Islamic Azad University

About: Islamic Azad University is a education organization based out in Tehran, Iran. It is known for research contribution in the topics: Population & Catalysis. The organization has 83635 authors who have published 113437 publications receiving 1275049 citations. The organization is also known as: Azad University.

Development of a Lower Toxic Approach Based on Green Synthesis of Water-Compatible Molecularly Imprinted Nanoparticles for the Extraction of Hydrochlorothiazide from Human Urine

Abstract: In the present paper, one-pot green syntheses of novel hydrophilic and superparamagnetic molecularly imprinted polymers (MMIPs) for the cleanup and extraction of hydrochlorothiazide (HCT) in human urine are described. The MMIPs were prepared via a sol–gel process using Fe3O4 magnetite as a magnetic component, HCT as a template, tetraethyl orthosilicate (TEOS) as the cross-linker, and 3-aminopropyl trimethoxysilane (APTMS) as the functionalized monomer, which could simplify the imprinting process. During the synthesis process, a surfactant was especially used to graft the silica-imprinted nanoparticles. The key step of this research is mild working temperature without consuming any organic solvent during the synthesis of MMIPs in addition to its ability for efficient and highly selective enrichment of HCT in complicated human urine. The morphology, structure, and magnetic properties of the MMIPs were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier tra...

The Effect of Flow Rate on Morphology and Deposition Area of Electrospun Nylon 6 Nanofiber

Abstract: Electrospinning is a process that produces continuous polymer fibers with diameters of a nanometric scale. Nylon 6 in formic acid was electrospun to obtain the nanofibers. Fibers with different diameters were obtained using flow rates of 0.1, 0.5, 1 and 1.5 mL/hr, 20 wt% solution concentration, with an applied voltage of 20 kV and 15 cm spinning distance. Flow rate influenced the fiber diameter distribution, droplet size and its initiating shape at the capillary tip, the trajectory of the jet, maintenance of Taylor cone, areal density and nanofiber morphology. The morphology of the electrospun nanofibers was analyzed by using the scanning electron microscope (SEM). The effect of flow rate on the deposition area was also investigated for better control of the process. It was observed that a stabilized Taylor cone, small average droplet size, narrowest fiber diameter distribution, more stability in the originating jet, and uniform morphology of nanofiber is obtained at a flow rate of 0.5 mL/hr.

A new image encryption method: parallel sub-image encryption with hyper chaos

Abstract: A new image encryption scheme, based on a total shuffling and parallel encryption algorithm is proposed in this paper. Two chaotic systems have been used in the encryption algorithm to confuse the re- lationship between the plain-image and the cipher- image. To make the encryption procedure more con- fusing and complex, the plain-image is first divided into 4 sub-images and then the position of each sub- image is changed pseudo-randomly according to a lo- gistic map. Next, a total shuffling matrix is used to shuffle the position of pixels in the whole image and then sub-images are encrypted simultaneously in a parallel manner. The experimental results on USC data base demonstrate that the proposed encryption algo- rithm has a low time complexity and has the advan- tages of large key space and high security. Moreover, the robustness of this locally encryption method is much more in contrast with other encryption schemes and the distribution of gray values has a random-like behavior in the encrypted image.