• 제목/요약/키워드: Pressure Gain

검색결과 309건 처리시간 0.031초

개별적 저 나트륨 투석 액 적용이 말기 신부전증 환자의 혈압, 투석 간 체중 증가, 갈증 및 투석 중 불편감에 미치는 영향 (Effect of Individual Low Sodium Dialysate on Blood Pressure, Interdialytic Weight Gain, Thirst and Intradialytic Discomfort In End-Stage Renal Disease Patients)

  • 김상숙;최영실
    • Journal of Korean Biological Nursing Science
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    • 제21권3호
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    • pp.169-177
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    • 2019
  • Purpose: The purpose of this paper was to identify blood pressure, interdialytic weight gain, thirst and intradialytic discomfort in subjects after applying individual low-sodium dialysis fluid (1,2,3 mEq/L) to hemodialysis patients for 12 weeks. Methods: This study was a non-equivalent pre-post design. For 12 weeks, dialysate concentration was maintained at 1 mEq/L or 2 mEq/L or 3 mEq/L based on average sodium concentration of each individual, and the difference was compared after applying individually. Results: Change in blood pressure significantly decreased in the group where in pre-hemodialysis systolic pressure decreased the gradient of sodium concentration in serum sodium and dialysis solution by 2mEq/L. Interdialytic weight gain, and thirst showed significant decrease in all three groups. But in all three groups, intradialytic discomfort among dialysis showed no significant changes. Conclusion: Although application of low sodium dialysis fluid showed no change in intradialytic discomfort, lowered blood pressure, thirst, and interdialytic weight gain, which could be used for individual showing increased interdialytic weight gain and increased blood pressure. There is need for continued study on this.

XeCl 레이저 증폭기의 활성기체 압력에 따른 포화 에너지 밀도와 소신호 이득계수 측정 (Measurements of Saturation Energy Denity and Small Signal Gain Coefficient Dependent on the Active Gas Pressure in XeCl Laser Amplifier)

  • 김규옥;김용평
    • 한국광학회지
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    • 제5권4호
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    • pp.457-460
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    • 1994
  • XeCl 레이저 증폭기의 포화 에너지 밀도와 소신호 이득계수를 활성기체의 압력을 변화시키면서 측정하였다. Xe이 30mb, He이 2000mb일 때, HCl이 34, 52, 73, 92으로 압력이 높아짐에 따라 포화 에너지 밀도는 1.3, 1.45, 2.0, $2.3mJ/\textrm{cm}^2$로 거의 선형적으로 증가하였지만 소신호 이득계수는 6.5, 7.5, 7.0, 7.0%/cm로 거의 변화하지 않았다.

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서보밸브 스풀-슬리브 형상공차가 압력 정특성에 미치는 영향 연구 (Effect of Spool-Sleeve Geometry on Static Pressure Characteristics of Servo Valves)

  • 김성동;손성회;함영복
    • 드라이브 ㆍ 컨트롤
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    • 제13권1호
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    • pp.34-42
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    • 2016
  • This study studied how the clearance, overlap and mismatch errors of spool-sleeve affect the static pressure characteristics of a servo valve. A computer simulation model was established as a direct acting servo valve and a series of simulations was conducted for various values of clearance, overlap and mismatch errors. Pressure gain decreased as the clearance increased. The overlap also affects the pressure gain and was similar to the effect of clearance. Asymmetry of the pressure plot got worse and worse as the mismatch error increased.

추진기관 혁신적 연비향상을 위한 승압연소기 개요 및 연구동향 (Introduction to Pressure Gain Combustors for the Game-Changing SFC Improvement in Propulsion Systems)

  • 최정열
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
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    • pp.301-302
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    • 2012
  • During a last decade, detonative combustion is promising combustion mechanism of high-speed propulsion systems, but is more rigorously considered in these days as a game-changer for the improvement of thermodynamic efficiency of propulsion and power generation systems. Regardless of the skepticism about the pressure loss associated with the strong shock waves, it is shown that the additional compression by the strong shock wave exhibits increased thermodynamics efficiency that is not achievable by conventional compression systems. Present talk will give an introduction to the concepts and the recent activities on the pressure gain combustors (PGC) researches based on detonation phenomena.

