Acoustic transmission loss in Hilbert fractal metamaterials.

Sci Rep

Bristol Composite Institute (BCI), School of Civil, Aerospace and Mechanical Engineering (CAME), University of Bristol, Bristol, UK.

Published: November 2023

Acoustic metamaterials are increasingly being considered as a viable technology for sound insulation. Fractal patterns constitute a potentially groundbreaking architecture for acoustic metamaterials. We describe in this work the behaviour of the transmission loss of Hilbert fractal metamaterials used for sound control purposes. The transmission loss of 3D printed metamaterials with Hilbert fractal patterns related to configurations from the zeroth to the fourth order is investigated here using impedance tube tests and Finite Element models. We evaluate, in particular, the impact of the equivalent porosity and the relative size of the cavity of the fractal pattern versus the overall dimensions of the metamaterial unit. We also provide an analytical formulation that relates the acoustic cavity resonances in the fractal patterns and the frequencies associated with the maxima of the transmission losses, providing opportunities to tune the sound insulation properties through control of the fractal architecture.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10625595PMC
http://dx.doi.org/10.1038/s41598-023-43646-1DOI Listing

Publication Analysis

Top Keywords

transmission loss
12
hilbert fractal
12
fractal patterns
12
loss hilbert
8
fractal metamaterials
8
acoustic metamaterials
8
sound insulation
8
fractal
7
metamaterials
5
acoustic
4

Similar Publications

Pile driving for offshore wind turbines typically generates high sound levels in the water column. Bubble curtains are frequently employed to protect marine fauna. This study aims to investigate the effect of a bubble curtain on the generated sound wave field.

View Article and Find Full Text PDF

Magnetoliposomes containing magnetite, soy lecithin, stigmasterol, and beta-sitosterol of the mean size minor than 160 nm were obtained by a scalable and green process using autoclave and sonication without organic solvents. The formation, size of the liposome, linkage, and encapsulation of the magnetite were evaluated by Cryo-TEM. The stability of magnetoliposomes after storage for 6 months at 4 °C was improved by liposome size, the ability of soy lecithin to preserve the magnetite phase against oxidation, pH, polydispersity index, and zeta potential.

View Article and Find Full Text PDF

Detection of Tilapia parvovirus in farm-reared tilapia in India and its isolation using fish cell lines.

In Vitro Cell Dev Biol Anim

January 2025

Aquatic Animal Health Laboratory, PG & Research Department of Zoology, C. Abdul Hakeem College, (Affiliated to Thiruvalluvar University), Melvisharam, Tamil Nadu, India.

Tilapia parvovirus (TiPV) is an emerging viral pathogen and responsible for severe economic loss in tilapia culture production. Lethargic, cutaneous haemorrhages; ocular lesions; discolouration of gill and cloudy eye and exophthalmia are common symptoms of TiPV. The TiPV-suspected tilapia fish were collected from grow-out ponds situated in different parts of Tamil Nadu, India, and screened for TiPV by PCR.

View Article and Find Full Text PDF

Thermochromic smart windows have been widely developed for building energy saving. However, most smart windows suffer from limited energy-saving performance, fixed phase transition temperature, and are not suitable for the temperature regulation needs of different application scenarios. Herein, a unique self-adaptive thermochromic hydrogel (HBPEC-PNA) with self-moisture-absorbing performance is reported that assembles solar energy cooling and evaporative heat dissipation.

View Article and Find Full Text PDF

Early ultrastructural damage in retina and optic nerve following intraocular pressure elevation.

Vision Res

January 2025

Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.

Elevated intraocular pressure (IOP) is a significant risk factor for glaucoma, causing structural and functional damage to the eye. Increased IOP compromises the metabolic and structural integrity of retinal ganglion cell (RGC) axons, leading to progressive degeneration and influencing the ocular immune response. This study investigated early cellular and molecular changes in the retina and optic nerve (ON) following ocular hypertension (OHT).

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!