Wave-based modeling of sound insulation of a double layer finite panel with different infilling materials between two reverberant rooms

2018 ◽  
Vol 144 (3) ◽  
pp. 1847-1847
Author(s):  
Fangliang Chen ◽  
Yihe Huang ◽  
Tejav DeGanyar
Keyword(s):  
Double Layer ◽  
Sound Insulation

Broadband diffuse field sound insulation of double layer metamaterial plates lined with porous material

2021 ◽  
Vol 119 (8) ◽  
pp. 084103
Author(s):  
Shuaixing Wang ◽  
Yong Xiao ◽  
Jiajia Guo ◽  
Hao Zhang ◽  
Jihong Wen
Keyword(s):  
Porous Material ◽  
Double Layer ◽  
Sound Insulation ◽  
Field Sound

Design of the Sound Insulation Chamber for Stored Grain Insect Sound Detection

2012 ◽  
Vol 220-223 ◽  
pp. 1598-1601 ◽  
Author(s):  
Sen Lin Geng ◽  
Fang Ju Li
Keyword(s):  
Double Layer ◽  
Ambient Noise ◽  
Outer Wall ◽  
Wall Material ◽  
Sound Insulation ◽  
Stored Grain ◽  
Layer Spacing ◽  
Average Spacing ◽  
Sound Detection ◽  
Absorbing Material

A six cubic meter sound insulation chamber is designed based on the principle of double-layer wall sound insulating and porous absorption with the characteristics of stored grain insect action sound. With 3 mm thick plywood as wall material, double - layer spacing 0.08 m, the outer wall being bored, each aperture 1mm, average spacing 1.5 cm, and the hard sound-absorbing material being filled in the two layers, a quasi - double layer perforated structure is built. The ambient noise is uniformly insulated between 125Hz and 2000Hz, and the average sound insulation is about 22dB, and it meets requirements of stored grain insect action sound for the spectrum and SPL. The result shows that the sound insulation chamber has the advantages of small size, economy, and good sound insulation effects.

Study on sound insulation performance of double-layer perforated panel under normal incidence waves

2021 ◽  
Vol 174 ◽  
pp. 107785
Author(s):  
Zhongxu Kang ◽  
Ruixiang Song ◽  
Huijuan Zhang ◽  
Qiang Liu
Keyword(s):  
Double Layer ◽  
Normal Incidence ◽  
Sound Insulation ◽  
Insulation Performance

The Feasibility of Rock Wool Waste Utilisation in a Double-Layer Concrete Brick for Acoustic: A Conceptual Review

2020 ◽  
Vol 17 (2) ◽  
pp. 635-644
Author(s):  
Nur Zulzika Mohammad ◽  
Yap Zhen Shyong ◽  
Zaiton Haron ◽  
Mohammad Ismail ◽  
Azman Mohamed ◽  
...  
Keyword(s):  
Double Layer ◽  
Noise Pollution ◽  
High Energy ◽  
Sound Insulation ◽  
Insulation Material ◽  
Sound Barrier ◽  
Solid Media ◽  
Concrete Layer ◽  
Aerated Concrete ◽  
Rock Wool

Denser population in a city leads to a serious noise pollution problem. In order to control the ambient noise effectively, a sound insulation brick is desired. However, conventional bricks have poor sound barrier system and is made from unsustainable materials that consume high energy. Hence, this paper introduces a feasibility study on rock wool waste utilisation in a double-layer concrete brick (a combination of aerated concrete and solid concrete) as a potential technique to improve the sound barrier system in brick walls. Currently, rock wool waste is one of the synthetic wastes, which are massively dumped into the landfill by the industry or building demolition castoffs every year. However, rock wool waste has the potential to be recycled and reused as a sound insulation material because it still has the fibrous structural characteristic. Aerated concrete is generally known as an acoustic material; hence, this paper reviews on the implementation of rock wool waste in the aerated concrete layer to improve noise absorption performance. The optimum sound absorption and the thickness of aerated concrete were subsequently integrated with the solid media to transmit sound and indirectly improve the overall brick strength to form a double-layer concrete brick and facilitate the invention of sustainable bricks.

scholarly journals SETTING UP A PROBLEM OF AIR-BORNE SOUND IN-SULATION CALCULATION FOR DOUBLE LAYER MASSIVE ENCLOSURES ON THE BASE OF THE MODELS WITH THE CONCENTRATED PARAMETERS

2020 ◽  
Vol 16 (4) ◽  
pp. 111-120
Author(s):  
Arkadiy Zakharov ◽  
Ivan Saltikov
Keyword(s):  
Double Layer ◽  
Sound Propagation ◽  
Graph Drawing ◽  
Practical Interest ◽  
Single Layer ◽  
Mass Action ◽  
Sound Insulation ◽  
Mass Action Law ◽  
The One ◽  
Oscillation Movement

The calculation methods on the base of the concentrated parameters models, which were formed in the XX century, allowed to get simple and theoretically consistent solutions for the problems of one-layered building partitions sound insulation finding. The sound insulation estimation for the double-layered massive building partitions also is of scientific and practical interest, as double layer partitions are the particular case of the single layer enclosure's application. The concept of concentrated parameters includes the concentrated and the reduced masses, as well as the concentrated elasticity. The criteria for the object application as a specified kind of the concentrated parameters in the acoustical problems is the presence or the absence of the oscillation movement in it. The three calculation models with the application of the concentrated (discreet) parameters that to define the sound insulation of the massive double layer enclosures are given. The equations for sound insulation computation for one layer partition are represented. They were derived on the base of momentum law and energy conservation formulas under the continuity of energy flow conditions at the interface of different media. The three main paths of sound propagation from the room with the air-borne noise to the isolated room are shown. The two frequency range are separated on the way of the direct sound propagation: at the first, the surface density of the one of two layers and the air elasticity in the inter-layer gap influence on isolation; at the second one, the predominant role belongs to the summarized insulation by the "Mass Action Law" of the two layers. The indirect way's insulation is taken in account through the additional sound insulation graph drawing. The compound insulation curve is defined by the ways, where the sound energy transmittance is maximal at the standard frequency spectrum. The method of sound insulation calculation for the double layer partitions on the base of the concentrated parameters model application is revealed. As an example, the calculation of a prefabricated double layer inter-flat wall in the panel building was performed.

