Effects of Cu dilution in IrMn on the exchange bias of CoFe/IrMn bilayers

The effect of nonmagnetic dilution in metallic antiferromagnets (AFMs) on the exchange bias (EB) has been investigated from a structural, magnetic, and Monte Carlo simulation point of view in bilayers of CoFe/(IrMn)1-xCux. Dilution by Cu atoms throughout the volume of the AFM IrMn gives rise to an enhanced EB field (HEB) for 5 K相似文献   

Solubility and solution thermodynamics of 2, 6-bis (4-hydroybenzylidene) cyclohexanone in pure and binary solvents at various temperatures

Solubility of 2, 6-bis (4-hydroxybenzylidene) cyclohexanone (BHBC) in pure solvents such as 1,4-dioxane, methanol, 1-butanol, 1-propanol, ethyl acetate, acetone, tetrahydrofuran (THF), glacial acetic acid, dimethyl sulphoxide (DMSO) and binary solvents dimethyl formamide (DMF) and (1-Propanol + Tetrahydrofuran) were investigated by gravimetric method at different temperature range. The experiment solubility increases with increase in temperature in both pure and binary solvents. The Maximum solubility is found in DMF at 328.15 K and for binary solvent mixture i.e. 1-propanol and THF (0.9 mol fraction) it was maximum at 318.15 K. Further modified Apelblate and Buchowski-Ksiazczak models were used for the theoretical calculation of solubility of BHBC in pure as well binary solvents. A satisfactory correlation of these models with experimental data was observed. The solution thermodynamics parameters like enthalpies, Gibb's free energy of dissolution and entropy of solutions were calculated using Van't Hoff and Gibb's equation, which reveals the solvation mechanism is non-spontaneous and entropy driven.     

Self-assembled geometric liquid-crystalline nanoparticles imaged in three dimensions: hexosomes are not necessarily flat hexagonal prisms

Attempts to understand the complex 3D morphology of non-lamellar liquid-crystalline nanostructured particles, formed by the dispersion of a reversed hexagonal phase (hexosomes) and bicontinuous cubic phase (cubosomes) in water, have been limited by the lack of suitable 3D imaging techniques. Using cryo-field emission scanning electron microscopy, we show that whereas the structure of cubosomes generally reflects that anticipated from modeling approaches, hexosomes, which were previously proposed to be flat hexagonal prisms, in fact often possess a "spinning-top-like" structure, which is likely to influence their interactions with surfaces.     

Development and validation of the HPLC method for the analysis of trimetazidine hydrochloride in bulk drug and pharmaceutical dosage forms

A simple, economic, selective, precise, and accurate high-performance liquid chromatographic (HPLC) method for the analysis of trimetazidine hydrochloride in both bulk drug and pharmaceutical formulations was developed and validated in the present study. The mobile phase consisted of water: methanol: triethylamine (75: 25: 0.1 v/v/v), and pH 3.3 was adjusted with orthophosphoric acid. This system was found to give a sharp peak of trimetazidine hydrochloride at a retention time of 3.375 ± 0.04 min. HPLC analysis of trimetazidine hydrochloride was carried out at a wavelength of 232 nm with a flow rate of 1.0 mL/min. The linear regression analysis data for the calibration curve showed a good linear relationship with a regression coefficient of 0.997 in the concentration range of 5–90 μg/mL. The linear regression equation was y = 35362x − 8964.2. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 3.6 and 10.9 μg/mL, respectively. The developed method was employed with a high degree of precision and accuracy for the analysis of trimetazidine hydrochloride. The developed method was validated for accuracy, precision, robustness, detection, and quantification limits as per the ICH guidelines. The wide linearity range, accuracy, sensitivity, short retention time, and composition of the mobile phase indicated that this method is better for the quantification of trimetazidine hydrochloride. The text was submitted by the authors in English.     

The effect of UV radiation on the thermal degradation of cellulose triacetate

The effect of UV radiation on the thermal degradation of cellulose triacetate (CTA) has been investigated. Simultaneous thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) have been performed on CTA samples of 0.25 mm thickness. These samples were exposed to different energy fluences of UV in the range 2.3–113 kJ/cm². The specific heat capacity, C_p, has been evaluated for unexposed and exposed CTA samples using DSC method. The results indicate that the transition temperatures, onset temperatures of evaporation, specific heat capacity and the thermal activation energy of decomposition, E_a are affected by the UV energy fluence owing to the simultaneous processes of degradation and crosslinking.     

