Pressure-induced Disturbance

Roof (Back), Floor, and Ribs As an orebody is extracted, the natural ground condition surrounding it is disturbed, and physical hazards are created. The pressures induced by mining on the ribs (walls), corners, and cores of pillars depends on the following factors ... 

Proximal tubule cells are exquisitely sensitive to vasculat disturbances and acute tubular necrosis (ATN) can occur naturally in areas of poor perfusion resulting from falling blood pressure, or vasospasm of renal vessels or arterioles. In other words hypoxia associated with partial ischaemia can cause severe damage. It is not then surprising that anoxia associated with iatrogenic, surgically induced total ischaemia produces irreversible damage within a short time unless steps are taken to prevent it. 

The vibration induced by the fluid flowing over the tube bundle is caused principally by vortex shedding and turbulent buffeting. As fluid flows over a tube vortices are shed from the down-stream side which cause disturbances in the flow pattern and pressure distribution round the tube. Turbulent buffeting of tubes occurs at high flow-rates due to the intense turbulence at high Reynolds numbers. 

Those experiencing intoxication with Henbane feel a pressure in the head, a sensation as if someone were closing the eyelids by force sight becomes unclear, objects are distorted in shape, and the most unusual visual hallucinations are induced. Gustatory and olfactory hallucinations frequently accompany the intoxication. Eventually sleep, disturbed by dreams and hallucinations, ends the inebriation. 

In rats, 40% propene caused light anesthesia with no other toxic symptoms within 6 hours 55% propene for 3-6 minutes or 70% propene for 1-3 minutes produced deep anesthesia with no additional central nervous system disturbances. Animal experiments with cats have shown no toxic signs when anesthesia was induced at concentrations of 20-31% however, 70% propene resulted in a drop in blood pressure and an increased pulse rate, and an unusual ventricular ectopic beat occurred at concentrations ranging from 50% to 80%. 

Doses above 250 mg provide no further blood pressure reduction, but are more likely to induce metabolic disturbance (hypokalemia, hyperuricemia, etc.)... 

Narcosis due lo CO is characterized by mental disturbances which may range from confusion, mania, or drowsiness to deep coma, headache, sweating, muscle twitching, increased intracranial pressure, pounding pulse, low blood pressure, hypothermia, and sometimes papilloedcina. The basic mechanisms by which carbon dioxide induces narcosis is probably through interference with the intracellular enzyme systems, which are all sensitive to pll changes. 

A qualitative evidence of the above are the data reported in [52]. It has been established that there is a correlation between the calculated rate of internal diffusion foam collapse and the experimentally determined rate. To obtain a stable foam from poor surfactants (alcohols, acids, etc.) under these conditions is hardly possible because of either insufficient dynamic elasticity of foam films or the lack of equilibrium elasticity (for films from insoluble surfactants). Furthermore, the n barrier for films from acid or alcohol solutions is low and the typical capillary pressures for a real foam are sufficient to induce disturbance of the film equilibrium and, respectively, foam collapse. 

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