scholarly journals Assessment of the Physical, Mechanical and Acoustic Properties of Arundo donax L. Biomass in Low Pressure and Temperature Particleboards

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1361
Author(s):  
Maria Teresa Ferrandez-García ◽  
Antonio Ferrandez-Garcia ◽  
Teresa Garcia-Ortuño ◽  
Clara Eugenia Ferrandez-Garcia ◽  
Manuel Ferrandez-Villena
Keyword(s):  
Particle Size ◽  
Absorption Coefficient ◽  
Transmission Loss ◽  
Raw Material ◽  
Acoustic Properties ◽  
Giant Reed ◽  
Sound Insulation ◽  
New Mineral ◽  
Particle Sizes ◽  
Insulation Material

Traditionally, plant fibres have been used as a raw material for manufacturing construction materials; however, in the last century, they have been replaced by new mineral and synthetic materials with manufacturing processes that consume a large amount of energy. The objective of this study was to determine the mechanical, physical and acoustic properties of panels made from giant reed residues. The article focuses on evaluating the acoustic absorption of the boards for use in buildings. The materials used were reed particles and urea–formaldehyde was used as an adhesive. The panels were produced with three particle sizes and the influence that this parameter had on the properties of the board was evaluated. To determine the absorption coefficient, samples were tested at frequencies ranging from 50 to 6300 Hz. The results showed that the boards had a medium absorption coefficient for the low and high frequency range, with significant differences depending on the particle size. The boards with 2–4 mm particles could be classified as Class D sound absorbers, while boards with particle sizes of 0.25–1 mm showed the greatest sound transmission loss. Unlike the acoustic properties, the smaller the particle size used, the better the mechanical properties of the boards. The results showed that this may be an appropriate sound insulation material for commercial use.

scholarly journals Kajian Eksperimental Koefisien Redaman Akustik Bahan Pelapis Plat Dek Kapal

2018 ◽  
Vol 3 (1) ◽  
pp. 41
Author(s):  
Wibowo Harso Nugroho ◽  
Nanang J.H. Purnomo ◽  
Hardi Zen ◽  
Andi Rahmadiansah
Keyword(s):  
Absorption Coefficient ◽  
High Frequency ◽  
Transmission Loss ◽  
Base Material ◽  
Sound Insulation ◽  
Insulation Material ◽  
Base Materials ◽  
Specimen Material ◽  
Ship Classification ◽  
Technical Assessment

With the increasingly strict requirements of the ship classification bureau for permissible noise limits to allow passengers and crew to be more comfortable and secure a technical assessment is required to address the characteristics of the noise. A noise beyond the standard allowed in the vessel can be a problem to the ship operators. This noise problem will greatly affects the crews' comfort and passengers. One method to reduce the noise on a ship is to use sound insulation. This paper describes the method for determining the absorption coefficient α and the transmission loss (TL) through an acoustic test of a concrete insulation in the laboratory. The test was conducted by using the method of impedance tube where a speciment response measured by a microphone. In general, the properties of this insulation material remains as the main base material which is concrete. it has been found that the transmission loss value (TL) is in the range of 10 - 50 dB whereas for the base material the concrete is around 22 - 49 dB but the absorption coefficient α of the specimen material is much higher than the material of the base material especially in high frequency, which ranges from 0.15 to 0.97, whereas for concrete base materials have absorbent coefficient α ranges from 0.01 to 0.02.

Computational Characterization of Double Porosity Metamaterials for Broadband Sound Insulation

2017 ◽  
Author(s):  
Shichao Cui ◽  
Ryan L. Harne
Keyword(s):  
Absorption Coefficient ◽  
Transmission Loss ◽  
Functional Dependence ◽  
Double Porosity ◽  
Acoustic Properties ◽  
Sound Insulation ◽  
Low Frequencies ◽  
Static Compression ◽  
Poroelastic Media ◽  
Additional Influence

This research investigates the sound insulation properties — sound absorption coefficient and transmission loss — of a double porosity metamaterial and the functional dependence of such properties on the selection of underlying poroelastic material. The internal metamaterial geometry enables a global rotation phenomenon when the system is under a static compression. Using the finite element method, the influence of such compression upon the acoustic properties is quantified for its role in enhancing and tailoring sound insulation characteristics, while the additional influence of embedded rigid inclusions is examined. By applying these concepts to metamaterials composed from different poroelastic media, it is found that the acoustic properties can be tuned over strategic frequency ranges of relevance for sound insulation. In particular, the results demonstrate that for certain metamaterial compositions the absorption coefficient can be increased by about 100% and the transmission loss enhanced by 20% across a broad range of low frequencies by the introduction of the inclusions, while the compression constraint can increase the properties by 10 to 20% across narrow frequency bands. The outcomes suggest new possibilities for greatly enhancing the acoustic insulation properties of poroelastic materials in applications where space is limited and/or where added mass is not a concern.

