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 & Adsorption. The organization has 83635 authors who have published 113437 publications receiving 1275049 citations. The organization is also known as: Azad University.

Green synthesis of silver/montmorillonite/chitosan bionanocomposites using the UV irradiation method and evaluation of antibacterial activity

Abstract: In this study, silver nanoparticles (Ag-NPs) were synthesized using a green physical synthetic route into the lamellar space of montmorillonite (MMT)/chitosan (Cts) utilizing the ultraviolet (UV) irradiation reduction method in the absence of any reducing agent or heat treatment. Cts, MMT, and AgNO3 were used as the natural polymeric stabilizer, solid support, and silver precursor, respectively. The properties of Ag/MMT/Cts bionanocomposites (BNCs) were studied as the function of UV irradiation times. UV irradiation disintegrated the Ag-NPs into smaller sizes until a relatively stable size and size distribution were achieved. Meanwhile, the crystalline structure and d-spacing of the MMT interlayer, average size and size distribution, surface morphology, elemental signal peaks, functional groups, and surface plasmon resonance of Ag/MMT/Cts BNCs were determined by powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray fluorescence, Fourier transform infrared, and UV-visible spectroscopy. The antibacterial activity of Ag-NPs in MMT/Cts was investigated against Gram-positive bacteria, ie, Staphylococcus aureus and methicillin-resistant S. aureus and Gram-negative bacteria (ie, Escherichia coli) by the disk diffusion method on Muller–Hinton Agar at different sizes of Ag-NPs. All of the synthesized Ag/MMT/Cts BNCs were found to have high antibacterial activity. These results show that Ag/MMT/Cts BNCs can be useful in different biologic research and biomedical applications, such as surgical devices and drug delivery vehicles.

Nanocrystalline Ce-doped copper ferrite: synthesis, characterization, and its photocatalyst application

Abstract: In the current study and attempt is made to synthesized the cerium-doped copper ferrite nanoparticles (CuFe2−xCexO4) through an auto-combustion method with the aid of nitrate precursors such as copper(II), iron(III), and cerium(III (in an aqueous solution. Besides, the effect of different concentrations of various type of capping agents such as lactose and glucose on the morphology and particle size of final products was investigated. The structural, morphological, and optical properties of as-obtained products were characterized extensively by techniques such as FT-IR, XRD, EDX, SEM, TEM, and UV–vis. Furthermore, the magnetic property of as-prepared CuFe2−xCexO4 nanoparticles was also investigated with vibrating sample magnetometer at room temperature. Moreover, the as-prepared Ce-doped CuFe2O4 nanoparticles were used as efficient photocatalyst for the photocatalytic degradation of harmful organic dye, i.e. methyl orange under ultraviolet light.

The effects of minimal length and maximal momentum on the transition rate of ultra cold neutrons in gravitational field

Abstract: The existence of a minimum observable length and/or a maximum observable momentum is in agreement with various candidates of quantum gravity such as string theory, loop quantum gravity, doubly special relativity and black hole physics. In this scenario, the Heisenberg uncertainty principle is changed to the so-called Generalized (Gravitational) Uncertainty Principle (GUP) which results in modification of all Hamiltonians in quantum mechanics. In this paper, following a recently proposed GUP which is consistent with quantum gravity theories, we study the quantum mechanical systems in the presence of both a minimum length and a maximum momentum. The generalized Hamiltonian contains two additional terms which are proportional to αp3 and α2p4 where α ∼ 1/MPlc is the GUP parameter. For the case of a quantum bouncer, we solve the generalized Schrodinger equation in the momentum space and find the modified energy eigenvalues and eigenfunctions up to the second-order in GUP parameter. The effects of the GUP on the transition rate of ultra cold neutrons in gravitational spectrometers are discussed finally.