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Abstract  

Thermal investigations using infrared (IR) thermometry and false colour thermography were carried out on flowering plants in the Botanical Garden of Berlin and in a private garden. Special interest went to phototropic plants that orient their blossoms towards a light source (mainly the sun) and within this group to solar trackers (heliotropism) that follow the path of the sun during the day. Best known among the latter is the sunflower. Bowl shaped flowers comparable to satellite disks focus the solar radiation effectively on their centre, resulting in a warming of the female organs at that point. Temperature differences above ambient can be as high as 10.7 K with a mean value of 6.0 K. Pollinating insects were often observed sun-basking in the bowls or on the flower disks attracted by energetic rewards in form of nectar and heat.

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Thermometry, Enthalpimetry

Thermometric and enthalpimetric analysis

Journal of Thermal Analysis and Calorimetry
Author: L. S. Bark
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Abstract  

Thermal investigations were performed on a colony of the Colombian stingless bee Trigona (Frieseomelitta) nigra paupera by means of thermometry and direct calorimetry. A nest with about 2000 individuals was transferred to a twin calorimeter, where the bees continued their normal life and development. Two camping boxes (‘Poor Man’s Calorimeter, PMC’) with Peltier elements as cooling systems were used as a differential system. Each box had a volume of 8 L and a sensitivity of 19.2 mV W−1. The colony was monitored calorimetrically and thermometrically with resistors distributed in the nest. Signals were recorded continuously by a four-channel data logger.

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Abstract  

A brief outline of the history of development of the temperature concept in physics is given. Simultaneously, some persisting imperfections in the conceptual basis of classical thermodynamics closely related to the first and the second law of thermodynamics are discussed.

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Abstract  

Simultaneous calorimetric and potentiometric/thermometric measurements were performed on three uncatalyzed bromate oscillators (UBOs) showing distinct temporal structures. The following UBOs were chosen: a) the gallic acid (3,4,5-trihydroxy benzoic acid)—bromate; b) the 1-hydroxy-4-[(1-hydroxy-2-methylamino)ethyl] benzene (HME)—bromate; and c) the 1,4-cyclohexanedione (CHD)—bromate system. Their oscillating reactions were monitored by an isoperibolic batch calorimeter of the Calvet-type at 20°C and with a quasi-adiabatic Dewar setup at room temperature, and in addition by platinum/calomel potentiometry and thermometry. Shape of the calorimetric curves, number and duration of the oscillations and their frequencies varied considerably between these three UBOs. The underlying chemical reaction schemes are discussed in connection with the energetic background.

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Abstract

A detailed petrographic and mineral-chemical study on metapelites from the Meliatic accretionary wedge complex (Bôrka Nappe, Western Carpathians, Slovak Republic) reveals the HP character of the samples using quantitative phase diagrams contoured with mineral composition, H2O mode isopleths and garnet-phengite thermometry. The presented PT pseudosections prove that small-scale differences in bulk rock composition are responsible for the variations in the mineral assemblages formed at the same PT conditions. The peak conditions indicate blueschist facies metamorphism (520–620 °C, 11–14 kbar) and are correlated with the 150–165 Ma subduction of the Mesozoic Meliata Oceanic branch of the Neotethys. Continuous decrease of P and T from peak conditions enabled the metapelitic rocks to preserve their HP assemblages. The presented HP conditions and retrograde PT path with decreasing P and T are characteristic of subduction zone tectonic settings which are in agreement with most of the geodynamic and tectonic reconstructions for the area.

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Experimental progress in adiabatic, cryogenic calorimetry is tersely reviewed and contrasted with other techniques for heat capacity determinations in this temperature region—including DSC. Trends and prognostications of important developmente including scaling down sample size and use of adjuvant thermometry.

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Prof. Dr. GNTER SAUERBREY, 1933–2003 Gnter Sauerbrey died on 15 May, 2003, a few days after his 70th birthday. For 24 years he was responsible for the Laboratory of Medical Techniques and Dosimetry of the Physikalisch-Technische Bundesanstalt, Berlin and he also taught at Universities. His important invention was the use of a quartz oscillator as a mass sensor, the quartz crystal microbalance (QCM), which he developed in his research for his doctoral thesis at the Technical University at Berlin. He described that method in two often cited papers: Phys. Verhandl., 1957. 8: p. 193 and Z. Physik, 1959. 155: p. 206–222. With the QCM, Sauerbrey introduced a new class of mass measuring devices: inertial balances. The Sauerbrey equations are the basis of all vibrational weighing systems. His experiments on QCM allowed the extension of Einstein’s equivalence principle from uniform fields to time-dependent fields. Further work was on radiometry, thermometry, medical measuring techniques, high-temperature and vacuum physics. Gnter Sauerbrey participated at several Conferences on Vacuum Microbalance Techniques and discussed at these events, in particular, applications of the QCM. Requiescat in pace. Erich Robens, Vasile Mecea

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Thermal tests in antiquity and in the Middle Ages. Blowpipe tests. Measuring temperature and the development of thermometers. Latent heat. The nature of heat. Amount of heat. Differential thermal analysis. Differential scanning calorimetry. Heat treatment of precipitates. Thermobalances. Thermoanalytical methods associated with determination of evolved gas. Thermometry, enthalpimetry.

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), Yangling, Shaanxi, P. R. China, 26–29 October 2003. p. 14. (Abstract in J. of Experimental Bot. Suppl. 1 :54.) Anda, A., Ligetvári, F. 1991. Infrared Thermometry in Scheduling Irrigation. ICID Bulletin, Spec. Tech

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