![]() Leaching Studies for Copper and Solder Alloy Recovery from Shredded Particles of Waste Printed Circuit Boards Serious dissolution due to electrochemical reaction and a thick, porous PbSO4 surface layer are observed in acidified soil, suggesting more severe toxicity potential of Pb in soil rather than in water. Surface product analysis reveals the slight damage of SnPb in saline soil. Evidence for the significantly preferential release of Sn into the leachate is provided the galvanic couple accelerated such preferential release. The amounts of Sn and Pb elements leached, when subjected to acidic soil, are higher than those with saline soil. The leaching behaviour of Sn and Pb elements from eutectic SnPb solder of electronic waste in acidic soil was investigated through acidification with HCl-H2SO4 solution and compared with saline solution. Lao, Xiaodong Cheng, Congqian Min, Xiaohua Zhao, Jie Zhou, Dayu Li, Xiaogang Leaching behaviour and environmental risk assessment of heavy metals from electronic solder in acidified soil. Laser welding was the only joining process well tolerated by all tested cells. The joint produced by electrical resistance welding was well tolerated by both osteoblasts and fibroblasts, whereas traditional soldering caused a significant (P < 0.05) decrease in both osteoblast ALP activity and fibroblast viability, and prevented the growth of keratinocytes in vitro. Chromium strongly affected fibroblast growth. The high nickel and chromium content of orthodontic wires damaged both osteoblasts and fibroblasts, but did not affect keratinocytes. Segments of each wire, cut into different lengths, were added to each well in which the cells were grown to confluence. ![]() Nickel and chromium, known as possible toxic metals, were also examined using pure nickel- and chromium-plated titanium wires. Two types of commercially available wires normally used for orthodontic appliances, with a similar chemical composition (iron, carbon, silicon, chromium, molybdenum, phosphorus, sulphur, vanadium, and nitrogen) but differing in nickel and manganese content, were examined, as well as the joints obtained by electrical resistance welding, traditional soldering, and laser welding. The effects of cell behaviour of metal wires on osteoblast differentiation, expressed by alkaline phosphatase (ALP) activity on fibroblast proliferation, assayed by the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulphophenil)-2H-tetrazolium-phenazine ethosulphate method and on keratinocyte viability and migration on the wires, observed by scanning electron microscopy (SEM), were tested. A method for determining the effects of various types of soldering and welding, both of which in turn could lead to leaching of metal ions, on the growth of osteoblasts, fibroblasts, and oral keratinocytes in vitro, is proposed. The long-term effects of orthodontic appliances in the oral environment and the subsequent leaching of metals are relatively unknown. Sestini, Silvia Notarantonio, Laura Cerboni, Barbara Alessandrini, Carlo Fimiani, Michele Nannelli, Pietro Pelagalli, Antonio Giorgetti, Roberto In vitro toxicity evaluation of silver soldering, electrical resistance, and laser welding of orthodontic wires. Mating of male and female connectors solders each lead to individual cup pin. Multiple resistance soldering device for attaching electric leads to multiple terminal block connectors uses power source with one terminal connected to working probe, and other terminal attached to connector carrying common pins for lead insertion. A simple, efficient resistance soldering apparatus
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |