The TiO2/ZnO nanocomposite as a photocatalyst was prepared with different molar ratios of ZnO using the sol–gel method. The structures and properties were recognized with Fourier transform infra-red spectroscopy (FT-IR), scanning electron microscopy (SEM), and X-ray diffraction (XRD) methods. The XRD study exhibited that the crystallization behavior of the nanocomposites was associated with the molar ratios of ZnO. The SEM images indicated that with increasing the molar ratio of TiO2/ZnO until 50:10, regular morphology can be seen. It should be of interest for catalytic purposes since it expectantly improves the surface area. Furthermore, the photocatalytic activity of the synthesized nanocomposites was investigated for decolorization of Methylene Blue (MB) in water under UV irradiation in a batch reactor. The results revealed that the photocatalytic activity of nanocomposite with 50:10M ratio of TiO2/ZnO was the best

A novel surfactant-assisted dispersive liquid–liquid microextraction (SADLLME) based on solidification of floating organic drop (SFO) combined with high-performance liquid chromatography-ultraviolet detection (HPLC-UV) has been proposed for extraction and determination of amphetamine (AM) and methamphetamine (MA) in urine samples. 1-undecanol and sodium dodecyl sulfate (SDS) were used as extracting solvent and disperser, respectively. Face-centered central composite design (FCCCD) was used for optimization of several factors affecting extraction recovery. The optimal conditions were pH = 6.4, volume of extracting solvent V = 31.0 μL, 0.08 CMC as surfactant concentration, and the amount of NaCl for ionic strength was 0.3% (W/V). The limits of detection (LODs, S/N = 3) of the extraction method were 2 for AM and 3 μg L⁻¹ for MA, with the enrichment factors (EFs) of 56 and 48 folds, respectively. The relative standard deviation (RSD %) for n = 3 was below 5.6% and a good linearity (R² > 0.991) in the range of 10–2000 μg L⁻¹ was observed. The application feasibility of SFO-SADLLME-HPLC-UV in real sample was investigated by analyzing different real samples and satisfactory results were obtained.

Kope cheese has been characterized based on gross chemical composition, free fatty acids (FFAs), organic acids (OAs), volatile compounds (VCs), and sensory attributes (SAs) during 187 days of the ripening period. C16:0, C18:1cisΔ9, and C14:0 were the most abundant FFAs. Lactic and acetic acids were the most prevalent OAs affecting sensory properties. principal component analysis (PCA) indicated that butanoic acid, butyl hexanoate, and 2,3‐butanediol were as key VCs. Protein contents, pH (based on FFA and OA), salt in the moisture (S/M), and water activity ( a _w ) (based on VC and SA) were highly correlated with PC2, resulted in two distinct groups. Based on lipolysis and glycolysis studies, early‐ripened cheese samples showed lipolysis and lactate metabolism more intensely compared to medium and old‐ripened ones. Based on the data of VC and SA, the samples may be classified into three groups: (1) early‐ripened cheeses with a salty taste, waxy to cheesy odor, and rubbery texture, (2) medium‐ripened cheese with a sweet taste and cheesy odor, and (3) old‐ripened cheese with a bitter taste, cheesy to pungent odor, a firm and fragile texture. Textural attributes were highly correlated with proteolysis indices and pH. The results of sensory desirability indicated a significant correlation with pungency, bitterness, and OAs. The cheese samples ripened on the day 127 were selected as the most desirable product. Ripening time had a significant effect on the chemical composition, especially on S/M, pH, and a _w   parameters, which determine the pattern as well as the intensity of biochemical pathways and the final sensory attributes. Practical Application: The current study intends to characterize and develop a standardized procedure for producing a traditional cheese called “Kope cheese” by determining the appropriate duration time for the ripening process, determining the main chemical/biochemical compounds that are highly correlated with its unique flavor and texture and distinguishing the key processing factors (such as curd salting, pH values during brining) that have to be altered or controlled carefully during the manufacturing process. The data would help cheese manufacturers determine the optimum time of ripening in order to achieve the best flavor and texture attributes in the final product.

TiO₂/ZnO nanocomposites were prepared by the sol-gel method with and without addatives such as carboxy methyl cellulose (CMC), poly(ethylene glycol) (PEG), polyvinylpyrrolidon, (PVP), and hydroxylpropylcellulose (HPC). The characteristics of the prepared TiO₂/ZnO nanocomposites were identified by IR spectra, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) methods. The additives have a significant effect on the particle size distribution and photocatalytic activity of TiO₂/ZnO nanocomposites. The photocatalytic activity of the synthesized nanocomposites was investigated for decolorization of methyl orange (MO) in water under UV-irradiation in a batch reactor and the results showed that the photocatalytic activity of the nanocomposites have been increased by CMC, PEG, PVP, and HPC, respectively. SEM has shown that the particle size distribution of TiO₂/ZnO nanocomposite in the presence of HPC was better than the other samples.