Thesis (Ph. D.)--University of Wisconsin--Madison, 1932. / Typescript. With this is bound: An isothermal calorimeter for slow reactions / by E.D. Coon and Farrington Daniels. Reprinted from Journal of physical chemistry, vol. XXXVII, no. 1 (Jan. 1933), 12 p. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1957. / Typescript. Abstracted in Dissertation abstracts, v. 17 (1957) no. 7, p. 1478-1479. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 55, 117-119).

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A fluidless adiabatic calorimeter was constructed and was used to measure the specific heats of manganese-aluminum-carbon and manganese-zinc-carbon alloys from -150° to 150°C. In an adiabatic calorimeter, the temperature of a shield surrounding the calorimeter vessel is kept at approximately the same temperature as that of the vessel, so that the thermal leakage between the two is reduced to a negligible quantity. Thus the ordinary rating period, in which the thermal leakage modulus is calculated, can be eliminated. Since leakage modulus variations are reduced by the adiabatic method, it can be used for large temperature rises, resulting in fast and accurate measurements. The aneroid (fluidless) adiabatic calorimeter eliminates stirring and evaporation errors, and makes possible measurements at extreme temperatures. The calorimeter consisted of a cylindrical silver-plated copper vessel surrounded by an electrically heated adiabatic shield and an evacuated outer case. A platinum resistance thermometer-heater was used to supply heat to the calorimeter vessel and to measure the vessel temperature. The heat input and the thermometer resistance were measured by using a potentiometer in conjunction with standard resistances. The thermometer was calibrated by measuring its resistance at -183, -40, 0, and 100°C. The calorimeter was calibrated from -150 to 150°C. The accuracy of the calorimeter was approximately 0.5%, the main error arising from the method of measuring the temperature of the calorimeter vessel. The specific heat curves of the single phase magnetic alloys Mn₃AIC and Mn₃ZnC were measured. A second order specific heat anomaly was found, as expected, for the ferromagnetic alloy Mn₃AlC at its Curie point, -10°C. Although the anomaly was close to the theoretical shape, dropping to zero over only a 10°C range at the Curie point, its maximum height was less than saturation magnetization measurements would indicate. The alloy Mn₃ZnC showed second order specific heat anomalies at -35°C, and at 65°C. This double specific heat anomaly indicates, in agreement with neutron diffraction results, a complex magnetic behaviour for the alloy. Although the high temperature Curie point anomaly did not have a sharp peak, the low temperature anomaly's shape approached that of the theoretical Weiss curve. / Applied Science, Faculty of / Materials Engineering, Department of / Graduate

The current thesis examined local and whole-body heat loss responses during heat stress at rest, exercise and/or pharmacological stimuli as a function of increasing age. The first study examined the effects of age on whole-body heat loss and heat storage during passive exposure to conditions representative of the upper temperature extremes in Canada. The results demonstrate that the cumulative change in body heat content after 2 h of rest was significantly greater in older adults in a hot-dry (older: 212±25; young: 131±27 kJ, P=0.018) and hot-humid (older: 426±37; young: 317±45 kJ, P=0.037) condition. The second study evaluated the maximal capacity of whole-body evaporative heat loss as a function of age and aerobic fitness. The findings demonstrate that whole-body evaporative heat loss was significantly lower in middle-aged untrained (Ex2: 426±34; Ex3:497±17 W) and older (Ex2: 424±38; Ex3: 485±44 W) compared to young (Ex2: 472±42; Ex3: 558±51 W) and middle-aged trained (Ex2: 474±21; Ex3: 552±23 W) males at the end of the last two exercise bouts (P<0.05). The third study assessed the maximal capacity of whole-body evaporative heat loss in females and found that whole-body evaporative heat loss was significantly lower (P=0.002) in the older (Ex2: 343±39 W; Ex3: 389±29 W) compared to the young (Ex2: 383±34 W; Ex3: 437±36 W) females at the end of the second and third exercise-induced heat loads of 325 and 400 W, while no differences were observed during recovery (P=0.693). The fourth study examined nitric oxide-dependent sweating during exercise/rest cycles in young and older adults. We showed that nitric oxide-dependent sweating during short bouts of exercise in the heat is observed in young males, but not in older adults. The fifth study examined: 1) the extent to which peripheral factors (i.e., sweat gland and skin vasodilatory function) contribute to the postexercise suppression of heat loss; and 2) whether age-related differences exist in the mechanisms modulating postexercise heat loss. The findings demonstrate that there were no differences in sweat rate between the no exercise resting condition and a postexercise condition at either an acetylcholine (ACh) or methacholine (MCh) site for the young (ACh: P=0.992 and MCh: P=0.710) or older (ACh: P=0.775 and MCh: P=0.738) adults. However, older adults had a lower sweating response for both the no exercise resting condition (ACh: P=0.049 and MCh: P=0.006) and postexercise condition (ACh: P=0.050 and MCh: P=0.029) compared to their younger counterparts. Taken together, the current thesis shows true age-related impairments in the ability to dissipate heat exist during both a passive and exercise-induced heat stress over a certain heat load threshold. Specifically, older adults have an impaired ability to dissipate heat compared to young adults during rest in hot-dry and hot-humid conditions. Additionally, middle-aged untrained and older adults have a reduced capacity to dissipate heat at an exercise-induced heat load of ≥400 W for males and ≥325 W for females, which becomes more pronounced at as the level of heat load increases. However, the age-related impairment in heat loss can be attenuated by maintaining a high level of aerobic fitness. Furthermore, age-related impairments in sweating may be associated with age-related reductions in nitric oxide-mediated sweating. However, there does not appear to be age-related differences in the modulation of heat loss postexercise.

