Characteristic thickness

Brauer (B14), 1956 Extensive experimental study of film flow outside tube 4.3X130 cm. films of water, water + surfactant, aqueous diethylene glycol solutions, kinematic viscosity 0.9-12.7 cs. Nr = 20-1800. Data on film thicknesses, waves, maximum and minimum thicknesses, characteristic Reynolds numbers of flow, onset of rippling and turbulence, wall shear stress, etc. 

Stable, very thick films, approximately 100 nm in thickness, characteristic of the single-component soya bean lecithin film ... 

A novel UV detector has been reported for preparative scale HPLC in which the solvent is allowed to flow over a supporting plate where it assumes the thickness characteristic of the flowing liquid film. The UV radiation falls on the film a little below the delivery tube from the column. The detector has been used for concentrations from lmg to 30 g and for flow rates from 1ml min-1 to 400 ml min-1. 

Solanum tuberosum is a species of the Solanaceae family. The pereimial, cross-pollinated plant reaches a height of about 80 cm and develops white or purple flowers and a thick characteristic tuber. The tuber has a starch content of about 15% (fresh matter) consisting of 79% amylopectin and 21% amylose [10]. 

Most chromate conversion coatings are amorphous gel-like precipitates, so they are excellent in continuity. The service life is dependent on thickness, characteristics of the base metal, coating conditions—particularly dry heat—and the environmental conditions under which the chromated products are used. 

Iv) Comparison of the non-dimensional speed-load versus non-dimensional minimum film thickness characteristic obtained by the authors using the half-Sommerfeld boundary condition with the analytical prediction of Snidle and Archard has been undertaken. One influential factor in the comparison is the difference of the areas of pressure generation which leads to an underestimation of load capacity (for a given film thickness) by the Snidle and Archard formula for the present situation. This is particularly true at high values of the radius ratio. The other factor relates to the non-zero pressure boundary condition adopted by Snidle and Archard. 

This chapter starts with a brief overview about Mg-based BMGs and describes principal strategies and challenges for the achievement of maximum amorphous sample thickness. Characteristic thermal data and mechanical properties are summarized. Some fundamental considerations about the effect of microstructural refinements up to the adjustment of single-phase amorphous states on the corrosion reactivity of Mg-based alloys are made. 

Typical correlation between the magnetic characteristic and the body force measured on the head of 85 mm long M24 Friedberg 10.9 bolts where the thickness off the plates screwed together is more than 40mm. 

Several prototypes have been built and give the following characteristics (for 2 mm thick Csl screen) ... 

General hydrodynamic theory for liquid penetrant testing (PT) has been worked out in [1], Basic principles of the theory were described in details in [2,3], This theory enables, for example, to calculate the minimum crack s width that can be detected by prescribed product family (penetrant, excess penetrant remover and developer), when dry powder is used as the developer. One needs for that such characteristics as surface tension of penetrant a and some characteristics of developer s layer, thickness h, effective radius of pores and porosity TI. One more characteristic is the residual depth of defect s filling with penetrant before the application of a developer. The methods for experimental determination of these characteristics were worked out in [4]. 

The thickness of dry developer s layer is substantially smaller in a zone imbibed by a penetrant due to the process of particles sedimentation. Reduced thickness h of imbibed zone can be 80% smaller than the thickness h of dry one. It must be taken into account in the calculations of PT characteristics in the frame of the theory [1-3]. 

For interpretation of measuring results, calibration characteristics obtained on the samples in advance is used in the above instruments. However, if number of impediment factors increases, the interpretation of the signals detected becomes more complicated in many times. This fact causes the position that the object thickness T and crack length I are not taken into consideration in the above-mentioned instruments. It is considered that measuring error in this case is not significant. 

Fig. 3 Calibration characteristics of electropotential transformer in case of object thickness (T) varying.

Roll marks and the edge of the tube sheet provides distinct reference points as scan characteristics and tube thickness may change dramatically at these points. 

The characteristic isotherm concept was elaborated by de Boer and coworkers [90]. By accepting a reference from a BET fit to a standard system and assuming a density for the adsorbed film, one may convert n/rim to film thickness t. The characteristic isotherm for a given adsorbate may then be plotted as t versus P/P. For any new system, one reads t from the standard r-curve and n from the new isotherm, for various P/P values. De Boer and co-work-ers t values are given in Table XVII-4. A plot of t versus n should be linear if the experimental isotherm has the same shape as the reference characteristic isotherm, and the slope gives E ... 

The existence of a characteristic isotherm (or of a r-plot) gives a very important piece of information about the adsorption potential, at least for polar solids for which the observation holds. The direct implication is that film thickness f, or alternatively n/n is determined by P/I independent of the nature of the adsorbent. We can thus write... 

Let H and L be two characteristic lengths associated with the channel height and the lateral dimensions of the flow domain, respectively. To obtain a uniformly valid approximation for the flow equations, in the limit of small channel thickness, the ratio of characteristic height to lateral dimensions is defined as e = (H/L) 0. Coordinate scale factors h, as well as dynamic variables are represented by a power series in e. It is expected that the scale factor h-, in the direction normal to the layer, is 0(e) while hi and /12, are 0(L). It is also anticipated that the leading terms in the expansion of h, are independent of the coordinate x. Similai ly, the physical velocity components, vi and V2, ai e 0(11), whei e U is a characteristic layer wise velocity, while V3, the component perpendicular to the layer, is 0(eU). Therefore we have... 

Another important characteristic of a gas chromatographic column is the thickness of the stationary phase. As shown in equation 12.25, separation efficiency improves with thinner films. The most common film thickness is 0.25 pm. Thicker films are used for highly volatile solutes, such as gases, because they have a greater capacity for retaining such solutes. Thinner films are used when separating solutes of low volatility, such as steroids. 

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