• Title/Summary/Keyword: Pressure Curve

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Behavior of Excessive Pore Water Pressure with Embankment on Soft Ground (연약지반의 성토에 따른 과잉간극수압의 거동)

  • 김지훈;강예묵;이달원;임성훈
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 1999.10c
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    • pp.588-593
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    • 1999
  • This study were performed to investigated the behavior of excessive pore water pressure with embankment of soft clay. The dissipation behavior of excessive pore water pressure in the improved and non-improved area was used to compare and alyze with lateral displacement , and to investigated the applicability of the methods for stability evaluatio of soft clay. The behavior of excess pore water pressure could be used to the fundamental data for stability evaluation, and the evaluation of the stability of embankment was recommended to use the indlination of curve rather than critical line.

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The Effect of Seepage Forces on the Ground Reaction Curve of Tunnel (침투력이 터널의 지반반응곡선에 미치는 영향)

  • Lee Seok-Won;Jung Jong-Won;Nam Seok-Woo;Lee In-Mo
    • Journal of the Korean Geotechnical Society
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    • v.21 no.3
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    • pp.87-98
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    • 2005
  • When a tunnel is excavated below groundwater table, the groundwater flows into the excavated wall of tunnel and seepage forces are acting on the tunnel wall. The ground reaction curve is defined as the relationship between internal pressure and radial displacement of tunnel wall. Therefore, the ground reaction curve is significantly affected by seepage forces. In this study, the theoretical solutions of ground reaction curves were derived for both the dry condition and the seepage forces. The theoretical solutions derived were validated by numerical analysis. The ground reaction curves with the support characteristic curve were also analyzed in various conditions of groundwater table. Finally, the theoretical solutions of the ground reaction curve derived in this study can be utilized easily to determine the appropriate time of support systems, the stiffness of support system and so forth for the reasonable design.

Evaluation of J-R Curve and Tmat of SA 508C-3 Steel at Elevated Temperature (SA 508C-3강의 고온에서 J-R Curve 및 Tmat의 평가)

  • Lim, Man-Bae;Cha, Gee-Jun
    • Journal of Ocean Engineering and Technology
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    • v.12 no.3 s.29
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    • pp.60-67
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    • 1998
  • In this study, the J-Resistance Curve and material tearing modulus of SA508-C3 steel, which is one of the used nuclear pressure vessel steel, are measured ar room temperature, $200^{circ}C$ and $300^{circ}C$ according to load ratio analysis and ASTM E813, ASTM E1152, respectively. It is observed that J-R curve and Tmat value decrease as the temperature level increase. Applicability of $T_j$ proposed by Paris et al as instability parameter for ductile material is investigated. It is concluded that results are the $T_j$ parameter may be used as a crack instability parameter.

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The Development of Exclusive CAD/CAM System for Impeller Blades Formed by Ruled Surface I(A Study on the Modeling) (Ruled Surface로 형성된 임펠러 블레이드 전용 CAD/CAM 시스템 개발 I (모델링에 관한 연구))

  • ;;;;;;Yu-Ge Dong
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.10 no.6
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    • pp.71-77
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    • 2001
  • We have developed the exclusive CAD/CAM system for the machining of impeller blades. This study is about the mod-eling method for the effective machining of impeller blades farmed by ruled surface. As the impeller is consisted of boss part and blade part, the boss is modeled by rotational surface of hub curve on z-axis and the blade is described by ruled- surfaces between hub curve and shroud curve. This modeling process can be carried out on the software developed in this study. And, the developed software can describe the impeller as a solid model through interface with Solid-Works soul- ware. The developed software containing the interface method proposed in this study was very effective fur impeller modeling.

