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Non-contact terms

The second mode of operation is the non-contact mode, in which the distance between tip and sample is much larger, between 2 and 30 nm. In this case one describes the forces in terms of the macroscopic interaction between bodies. Magnetic force microscopy, in which the magnetic domain structure of a solid can be imaged, is an example of the non-contact mode operation. [Pg.164]

An instrument for measuring temperatures, in the rubber industry the term is usually applied to an instrument for determining the surface temperature of mill and calender rolls, moulds, etc. The instrument is usually based on thermocouples or, where higher accuracy is required, platinum resistance thermometers. Infrared (IR) techniques are now used which have the advantage of non contact but require careful calibration for the emissivity of the surface. [Pg.51]

The details of the development of the EBRD process have been described by Pietsch et al.[187] There are two alternative operation modes in addition to the above continuous non-contact mode. The first one may be referred to as continuous contact atomization. In this mode, liquid metal contacts the bottom surface of the container instead of melt dripping, and then flows continuously from the center to the rim of the container. The second one may be termed discontinuous non-contact atomization. In this mode, the container is first filled by dripping melt while it is rotating at a very low speed of about 3 x 10-3 radians/s. The rotating speed of the container is then enhanced to about 14 radians/s while the metal or alloy is remelted and atomized. More than one focused electron beam may be used to provide energy for melting metal. [Pg.103]

The functional form of the nuclear longitudinal relaxation immediately suggests that the contact contribution can provide the values of the contact coupling constant and of 72e = Tso, provided that the lifetime, xm, is longer than T e- No information on the field dependence of electron relaxation can be achieved. On the contrary the functional form of transverse nuclear relaxation contains a non-dispersive term, Tig. The latter, as we have seen for the dipolar contribution, increases with increasing the field (Fig. 3), and therefore the nuclear contact transverse relaxation also increases with increasing the field. Its measurement is thus informative on the t value. [Pg.110]

The NMRD profiles of water solution of Ti(H20)g" have been shown in Section I.C.7 and have been already discussed. We only add here that the best fit procedures provide a constant of contact interaction of 4.5 MHz (61), and a distance of the twelve water protons from the metal ion of 2.62 A. If a 10% outer-sphere contribution is subtracted from the data, the distance increases to 2.67 A, which is a reasonably good value. The increase at high fields in the i 2 values cannot in this case be ascribed to the non-dispersive term present in the contact relaxation equation, as in other cases, because longitudinal measurements do not indicate field dependence in the electron relaxation time. Therefore they were related to chemical exchange contributions (see Eq. (3) of Chapter 2) and indicate values for tm equal to 4.2 X 10 s and 1.2 X 10 s at 293 and 308 K, respectively. [Pg.161]

One way to make this process somewhat more efficient is to adopt rigid structures for the various molecules. Thus, one does not attempt to perform geometry optimizations, but simply puts the molecules in some sort of contact and evaluates their interaction energies. To that extent, one needs only to evaluate non-bonded terms in the force field, like those... [Pg.62]

Once the Curie contribution to R2M is estimated and subtracted, the contribution of contact and dipolar interactions can be estimated by examining the correlation time dependence of the paramagnetic relaxation depicted in Figs. 3.9 and 3.11. It appears that the maximum for R m occurs at dipolar term and at contact term. Taking for simplicity xf Ip = r °", this means that in the intermediate situation where ft>s T p > 1 > relative importance of the contact term is even smaller than that estimated in the fast motion limit. The equation for R2M has non-dispersive terms in both the dipolar and contact contributions (accounting for one-fifth and one-half of the total effect measured in the fast motion limit respectively), and therefore the conclusions drawn in the fast motion limit are still qualitatively correct. [Pg.107]

A new ion source has been developed for rapid, non-contact analysis of materials at ambient pressure and at ground potential [8,9], The new source, termed direct analysis in real time (DART), is based on the atmospheric pressure interactions of long-lived electronic excited-state atoms or vibronic excited-state molecules with the sample and atmospheric gases. Figure 5 shows a schematic diagram of the DART ion source. [Pg.48]

The term non-impact applies to those processes which do not rely on pressure to transfer ink from the plate to substrate. Of these, ink-jet is a truly non-contact form of non-impact printing. [Pg.249]

This hyperfine coupling is of two kinds An isotropic interaction arises from the possibility that the electronic wave-function, x , be non-zero at the nucleus, N. This is the Fermi contact term and the hyperfine coupling constant is given by ... [Pg.294]

The microarray manufacturing method that enables microarray printing without direct contact to the surface is termed non-contact printing. Piezoelectric, bubble-generated, and microsolenoid driven pipettes as shown in Fig. 3 work with the same physical principle as ink-jet printers and are capa-... [Pg.7]

Figure 22 (r.h.s.) illustrates the contact thermodynamics and its influence on ionic and electronic carrier concentrations. The level bending expresses the variation in the electrical potential, and the constancy of //ion and /ieon the electronic and ionic contact equilibrium.35 (Note that the electric potential term—as a non-configurational term—is to be included into the energy levels .) The constancy of the chemical potential of the neutral component is automatically fulfilled (see Fig. 22 r.h.s.). [Pg.50]

The occurrence of hyperfine coupling for a particular isotope indicates non-zero spin density at that nucleus in accordance with the Fermi contact term (which includes the electron wave function evaluated at the nucleus) [1]. The analysis in terms of spin density then requires at least a comparison with the (calculated [5]) isotropic hyperfine splitting constant ao, ideally, results from increasingly available open-shell quantum-chemical calculation procedures [64] are employed. [Pg.1652]

Water Quality Standards (WQS) are defined for a given water body, associated with its main use and water quality criteria drinking water (treated and untreated), water based-recreation (non, short-term, long-term contact), fishing, aquatic life (warm or cold water species or habitat), agriculture and industrial water supplies. It includes... [Pg.18]

A very detailed study of 3/hcoh and other related coupling constants has recently been conducted.75 Zhao et al. performed DFT calculations on a series of aldopyr-anosyl model structures, many of which were deoxygenated at C-3, C-4, and/or C-6, so as to eliminate any undesired hydrogen bonding.75 DFT calculations were carried out with (a) only the Fermi contact contribution included and (b) non-Fermi contact terms included as well. For non-anomeric protons, inclusion of only the Fermi contact term resulted in a generalized Karplus equation ... [Pg.34]


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Contact term

Non-contact

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