Linear velocity measurement

As the pelvis rotates and tilts, a torsional efiect develops at the symphysis pubis. This is created because every part of the pelvis is moving at a different linear velocity. Measuring the displacement of rotation and tilt of the lateral edge of the r t innominate from the fixed left hip will show that the angular velocity is constant from eveiy part of the left and right Innominates, but the linear velocity, and therefore the distance traveled, increases from left to right. Thus, the... 

The average linear velocity u of the mobile phase in terms of the column length L and the average linear velocity of eluent (which is measured by the transit time of a nonretained solute) is... 

A solute s capacity factor can be determined from a chromatogram by measuring the column s void time, f, and the solute s retention time, (see Figure 12.7). The mobile phase s average linear velocity, m, is equal to the length of the column, L, divided by the time required to elute a nonretained solute. 

Signal-to-noise ratio measured at conditions wavelength (A) = 800 nm, carrier frequency (/) = 1 MHz, linear velocity of the disk (t ) = 5 m/s, bandwidth (BW) = 30 kHz, unless otherwise noted. 

Centripetal Acceleration. Centripetal acceleration, /r or CO r, where is the tangential linear velocity (m/s), rthe radius (m), and CO the angular velocity (rad/s), is, like any other linear acceleration, measured in SI units m/s. Centripetal force, equal to mass times centripetal acceleration, is, like any force in SI, measured in newtons. 

The measurement of the linear velocity as a function of shaft RPM can be done at room temperature and pressure in air. It is best to do this on the catalyst already charged for the test. Since u is proportional to the square of the head generated, the relationship will hold for any fluid at any MW, T, and P if the u is expressed at the operating conditions. The measurement can be done with the flow measuring attachment and flow meter as shown in Figure 3.5.1. 

Remember diameters of the measuring tube and basket are different. Correct the linear velocity in the basket by reading the area differences. 

The flow that is shown in these figures is the instrument flow measured as m/s in the measuring tube. Multiplied with the flow cross-section of 5.59 cm, this gives the volumetric flow in the 2.67-cm diameter flow tube. Using a different catalyst basket or measuring tube will change this ratio. The volumetric flow is the same in the basket. Because the small basket has a 3.15 cm diameter and 7.79 cm cross-section, the linear velocity will be 5.59/7.79 = 0.72 fraction of that in the tube. 

The silica dispersion showed the smallest retention volume. It should be noted, however, that the authors reported that the silica dispersion required sonicating for 5 hours before the silica was sufficiently dispersed to be used as "pseudo-solute". The retention volume of the silica dispersion gave the value of the kinetic dead volume, /.e., the volume of the moving portion of the mobile phase. It is clear that the difference between the retention volume of sodium nitroprusside and that of the silica dispersion is very small, and so the sodium nitroprusside can be used to measure the kinetic dead volume of a packed column. From such data, the mean kinetic linear velocity and the kinetic capacity ratio can be calculated for use with the Van Deemter equation [12] or the Golay equation [13]. 

It is seen that the value of (H) is completely dependent on the diffusivity of the solute in the mobile phase, the column radius and the linear velocity of the mobile phase. The simple uncoated open tube can clearly be used to determine the diffusivity of any solute in any given solvent (the mobile phase). This technique for measuring diffusivities will be discussed in a later chapter. 

H) was determined for each solute, in each solvent mixture, for 10 different linear velocities ranging from 0.02 cm/sec. to 0.6 cm/sec. Three measurements were taken at each velocity, which produced a minimum of 180 values of (H) for each solute. Each data set was then fitted to each dispersion equation and the respective constants... 

Now, at high linear velocities, the longitudinal diffusion term will become insignificant and, equally important, the resistance to mass transfer term that incorporates the inverse function of diffusivity will become large, thus improving the precision of measurement. 

The airflow pattern in rooms ventilated by linear attached jets with L/H ratio greater than that for effectively ventilated rooms was studied by Schwenke and Muller. The results of their air velocity measurements ami visualization studies indicate that there are secondary vortexes formed downstream in the room and in the room corners. The number of downstream vortexes and their size depend upon the room length (Fig. 736b). Mas,s transfer between the primary vortex and the secondary vortex depends upon the difference in characteristic air velocities in the corresponding flows (/, and Ui and can be described using the Stanton number, St . ... 

An important parameter when considering GC resolution of the sample components is the carrier gas linear velocity (flow rate, F), which can be determined by injecting 5-50 /A of argon or butane and measuring the time from injection to detection by the mass spectrometer. An optimum linear velocity using helium as a carrier gas is approximately 30 cm/sec and... 

Visual proof of linear kinetics, making obvious the occurrence of undesirable conditions such as substrate depletion or lag phase non-linearity. Visual display of changes in the reaction rate. Maximum accuracy as the measurement can be made in the region of maximum linear velocity. 

If the inhibition is found to be rapidly reversible, we must next determine if the approach to equilibrium for the enzyme-inhibitor complex is also rapid. As described in Chapter 4, some inhibitors bind slowly to their target enzymes, on a time scale that is long in comparision to the time scale of the reaction velocity measurement. The effect of such slow binding inhibition is to convert the linear progress curve seen in the absence of inhibitor to a curvilinear function (Figure 5.10). When nonlinear progress curves are observed in the presence of inhibitor, the analysis of... 

This section describes a new waveform design for automotive applications based on CW transmit signals which lead to an extremely short measurement time. The basic idea is a combination of linear frequency modulation (LFM) and FSK CW waveforms in an intertwined technique. Unambiguous range and velocity measurement with high resolution and accuracy can be required in this case even in multi-target situations. After introductions to FSK and LFM waveform design techniques in sections 2.1 and 2.2 the combined and intertwined waveform is described in detail in section 2.3. 

The analysis can be made in situ using an optical, thermal, electrical or other method. The average time, during which the reaction proceeds before an element of volume and reaches a distance d along the reaction tube, is d/v, where v is the linear velocity. From the measurements made at various... 

The value of (H) for each solute was determined in each solvent mixture over 10 different linear velocities that covered the normal practical range of velocities used in LC. Measurements at each velocity were taken in triplicate which resulted in a minimum of 180 values of (H) being taken for each solute. Each data set, from each solvent mixture, was fitted to each dispersion equation and the values for the respective constants (A), (B), (C), etc. calculated, together with the index of determination for each fitting, it ia seen that the data was sufficient in both quantity, and quality to be able to dentify the most appropriate dispersion equation with some confidence. The results obtained are shown in table 2. 

Because the approach velocity v, that is, the gas velocity prior to entering the powder bed is experimentally simple to measure, it is desirable to state equation (7.21) in terms of v rather than Dp. In order to make this conversion consider Fig. 7.2. The unshaded area represents gas contained between a piston and the surface of the powder bed. If the porosity p of the bed is 0.5, then in order to contain an equal volume of gas, the powder bed must be twice as long as the distance the piston can move. Clearly then, if the piston is displaced downward at a uniform rate the linear velocity through the bed must be twice the approach velocity, or... 

Figure 2.2—Optimum linear velocity and viscosity of carrier gas. The optimal mean linear velocities of the various carrier gases are dependent on the diameter of the column. The use of hydrogen as a carrier gas allows a faster separation than the use of helium while giving some flexibility in terms of the flow rate (which can be calculated or measured). This is why the temperature program mode is used. The significant increase in viscosity with temperature can be seen for gases. In addition, the sensitivity of detection depends on the type of carrier gas used.

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