Retarded response

Thompson, T, Hackenherg, T, Cerutti, D., Baker, D., and Axtell, S. (1994) Opioid antagonist effects on self-injury in adults with mental retardation response form and location as determinants of medication effects. Am J Ment Retard 99 85—102. 

Figure 1 If NTA in Greifensee were nonreactive, then the difference between the measured concentration (3.7 x 10 9 M) and the predicted steady-state concentration (38 xlO 9M) had to be interpreted as the retarded response to an exponential increase of NTA input into the lake with the unrealistically large growth rate a = 7.5 yr. ...

The shape of the creep and recoil curves provide insight about the sample, as does the stress relaxation response. A very strongly curved retardation response resembling a square wave is indicative of dominantly elastic behavior. A stress relaxation response for an elastic solid gives an almost horizontal line with very little decay, because almost all the energy is stored. A creep recoil curve that almost returns to the initial state of zero compliance is indicative of a very elastic system, because stored energy is almost completely recovered. 

A linear output is associated with a liquidlike or viscous response. The retardation response of a Newtonian liquid is a straight line through the origin, where the slope of the line is inversely proportional to the viscosity. A stress relaxation response for a Newtonian liquid is a narrow spike, as energy is dissipated very quickly. Typically the recoil part of a creep curve will be almost horizontal if there is little elasticity in the sample. 

Response functions. The elementary Cooper and Peierls logarithmic divergences (19) of the interacting electron gas are also present order by order in the perturbation theory of response functions in the 2kf density-wave and superconducting channels. A scaling procedure can thus be applied in order to obtain the asymptotic properties of the real part of the retarded response functions which we will note Xm.( )- is convenient to introduce auxiliary response functions noted x ( ) [107], which are defined... 

Semisolid foods belong, in general, to a group than can be characterized by viscoelastic parameters. Viscoelasticity is due to the delayed motion and retarded response of a system to a shear resulting from a joint viscous and elastic nature. Jellies and deserts fall into this category. Jams are also included however, some additional measure of elasticity of the product is required. 

Cannibalistic (fused) alite Erratic thickening times and unpredictable retarder response (Reeves, Bailey, and McNabb, 1984) reduced activity level (Dorn, 1985)... 

T. Thompson, T. Hackenberg, D. Ceiruti, D. Baker, and S. Axtell, Opioid Antagonist Effects on Self-injury in Adults with Mental Retardation Response Form and Location as Determinants of Medication Effects. Am. J. Mental Retardation, 99,85-102,1994. 

If the carboxyhaemoglobin (CO-Hb) content in terms of total haemoglobin is below 10 per cent in human blood, no symptoms appear except for some loss in discernment and somewhat retarded responses. Between 10 and 30 per cent, severe headache and heart throbbing develop from 30 to 50 per cent, breathing rate increases, cardiac action becomes arrythmic and collapse is possible 70 to 80 per cent leads to death within an hour or two. 

The quasi-liquid state (ql) [50, 52,120] only exists in polymers and is localized at the transition between the glass and the melt, where low mobility and a retarded response to external forces are observed. The low mobility distinguishes this state from a low molar mass (ordinary) liquid which flows much more rapidly under comparable conditions. The retarded mechanical response compares with the leathery state of an elastomer (e.g. Chapter 1 in reference 92). In the present case the ql phase originates from PET. This is also the state in which cold crystallization occurs. The temperature of maximum cold crystallization is indicated in Figure 9.25. 

Q-1 shows an analogy with the leatheiy state in the elastomers. Both types of systems are immediately above their glass transition regions, and both exhibit retarded responses to application of external forces. 

In terms of chemical composition. Class G and Class H oil well cements are low-CgA Portland cements, and the specifications of both are typically met by high-iron, sulfate-resistant Portland cements (see also section 2.8). The free lime content in these cements is not limited by the API specifications, but it should be below 0.5 wt% to avoid difficulties with cement slurty rheology and retarder response. In producing Class G and Class H oil well cements, iron oxide (in the form of hematite or pyrites residues) must usually be added to the raw mix to produce more ferrite phase at the expense of tricalcium aluminate. The required amount of Fe203 is greater when a cement of HSR rather than MSR grade is produced. 

In contrast to the Cloisite clays, addition of phosphate-coated clays was able to improve the flame retardant response in certain classes of polymers. For example, addition of 5% RDP-coated clays to PC was able to achieve a UL-94 VI rating, whereas the addition of Cloisite 20A failed. Similarly, addition of 10% RDP-coated clays to HIPS achieved a rating of VI, whereas no effect was observed with Cloisite clays. 

For a viscoelastic system, the compliance shows a rapid elastic response Jo at t —> 0 [instantaneous compliance Jo = 1/Gq, where Go is the instantaneous modulus, which is a measure of the elastic (i.e. solid-hke ) component]. At 0, J increases slowly with time and this corresponds to the retarded response ( bonds are broken and reformed but not at the same rate). Above a certain time period (which depends on the system), the compliance shows a hnear increase with time (i.e. the system reaches a steady state with constant shear rate). If, after the steady state is reached, the stress is removed elastic recovery occurs and the strain changes sign. 

In constant stress (creep) measurements, one applies the stress (that is kept constant at each measurement) in small increasing increments. If the stress applied is below the yield stress, the system behaves as a viscoelastic solid. In this case, the strain shows a small increase at zero time and this strain remains virtually constant over the duration of the experiment (near zero shear rate). When the stress is removed, the strain returns back to zero. This behaviour will be the same at increasing stress values, provided the applied stress is stiH below the yield stress. Any increase in stress will be accompanied by an increase in strain at zero time. However, when the stress exceeds the yield stress, the system behaves as a viscoelastic liquid. In this case, the strain rapidly increases at zero time, giving a rapid elastic response characterised by an instantaneous compliance Jo (the compliance is simply the ratio between the strain and applied stress, Pa ). At time larger than zero, the strain shows a gradual and slow increase with time. This is the region of retarded response (bonds are broken and reformed at different rates). Ultimately,... 

Here t is called the retardation time, since it characterises the retarded response of the model, and its value is again given by r /G. At very short times, the response is viscous, and y ta/r. At f = t, the strain has risen to 63 % of its final, asymptotic value of a/G. 

A Wilms tumor can occur as part of complex disorder like the WAGR syndrome with Wilms tumor, aniridia, genital malformation and mental retardation. Responsible genes are in close vicinity on chromosome 11 in the region pl3 (WTl) and pl5.5 Mutation in the gene were found in... 

Orientational polarization, as it is found in polar liquids, provides a good example for explaining the physical background of reversible retarded responses. First consider the natural state without a field. Here we have no polarization, and this arises from distributing the orientations of the polar units in the sample isotropically. If now an electric field is applied, the orientational distribution changes. Since dipole orientations in the field direction are preferred, the distribution function becomes anisotropic. As a consequence we find a non-vanishing value for the orientational polarization Por-... 

As we have seen, the time dependence of a macroscopic relaxation process always reflects the underlying microscopic dynamics. We may now proceed and look for kinetical equations which correctly describe the time dependence of the observed retarded responses. 

The schematic strain retardation response to of the Burgers model to a step-function stress input is illustrated in 34.4. 

The Maxwell model is incapable of describing the creep behavior because it cannot model the retarded response under a constant stress. The Kelvin-Voigt model (Figure 16.21), consisting of an ideal spring and an ideal dashpot connected in... 

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