Paraffin wax exhibits a volumetric expansion of ∼15%, at around its melting point. By exploiting this phenomenon, high performance bulkachined electrothermal hydraulic microactuators have been demonstrated. The microactuators have been integrated into microfluidic valves, icrogrippers and micropipettes. The paraffin wax is confined within a bulk-micromachined silicon container. This container i...

Vertical hydraulic gradient is commonly measured in rivers, lakes, and streams for studies of groundwater-surface water interaction. While a number of methods with subtle differences have been applied, these methods can generally be separated into two categories; measuring surface water elevation and pressure in the subsurface separately or making direct measurements of the head difference with...

Relief valves are widely used in industrial machinery. Due to the outlet of the relief valve being connected to the tank, the pressure drop of the relief valve is frequently equal to the inlet pressure. Accordingly, the energy loss of the relief valve is very high in some cases and this will worsen with an increase in the rated pressure of the hydraulic system. In order to overcome the disadvan...

A monopropellant powered free piston hydraulic pump (FPHP) was designed as a human scale (1.0 to 3.0 kW) mobile robotics power supply. The FPHP utilized high concentration hydrogen peroxide, which decomposes into hot gas when exposed to a catalyst, as the monopropellant energy source. Energy was extracted from the hydrogen peroxide and transferred directly to hydraulic fluid by expanding the ho...

High servo control response and high energy-efficiency are requested in hydraulic servo systems of current hydraulic machines. This investigation concurrently implements energy-saving control and velocity-force control for simultaneously realizing high velocity-force control response and high energy-efficiency for hydraulic valve-controlled cylinder systems. The velocity-force control of the hy...

The design of hydraulic systems is founded on deep physical connections. It needs creativity and, at the present time, it cannot be automated. Nevertheless, powerful design support in hydraulics is still possible. This paper presents a new view to the design of hydraulic systems and shows how sophisticated subtasks of the hydraulic design procedure can be tackled. We identify the “model synthes...

in this paper, a finite element model is developed for the fully hydro-mechanical analysis of hydraulic fracturing in partially saturated porous media. the model is derived from the framework of generalized biot theory. the fracture propagation is governed by a cohesive fracture model. the flow within the fracture zone is modeled by the lubrication equation. the displacement of solid phase, and...

The role of plasma membrane aquaporins (PIPs) in water relations of Arabidopsis was studied by examining plants with reduced expression of PIP1 and PIP2 aquaporins, produced by crossing two different antisense lines. Compared with controls, the double antisense (dAS) plants had reduced amounts of PIP1 and PIP2 aquaporins, and the osmotic hydraulic conductivity of isolated root and leaf protopla...

ABSTRACT: Deceleration or stopping the vehicle without any diving and lateral acceleration is essential to develop an effective braking system. The hydraulic braking system with intelligent braking called Antilock Braking system (ABS) and Electronic Stability Control (ESC) has been introduced.  However, due to the insufficient human effort, the ABS and ESC to some extent, not function well...

We deal with a solid manifold block and a laminated manifold block that are used for connecting hydraulic components. They are useful for reducing the space and weight of hydraulic systems. We investigate pressure drops of their pipe flow with computational fluid dynamics (CFD) and compare those of two types. The majority of all pressure drops in both types is pressure drop at corners. In solid...