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Because of its special structural and functional characteristics, poly(vinyl chloride)/zinc oxide nanocomposite (PVC/ZnO) exhibits great potential in a variety of electrical, optical, water treatment, and medical applications. According to that, this study was carried out to examine the AC electrical properties of the prepared PVC/ZnO nanocomposite films using the AC impedance techniques. The PVC/ZnO nanocomposite films were prepared by casting method by weight% concentrations of 2.5, 5.0, 7.5 and 10.0% ZnO nanoparticle. Each mixture was fabricated in film and casted in 5 cm × 5 cm glass caste. Fourier transform infrared (FTIR) spectroscopy, x‐ray diffraction (XRD), and scanning electron microscopy (SEM) were used to characterize the nanocomposites samples. The results of the FTIR spectroscopy analysis of the PVC/ZnO nanocomposites confirmed the presence of peaks characteristic of the vibration of the ZnO bond. XRD revealed that pure PVC films are partially crystalline with hallow peak but ZnO nanoparticles have wurtzite structure, and the nanocomposite films were almost the same as those of ZnO with decrease in the degree of crystallization, causing increase in the amorphous region. The surface of the films was analyzed by SEM, which becomes rough with some small aggregates compared with pure PVC with good distribution in the entire surface region with bright spots. The electrical properties AC conductivity (σAc), real dielectric constant (∈′), imaginary dielectric constant (∈″), real electrical modulus (M′), and imaginary electric modulus (M″) were studied in the frequency range 2–6 MHz and temperature range 293–313 K for the prepared film studied. The results showed that the properties of the PVC/ZnO nanocomposite films were found to be dependent on the frequency, and the concentration of the ZnO nanoparticle in the PVC polymer matrix. In addition, the results of the study show that there is a sharp increase in the σAc, with increasing of temperature. In contrast, the other parameters, that is, ∈′, ∈″, M′, and M″ are temperature independence. Highlights: PVC/ZnO nanocomposite films with different weight% concentrations of ZnO nanoparticle were prepared.AC electrical properties were measured using AC impedance techniques.The nanocomposites samples were characterized using FTIR, XRD, and SEM.Electrical properties σAc, ∈′, ∈″, M′, and M″ were found to be frequency and temperature dependences. [ABSTRACT FROM AUTHOR]

This work studies the direct current breakdown characteristics of unfilled epoxy and epoxy nonconductive nanocomposites ( S i O 2 , M g O and A l 2 O 3 ). It also examines the variation of electrical properties in epoxy nanocomposites. The novel aspect of this study is that the samples of Epoxy nanocomposite were exposed to high voltages of up to six kilo volts for three hours using field electron microscopy under high vacuum conditions ( 10 − 5 mbar). The current emitted from these samples was measured at three different intervals of time. In addition, the influence of high voltage on the permittivity, loss factor (tan(δ)), and conductivity of the epoxy nanocomposite was studied. This evaluation was conducted before and after applying the voltage at room temperature, The frequency range extends from 10 − 2 – 10 − 7 Hz using the Novo Control Alpha-A analyzer. Current–voltage characterization was performed through field electron microscopy. The samples were characterized by scanning electron microscopy–energy dispersive X-ray spectroscopy and Fourier Transform Infrared Spectroscopy. The unfilled epoxy exhibited structural degradation, resulting in the formation of holes when exposed to high voltages of up to six kilo volts, leading to a reduction in electrical properties. Nevertheless, the addition of nanoparticles shows a significant increase in the operational lifetime of the epoxy nanocomposite. The degree of increase in the lifetime of epoxy composite varied depending on several factors such as the type of NPs introduced and their respective sizes. The epoxy/ A l 2 O 3 nanocomposite comparing with epoxy/MgO and epoxy/ S i O 2 nanocomposite showed elevated resistance to direct current breakdown strength and maintaining its dielectric. [ABSTRACT FROM AUTHOR]

Summary: Doping titanium's ions on perovskite‐type oxides as VTixSc1−xO3; changes the semi‐conducting behavior as well as magnetic, optical, and thermoelectric properties of VScO3 pervoskites. Doping titanium ions with different concentrations (x = 0.25, 0.5, 0.75, and 1) is investigated through the density functional theory (DFT) by the full potential linearized augmented plane wave (FP‐LAPW) technique using GGA‐mBJ potentials. All doped structures show semiconductor behavior in spin down channel, while the original structure VScO3 shows the same behavior in spin up channel. The values of energy band gap changes according the doped ions concentration Ti. The total spin magnetic moment increases as the concentration of Ti increases; the optical properties show a remarkable change during doping processes. The requirements for elastic‐stability of crystal lattices are applied. All studied structures are mechanically stable, high value of the temperature of melting (Tm), and Debye temperature for VSc1−xTixO3 compounds is higher than 400°K, besides the high values of Young's modulus and bulk modulus all are implying the hardness of the perovskite. Calculated energy band structure by WIEN2k is utilized to calculate the transport coefficients by using the semi‐classical Boltzmann transport theory depends on the constant relaxation time (τ) employed in the BoltzTraP package. Thermoelectric properties for all compounds are calculated and indicated that these compounds may be used in thermoelectric applications. [ABSTRACT FROM AUTHOR]

