Austenitic stainless steel SS304 grade was welded with active Tungsten Inert Gas (TIG) welding process by applying a flux paste made of SiO2 powder and acetone. SiO2 flux application improves the weld bead depth with a simultaneous reduction in weld bead width. The improvement in penetration results from arc constriction and reversal of Marangoni convection. Experimental studies revealed that t...

Synapse formation requires the organization of presynaptic active zones, the synaptic vesicle release sites, in precise apposition to postsynaptic neurotransmitter receptor clusters; however, the molecular mechanisms responsible for these processes remain unclear. Here, we show that P/Q-type and N-type voltage-dependent calcium channels (VDCCs) play essential roles as scaffolding proteins in th...

Cytokinesis in animal cells results from the assembly and constriction of a circumferential array of actin filaments and myosin-2. Microtubules of the mitotic apparatus determine the position at which the cytokinetic actomyosin array forms, but the molecular mechanisms by which they do so remain unknown. The small GTPase RhoA has previously been implicated in cytokinesis. Using four-dimensional...

sarcheshmeh porphyry copper deposit is located 65 km southwest of rafsanjan in kerman province. the sarcheshmeh deposit belongs to the southeastern part of urumieh-dokhtar magmatic assemblage (i.e., dehaj-sarduyeh zone). intrusion of sarcheshmeh granodiorite stock in faulted and thrusted early-tertiary volcano-sedimentary deposits, led to mineralization in miocene. in this research, the mass ch...

Bagh Vang Section is located at about 45 km to the Northwest of Tabas and South of Shirgesht areas. In Bagh Vang Section, the Permian deposits of the Jamal Formation with a thickness of 270 m are underlain by the Sardar Formation disconformably. The formation is also transitionally and conformably overlain by Lower Triassic deposits of Sorkh Shale Formation. A total of 124 rock samples have bee...

An experimental investigation of one-dimensional, diffusion-limited A + B ~ C chemical reactions is reported. The persistence of reactant segregation and the formation of a depletion zone is observed and expressed in terms of the universal time exponents: c~ (motion of the boundary zone), fl (width of instantaneous product formation zone), 7 (rate of instantaneous local formation of product), c...

a sequence of permian rocks crops out in northwest of khur in central alborz, north of iran. this sequence consists of the dorud (asselian-sakmarian), ruteh (artinskian-murgabian) and nesen (early djulfian) formations. the ruteh and nesen formations in alborz range were deposited in a shallow marine environment of the continental margin in the paleo-tethys. the ruteh formation with a thickness ...

Copper matrix composite reinforced by 1wt.% TiB2 particles was prepared using in situ reaction of Cu-1.4wt.% Ti and Cu-0.7wt.% B by rapid solidification and subsequent heat treatment for 1-20 hrs at 900ºC. High-resolution transmission electron microscopy (HRTEM) characterization showed that primary TiB2 particles were formed in liquid copper. Heat treatment of as-solidified samples led to ...