Green synthesis of mixed metallic nanoparticles using room temperature self-assembly

Bimetallic nanoparticles of silver (Ag) and gold (Au) were synthesized at room temperature using Curcumin. Reduction process of silver and gold ions with different molar ratios leads to production of different nanostructures including alloys and core-shells. Produced nanoparticles were characterized simultaneously with FTIR, UV/vis. spectroscopy, transmission electron microscopy (TEM), and Energy-dispersive X-ray (EDAX). UV/vis. optical absorption spectra of as synthesized nanoparticles reveals presence of surface palsmon resonance (SPR) of both silver at (425 nm) and gold at (540 nm) with small shift and broadness of gold band after mixing with resucing and capping agent in natural extract which suggest presence of bimetallic nano structure (Au/Ag). FTIR and EDAX data approve the presence of bimetallic nano structure combined with curcumin extract. TEM micrographs shows that silver and gold can be synthesized separately in the form of nano particles using curcumin extract. Synthesis of gold nano particles in presence of silver effectively enhance and control formation of bi-metallic structure

EFFECT OF VAPOR GARD AND CALCIUM CHLORIDE TREATMENTS ON KEEPING QUALITY OF NAVEL ORANGES AT DIFFERENT STORAGE TEMPERATURES

The experiments were conducted in two suc-cessive seasons (2004 - 2005) on Washington Na-vel orange fruits to study the effect of cold storage conditions on reducing postharvest losses and im-proving keeping quality for the export mar-ket.Fruit samples were obtained from El–Fayoum governorate, Egypt and treated with vapor gard (VG) 2%, calcium chloride (CaCl2) 4% or vapor gard 2% + calcium chloride 4%. Fruits were stored at 2 or 8 ºC for 60 days and the last group was stored at 2 ºC for 30 days and transferred to be stored at 8ºC for another 30 days at R.H. 85-90%.The results revealed that during storage fruits treated with Vapor gard (2%) alone or with calci-um chloride (4%) + Vapor gard (2%) had been in good quality as well as it caused a pronounced increase in peel color and fruit firmness, while fruit weight loss and juice percentage were de-creased. In addition, it caused a significant in-crease in ascorbic acid, total sugar and calcium concentration, but there is no significant effect in T.S.S. / acid ratio. While, free amino acid, total soluble phenols and free proline concentrations were decreased. Furthermore, the fruits storaged at 2º + 8ºC caused a pronounced increase in fruit firmness, while fruit weight losses, juice percent-age and peel color were decreased. Also, it caused a pronounced decrease in T.S.S. / acid ratio, total sugar, total free amino acid, total soluble phenols and free proline concentrations, but there is no significant effect on calcium concentration. In addition, there is an increase in ascorbic acid con-centration. Generally, the results revealed that Vapor gard either alone or combired with calcium chloride dipping treatments and stored at 2º + 8ºC had better results in improving fruit quality and decreasing total fruit losses compared with control or calcium chloride treatment alone at other stor-age temperatures and this was also accompanied by changes in various metabolic and physiological processes of orange fruits

ZnO/CuO nanocomposite-based carboxymethyl cellulose/polyethylene oxide polymer electrolytes for energy storage applications

As a part of this investigation, polymer nanocomposite films were obtained by the casting method whereby polyethylene oxide (PEO) was mixed with carboxymethyl cellulose (CMC) at a 70:30 wt ratio (PEO/CMC) as a base before adding different concentrations (0.0, 0.3, 0.8, 2, 4, and 6 wt%) of ZnO/CuO nanocomposite (ZC NC) as a dopant, prepared by the sol-gel method. Subsequent analyses revealed that, compared with the pure mixture, the dielectric parameters and conductivity of the polymer nanocomposite (CMC/PEO-ZC NC) films markedly improved with the increase of ZC NC up to 2 wt%, while a decrement was noted for 4 and 6 wt%. Thus, the optimal concentration (CMC/PEO-ZC NC 2 wt%) was used in the subsequent investigations focusing on dielectric properties, and the temperature dependence of the dielectric parameters and conductivity. As ZC NC addition yielded beneficial outcomes, the structural and morphological changes caused by the doping process were successfully counteracted, as confirmed by the x-ray diffraction (XRD) and scanning electron microscopy (SEM) results. The calculated relaxation time (τ), activation energy (Ea), and improved dielectric properties suggest that these nanocomposite films are promising candidates for the development of solid-state supercapacitors