Effect of heat,nisin and ethylene diamine tetra‐acetate treatments on shelf life extension of liquid whole egg

This study examined the effect of nisin alone or in combination with pasteurisation or ethylene diamine tetra‐acetate (EDTA), on the shelf life of unpasteurised liquid whole egg (LWE) stored at refrigerator temperature for a period of 21 days. The shelf life of samples was determined by counting total mesophilic bacteria, yeast and mould and also pH changes. It was observed that addition of 3 ppm nisin to pasteurised LWE was effective enough to extend the shelf life of this product from about 7 days to at least 21 days. However, for unpasteurised LWE nisin alone had no significant effect on shelf life while treatment of LWE with nisin in combination with EDTA showed a significant antibacterial and antifungal activity leading to extended shelf life of unpasteurised LWE from 1 to 4 days to at least 21 days.     

General control of transition-metal-doped GaN nanowire growth: toward understanding the mechanism of dopant incorporation

We report the first synthesis and characterization of cobalt- and chromium-doped GaN nanowires (NWs), and compare them to manganese-doped GaN NWs. Samples were synthesized by chemical vapor deposition method, using cobalt(II) chloride and chromium(III) chloride as dopant precursors. For all three impurity dopants hexagonal, triangular, and rectangular NWs were observed. The fraction of NWs having a particular morphology depends on the initial concentration of the dopant precursors. While all three dopant ions have the identical effect on GaN NW growth and faceting, Co and Cr are incorporated at much lower concentrations than Mn. These findings suggest that the doping mechanism involves binding of the transition-metal intermediates to specific NW facets, inhibiting their growth and causing a change in the NW morphology. We discuss the doping concentrations of Mn, Co, and Cr in terms of differences in their crystal-field stabilization energies (DeltaCFSE) in their gas-phase intermediates and in substitutionally doped GaN NWs. Using iron(III) chloride and cobalt(II) acetate as dopant precursors we show that the doping concentration dependence on DeltaCFSE allows for the prediction of achievable doping concentrations for different dopant ions in GaN NWs, and for a rational choice of a suitable dopant-ion precursor. This work further demonstrates a general and rational control of GaN NW growth using transition-metal impurities.     

High‐Performance,Air‐Stable,Top‐Gate,p‐Channel WSe2 Field‐Effect Transistor with Fluoropolymer Buffer Layer

High‐performance, air‐stable, p‐channel WSe₂ top‐gate field‐effect transistors (FETs) using a bilayer gate dielectric composed of high‐ and low‐k dielectrics are reported. Using only a high‐k Al₂O₃ as the top‐gate dielectric generally degrades the electrical properties of p‐channel WSe₂, therefore, a thin fluoropolymer (Cytop) as a buffer layer to protect the 2D channel from high‐k oxide forming is deposited. As a result, a top‐gate‐patterned 2D WSe₂ FET is realized. The top‐gate p‐channel WSe₂ FET demonstrates a high hole mobility of 100 cm²_­ V^?1 s^?1 and a I_ON/I_OFF ratio > 10⁷ at low gate voltages (V_GS ca. ?4 V) and a drain voltage (V_DS) of ?1 V on a glass substrate. Furthermore, the top‐gate FET shows a very good stability in ambient air with a relative humidity of 45% for 7 days after device fabrication. Our approach of creating a high‐k oxide/low‐k organic bilayer dielectric is advantageous over single‐layer high‐k dielectrics for top‐gate p‐channel WSe₂ FETs, which will lead the way toward future electronic nanodevices and their integration.     

A new method for image encryption by 3D chaotic map

Pattern Analysis and Applications - Image encryption is sensitive to various attacks due to the high volume of the data and similarity of the pixels in different images. Therefore, the encryption...     

Ionic liquid-based modified cold-induced aggregation microextraction (M-CIAME) as a novel solvent extraction method for determination of gold in saline solutions

Modified-cold-induced aggregation microextraction (M-CIAME) was used for determination of gold in saline solutions. It is robust against the much higher concentration of salt (up to 40%). In this method sodium hexafluorophosphate (NaPF₆) was added to the sample solution containing Au-TMK complex and a very small amount of 1-hexyl-3-methylimidazolium tetrafluoroborate [Hmim][BF₄]. Afterward the solution was cooled in an ice bath and a cloudy solution was formed. After centrifuging, the extractant phase was analyzed using a spectrophotometric detection method. Under the optimum conditions, the limit of detection (LOD) was 0.7 ng mL^?1 and the relative standard deviation (RSD) was 1.65% for 50 ng mL^?1 gold. The method was applied for the determination of trace amount of Au in mineral and seawater with satisfactory results.