We present a simplified, rapid, and accurate method for the measurement of the thermoelectric Thomson coefficient by the dynamical heating of a suspended wire by an alternating current. By applying a temperature gradient across the wire, we find that the response at the second harmonic of the excitation frequency is directly proportional to the Thomson coefficient. The absolute thermoelectric coefficient of a single material can therefore be extracted with high precision by using a phase sensitive detector. We test our method on platinum and nickel wires and develop both analytical and numerical models to determine the leading sources of error.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1063/1.5055826 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Electron temperature measurement from neutral atomic tungsten emission line ratio.
Rev Sci Instrum
January 2025
University of Dayton Research Institute, Dayton, Ohio 45469, USA.
A method to determine electron temperature within a plasma by the spectral analysis of atomic tungsten emission has been explored. The technique was applied to a post-discharge region immediately following a high voltage nanosecond pulsed discharge in air with tungsten electrodes. Atomic tungsten lines are readily observed in the weak emission spectrum within the post-discharge region for many microseconds.
View Article and Find Full Text PDFInvestigation of tritium content in wild plants growing in an area with an underground source of tritium.
J Environ Radioact
December 2024
FSBI All-Russian Research Institute of Radiology and Agroecology of the NRC, Kurchatov Institute. Obninsk, Kaluga Region Russian Federation, Russia.
Within the framework of the presented work, the results of large-scale studies of the content of TFWT in wild plants growing in an area with an underground source of tritium are presented. Various types of plants were studied: herbaceous, shrubby, woody. The concentration of TFWT in various vegetative organs of the same plants was analyzed separately.
View Article and Find Full Text PDFCalculation of thermodynamic properties of helium using path integral Monte Carlo simulations in the NpT ensemble and ab initio potentials.
J Chem Phys
December 2024
Institut für Thermodynamik, Helmut-Schmidt-Universität/Universität der Bundeswehr Hamburg, Holstenhofweg 85, 22043 Hamburg, Germany.
We apply the methodology of Lustig, with which rigorous expressions for all thermodynamic properties can be derived in any statistical ensemble, to derive expressions for the calculation of thermodynamic properties in the path integral formulation of the quantum-mechanical isobaric-isothermal (NpT) ensemble. With the derived expressions, thermodynamic properties such as the density, speed of sound, or Joule-Thomson coefficient can be calculated in path integral Monte Carlo simulations, fully incorporating quantum effects without uncontrolled approximations within the well-known isomorphism between the quantum-mechanical partition function and a classical system of ring polymers. The derived expressions are verified by simulations of supercritical helium above the vapor-liquid critical point at selected state points using recent highly accurate ab initio potentials for pairwise and nonadditive three-body interactions.
View Article and Find Full Text PDFIdentifying opportunities to reduce imaging overuse in hospitalized children.
J Hosp Med
December 2024
Division of Hospital Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.
Article Synopsis
- Radiologic imaging is often used in children's hospitals to assist with diagnoses, but variations in how it's performed can lead to unnecessary costs and risks.
- A study analyzed inpatient pediatric conditions across 50 hospitals from 2017 to 2019, focusing on those with high imaging prevalence and costs, and found that conditions like pectus excavatum and scoliosis had the highest imaging rates.
- The findings indicated significant variations in imaging-related costs among hospitals, highlighting the need for improved guidelines to reduce overuse and improve care in pediatric imaging.
Validation of galvanomagnetic and thermomagnetic transport measurements using Standard Reference Material 3451.
Rev Sci Instrum
November 2024
Department of Mechanical and Materials Engineering, University of Cincinnati, Cincinnati, Ohio 45221, USA.
In the "method of four coefficients," electrical resistivity (ρ), Seebeck coefficient (S), Hall coefficient (RH), and Nernst coefficient (Q) of a material are measured and typically fit or modeled with theoretical expressions based on Boltzmann transport theory to glean experimental insights into features of electronic structure and/or charge carrier scattering mechanisms in materials. Although well-defined and readily available reference materials exist for validating measurements of ρ and S, none currently exists for RH or Q. We show that measurements of all four transport coefficients-ρ, S, RH, and Q-can be validated using a single reference sample, namely, the low-temperature Seebeck coefficient Standard Reference Material® (SRM) 3451 (composition Bi2Te3+x) available from the National Institute for Standards and Technology (NIST) without the need for inter-laboratory sample exchange.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!