Coil diameter

In contrast to the planar wave solution, the penetration depth in case of a coil can be described —besides the dependence on co and a— as a function of the depth z and the coil diameter R ... 

We improve the penetration of eddy currents by increasing the probe diameter. The useful diameter is generally equal to the coil diameter to which we add four times the standard thickness 8. 

In order to adequately describe the size of a heater, the heat duty, the size of the fire tubes, the coil diameters and wall thicknesses, and the cor lengths must be specified. To determine the heat duty required, the maximum amounts of gas, water, and oil or condensate expected in the heater and the pressures and temperatures of the heater inlet and outlet must be known. Since the purpose of the heater is to prevent hydrates from forming downstream of the heater, the outlet temperature will depend on the hydrate formation temperature of the gas. The coil size of a heater depeiuLs on the volume of fluid flowing through the coil and the required heat duty. 

Volume 1, Chapter 9 explains the criteria for choosing a diameter and wall thickness of pipe. This procedure can be applied to choosing a coil diameter in an indirect fired heater. Erosional flow criteria will almost always govern in choosing the diameter. Sometimes it is necessary to check for pressure drop in the coil. Typically, pressure drop will not be important since the whole purpose of the line heater is to allow a large pressure drop that must be taken. The allowable erosional velocity is ffiven bv ... 

After the minimum inside diameter and the required wall thickness, a coil diameter and wall thickness may be selected. Very often, the coil length downstream of the choke (L2) is of a different diameter and wall thickness than the length upstream of the choke (L,). 

A related but somewhat more recent work by Oldshue presents heat transfer to and from helical coils in a baffled tank, using standard baffling of T/12 located either inside the coil diameter or outside ... 

The whole NMR imaging sensor system usually consists of a magnet, a shim system mounted inside the room-temperature bore of the magnet, a gradient system mounted inside the shim system and the rf coil mounted inside the gradient system. In the case of a saddle coil or a birdcage resonator, open access can be realized from the bottom to the top of the entire system with the coil diameter. 

Calculate the frictional pressure gradient ApyL for a liquid in steady state turbulent flow in a coil of inside tube diameter d,= 0.Q2 m and coil diameter Dc = 2 m if the liquid density... 

Providing that hid remains constant, the RF coil sensitivity is inversely proportional to the coil diameter for solenoidal coils of diameter greater than about 100 p,m. It can be shown theoretically and has been demonstrated experimentally that the sensitivity of a solenoidal coil is about three times that of a saddle coil of the same size [3], In order to translate the coil sensitivity into measurement of SIN defined by Equation 7.6, we also have to consider the noise characteristics of NMR microcoils. For coils of diameter less than 3 mm, the major noise source is from the resistance of the coil itself, and the noise from even lossy biological samples can be neglected [10]. 

A proper choice of the parameters for the extension springs can provide the desired stiffness, endurance, and to minimize the dimension of the instrument. A simple theory of the deflection and maximum stress of springs is presented in Appendix F. The relation between the axial load P and the deflection F of a spring with coil diameter D, number of coils n, and wire diameter d is ... 

The magnetic field was obtained by the use of Helmholz coils or an iron core magnetic. The former had mean coil diameters of 38 cm spaced 19 cm apart to maximize the uniformity of the field near the gage base. This gave a usable working gap of about 4 cm. The latter had square pole faces of 10.2 cm on a side spaced... 

New nomenclature da is outside tube diameter of coil, Dc is coil diameter, tiby is number of vertical baffle-type coils, Sc is coil spacing, W is impeller blade width, and Zt is height of coil from tank bottom. 

Obviously, the enthalpy gain can compensate for some unfavorable change in entropy. At a suitable value of adsorption energy, flexible macromolecules may reptate into narrow pores. Polystyrene of molar mass 173,000 g/mol and coil diameter 30 nm is reported to be capable of entering pores of silica gel with 10 nm average pore diameter8). This penetration will certainly be a slow process. It often has been observed that the amount of polymer adsorbed by porous adsorbents slowly increases over a protracted period of time. This may be due to similar effects. 

Figure 7.3.1.2 S/N per unit sample volume as a function of coil diameter for solenoidal coils. The 1 Id and (1 /d )1 2 asymptotes do not account for the resistance of the lead and thus are not followed exactly by either theoretical or experimental data points. Adapted by permission of Academic Press, from Peck, T. L., Magin, R. L. and Lauterbur, P. C., J. Magn. Reson., B., 1995, 108, 114...

Coil loop diameter is 0.8 of vessel diameter % Loop spacing is one coil diameter % Given conversion and parameter values, program calculates % (1) Steady-state design (volume,jacket area, coolant flow and temp)... 

Polymer chains are hardly ever met in a totally stretched condition, but are, because of their mobility and flexibility, present as coils. The coil can show all kinds of shape, as dictated by chance as a first approximation we may assume a spherical shape. The diameter of this sphere is hard to define the density in the coil decreases from the centre to the outer boundary. The easiest criterion is the end-to-end distance, r0 this is a strongly fluctuating statistical quantity, of which we must, therefore, try to define some kind of average. This average has some relation with the effective coil diameter. 

Fig. 14. Dimensionless hydrodynamic thickness vs. chain length, on a log-log scale as calculated from the SF model (Cohen Stuart et al., 1984c) for y, = 1, y = 0.45,

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