNA Manual Medicine
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    • v.4 no.1
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    • pp.99-109
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    • 2003
  • Dr. Lawrence H Jones developed innovative approach for the treatment of neuromuscular and musculo-skeletal disorders such as fibromyalgia, myofacial pain syndrome, any other muscle pain. This technique is called Strain/Counterstrain technique which uses effect of neuromuscular reflex for treatment of strain. First, Relieving spinal or other joint pain by passively putting the joint into its position of greatest comfort; secondly relieving pain by reduction and arrest of the continuing inappropriate proprioceptor activity. This was accomplished by markedly shortening the muscle that contains the malfunctioning muscle spindle by applying. mild strain to its antagonists. In other words, the inappropriate strain reflex is inhibited by application of counterstrain. Many other techniques have been developed for treating of muscle pain due to somatic dysfunction, but we want to introduce you to strain/counterstrain technique because this is basic concept and theory of Chum therapy for controling motor system.

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Application of the Growth-Strain Method for Shape Optimization (형상 최적화를 위한 성장-변형률법의 적용)

  • 이경래
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.8 no.2
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    • pp.27-34
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    • 1999
  • The growth-strain method was used for shape optimization, which carries out the optimization by distributing uniformly the distributed parameter such as von Mises stress and shear strain energy density. Shape optimization is carried out by iteration of stress analysis and growth strain analysis. In this study, the effect of growth ratio in the method was investigated and then the range of the adequate value of the growth ratio was determined. Also the growth-strain method was improved by applying the linear PID control theory in order to control volume required by a designer. Finally, an automatic shape optimization system was built up by the improved growth-strain method with a commercial software using finite element method. The effectiveness and practicability of the developed shape optimization system was verified by some examples.

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Experimental and Numerical Analysis for Superelastic Behaviors of SMAs with Strain-rate Dependence (변형률 속도에 따른 형상기억합금 초탄성 거동의 실험 및 해석 연구)

  • Roh, Jin-Ho;Park, Jeong-In;Lee, Soo-Yong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.39 no.1
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    • pp.9-15
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    • 2011
  • The influence of the strain-rate on the superelastic behaviors of shape memory alloys (SMAs) wires is experimentally and numerically investigated. The one-dimensional SMA constitutive equations considering strain-rate effect is developed. The evolution of stress-strain curves of SMA wires is examined with various strain-rates. Results show that the superelastic behaviors of SMAs may significantly be changed depending on the variation of strain-rate.

Parental strain, mastery, sex role attitude, and dyadic adjustment after the transition to parenthood in the dual earner family (취업부부의 부모기 전이후 부모로서의 긴장감, 지배감, 성역할태도와 결혼적응)

  • 고선주
    • Journal of the Korean Home Economics Association
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    • v.35 no.5
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    • pp.17-32
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    • 1997
  • The purpose of this study is to explore parental strain, mastery, sex role attitude and dyadic adjustment after the transition to parenthood in dual earner family. Using couple data from a sample of 284 dual earner couple, pair t-test, multiple regression analysis, one was ANOVA was used. Major findings were as follows. 1) There were differences between wives and husbands in dyadic adjustment, physical strain, mastery, sex role attitude. Specially, couples experience more emotional strain than physical strain, and wives experience more parental strain than husbands. 2) Couple's parental strain is considered personal attribution rather than family one, but mastery is different. 3) Couple's psychological variables have an effect on the dyadic adjustment sores, especially husband's sex role attitude influences own dyadic adjustment and wife's dyadic adjustment. Wife's mastery also own dyadic adjustment and husband's dyadic adujstment.

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