Thermal data

The most important reactivity effect arises from changes in the average coolant density including the contribution of vapor voids. The moderator 

Another important property of the reactor is its reactivity behavior with changes of the thermal power output. In Table VI the essential parameters are listed for a few power levels (calculated values). 

Power (%) Inlet temp. (°C) Average void fraction (%) AAr.f, without Doppler effect 

Since with constant system pressure in a self-pressurized reactor the outlet enthalpy remains constant, power changes must result in deviations of the inlet temperature. The void fraction reacts to the power level because all radial deviations from the average enthalpy rise due to the power profile are approximately proportional to the power level. 

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Table 1. Thermal Data for Changes of State of Titanium Compounds...

Table 9.11 Thermal Data for the Streams In the Pulping Case Study ...

Bench Scale ERS Sizing Tools— Acquisition of Thermal Data— Apparatus Design and Sample Thermal Data for 5 Systems, DIERS/AIChE, 1986, 159 pages. 

Data on thermal performance are not readily available on all heat exchangers because of the proprietary nature of the machines. To exemplify typical thermal data, heat transfer can best be described by a Dittus-Boelter type equation ... 

Training is critical with any of the imaging systems. The variables that can destroy the accuracy and repeatability of thermal data must be compensated for each time infrared data is acquired. In addition, interpretation of infrared data requires extensive training and experience. 

Table 21.18 Structures, thermal data, and molar volumes of metal oxides and hydroxides, and of some double oxides ...

The contribution of this lack of regularity to the entropy of ice is thus R In 3/2 = 0.805 E. U. The observed entropy discrepancy of ice at low temperatures is 0.87 E. U., obtained by subtracting the entropy difference of ice at very low temperatures and water vapor at standard conditions, for which the value 44.23 E. U. has been calculated from thermal data by Giauque and Ashley,7 from the spectroscopic value 45.101 E. U. for the entropy of water vapor given by Gordon.8 The agreement in the experimental and theoretical entropy values provides strong support of the postulated structure of ice.9... 

The DSC and TGA plots of the oxidized polymer (VIII) showed that the Tm is 130°C and the weight loss of 20% and 80% was observed at 455°C and 600°C, respectively, compared to 400° and 482°C for the original polymer VII indicating the oxidized polymer was more stable to heat. This observation was consistent with the chemical structure of the oxidized polymer, which consisted of a repeating aromatic pyrrole structure and, therefore, should be more thermodynamically stable. The thermal data of the polymers are tabulated in Table II. 

Ruzicka, K., Majer, V. (1994) Simultaneous treatment of vapor pressures and related thermal data between the triple and normal boiling temperatures for ra-alkanes C5 - C20. J. Phys. Chem. Ref. Data 23, 1-39. 

TABLE 6.1. Thermal Data for Ternary Single-Source Precursors... 

In order to analyse the packed bed process, it is necessary to consider both heat transfer from the solid to the gas and reaction heat which may be transmitted to the gas. The composition of the gas, and hence its physical properties, are determined by the rate of reduction, which in turn depends on each layer of the packed bed, and on the degree of reduction which has already occurred. In the reduction of haematite, there are three stages in the reduction, corresponding to the formation of Fe304 and FeO before the metal is formed. The thermal data for the reduction processes can be approximated by the respective heats of reduction by H2 and CO gases. Taking 1000°C as a typical mean temperature, the mean value for the heats of reaction per 2 gram-atom of iron are... 

The equipment is quite adequate for screening purposes. In its simplest form (i.e., a glass tube in an oven), it is a relatively low cost technique that can be assembled with standard laboratory equipment. However, the simple test set-up provides no quantitative thermal data for scale-up purposes, but only T0 values. The more advanced instruments like the SEDEX and SIKAREX, which are also isoperibolic calorimetry equipment, acquire specific thermal stability data that can be used for scale-up. Furthermore, the small autoclave tests provide gas evolution data. 

Step 1—acquisition of thermal data, e.g., the adiabatic temperature rise ATa,... 

The first five measure the activity of the solvent and the last five measure the activity of the solute. The boiling point method is generally not included in evaluations for two reasons there are little data from these measurements or the thermal data are not adequate to apply an accurate correction to obtain an activity at 298 K. 

Alloy crystal and thermal data symbols. A number of tables show, for selected alloys, the highest melting points observed in the systems considered, as well as the mechanism of formation (p = peritectic melting, syn = synthetic reaction, s.s.r. = solid-state reaction, est. = estimated melting point, etc.), the value of the Raynor Index (<1, =1 or>l). The question mark means that no reliable data are available. 

Laboratory furnaces. Several types of furnaces are used in the laboratory these are often available as commercial rigs, generally equipped with more or less sophisticated temperature measurement and control devices. As an alternative, a lab-made or commercial furnace and its temperature measuring devices may be connected to a multi-channel data acquisition/actuator/switch unit, to be programmed by a personal computer, in order to plan and carry out thermal treatments, to collect and retrieve measured thermal data, etc. 

Table 4.5. Characteristic thermal data of a microhotplate with Pt temperature sensor...

P(NH3) at 0 K can be computed from other thermal data through consideration of an appropriate Bom-Haber cycle (aU substances except NH4CI... 

Using thermal data available in this and preceding chapters, derive an expression for AG as a function of temperature for the reaction... 

We can calculate AH from thermal data alone, that is, from calorimetric measurements of enthalpies of reaction and heat capacities. It would be advantageous if we could also compute AS from thermal data alone, for then we could calculate AG or Ay without using equilibrium data. The requirement of measurements for an equilibrium state or the need for a reversible reaction thus could be avoided. The thermal-data method would be of particular advantage for reactions for which AG or AT is very large (either positive or negative) because equilibrium measurements are most difficult in these cases. 

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