Medindo a temperatura de um gás no regime de micro-Kelvin

O desenvolvimento científico nos permite trabalhar hoje com gases em temperaturas muito inferiores aos 10-6 K. Estes gases, uma vez obtidos por técnicas de resfriamento óptico, precisam ser caracterizados com relaçãao às suas propriedades termodinâmicas. a a medida da temperatura. Dentre tais propriedades está a medida da temperatura. Neste trabalho mostramos de forma tutorial como são medidas tais baixas temperaturas, através de técnicas de tempo de voo. Tais técnicas combinam conhecimento básico de mecânica, termodinâmica dentre outros tópicos convencionalmente estudados nos cursos básicos de física.

Temperature Effects on Suction Measurement Using the Filter Paper Technique

This paper presents the results of an experimental study of thermal effects on filter paper calibration curves used to obtain the soil suction. When the temperature is significantly different from ambient values, it is essential to consider the influence of temperature on the filter paper calibration curves to obtain a reliable soil suction measurement. The calibration curve of Whatman No. 42 filter paper was determined at 10 degrees C, 25 degrees C, and 50 degrees C using the vapor equilibrium technique with sodium chloride solutions at different concentrations and the axis translation technique. The experimental results showed a major influence of temperature on the filter paper calibration curves. Using the obtained experimental data a calibration equation was proposed, taking into account the effect of temperature. The obtained calibration curves were then used to determine the soil water retention curve of kaolin clay, which showed lower retention capacity at higher temperatures.

Measurement and model calculation of the temperature dependence of ligand-to-metal energy transfer rates in lanthanide complexes

Temperature dependent transient curves of excited levels of a model Eu3+ complex have been measured for the first time. A coincidence between the temperature dependent rise time of the 5D0 emitting level and decay time of the 5D1 excited level in the [Eu(tta)3(H2O)2] complex has been found, which unambiguously proves the T1→5D1→5D0 sensitization pathway. A theoretical approach for the temperature dependent energy transfer rates has been successfully applied to the rationalization of the experimental data.

Body temperature, Aldrete-Kroulik index, and patient discharge from the Post-Anesthetic Recovery Unit

Patient discharge from post-anesthetic recovery (PAR) depends, among other factors, on normothermia and the patient's score on the Aldrete-Kroulik index. The objective of this study was to verify the relationship between the Aldrete-Kroulik index and body temperature in patients. This study was performed at the University of Sao Paulo University Hospital. Convenience sampling was used, and the sample consisted of 60 patients of ages between 18 and 60 years who underwent general anesthesia. The patients' body temperature was obtained by tympanic measurement, and the Aldrete-Kroulik index was measured on admission and at discharge from post-anesthetic recovery. The data were processed using SPSS, considering a significance level of 5%, and the Spearman and Wilcoxon tests were applied. In conclusion, no significant correlation was found between the two parameters for discharge.