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Retarding moment

Scheme of a rotational pendulum of mass (mt) bearing a ring slit with radii (Rj, RJ and height (d) which can be loaded with sorbent material of mass (m ). The torsional wire of length (L,) and diameter (2r, ) has a retarding moment (Do) and internal damping coefficient (Ro). [Pg.240]

As the mechanical properties of the torsional wire (retarding moment, internal damping, length) depend on temperature, calibration of the pendulum is necessary for all temperatures at which measurements should... [Pg.276]

In spite of the good results obtained we continue our search for simple auxiliary conditions directed at ensuring that the approximated matrix is positive and that its trace has the correct value. This search is mainly focused at improving the quality of the 2-RDM obtained in terms of the 1-7 DM, which at the moment is the less precise procedure [46]. When this latter aim is fulfilled we expect that the iterative solution of the 1-order CSchE will also be successful although in this CSchE the information carried by the Hamiltonian only influences the result in an average way which probably will retard the convergence. [Pg.73]

For initiated oxidation, the inhibitory criterion could be defined as the ratio v0/v or (v0/ v — v/v0), where v0 and v are the rates of initiated oxidation in the absence and presence of the fixed concentration of an inhibitor, respectively. Another criterion could be defined as the ratio of the inhibition coefficient of the combined action of a few antioxidants / to the sum of the inhibition coefficients of individual antioxidants when the conditions of oxidation are fixed (fx = IfiXi where f, and x, are the inhibition coefficient and molar fraction of z th antioxidant terminating the chain). It should, however, be noted that synergism during initiated oxidation seldom takes place and is typical of autoxidation, where the main source of radicals is formed hydroperoxide. It is virtually impossible to measure the initial rate in the presence of inhibitors in such experiments. Hence, inhibitory effects of individual inhibitors and their mixtures are usually evaluated from the duration of retardation (induction period), which equals the span of time elapsed from the onset of experiment to the moment of consumption of a certain amount of oxygen or attainment of a certain, well-measurable rate of oxidation. Then three aforementioned cases of autoxidation response to inhibitors can be described by the following inequalities (r is the induction period of a mixture of antioxidants). [Pg.619]

Earlier, the first studies by Cockbain and McRoberts (C7) indicated that the time necessary for coalescing, measured from the point that the drop apparently has come to rest on the flat interface till the moment the first coalescence sets in, is spread statistically around an average value. Both the standard deviation and the mean value depend on the phase system and decrease with increasing temperature and with decreasing drop size, while surface active agents and small impurities that collect at the interface have a strong retarding effect. [Pg.296]

The study of the relaxation of dipole polarization, as well as of the dipole moments of cholesterol-containing polymers and copolymers128 "134,191 193) presents a sensitive confirmation for the existence of intramolecular structuration of mesogenic groups. This is indicated for instance, by the high values of relaxation times (Tjj p) and activation energy (EJ p) of dipole polarization, as well as by the large values of correlation parameter g, which is a relative measure of the internal rotational retardation in macromolecules (Table 18). [Pg.245]

The existence of the functional dependency of Eq. (8) provides a possibility411 to assume that relaxation processes develop in time similarly after different homogeneous extensions (and even after a preliminary partial relaxation of stresses), if the accumulated elastic strain a and irreversible strain velocity ep in the medium are similar at the moment of start of relaxation. According to the above, we can take, for example, instead of parameters (a, e ) parameters (cr, a). If the processes of stress relaxation coincide in time, the processes of retardation occur automatically similarly under the same initial conditions of (at, e ). [Pg.10]

It has been demonstrated that the oxidation of alcohols with hexacyanoferrate(III) (HCF) shows a hyperbolic variation with HCF concentration, and the reaction order varies from one to zero on increasing the HCF concentration. This rate law is obeyed during the initial moments of the reaction and at any subsequent time. These results rule out the possibility that any substance produced during the course of the reaction acts as an activator or inhibitor of the reaction rate. The mixed order has been attributed to the comparable rates of complex decomposition and catalyst regeneration steps.86 HCF acts as a selective oxidizing agent for the oxidation of catechols even in the presence of 2-mercaptobenzoxazole, as an easily oxidizable thiol, to produce related catechol thio ethers.87 Hexacyanoferrate(II) has a retarding effect on the oxidation of vanillin with HCF in alkaline solutions. A mechanism based on the observed kinetics has been proposed 88... [Pg.101]

If the retardation of the temperature grating is neglected for the moment, which is valid if A t > T, a sinusoidal amplitude modulation of the optical grating translates directly into a sinusoidal amplitude modulation of the temperature grating with amplitude 5 T = % al0 (pc ) 1 according to Eq. (16) ... [Pg.40]

Atomic core polarization e -p correlation Yamazaki and Ohtsuki [5] emphasized the important role of a special type of configuration mixing which contributes to a substantial reduction of the radiative transition rate. This effect is essentially the same as in the nuclear core polarization phenomena, where low energy transition moments are affected by the presence of high excitation mode (giant resonances). In the present case, the low energy El transitions ( 2 eV) are retarded by a factor of 3 by the existence of the hard electronic excitation ( 20 eV). [Pg.248]

This extraction precisely reproduces the same London, Debye, and Keesom interactions, including all relativistic retardation terms that had been effortfully derived in earlier formulations. These interactions are distinguished by whether they involve the interaction of two permanent dipoles of moment //.uipoie, or involve an inducible polarizability aind. A water molecule, for example, has both a permanent dipole moment and inducible polarizability. The contribution of each water molecule to the total dielectric response is a sum of the form of Eqs. (L2.163) and (L2.173) in mks units,... [Pg.86]

Under conditions where eqn. (3) holds, inhibition occurs as described in Chap. 6, Sect. 1.4. In cases described by eqn. (4), only low polymers will be formed at an undiminished rate (when very short chains are formed, the rate of oligomerization might even increase). Chains shortened by transfer will also be formed at an undiminished rate in case of eqn. (6). Perhaps the most interesting is the situation described by eqn. (5). Transfer is accompanied by slow re-initiation. A part of the active centres is present in an inactivated form. Thus, at a given moment, fewer chains are growing and monomer consumption is slower. With stationary polymerizations, the external manifestations of this situation are called retardation. For various reasons, a stationary polymerization may change to a non-stationary one due to transfer. Such cases are described as degradative transfer (see Fig. 1). [Pg.444]


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See also in sourсe #XX -- [ Pg.251 ]




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