Distance-weighted volume

Gas permeability depends on chain mobility and intermolecular distances (free volume). Both properties can be modified by plasticizers. Figure 10.84 shows that by increasing the amount of the plasticizer or increasing the temperature, water permeability is increased. This is a simple illustration of the influence of flee volume on permeability. Replacement of a low molecular weight plasticizer (DOP) by polyolefin flexibilizer decreased oxygen permeability by factor 2.5. " ... 

In 1790, a commission of the French Academy of Science developed a standardized system of weights and measures that defined unitary weights, volumes, and distances on quantities that were deemed unchangeable and that related to each other in some basic manner. This metric system has since developed into the Systeme international d unites (International System of Units abbreviated SI) and is the universal standard recognized and used around the world. 

Assume a continuous release of pressurized, hquefied cyclohexane with a vapor emission rate of 130 g moLs, 3.18 mVs at 25°C (86,644 Ib/h). (See Discharge Rates from Punctured Lines and Vessels in this sec tion for release rates of vapor.) The LFL of cyclohexane is 1.3 percent by vol., and so the maximum distance to the LFL for a wind speed of 1 iti/s (2.2 mi/h) is 260 m (853 ft), from Fig. 26-31. Thus, from Eq. (26-48), Vj 529 m 1817 kg. The volume of fuel from the LFL up to 100 percent at the moment of ignition for a continuous emission is not equal to the total quantity of vapor released that Vr volume stays the same even if the emission lasts for an extended period with the same values of meteorological variables, e.g., wind speed. For instance, in this case 9825 kg (21,661 lb) will havebeen emitted during a 15-min period, which is considerablv more than the 1817 kg (4005 lb) of cyclohexane in the vapor cloud above LFL. (A different approach is required for an instantaneous release, i.e., when a vapor cloud is explosively dispersed.) The equivalent weight of TNT may be estimated by... 

Hydrogen onboard storage systems for vehicles are bulkier, heavier, and costlier than those for liquid fuels or compressed natural gas, but are less bulky and less hca than presently envisaged electric batteries. Even with these constraints, it appears that hydrogen could be stored at acceptable cost, weight, and volume for vehicle applications. This is true because hydrogen can be used so efficiently that relatively little fuel is needed onboard to travel a long distance. 

If a fluid contained in a cylinder expands so that its pressure remains constant (e.g.9 saturated steam in contact with water), the work done is that of raising the piston, of area a, which supports a weight W just sufficient to keep the expansive force indefinitely near equilibrium. If s = distance of outward motion of piston work A = W. s = pa. s = p. as = p v, where Av is the increase of volume. 

An abrasion experiment is carried out by sliding a rubber sample over a given distance and determining the volume loss by some suitable method, usually by determining the difference in weight before and after. It is always assumed that the abraded volume is proportional to the distance covered between measurements, which is reasonable if the sharpness of the track remains constant. Hence, the abraded volume is always referred to unit distance covered. This basic quantity depends on the pressure between the sliding surfaces, the temperamre, speed, and the topography of the track, such as sharpness and coarseness of the asperities. 

The following equation relates the interparticle distance (ID) to the volume fraction of the impact modifier (4)) and the weight-average particle size (dlT) [28] ... 

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