Experimental equalization of a one‐dimensional sound field using energy density and a parametric equalizer

2004 ◽  
Vol 116 (4) ◽  
pp. 2591-2591
Author(s):  
Micah Shepherd ◽  
Xi Chen ◽  
Timothy Leishman ◽  
Scott Sommerfeldt
Keyword(s):  
Energy Density ◽  
Sound Field ◽  
One Dimensional

Equalization of a one‐dimensional sound field using acoustic energy density

2003 ◽  
Vol 114 (4) ◽  
pp. 2460-2460
Author(s):  
Xi Chen ◽  
Timothy Leishman ◽  
Scott Sommerfeldt
Keyword(s):  
Energy Density ◽  
Sound Field ◽  
Acoustic Energy ◽  
One Dimensional ◽  
Acoustic Energy Density

scholarly journals An Experimental Study of the Performance of a Crossed Rib Diffuser in Room Acoustic Control

2021 ◽  
Vol 11 (9) ◽  
pp. 3781
Author(s):  
Takumi Yoshida ◽  
Yasutaka Ueda ◽  
Norimasa Mori ◽  
Yumi Matano
Keyword(s):  
Sound Field ◽  
Wide Band ◽  
Scattering Coefficient ◽  
Scaled Model ◽  
One Dimensional ◽  
Broadband Absorption ◽  
Acoustic Control ◽  
Absorbing Layer ◽  
Speech Clarity ◽  
Reverberation Parameters

This paper presents a crossed rib diffuser (CRD) as an effective tool for room acoustic control. We performed an experimental investigation of its effectiveness using a specimen manufactured for this trial. The CRD is constructed by overlapping two one-dimensional (1D) periodic rib diffusers with different specifications so that they are crossed at non-right angles. The CRD achieves a higher scattering coefficient than 1D periodic rib diffusers in a wide band while maintaining the simple and friendly design of 1D periodic rib diffusers applicable to various architectural spaces. Moreover, inserting an absorbing layer between upper and lower ribs of the CRD, (CRD-A) yields a high broadband absorption coefficient. We first evaluated the random-incidence scattering coefficient of CRD using a 1/5 scaled model in comparison with those of 1D periodic diffusers assessed with a numerical method. Then, absorption coefficients for the CRD and the CRD-A were measured using a reverberation room. Subsequently, an experiment on a small meeting room with a 1D periodic rib diffuser, the CRD and the CRD-A was conducted to present performance of the CRD in room acoustic control. Impulse response measurements and evaluations of reverberation parameters (T20 and EDT) and speech clarity (D50) were conducted. Additionally, we present differences in structure of reflected sounds found for the flat wall, the CRD and the CRD-A visually using a four-channel sound field microphone.

High-Energy-Density Polymer Nanocomposites Composed of Newly Structured One-Dimensional BaTiO3@Al2O3 Nanofibers

2017 ◽  
Vol 9 (4) ◽  
pp. 4024-4033 ◽  
Author(s):  
Zhongbin Pan ◽  
Lingmin Yao ◽  
Jiwei Zhai ◽  
Dezhou Fu ◽  
Bo Shen ◽  
...  
Keyword(s):  
Energy Density ◽  
Polymer Nanocomposites ◽  
High Energy ◽  
High Energy Density ◽  
One Dimensional

scholarly journals On the Definition of Energy Flux in One-Dimensional Chains of Particles

Entropy ◽  
2019 ◽  
Vol 21 (11) ◽  
pp. 1036
Author(s):  
Paolo De Gregorio
Keyword(s):  
Energy Density ◽  
Integral Operator ◽  
Energy Flux ◽  
Ad Hoc ◽  
The Other ◽  
Energy Density Distribution ◽  
One Dimensional ◽  
Integral Quantity ◽  
Definition Of ◽  
Local Quantity

We review two well-known definitions present in the literature, which are used to define the heat or energy flux in one dimensional chains. One definition equates the energy variation per particle to a discretized flux difference, which we here show it also corresponds to the flux of energy in the zero wavenumber limit in Fourier space, concurrently providing a general formula valid for all wavelengths. The other relies somewhat elaborately on a definition of the flux, which is a function of every coordinate in the line. We try to shed further light on their significance by introducing a novel integral operator, acting over movable boundaries represented by the neighboring particles’ positions, or some combinations thereof. By specializing to the case of chains with the particles’ order conserved, we show that the first definition corresponds to applying the differential continuity-equation operator after the application of the integral operator. Conversely, the second definition corresponds to applying the introduced integral operator to the energy flux. It is, therefore, an integral quantity and not a local quantity. More worryingly, it does not satisfy in any obvious way an equation of continuity. We show that in stationary states, the first definition is resilient to several formally legitimate modifications of the (models of) energy density distribution, while the second is not. On the other hand, it seems peculiar that this integral definition appears to capture a transport contribution, which may be called of convective nature, which is altogether missed by the former definition. In an attempt to connect the dots, we propose that the locally integrated flux divided by the inter-particle distance is a good measure of the energy flux. We show that the proposition can be explicitly constructed analytically by an ad hoc modification of the chosen model for the energy density.

Topologically distributed one-dimensional TiO2 nanofillers maximize the dielectric energy density in a P(VDF-HFP) nanocomposite

2020 ◽  
Vol 8 (35) ◽  
pp. 18244-18253
Author(s):  
Xiaoru Liu ◽  
Penghao Hu ◽  
Jinyao Yu ◽  
Mingzhi Fan ◽  
Xumin Ji ◽  
...  
Keyword(s):  
Energy Density ◽  
One Dimensional

The dielectric energy density of a P(VDF-HFP) nanocomposite is greatly enhanced via the use of one-dimensional TiO2 nanofillers with a topological distribution.

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