s. baghshahi

In this research, the effect of addition of silicon carbide (SiC) nanoparticles on the improvement of the structural, superconductivity, magnetic, and flux pinning properties of high-temperature superconductor Bi1.6Pb0.4Sr2Ca2Cu3O10+θ (Bi-2223) was investigated. The Bi-2223 ceramic superconductor was prepared using the sol-gel method, and silicon carbide nanoparticles were modified by Azobisisobutyronitrile (AIBN). The X-ray diffractometry, feild emission scanning electron microscopy, magnetic susceptibility, and hystersis loop measurements were performed to characterize the synthesized compounds. Based on the magnetic measurements, the superconductivity transition temperature dropped with an increase in the content of nanoparticles. Also, the maximum magnetization, hysteresis loop width, critical current density, and magnetic flux pinning force belonged to the sample with 0.4 wt.% SiC nanoparticles.

In this research, the influence of titanium dioxide nanoparticles on the structural and magnetic properties of high-temperature superconductor Bi1.6Pb0.4Sr2Ca2Cu3O10+θ (Bi-2223) from the Bi-based ceramic system  (BSCCO) was studied. In order to investigate the synthesized samples, X-ray diffractometry and magnetic measurements were performed. Based on the magnetic measurements, the superconductivity transition temperature declined with the increase in the nanoparticleschr('39') content. The addition of nanoparticles affected on the hysteresis loop width. Accordingly, the compound containing 0.2 wt.% nanoparticles had the maximum magnetization,  hysteresis loop width, and critical current density.

Recent advances in the biological sciences have become particularly important because they are the basis for some related sciences such as agriculture, medicine, pharmacology, biotechnology, and even bionanotechnology. In this study, the effect of different salinity treatments (0, 50, 100, and 150 µM) on Hyssopus officinalis L. and the properties of silver nanoparticles) Ag NPs) biosynthesized using these under-salinity stress plants leaves extract were investigated. The color change of the solutions, surface plasmon resonance at 450 nm and X-ray diffraction pattern confirmed the biosynthesis of Ag NPs. Field emission scanning electron microscopy (FESEM) images showed that most of the nanoparticles were spherical, with few angular shapes visible in 50 and 100 µM treatments. Fourier-transform infrared spectroscopy (FTIR) results revealed the participant functional groups of the plant extract in the biosynthesis process such as OH, CO, =CH and C=C. The 50 µM salinity treatment had the highest effect on increasing plant metabolites. The smallest nanoparticles (25.3 nm and spherical) were related to the control treatment. Some nanoparticles biosynthesized using the extract obtained from 150 µM salinity treatment were angular in shape with 34.2 nm in size and showed the highest antibacterial properties. Gram-negative bacteria were more sensitive to Ag NPs than the gram-positive ones. These results, following our previous research, revealed for the first time the effect of salinity treatments on the properties of Ag NPs biosynthesized using hyssop extract. The present results can provide an interesting background for Ag NPs biosynthesis that can be a good alternative to antibiotics.

Overusing nitrogen fertilizer causes some serious problems for water resources, soil, and agriculture products. Researchers have been trying to develop effective means which may use less amount of fertilizers containing nitrogen. In this work, cost-effective ceramic granule adsorbent was prepared to be used as a fertilizer carrier of controlled release behavior. A mixture of 70 wt.% domestic kaolin and 30 wt.% gibbsite was used to produce the granules. By utilizing thermal analysis of raw granule, the calcination temperatures were obtained and the effect of various calcination temperatures of 500, 600, and 700˚C on the water adsorption was studied. The characteristics of granules were investigated by XRD, BET, FTIR, and SEM analyses. The results showed that by increasing the calcination temperature, the crystal structure of the granules was transformed into a dehydrated form and by calcination at 600°C the specific surface area of granules increased from 7.50 to 53.45m2/g. The granules were soaked in a 500g/lit solution of urea, where they adsorbed about 10wt.% urea. The dried urea-loaded granules were placed in water where the release of urea was measured by UV-vis spectrophotometry. Finally, different portions of urea-loaded granules were evaluated as fertilizer in the growing bed of corn plant where the height and the stem diameter of samples were compared with a control sample as well as a sample fertilized by urea directly. The results showed that by using the loaded granules, the urea consumption can be reduced by 50%.