scholarly journals Potensi Limbah Ampas Teh sebagai Alternatif Material Akustik Ramah Lingkungan

2021 ◽  
Vol 3 (2) ◽  
pp. 113-120
Author(s):  
Ukhti Mutia Munifatuzzahroh ◽  
Ian Yulianti ◽  
Fianti Fianti
Keyword(s):  
Noise Reduction ◽  
Sound Absorption ◽  
Environmentally Friendly ◽  
Tea Waste

The research aims to determine the potential of tea waste as an environmentally friendly alternative acoustic material. The acoustic material is made by mixing tea waste powder with fox glue and water, formed, and dried. The acoustic material was made into six samples with different compositions of tea wastes, that were 20 g, 40 g, 60 g, 80 g, 100 g, and 120 g. The value of the effectiveness of noise reduction and the coefficient of sound absorption, both were obtained the most optimum in sample 6 with a composition of 120 g, that were 10.1% and 0.07497 dB. The value of both increases with the increase of the composition of the tea wastes in the acoustic material.

scholarly journals Методы определения характеристик звукопоглощения строительных материалов и звукоизоляции конструкций (обзор)

2020 ◽  
Vol 45 (4) ◽  
Author(s):  
Keyword(s):  
Noise Reduction ◽  
Sound Absorption ◽  
Building Materials ◽  
Developed Countries ◽  
Reduction Factor ◽  
Sound Insulation ◽  
Reverberation Chamber ◽  
Normative Documents ◽  
Urban Conditions ◽  
First Time

Исследование акустических характеристик строительных материалов и конструкций необходимо для комфортной жизни людей в городских условиях. Несмотря на то что в нормативных документах развитых государств есть ряд методов их определения, единого понимания самих характеристик и путей их адекватного определения до сих пор нет. В настоящей работе мы попытались систематизировать и дать критический обзор нормативных документов, содержащих методы определения звукопоглощающих свойств материалов и звукоизоляционных характеристик конструкций. Впервые выявлены присущие разным методам закономерности определения характеристик звукопоглощения и звукоизоляции. Определены наиболее характерные показатели звукопоглощения. Произведено ранжирование по коэффициенту уменьшения шума NRC наиболее часто применяемых строительных материалов. Названы области применения рассматриваемых методик, проанализированы их преимущества и ограничения. Ключевые слова: коэффициент уменьшения шума, звукопоглотитель, импедансная труба, реверберационная камера The study of the acoustic characteristics of building materials and structures is necessary for provision of comfortable life of people in urban conditions. Despite the fact that in the normative documents of developed countries there are a number of methods for their determination, there is still no common understanding of the characteristics themselves and the ways of their adequate determination. In this work we tried to systematize and give a critical review of regulatory documents containing the methods for determining the sound-absorbing properties of materials and the sound-insulating characteristics of structures. For the first time the regularities in determination the characteristics of sound absorption and sound insulation inherent in different methods have been revealed. The most characteristic indicators of sound absorption have been determined. The ranking of the most commonly used building materials was made according to the noise reduction factor (NRC). The areas of application of the considered methods are presented, their advantages and limitations are analyzed. Keywords: noise reduction factor, sound absorber, impedance tube, reverberation chamber

Optimization of geometric parameters of the standardized multilayer microperforated panel with finite dimension

2019 ◽  
Vol 67 (3) ◽  
pp. 197-209 ◽  
Author(s):  
Xiaocui Yang ◽  
Liang Chen ◽  
Xinmin Shen ◽  
Panfeng Bai ◽  
Sandy To ◽  
...  
Keyword(s):  
Noise Reduction ◽  
Sound Absorption ◽  
Finite Dimension ◽  
Search Algorithm ◽  
Theoretical Data ◽  
Cuckoo Search ◽  
Cuckoo Search Algorithm ◽  
Spring Steel ◽  
Geometric Parameters ◽  
Optimization Simulation

