• Title/Summary/Keyword: Excess

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Effects of AlN Ratio on Microstructure of AlN Films Grown by PAMBE (PAMBE를 이용하여 성장된 AlN 박막의 미세구조에 미치는 Al/N 비율 영향)

  • 홍성의;한기평;백문철;조경익;윤순길
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.12
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    • pp.972-978
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    • 2001
  • Some effects of Al/N ratio on microstructure of AlN films grown on Si(111) substrates by PAMBE were investigated. Al/N ratio was controlled by rf power of N$_2$ plasma source system. Al excess or N excess conditions were obtained below or above 350 W rf power, respectively. Surface roughness and morphology of AlN film grown at Al/N=1.0 showed the best result. Under Al excess condition, it was suggested that excess Al atoms which did not contribute to the growth of AlN film prevent the normal crystal growth and make abnormal growth of some columns. However, under N excess condition, it was explained that some of the excess active N source turned into gas state and then desorbed out from substrate.

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Analysis of Stress Singularity for the Excess Adhesive of Interface in Adhesively Bonded Joint (접착이음의 계면덧살에 대한 응력특이성 해석)

  • Chung, Nam-Yong;Park, Cheol-Hee
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.3
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    • pp.439-445
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    • 2012
  • The stress singularity for the excess adhesive on interface of adhesively bonded joint was investigated by using the 2-dimensional elastic boundary element method (BEM). To establish a reasonable strength evaluation method and a fracture criterion for the excess adhesive of interface in adhesively bonded joint, it is necessary to evaluate fracture parameters with various bonding conditions. Under the variations of adhesively bonded thickness (h) and diameter (d) for the excess adhesive, a stress analysis was performed, and from the results, the stress singularity index (${\lambda}$) and the stress singularity factor (${\Gamma}$) were calculated. The variations have a great influences on the stress singularity for the excess adhesive of interface in adhesively bonded joint, and the ${\Gamma}$ is reduced as the "h" and "d" increase.

A Study on Change of Excess Volume in Membrane of Holobacterium Holobium (Halobacterium Halobium의 Membrane에서 잉여부피 변화에 관한 연구)

  • Kim, Ki-Jun;Lee, Joo-Youb
    • Journal of the Korean Applied Science and Technology
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    • v.28 no.2
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    • pp.247-250
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    • 2011
  • The excess volumes of mixing of benzyl alcohol and halothane in vesicle and in suspensions of several lipids have been determined at $25^{\circ}C$ it using a excess volume dilatometer. The potency of general anesthetics has long been known to correlate with lipid solubility. Denaturations of the vesicle, which is a sole membrane protein in the purple membrane of Halobacteriun Halobium, were studied by absorption changes at 280 nm and fluorescence changes at 330 nm and excess volume dilatometer. The particle size analysis of viscous polymer solutions by diffusional interchange is the key step by measurement. The excess volume of mixing in chitosan was found to be negative, whereas them of purple membrane, Halobacteriun Halobium and red membrane were positive in benzyl alcohol and halothane. This result was confirmed as Miller's supposition.

Measurement of blood base-excess concentration in cows with abomasal torsion and right-side displacement of the abomasum (제4위 우측전위증과 제4위 염전을 지닌 젖소에서 혈중 염기초과 농도의 측정)

  • Jeong, Soon-wuk
    • Korean Journal of Veterinary Research
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    • v.35 no.3
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    • pp.631-633
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    • 1995
  • 70 cows with abomasal torsion and 71 cows with right-side displacement of the abomasum were examined to determine whether the preoperative blood base-excess concentration could be used both as a prognostic indicator for postoperative recovery in cows with abomasal torsion and as an aid in differentiating between abomasal torsion and right-side displacement of the abomasum. The survival rate of cows with abomasal torsion decreased as the base-excess concentration decreased(P=0.08). There was a significant difference(P<0.025) among base-excess ranges between abomasal torsion and right-side displacement of the abomasum. Most cows with base-excess concentrations ${\geq}15.0mEq/L$ and ${\leq}-0.5mEq/L$ had abomasal torsion, rather than right-side displacement of the abomasum.

