Results 31 to 40 of about 60,794 (221)
Acoustic absorption of hemp-lime construction [PDF]
Construction and Building Materials, 2016 Abstract Hemp-lime concrete is a sustainable alternative to standard wall construction materials. It boasts excellent hygrothermal properties in part deriving from its porous structure. This paper investigates the acoustic properties of hemp-lime concrete, using binders developed from hydrated lime and pozzolans as well as hydraulic and cementicious ...
Kinnane, Oliver +4 more
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Non-Hermitian Acoustic Metamaterials: the role of Exceptional Points in sound absorption [PDF]
Phys. Rev. B 95, 144303 (2017), 2016 Effective non-Hermitian Hamiltonians are obtained to describe coherent perfect absorbing and lasing boundary conditions. PT -symmetry of the Hamiltonians enables to design configurations which perfectly absorb at multiple frequencies. Broadened and flat perfect absorption is predicted at the exceptional point of PT -symmetry breaking while, for a ...
arxiv +1 more source
Anisotropic Charge Carrier and Coherent Acoustic Phonon Dynamics of Black Phosphorus Studied by Transient Absorption Microscopy [PDF]
Journal of Physical Chemistry C, 2019, 2019 Due to its corrugated hexagonal lattice structure, Black phosphorus (BP) has unique anisotropic physical properties, which provides an additional freedom for designing devices. Many body interactions, including interactions with phonon, is crucial for heat dissipation and charge carrier mobility in device.
arxiv +1 more source
Acoustic absorption of solid foams with thin membranes [PDF]
Applied Physics Letters, 2018 We measured the acoustic absorption, in the 0.5–6 kHz frequency range, of polyurethane foams with mean pore diameters between 0.6 and 3.2 mm. Two types of foams were investigated: classical open-cell ones versus membrane foams, in which thin polyurethane membranes were preserved during solidification.
Gaulon, Camille +8 more
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Subwavelength total acoustic absorption with degenerate resonators [PDF]
Applied Physics Letters, 2015 We report the experimental realization of perfect sound absorption by sub-wavelength monopole and dipole resonators that exhibit degenerate resonant frequencies. This is achieved through the destructive interference of two resonators' transmission responses, while the matching of their averaged impedances to that of air implies no backscattering ...
Min Yang +5 more
openaire +5 more sources
Ultrabroadband sound control with deep-subwavelength plasmacoustic metalayers
Nature Communications, 2023 Controlling audible sound requires inherently broadband and subwavelength acoustic solutions, which are to date, crucially missing. This includes current noise absorption methods, such as porous materials or acoustic resonators, which are typically ...
Stanislav Sergeev +2 more
doaj +1 more source
Acoustic Coatings—A Discreet Way to Control Acoustic Environment
Frontiers in Built Environment, 2021 Acoustic comfort is directly related to enhanced well-being and performance of people. A typical challenge faced by architects and acousticians is to achieve adequate acoustics while maintaining the aesthetics of the space and reducing the visual aspects
Jose Cucharero +5 more
doaj +1 more source
Far infrared absorption by acoustic phonons in titanium dioxide nanopowders [PDF]
Journal of Nanoelectronics and Optoelectronics, vol. 1, no. 1,
pages 92-98, 2006, 2006 We report spectral features of far infrared electromagnetic radiation absorption in anatase TiO2 nanopowders which we attribute to absorption by acoustic phonon modes of nanoparticles. The frequency of peak excess absorption above the background level corresponds to the predicted frequency of the dipolar acoustic phonon from continuum elastic theory ...
arxiv +1 more source
Journal of Natural FibersThis study investigates the synthesis and characterization of composite materials, pigeon pea stem, and cotton fibers blended in different ratios such as 100/0, 70/30, 60/40, 50/50, 30/70, and 0/100.
Ariharasudhan Subramanian +6 more
doaj +1 more source
Development of non-woven from recycled fabric selvedge wastes for functional sound absorption
International Journal of Sustainable Engineering, 2022 Reasons for recycling of waste include conservation of resources, reduction in the need for landfills, paying associated tipping fees and provision of low-cost raw materials for products.
Temesggen Feleke Fera +2 more
doaj +1 more source