Translaminar Pressure Difference

2019 ◽  
pp. 21-23
Author(s):  
Lina Siaudvytyte
Keyword(s):  
Pressure Difference

Dependence of Blood Clot Lysis on the Mode of Transport of Urokinase into the Clot - A Magnetic Resonance Imaging Study in Vitro

1991 ◽  
Vol 65 (05) ◽  
pp. 549-552 ◽  
Author(s):  
A Blinc ◽  
G Planinšič ◽  
D Keber ◽  
O Jarh ◽  
G Lahajnar ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Pressure Difference ◽  
Volume Flow Rate ◽  
Blood Clot ◽  
Linear Regression Analysis ◽  
Imaging Study ◽  
Clot Lysis ◽  
Resonance Imaging

SummaryMagnetic resonance imaging was employed to study the dependence of clot lysing patterns on two different modes of transport of urokinase into whole blood clots. In one group of clots (nonperfused clots, n1 = 10), access of urokinase to the fibrin network was possible by diffusion only, whereas in the other group (perfused clots, n2 = 10) bulk flow of plasma containing urokinase was instituted through occlusive clots by a pressure difference of 3 .7 kPa (37 cm H2O) across 3 cm long clots with a diameter of 4 mm. It was determined separately that this pressure difference resulted in a volume flow rate of 5.05 ± 2.4 × 10−2 ml/min through occlusive clots. Perfused clots diminished in size significantly in comparison to nonperfused ones already after 20 min (p <0.005). Linear regression analysis of two-dimensional clot sizes measured by MRI showed that the rate of lysis was more than 50-times faster in the perfused group in comparison to the nonperfused group. It was concluded that penetration of the thrombolytic agent into clots by perfusion is much more effective than by diffusion. Our results might have some implications for understanding the differences in lysis of arterial and venous thrombi.

INTERARM SYSTOLIC BLOOD PRESSURE DIFFERENCE IS ASSOCIATED WITH A HIGH PREVALENCE OF CARDIO VASCULAR DISEASES- A CROSS-SECTIONAL STUDY IN POLICE WORKER

2020 ◽  
Vol 4 (11) ◽  
Author(s):  
Somesh Raju ◽  
Rina Kumari ◽  
Sunita Tiwari ◽  
NS Verma
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Blood Sugar ◽  
Pressure Difference ◽  
Systolic Pressure ◽  
Working Environment ◽  
Vascular Events ◽  
Cross Sectional ◽  
Blood Pressure Difference ◽  
High Prevalence

Background: Interarm systolic blood pressure difference more than 10 mm of Hg is predictor of cardiovascular and metabolic risk. Despite of sufficient physical activity there is high prevalence of obesity in police personal because of stressful working environment. No studies have addressed the significance of interarm pressure difference among them. Therefore, the present study conducted to access the relation of interarm blood pressure difference with obesity in police personnel. Aims and Objective: To estimate the interarm pressure difference in police personal to see its association with their obesity. Material and Method: This cross-sectional observational study done on 245 police workers in PAC, Sitapur, India. Subjects having more than ten years of working experience were included in study. Anthropometric measurements of subject recorded by following standard protocol. Measurement of systolic pressure in both arm recorded simultaneously by mercury sphygmomanometer. Available data analyze and expressed in percentage, mean with SD and chi square test to see the significance of association. Results: According to anthropometric results of subjects 77.14 prcent subjects were having generalised obesity and 82.04 percent of subjects having abdominal obesity. 34.29 percent of subjects showed abnormally high (?10 mmHg) inter-arm systolic blood pressure difference. Both type of obesity showed positive association with blood sugar level but no association with interarm pressure difference. Conclusion: Interarm blood pressure difference is greater in individual having obesity or prolong duration of service. Such subjects are more susceptible to develop coronary artery disease or peripheral arterial disease in future. Early screening can help to detect the vascular events likely to occur in the future Keywords: Body mass index, Waist circumference, Interarm pressure difference, Random blood sugar

scholarly journals Effects of Blade Parameters on the Flow Field and Classification Performance of the Vertical Roller Mill via Numerical Investigations

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Chang Liu ◽  
Zuobing Chen ◽  
Weili Zhang ◽  
Chenggang Yang ◽  
Ya Mao ◽  
...  
Keyword(s):  
Flow Field ◽  
Pressure Difference ◽  
Continuous Phase ◽  
Classification Performance ◽  
Field Analysis ◽  
Discrete Phase Model ◽  
Roller Mill ◽  
Discrete Phase ◽  
Vertical Roller ◽  
Classification Efficiency

The vertical roller mill is an important crushing and grading screening device widely used in many industries. Its classification efficiency and the pressure difference determine the entire producing capacity and power consumption, respectively, which makes them the two key indicators describing the mill performance. Based on the DPM (Discrete Phase Model) and continuous phase coupling model, the flow field characteristics in the vertical roller mill including the velocity and pressure fields and the discrete phase distributions had been analyzed. The influence of blade parameters like the shape, number, and rotating speed on the flow field and classification performance had also been comprehensively explored. The numerical simulations showed that there are vortices in many zones in the mill and the blades are of great significance to the mill performance. The blade IV not only results in high classification efficiency but also reduces effectively the pressure difference in the separator and also the whole machine. The conclusions of the flow field analysis and the blade effects on the classification efficiency and the pressure difference could guide designing and optimizing the equipment structure and the milling process, which is of great importance to obtain better overall performance of the vertical roller mill.