Standardized multilayer microperforated panel fabricated by laser beam machining of the spring steel was proposed for noise reduction in this study. Geometric parameters of the standardized multilayer microperforated panel, which include diameter of the hole, thickness of the panel, distance between the neighbor holes, and length of the cavity, were optimized for the better sound absorption performance. Sound absorption coefficient of the standardized multilayer microperforated panel was theoretically modeled based on the Maa's theory. The optimization of geometric parameters of the standardized multilayer microperforated panel was obtained by the Cuckoo search algorithm, and the finite dimension of 30 mm was treated as the additional constraint condition. Preliminary verification of the obtained optimal parameters was conducted through the constructed finite element simulation model. Actual sound absorption coefficients of the standardized multilayer microperforated panels with layer number of 1 to 4 were measured by standing wave method, which were consistent with theoretical data and simulation data, and the corresponding average values in the frequency range of 100â–“6000 Hz were 57.45%, 70.85%, 71.99%, and 72.28%, respectively. By theoretical modeling, parameter optimization, simulation, and experimental validation, an effective method was proposed to develop practical sound absorbers, which would promote their applications in noise reduction.

Semi-active control of smart porous structure for sound absorption enhancement

2019 ◽  
Vol 30 (17) ◽  
pp. 2575-2580
Author(s):  
Bo-Seung Kim ◽  
Semin Kwon ◽  
Seongyoung Jeong ◽  
Junhong Park
Keyword(s):  
Porous Medium ◽  
Noise Reduction ◽  
Active Control ◽  
Sound Absorption ◽  
Active Noise Control ◽  
Absorption Enhancement ◽  
Reactive Material ◽  
Operation Conditions ◽  
Reducing Ability ◽  
Absorption Characteristics

For sound absorption of conventional porous materials, its noise-reducing ability in low frequencies is less than that in high frequency bands. A porous layer offers effective sound absorption when the thickness of layer is a quarter wavelength of the sound wave. Increasing the layer thickness is not an effective solution. Adjustment of rear air cavity volume for the porous medium has been used in practical applications to increase low frequency sound absorption. Noise reduction using only passive sound absorption characteristics is a challenge, especially when the operation conditions of noise source changes. In this study, we propose a smart porous material having noise reduction ability in the broad frequency band. We implement semi-active control by applying a magnetic reactive material to a porous medium. The smart foam proposed in this study reduced noise with adjustment of the magnitude and polarity of the magnetic field. Evaluation of its noise reduction performance is performed with the impedance tube method. Experiments are conducted for semi-active noise control of the proposed smart foam. The sound absorption characteristics are controlled efficiently with relatively low electric power consumption. A theoretical model to predict absorption characteristics is proposed using the transfer-matrix method, and its results show good agreement with measured behaviors.

Car's Materials Acoustic Properties Test and Analysis

2013 ◽  
Vol 785-786 ◽  
pp. 1244-1247
Author(s):  
Yan Liu ◽  
Xiao Juan Zhang ◽  
Zong Cai Liu
Keyword(s):  
Noise Reduction ◽  
High Frequency ◽  
Sound Absorption ◽  
Transmission System ◽  
Acoustic Properties ◽  
Frequency Noise ◽  
Car Industry ◽  
High Frequency Noise ◽  
Urban Construction ◽  
The Impact

With the development of the car industry, the pace of the urban construction is accelerating as well. Cars have gradually entered the ordinary family. As the car noise has a big effect on the health of the passengers, as well as on the surroundings, one of the car industry key duties is the car noise reduction. By researching the materials applied to car, this article describe that PU material could reduce the impact of the engine noise on the cab efficiently; Polypropylene needle-spun felt could reduce the noise passed by chassis; PET material's sound absorption is poor in mid bass, however in high frequency it's sound absorption is good; sound absorbing sponge can reduce the low and high frequency noise; The combine sponge can reduce the noise from the tire and transmission system ; Cotton material could absorb the high frequency noise.