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Interaction of Cyclohexane-Methyl Acetate Binary System through Dielectric Properties at Different Temperatures (다른 온도에서 유전 특성을 통한 사이클로헥산-메틸 아세테이드 바이너리 시스템의 상호관계)

  • Kamble, Siddharth P.;Sudake, Y.S.;Patil, S.S.;Khirade, P.W.;Mehrotra, S.C.
    • Journal of the Korean Chemical Society
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    • v.55 no.3
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    • pp.373-378
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    • 2011
  • The present paper reports the study of binary mixtures and their properties over the entire range of composition at temperatures 288, 298, 308 and 318 K. Excess dielectric constant, excess molar volume, excess refractive index, molar refraction and excess molar refraction at different temperatures have been computed from the experimentally measured values of the aforesaid parameters and fitted to the Redlich-Kister equation. Excess dielectric constant, excess molar volume excess molar polarizations are negative whereas excess refractive indices are positive over entire mole fraction of methyl acetate for all temperatures. The results are discussed in light of intermolecular interactions occurring in the binary mixture. Estimated coefficients of the Redlich-Kister polynomials and the standard error along the coefficients are also reported.

The Effect of Excess Calcium on the Iron Bioavailability and Bone Growth of Marginally Iron Deficient Rats (고 칼슘 섭취가 철이 부족한 성장기 흰쥐의 철 이용성과 뼈 성장에 미치는 영향)

  • 장순옥;김기대;이성현
    • Journal of Nutrition and Health
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    • v.37 no.8
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    • pp.645-654
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    • 2004
  • This study examined the effect of excess calcium (Ca) on the iron (Fe) bioavailability and bone growth of marginally Fe deficient animals. Two groups of weanling female SD rats were fed either normal Fe (35 ppm) or Fe deficient diet (8 ppm) for 3 weeks. Then each group of animals were assigned randomly to one of three groups and were fed one of six experimental diets additionally for 4 weeks, containing normal (35 ppm) or low (15 ppm) Fe and one of three levels of Ca as normal (0.5%), high (1.0%), or excess (1.5%). Feces and urine were collected during the last 3 days of treatment. After sacrifice blood, organs, and femur bone were collected for analysis. Final body weight and average food intake were not affected by either the levels of dietary Ca or Fe. Low Fe diet significantly reduced the level of serum ferritin, however, for Hb, Hct, and TIBC no difference was shown than those in the normal Fe group. TIBC increased slightly by high and excess Ca intake in low Fe groups. For both normal and low Fe groups, high and excess Ca intakes reduced the apparent absorption of Fe and Fe contents of liver significantly (p < 0.05). Calcium contents in kidney and Femur of rats that were fed high and excess levels of Ca were significantly greater than those of normal Ca groups. However, weight, length, and breaking force of the bone were not affected by increased Ca intakes. Both in control and low Fe groups, high and excess intakes of Ca decreased the apparent absorption of Ca. These results indicate that the excess intakes of calcium than the normal needs would be undesirable for Fe bioavailability and that the adverse effects be more serious in marginally iron deficient growing animals. In addition bone growth and strength would not be favorably affected by high Ca intakes, though, the long term effect of increased Ca contents in bone requires further examination.

Evaluation of Validity of Deficiency and Excess Pattern Identification Questionnaire (검진용 허실 변증 진단 설문지 타당도 평가)

  • Baek, Younghwa;Jung, Kyungsik;Kim, Yunyoung;Jang, Eunsu
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.34 no.3
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    • pp.142-148
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    • 2020
  • The purpose of this study was to evaluate the validity of Deficiency and Excess Pattern Identification Questionnaire. The number of subjects enrolled in this study was 431. Pearson Correlation Coefficient analysis were conducted to reveal the correlation among Deficiency and Excess Pattern Identification Questionnaire, Grip Strength and Quality of life. ROC-curve analysis were used to suggest optimal cut off value. Cohen Kappa also used to analyze for diagnostic validity. The significant p-value was < .05. The Deficiency questionnaire had positive correlation with the score of the expert and negative correlation with Grip Strength and Quality of life (p<.001). The Excess questionnaire had positive correlation with the score of the expert and negative correlation with Quality of life (p<.001). The optimal cut off value was 56.5 to separate deficiency and non deficiency and 47.5 to separate excess and non-excess. Furthermore, AUC was .900 and .851 accordingly. Cohen Kappa value between deficiency questionnaire and the expert was .640. Cohen Kappa value between excess questionnaire and the expert was .513. This study reveals that Deficiency and Excess Pattern Identification Questionnaire is valid. However, further study considering of gender, age, and health condition and so on, is needed.

