5 research outputs found
Ultra-thin friction stir welding on Aluminum alloy
No full textUltra-thin sheets' welding is an intricate process either by conventional or advanced techniques. In the present investigation, Micro friction stir welding (FSW) was successfully performed to join the ultra-thin (0.5 mm thick) commercial aluminum. Suitable fixture and tool were developed for the ultra-thin sheets to perform experiments. Velocity ratio of rotational speed to transvers speed was varied to obtain ultra-thin friction stir welding. The welded samples were investigated by visual examination, macro-graphs, microstructure, tensile testing with fracture surface analysis and micro hardness distribution. The results revealed that, the sound joint was achieved at the velocity ratio of 13.71. The tensile strength of 100.877 N/mm2 and elongation of 23.12% were obtained, which were 90.77% and 51.377% of the parent material respectively. Fracture surfaces after tensile testing was observed with elongated dimples indicating ductile fracture. The maximum micro hardness of 94 HV was observed in the weld zone
Dynamic modeling of the heat pipe-assisted annealing line
No full textIn a conventional continuous annealing line, the energy supplied to steel strip during heating is not recovered while cooling it. Therefore, an alternative heat transfer technology for energy efficient continuous annealing of steel was developed. This technology enables reusing the heat extracted during cooling of the strip in the heating part of the process. This is achieved by thermally linking the cooling strip to the heating strip via multiple rotating heat pipes. In this context, the dynamic simulation of a full heat pipe assisted annealing line is performed. The dynamic simulation consists of the interaction of computational building blocks, each comprising of a rotating heat pipe and strip parts wrapped around the heat pipe. The simulations are run for different installation configurations and operational settings, with the heat pipe number varying between 50 and 100 and with varying strip line speed and dimensions. The heat pipes are sized to be 0.5 m in diameter and 3 m in length. The simulation results show that the equipment is capable of satisfying the thermal cycle requirements of annealing both at steady-state and during transition between steady-states following changes in boundary conditions. With this concept, energy savings of up to 70% are feasible.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Large Scale Energy StorageProcess and EnergyEnergy Technolog
Ultra-thin friction stir welding on Aluminum alloy
No full textUltra-thin sheets’ welding is an intricate process either by conventional or advanced techniques. In the present investigation, Micro friction stir welding (FSW) was successfully performed to join the ultrathin (0.5 mm thick) commercial aluminum. Suitable fixture and tool were developed for the ultra-thin sheets to perform experiments. Velocity ratio of rotational speed to transvers speed was varied to obtain ultra-thin friction stir welding. The welded samples were investigated by visual examination, macrographs, microstructure, tensile testing with fracture surface analysis and micro hardness distribution. The results revealed that, the sound joint was achieved at the velocity ratio of 13.71. The tensile strength of 100.877 N/mm2 and elongation of 23.12% were obtained, which were 90.77% and 51.377% of the parent material respectively. Fracture surfaces after tensile testing was observed with elongated dimples indicating ductile fracture. The maximum micro hardness of 94 HV was observed in the weld zone.Peer reviewe
Author Correction: Partial inhibition of mitochondrial complex I ameliorates Alzheimer’s disease pathology and cognition in APP/PS1 female mice
No full textGlobal treatment of haemorrhoids—A worldwide snapshot audit conducted by the International Society of University Colon and Rectal Surgeons
No full textAim: There is no universally accepted treatment consensus for haemorrhoids, and thus, management has been individualized all over the world. This study was conducted to assess a global view of how surgeons manage haemorrhoids. Methods: The research panel of the International Society of University Colon and Rectal Surgeons (ISUCRS) developed a voluntary, anonymous questionnaire evaluating surgeons' experience, volume and treatment approaches to haemorrhoids. The 44 multiple-choice questionnaire was available for one month via the ISUCRS email database and the social media platforms Viber and WhatsApp. Results: The survey was completed by 1005 surgeons from 103 countries; 931 (92.6%) were in active practice, 819 (81.5%) were between 30 and 60 years of age, and 822 (81.8%) were male. Detailed patient history (92.9%), perineal inspection (91.2%), and digital rectal examination (91.1%) were the most common assessment methods. For internal haemorrhoids, 924 (91.9%) of participants graded them I–IV, with the degree of haemorrhoids being the most important factor considered to determine the treatment approach (76.3%). The most common nonprocedural/conservative treatment consisted of increased daily fibre intake (86.9%), increased water intake (82.7%), and normalization of bowel habits/toilet training (74.4%). Conservative treatment was the first-line treatment for symptomatic first (92.5%), second (72.4%) and third (47.3%) degree haemorrhoids; however, surgery was the first-line treatment for symptomatic fourth degree haemorrhoids (77.6%). Rubber band ligation was the second-line treatment in first (50.7%) and second (47.2%) degree haemorrhoids, whereas surgery was the second-line treatment in third (82.9%) and fourth (16.7%) degree symptomatic haemorrhoids. Rubber band ligation was performed in the office by 645(64.2%) of the participants. The most common surgical procedure performed for haemorrhoids was an excisional haemorrhoidectomy for both internal (87.1%) and external (89.7%) haemorrhoids – with 716 (71.2%) of participants removing 1, 2 or 3 sectors as necessary. Conclusion: Although there is no global haemorrhoidal treatment consensus, there are many practice similarities among the different cultures, resources, volume and experience of surgeons around the world. With additional studies, a consensus statement could potentially be developed
