This Paper has studied the oil supply characteristics to scroll compressors for package air conditioners. Scroll compressor has four major lubricating parts: the lower journal bearing, the main journal bearing, the orbiting scroll journal bearing and the thrust bearing between the orbiting scroll and the main frame. It is very important to supply the required flow rate of oil in order to preven...

This study attempts to search for the combination of the back pressure port size and its location which results in minimum mechanical losses and yet providing sufficient axial sealing. Theoretical study employing a mathematical model coupled with numerical optimisation algorithm predicted that a reduction of 9% in mechanical losses can be achieved. The main cause of gain that resulted in such a...

The scroll compressor, using R41 OA that has higher density and works at higher pressure than R22, is required to redesign its geometry such as wrap profile. The design parameters of wrap profile such as base circle radius, wrap height, involute end angle and discharge port have to be well determined to obtain high compressor efficiency. At first, a simulation program has been developed to pred...

Cellular slime moulds (Dictyosteloids) are characterised by at least two different modes of slug migration. Most species, e.g. Dictyostelium mucoroides, produce a stalk continuously during slug migration, while a few species, e.g. Dictyostelium discoideum are characterised by stalk-less slug migration and only produce a stalk upon culmination. Experiments on D. discoideum and theoretical model ...

We analyzed transmission electron micrographs of human lung mast cells by digitized planimetry and point counting to determine the cross-sectional areas of two distinct cytoplasmic organelles: specific granules and lipid bodies. Specific granules have a limiting membrane and often contain one or more cylindrical scroll-like inclusions. By contrast, lipid bodies are on average much larger than g...

Vibration-based condition monitoring and fault diagnosis is an effective approach to maintain the reliable operation of a scroll compressor. Unfortunately, the vibration signal from the scroll compressor always has characteristics of being non-linear and non-stationary, which makes vibration signal analysis and fault feature extraction very difficult. To extract the significant fault features, ...

Abnormal electrical activity from the boundaries of ischemic cardiac tissue is recognized as one of the major causes in generation of ischemia-reperfusion arrhythmias. Here we present theoretical analysis of the waves of electrical activity that can rise on the boundary of cardiac cell network upon its recovery from ischaemia-like conditions. The main factors included in our analysis are macros...

In a world where technology advances, it is important that the human-computer interface follows in the same pace, to maximize the user experience. This means that when the machines become more powerful and the services become more comprehensive, it is important that they still are adapted to the users. In the web browsing world, a concept called infinite-scroll has become popular when trying to...

A new mechanical supercharger-a low compression ratio scroll compressor was introduced in this paper, including the principle, scroll geometry, suction volume, inner compression ratio, etc. Then the advantages of the scroll supercharger were pointed out compared with other superchargers. After some concrete design considerations, a prototype was made and the performance tests showed the results...

We develop a numerical approach based on our recent analytical model of fiber structure in the left ventricle of the human heart. A special curvilinear coordinate system is proposed to analytically include realistic ventricular shape and myofiber directions. With this anatomical model, electrophysiological simulations can be performed on a rectangular coordinate grid. We apply our method to stu...