Abstract Welding round bars of large diameters in a rotational laser beam welding process corresponds with weld pool bulging and the risk defects. Power modulation is promising approach for bulge reduction keyhole stabilisation to achieve superior quality. The following investigations are about specific effects power diameter 30 mm. speed 0.95 m/min argon used as shielding gas. Triangle shaped ...

hartree-fock (hf) and density functional theory (dft) methods employed to study the effect of conformational change on the 13c chemical shifts of 6-mono axial and equatorial substituted and 6,7-di axial-axial, equatorial-equatorial and axial-equatorial substitutedderivatives of 5,6,7,8-tetrahydrodibenzo[a,c]cyclo-octene. the geometry of the conformers have been optimized in the gas phase employ...

Gerda, the GERmanium Detector Array experiment, is a new double beta-decay experiment which is currently under construction in the INFN National Gran Sasso Laboratory (Lngs), Italy. It is implementing a new shielding concept by operating bare Ge diodes enriched in Ge-76 in high purity liquid argon supplemented by a water shield. The aim of Gerda is to verify or refute the recent claim of discov...

The model of a DC glow discharge with metastable argon atoms and dust particles based on the Boltzmann equation for the electron energy distribution function (EEDF), dust particle charging, and balance equation for metastable argon atoms is presented. The processes of direct and stepwise electron impact ionization, metastable-metastable collisions, and recombination of electrons and ions on the...

The feasibility of using a photoionized, low-ionization potential organic seed gas to initiate a high pressure plasma discharge is examined and compared to radio frequency breakdown of high pressure argon alone. The seed gas, tetrakis~dimethylamino!ethylene, which has an ionization potential of 6.1 eV is ionized by an ultraviolet laser through 6.4 eV photon absorption, and forms a plasma column...

We report on the measurement of the specific activity of Ar in natural argon. The measurement was performed with a 2.3-liter two-phase (liquid and gas) argon drift chamber. The detector was developed by the WARP Collaboration as a prototype detector for WIMP Dark Matter searches with argon as a target. The detector was operated for more than two years at Laboratori Nazionali del Gran Sasso, Ita...

The performance of a new pulsed arc cluster ion source (PACIS) is demonstrated for pure metal cluster ions and anions as well as mixed metal-rare-gas clusters. Pure metal clusters like W$ exhibit intensity distributions similar to those from laser vaporization sources. The ion current of the PACIS is comparable to that of a laser vaporization source. For metal-doped argon cluster ions, a single...