Specimen heating

Fig. 7. Thermal conductivity data for CBCF specimens heat treated for 10 seconds (5.7 seconds at temperature) at four different temperatures. Solid lines are predicted curves from Eqs. (5) through (8). Reprinted from [14], copyright 1996 Technomic Publishing Company, Inc., with permission.

A similar unit, modified in details such as location of condenser, use of an agitator and shape of the vessel, was used by Fisher and Whitney . Further substantial modifications to permit interface location of specimens, cooling of specimens and operation under applied pressure, have been described by Fisher . Earlier laboratory test methods tried by Fisher and Whitney included exposure of specimens heated by their own electrical resistance and of tubular specimens containing a pencil-type resistance-wire heater in a quartz tube. 

Mitchell, P.H. (1988). Irreversible property changes of small loblolly pine specimens heated in air, nitrogen, or oxygen. Wood and Fiber Science, 20(3), 320-355. 

With respect to the higher temperature transition at 445 °C, there are two conflicting views of this transition, namely that the phase above 445 °C is a smectic C and the other that it is nematic. Based on high temperature X-ray diffraction studies, Yoon et al. have concluded that it is a smectic C (see Fig. 4) [28], Thus, in Fig. 4, the disappearance of the 211 peak indicates that the nematic E structure is converting to a nematic C. In our work, using polarizing optical microscopy, we have observed a nematic texture for high molar mass specimens heated rapidly to 480 °C, sheared, and then quenched. In the case of a... 

Phase contrast photomicrographs for a 50% polyblend are shown in Figure 7. The granular structure and the changes with temperature in the relative content of light vs. dark regions are noticeable. Also, note that the specimen heated above 120°C. retained its appearance when cooled to room temperature (Figure 8). 

Babrauskas V. Specimen heat fluxes for bench-scale heat release rate testing. Fire Mater. 1995 19 243-252. 

CRYSTALLINITY Index. The crystallinity indexes for specimens heated under each set of conditions (LO, DO, LN, and DN) at each temperature from the first exposure time (ti) to the last or seventh exposure time ( 7) in hours at 190 °C and in days at 160, 130,100 °C were not significantly different. The crystalline reference was untreated cloth, and the amorphous or least crystalline reference was a sample heated at 200 °C for 14 days. The 112 samples representing seven exposure times at each temperature for the four conditions were of intermediate crystallinity. By using this system, measurement of the crystallinity index did not reveal differences among samples that could be used to show changes in structural order with aging. 

Vulcanization rate was determined by a Monsanto Rheometer. The Monsanto Oscillating Dii Rheometer is designed to measure the ccanplete curing characteristics of a single rubber specimen, heated and maintained utder continuous pressure during vulcanization. Sinusoidal oscillation of a conical dirir, embedded in the vul-canizable mix confined in a heated square carity, exerte a riiear strain on the speci-... 

The introduction of specimen heating stages, together with a satisfactory method of compensating for thermal drift. 

FIGURE 4.19 SQWVs for paraffin-impregnated graphite electrodes modified with indigo (1% w/w) plus palygorskite specimen heated at 180°C for 24 h in a furnace, in contact with 0.10 M solutions of (a) Hex NPFj, (b) Bu NPFj, and Et iNGIO, in MeCN. Potential step increment, 4 mV square-wave amplitude, 25 mV frequency, 10 Hz. 

Figure 1. DSC curve of urethane reaction formulation (extended), 18 mg specimen heated at 10°C/min in nitrogen.

For specimens containing 0-35-mol. % Cr203 the compositions of the 77-oxide phase, calculated from the line positions, are also plotted in Fig. 2 and compared with those for specimens heated in H2 by drawing part of... 

Gamma irradiation (Co , total dose 5.7 X lO r) of a sample of nickel sulfate previously heated at 150° improves its acidic property to values nearly equivalent to those of a specimen heat-treated at 350°... 

Figure 8.12 Optical micrographs showing a comparison of nickel specimens heated 24 h at 1000 °C in a sealed quartz tube which contained Na2S04 in an AI2O3 crucible. The nickel specimens did not touch the Na2S04. (a) The quartz tube was evacuated and sealed. A layer of nickel sulphide (arrows) has formed on the metal beneath a dense continuous layer of NiO. The nickel sulphide has been etched electrolytically with NaNOs. (b) The qnartz tnbe was backfilled with oxygen to give a pressure of 0.9 atm at 1000 °C. A dense layer of NiO has been formed. No evidence of sulphide formation was observed.

Fig. 8. 16 The morphology of cracks (a) cracks induced by hydrogen charging for 1 h at the current density of 200 mA/cm (b) specimens heat treated at 600 °C for 10 h (c) specimens heat treated at 800 °C for 10 h (d) specimens heat treated at 1000 °C for 6 h (e) specimens heat treated at 1000 °C for 10 h (f) specimens cyclic heat treated at 1000 °C for 10 h [74],...

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