In the present study, an ultrafine grained (UFG) 304L stainless steel with the average grain size of 300 nm was produced by a combination of cold rolling and annealing. Weldability of the UFG sample was studied by Nd: YAG laser welding under different welding conditions. Taguchi experimental design was used to optimize the effect of frequency, welding time, laser current and laser pulse duratio...

As the turbine industries need to manufacture turbine blades made of martensitic stainless steel AISI 420 with high toughness and wear resistance, local laser hardening has become more and more important. In this research, surface of the samples was initially hardened by high-power pulsed laser beam; then, optimum parameters of hardening were calculated and wear resistance of surface hardened s...

Weld area and weld depth/width ratio can be considered to be of the most important geometrical factors in pulsed laser welding. The effects of carbon dioxide and oxygen additions to the argon shielding gas on the weld properties in pulsed laser welding of low carbon steel is investigated. Presence of carbon dioxide and oxygen up to 10 and 15 percent respectively decreases the weld geometrical f...

Background: Hirsutism is defined as the presence of terminalhairs with a male-like pattern in women, due to the increasedlevels of androgens or increased responses of the target organs toandrogens. Facial hirsutism has a negative effect on the quality oflife in female patients. Among the many therapeutic modalitie...

Background: Exposure to ionizing radiation is inevitable. Using of low-level laser therapy (LLLT) stimulates tissue repair and reduces inflammation. The objective of the present study aimed at evaluating the therapeutic efficacy of Helium-Neon (He-Ne) laser in stimulating the reparative processes in the liver of mice after whole body gamma-irradiation (WBγ-I). Materials and Methods: Two hundred...

background and aims. er:yag laser irradiation has been claimed to improve the adhesive properties of dentin; therefore, it has been proposed as an alternative to acid etching. the aim of this in vitro study was to investigate the shear bond strength of an etch-and-rinse adhesive system to dentin surfaces following er:yag laser and/or phosphoric acid etching. materials and methods. the roots of ...

this study is focused on investigating the parameters of laser percussion drilling process of nickel-base super alloy inconel 718 with thickness of 1 mm. fiber laser with the power of 500 watts was used as the laser source. laser pulse frequency, duty cycle, laser power, focal point position, were assumed as the laser drilling process variables. the hole geometry features, i.e. entrance hole di...

Background  Recent investigations show that both proliferation and secretion of macromolecules by cells can be regulated by low level laser therapy (LLLT). The aim of this study was to determine whether LLLT could induce a bio-stimulatory effects on human gingival fibroblasts (HGF3-PI 53). Therefore, the effect of laser irradiation on human gingival cell proliferation and collagen type I gene ...