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Review on Floating Pulse and Sinking Pulse in the View Point of Tonometric Measurement (토노메트리 측정 관점에서의 부침맥 고찰)

  • Lee, Jeon;Lee, Yu-Jung;Ryu, Hyun-Hee;Lee, Hae-Jung;Kim, Jong-Yeol
    • Korean Journal of Oriental Medicine
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    • v.14 no.2
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    • pp.113-119
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    • 2008
  • In pulse diagnosis, floating pulse and sinking pulse are frequently used for diagnosis about where disease is located and how much severe they are. However, in what mechanism floating pulse and sinking pulse arise is not known well. There are two point of views on substantial of floating pulse and sinking pulse. The first one is the floating and sinking degrees is the expression on the depth of pulsation. And, the second one is floating and sinking pulse is based on the response of pulsation to the indent pressure on radial artery. In this paper, we discussed these two opinions in the view point of tonometric measurement. The process for diagnosis on floating pulse and sinking pulse is similar to the tonometric measurement for non invasive blood pressure or intraocular pressure. We modelled the degrees of depth of pulsation with different indent pressures for initial pulsation feeling and different slopes of indent pressure lines. From this modelling, we can confirm the effect of pulsation depth on P-H curve, that is, in the model where lower pulsation is assumed, the shift of optimal indent pressure to the right was observed. The response of pulse pressure to the indent pressure was tried to be modelled with the degrees of mean blood pressure. Consequently, we tried to model the phenomenon of floating and sinking pulse for the first. And, from this modelling, we can get abundant understanding on how floating and sinking pulse can be caused. In the further study, we want to prove the suitability of this tonometric measurement based modelling with various studies including ultrasound measurement for the depth of pulsation in different EMI subjects.

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Evaluations on the Characteristics of Pressure Drop f3r the Design of Intravascular Artificial Lung Assist Device (혈관 내 폐 보조장치 설계를 위한 압력손실 특성 평가)

  • 김기범;권대규;박재관;정경락;이삼철
    • Membrane Journal
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    • v.13 no.1
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    • pp.20-28
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    • 2003
  • In this study, we try to formularize simultaneous equations to make a prediction about pressure drop for designing intravascular artificial lung assist device. Designing parameters to predict the effect of pressure drop and designed modules under various conditions were studied through an experimental modeling before inserting the artificial lung assist device into as venous. We measured pressure drop in various number of hollow fiber membranes, when the inside diameter of shell is fixed in 3 cm, and tried to develope the prediction equations by curve fitting based on the correlation between the experimental pressure drop and the device frontal area or packing density. The results showed that pressure drop increased with 2nd order functional formula as the liquid flow rate, the frontal area, and the packing density increased. Also, we can estimate the pressure drop as a function of the frontal area or packing density. The pressure drop obtained from the experiment was similar to that from the equation, confirming the usefulness of the equation.

Comparison of the Predictive Validity of the Pressure Injury Risk Assessment in Pediatric Patients: Braden, Braden Q and Braden QD Scale (소아 환자에서 욕창 위험도 사정 도구의 예측타당도 비교: Braden, Braden Q 및 Braden QD 도구)

  • Kang, Ji Hyeon;Lim, Eun Young;Lee, Nam Ju;Yu, Hye Min
    • Journal of Korean Clinical Nursing Research
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    • v.30 no.1
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    • pp.35-44
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    • 2024
  • Purpose: The purpose of this study is to compare the predictive validity of pressure injury risk assessment, Braden, Braden Q and Braden QD for pediatric patients. Methods: Prospective observational study included patients under the age of 19 who were hospitalized to general wards, intensive care units of a children's hospital. Characteristics related to pressure injury were collected, and predicted validity was compared by calculating the areas under the curve (AUC) of the Braden, Braden Q, and Braden QD scales. Results: A total of 689 patients were included in the study. A total of 13 (1.9%) patients had pressure injuries, and the number of pressure injuries was 17. Factors related to the occurrence of pressure injuries were 9 (52.9%) immobility-related and 8 (47.1%) medical device-related. The AUC for each scale was .91 (95% CI .89~.94) for Braden, .92 (95% CI .90~.95) for Braden Q, and .94(95% CI .92~.96) for Braden QD. The optimal cut-off points were identified as 16 for Braden (sensitivity=88.8%, specificity=86.4%), 17 for Braden Q(sensitivity=63.6%, specificity=94.9%), and 12 for Braden QD (sensitivity=94.4%, specificity=88.7%). Conclusion: The Braden QD scale demonstrated the highest predictive validity for pressure injuries in pediatric patients and is expected to be valuable tool in preventing pediatrics pressure injuries.