Rotor Wake Generated Unsteady Aerodynamic Response of a Compressor Stator

1978 ◽  
Vol 100 (4) ◽  
pp. 664-675 ◽  
Author(s):  
S. Fleeter ◽  
R. L. Jay ◽  
W. A. Bennett
Keyword(s):  
Pressure Difference ◽  
Second Harmonic ◽  
Incidence Angle ◽  
Dynamic Pressure ◽  
Pressure Differential ◽  
Phase Lag ◽  
Trailing Edge ◽  
Unsteady Pressure ◽  
Forcing Function ◽  
Reduced Frequency

An experimental investigation was conducted to determine the fluctuating pressure distribution on a stationary vane row, with the primary source of excitation being the wakes from the upstream rotor blades. This was accomplished in a large scale, low speed, single stage research compressor. The forcing function, the velocity defect created by the rotor wakes, was measured with a crossed hot-wire probe. The aerodynamic response on the vanes was measured by means of flush mounted high response dynamic pressure transducers. The dynamic data were analyzed to determine the chordwise distribution of the dynamic pressure coefficient and aerodynamic phase lag as referenced to a transverse gust at the vane leading edge. Vane suction and pressure surface data as well as the pressure difference across the vane were obtained for reduced frequency values ranging from 3.65 to 16.80 and for an incidence angle range of 35.5 deg. The pressure difference data were correlated with a state-of-the-art aerodynamic cascade transverse gust analysis. The correlation was quite good for all reduced frequency values for small values of incidence. For the more negative incidence angle data points, it was shown that a convected wake phenomena not modeled in the analysis existed. Both the first and second harmonic unsteady pressure differential magnitude data decrease in the chordwise direction. The second harmonic magnitude data attains a value very nearly zero at the vane trailing edge transducer location, while the first harmonic data is still finite, albeit small, at this location. That the magnitude of the unsteady pressure differential data approaches zero near to the trailing edge, particularly the second harmonic data which has reduced frequency values to 16.8, is significant in that it reflects upon the validity of the Kutta condition for unsteady flows.

scholarly journals Study on the Leakage and Inter-Stage Pressure Drop Characteristics of Two-Stage Finger Seal

2021 ◽  
Vol 11 (5) ◽  
pp. 2239
Author(s):  
Hailin Zhao ◽  
Hua Su ◽  
Guoding Chen ◽  
Yanchao Zhang
Keyword(s):  
Pressure Drop ◽  
Pressure Difference ◽  
Radial Displacement ◽  
Mean Square ◽  
The Finite Element Method ◽  
Axial Pressure ◽  
Two Stage ◽  
One Stage ◽  
The One ◽  
Lower Contact

To solve the high leakage and high wear problems faced by sealing devices in aeroengines under the condition of high axial pressure difference, the two-stage finger seal is proposed in this paper. The finite element method and computational fluid dynamics (FEM/CFD) coupling iterative algorithm of the two-stage finger seal is developed and validated. Then the performance advantages of two-stage finger seal compared to the one-stage finger seal are studied, as well as the leakage and the inter-stage pressure drop characteristics of two-stage finger seal are investigated. Finally, the measure to improve the inter-stage imbalance of pressure drop of two-stage finger seal is proposed. The results show that the two-stage finger seal has lower leakage and lower contact pressure than the one-stage finger seal at high axial pressure difference, but there exists an inter-stage imbalance of pressure drop. Increasing the axial pressure difference and the root mean square (RMS) roughness of finger element can aggravate the imbalance of pressure drop, while the radial displacement excitation of rotor has little influence on it. The results also indicate that the inter-stage imbalance of pressure drop of the two-stage finger seal can be improved by increasing the number of finger elements of the 1st finger seal and decreasing the number of finger elements of the 2nd finger seal.

scholarly journals Diastolic Pressure Difference to Classify Pulmonary Hypertension in the Assessment of Heart Transplant Candidates

2017 ◽  
Vol 10 (9) ◽  
Author(s):  
Stephen P. Wright ◽  
Yasbanoo Moayedi ◽  
Farid Foroutan ◽  
Suhail Agarwal ◽  
Geraldine Paradero ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Heart Transplant ◽  
Pressure Difference ◽  
Diastolic Pressure ◽  
Transplant Candidates
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