Sample relaxation

Xj 1. The sample relaxes fast with the displacement from equilibrium synclnonous with the sound wave. 

Similar results were observed in the stress-relaxation experiments which are shown in Figure 2. The 5- and 10-day samples relax to the same stress level. The major difference in stress-relaxation behavior among the different samples occurs during the very beginning of the relaxation process. For that reason, and in order to better illustrate the first minutes of relaxation, the time scale is logarithmic. 

Peak shifts systematically with beam position on sample Relaxation... 

A little less obvious is the setting of the recycle delay RD (for NP-type sequences) or Tp (for PP-type sequences) which is linked through the factor f in Eqs. (3) and (4) to the estimated relaxation time Ti ax of the slowest-decaying component of sample magnetization at a specific field. One cannot influence the sample relaxation times, of course. On the other hand, the relaxation times usually dominate the overall duration of a single... 

However, certain assumptions must be made in order to derive the QSC. First, it is often assumed that the relaxation of Li is totally dominated by the quadrupole mechanism, i.e. T = r . If the relaxation of Li is measured on the same sample, relaxation contributions from other mechanisms can be eliminated . is related to QSC by equation 11 ... 

In the TSDC considered here, a sample is cooled to a low temperature ( 100K) and illuminated with 3 X 10 lx hght for a time tp ( 4min) in the presence of an applied DC field (E = 5 X 10" V/cm). Then, the light and voltage are switched off the structure is short-circuited and, after a delay period necessary for sample relaxation (to reach equihbrium between the free and the trapped carriers), the sample is heated in the darkness at a constant rate Vt while the TSDC is measured. We preferred TSDC experiments because of the absence of noise due to a voltage source and the strongly reduced influence of the intrinsic conductivity. 

The initial temperature gradients may be established in two general ways (1) if some part of the sample relaxes energy to the lattice rapidly it will cool and act as a sink for the remainder of the spin system and (2) it is sometimes possible to selectively heat a part of the spin system, as in Assinks use of the Goldman-Shen experimentJ. 

The sequence of events required for the measurement of CD by TLS proceeded as follows first, the sample was illuminated with one circularly polarized component of the pump field, the pump beam was then blocked, and the sample allowed to relax (heat dissipation). The probe laser experienced both the formation of the thermal lens (pump beam to cell) and the decay of the lens (pump beam blocked) during the two measurement cycles. During the next measurement sequence, the sample was illuminated with the other circularly polarized component, the lens measured as before, and the sample allowed to relax before the measurement cycle was begun again. As evident from Fig. 9, the chopper was designed to incorporate these various steps. In one complete revolution of the chopper, each circularly polarized component was individually passed to the sample while the other was blocked. In between these two measurement cycles, the chopper blocked both beams simultaneously to allow sample relaxation to occur. Based on thermal relaxation rates in water for this system, a modulation frequency of 2.3 Hz was used. 

In part B, by how much did your TD film elongate when measured under stress After you let the sample relax for 5 minutes, how much longer was the stretched region compared to the original 2 cm What were your results for the MD sample ... 

Due to the differences in the cross-flow generation compared with S-F1-FFF, and the possibility of sample focusing, the experimental methodology differs from that applied for most other FFF techniques (stop-flow for sample relaxation). Thus, a short description of an A-F1-FFF experiment as well as the whole experimental setup is necessary to understand its merits. 

Beside the frit inlets for Fl-FFF (see Fig. 12) which help to enhance the sample relaxation, Moon et al. have recently suggested a frit inlet which applies a small permeable frit near the injection point in the A-Fl-FFF channel [51,401 ]. As sample materials injected into the flow streams are hydrodynamically relaxed by the compressing action of high speed frit flow, the usual focusing relaxation procedure can be avoided which makes the experiment more reliable and faster. 

In contrast to creep, which is a constant stress experiment, stress relaxation is a constant strain experiment (and is usually somewhat easier to perform than a creep experiment)—Figure 13-76. A sample is deformed instantaneously (well, almost instantaneously) to a given value of the strain and the stress required to maintain that deformation is measured as a function of time. As the sample relaxes (i.e., as the chains change their conformations, disentangle and slide over one another) this stress decreases. 

Precautions must be taken in all FFF analysis when injecting a large amount of material with any injection technique. During the sample relaxation, local concen-... 

In samples relaxing through nuclear-nuclear dipole-dipole mechanisms, another source of error in quantitative 13C-NMR is the nuclear Overhauser effect. This arises in double resonance experiments when one nucleus (in this case 1h) is irradiated to simplify the spectrum while another (in this case is observed. 

While the most common approach to sample relaxation data is to record the NMR relaxation time as a function of temperature and make use of the temperature-frequency... 

Q) SAMPLING-RELAXATION (b) FLOW-ENHANCED (c) SMALL SOLUTES (d) LARGE SOLUTES NO FLOW SEPARATION ELUTE ELUTE... 

The determination of such NMR relaxation times as T p is a well-established technique to probe the degree of mixing and the presence of phase separation in a sample. Relaxation in the rotating frame is governed by fluctuating local fields in the kHz range. The decrease in signal intensities for Gly C and C=0, Ala C , Cf and C=0 of B. mori with silk II form and S.c. ricini with a-helix form as a function of spin-lock time (between 0 and 20 ms) in the resonant rf fields of... 

C. The early ones had tube electronics and you had manually to try to maintain a tension as the sample relaxed during a thermal scan. 

When I(t) is constant, as will be the case at long times after all the transients associated with sample relaxation have died out, Eq. (40) reduces to... 

Sample Relaxation dimensional change in area shrinkage (%) Consolidation dimensional change in area shrinkage (%) Felting dimensional change in area shrinkage (%)... 

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