Synthesis of Composite from Bacterial Cellulose and Gold Nanoparticles

A process of bacterial cellulose gold nanocomposite has been investigated based on experimental work and cited literature. A literature review on the production process is carried out in this study. Bacterial cellulose is a high crystalline fabric material generally used in biomedical applications. A Nanocomposite was made by synthesis from gold and bacterial cellulose. The experimental work includes growing, and isolating bacterial cellulose, preparation of gold Nanoparticles and preparation of Nano composite. Nanoparticle’s formation and adsorption on the cellulose tissue have been observed visually, where a colour change was observed. The predicted particle size for the gold nanoparticles was (2-100) nm.

Spectral solution to a problem on the axisymmetric nonlinear deformation of a cylindrical membrane shell due to pressure and edges convergence

A geometrically and physically nonlinear model of a membrane cylindrical shell, which has been built and tested, describes the behavior of a airbag made of fabric material. Based on the geometrically accurate relations of "strain-displacement", it has been shown that the equilibrium equations of the shell, written in terms of Biot stresses, together with boundary conditions acquire a natural physical meaning and are the consequences of the principle of virtual work. The physical properties of the shell were described by Fung’s hyper-elastic biological material because its behavior is similar to that of textiles. For comparison, simpler hyper-elastic non-compressible Varga and Neo-Hookean materials, the zero-, first-, and second-order materials were also considered. The shell was loaded with internal pressure and convergence of edges. The approximate solution was constructed by an spectral method; the exponential convergence and high accuracy of the equilibrium equations inherent in this method have been demonstrated. Since the error does not exceed 1 % when keeping ten terms in the approximations of displacement functions, the solution can be considered almost accurate. Similar calculations were performed using a finite element method implemented in ANSYS WB in order to verify the results. Differences in determining the displacements have been shown to not exceed 0.2 %, stresses – 4 %. The study result has established that the use of Fung, Varga, Neo-Hookean materials, as well as a zero-order material, lead to similar values of displacements and stresses, from which displacements of shells from the materials of the first and second orders significantly differ. This finding makes it possible, instead of the Fung material whose setting requires a significant amount of experimental data, to use simpler ones – a zero-order material and the Varga material

Silver Nanoparticles to Increase Antibacterial Efficiency in Bandages

A Survey of WHO showed that the wound infections rates are 5 - 34% in the world. It is necessary to treat the wounds properly as it will cause more infection inside the skin. Usage of normal bandages for the treatment of wounds or infections can heal the outer surface of the skin that too by a slow process. Many researchers started investigating the different healing properties of plant based bandages. Silver nanoparticles are known for their efficient antibacterial properties. It has gained greater attention in the biomedical industries. In this study, the nanoparticles are synthesized by using environment friendly green synthesis method. Ceiba pentandra aqueous leaf extract was used as reducing and capping agent for the silver nanoparticle synthesis. It was then evenly coated on a bamboo fabric material and then assessed for its antibacterial activity by using quantitative method. It is less hazardous as no toxic chemicals are involved. The Antibacterial activity of silver nanoparticles combined with the plant extract will exhibit efficient wound healing properties. The Bandage layer can further be designed to form a completely plant based product.

Энергоемкость тканевых материалов при ударном нагружении

Space orbital stations operations support consists an adoption of meaningful measures to protect space station against impacts of space debris and meteoroids. This goal can be reached by using multilayered protection shields that are made with the fabric material layers. Shields designing and modeling requires specific characteristics that define energy absorbed volume by the fabric destruction under impact. The paper describes the methodology and experimental determination method for absorbed energy volume results by using multilayer fabrics of orbital manned stations shielding constructions under distributed impulse loading caused by the space debris impacts. The energy absorbed volume by the multilayer fabrics is obtained from the experiments by analysis of specimen and flat metal projectile impact. Projectile was accelerated by the air gas gun. The obtained experimental determination results of energy absorbed volume in pressure range up to 1,5 GPa are given. Using the model of fabric as a porous material its energy absorption volume dependence in pressure range up to 10 GPa and compared with experimental data. It is shown that for materials with high porosity absorbed energy volume against pressure dependence is close to linear. Corresponding asymptotic dependence for materials with high porosity under the high pressure is obtained.

