Suction pull

Figure 15.7 Starling principle a summary of forces determining the bulk flow of fluid across the wall of a capillary. Hydrostatic forces include capillary pressure (Pc) and interstitial fluid pressure (PJ. Capillary pressure pushes fluid out of the capillary. Interstitial fluid pressure is negative and acts as a suction pulling fluid out of the capillary. Osmotic forces include plasma colloid osmotic pressure (np) and interstitial fluid colloid osmotic pressure (n,). These forces are caused by proteins that pull fluid toward them. The sum of these four forces results in net filtration of fluid at the arteriolar end of the capillary (where Pc is high) and net reabsorption of fluid at the venular end of the capillary (where Pc is low).

Using gentle suction, pull the cell into a glass electrode having a tip diameter roughly equivalent to that of the cell. Take care to minimize the uptake of buffer solution bathing the cells. 

Thin plastic sheets may be formed into trays by vacuum forming (Figure 16-15). This process is different than injection molding. The plastic sheet is laid across a form and then heated to a softened state, but not melted. Vacuum suction pulls the softened plastic sheet down into the mold. 

Spannkraft, Zugkraf) Brack (suction/pull) Sog, Zug (Wasserleitung) tensioning Strecken, Spannen,... 

The basic design is that of the Ostwald viscometer a U-tube with two reservoir bulbs separated by a capillary, as shown in Figure 24a. The Hquid is added to the viscometer, pulled into the upper reservoir by suction, and then allowed to drain by gravity back into the lower reservoir. The time that it takes for the Hquid to pass between two etched marks, one above and one below the upper reservoir, is a measure of the viscosity. In U-tube viscometers, the effective pressure head and therefore the flow time depend on the volume of Hquid in the instmment. Hence, the conditions must be the same for each measurement. 

BEOs are most often used for point sources or small line or surface sources. See Chapter 7 for descriptions of sources. BEOs are sometimes used for lines or surfaces when the source is moving along the line or on the surface. This naturally demands the exhaust to move with (or be moved with) the source movements (e.g., during painting or seam welding). They have also been used for side suction from baths and tanks-- and these exhausts are usually called rim exhausts see Rim Exhausts. However, for these sources push-pull systems (Section 10.4.3) are often more efficient. Side hoods can also be used, e.g., when molten metal is poured however, in these cases an enclosed exhaust is more efficient. 

Figure 10.87 shows the fundamental operation of the push-pull flow. The suction hood should simultaneously exhaust the pushed air (contaminated supply... 

If a plant has been shut down long enough for all pressures to equalize and is then restarted, the suction pressure will pull down below normal until the liquid refrigerant has begun to circulate. Under such circumstances the low-pressure switch may operate. This is a normal occurrence, but may require the addition of a delay timer to prevent frequent starting of the compressor motor. 

Filter the homogenate with suction through a fast flow-rate filter-paper in a Buchner funnel until more than 200 mL of filtrate is obtained. Apply only gentle suction to avoid the loss of acetone by evaporation therefore, do not allow the filter cake to pull dry. The filtration should take not more than 1 min. 

The term capillary action describes the upward movement of a fluid as a result of surface tension through pore spaces. The fluid can rise until the lifting forces are balanced by gravitational pull (see Figure 3.28). The rise of fluid in a small tube above the water table surface, as previously discussed in Chapter 3, can be described using Equation 3.13. Lifting of fluids above the water table is a true negative pressure compared with atmospheric pressure (also described as soil suction). In soil situa-... 

We use 100 pi glass capillary tubes (VWR international 53432-921) pulled by a horizontal micropipette puller (Sutter Instrument Co. Model P-97) for suctioning of adipose tissue. Suction strength is controlled by tip size which is typically 10-20 pm. 

Two suction cups at the bottom of the mine secured it to target when pressed. Ignition was made by two Friction Pull Igniters which were lashed to the bottom of pole (p 209,... 

In use the sample is pulled through the valve by a pump, squeeze bulb, or even a syringe used in the suction mode. If the gas is under pressure it is allowed to flow through the valve. Sufficient volume of gas is needed to insure that the "loop" or valve volume contains the sample to be analyzed. For a 1-cm3 sample loop volume generally 10 cm3 of gas is a sufficient flush. The valve is then rotated to the inject position. This action places whatever is in the valve loop into the carrier gas flow where it is carried directly to the column for separation. The biggest... 

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