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Conventional bending methods require high strength tools to bend the components and these methods are also associated with defects such as spring back, wrinkling instability, wall thinning and distortions at the cross-section. Laser bending offers precision and control and prevents defects associated with traditional bending methods. The present paper examines the effect of laser processing parameters on the bending and vibration characteristics of 304 stainless steel tube. A three-dimensional (3-D) coupled thermo-mechanical finite element (FE) model of the 304 stainless steel was developed using ABAQUS software to simulate the laser-based tube bending process. The process parameters such as laser power from 100 to 400 W and number of laser scans from 2 to 8 are considered. The simulation results showed that the bending angle increases with increasing laser power and the laser passes. In contrast, increasing laser power and laser scans resulted in a small increase in the natural frequency of the laser bent 304 stainless steel. Among the five modes of vibration, the fifth mode produced the highest natural frequency, with an average value of 9942.65 Hz. [ABSTRACT FROM AUTHOR]

The present paper deals with the synthesis of novel macrocyclic complexes of the type [MLX]X, where [(M = Co(II) (1), and Ni(II) (2) X = (Cl2)]. The complexes are synthesized by the reaction of ligand(L)diquinolineno[1,3,7,9]tetraazacyclododecine-7,15-ethane(14H,16H)-benzene with the corresponding metal salts. The synthesized complexes are thoroughly characterized by elemental analysis, FT-IR, 1H-NMR, Mass and electronic spectra. The complexes (1) and (2) were evaluated for in vitro cytotoxicity against human breast adenocarcinoma cell (MCF-7). MTT cytotoxicity studies shows both the complexes are most effective. The binding properties of these complexes with calf thymus-DNA were studied by absorption, emission spectra, viscosity measurements, and thermal denaturation studies. On binding to CT-DNA, the absorption spectrum undergoes bathochromic and hypochromic shifts. The absorption spectral results indicate that the intrinsic binding constant (Kb) are 4.8 × 105 M−1 for (1) and 3.9 × 105 M−1 for (2) respectively, suggesting that complex (1) binds more strongly to CT-DNA than complex (2). The viscosity measurement results revealed the viscosity of sonicated rod like DNA fragments increased when the complex was added to the solution of CT-DNA. The synthesized ligand and its metal complexes are screened for antibacterial and antifungal activities. [ABSTRACT FROM AUTHOR]