Roughness measurement

For each sample, several measurements were performed at different positions and with different scan sizes. From these data, R and PSD functions were calculated. 

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The true area of contact is clearly much less than the apparent area. The former can be estimated directly from the resistance of two metals in contact. It may also be calculated if the statistical surface profiles are known from roughness measurements. As an example, the true area of contact. A, is about 0.01% of the apparent area in the case of two steel surfaces under a 10-kg load [4a]. 

Guenther K FI, Wierer P G and Bennett J M 1984 Surface roughness measurements of low-scatter mirrors and roughness standards Appl. Opt. 23 3820... 

We may now understand the nature of the change which occurs when an anhydrous salt, say copper sulphate, is shaken with a wet organic solvent, such as benzene, at about 25°. The water will first combine to form the monohydrate in accordance with equation (i), and, provided suflScient anhydrous copper sulphate is employed, the effective concentration of water in the solvent is reduced to a value equivalent to about 1 mm. of ordinary water vapour. The complete removal of water is impossible indeed, the equilibrium vapour pressures of the least hydrated tem may be taken as a rough measure of the relative efficiencies of such drying agents. If the water present is more than sufficient to convert the anhydrous copper sulphate into the monohydrate, then reaction (i) will be followed by reaction (ii), i.e., the trihydrate will be formed the water vapour then remaining will be equivalent to about 6 mm. of ordinary water vapour. Thus the monohydrate is far less effective than the anhydrous compound for the removal of water. 

Testing. Chemical analyses are done on all manufactured abrasives, as well as physical tests such as sieve analyses, specific gravity, impact strength, and loose poured density (a rough measure of particle shape). Special abrasives such as sintered sol—gel aluminas require more sophisticated tests such as electron microscope measurement of a-alumina crystal si2e, and indentation microhardness. 

APHA color (269) is usually one of the specifications of PTMEG, sometimes viscosity is another (270). Melt viscosity at 40°C is often used as a rough measure of the molecular weight distribution within a narrow molecular weight range. Sometimes an empirical molecular weight ratio,... 

Surface Roughness Measurement, Formation by Sputtering, Impact on Depth Profiling... 

Several surface roughness measurement techniques are in common usage. The optimum method will depend upon the type and scale of roughness to be measured for a particular application. 

The standard melt flow index machine is often used for characterising the flow properties of polypropylene and to provide a rough measure of molecular weight. Under the conditions normally employed for polyethylene (2.16 kg load at 190°C) the flow rate is too low for accurate measurement and in practice higher loads, e.g. 10 kg, and/or higher temperatures are used. It has been found that a considerable pressure drop exists in the barrel so that the flow towards the end of a test run is higher than at the beginning. 

Ribosomes, the supramolecular assemblies where protein synthesis occurs, are about 65% RNA of the ribosomal RNA type. Ribosomal RNA (rRNA) molecules fold into characteristic secondary structures as a consequence of intramolecular hydrogen bond interactions (marginal figure). The different species of rRNA are generally referred to according to their sedimentation coefficients (see the Appendix to Chapter 5), which are a rough measure of their relative size (Table 11.2 and Figure 11.25). 

Until one develops a feel for recrystallization, the best procedure for known compounds is to duplicate a selection in the literature. For new compounds, a literature citation of a solvent for an analogous structure is often a good beginning point. To assist in the search, Table A3.4 lists several of the common recrystallizing solvents with useful data. The dielectric constant can be taken to be a rough measure of solvent polarity. 

For freshwater muds, a rough measure of the relative amounts of barite and clay in the solids can be made by using Table 4-45. As both suspended and dissolved solids are retained in the retort for muds containing substantial quantities of salt, corrections are made for the salt [23]. 

This is a rough measure of a limiting viscosity. At temperature above 2.5°C (6.5°F), oil ceases to flow when the vessel in which it has been cooled is held horizontally for 5 seconds. The pour point is a guide to behavior and care should always be taken that the operating temperatures are above the figure specified by the oil manufacturer as the pour point of a given oil. 

Close intramolecular contacts (clashes). A rough measure has been proposed and implemented in the program CONCORD [4,11] - the close contact ratio (CCR). The CCR of a 3D stracture is defined as the ratio of the smallest nonbonded distance to the smallest acceptable value for this distance. Normally, structures with CCR>0.8 are acceptable. Some programs as CORINA [5] or CONCORD [4, 11] have fallback procedures for attempting to relax close contacts in structures with unacceptably low CCR. 

The RMS value is only a rough measure for the similarity of two conformations. It is summarized over all atoms under consideration. That means that a local drastic deviation between two conformations can be hidden in an overall good fit. Reversely, a deviation in one part of the molecule can hide a perfect fit of another part. However, the RMS is very useful for obtaining a quick, robust measure of conformational similarity. A few recommendations can help to a better understanding ... 

The above values can only represent a rough measure of basicity, since it has been found23,43 that cyclopropenones do not behave as Hammett bases. A refined treatment minimizing the NMR effects extraneous to the protonation of interest gave H0 values of —5.0 for methyl cyclopropenone and —1.5 for dimethyl cyclopropenone23. ... 

A rough measure for the overlap concentration 4>ov is that volume fraction of polymer at which close-packed spheres with radius rg just touch. Then 4> =0.74 rl /(4Trr /3). Taking r — A((J> - 0) ... 

One dimensional conjugated carbon polymers can occur in many configurations as depicted in Figure 2 where also we included some chains with nitrogen and sulfur for later reference. Also included there are inorganic one dimensional semiconductors, like SbSI and SbSBr for later comparison. Besides the depicted one-dimensional system others like TCNQ- and KCP-salts could be included here as well but rough measurements of their nonlinear coefficients gave deceptively small values which combined with their ill-characterisation make them poor candidates for nonlinear optical devices. 

Among the Ti-SBA-15 samples, the activity decreased in the order, sample 1 > sample 2 > sample 3. The intensity of the broad band in the 200-350 nm DRUV spectra of these samples also follows the same order (Fig. 36) and is a rough measure of the dispersion of Ti in the sample. The higher catalytic activity of Ti-MMM was ascribed to its greater surface Ti concentration. 

Figure 4.21 Atomic force microscopy images showing the morphology of coloured Si02-PMM A hybrid coatings with molar ratio formulation of 1 0.5 1.0 TEOS-TMSPM MMA, with different concentrations and types of colour (a) no colour (b) 0.17 wt% of blue colour (c) 0.83 wt% of green colour. The values of the r.m.s. average roughness measured for the three films was 0.47, 0.65 and 0.45 nm, respectively. (Reproduced from ref. 21, with permission.)...

Surface roughness was measured according to ANSI standard 1346.1-(1978) using a Tencor Instruments Alpha-Step 200 stylus profilometer located at the National Nanofabrication Facility of Cornell. Five surface roughness measurements were made for each sample and their average values recorded. Details of the experimental apparatus set-up and its operation are given elsewhere (Dems, B. C. et. al. Inti. Polvm. Proc.. in press.). 

Surface Roughness measured with Tencor Instruments Alpha-Step 200 stylus profilometer per ANSI Standard 1346.1-(1978)... 

This concordance between the nitrogen and 170 shifts arises because of the importance of the AE term, a rough measure of which is given by UV spectra and CD maxima. Some comparisons are given in Table 17. 

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