Variation of Frequency

All the examples presented so far have been at the frequency / = 7.7 GHZ. The effect of changing the frequency will be investigated next. The size of the array 

SURFACE WAVES ON PASSIVE SURFACES OF FINITE EXTENT 

We are closer to the resonant frequency 10 GHz), resulting in a stronger column current and thus backscattered field. 

The sidelobe level of the backscattered field is higher because we are getting closer to the onset of the first grating lobe ( 18 GHz). 

But how do we explain that surface waves are present only in a limited frequency range, namely 6.3-8.3GHz This is explained in Fig. 4.16 in a qualitative way. It shows the scan impedance plotted earher in Fig. 4.2 but here plotted at three frequencies, namely 6, 7.7, and 10 GHz. Furthermore, these scan impedance curves are shown a bit more realistic by the fact that they for end-fire condition do no go to infinity but just to a large value depending on how large the array actually is. This point is easy to see by application of the mutual impedance concept. It simply tells that the magnitude Za of the scan impedance can never exceed Ylq=-Q Zo, , where Zo,q is the mutual impedance between the reference element in column 0 and all the elements in column q (see Chapter 3 for details). Since Zo, j and Q are bounded, so is the finite sum Za. As already shown in Fig. 4.2 and repeated in Fig. 4.16 for easy comparison, we 

---

An analogous variation of frequency of the nonnal inodes occurs in poly atomics. 

The parameters included in /3 are the particle density, the adhesion, and the power dissipated by the crystal. Thus, the variation of frequency provides some means for discrimination based on the particle size. The sensitivity decreases for particles with diameter greater than 2 pm and no sensitivity is obtained for particles larger than D 20 pm. 

The squares of the normalized coefficients c, . . ., c directly give the fractions of the original intensity in transitions to each one of the four states. We may reasonably neglect variations of frequency between the transitions in converting transition moments to intensities because the frequency range of the transitions is small. Typical results are given in Table I. 

Fig. 7.3. Experiment designed to test if cross-fertilisation occurred with Hymenotepis diminuta. An Fi0 variant (with a testicular variation frequency of 31.7%) and a normal worm (variation frequency 2.5%) were simultaneously implanted into the duodenum of a rat. After worms became patent at 16 days post-implantation, the terminal gravid proglottides were removed and fed to separate groups of beetles. The resultant cysticercoids were fed to groups of 10 rats (one cysticercoid per rat). Analysis of the Ft worms revealed a statistically significant increase in the variation of frequency in the progeny of the normal worm and a statistically significant decrease in the variation frequency of the variant (Fi0) individual. (Compare xf= 17.6% with 4.1% in the implanted worms and with 2.5% in the original worms before implantation. (After Schiller, 1974.)...

Recent theoretical treatments of the soft-mode behaviour include a detailed study by Onodera using classical mechanics, and a theory of hydrogen-bond mechanics, including tunnelling effects, by Stamenkovic and Novakovic. ° Onodera assumes a quartic potential function for his individual oscillators, with a bilinear interaction which reduces to c x, where x is the displacement, under the Weiss-molecular-field approximation. The model is soluble without further approximation (in series of elliptic functions), yielding the temperature variation of frequency and damping. If the quartic potential has a central hump larger than kTc,... 

The detection performance of the molecular sieve coated sensor is examined from the measurement of frequency variation while different concentrations of organic vapor contained air are contacted to the sensor sur e. While organic vapor contained air flows continuously with constant flow rate of 0.4 IVmin., the variation of frequency is monitored and the outcome is converted to the organic concentration. In order to examine the process of adsorption and desorption of the organic vapor on the molecular sieve coated on the sensor surface, fresh air and organic substance contained air are alternately provided. 

Figure 3. Variation of frequency with various concentration of methanol contained air.

The corrected Raman spectra of nonnal and shock-densified Si02 glasses aie shown in Fig. 3.11. The Raman bands show significant pressure variations m frequency, bandwidth, and relative intensity (Fig. 3.12). The broad band iieai 455 cm t shows large variations of frequency and width. Generally, there is an inverse correlation between the frequency of this band and the Si O-Si ang.le... 

Figure 12. Variation of frequency squared for the soft optic mode through the tetragonal o orthorhombic transition in stishovite (data from Kingma et al. 1995). Straight lines through the data intersect at P = 51.6 GPa the straight line for tetragonal stishovite extrapolates to zero at = 102.3 GPa. A broken line for the orthorhombic phase includes the pressure dependence of b but is barely distinguishable from the straight line fit to the data (solid line). After Carpenter et al. (2000a).

Figure 18 Variation of frequency of bending of proton donor molecule v, and H-bond stretching frequency as a function of calculated interaction energy. Systems included come from Tables 3 and 4, along with supplementary data for the following...

For microporous solids, the bands from framework vibrations depend on both the structure type and the composition. For zeolites, substitution of framework aluminium results in broadening of these bands and a shift to lower wavenumber, which is attributable to the Al-O bonds being weaker than Si-O bonds. As a result, and once the variation of frequency with composition of a certain framework stretching vibration (symmetric or asymmetric... 

When protonation occurs, there is no doubt that P2VP, P4VP and Paam are N-protonated whereas PVP is O-protonated. However, the polyamides present a specific feature. The well-known electron delocalization along the 0=C—N amide group is highly perturbed as revealed by large variations of frequency and intensity of the amide 1 (vC=0) and amide III (vC-N) IR absorptions. 

Variation of frequency may be achieved in a single AC voltammetric experiment by applying a periodic waveform, which contains several carefully selected frequencies [33]. 

It was remarkable that SPNR containing very low both protein and fatty acid content showed much easier processability, i.e. higher tan 8, than DPNR and NR while the processability of DPNR containing low proteins but relatively high fatty acid ester was not considerably different from that of NR as seen from comparative tan 8 of the samples kept for 3 and 6 months measured at variation of frequency and strain shown in Figure 18.1. 

However in more complexing solvents (e.g. 1-methylnaphthalene) this is no longer the case the donor side (cr <0) is still straight ( =2.44) but the acceptor side (g >0) is curved downwards. This shows that when specific solute-solvent interactions are present the solvent effects on free energy relationships are rather complex and they cannot be treated in terms of new q values g fixed) alone as it is generally made [67]. Similar considerations prevail for the variation of frequency and intensity of carbonyl group vibrations (both symmetrical and asymmetrical) with substituents [to be published]. 

F = determinedfrom variation of Frequency (only data obtained at frequencies < 25 Hz were used)... 

Variation of frequency within the range of 1 Hz-2 Hz has no impact regarding the reliability parameters. 

The existence of biphasic (mixture of solid and liquid phase even in molten state) nature makes the rheological properties of LCPs extraordinary. For crystalline polymers, the modulus depends on the degree of crystallinity. The degree of crystallinity for LCPs also change with the variation of frequency as well as temperature (Dae Han and Kim 1993). The amorphous portions go through the glass transition, but the crystalline portirMi remains hard. Thus a composite modulus is found for LCPs. 

Variation of frequency (Hz) with OR for AV119 (series 1) and 9245 (series 2) singie iap joints in their first free-free mode of fiexurai vibration... 

---