Analytical Application of Glow Discharge Atomic Absorption Spectroscopy (GD-AAS) Using Three Types of Jet Configurations Under Power Mode

  • Hwang, Jun Ho;Lee, Ki Beom;Kim, Min Su;Lee, Seong Ro;Kim, Hasuck;Kim, Hyo Jin;Lee, Gae Ho
    • Analytical Science and Technology
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    • v.8 no.4
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    • pp.443-448
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    • 1995
  • Three anode configurations of six-jet, cone-jet and cylindrical-jet are tested for their analytical performance under power mode operation. The effect of pressure, power and gas flow rate on atomic absorption signals have been studied. The increase of atomic absorption signal of sample element is observed at a fixed pressure in all configurations as the gas flow rate increase up to 300-600 seem, and as the power dissipated in the glow discharge cell increase. The lower the pressure is in the glow discharge cell at a fixed discharge power and argon flow rate, the greater the absorbance of sample element is. The optimum conditions are taken from these data and a calibration curve of Cu in low-alloy steel sample is obtained. In this calibration curve, six-jet configuration shows the best analytical results varies as the sample element.

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An Experimental Study on the Squeal Noise Generation due to Dynamic Instability of Brake Pad (브레이크 패드의 동적 불안정성에 따른 스퀼 소음 발생 원인의 실험적 연구)

  • Cho, Sangwoon;Lim, Byoungduk
    • Transactions of the Korean Society of Automotive Engineers
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    • v.24 no.5
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    • pp.520-526
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    • 2016
  • Squeal noise is a typical brake noise that is annoying to both passengers and pedestrians. Its frequency range is fairly wide from 1 kHz to 18 kHz, which can be distressful to people. The brake squeal noise occurs due to various mechanisms, such as the mode coupling of the brake system, self-excited vibration, unstable wear, and others. In this study, several parameters involved in the generation of a squeal noise are investigated experimentally by using a brake noise dynamometer. The speed, caliper pressure, torque, and friction coefficient are measured as functions of time on the dynamometer. The contact pressure and temperature distributions of the disc and the pad are also measured by using a thermal imaging camera and a pressure mapping system. As a result of the simultaneous measurement of the friction coefficient and squeal amplitude as functions of the velocity, it is found that the onset of the squeal may be predicted from the ${\mu}-v$ curve. It is also found that a non-uniform contact pressure causes instability and, in turn, a squeal. Based on the analysis results, design modifications of the pad are suggested for improved noise characteristics.

Effects of Cooking Time and HTST Air Dehydration Time on Physical Propertiesof Driet Green Peas

  • 김명환
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.19 no.3
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    • pp.195-200
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    • 1990
  • Effects of cooking time(5-30 min in a pressure cooker) and HTST air dehydratiion time(0-9min at 15$0^{\circ}C$) on physical properties of dried green peas(3% oisture content wet basis) were investigated by determining rehydration ratio rehydration curve browning reaction and puncture force, The rehydration ratio and curve of dried green peas were increased with increa-sing cooking time and HTST air dehydration time. Preheating of the green peas for 30 min in a pressure cooker or for 9 min of HTST air dehydration time prior to 6$0^{\circ}C$ air dehydration recovered a 87.3% of original moisture content of raw green peas in a boiling water for 5 min. The brownin greaction was gradually decreased up to 15 min of cooking time. Puncture pressure of rehydrated green peas treated in a boiling water for 5 min was decreased as the cooking time and HTST air dehydration time were increased and was highly correlated with rehydration (r=-0.956) The effects of cooking time and HTST air dehydration time on rehydration ratio browning reaction and puncture pressure were significantly different at the a=0.01 level except effect of HTST air dehydration time on browning reaction.

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