Otto Zinke

Professor Emeritus of Physics

Otto Henry Zinke received the A.B, A.M., and Ph.D. degrees at Washington University, St. Louis. As an undergraduate, Zinke developed one of the first automated gamma-ray spectrometers. As a graduate student at the same institution, he produced the first complete Auger-electron spectrum. At the University of Arkansas, he brought into his physics laboratory a technique for simultaneously measuring resistance and permeability without contact to the sample which he had developed in his home laboratory. With Paul B. Jacovelli, he showed the technique was capable of measuring temperature changes in metal samples of the order of 0.00001 K degrees . Through the use of this technique he, Jacovelli, and Chester E. Canada were able to show that the emissivity of foils carrying transient heat differed from the emissivity of foils with static temperature distributions. This was followed by a series of experiments measuring the transfer of transient heat to surrounding gas. While teaching a course in physical techniques in archaeology (outside of his normal teaching load), he was struck during a lecture with the fact that the alpha-recoil technique could be applied to determine the time of firing of aboriginal pottery and worked with archaeologists E.G Garrison, C.R. McGimsey III, of the University of Arkansas and E. Haury of the University of Arizona to certify the technique in a blind test on Hohokam pottery. The Thomson Effect is a thermocouple effect and had been the center of some controversy in the 19th century. Further, the Onsager formulation of non-equilibrium thermodynamics produced the coupled-flow equations which were modified by H. Callen to predict thermocouple behaviors among which is the Thomson Effect. The thermocouple system seems to be the principal experimental evidence for the theory of non-equilibrium thermodynamics. Since the technique used on transient heat seemed to lend itself to very accurate measurements of Thomson Coefficients and since the data on Thomson Coefficients seemed to be in some disarray, Canada (1) carried out Thomson measurements. This section will be referenced since the manuscript which described the results was refused for publication (with appeal) by the Physical Review with the phrase, "The Thomson Effect is old and well known." In temperature regions far from ambient, Canada's results obtained in vacuo agreed with those obtained by others. Near ambient temperature, there was upsweep in the data. That ambient temperature was a variable was quickly determined by the way the results varied in the laboratory where the ambient temperature was essentially unregulated. New apparatus was built by Norris (2) that could produce an identifiable ambient temperature stabilized over short times to 0.01 degrees. Norris was able to sweep the temperature of Thomson measurements both above and below the ambient temperature and found that the Thomson Coefficient did not exist at the ambient temperature. That was rather odd since that is the only point where the current density vector is either parallel or anti-parallel to the temperature gradient and that is where the maximum of the Thomson Effect should occur. James B. Sawyer compiled a complete description (3) of all Thomson measurements. Similarities to Norris's data were seen where most previous experimenters had made measurements approaching the ambient temperature. Sawyer then proceeded to show that Thomson's relation between Thomson Coefficients and the second derivative of the Seebeck emf did not seem to hold for most measurements. At this point, Jacovelli and Zinke constructed a thermocouple with continuous iron and copper wires broken in the cold junction. One set of wires between the hot and cold junction was inside a heat-conducting copper tube joining the junctions and the other set was in ambient room temperature. The latter set of wires produced the normal copper-iron emf curve as a function of temperature. However, if either wire of a copper-iron couple was in the heat-conducting tube, the emf curve previously seen was radically changed. Finally, the Benedicks emfs of the iron-iron thermocouple rose to over 600 microVolts, orders of magnitude above any Benedicks emf ever seen. The general conclusion reached by Zinke's group was that the Onsager-Callen formulation needs to be re-examined. A summary of these results have been published (4). Through the use of a time-of-flight technique developed in Zinke's laboratory, his students C.K. Manka, D.P. Ross, J.R. Crawford, and D.W. Collier, analyzed the methods of production of flow velocities and temperatures of pulsed plasmas in the kilo-and mega-degree regions. As emeritus professor, Zinke worked with William Schmidt, Chair of the Department of Mechanical Engineering and published a number of papers on nondestructive evaluation problems including detection and characterization of fatigue-induced cracks, and detection of hidden corrosion, grain-structure changes, and hardening of metals. He developed a novel technique for measuring strains in metals and a nondestructive method for measuring residual stress in steels which is more convenient to use than the cumbersome X-ray method. This technique can be used to measure changes in stress direction of in-situ steel structures. He is currently working on detection of stress changes produced by trucks on steel and concrete highway bridges and stress shifts in the gusset plates of steel bridges. While, Zinke published on subjects above, he also published on subjects as diverse as Bose-Einstein condensation, disappearance of the monopole term of the magnetic vector potential, the theory of AC magnetic-flux circuits (where he introduced the term complex reluctance into the literature) and a nanocentimeter transducer. He spent several years on a Ford Foundation Grant as the energy/environmental adviser to the governor of Arkansas in the early seventies and a summer as a Senior Science Advisor in the U.S. Senate. He served as chair of the University of Arkansas Chapter, the State of Arkansas Conference, and the Southwestern Conference of the American Association of University Professors. He was a founding member of the Arkansas Affiliate of the American Civil Liberties Union and served as the first secretary and the second chair of that organization. He served on the national board of the ACLU. He was a leader in the fight for free speech on the University of Arkansas campus in the early sixties. In the sixties and seventies he helped integrate the public facilities of Fayetteville, Arkansas. (1) C.E. Canada, Measurement of Thomson Coefficients, Ph.D. dissertation, University of Arkansas, 1969. (2) R.C. Norris, Effect of Thermal Radiation of Measurement of a Thomson Coefficient. Master of Science Thesis, University of Arkansas, 1970. (3) J.B. Sawyer, A Review of Thomson Effect Measurement Techniques, Master of Science Thesis, 1975. (4) Evidence of an Anomalous Thomson Effect, Thermoelectricity in Metallic Conductors, edited by F.J. Blatt and P.A. Schneider, Plenum Press, New York, 1978.