Acoustic characterization of silica nanoparticle-impregnated Kevlar fabric

Textile Research Journal ◽

10.1177/00405175211023812 ◽

2021 ◽

pp. 004051752110238

Author(s):

Oluwafemi P Akinmolayan ◽

James M Manimala

Keyword(s):

Transmission Loss ◽

Silica Nanoparticle ◽

Air Gap ◽

Thin Plates ◽

Residual Porosity ◽

Ballistic Performance ◽

Number Of Layers ◽

Structural Applications ◽

Acoustic Characterization

Silica nanoparticle-impregnated Kevlar (SNK) fabric has better specific ballistic performance in comparison to its neat counterparts. For multifunctional structural applications using lightweight composites, combining this improved ballistic functionality with an acoustic functionality is desirable. In this study, acoustic characterization of neat and SNK samples is conducted using the normal-incidence impedance tube method. Both the absorption coefficient and transmission loss (TL) are measured in the 60–6000 Hz frequency range. The influence of parameters such as number of layers of neat or treated fabric, percentage by weight of nanoparticle addition, spacing between fabric layers, and residual porosity is examined. It is found that while absorption decreases with an increase in nanoparticle addition for frequencies above about 2500 Hz, increasing the number of layers shifts peak absorption to lower frequencies. By introducing an air-gap behind the fabric layer, dominant low-frequency (1000–3000 Hz) absorption peaks are obtained that correlate well with natural modes of mass-equivalent thin plates. Examining the influence of residual porosity by laminating the SNK samples reveals that it contributes to about 30–50% of the total absorption. Above about 1500 Hz, 3–5 dB of TL increase is obtained for SNK samples vis-à-vis the neat samples. TL is found to increase beyond that of the neat sample above a threshold frequency when an air-gap is introduced between two SNK layers. With an increase in the weight of nanoparticle addition, measured TL tends to be closer to mass law predictions. This study demonstrates that SNK fabric could provide improved acoustic performance in addition to its ballistic capabilities, making it suitable for multifunctional applications and could form the basis for the development of simplified models to predict the structural acoustic response of such nanoparticle–fabric composites.

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Acoustic Characterization of Marine Sediments

10.21236/ada627576 ◽

1997 ◽

Author(s):

Anatoliy N. Ivakin ◽

Darrell R. Jackson

Keyword(s):

Marine Sediments ◽

Acoustic Characterization

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Microscopic Image Segmentation and Morphological Characterization of Novel Chitosan/Silica Nanoparticle/Nisin Films Using Antimicrobial Technique for Blueberry Preservation

Membranes ◽

10.3390/membranes11050303 ◽

2021 ◽

Vol 11 (5) ◽

pp. 303

Author(s):

Rokayya Sami ◽

Schahrazad Soltane ◽

Mahmoud Helal

Keyword(s):

Ph Value ◽

Silica Nanoparticle ◽

Morphological Characterization ◽

Aerobic Bacteria ◽

Nano Materials ◽

Elongation At Break ◽

Stable Suspension ◽

Average Size ◽

Material Ductility

In the current work, the characterization of novel chitosan/silica nanoparticle/nisin films with the addition of nisin as an antimicrobial technique for blueberry preservation during storage is investigated. Chitosan/Silica Nanoparticle/N (CH-SN-N) films presented a stable suspension as the surface loads (45.9 mV) and the distribution was considered broad (0.62). The result shows that the pH value was increased gradually with the addition of nisin to 4.12, while the turbidity was the highest at 0.39. The content of the insoluble matter and contact angle were the highest for the Chitosan/Silica Nanoparticle (CH-SN) film at 5.68%. The use of nano-materials in chitosan films decreased the material ductility, reduced the tensile strength and elongation-at-break of the membrane. The coated blueberries with Chitosan/Silica Nanoparticle/N films reported the lowest microbial contamination counts at 2.82 log CFU/g followed by Chitosan/Silica Nanoparticle at 3.73 and 3.58 log CFU/g for the aerobic bacteria, molds, and yeasts population, respectively. It was observed that (CH) film extracted 94 regions with an average size of 449.10, at the same time (CH-SN) film extracted 169 regions with an average size of 130.53. The (CH-SN-N) film presented the best result at 5.19%. It could be observed that the size of the total region of the fruit for the (CH) case was the smallest (1663 pixels), which implied that the fruit lost moisture content. As a conclusion, (CH-SN-N) film is recommended for blueberry preservation to prolong the shelf-life during storage.

