A coloured polyester fabric with antimicrobial properties conferred by copper nanoparticles

In this study, we aimed to produce a coloured polyester fabric through the in situ sonosynthesis of copper nanoparticles using copper sulphate, hydrazine, sodium hydroxide and polyvinylpyrrolidone. The treated fabrics were characterised by X‐ray diffraction, field emission scanning electron microscopy, energy‐dispersive X‐ray spectroscopy and elemental mapping. Moreover, mechanical properties, wettability and antibacterial/antifungal activities of the treated fabrics were evaluated. Central composite design based on the response surface methodology was used to study the effect of copper sulphate, hydrazine hydrate and sodium hydroxide on the weight gain and colour of the treated fabrics. In addition to their roles as reducing agents, hydrazine and sodium hydroxide were responsible for the simultaneous aminolysis and hydrolysis of polyester, increasing the adsorption of nanoparticles on the surface. According to the results, the reddish brown samples treated with copper nanoparticles showed excellent antibacterial and antifungal efficiencies, improved tensile strength and decreased wettability.     

Automatic Voltage Regulation of Grid Connected Photovoltaic System Using Lyapunov Based Sliding Mode Controller: A Finite — Time Approach

International Journal of Control, Automation and Systems - Importance of PV based energy systems cannot be denied with quickly increase in renewable energy demand. Due to inherent uncertainties and...     

An evaluation of energy balance parameters,and the relations between topographical and biophysical characteristics using the mountainous surface energy balance algorithm for land (SEBAL)

Energy balance parameters are very important in various applications such as energy global cycle, environment, climatic change monitoring, weather forecast, agriculture. The present study evaluates the influence of topographical conditions on the amount of downward shortwave radiation (SWD) of the surface, as well as the relation between surface Net radiation with biophysical characteristics and region’s land use’s. For this purpose, Landsat images, Digital Elevation Model (DEM), and a set of sample points have been used. To calculate the downward shortwave radiation and Net radiation fluxes, it has employed the mountainous SEBAL algorithm. Greenness, Brightness, Wetness, Normalization Difference Built-up Index (NDBI), Normalization Difference Vegetation Index (NDVI) and Albedo parameters considered as surface biophysical characteristics. Brightness, NDBI and Albedo information shows the percentage of impervious? surfaces while Greenness and NDVI information is related to vegetation percentage and Wetness information concerns water-related rates as well as the wetness of the soil, plant, and built-up lands. Statistical analysis has been used to study the relationship between different parameters. Results show that the slope is the most influential topographical parameters on the amount of SWD of the surface. There is a reverse relation between the variants of SWD of the surface, and the slope of the surface, in second-degree polynomial form with a Pearson’s correlation coefficient (r) of 0.82. North aspect receive the minimum SWD average with a 681 W m^–2 while flat lands receive the maximum SWD average with a 783 W m^–2. Areas with the highest elevation, lowest slope, and flatlands, receive the highest SWD. Built-up lands have the lowest Net radiation flux average with a 595 W m^–2 while water has the highest Net radiation flux average with a 761 W m^–2. Net radiation flux is directly related with NDVI, Greenness and Wetness parameters, while it is reversely related to NDBI, Albebo and Brightness with a high r.     

Dual-functioning core@shell nanofiber strip for enhancing drinking water quality: Polysulfone/graphene oxide adsorbent core layer and polyvinylpyrrolidone/mint sacrificial shell layer

Drinking water quality is considered a continuing concern of human health. Herein, for the improvement of water quality, dual functioning core-shell (CS) nanofibers were developed by use of polysulfone (PSU)/graphene oxide (GO) as the adsorbent core layer for removing heavy metal ions and polyvinylpyrrolidone (PVP)/mint extract as the shell layer for inducing antioxidant activity to the water. Various analyses on the strip samples before and after the water treatment experiment were performed. ATR-FTIR by appearing or disappearing chemical bonds, TEM micrographs based on the formation of shell layer around the nanofibers, FESEM according to the uniformity and diameter of nanofibers, and EDX analysis based on the elemental and mapping results, verified the core-shell structure of nanofibers. The results of the antioxidant activity demonstrated that after the dissolution shell layer, radical scavenging capability of water was improved effectively. Thereafter, the remained core layer had a high capacity and efficiency for the adsorption of metal ions especially for CS3 with 70.9% and 58.7% efficiency for Fe(III) and Ni(II). By achieving 0.975 and 0.568 L/g partition coefficient (PC), the desired performance of CS3 (core layer: 15 wt% PSU, 0.5% GO and shell layer: 5 wt% PVP, and 2.5 wt% mint) was confirmed.