The heat of neutralization, ΔH_-N, of perchloric acid with sodium hydroxide has been determined at 10 and 40° in a low ionic strength, μ, region using a nonisothermal, constant-temperature-environment solution calorimeter. Correction of the data to infinite dilution by extrapolation of a plot of ΔH_-N vs μ^0.5 gives values at zero ionic strength for the heat of ionization of water of 14.216 and 12.695 kcal/mole, respectively, at 10 and 40° . The data are correlated with those of earlier workers to give an equation allowing the calculation of the heat of ionization of water at zero ionic strength over the temperature range 0-55°. The heat of reaction of tris(hydroxymethyl)aminomethane (THAM) with 0.1 M hydrochloric acid solution has been determined calorimetrically at 10, 25, and 40° C. The experimental conditions suggested by the Standards Committee of the U.S. Calorimetry Conference were followed. ΔH values of -7.644 ± 0.014, -7.104 ± 0.008, and -6.555 ± 0.012 kcal/mole at 10, 25, and 40° C, respectively, are reported. Results of the study are compared with those of other workers, and THAM is recommended for use as an interlaboratory comparison standard for solution calorimetry.

ΔH° values are reported for the formation of Fe(CN)_6^4- (-85.77 ± 0.09 kcal/mole), Fe(CN)_6^3- (-70.14 ± 0.10 kcal/mole), Mn(CN)_6^4- (-36.76 ± 0.07 kcal/mole), Co(CN)_5^3- (-61.96 ± 0.15 kcal/mole), Ni(CN)_4^2- (-43.26 ± 0.08 kcal/mole), Zn(CN)_4^2- (-28.53 ± 0.10 kcal/mole), Cu(CN)_n^1-n (n = 2,3,4 - 29.1 ± 0.10, - 40.3 ± 0.10, and - 50.5 ± 0.01 kcal/mole respectively), PdBr_4^2- (-13.11 ± 0.06 kcal/mole), PdCl_4^2- (-5.50 ± 0.05 kcal/mole), Pd(CN)_4^2- (-92.14 ± 0.10 kcal/mole), Cd(CN)_4^2- (-28.50 ± 0.10 kcal/mole), Ag(CN)_2^- (-32.88 + 0.08 kcal/mole), and Ag(CN)_3^2- (-33.45 ± 0.10 kcal/mole) from their respective constituent ions in aqueous solution. A method is discussed for estimating the ligand field stabilization energy for low spin octahedral complexes from the measured ΔH° value. A comparison of the ΔH values for the formation PdX_4^2- (X = CN, Cl, Br) from their respective aqueous ions show that the ΔH value for Pd(CN)_4^2- is 75 kcal/mole more exothermic than the ΔH values for the formation of PdX_4^2- (X = Cl,Br). This large difference in ΔH values is discussed in terms of different bonding properties of the CN^-, Cl^- and Br^- ions. Evidence is presented which suggests that the nonstepwise formation of some cyano complexes results from ligand field effects. The ΔH° values for the formation of soluble Turnbull's and Prussian blue were measured. The resulting values are -15.08 ± 0.05 and +0.65 ± 0.01 kcal/mole, respectively. Soluble Prussian and Turnbull's blue were found to be thermochemically equivalent and to be noncolloidal in aqueous solution. The Co^2+ -CN^- system was investigated in dilute aqueous solution. The heat of interaction of Co^2+ and CN^- was studied as a function of the CN^-/Co^2+ ratio and the H^+ concentration. An enthalpy change of -30 kcal/mole results when the Co(CN)_5^3- ion reacts with one equivalent of H^+. A kinetic study was made of the decay of Co(CN)_5^3- under controlled pH conditions and as a function of Co(CN)_5^3- concentration. The following reactions were postulated as steps in the decay of Co(CN)_5^3- to form Co(CN)_5 H_2O^2- and H_2. Co(CN)_5^3- + H^+ = HCo(CN)_5^2- (1) 2HCo(CN)_5^2- = [ HCo(CN)_5 ]_2^4- (2) [ HCo(CN)_5 ]_2^4- = 2Co(CN)_5^2- + H_2 (3)

During recent years an increasing number of technical firms and manufacturers have begun to specify heat flux, energy input per unit area per unit time, as a testing and designing criteria. This change in the boundary condition (to heat flux from temperature excess or others) evolved from the idea that each material has a characteristic burning temperature. Therefore, the rate of ablation or burning depends mainly upon the rate of energy input into the specimen, and not its temperature. Thus, the need for a flux measuring device became more acute.

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