The static dielectric properties of Stockmayer fluids are investigated in the hyperspherical geometry, S(3). Different methods of obtaining the static dielectric constant ε(r) are compared. Tested methods include the evaluation of the Kirkwood factor, fluctuations of the total dipole moment, and a two-center potential correlation formula to obtain the dielectric constant through effective interactions. With no coupling to the "surrounding," the different methods give consistent estimates of the dielectric constant. Adding a coupling to the surrounding gives large size dependencies and the two-center potential correlation formula breaks down. For low dipole moments, there is a good agreement in the dielectric constant with previous studies.
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http://dx.doi.org/10.1063/1.3495975 | DOI Listing |
J Magn Reson Imaging
January 2025
Department of Radiology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, Jiangsu, China.
Background: At high magnetic fields, degraded image quality due to dielectric artifacts and elevated specific absorption rate (SAR) are two technical challenges in fetal MRI.
Purpose: To assess the potential of high dielectric constant (HDC) pad in increasing image quality and decreasing SAR for 3 T fetal MRI.
Study Type: Prospective.
Angew Chem Int Ed Engl
January 2025
Northwestern Polytechnical University, School of Chemistry and Chemical Engineering, CHINA.
The increasing power and integration of electronic devices have intensified serious heat accumulation, driving the demand for higher intrinsic thermal conductivity in thermal interface materials, such as polydimethylsiloxane (PDMS). Grafting mesogens onto PDMS can enhance its intrinsic thermal conductivity. However, the high stability of the PDMS chain limits the grafting density of mesogens, restricting the improvement in thermal conductivity.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
School of Materials Science and Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, P. R. China.
First-principles calculations, particularly density functional theory (DFT) combined with D3 dispersion correction (DFT+D3), have proven to be valuable tools in simulating the adsorption of lead ions on TiCO surfaces. However, conventional theoretical models assume electrically neutral systems under vacuum conditions, neglecting the solvent environment and electrode potential's crucial effects. This study employed an implicit solvent model, treating the solvent as a continuous and homogeneous medium to capture the influence of different solvents by varying their dielectric constants.
View Article and Find Full Text PDFACS Omega
January 2025
Laboratory of Theoretical Chemistry, Theoretical and Structural Physical Chemistry Unit, Namur Institute of Structured Matter (NISM), University of Namur, rue de Bruxelles, 61, B-5000 Namur, Belgium.
Density functional theory (DFT) has been enacted to study the Diels-Alder reaction between 2,5-dimethylfuran (2,5-DMF), a direct product of biomass transformation, and acrolein and to analyze its thermodynamics, kinetics, and mechanism when catalyzed by a Lewis acid (LA), in comparison to the uncatalyzed reaction. The uncatalyzed reaction occurs via a typical one-step asynchronous process, corresponding to a normal electron demand (NED) mechanism, where acrolein is an electrophile whereas 2,5-DMF is a nucleophile. The small endo selectivity in solvents of low dielectric constants is replaced by a small exo selectivity in solvents with larger dielectric constants, such as DMSO.
View Article and Find Full Text PDFJ Food Sci
January 2025
Department of Physics, the Institute of Science, Dr. Homi Bhabha State University, Mumbai, India.
The adulteration of honey is a globally growing issue due to its medicinal benefits and health-promoting properties. This problem primarily involves the addition of sugars and other substances. To address these concerns, a comparative study was conducted to investigate the dielectric and spectroscopic properties of pure, sugar solution added honey, and commercially available honey.
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