Showing papers by "Ali Reyhani published in 2015"

Decomposition of ethane molecules at atmospheric pressure using metal assisted laser induced plasma

Abstract: The decomposition of ethane (C2H6) and the subsequent conversion to other hydrocarbons are investigated using a Q-switched (Q-SW) Nd:YAG laser induced plasma inside a controlled chamber. The metal targets, including iron, copper, nickel, and palladium, are employed to assist the plasma formation and ethane decomposition. Fourier transform infrared spectroscopy and gas chromatography are used for identifying and analyzing the products to determine dissociation rates as well. Several C1 and C2 components, namely, methane (CH4), ethylene (C2H4), and acetylene (C2H2), as well as heavier C3, C4, and C5 components, such as propane, butane, and pentane, are obtained after ethane decomposition. The yield, selectivity, and conversion ratios of hydrocarbons mainly depend on the metal species as the active catalysts during laser exposure. The most abundant component is found to be ethylene having a selectivity of ∼39% using a palladium target. This technique offers high reproducibility to generate selective and desired hydrocarbon compounds in the controlled chamber.

Physical and chemical properties of lamb renal capsule irradiated by ArF laser

Abstract: Excimer laser at 193 nm was irradiated on the renal tissues during various exposure times in order to investigate the chemical and physical surface properties using Fourier transform infrared spectroscopy, photo electron spectroscopy, contact angle measurements, and tensile test accordingly. We have shown that ultraviolet laser strongly alters the oxygen content of skin layer that causes changes in the tissue morphology leading to significant skin hydrophilicity.

Magnetic Measurements of Graphene and Defected Graphene Generated by Laser Ablation Method

Abstract: In this paper, the magnetic properties of carbon based material, graphene is studied, which is generated by laser ablation in cryogenic media. Transmission electron microscopy (TEM) and alternating gradient force magnetometer (AGFM) are applied to investigate the graphene morphology and magnetic properties, respectively. The graphene synthesized by the laser ablation method exhibits diamagnetic behavior. However the magnetic transition from diamagnetic to paramagnetic effect is lucidly observed by functionalizing the graphene sample with silver atoms.