Sound reduction index prediction of double-layer gypsum panels through the transfer matrix method

2020 ◽  
pp. 1351010X2092103
Author(s):  
Nicola Granzotto ◽  
Chiara Scrosati ◽  
Fabio Scamoni ◽  
Edoardo A Piana
Keyword(s):  
Transfer Matrix ◽  
Double Layer ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Resonance Effect ◽  
Single Layer ◽  
Air Gap ◽  
Cavity Resonance ◽  
Sound Insulation ◽  
Acoustic Insulation

Gypsum board walls are widely used in today’s buildings. A possible way to considerably increase the sound insulation performances of such lightweight walls is to apply double-layer gypsum panels screwed together. Being the boards separated by a thin air gap, there is no shift of the critical frequency from the single-layer case. Moreover, it is possible to obtain an improvement of the sound insulation performances provided by the additional mass given by the double layer. The thin air layer is, however, responsible for a loss of acoustic performance due to the cavity resonance effect in the frequency range between 800 and 1600 Hz. In this article, the increase in the acoustic insulation achieved through the use of coupled gypsum boards is studied and a modelling technique based on the transfer matrix method is used to simulate the acoustic behaviour of the resulting structure; in particular, the thin air layer between the coupled boards is modelled. The simulations are compared with laboratory measurements carried out according to the international standard series ISO 10140. The transfer matrix approach is found to be suitable to describe the problem, provided that a modified model for the air gap between the boards is applied.

Cracking at the fold in double layer coated paper: the influence of latex and starch composition

TAPPI Journal ◽  
2019 ◽  
Vol 18 (2) ◽  
pp. 93-99
Author(s):  
SEYYED MOHAMMAD HASHEMI NAJAFI ◽  
DOUGLAS BOUSFIELD, ◽  
MEHDI TAJVIDI
Keyword(s):  
Mechanical Properties ◽  
Double Layer ◽  
Starch Content ◽  
Single Layer ◽  
Double Layers ◽  
Coated Paper ◽  
Coated Papers ◽  
Coating Layers ◽  
Scanned Images ◽  
Packaging Paper

Cracking at the fold of publication and packaging paper grades is a serious problem that can lead to rejection of product. Recent work has revealed some basic mechanisms and the influence of various parameters on the extent of crack area, but no studies are reported using coating layers with known mechanical properties, especially for double-coated systems. In this study, coating layers with different and known mechanical properties were used to characterize crack formation during folding. The coating formulations were applied on two different basis weight papers, and the coated papers were folded. The binder systems in these formulations were different combinations of a styrene-butadiene latex and mixtures of latex and starch for two different pigment volume concentrations (PVC). Both types of papers were coated with single and double layers. The folded area was scanned with a high-resolution scanner while the samples were kept at their folded angle. The scanned images were analyzed within a constant area. The crack areas were reported for different types of papers, binder system and PVC values. As PVC, starch content, and paper basis weight increased, the crack area increased. Double layer coated papers with high PVC and high starch content at the top layer had more cracks in comparison with a single layer coated paper, but when the PVC of the top layer was low, cracking area decreased. No measurable cracking was observed when the top layer was formulated with a 100% latex layer.

A Survey on Crypto-Steganographic Schemes and A Use Case in Healthcare System

2019 ◽  
Vol 1 (2) ◽  
pp. 25-33
Author(s):  
Mei Ling Phang ◽  
Swee Huay Heng
Keyword(s):  
Social Networking ◽  
Information Sharing ◽  
Healthcare System ◽  
Double Layer ◽  
21St Century ◽  
Electronic Devices ◽  
Third Party ◽  
Use Case ◽  
Comparison Analysis ◽  
Information Assets

Information sharing has become prevalent due to the expansion of social networking in this 21st century. However, electronic devices are vulnerable to various kinds of attacks. Information might be disclosed, modified and accessed by an unauthorised third party which consequently leads to the breach of confidentiality, integrity and availability of the information. Therefore, it is of utmost importance to employ the technology of cryptography and steganography to protect information assets. Cryptography and steganography have weaknesses when they are working alone. Therefore, crypto-steganography, the combination of cryptography and steganography are introduced to overcome the weaknesses in order to provide a double layer of security and protection. This paper provides a general overview of steganography and cryptography as well as a comparison analysis of different crypto-steganographic schemes. A secure crypto-steganographic system for healthcare is then developed with the implementation and integration of the secure crypto-steganographic scheme proposed by Juneja and Sandhu. This healthcare system enables users to store and deliver message in a more secure way while achieving the main goals of both cryptography and steganography.

Electrode for Electric Double Layer Capacitor Made of Carbonized and Activated Cotton Cloth

2014 ◽  
Vol 134 (5) ◽  
pp. 360-361
Author(s):  
Masumi Fukuma ◽  
Takayuki Uchida ◽  
Yukito Fukushima ◽  
Jinichi Ogawa ◽  
Katsumi Yoshino
Keyword(s):  
Double Layer ◽  
Electric Double Layer ◽  
Cotton Cloth ◽  
Electric Double Layer Capacitor ◽  
Double Layer Capacitor
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