Biological Cloth Face Coverings—The Reduction of SARS-CoV-2 and Influenza (H1N1) Infectivity by Viruferrin™ Treatment

In an attempt to create novel methods to reduce the transmission of SARS-CoV-2 and influenza viruses, fabric material was treated with Viruferrin™ and tested for its inactivating properties against the pandemic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza A viruses. Inactivating properties were evaluated by comparing Viruferrin-treated and cotton control fabric material with and without the application of saliva at various time points after virus exposure. A statistically significant (p < 0.0001) decrease in the number of infectious virus particles exposed to Viruferrin-treated fabric when compared with the cotton control for both SARS-CoV-2 and influenza A viruses was observed. For both SARS-CoV-2 and influenza A, Viruferrin-treated fabrics experienced a >99% virus reduction without saliva after five minutes of contact when compared to the positive control at time point 0. Furthermore, the reusability of the Viruferrin treated fabric was demonstrated by stability for up to 10 washes. The level of anti-viral (SARS-CoV-2) activity remained constant from 5 to 10 washes and demonstrated a significant difference (p < 0.0001) from the unwashed untreated material. Applications for this treated fabric are far reaching, as a biological face covering offers not only a unique 2-way protection but also is unlikely to cause onward touch transmission.

Analysis of Spring-in Deformation in L-shaped Profiles Pultruded at Different Pulling Speeds: Mathematical Simulation and Experimental Results

Peculiarities of the pultrusion manufacturing process lead to the occurrence of spring-in deformations, whereas their value depends on the pulling speed. In this article experimental and numerical analysis was carried out for glass fiber/vinyl ester resin 75 × 75 × 6 mm L-shaped profiles pultruded at pulling speeds of 200 and 600 mm/min. Spring-in angles of produced profiles were determined on the same day of manufacturing when profiles cooled down to room temperature. Higher pulling speeds provoked increased values of spring-in. 2D numerical model accounting for thermo-chemical and mechanical composite’s behavior during pultrusion was implemented in ABAQUS software. Cure Hardening Instantaneous Linear Elastic (CHILE) constitutive law was used to describe matrix resin Young’s modulus evolution. Since both unidirectional (UD) rovings and fabric material were utilized, effective mechanical properties of UD and fabric layers were calculated in accordance with Self-Consistent Field Micromechanics (SCFM) approach. Spring-in angles determined within experimental and numerical studies were compared and a good correlation was found: the errors were 12.6% and 6% for the pulling speed of 200 and 600 mm/min, respectively.

Biological Cloth Face Coverings - The Reduction of SARS-CoV-2 and Influenza (H1N1) Infectivity by ViruferrinTM Treatment

Fabric material was coated with Viruferrin&trade; and tested for its inactivating properties against the pandemic severe acute respiratory syndrome 2 (SARS-CoV-2) and influenza A viruses. A statistically significant (p&lt;0.0001) decrease in the number of infectious virus particles exposed to Viruferrin-treated fabric when compared with the cotton control for both SARS-CoV-2 and influenza A viruses was observed. For both SARS-CoV-2 and influenza A, Viruferrin-treated fabrics experienced a &gt; 99% virus reduction without saliva after five minutes of contact when compared to the positive control at time point 0. Furthermore, the reusability of the Viruferrin treated fabric was demonstrated by stability for up to 10 washes. The level of anti-viral (SARS-CoV-2) activity remained constant from 5 to 10 washes and demonstrated a significant difference (p&lt;0.0001) from the unwashed untreated material. Applications for this treated fabric are far-reaching, and as a biological face covering offers not only a unique 2-way protection but also is unlikely to cause onward touch transmission.

Reinforced composites with 3D fabric structures

An overview of developments in the creation and production of composites with reinforced fabric structures is presented. The advantages of using fabric reinforcing materials intertwined in a special way into a single structure are shown. Keywords: composite material, fabric material, reinforcement, preform. [email protected], [email protected]

Thermo-physiological and sensorial comfort properties of polyester and Coolmax knitted fabrics

This paper deals with thermo-physiological and sensorial comfort properties of knitted fabric samples manufactured from standard polyester (PET) and Coolmax (multi-lobal PET fiber) yarn by The Lycra Company, Wilmington, DE/USA. 18 knitted fabric samples were prepared by using PET and Coolmax. These samples were tested for qmax property related to warm/cool feeling, water-vapor transmission rate and air permeability. The results were analyzed statistically, and it was shown that fabric material used yarn to manufacture knitted samples, i.e. PET and Coolmax, has a significant effect on qmax, water-vapor transmission rate and air permeability of knitted fabric samples used in this study.