Pressure and buoyancy

Few studies aimed at understanding the effects of pressure on metabolism in fish have been performed in the Black Sea or Sea of Azov because no distinct stratification was found in the distribution of water animals there. The Sea of Azov is saucer-like, its maximum depth being only 15 m, and in the Black Sea the oxygenated water layer extends only to 150 m depth. However, Emeretli (1996) has shown that activity of lactate dehydrogenase in the liver increases 2-10 times in scorpion fish and annular bream placed in a barorespirometer (designed by A. Stolbov) and sunk to a depth of 300 m. This response seems to be peculiar to shallow-water species (Hochachka and Somero, 1984). 

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Rotameter A rotameter consists of a vertical tube with a tapered bore in which a float changes position with the flow rate through the tube. For a given flow rate the float remains stationary since the vertical forces of differential pressure, gravity, viscosity, and buoyancy are balanced. The float position is the output of the meter and can be made essentially linear with flow rate by makiug the tube areavaiy hn-early with the vertical distance. 

Sub-ground pits may be required for access, service distribution or process requirements. Depending on pit dimensions and water table levels, problems that may have to be considered at the design stage include heave due to relief of overburden, buoyancy from water pressure and waterproofing. 

The hose couplings, buoyancy control (air pressure) and method of initiation (by Prima-cord) were the same as for the NOL Streamer in Use at that time. The only apparent weakness of the duPont streamer was that the pellets were broken to some extent by handling and countermining. The disadvantage of foe pellet load was largely eliminated by the EL development of a blend of flaked and grained TNT for use in the NOL canvas sock... 

Fig. 5.1 Experimental data on hydrogenation of Cm at 120 bar hydrogen pressure and -673 K. The initial kink of the weight curve at about 1,000 min occurs during an increase of hydrogen pressure and simultaneous increase of temperature which influences the curve due to buoyancy effects. XRD patterns recorded from the samples 1,2,3 and compared to the pattern from original C. Samples 1 and 2 were obtained in one experiment sample 3 was obtained in a separate experiment (Talyzin et al. 2004a)...

The forces acting on a droplet attached to the pore opening can be conveniently subdivided into perpendicular and parallel direction with respect to the membrane surface. Considering the former case, the Young-Laplace FYl [39] (named also static pressure force), the dynamic lift FDL and buoyancy FBg forces [26] are generally taken into account. They are defined as ... 

In these equations, p is the pressure relative to the local ambient pressure and. as before, is the angle between the direction of the forced velocity and the direction of the buoyancy forces as defined in Fig. 9.3. The x-axis is in the direction of the undisturbed forced flow. 

Two principal PS foams that are fabricated are extruded foam and expanded for molded foams. PS foams are light, closed-cell foams with low thermal conductivities and excellent water resistance. They provide for low-temperature insulation and buoyancy media. The extruded PS foam is fabricated as billets and boards. They are made by extruding molten PS containing a blowing agent, under elevated temperature and pressure, into the atmosphere, where the mass expands. Billets and boards can be used directly or can be cut into many different forms.254... 

Non-adsorbable gas introduced at room temperature up to c. atmospheric pressure and apparent mass change recorded (to obtain buoyancy correction). 

At the dry adiabatic lapse rate (9.8°C decrease in temperature per kilometer increase in altitude), a rising parcel of dry air that does not exchange heat with the environment will cool by expansion due to the decrease in air pressure and will achieve the same temperature as the surrounding air—a case of neutral stability. That is, air movement is then neither favored nor retarded by buoyancy. Observed lapse rates are usually -5 to -7°C km-1, reflecting heat exchange with the environment and the possibility of heat release due to water condensation at higher altitudes. 

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