Automatic welding technology for vertical welds of 9%Ni steel plates for inner LNG storage tanks

Shielded Metal Arc Welding (SMAW) is always used for the vertical welding of inner wall of LNG storage tanks in China, and there has been no successful case for the application of automatic welding technology to vertical welding so far. In this paper, an automatic Flux Cored Arc Welding (FCAW) technology with multi-layer, filament, short arc, circumferential swing and short pause on both sides of the groove was proposed through the automatic welding test of vertical welds of 9%Ni steel plates. Then, tests on mechanical properties were conducted for the welds made with this technology. The results show that the tensile, bending and low-temperature impact properties of the specimens can meet the requirements of relevant standards. In particular, the low-temperature Charpy impact energy of the heat affected area is 17.6% higher than that of SMAW. In addition, the vertical FCAW was applied to a 16×104 m3 LNG tank in a LNG receiving terminal of China, with the welding efficiency increased by 52% and the welding repair rate reduced by 2% in comparison to SMAW. In addition, the tank passed the hydrostatic test, kept stable in trial run, and was put into operation. So, the research results could provide some theoretical guidance and practical basis for the promotion of automatic welding for vertical welds of inner LNG storage tank in the future

Additional file 1: of Regional anesthesia and lipid resuscitation for local anesthetic systemic toxicity in China: results of a survey by the orthopedic anesthesia group of the chinese society of anesthesiology

Survey questionnaire. (DOC 53 kb

Light transmittance in human atrial tissue and transthoracic illumination in rats support translatability of optogenetic cardioversion of atrial fibrillation

Background: Optogenetics could offer a solution to the current lack of an ambulatory method for the rapid automated cardioversion of atrial fibrillation (AF), but key translational aspects remain to be studied. Objective: To investigate whether optogenetic cardioversion of AF is effective in the aged heart and whether sufficient light penetrates the human atrial wall. Methods: Atria of adult and aged rats were optogenetically modified to express light-gated ion channels (i.e., red-activatable channelrhodopsin), followed by AF induction and atrial illumination to determine the effectivity of optogenetic cardioversion. The irradiance level was determined by light transmittance measurements on human atrial tissue. Results: AF could be effectively terminated in the remodeled atria of aged rats (97%, n = 6). Subsequently, ex vivo experiments using human atrial auricles demonstrated that 565-nm light pulses at an intensity of 25 mW/mm2 achieved the complete penetration of the atrial wall. Applying such irradiation onto the chest of adult rats resulted in transthoracic atrial illumination as evidenced by the optogenetic cardioversion of AF (90%, n = 4). Conclusion: Transthoracic optogenetic cardioversion of AF is effective in the aged rat heart using irradiation levels compatible with human atrial transmural light penetration.Electronic Components, Technology and Material