Ultrasonic relaxation spectra were determined for lower vicinal and terminal alkanediols at ambient pressure and a temperature of 298.15 K. The ultrasound absorption measurements were made by means of the standard pulse technique for 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,4-butanediol, 2,3-butanediol, and 1,5-pentanediol within the frequency range of 5-300 or 10-300 MHz. Relaxation processes were observed for all compounds except 1,2-ethanediol. The relaxation regions were dependent on both the carbon chain length and the position of hydroxyl groups. In addition, the terminal diols showed lower absorption than the adequate vicinal diols did. The results are discussed in terms of molecular structure and molecular interactions, as well as compared with the behavior of adequate lower 1-alkanols. A comparison with classical absorption is also made. The results are discussed in term of shear viscosity relaxation.
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http://dx.doi.org/10.1021/jp502700k | DOI Listing |
Quant Imaging Med Surg
January 2025
Department of Ultrasonic Diagnosis, The First Hospital of China Medical University, Shenyang, China.
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View Article and Find Full Text PDFCurr Top Med Chem
January 2025
Department of Pharmaceutical Chemistry, JSS College of Pharmacy, JSS Academy of Higher Education & Research (JSS AHER), Mysuru, Karnataka, India.
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View Article and Find Full Text PDFUltrasonics
December 2024
Department of Information Engineering and Computer Science, University of Trento, Italy.
Background: Shear wave elastography (SWE) is a technique that quantifies tissue stiffness by assessing the speed of shear waves propagating after being excited by acoustic radiation force. SWE allows the quantification of elastic tissue properties and serves as an adjunct to conventional ultrasound techniques, aiding in tissue characterization. To capture this transient propagation of the shear wave, the ultrasound device must be able to reach very high frame rates.
View Article and Find Full Text PDFNano Lett
December 2024
Department of Oral Implantology, School and Hospital of Stomatology, Jilin University, Changchun 130021, China.
J Chem Phys
November 2024
Institut für Physik, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str. 7, 06120 Halle (Saale), Germany.
Recent 15N R1ρ-relaxation studies have shown that proteins in the solid state undergo slow, low amplitude global motion in the sub-millisecond time range. This range is at the edge of the time window for R1ρ experiments and, therefore, the motional parameters obtained by this method are not precise or reliable. In this paper, we present a 2H stimulated echo study of this type of molecular dynamics.
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