Borehole stability analysis in oil and gas drilling in undrained condition

  • Wei, Jian-Guang;Yan, Chuan-Liang
    • Geomechanics and Engineering
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    • v.7 no.5
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    • pp.553-567
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    • 2014
  • Borehole instability during drilling process occurs frequently when drilling through shale formation. When a borehole is drilled in shale formation, the low permeability leads to an undrained loading condition. The pore pressure in the compressed area near the borehole may be higher than the initial pore pressure. However, the excess pore pressure caused by stress concentration was not considered in traditional borehole stability models. In this study, the calculation model of excess pore pressure induced by drilling was obtained with the introduction of Henkel's excess pore pressure theory. Combined with Mohr-Coulumb strength criterion, the calculation model of collapse pressure of shale in undrained condition is obtained. Furthermore, the variation of excess pore pressure and effective stress on the borehole wall is analyzed, and the influence of Skempton's pore pressure parameter on collapse pressure is also analyzed. The excess pore pressure decreases with the increasing of drilling fluid density; the excess pore pressure and collapse pressure both increase with the increasing of Skempton's pore pressure parameter. The study results provide a reference for determining drilling fluid density when drilling in shale formation.

Dynamic Analysis of Gravity Quay Wall Considering Development of Excess Pore Pressure in Backfill Soil (과잉간극수압 발생을 고려한 중력식 안벽구조물의 동적해석)

  • Ryu, Moo-Sung;Hwang, Jai-Ik;Kim, Sung-Ryul
    • Journal of Ocean Engineering and Technology
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    • v.24 no.5
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    • pp.39-47
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    • 2010
  • In this paper, a total stress analysis method for gravity quay walls is suggested. The method can evaluate the displacement of the quay walls considering the effect of excess pore pressure developed in backfill soils. This method changes the stiffness of backfill soils according to the expected magnitude of the excess pore pressure. For practical application, evaluation methods are suggested for determining the excess pore pressure ratio developed in the backfill soils and the backfill stiffness that corresponds to the excess pore pressure ratio. This method is important in practical applications because the displacement of the quay walls can be evaluated by using only the basic input properties in the total stress analysis. The applicability of the suggested method was verified by comparing the results of the analysis with the results of 1-g shaking table tests. From the comparison, it was found that the calculated displacements from the suggested method showed good agreement with the measured displacements of the quay walls. It was also found that the excess pore pressure in backfill soils is a governing influence on the dynamic behavior of quay walls.

A Study on the CdTe Single Crystal Growth by Vertical Bridgman Method (수직 Bridgman 법에 의한 CdTe 단결정 성장에 관한 연구)

  • Lee, Jong-Ki;Kim, Wook;Baik, Hong-Koo
    • Journal of Korea Foundry Society
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    • v.10 no.4
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    • pp.324-331
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    • 1990
  • The single crystal of CdTe was grown by modified 6 zone Bridgman method under the conditions of excess Te and excess Cd. To prevent the constitutional supercooling, the crystal growth was done under the temperature gradient of $17^{\circ}C/cm$ in front of the solid /liquid interface and the growth rate was 3mm/hr. The grain morphologies and the growth mechanism were investigated in excess Te and excess Cd conditions. The grain size of excess Te crystal was increased with an increase of the distance from the tip but, in the case of excess Cd crystal, single crystal was not obtained because of the cavities due to the excess Cd vapors so that the grain size was not increased with an increase of the distance from the tip. In addition, the growth of single crystal of CdTe was done with repeated necking ampoule. It was found that the necking had no effects on the grain selection because the cavities trapped in the necking portion acted as heterogeneous nucleation sites.

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