Quantitative Estimation of Protein in Sprouts of Vigna radiate (Mung Beans), Lens culinaris (Lentils), and Cicer arietinum (Chickpeas) by Kjeldahl and Lowry Methods

Protein scarcity is the most vital cause of long-lasting diseases and even untimely deaths in some developing nations. The application of protein in food is advantageous from the point of view of non-toxicity, biocompatibility, and dietary benefits. This study aimed to determine the protein contents of the sprouts of Vigna radiates (mung beans), Lens culinaris (lentils), and Cicer arietinum (chickpeas) using the Kjeldahl and Lowry methods. The results obtained from the Kjeldahl method identified protein concentrations of 2.54, 2.63, and 2.19%, whereas the Lowry method results identified protein concentrations of 2.96%, 4.10%, and 1.6% in mung beans, lentils, and chickpeas, respectively. In both the methods, lentils were found to have the highest amount of protein followed by mung beans and chickpeas. Both the Kjeldahl and Lowry methods demonstrated good protein values and low variation in the protein amount in the analyzed samples. Furthermore, the methods had greater sensitivity and comparable experimental variability. The outcomes revealed that assays can be applied for protein analysis in legumes. In the context of a lack of suitable standard procedures for evaluating legumes’ compositions, the present study is suitable for food control laboratories. In addition, the studied samples represent a significant source of protein and can be used to fulfil the daily requirements for protein intake and other food applications.     

Study on the Synthesis of ZnO Nanoparticles Using Azadirachta indica Extracts for the Fabrication of a Gas Sensor

This paper compared the effects of A. indica plant proteins over chemical methods in the morphology of zinc oxide nanoparticles (ZnO NPs) prepared by a co-precipitation method, and ethanol sensing performance of prepared thin films deposited over a fluorene-doped tin oxide (FTO) bind glass substrate using spray pyrolysis technique. The average crystallite sizes and diameters of the grain-sized cluster ZnO NPs were 25 and (701.79 ± 176.21) nm for an undoped sample and 20 and (489.99 ± 112.96) nm for A. india dye-doped sample. The fourier transform infrared spectroscopy (FTIR) analysis confirmed the formation of the Zn–O bond at 450 cm⁻¹, and also showed the presence of plant proteins due to A. indica dye extracts. ZnO NPs films exhibited good response (up to 51 and 72% for without and with A. indica dye-doped extracts, respectively) toward ethanol vapors with quick response-recovery characteristics at a temperature of 250 °C for undoped and 225 °C for A. indica dye-doped ZnO thin films. The interaction of A. indica dye extracts helps to decrease the operating temperature and increased the response and recovery rates of the sensor, which may be due to an increase in the specific surface area, resulting in adsorption of more oxygen and hence high response results.     

Characterization and Evaluation of Antimicrobial Potential of Trigonella incise (Linn) Mediated Biosynthesized Silver Nanoparticles

The goal of the research was to explore a new green method used to synthesize silver nanoparticles (Ag NPs) from an aqueous extract of Trigonella incise, which serves as a reducing and stabilizing agent. The obtained results showed an 85% yield of nanoparticles by using 2:5 (v/v) of 5% plant extract with a 0.5 M solution of AgNO₃. Different techniques were used to characterize the synthesized Ag NPs, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and UV–visible spectroscopy. The UV–visible spectra of green synthesized silver nanoparticles showed maximum absorption at a wavelength of 440 nm. The FT-IR studies revealed the stretching oscillation frequency of synthesized silver nanoparticles in the absorption band near 860 cm⁻¹. Similarly, the bending and stretching oscillation frequencies of the NH function group were assigned to the band in the 3226 cm⁻¹ and 1647 cm⁻¹ regions. The bending vibration of C-O at 1159 cm⁻¹ confirmed the carbonyl functional group that was also assigned to the small intensity band in the range of 2361 cm⁻¹. The X-ray diffraction analysis of Ag NPs revealed four distinct diffraction peaks at 2θ of 38°, 45°, 65° and 78°, corresponds to (111), (200), (220) and (311) of the face-centered cubic shape. The round shape morphology of Ag NPs with a mean diameter in the range 20–80 nm was analyzed via SEM images. Furthermore, the nanoparticles showed more significant antimicrobial activity against Salmonella typhi (S. typhi) and Staphylococcus aureus (S. aureus) with an inhibition zone of 21.5 mm and 20.5 mm at 6 μg/mL concentrations, respectively, once compared to the standard reference. At concentrations of 2 µg/mL and 4 µg/mL, all of the bacterial strains showed moderate activity, with inhibition zones ranging from 11 mm to 18.5 mm. Even at high concentrations of AgNPs, S. typhi showed maximum resistance. The best antifungal activity was observed by synthesized Ag NPs against Candida albicans (C. albicans) with 21 mm zone of inhibition, as compared to a standard drug which gives 22 mm of inhibition. Therefore, we conclude that the antibacterial and antifungal activities showed satisfactory results from the synthesized Ag NPs.     

Heat transfer analysis of micropolar hybrid nanofluid over an oscillating vertical plate and Newtonian heating

Journal of Thermal Analysis and Calorimetry - The unsteady flow of micropolar hybrid nanofluids through an oscillating vertical plate having infinite length has been analyzed in this study. This...