The present study aimed to investigate the effect of silver nanoparticles (AgNPs) (50 mg/L) on the behavioral changes, biochemical alterations, oxidative stress and the histopathological changes in liver tissues of African catfish, clarias gariepinus. In addition to the potential role of Nigella sativa (NS) in ameliorating these effects. Fish were divided into four groups: group 1 was control fed on basal diet, group 2 was fed on 3% (NS) of basal diet, group 3 was exposed to 50 mg/L AgNPs, and group 4 was exposed to 50 mg/L AgNPs and fed on 3% (NS) for 30 days. Results revealed that catfish in group (3) exposed to AgNPs exhibited changes in skin pigmentation and abnormal behavior in swim. A significant elevation (P<0.05) in levels of alkaline phosphatase (ALP), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) of catfish exposed to AgNPs compared to the control fish. Furthermore, marked increase of hepatic lipid peroxidation (LPO), catalase (CAT), total antioxidant (TAC), glutathione (GSH), and superoxide dismutase (SOD) levels were recorded in group (3). Alternatively, feding exposed catfish to AgNPs on 3% (NS) for 30 days, decreased the levels of ALP, AST, and ALT, improved the oxidative damage in liver tissues, and attenuated the histological changes in hepatic tissues of C. gariepinus (group 4). Hence, this study suggested that (NS) has hepatoprotective and antioxidant effects in African catfish against AgNPs toxicity. [ABSTRACT FROM AUTHOR]

The examined fish intoxicated with aflatoxin B1 (AFB1) showed several non-specific signs, including inadequate growth, significant losses in aquaculture industry especially resulting from aflatoxicosis. The study using Zinc oxide (ZnO) and Hematite (α-Fe2O3) nanoparticles (NPs) to assess the effect of using as on their own negative impacts of AFB1 3 ppm/Kg for 13 weeks was studied 360 healthy fingerlings of Nile tilapia, were divided into eight groups (15 fish/group) with three replicates, it has been applied in 24 aquariums. Group1 (G1) fed only a basal diet as control. While, G2, G3, and G4 were fed on diets supplemented with 2 g/kg diet of ZnO NPs, Hematite NPs and combination of both respectively. Group5 (G5) was fed on diets contamination with AFB1 (3 ppm/kg diet), while G6, G7 and G8 were fed on diets containing 2 g/kg diet of (ZnO NPs, Hematite NPs and combination of both) plus AFB1 (3 ppm/kg diet) respectively. Experimental treatments affected significantly on the Final Body Weight (FBW), Daily Gain (DG), Feed Conversion Ratio (FCR) and mortality Table (1, 2(. FBW and DG reduced to 37.856 g and 0.227 g in fish feed containing AFB1, when compared with groups AFB1 which supported with feed additives (ZnO, Hematite and combination of both) NPs, which reported final body weight 45.507, 47.007, 49.762 g and daily gain 0.313, 0.328, 0.360 g respectively. The highest FBW and DG were determined in group treated with feed additives combination of (ZnO and Hematite) nanoparticles, keep it track of by the fish group fed diet supplemented with Hematite NPs then those fed diet supplemented with ZnO NPs and the recorded values were for final body weight 55.857, 61.500, 63.874 g daily gain 0.427, 0.488, 0.515 g respectively than that of the control group G1 52.784, g FBW and 0.393 g DG. The highest survival rate was obtained in fish group treated with combination of (ZnO and Hematite) nanoparticles, The survival rate was (95.556 %) in fish fed diets combination of (ZnO and Hematite) NPs, while it was 57.778 % in fish group G5 fed AFB1, which enhanced in aflatoxicated group G8 which supplemented with combination of (ZnO and Hematite) NPs 84.444 %, and in aflatoxicated group G7 which supplemented with Hematite NPs 77.778%, and in aflatoxicated group G6 which supplemented with ZnO NPs 75.556%. The best FCR was obtained in same order in fish group treated with combination of ZnO NPs and Hematite NPs, Hematite NPs then ZnO NPs 1.187, 1.170, 1.253 compared to the control group which recorded 1.462. On the other hand, aflatoxicated groups significantly affected feed conversion impaired significantly affected, aflatoxicated group recorded 1.950 but when supported with ZnO NPs, Hematite NPs and combination of both recorded 1.541, 1.525 and 1.502 respectively. [ABSTRACT FROM AUTHOR]

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Polymer membranes of ferrites nanoparticles, glycerol, and poly(vinyl alcohol) (PVA) were fabricated using a solution casting method. Spinel ferrites nanoparticles, CuFe2O4 or ZnFe2O4, and glycerol were used as dopants to control the membranes' electrical conductivity. The morphology, composition, and interaction between PVA and the dopants were investigated byscanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differentialscanning calorimeter (DSC), and thermal gravimetric analysis (TGA). Electrical characterization of the membranes was conducted by impedance spectroscopy using frequencies between 1 and 106 Hz and variable temperatures. The results revealed a negative temperature coefficient of the resistance of the membranes. Additionally, membranes with ZnFe2O4 nanoparticles exhibit higher electrical impedance than those with CuFe2O4 nanoparticles. Therefore, electrical conductivity could be controlled using a suitable dopant's composition and concentration. The membranes presented in this study exhibit semiconducting properties, thus, they have potentials to be utilized in multiple applications including the flexible organic‐based device. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48821. [ABSTRACT FROM AUTHOR]