scholarly journals A Review on Acoustical Properties Measurement Methods and a Proposed Novel Method for Acoustical Characterization of Laminated Glass used in Automotive Applications

Author(s):  
Sudhanshu Krishna Sharma et.al., Sudhanshu Krishna Sharma et.al., ◽  
Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1807
Author(s):  
Rocío Guerle-Cavero ◽  
Blanca Lleal-Fontàs ◽  
Albert Balfagón-Costa

In 2023, new legislation will ban the use of animals in the cosmetic industry worldwide. This fact, together with ethical considerations concerning the use of animals or humans in scientific research, highlights the need to propose new alternatives for replacing their use. The aim of this study is to create a tri-layered chitosan membrane ionically crosslinked with sodium tripolyphosphate (TPP) in order to simulate the number of layers in human skin. The current article highlights the creation of a membrane where pores were induced by a novel method. Swelling index, pore creation, and mechanical property measurements revealed that the swelling index of chitosan membranes decreased and, their pore formation and elasticity increased with an increase in the Deacetylation Grade (DDA). Additionally, the results demonstrate that chitosan’s origin can influence the elastic modulus value and reproducibility, with higher values being obtained with seashell than snow crab or shrimp shells. Furthermore, the data show that the addition of each layer, until reaching three layers, increases the elastic modulus. Moreover, if layers are crosslinked, the elastic modulus increases to a much greater extent. The characterization of three kinds of chitosan membranes was performed to find the most suitable material for studying different human skin properties.


2013 ◽  
Vol 205-206 ◽  
pp. 284-289 ◽  
Author(s):  
David Lysáček ◽  
Petr Kostelník ◽  
Petr Pánek

We report on a novel method of low pressure chemical vapor deposition of polycrystalline silicon layers used for external gettering in silicon substrate for semiconductor applications. The proposed method allowed us to produce layers of polycrystalline silicon with pre-determined residual stress. The method is based on the deposition of a multilayer system formed by two layers. The first layer is intentionally designed to have tensile stress while the second layer has compressive stress. Opposite sign of the residual stresses of the individual layers enables to pre-determine the residual stress of the gettering stack. We used scanning electron microscopy for structural characterization of the layers and intentional contamination for demonstration of the gettering properties. Residual stress of the layers was calculated from the wafer curvature.


Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1622 ◽  
Author(s):  
Hamzé Karaky ◽  
Chadi Maalouf ◽  
Christophe Bliard ◽  
Tala Moussa ◽  
Nadim El Wakil ◽  
...  

This article deals with the elaboration and the characterization of an innovative 100% plant-based green composite made solely of beet pulp (BP) and potato starch (S). Using this type of material in insulation applications seems a good solution to reduce the CO2 gas emissions in building. The influence of the starch amount on composite characteristics was studied. Four mixtures were considered with different S/BP mass ratios (0.1, 0.2, 0.3 and 0.4). The physical properties of these materials were studied in terms of porosity, apparent and absolute densities, thermal conductivity, and hygric properties. The influence of humidity content on acoustical properties was studied as a function of frequency. Test results show a real impact of both starch and humidity contents on the hygrothermal and acoustical properties of the studied material due to the porosity. The composite with the lowest amount of starch (S/BP = 0.1) seems to be the optimal composition in terms of the hygrothermal and acoustical behaviors.


2019 ◽  
Vol 23 ◽  
pp. 201-212
Author(s):  
Shivkumari Panda ◽  
Dibakar Behera ◽  
Tapan Kumar Bastia

This chapter presents the preparation and characterization of some unique properties of nanocomposites by dispersing graphite flakes in commercial unsaturated polyester (UPE) matrix. The composite was prepared by a novel method with the use of solvent swelling technique. Three different specimens of UPE/graphite nanocomposites were fabricated with addition of 1, 2 and 3 wt% of graphite flakes. Except mechanical, viscoelastic and thermo gravimetric properties, transport properties like electrical conductivity, thermal conductivity and water transport properties were studied for the first time. Graphite flakes propose enhanced properties to the composites suggesting homogeneous distribution of the nanofiller in the matrix and strong interaction with the matrix. 2wt% nanofiller loading showed superior essential characteristics and after that the properties reduced may be due to the nucleating tendency of the nanofiller particles. The XRD pattern showed the compatibility of the graphite flakes by introducing a peak around 26.550 in the nanocomposites. SEM Properties are also in agreement with the compatibility. Nanocomposite with 2wt% graphite also showed remarkable enhancement in transport, mechanical, viscoelastic and thermo gravimetric properties. So by introduction of a small quantity of graphite endow the new class of multiphase nanocomposites with inimitable structure and tremendous application.


2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Goran Pavić ◽  
Andrew S. Elliott

A novel method has been outlined in the first part of this paper aimed at characterization of structure-borne sound transmission from a vibration source coupled via resilient mounts to a receiver. It can deliver the source mobility and its free velocity, together with the mobility of the receiver to which the source is connected, without decoupling the two structures. The only condition which has to be fulfilled is the conservation of coupling forces and moments across the mounts. In this part of the paper the method is examined from the feasibility point of view. A benchmark test is used as a validation reference for the method, where the properties of the resilient mounts are required and are assumed as known but not completely certain. The feasibility of the principal method is tested by virtual experiment involving two built-up plates resiliently connected at several points. The comparison of the benchmark and the principal method is used to illustrate the benefits of the latter given a small error in the supposedly known mount properties.


Sign in / Sign up

Export Citation Format

Share Document