Use of Ceramic Waste for the Manufacture of Sintered Parts

2020 ◽  
Vol 1012 ◽  
pp. 233-238
Author(s):  
Vanessa Moura de Souza ◽  
Vinícius Martins ◽  
Rejane Maria Candiota Tubino
Keyword(s):  
Particle Size ◽  
Selection Process ◽  
Compaction Pressure ◽  
Raw Material ◽  
Powder Technology ◽  
Particle Sizes ◽  
Compression Pressure ◽  
X Ray ◽  
Ceramic Waste ◽  
Quality Process

This paper evaluated the use of the pitcher, a ceramic waste obtained through the quality process of a sanitary ware industry, in the development of a material for usage in the manufacture of sintered parts. The pitcher was obtained through powder technology and is composed, according to the chemical analysis obtained by X-ray fluorescence spectrometry, of clayey minerals (clay and kaolin), quartz, and feldspar, which may include ceramic rocks such as granite, pegmatite and phyllite; that is, it has proved to be a potential raw material due to the minerals that can still be reused. The pitcher passed through a granulometry-based selection process, sieving about 20kg using the following sieve sequence: 18 MESH, 25 MESH, 30 MESH, 120 MESH and 400 MESH; with around 70% of the residue being retained in the sieves of 120 and 400 MESH, which were selected to be used in the evaluation. The samples were compacted in a manual press with different pressures, between 300 and 1000 kgf, and after were sintered at a temperature of 1100oC in a resistive furnace. To characterize the material, the apparent and green density, as well as the compressibility curve, were determined to identify the best compression pressure. The microstructure of the test specimen and the pitcher homogeneity were evaluated using Scanning Electron Microscopy (SEM). Both particle sizes presented the typical compressibility curve, in which the density increases with increasing compaction pressure, while the curve slope decreases with increasing pressure. The density increase with the increasing compaction pressure indicates a good densification for the temperatures, independent of the sample granulometry. The sintering porosity decreased proportionally to the particle size in the sintered samples. The analysis showed that the particle size of 400 MESH sintered at 1100oC obtained more porous surfaces, thus indicating a promising future for the manufacture of parts using powder technology, especially for the development of filters.

scholarly journals Non-Wovens as Sound Reducers

2018 ◽  
Vol 55 (2) ◽  
pp. 64-76
Author(s):  
D. Belakova ◽  
A. Seile ◽  
S. Kukle ◽  
T. Plamus
Keyword(s):  
Absorption Coefficient ◽  
Surface Density ◽  
Sound Absorption ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Sound Insulation ◽  
Material Structure ◽  
Sound Transmission Loss ◽  
Sound Waves ◽  
Frequency Range

Abstract Within the present study, the effect of hemp (40 wt%) and polyactide (60 wt%), non-woven surface density, thickness and number of fibre web layers on the sound absorption coefficient and the sound transmission loss in the frequency range from 50 to 5000 Hz is analysed. The sound insulation properties of the experimental samples have been determined, compared to the ones in practical use, and the possible use of material has been defined. Non-woven materials are ideally suited for use in acoustic insulation products because the arrangement of fibres produces a porous material structure, which leads to a greater interaction between sound waves and fibre structure. Of all the tested samples (A, B and D), the non-woven variant B exceeded the surface density of sample A by 1.22 times and 1.15 times that of sample D. By placing non-wovens one above the other in 2 layers, it is possible to increase the absorption coefficient of the material, which depending on the frequency corresponds to C, D, and E sound absorption classes. Sample A demonstrates the best sound absorption of all the three samples in the frequency range from 250 to 2000 Hz. In the test frequency range from 50 to 5000 Hz, the sound transmission loss varies from 0.76 (Sample D at 63 Hz) to 3.90 (Sample B at 5000 Hz).