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Experimental and Numerical Analyses on the Buckling Characteristics of Woven Flax/Epoxy Laminated Composite Plate under Axial Compression

Polymers ◽

10.3390/polym13070995 ◽

2021 ◽

Vol 13 (7) ◽

pp. 995

Author(s):

Venkatachalam Gopalan ◽

Vimalanand Suthenthiraveerappa ◽

Jefferson Stanley David ◽

Jeyanthi Subramanian ◽

A. Raja Annamalai ◽

...

Keyword(s):

Environmental Sustainability ◽

Composite Plate ◽

Compressive Load ◽

Laminated Composite ◽

Green Composite ◽

Laminated Composite Plate ◽

Axial Compressive Load ◽

Number Of Layers ◽

Structural Applications ◽

Ply Orientation

The evolution of a sustainable green composite in various loadbearing structural applications tends to reduce pollution, which in turn enhances environmental sustainability. This work is an attempt to promote a sustainable green composite in buckling loadbearing structural applications. In order to use the green composite in various structural applications, the knowledge on its structural stability is a must. As the structural instability leads to the buckling of the composite structure when it is under an axial compressive load, the work on its buckling characteristics is important. In this work, the buckling characteristics of a woven flax/bio epoxy (WFBE) laminated composite plate are investigated experimentally and numerically when subjected to an axial compressive load. In order to accomplish the optimization study on the buckling characteristics of the composite plate among various structural criterions such as number of layers, the width of the plate and the ply orientation, the optimization tool “response surface methodology” (RSM) is used in this work. The validation of the developed finite element model in Analysis System (ANSYS) version 16 is carried out by comparing the critical buckling loads obtained from the experimental test and numerical simulation for three out of twenty samples. A comparison is then made between the numerical results obtained through ANSYS16 and the results generated using the regression equation. It is concluded that the buckling strength of the composite escalates with the number of layers, the change in width and the ply orientation. It is also noted that the weaving model of the fabric powers the buckling behavior of the composite. This work explores the feasibility of the use of the developed green composite in various buckling loadbearing structural applications. Due to the compromised buckling characteristics of the green composite with the synthetic composite, it has the capability of replacing many synthetic composites, which in turn enhances the sustainability of the environment.

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Low temperature acoustic characterization of PMN single crystal

Journal of Applied Physics ◽

10.1063/1.5000361 ◽

2017 ◽

Vol 122 (8) ◽

pp. 084103 ◽

Cited By ~ 1

Author(s):

E. Smirnova ◽

A. Sotnikov ◽

S. Ktitorov ◽

H. Schmidt

Keyword(s):

Low Temperature ◽

Single Crystal ◽

Acoustic Characterization

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Acoustic Characterization of Some Steel Industry Waste Materials

Applied Sciences ◽

10.3390/app11135924 ◽

2021 ◽

Vol 11 (13) ◽

pp. 5924

Author(s):

Elisa Levi ◽

Simona Sgarbi ◽

Edoardo Alessio Piana

Keyword(s):

Thermal Characteristic ◽

Environmental Benefits ◽

Acoustic Properties ◽

Physical Parameters ◽

Industry Waste ◽

Acoustic Characterization ◽

Minimization Procedure ◽

The Difference ◽

By Products

From a circular economy perspective, the acoustic characterization of steelwork by-products is a topic worth investigating, especially because little or no literature can be found on this subject. The possibility to reuse and add value to a large amount of this kind of waste material can lead to significant economic and environmental benefits. Once properly analyzed and optimized, these by-products can become a valuable alternative to conventional materials for noise control applications. The main acoustic properties of these materials can be investigated by means of a four-microphone impedance tube. Through an inverse technique, it is then possible to derive some non-acoustic properties of interest, useful to physically characterize the structure of the materials. The inverse method adopted in this paper is founded on the Johnson–Champoux–Allard model and uses a standard minimization procedure based on the difference between the sound absorption coefficients obtained experimentally and predicted by the Johnson–Champoux–Allard model. The results obtained are consistent with other literature data for similar materials. The knowledge of the physical parameters retrieved applying this technique (porosity, airflow resistivity, tortuosity, viscous and thermal characteristic length) is fundamental for the acoustic optimization of the porous materials in the case of future applications.

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