The thermodynamic temperature of the point of inflection of the melting transition of Re-C, Pt-C and Co-C eutectics has been determined to be 2747.84 ± 0.35 K, 2011.43 ± 0.18 K and 1597.39 ± 0.13 K, respectively, and the thermodynamic temperature of the freezing transition of Cu has been determined to be 1357.80 ± 0.08 K, where the ± symbol represents 95% coverage. These results are the best consensus estimates obtained from measurements made using various spectroradiometric primary thermometry techniques by nine different national metrology institutes. The good agreement between the institutes suggests that spectroradiometric thermometry techniques are sufficiently mature (at least in those institutes) to allow the direct realization of thermodynamic temperature above 1234 K (rather than the use of a temperature scale) and that metal-carbon eutectics can be used as high-temperature fixed points for thermodynamic temperature dissemination. The results directly support the developing mise en pratique for the definition of the kelvin to include direct measurement of thermodynamic temperature.
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http://dx.doi.org/10.1098/rsta.2015.0044 | DOI Listing |
Plant Foods Hum Nutr
January 2025
Instituto de Ciencia y Tecnología de Alimentos Córdoba (ICYTAC) - CONICET-UNC, Av. Juan Filloy S/N, Ciudad Universitaria, Córdoba, Argentina.
The focus of this work was to evaluate the differences between the thermal and mechanical effects generated by ultrasound waves on the properties of corn starch, which facilitate the subsequent enzymatic hydrolysis for the generation of porous starches. The results showed that both the thermal and mechanical effects have the capacity to disorganize/alter the structure of starch, impacting on its properties. Characteristics such as particle size, pasting and thermal properties (peak viscosity 1400-1800 cp.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
Center for Satellite Application on Environment, Ministry of Ecology and Environment, Beijing 100094, China.
The edge structures of carbonaceous materials exhibit temperature-dependent behavior on the atomic scale, with variations in the relative ratios of zigzag, reconstructed 5-7 zigzag (ZZ57), and armchair edges observed at different temperatures. Nevertheless, the mechanisms underlying the interconversion of these edge structures and the influence of the surrounding metals remain unclear. This study investigates the reconstruction and reversible transformation processes of ZZ57 edge structures in carbon materials and examines the effects of different metal atoms (Na, K, and Ca) by using density functional theory.
View Article and Find Full Text PDFAdv Mater
January 2025
Beijing Key Laboratory of Environmental Science and Engineering, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, 100081, China.
The safety of the P2-type layered transition metal oxides (P2-NaTMO), a promising cathode material for sodium-ion batteries (SIBs), is a prerequisite for grid-scale energy storage systems. However, previous thermal runaway studies mainly focused on morphological changes resulting from gas production detection and thermogravimetric analysis, while the structural transition and chemical reactions underlying these processes are still unclear. Herein, a comprehensive methodology to unveil an interplay mechanism among phase structures, interfacial microcrack, and thermal stability of the charged P2-NaNiMnO (NNMO) and the P2-NaNiLiMnO (NNMO-Li) at elevated temperatures is established.
View Article and Find Full Text PDFAdv Mater
January 2025
Key Laboratory of Precision and Intelligent Chemistry, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, National Synchrotron Radiation Laboratory, Center for Micro and Nanoscale Research and Fabrication, Institute of Advanced Technology, University of Science and Technology of China, Hefei, 230026, P. R. China.
Breaking the thermal, mechanical and lightweight performance limit of aerogels has pivotal significance on thermal protection, new energy utilization, high-temperature catalysis, structural engineering, and physics, but is severely limited by the serious discrete characteristics between grain boundary and nano-units interfaces. Herein, a thermodynamically driven surface reaction and confined crystallization process is reported to synthesize a centimeter-scale supercontinuous ZrO nanolayer on ZrO-SiO fiber aerogel surface, which significantly improved its thermal and mechanical properties with density almost unchanged (≈26 mg cm). Systematic structure analysis confirms that the supercontinuous layer achieves a close connection between grains and fibers through Zr─O─Si bonds.
View Article and Find Full Text PDFChemistryOpen
January 2025
Central Department of Physics, Tribhuvan University, Kathmandu, Nepal.
Thermodynamic properties of amino acids explore the ideas about the energetic contribution in biomolecular interfaces. In our work, we have estimated the solvation free energy of leucine and isoleucine peptides with the variation of chain length or residues of different monomer units (n=1, 2, 4, 8 & 16) using molecular dynamic simulation. We modeled our system using OPLS-AA force field and TIP3P water model at 310 K temperature.
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