Development of Natural Fibre Non-Woven Materials’ Application as Car Interiors for Noise Reduction

2011 ◽  
Vol 332-334 ◽  
pp. 1531-1534 ◽  
Author(s):  
Ming Ma ◽  
Yuan Bai ◽  
Xiao Ming Qian
Keyword(s):  
Noise Reduction ◽  
Reference Point ◽  
Sound Absorption ◽  
Noise Control ◽  
Natural Fibre ◽  
Noise Sources ◽  
Absorption Properties ◽  
Vehicle Noise ◽  
Nonwoven Materials ◽  
Potential Market

This document mainly introduces the evaluation of vehicle noise, noise sources and noise control. The development of fibers used for noise reduction materials is described as well. Besides, it analyzes the advantages and the necessities of the natural fibre nonwoven materials applied for the noise control, illustrates the present research status and the factors that introduces the sound absorption properties of the natural fibre nonwoven composites used for noise reduction. The paper also gives some reference point for advice to the development of automotive nonwoven materials. it shows that natural fibre nonwoven materials have a huge potential market and worthy for scholars to make a further study.

Considerations for the Reduction of Noise in Ship Installations of Gas Turbines

1960 ◽  
Vol 82 (3) ◽  
pp. 205-214
Author(s):  
Edward M. Herrmann
Keyword(s):  
Noise Reduction ◽  
Gas Turbines ◽  
Sound Absorption ◽  
Sound Insulation ◽  
Specific Information ◽  
Airborne Sound

General noise reduction considerations for shipboard installation of gas turbines are discussed. Specific information relating to sound-absorption materials, duct treatments, structureborne sound isolation, and airborne sound insulation is graphically presented.

An environmentally friendly batch bioadsorption study of the radionuclides 67Ga from aqueous solutions by fibrous tea waste

2010 ◽  
Vol 165 (2) ◽  
pp. 563-572 ◽  
Author(s):  
Hayrettin Eroglu ◽  
Erhan Varoglu ◽  
Sinan Yapıcı ◽  
Ali Sahın
Keyword(s):  
Aqueous Solutions ◽  
Environmentally Friendly ◽  
Tea Waste

scholarly journals Noise Reduction Effect of Porous Asphalt Pavement Based on Acoustic-Structure Coupling Model

2021 ◽  
Vol 8 (2) ◽  
pp. 97-102
Author(s):  
Jiakun Yang ◽  
Zhou Qiu ◽  
Chuanfeng Zheng
Keyword(s):  
Noise Reduction ◽  
Sound Absorption ◽  
Asphalt Pavement ◽  
Traffic Noise ◽  
Coupling Model ◽  
Comsol Multiphysics ◽  
Acoustic Structure ◽  
Porous Asphalt ◽  
Reduction Effect ◽  
Pore Depth

Nowadays, the traffic noise problem is becoming increasingly prominent. In order to study the influence of porosity and pore depth on the noise reduction performance of asphalt pavement, this paper used the software COMSOL Multiphysics to establish acoustic-structure coupling models, and simulated the sound absorption and noise reduction effect of asphalt pavement under 10%, 15%, 20%, 25%, and 30% porosity; moreover, under the condition of unchanged asphalt pavement porosity, the sound absorption and noise reduction effect of asphalt pavement under 3cm, 4cm, 5cm, 6cm, and 7cm pore depth was studied as well. The research results reveal that, with the increase of porosity and pore depth, the sound absorption and noise reduction effect of asphalt pavement gets better.

scholarly journals Crumb Rubber Effect on Acoustic Properties of Self- Consolidating Concrete

2014 ◽  
Vol 08 (2) ◽  
Keyword(s):  
Experimental Study ◽  
Noise Reduction ◽  
Sound Absorption ◽  
Crumb Rubber ◽  
The Self ◽  
Acoustic Properties ◽  
Scrap Tires ◽  
Self Consolidating Concrete ◽  
Reduction Coefficient ◽  
Environmentally Sound

Several researches have been conducted to find a practical and environmentally sound solution of the problem of scrap tires. In this context, an experimental study was conducted to provide more data on the effect of crumb rubber on the acoustic properties of self-consolidating concrete SCC. To this end, Parallelepiped and cylindrical specimens were prepared by varying the proportion of crumb rubber with percentages of 0 %, 10 %, 20 % and 30 % of the volume of gravel. Properties such standardized level difference, sound absorption at different frequency and noise reduction were investigated. The results showed that the sound absorption and noise reduction coefficient were increased according to the increase of the percentage of crumb rubber. The self-consolidating concrete rubber SCCR has better acoustic properties in comparison with SCC.

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