Surfaces without contact

The concentration of highly active substances (e.g., hormones or cytostatics) on surfaces without contact with the product will not exceed specified limits. 

For a cell, located close to an internal kiln surface without clinker and for a cell with clinker and contacting with a kiln gas the same equation can be written in tbe form ... 

The capacity factor, Zg, defined by equation 7, is derived from a set of assumptions. An additional assumption is specific to the botde centrifuge. Namely, a particle is considered sedimented when it reaches the surface of the cake without contacting the tube wall. 

Not apphcable Not apphcable Not applicable Different types are available for different requirements. Suitable for drying without contacting hot surfaces Not apphcable... 

Optical interferometry can be used to measure surface features without contact. Light reflected from the surface of interest interferes with light from an optically flat reference surface. Deviations in the fnnge pattern produced by the interference are related to differences in surface height. The interferometer can be moved to quantify the deviations. Lateral resolution is determined by the resolution of the magnification optics. If an imaging array is used, three-dimensional (3D) information can be provided. 

The noncontact measurement principle, usually called optical or radiation temperature measurement, is based on detecting electromagnetic radiation emitted from an object. In ventilation applications this method of measurement is used to determine surface temperatures in the infrared region. The advantage is that the measurement can be carried out from a distance, without contact with the surface, which possibly influences the heat balance and the temperatures. The disadvantages are that neither air (or other fluid) temperature nor internal temperature of a material can be measured. Also the temper-... 

A reaction interface is the zone immediately adjoining the surface of contact between reactant and product and within which bond redistributions occur. Prevailing conditions are different from those characteristic of the reactant bulk as demonstrated by the enhanced reactivity, usually attributed to local strain, catalysis by products, etc. Considerable difficulties attend investigation of the mechanisms of interface reactions because this thin zone is interposed between two relatively much larger particles. Accordingly, many proposed reaction models are necessarily based on indirect evidence. Without wishing to appear unnecessarily pessimistic, we consider it appropriate to mention here some of the problems inherent in the provision of detailed mechanisms for solid phase rate processes. These difficulties are not always apparent in interpretations and proposals appearing in the literature. 

The values of the water contact angle of the PFAM film on the slider surface also increased with the concentration of PFAM solutions (Fig. 5 [26]). The water contact angle increased up to 121 ° at 200 ppm from the initial values of 88.4° without the PFAM film, indicating that the PFAM had covered the slider surface well. For N-Hexane, the contact angle was only about 48°, but the contact area was much larger than that on the slider surface without the PFAM film as shown in Fig. 6. 

Here, the structures of interfacial water at a fused quartz surface with and without contact of polyvinyl alcohol (PVA) were investigated by in situ SFG spectroscopy and their role in low friction between PVA and a fused quartz surface is discussed. 

Cutlip and Kenney (44) have observed isothermal limit cycles in the oxidation of CO over 0.5% Pt/Al203 in a gradientless reactor only in the presence of added 1-butene. Without butene there were no oscillations although regions of multiple steady states exist. Dwyer (22) has followed the surface CO infrared adsorption band and found that it was in phase with the gas-phase concentration. Kurtanjek et al. (45) have studied hydrogen oxidation over Ni and have also taken the logical step of following the surface concentration. Contact potential difference was used to follow the oxidation state of the nickel surface. Under some conditions, oscillations were observed on the surface when none were detected in the gas phase. Recently, Sheintuch (46) has made additional studies of CO oxidation over Pt foil. 

Figure 9 An ion mobility spectrometer called the Quantum Sniffer has an inlet with laser or flash-lamp to warm a surface and a vortex sampler (left frame) to pull sample into the analyzer without contact between analyzer and surface (right frame).

An alternative technique is noncontact AFM [18]. Figure 19 illustrates the concept. The tip oscillates above the surface, and the modulation in amplitude, phase, or frequency of the oscillating cantilever in response to force gradients from the sample can be measured to indicate the surface topography. Even without contact, the amplitude, phase, or frequency can be affected by the van der Waals forces of the sample within a nanometer range, which is the theoretical resolution however, this effect can be easily blocked by the fluid contaminant layer, which is substantially thicker than... 

When you fdl a buret with fresh solution, it is a wonderful idea to rinse the buret several times with small portions of the new solution, discarding each wash. It is not necessary to fill the buret with wash solution. Simply tilt the buret to allow all surfaces to contact the wash liquid. This same technique should be used with any vessel (such as a spectrophotometer cuvet or a pipet) that is reused without drying. 

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