Initial rise method

The principal trap parameter, the activation energy, can be easily calculated from a single TSDC experiment by means of some characteristic elements of the peak, such as its half-width, inflection point, or initial part of current rise. The most useful one and, in fact, the most frequently exploited, is nndonbtedly the initial rise method [20], because it is always easily applied to a previously cleaned peak. 

The initial rise method is based on the fact that becanse the integral term in the J-d T) function (for details, see Ref. [9]) is negligible at T T, the first exponential dominates the temperature rise of the initial cnrrent, so that... 

Values of activation energy calculated by the initial rise method are in the range 0.25-0.45 eV. Continuous distribution of locahzed states in this range was confirmed by an increase of activation energy in a sequence—curves 2-4 (Fig. 2.6). 

For the characterization of the trap levels we applied the thermally stimulated current technique following the initial rise method [26] which was successfully applied to other conjugated polymers [27]. The device consisted of a sapphire substrate with an interdigital gold electrode structure on top of which a 200 nm thick polymer film was drop-cast. The gold electrodes had an overall length of... 

The thermal cleaning method and partial heating are known as experimental separation methods of composite TSC spectrum and only initial rising part of TSC spectrum was used for estimation of Et value. The initial rise method(Garlick Gibson,1948) is the only one procedure to apply to data without a peak until now. However, in AEM-o, an application is possible to an omniformity-shaped TSG spectrum. 

The aim of this work is to analyze the changes in the relevant thermal behavior of the crosslinked EVA encapsulant material due to outdoor exposure in Mediterranean climate by TSC and DSC thermal analysis. The changes in thermal properties should be discussed and special interest will be focused on the specific TSC relaxation parameters like activation energy and relaxation frequency determination by using the initial rise method. 

For the determination of the characteristic parameters of the process i.e. the activation energy and the relaxation time factor, the initial rise method is mostly used. This method is based on the fact that for restricted conditions [ 15], the current density during a thermal stimulated measurement can be expressed by Arrhenius equation. From TSDC curves in Fig. 12, under polarization temperature of 0 °C, the... 

The activation energy (E) responsible for the process can be calculated from the slope of the straight line obt ed from /j(7) versus 1/7 plotted u suggested by the initial rise method of Oartidi and Gibson [289], A low value of is obtained when there is a distribution in relaxation. It requires separation of the individual peaks when different processes overlap and give a sin TSD peak. 

It is simpler, though less exact, to apply the extrapolation method. The part of the residual current curve preceding the initial rise of the wave is extrapolated a line parallel to it is drawn through the diffusion current plateau as shown in Fig. 16.6(h). For succeeding waves, the diffusion current plateau of the preceding wave is used as a pseudo-residual current curve. 

Shizgal et al. (1989) have criticized the displaced pseudo-Maxwellian (DPM) method because that approximation gives too fast an initial rise of electron temperature (velocity randomization), does not distinguish between longitudinal and... 

The activation energy E associated with the peak at T = 150K has been calculated by the preceding method, i.e., plotting log I against HE from the initial rise of the curves. Such a plot for Vt = 0.08 K/s is shown in Fig. 2.4. The activation energy obtained by this method is 0.22 eV. 

While determining the liquid height, it is better to measure with a falling (or receding) meniscus, so that the liquid level is initially raised above its equilibrium value by a slight suction above the capillary tube, and then left to equilibrate. On the other hand, two-armed capillary tubes, connected with a cross tube above the liquid level, are also used to ensure that the pressure in both arms of the glass apparatus is the same. An interesting modification of the capillary rise method is to measure the pressure, AP, that is required to force the meniscus down until it is on the same level as the plane surface of liquid outside the capillary tube. This method is useful to compare the surface tension of water and its dilute solutions. 

Earlier, it was noticed that the evaluation of the Fq by using a simple linear extrapolation of the initial Fy fluorescence rise can be significantly affected by the slope of the initial fluorescence rise (3). Therefore, it is essential to determine the validity of the Fq estimation when the slope of the initial fluorescence is different. In order to do this, we evaluated the Fq values when the initial kinetics rise were changed due to the addition of different electron acceptors. The Fig 2a, b and c represents the fluorescence induction curves of barley chloroplasts in the presence of different concentrations of the electron acceptors BQ, FeCN, and MV. The Fy values were quenched dependently to the concentrations of the electron acceptors, consequently, the quenching intensity Fy had different fluorescence initial rises and total fluorescence yields (Fig 2d) which resulted from the rate of the PSII primary electron acceptor Qa reduction (1). By using the least square regression method, we estimated an unchanged Fq value when the initial fluorescence rises were different (Fig 2d). This indicates that, when the chloroplasts were... 

In selecting a given instrument for a specific purpose, the user should take into account the nature of the analyte, the most suitable species for measuring its concentration, and the type of reaction involved and its half-life. Also, the response time should be short enough for the signal to be as close as possible in time to the event that gives rise to it, especially with fast reactions or initial-rate methods. 

The initial-rise (ir) method. From eq. (5) it is clear that at the very beginning of a TL peak, when n and m remain practically unchanged, the TL intensity should rise exponentially with T, I (xp=s exp( /L7 ). A plot of log/ as a function of the reciprocal temperature (T ) should then give a straight line from which E can be determined. 

Furetta and Gennai (1981) obtained for the dosimetric peak 0.8 eV from the initial rise and 0.94 eV from the variable heating rate method. 

Let us analyze [283, 285] the influence of the mutual locations of the heat sources and temperature sensors on the value of the energy equivalent for a calorimeter treated as a system of two domains. As stated previously, in the corrected temperature rise method three periods are distinguished during the experiment < to, t >- initial < ti, t2>- main and < t2, tf> - final. In the initial and final periods, the calorimeter is a thermally inert object in the main period, the heat effect is generated in the calorimeter. 

The formation of the complex between PA and DM-)8-CD was studied by a solubility method. Figure 1 shows an equilibrium phase solubility diagram obtained for the PA/DM-yS-CD system in buffer solution at pH 7.4. The plot shows a typical Bj-type solubility curve. The initial rising portion is followed by a plateau region and then decreases in total concentration of PA with precipitation of a microcrystalline complex at a high DM- S-CD concentration. The stoichiometry of the complex was found to be 1 2 (PA DM-y5-CD) from the PA content. 

It is possible, however, to get more useful information on streamer initiation the method consists of, under a rectangular voltage, measuring t, defined as the time at which a small optical perturbation (e.g., < 10 ym in diameter) is detectable by the Schlieren technique, or by light emission, or also by current measurements characteristic of the early streamer propagation. It was shown that when the rise time of the voltage was much lower than t, for several liquids, initiation times were shorter with the positive point than with the negative point, but from the V-t curves it was only deduced that one mechanism appeared to be rejected-cavitation, as will be discussed later - and it was not feasible... 

Figure 6.25b indicates that the maximum and steady-state values of the proposed method are lower than those for individual grounding. Because the varistor has a capacitance of hundreds of picofarads, the initial rise slows down, which indicates that the proposed method can reduce an LS better than individual grounding can. 

The second method is known as the slow rate-of-rise method. The test is carried out by applying the initial voltage approximately equal to 50 percent of the breakdown voltage, as determined by the short-time test or as specified. Next, the voltage is increased at a uniform rate until the breakdown occurs. 

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