A method for estimating acoustic absorption in porous materials is presented in which the thermal and viscous boundary layers are modeled through boundary conditions to the Helmholtz equation for the acoustic pressure. The method is proposed for rigid-framed porous materials in which vibration of the frame is negligible compared to pressure fluctuations in air. The method reduces computation times by 2 orders of magnitude compared to a full thermoviscous acoustic solver. Furthermore, the method is shown to be highly accurate over geometrical features and frequencies of interest as long as thermal and viscous boundary layers do not overlap and the effects of the sharp changes in curvature are negligible. The method is demonstrated for a periodic sound absorber from the literature as well as a sound absorber with a randomly graded microstructure.
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http://dx.doi.org/10.1121/10.0001959 | DOI Listing |
Phys Rev Lett
December 2024
University of New Brunswick, UNB MRI Centre, Department of Physics, Fredericton, New Brunswick, E3B 5A3, Canada.
We observe divergent temperature-dependent magnetic resonance relaxation behaviors across various brine-saturated porous materials. The paramagnetic and diamagnetic nature of the samples underlies these divergent behaviors. The temperature-dependent trends of the longitudinal T_{1} and transverse T_{2} relaxation times are systematically explained via distinct relaxation-diffusion regimes of Brownstein-Tarr theory.
View Article and Find Full Text PDFMikrochim Acta
January 2025
Indian Institute of Technology (BHU), Varanasi, 221005, India.
In the modern age, half of the population is facing various chronic illnesses due to glucose maintenance in the body, major causes of fatality and inefficiency. The early identification of glucose plays a crucial role in medical treatment and the food industry, particularly in diabetes diagnosis. In the past few years, non-enzymatic electrochemical glucose sensors have received a lot of interest for their ability to identify glucose levels accurately.
View Article and Find Full Text PDFLangmuir
January 2025
Prof. Rashidi Laboratory of Organometallic Chemistry & Material Chemistry, Department of Chemistry, College of Science, Shiraz University, Shiraz, 7194684795, Iran.
In this study, a Pd nanoparticles@hydrogen-bonded organic framework (Pd NPs@HOF) thin film was fabricated at the toluene-water interface. The HOF was formed through the interaction of trimesic acid (TMA) and melamine (Mel) in the water phase, while Pd(0) was produced from the reduction of [PdCl(cod)] in the organic phase. The as-synthesized Pd NPs@HOF thin film was demonstrated to be an effective catalyst for the selective reduction of -nitrophenol and -nitrophenol to -aminophenol and -aminophenol.
View Article and Find Full Text PDFChemSusChem
January 2025
Indian Institute of Technology Ropar, Chemistry, Nangal Road, 140001, Rupnagar, INDIA.
Photocatalytic conversion of CO2 into value-added chemicals offers a propitious alternative to traditional thermal methods, contributing to environmental remediation and energy sustainability. In this respect, covalent organic frameworks (COFs), are crystalline porous materials showcasing remarkable efficacy in CO2 fixation facilitated by visible light owing to their excellent photochemical properties. Herein, we employed Lewis acidic Zn(II) anchored pyrene-based COF (Zn(II)@Pybp-COF) to facilitate the photocatalytic CO2 utilization and transformation to 2-oxazolidinones.
View Article and Find Full Text PDFIn Vitro Model
February 2024
Faculty of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-Cho, Koganei, Tokyo 184-8588 Japan.
Unlabelled: Engineered three-dimensional (3D) tissue culture platforms are useful for reproducing and elucidating complex in vivo biological phenomena. Spheroids, 3D aggregates of living cells, are produced based on physicochemical or microfabrication technologies and are commonly used even in cancer pathology research. However, conventional methods have difficulties in constructing 3D structures depending on the cell types, and require specialized techniques/lab know-how to reproducibly control the spheroid size and shape.
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