Displacement, volume determined

Example 6.16 The Flow Rate of a Gear Pump Ideally the displaced volume determines the flow rate of a gear pump, and it is independent of rheological properties. If the volume of... 

Tlic density (p) of a substance is tlic ratio of its mass to its volume and may be expressed in units of pounds per cubic foot (Ib/ft ) or kilograms per cubic meter (kg/nv ). For solids, density can be determined easily by placing a known mass of the substance in a liquid and measuring tlie displaced volume. The density of a liquid can be measured by weighing a known volume of the liquid in a gradmitcd cylinder. For gases, tlie ideal gas law (to be discussed in Section 4.6) can be used to calculate tlie density from tlie temperature, pressure, and molecular weight of tlie gas. 

Nguyen et al. [205] designed a volume displacement technique that was used to measure the capillary pressures for both hydrophobic and hydrophilic materials. One requirement for this method is that the sample material must have enough pore volume to be able to measure the respective displaced volume. Basically, while the sample is filled wifh water and then drained, the volume of water displaced is recorded. In order for the water to be drained from fhe material, it is vital to keep the liquid pressure higher than the gas pressure (i.e., pressure difference is key). Once the sample is saturated, the liquid pressure can be reduced slightly in order for the water to drain. From these tests, plots of capillary pressure versus water saturation corresponding to both imbibitions and drainages can be determined. A similar method was presented by Koido, Furusawa, and Moriyama [206], except they studied only the liquid water imbibition with different diffusion layers. 

If the compression is to be maintained in this volume, increasingly large displacements of water near the source are necessary, despite the weakening of the initial pressure at the front by spherical divergence. The pressure in the gas sphere, however, decreases as the volume determined by the spherical boundary increases, and the strength of this source must decrease. Outward accelerations of the water near the boundary will thus decrease, but as long as there is a pressure excess over hydrostatic, outward flow continues. 

Micromeretics GeoPyc 1360 measures envelope density this includes the volume of pores and surface crevices. When absolute density is inputted, specific pore volume and percent porosity are determined. The instrument uses a flowing dry medium, DryFlo , to surround the powder and generate the displacement volume. 

In-situ density may also be determined from irregularly shaped field samples, by measuring the total volume by water displacement, then determining the specific gravity and volume of solids by standard test methods. To use this process, the grout in the soil voids must be eliminated. For the acrylics this is readily done by heating to the point where the gel vaporizes. 

How can mass and volume data for an unknown sample be used to identify the unknown A student collected several samples from a stream bed that looked like gold. She measured the mass of each sample and used water displacement to determine each sample s volume. Her data are given in the table. 

FIGURE 3.93 Determination of open cell content of rigid cellular plastics. Open cell content (approx.) = 100 (V— Vp/V, where displacement volume of specimen, cm and V, geometric volume of specimen, cm. Standard test... 

For tins problem, you need to determine whether air is present by measuring various densities and determining if there are differences. First, the unopened can must be weighed and its volume determined (by displacement if possible). Next, die soda must have its density determined separately, perhaps by measuring the mass of a volumetric container such as a graduated cylinder when empty and when filled with a known volume of soda. There s some chance that the density of the aluminum can be ignored in this problem, but if necessary, it could be measured. If the density measured for the whole system varies fi om that measured for the soda alone, the most logical source for the difiference would be gas in the head space. ... 

Stationary phase retention cannot be measured directly and, hence, its determination relies upon the measurement of displaced volumes of stationary phase (Ve) from a CCC system and a number of assumptions. The basic equations for the measurement of retention are ... 

Here x and y are dimensions of the jump unit of flow and V is the displacement volume of the unit of flow. The values of x, y, and V for real systems are unknown. However, the dimensionality of xy/ V is a unit of reciprocal length which looks very similar to the shift factor used by Schonhorn et aV Although experiments to test the validity of the Cherry and Holmes expression will be difficult, the apparent agreement of their derivation with the results of Schonhorn et al is very satisfying in the conceptual sense. Cherry and El Muddarris have attempted to determine the effect of wetting kinetics on the strength of adhesive bonds, but the results were not conclusive. " ... 

IV.5.2.2.2 Density determinati n by the Archimedes principle The density determination of a polymer may be performed by a simple experiment based on the Archimedes principle. A polymer sample has been immersed in a liquid with known density. The upward pressure which is generated by immersion of the polymer sample into the liquid is equal to the weight of the displaced volume and this can be measured by a balance. A schematic drawing is given in figure IV - 40. 

The total polymer retention at the highest injected concentration, 6OO ppm, was determined by material balance of injected and produced fluids. Inaccessible displaceable volume was calculated by Eq. 1 as the difference between displaceable volume and the volume of polymer produced after the core had been changed from polymer to brine injection. 

The accuracy of sonographic volumetry was estimated by preoperative or post mortem ultrasonic scanning compared with the volume at strumectomy or autopsy by water displacement. Sonographically determined thyroid volume is reproducible with a maximum deviation of 10 % (6, 15). Ultrasonography becomes inaccurate in large nodular goiters, since the formula applied for calculation is based on an ellipsoid model. In these patients, a rather precise... 

The porosity of the samples was determined using QuantaChrome Stereopycnometer with Nitrogen gas medium using the gas pycnometer test method ASTM D6226-98. This method measures the accessible cellular volume of a material. The remaining volume is that occupied by closed cells, cell walls, and unfoamed sohd polymer. A gas pycnometer is designed to measure the volume of sohd objects. This is accomplished by employing the Archimedes principle of fluid displacement to determine the volume. The displaced fluid is a gas,... 

---