Microstructure and performance characteristics of acoustic insulation materials from post-consumer recycled denim fabrics

2020 ◽  
pp. 152808372094074
Author(s):  
Shafiqul Islam ◽  
Magdy El Messiry ◽  
Partha Pratim Sikdar ◽  
Joshua Seylar ◽  
Gajanan Bhat
Keyword(s):  
Transmission Loss ◽  
Value Added ◽  
Areal Density ◽  
Vital Role ◽  
Sound Insulation ◽  
Insulation Material ◽  
Human Beings ◽  
Insulation Materials ◽  
Sustainable Products ◽  
Acoustic Insulation

One of the key issues of the 21st century is to reduce the rate of continuously increasing environmental pollution from waste generated by human beings. Use of recycled materials and environmentally friendly approaches to manufacturing can be a good way to deal with these challenges. Similarly, sound pollution has been increasing at an alarming rate due to industrialization and modernization. Use of acoustic insulation materials produced from recycled textile waste can play a vital role in reduction of sound pollution while simultaneously helping reduce municipal solid waste. The goal of this study was to evaluate the recycling of used apparels to produce commercially feasible sustainable products using nonwoven fabrication techniques with a biodegradable thermoplastic binder fiber for possible use as acoustic insulation panels. Recycled denim fibers were used with Sorona® or a PLA binder fiber to successfully produce sound insulation with good performance properties. Maximum transmission loss of about 24 dB and transmission coefficient close to zero at around 1000 Hz were observed. The data indicated that there is a direct correlation between loss of sound transmission with increase in thickness, areal density and decrease in air permeability. When compared with commercially available acoustic insulation material (gypsum board), these products had better insulation properties, indicating that recycled textile products can be used to produce such value-added materials, giving them another useful life before safely disposing in composting environments.

Preparation of Exfoliated Graphite by Microwave Using Natural Graphite with Different Particle Sizes

2010 ◽  
Vol 163-167 ◽  
pp. 2333-2336 ◽  
Author(s):  
Kun Yu
Keyword(s):  
Particle Size ◽  
Microwave Irradiation ◽  
Small Particle ◽  
Graphite Particle ◽  
Microwave Oven ◽  
Raw Material ◽  
Exfoliated Graphite ◽  
Particle Sizes ◽  
Natural Graphite ◽  
Graphite Intercalation

Three natural graphite flakes (35, 50 and 80 mesh) were used as raw material. Exfoliated graphite (EG) was prepared by rapidly heating residue H2SO4-graphite intercalation compounds (RGIC) in a muffle and by irradiating it in a microwave oven, respectively. Results show that the exfoliation volume of EG decreases with decreasing the raw graphite particle size. Compared with muffle heating, microwave irradiation is more helpful for the exfoliation of RGICs, especially for the small particle samples.

scholarly journals The Effects of Various Additive Components on the Sound Absorption Performances of Polyurethane Foams

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Shuming Chen ◽  
Yang Jiang ◽  
Jing Chen ◽  
Dengfeng Wang
Keyword(s):  
Absorption Coefficient ◽  
Sound Absorption ◽  
Transmission Loss ◽  
Polyurethane Foams ◽  
Acoustic Properties ◽  
Acoustic Absorption ◽  
Absorption Properties ◽  
Maximum Enhancement ◽  
Flexible Polyurethane ◽  
Pu Foams

Flexible polyurethane (PU) foams comprising various additive components were synthesized to improve their acoustic performances. The purpose of this study was to investigate the effects of various additive components of the PU foams on the resultant sound absorption, which was characterized by the impedance tube technique to obtain the incident sound absorption coefficient and transmission loss. The maximum enhancement in the acoustic properties of the foams was obtained by adding fluorine-dichloroethane (141b) and triethanolamine. The results showed that the acoustic absorption properties of the PU foams were improved by adding 141b and triethanolamine and depended on the amount of the water, 141b, and triethanolamine.

Structural Evolution of Natural Flake Graphite with Different Particle Sizes during the Intercalation and Exfoliation Processes

2011 ◽  
Vol 80-81 ◽  
pp. 221-224
Author(s):  
Xue Qing Yue ◽  
Yan Lu ◽  
Dong Hua Lu
Keyword(s):  
Particle Size ◽  
Graphite Particle ◽  
Structural Evolution ◽  
Intercalation Compounds ◽  
Raw Material ◽  
Particle Sizes ◽  
Flake Graphite ◽  
Material Particle ◽  
Graphite Intercalation ◽  
Reaction Degree

