We show that the quadratic interaction of fundamental and second harmonics in a bulk dispersive medium, combined with self-defocusing cubic nonlinearity, gives rise to completely localized spatiotemporal solitons (vortex tori) with vorticity s=1. There is no threshold necessary for the existence of these solitons. They are found to be stable if their energy exceeds a certain critical value, so ...

Isolation and enrichment of multiclass pesticides’ residue, namely, fungicides (benalaxyl), herbicides (atrazine), carbamate insecticides (carbofuran), organophosphate (chlorpyrifos), organochlorine (4,4′-DDT), pyrethroid (bifenthrin), were made by combining acetone-based salting-out assisted extraction with the dispersive liquid-liquid microextraction (SADLLME) method, followed high-performanc...

Background and Objectives: Furfural (F) and hydroxymethyl furfural (HMF) are cyclic aldehydes, which are formed during the heat processing of foods. These chemical contaminants have received much attention due to their suspected health hazards and heat damage indicators. The aim of the present study was extraction and determination of F and HMF in baby-foods using dispersive liquid-liquid micro...

In the proposed method, carbon tetrachloride and ethanol were used as extraction and dispersive solvents. Several factors that may be affected on the extraction process, such as extraction solvent, disperser solvent, the volume of extraction and disperser solvent, pH of the aqueous solution and extraction time were optimized. Under the optimal conditions, linearity was maintained between 1.0 ng...

6 In this study, a total of 370 rice samples collected from six provinces in China were 7 surveyed for the presence of aflatoxins (AFs) and ochratoxin A (OTA) using 8 dispersive liquid-liquid microextraction coupled to liquid chromatography with 9 fluorescence detection. The results obtained in this survey showed that 63.5% 10 (235/370) and 4.9% (18/370) of rice samples contained detectable amo...