Modern practice of solving the problems of heat supply system design generates the need to solve the problem of choosing optimal parameters for a considerable set of equipment. The problem of choosing optimal parameters involves determining the diameters of new heat pipelines, searching for the methods to reconstruct existing network sections, and choosing the pressure heads of pumping stations...

[1] In the past, texture-based classification of soils has been used for grouping soils in variably saturated water flow and solute transport studies. Classification of soils becomes especially important for large-scale studies where the spatial and temporal variability in the hydraulic properties of soils exceeds the field sampling capabilities. Although soiltexture-based classification has be...

PROBLEM This study aimed to provide an assessment of the contribution of design to the occurrence of fatal work-related injuries in Australia. METHODS The Australian National Coroners' Information System was the data source for fatal injuries. Deaths resulting from workplace injuries on or between 1 July 2000 and 30 June 2002 were included. RESULTS Seventy seven (37%) of the 210 identified ...

The proper performance of micro-manipulative techniques depends upon three main factors: a good viexv of the procedure; properly designed tools wvhich can be held in the hand yet have accurate and efficient working ends; a relaxed position so that the operator avoids spending energy fighting against gravity. Mluch thought and experience is being displayed in the introduction of microscopes and ...

In this paper, the hydraulic and heat-transfer properties of two sets of artificially fractured granite samples are investigated. First, the morphological information is determined using 3D modelling technology. The area ratio is used to describe the roughness of the fracture surface. Second, the hydraulic properties of fractured granite are tested by exposing samples to different confining pre...

Hydraulic cylinder actuators are used extensively in industrial, construction and agricultural works. The small sized outlet ports of the cylinders resist the flow of discharged oil; and as a result the piston motion is slowed down. This causes a lot of heat generation and energy loss within the actuators. The study investigates and analyzes the possibilities of reducing the hydraulic resistanc...

The concept of a hydraulic axis plays a central role within the design and analysis of hydraulic systems. A hydraulic axis comprises working, control, and supply elements that realize a subfunction of a hydraulic system. Analyzing a system’s functional structure means to identify the hydraulic axes along with their couplings. The paper in hand addresses this problem; it presents concepts and al...

1 Abstract The paper presents a hydraulic astable multivibrator system. The system consists of hydraulic resistors, hydraulic capacitors and hydraulic pressure controlled valves. The system is designed, realised and tested. The measured system behaviour agrees well with the model simulations. The free running frequency of the multivibrator is 0.18 Hz and the output pressure swing is 90% of the ...

Hydraulic excavator energy saving is important to relieve source shortage and protect environment. This paper mainly discusses the energy saving for the hybrid hydraulic excavator. By analyzing the excess energy of three hydraulic cylinders in the conventional hydraulic excavator, a new boom potential energy recovery system is proposed. The mathematical models of the main components including b...