In order to investigate the structural evolution of natural flake graphite with different particle sizes during the intercalation and exfoliation process, we used three natural graphites, 35, 50 and 80 mesh, as the raw material and investigated the characteristics of the three chemically prepared graphite intercalation compounds (GICs) of H2SO4 and the three corresponding residue GICs (RGICs). Expanded graphites (EGs) were prepared by rapidly heating the RGICs to 1000 °C in a muffle. The Results show that with decreasing the raw graphite particle size, the oxidizing reaction degree of GIC increases, but the intercalating reaction degree decreases. For RGICs, the relative ratio of RGIC phase in a sample decreases with decreasing the raw material particle size. In addition, decreasing the raw graphite particle size decreases the expanded volume of EG.

scholarly journals Effectiveness of fused magnesium potassium phosphate for marandu grass

2009 ◽  
Vol 33 (6) ◽  
pp. 1855-1862 ◽  
Author(s):  
Valdeci Orioli Júnior ◽  
Edson Luiz Mendes Coutinho
Keyword(s):  
Particle Size ◽  
Dry Matter ◽  
Potassium Phosphate ◽  
Raw Material ◽  
High Price ◽  
Particle Sizes ◽  
Clay Loam ◽  
Critical Levels ◽  
Sandy Clay Loam ◽  
Matter Production

The current high price of KCl and great dependence on importation to satisfy the Brazilian demand indicate the need for studies that evaluate the efficiency of other K sources, particularly those based on domestic raw material. For this purpose, a greenhouse experiment was conducted with samples of a sandy clay loam Typic Haplustox, in a completely randomized 4 x 3 x 2 factorial design: four K rates (0, 60, 120, and 180 mg kg-1), three sources (potassium chloride (KCl), fused magnesium potassium phosphate (FMPP) and a mixture of 70 % FMPP + 30 % KCl) and two particle sizes (100 and 60 mesh), with three replications. Potassium fertilization resulted in significant increases in shoot dry matter production and in K concentrations, both in soil and plants. The K source and particle size had no significant effect on the evaluated characteristics. Potassium critical levels in the soil and the shoots were 1.53 mmol c dm-3 and 19.1 g kg-1, respectively.

scholarly journals Acoustic Properties of 316L Stainless Steel Hollow Sphere Composites Fabricated by Pressure Casting

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1047
Author(s):  
Chunhe Wang ◽  
Fengchun Jiang ◽  
Shuaiqi Shao ◽  
Tianmiao Yu ◽  
Chunhuan Guo
Keyword(s):  
Absorption Coefficient ◽  
Hollow Sphere ◽  
Sound Absorption ◽  
Random Distribution ◽  
Transmission Loss ◽  
Acoustic Properties ◽  
Sound Absorption Coefficient ◽  
Pressure Casting ◽  
Sound Transmission Loss ◽  
At Resonance

In this study, we prepared metal hollow sphere composites (MHSCs) using metal hollow spheres (MHSs) by pressure casting under vacuum conditions, and investigated the acoustic properties. The density of the MHSCs was measured using the mass to volume ratio, the microstructure of the MHSCs was observed using a scanning electron microscope, and the acoustic properties of the MHSCs were tested using an impedance tube. The measured MHSCs showed that the densities of the MHSCs with the random distribution of MHSs with diameter ~3.28 mm (1.74 g/cm3 to 1.77 g/cm3) (MHSC-3.28) were nearly equal to that of the MHSCs with the random distribution of MHSs with diameter ~5.76 mm (1.74 g/cm3 to 1.76 g/cm3) (MHSC-5.76), and lower than that of the MHSCs with the layered structure of MHSs with diameter ~3.28 mm (1.93 g/cm3 to 1.97 g/cm3) (MHSC-LS). Microstructural observations confirmed that the interface region between the MHSs and matrix demonstrated a simple physical combination pattern with pores. The acoustic properties of the MHSCs showed that the sound absorption coefficient of MHSC-LS was lower than that of MHSC-3.28 and higher than that of MHSC-5.76 at off-resonance. The sound absorption coefficient peak value of MHSC-3.28 was higher than that of MHSC-LS, and lower than that of MHSC-5.76 at resonance. The sound transmission loss of MHSC-3.28 was lower than that of MHSC-5.76, which shows the rules are independent from the resonance. The sound transmission loss of MHSC-LS was higher than that of MHSC-5.76 at resonance, but lower than that of MHSC-3.28 at off-resonance. In addition, we discuss the propagation mechanism of the sound waves in the MHSC, which is mainly determined by the distribution of the MHSs in the MHSC.

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