G, value

The simplest system exliibiting a nuclear hyperfme interaction is the hydrogen atom with a coupling constant of 1420 MHz. If different isotopes of the same element exhibit hyperfme couplings, their ratio is detemiined by the ratio of the nuclear g-values. Small deviations from this ratio may occur for the Femii contact interaction, since the electron spin probes the inner stmcture of the nucleus if it is in an s orbital. However, this so-called hyperfme anomaly is usually smaller than 1 %. 

The negative sign in equation (b 1.15.26) implies that, unlike the case for electron spins, states with larger magnetic quantum number have smaller energy for g O. In contrast to the g-value in EPR experiments, g is an inlierent property of the nucleus. NMR resonances are not easily detected in paramagnetic systems because of sensitivity problems and increased linewidths caused by the presence of unpaired electron spins. 

Here gk is the so-ealled nuelear g-value of the nueleus, H is the strength of the applied... 

Fig. 4. Diagram of a hoUow-fiber ultrafilter filtration system where A corresponds to the retentate reservoir B, circulation pump C, pressure gauge at module inlet D, ultrafilter module E, permeate reservoir F, pressure gauge at module outlet G, value to control module outlet pressure and H, drain...

Numbers on lines represent G values = gas flow in kg/(m -s) = nominal packing size = superficial velocity. To convert kg/(m -s) to lb/(h-ft )... 

When kc and K g values are reported in units (SI) of kmoL/[(s m") (kPa)], one must be careful in converting them to a mole-fracdion basis to multiply by the total pressure actually employed in the original experiments and not by the total pressure or the system to Be designed. This conversion is valid for systems in which Dalton s law of partial pressures p = ypr) is valid. 

Optimum mixing usually requires a G value of greater than 1000 inverse seconds. Optimum flocculation occurs when G is in the range 10-100 inverse seconds. 

From a knowledge of various values of P it is possible to calculate F values for specific polymers and G values for specific gases if the G value for one of the gases, usually nitrogen, is taken as unity. These values are generally found to be accurate within a factor of 2 for gases but urtreliable with water vapour. Some... 

From the experimental data for the free resulting jet, the g value in Eq, (7.162) is equal to 0.075. Tests in field showed that the influence of the re-... 

CNTs are purified by oxidizing the crude ones as prepared. During the oxidation process, the nanoparticles are removed gradually and eventually only open CNTs remain [9]. An intrinsic CESR was observed from these purified COTs [12]. The temperature dependencies of susceptibility, linewidth and g-value of the CESR are shown in Fig. 2 (open circle). We find a temperature independent spin susceptibility (Pauli) = 4.3 x 10 emu/g. 

Fig. 2. Temperature dependencies of spin susceptibilities, linewidths and g-values of the CESR for the purified CNTs (open circle) and the annealed purified CNTs (solid circle).

Pauli spin susceptibility for the aligned CNTs has been measured and it is reported that the aligned CNTs are also metallic or semimetallic [30]. The temperature dependence of gn and gx s plotted in Fig. 5(a). Both values increase with decreasing temperature down to 40 K. A similar increase is observed for graphite. The g-value dependence on the angle 0 at 300 K is shown in Fig. 5(b) (inset). The g-value varies between gn = 2.0137 and gx= 2.0103 while the direction of magnetic fields changes from parallel to perpendicular to the tubes. These observed data fit well as... 

In the simple model of CNTs described earlier, its g-value can be estimated using the g-values of graphite at 300 K,... 

The XRD peaks characteristic of Co and Ni disappeared after the treatment, as did the broad ESR line, successfully leaving only the narrow asymmetric line with 26 G linewidth as shown in Fig. 8 [40]. The g-value of the narrow line is =2.002 0.001. The narrow ESR line shows Dysonian at all temperatures in the range of 4-300 K. Furthermore, the ESR intensity is quite independent of T and thus the density of conduction electrons is invariant as a function of temperature as shown in Fig. 9. These show that the material is highly metallic, even at low 7. 

Tlie following summarizes g-values and hyperfine splitting values by ( h) and by ( 33s) in natural abundance for the representative 1,2-dithiete radical cations. 

Consequently, AG is defined by Cc coefficient as well as by the change of element deflection, labor over the system, and the number of intermolecular bonds. The value of Cc approaches the A G value observed in similar reactions with the participation of only low-molecular compounds. As intermolecular bonds are distributed in elements according to Gibbs distribution, then chain parts between the molecular bonds and branching points possess different lengths in which the lengths of nonassociated parts are also different. Gibbs distribution is only performed in polymer equilibrium, which usually exists in so-called stationary states. 

The theory of radiation-induced grafting has received extensive treatment. The direct effect of ionizing radiation in material is to produce active radical sites. A material s sensitivity to radiation ionization is reflected in its G value, which represents the number of radicals in a specific type (e.g., peroxy or allyl) produced in the material per 100 eV of energy absorbed. For example, the G value of poly(vinyl chloride) is 10-15, of PE is 6-8, and of polystyrene is 1.5-3. Regarding monomers, the G value of methyl methacrylate is 11.5, of acrylonitrile is 5.6, and of styrene is >0.69. 

The rate of free radical production from Am and B are dependent on the G value of both ... 

Ionizing radiation is unselective and has its effect on the monomer, the polymer, the solvent, and any other substances present in the system. The radiation sensitivity of a substrate is measured in terms of its G value or free radical yield G(R). Since radiation-induced grafting proceeds by generation of free radicals on the polymer as well as on the monomer, the highest graft yield is obtained when the free radical yield for the polymer is much greater than that for the monomer. Hence, the free radical yield plays an important role in grafting process [85]. 

Shear modulus is also changed with the blending type (Fig. 11). Preheated blends provide higher modulus than the preblends. It is obvious that shear modulus either decreases or remains the same at the initial level of NBR for preblends, but beyond 45% of NBR there is a further rise in the G value irrespective of shear rates whereas at the lower shear rate, preheated blends show the continuous rise in the shear modulus for the entire composition range. 

The shear modulus varies with the blend ratios in the preblend system, G remains constant up to 50 50 blend ratio and then it decreased with the further addition of AU in the blend at higher shear rate. At lower shear rate, G increased up to the 50 50 blend ratio and then it fell. Preheating of the blends resulted in increasing the G values. At both shear rates G increased up to 50 50 blend ratio and then decreased with further addition of AU in the blends. 

---