At present, flux or metal cored wires are widely used in iron-based materials for flux cored arc welding in order to reduce the cost of welding production. However, the development of flux or metal cored wire for titanium materials, which are widely used in the petrochemical, power plant and marine vessel fields, has not been done yet, and development is required. In this study, manufacturing process of titanium alloys flux-metal cored wire for gas tungsten arc welding was investigated by FEM simulation and experimental analysis. FEM simulation of tube welding process was carried out with initial three preform-types (butt tube, overlap tube and welded tube). In the FEM simulation results, tube welding process using initial welded tube was evaluated to cause cracking of the specimen during the process. In actual making process of titanium alloys flux-metal cored wire for gas tungsten arc welding, overlap-type tube was evaluated to be the most suitable initial preform shape. In addition, it was confirmed that the filling ratio of the flux-metal was maintained uniformly at over 70%.

The annealing condition dependence on the weldability of Ti-6Al-4V ELI alloy was studied by means of the tensile test, hardness and microstructure analysis. The Ti-6Al-4V ELI plate with 1 mm plates were joined by the fiber laser welding under 2 kw laser power and 100 mm/s welding speed condition. Various PWHT (Postweld heat treatment) conditions were used to improve the formability of the welded titanium alloy. The results showed the solution treatment for the PWHT contributes on the homogeneous strength distribution from fusion zone to base material. This PWHT conditions were expected to minimize the degradation of the formability caused by the welding.

Because of the COVID-19 pandemic, wastewater-based surveillance has garnered extensive attention in many countries, including the United States and those in Europe, by pre-emptively monitoring and responding to infectious diseases in the community. Additionally, it is actively used in national infectious disease monitoring policies. From 2021, the Korea Disease Control and Prevention Agency conducted a pilot project to prove the effectiveness of wastewater-based surveillance system in the Republic of Korea and laid the foundation to introduce a national wastewater-based surveillance system. In 2023, KOrea WAstewater Surveillance (KOWAS) project is being conducted in cooperation with 17 cities or provinces and 18 Institute of Health and Environment Researches. Henceforth, we will expand the scope of monitoring infectious diseases by cooperating with related ministries and prepare the crisis response for a potential pandemic by upgrading experimental techniques.

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Purpose The balloon-stent technique (BST) has certain strengths as an assisted technique for the treatment of complex aneurysms. After Atlas release, the BST can be executed without an exchange maneuver of the balloon to the stent-delivery catheter. The purpose of this article is to share our experience with the BST using the Scepter-Atlas combination. Materials and Methods Device inspection led us to a simple method to avoid failure in loading Atlas to the Scepter. From March 2018 to December 2019, 57 unruptured distal internal carotid artery (dICA) aneurysms were treated with coil embolization; among which, 25 aneurysms in 23 patients were treated with BST. Clinical and angiographic data were retrospectively collected and reviewed. Results The technical success rate of the Scepter-Atlas combination increased from 50% to 100% after careful inspection. BST angiographic results were comparable to the stent-assisted coil (SAC) group treated during the immediately post-embolization same period (modified Raymond-Roy classification [MRRC] 1 & 2 84% in BST, 96.3% in SAC) and during short-term follow-up (MRRC 1 & 2 95.8% in BST, 88.4% in SAC). A small number of patients showed periprocedural complications, but none had clinical consequences. Conclusion BST using the Scepter-Atlas combination can provide an effective and safe method for the treatment of dICA aneurysms. Scepters can be used as delivery catheters for Atlas.