We solve the transport equations of the electrons and phonons to understand the thermoelectric behaviour of the technologically important half-Heusler alloys MNiSn (M: Ti, Zr, Hf). Doping is simulated within the rigid band approximation. We clarify the origin of the electron dominated thermoelectric response and determine the carrier concentrations with maximal figures of merit. The phonon mean free path is studied to calculate the grain size below which grain refinement methods can enforce ballistic heat conduction to enhance the figure of merit.
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http://dx.doi.org/10.1039/c6cp01786j | DOI Listing |
Sci Adv
January 2025
Key Laboratory of Automobile Materials (Jilin University), Ministry of Education, Department of Materials Science and Engineering, Jilin University, Changchun 130022, China.
Vacancies are crucial for the radiation resistance, strength, and ductility of high-entropy alloys (HEAs). However, complex electronic interactions resulting from chemical disorder prohibit the quantification of vacancy formation energy () and migration barriers (). Herein, we propose an electronic descriptor χ (electronegativity χ and valence-electron number ) to quantify the bonding strength of constituents on the basis of the tight-binding model, which allows us to build analytical models to achieve the site-to-site quantification of and .
View Article and Find Full Text PDFJ Mol Model
January 2025
Department of Theoretical Chemistry, Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387, Krakow, Poland.
Context: The analysis of the changes in the electronic structure along intrinsic reaction coordinate (IRC) paths for model reactions: (i) ethylene + butadiene cycloaddition, (ii) prototype SN2 reaction Cl + CH3Cl, (iii) HCN/CNH isomerization assisted by water, (iv) CO + HF → C(O)HF was performed, in terms of changes in the deformation density (Δr) and the deformation of MEP (ΔMEP). The main goal was to further examine the utility of the ΔMEP as a descriptor of chemical bonding, and to compare the pictures resulting from Δr and ΔMEP. Both approaches clearly show that the main changes in the electronic structure occur in the TS region.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
The University of Sydney, Sydney, NSW, Australia.
Background: SMOC1 has recently emerged as one of the most significant and consistent new biomarkers of early Alzheimer's disease (AD). SMOC1 is one of the earliest changing proteins in AD, with SMOC1 cerebrospinal fluid levels increasing 29 years before symptom onset in autosomal dominant AD. Despite this clear association with disease, very little is known about the role of SMOC1 in AD or its function in the brain.
View Article and Find Full Text PDFNanoscale
January 2025
Department of Materials Science and Engineering, Chair for Surface Science and Corrosion (WW4-LKO), Friedrich-Alexander-Universität Erlangen-Nürnberg, Martensstraße 7, 91058 Erlangen, Germany.
The photocatalytic degradation of unwanted organic species has been investigated for decades using modified and non-modified titania nanostructures. In the present study, we investigate the co-catalytic effect of single atoms (SAs) of Pt and Pt nanoparticles on titania substrates on the degradation of the two typical photodegradation model pollutants: Acid Orange 7 (AO7) and Rhodamine B (RhB). For this, we use highly defined sputter deposited anatase layers and load them with Pt SAs at different loading densities or alternatively with Pt nanoparticles.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Chemistry, University of Massachusetts Boston, 100 Morrissey Blvd, Boston, MA, 02125, USA.
Oxidative stress, associated with excessive production of reactive oxygen and nitrogen species (ROS, RNS), contributes to the development and progression of many ailments, such as aging, cardiovascular diseases, Alzheimer's disease, Parkinson's disease, diabetes, cancer, preeclampsia or multiple sclerosis. While phenols and polyphenols are the most studied antioxidants structurally similar compounds such as anilines or thiophenols are sporadically analyzed despite their radical scavenging potential. This work assesses the impact of structural features of phenols and thiophenols on their antioxidant activity.
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