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말기신부전증 환자에서 혈액투석액 나트륨 농도가 혈압, 투석간 체중증가 및 갈증에 미치는 영향 (The Effect of Hypertonic Dialysate on Hemodynamic Parameters (blood pressure, pulse rate, ultrafiltration rate), Interdialytic Weight Gain and the Incidence of Thirst with Hemodialysis Patients)

  • 박혜자;장은정;김미경;조남미
    • 성인간호학회지
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    • 제12권1호
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    • pp.88-98
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    • 2000
  • Hemodialysis(HD)-associated hypotension is a frequent complication, but it is difficult to manage. Until now, several maneuvers have been tried to prevent the HD-associated hypotension. Of these, the sodium content of dialysate was regarded as an important factor for maintaining blood pressure during HD. In this study, we evaluated the effect of hypertonic dialysate on blood pressure, interdialytic weight gain and the incidence of thirst. The study was done for 6 weeks successively with 3 different groups. Each patient was dialysed with 3 different dialysates for 2 weeks: Group I(Conventional HD: sodium concentration: 137 mEq/L), Group II(Hypertonic HD: 147 mEq/L) and Group III (Sequential HD: from 147 to 140 mEq/L). Hemodynamic parameters(blood pressure, pulse rate and ultrafiltration rate), biochemical parameters(hematocrits, blood urea nitrogen, creatinine, osmolality, sodium, potassium, chloride, fasting blood sugar) and complications (interdialytic weight gain & thirsty sensation) were compared among 3 groups. The results were as follows: 1. Decline of systolic blood pressure and diastolic blood pressure at the time of a 3 hour check during hemodialysis was lower in the Group II than Group I and III (p=0.002; p=0.012). and decline of diastolic blood pressure at the time of a 4 hour check during hemodialysis was lower in the Group II and III than Group I (p=0.04). 2. Incidence of hypotensive episodes during dialysis was significantly lower in Group II than group I (p=0.0287). 3. The ultrafiltration in Group III at the time of 1 hour, 2 hour and 3 hour check during hemodialysis was higher than that in Group I and II at the time of 1 hour, 2 hour and 3 hour check during hemodialysis respectively (p=0.0001; p=0.0001; p=0.0004). 4. Interdialytic weight gain was higher in Group I($3.1{\pm}0.8$) than Group I($2.8{\pm}0.8$) and III ($2.9{\pm}0.9$) (p=0.0422). 5. Hematologic and biochemical results were not significantly different among 3 Groups. 6. Frequency of thirst was different in Group I, II and III, $0.05{\pm}0.12$, $0.41{\pm}0.24$and $0.22{\pm}0.29$ respectively (p=0.0259). The results suggest that hypertonic HD was effective in preventing HD-associated hypotension but interdialytic weight gain and thirst sensations were increased as compared with a conventional method. In this situation, sequential HD seems to be an alternative method to minimizes the side effect of hypertonic HD.

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Atmospheric Pressure Plasma Research Activity in Korea

  • Uhm, Han S.
    • 한국표면공학회지
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    • 제34권5호
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    • pp.367-377
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    • 2001
  • Plasma is generated by electrical discharge. Most plasma generation has been carried out at low-pressure gas typically less than one millionth of atmospheric pressure. Plasmas are in general generated from impact ionization of neutral gas molecules by accelerated electrons. The energy gain of electrons accelerated in an electrical field is proportional to the mean free path. Electrons gain more energy at low-pressure gas and generate plasma easily by ionization of neutrals, because the mean free path is longer. For this reason conventional plasma generation is carried out at low pressures. However, many practical applications require plasmas at high-pressure. In order to avoid the requirement for vacuum pumps, researchers in Korea start to develop plasmas in high-pressure chambers where the pressure is 1 atmosphere or greater. Material processing, environmental protection/restoration and improved energy production efficiency using plasmas are only possible for inexpensive bulk plasmas. We thus generate plasmas by new methods and plan to set foundations for new plasma technologies for $21^{st}$ / century industries. This technological research will play a central role in material processing, environmental and energy production industries.

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광고 프레이밍 유형과 브랜드 애착의 관계 연구 (The Relationship between Type of Ad Framing and Brand Attachment)

  • 홍재원;박승배;우상철
    • 한국컴퓨터정보학회:학술대회논문집
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    • 한국컴퓨터정보학회 2019년도 제59차 동계학술대회논문집 27권1호
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    • pp.191-192
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    • 2019
  • The objective of this study is to understand the relationship between type of advertising and brand attachment. We divide advertising type into loss and gain frame and examine the effect on brand attachment, The effect of scarcity advertising on brand attachment and the effects of interaction effects on brand attachment were examined. The results showed that the effect of the loss and gain frame on brand attachment was not statistically significant. It also showed that scarcity was not emphasized or emphasized or had no effect on brand attachment. That is, the more emphasis on gain in advertising frame and the less pressure on scarcity, the more effective ad type for brand attachment.

