Myocardial active relaxation and restoring forces are known determinants of left ventricular (LV) diastolic function. We hypothesize the existence of an additional mechanism involved in LV filling, namely, a hydraulic force contributing to the longitudinal motion of the atrioventricular (AV) plane. A prerequisite for the presence of a net hydraulic force during diastole is that the atrial short...

This research adopts the quasi three-dimensional hydraulic design method for the impeller of high specific speed mixed-flow pump to achieve the purpose of verifying the hydraulic design method and improving hydraulic performance. Based on the two families of stream surface theory, the direct problem is completed when the meridional flow field of impeller is obtained by employing iterative calcu...

This paper describes and demonstrates an efficient method for online hydraulic state estimation in urban water networks. The proposed method employs an online predictor-corrector (PC) procedure for forecasting future water demands. A statistical data-driven algorithm (M5 Model-Trees algorithm) is applied to estimate future water demands, and an evolutionary optimization technique (genetic algor...

Tide-induced hydraulic head fluctuation results in significant airflow above the water table if the aquifer is air-confined, for example, if the aquifer is capped by low permeability materials. Hypothetical studies on the interaction between tidal fluctuation and airflow in coastal aquifers are carried out using an air–water two-phase numerical model. The results show that both the amplitude of...

Several potential network structures are chosen to do a large number of experimental analysis, historical data is divided into training sample and testing sample, and the corresponding neural network model is established with BP learning algorithm. After checking the testing sample, a superior network integration model which can be applied for hydraulic metal structure health grade diagnosing i...

High strength hydraulic concrete was introduced based on its thermo-dynamic and strain-stress characteristics. The compound exponential thermo-dynamic creep model was established. The temperature rise models were interpreted. The bisection constitutional model was deduced as the approach to express the strain-stress non-linearity of high strength hydraulic concrete. The key parameters on thermo...

In order to study the numerical control (NC) servo press hydraulic control system and its control algorithm. The numerical control servo press performance and control principle of hydraulic control system are analyzed. According to the flow equation of the hydraulic control valve, hydraulic cylinder flow continuity equation and the force balance equation of the hydraulic cylinder with load pres...

Abstract In general two basic methods are used for controlling the velocity of a hydraulic cylinder. First by an axial variable-displacement pump for controls flow to the cylinder. This configuration is commonly known as a hydrostatic transmission. Second by proportional valve powered by a constant-pressure source, such as a pressure compensated pump, drives the hydraulic cylinder. In this stud...

abstract the saturated hydraulic conductivity (ks) is an important physical property of soil. the direct measurement of this property in soils is a difficult and time consuming process. pedotransfer functions (ptfs) provide an alternative by estimating soil parameters from more readily available soil data. the objective of this study is to determine effective factors on soil hydraulic conductiv...

able information on relationships between size—expressed in terms of diameter and dry biomass—and hydraulic efficiency of woody structures at different scales, from stem segments to whole trees. Three data sets were constructed: the first described the relationship between segment diameter and hydraulic conductivity (kh; kg m s –1 MPa) in four species; the second, for the same four species, des...