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고압 고온 수증기에서 지르칼로이-4 산화반응 정량화 및 사고해석에의 응용 (Zricaloy-4 Oxidation Kinetics in High-Pressure High-Temperature Steam and Application to Accident Analysis)

  • 박광헌
    • 한국표면공학회지
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    • 제35권6호
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    • pp.363-370
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    • 2002
  • Empirical equations for the oxide thickness and the weight gain of Zircaloy-4 cladding during the oxidation in high temperature, high pressure steam have been developed. Firstly, the empirical equations for oxide thickness in 1 atm steam in 700~100$0^{\circ}C$ were made, then, the enhancement factor for the steam pressure effects on Zircaloy-4 cladding oxidation in high temperature steam was added. Based on the analysis of the weight fraction of dissolved oxygen in metal layer, empirical equations for the weight gain of Zircaloy-4 in high pressure, high temperature steam were developed. We compare the developed empirical equations with the Baker-Just correlation. The Baker-Just correlation can give a non-conservative estimation of oxidation of Zircaloy-4, depending on the steam pressure. These developed empirical equations can be used for the correct estimation of oxidation of Zircaloy-4 during accident analysis.

Enhancement of durability of tall buildings by using deep-learning-based predictions of wind-induced pressure

  • K.R. Sri Preethaa;N. Yuvaraj;Gitanjali Wadhwa;Sujeen Song;Se-Woon Choi;Bubryur Kim
    • Wind and Structures
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    • 제36권4호
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    • pp.237-247
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    • 2023
  • The emergence of high-rise buildings has necessitated frequent structural health monitoring and maintenance for safety reasons. Wind causes damage and structural changes on tall structures; thus, safe structures should be designed. The pressure developed on tall buildings has been utilized in previous research studies to assess the impacts of wind on structures. The wind tunnel test is a primary research method commonly used to quantify the aerodynamic characteristics of high-rise buildings. Wind pressure is measured by placing pressure sensor taps at different locations on tall buildings, and the collected data are used for analysis. However, sensors may malfunction and produce erroneous data; these data losses make it difficult to analyze aerodynamic properties. Therefore, it is essential to generate missing data relative to the original data obtained from neighboring pressure sensor taps at various intervals. This study proposes a deep learning-based, deep convolutional generative adversarial network (DCGAN) to restore missing data associated with faulty pressure sensors installed on high-rise buildings. The performance of the proposed DCGAN is validated by using a standard imputation model known as the generative adversarial imputation network (GAIN). The average mean-square error (AMSE) and average R-squared (ARSE) are used as performance metrics. The calculated ARSE values by DCGAN on the building model's front, backside, left, and right sides are 0.970, 0.972, 0.984 and 0.978, respectively. The AMSE produced by DCGAN on four sides of the building model is 0.008, 0.010, 0.015 and 0.014. The average standard deviation of the actual measures of the pressure sensors on four sides of the model were 0.1738, 0.1758, 0.2234 and 0.2278. The average standard deviation of the pressure values generated by the proposed DCGAN imputation model was closer to that of the measured actual with values of 0.1736,0.1746,0.2191, and 0.2239 on four sides, respectively. In comparison, the standard deviation of the values predicted by GAIN are 0.1726,0.1735,0.2161, and 0.2209, which is far from actual values. The results demonstrate that DCGAN model fits better for data imputation than the GAIN model with improved accuracy and fewer error rates. Additionally, the DCGAN is utilized to estimate the wind pressure in regions of buildings where no pressure sensor taps are available; the model yielded greater prediction accuracy than GAIN.

유량제어용 서보밸브와 비례방향밸브의 압력신호를 이용한 정적 성능 진단에 관한 연구 (Static Performance Diagnosis Based on Pressure Signal for a Flow Control Servovalve or Proportional Direction Valve)

  • 김성동;전세형;김인동;함영복
    • 드라이브 ㆍ 컨트롤
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    • 제9권4호
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    • pp.32-41
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    • 2012
  • Most diagnosis methods for servo valves requires installing spool displacement sensor or flow sensor as well as pressure sensor. The measurement of flow is hard to implement and many kinds of servovalves or proportional direction valves do not have a built-in spool displacement sensor. In this study, static performances of servovalve or proportional-direction-valve are studied theoretically and a diagnosis technique, which uses only load pressure and input current signal, is assessed. An experimental setup was made based upon a personal computer and the LabVIEW graphical language. A series of diagnosis tests were performed and the analysis results showed it possible to measure the pressure gain, hysteresis and null bias in a relatively simple methodology.