• Journal of Power System Engineering
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• v.20 no.6
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• pp.40-45
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• 2016

The manufacturing process of large scaled Al 7050 alloy is difficult for the occurrence of solidification crack during casting. The aims of this study are the evaluations of microstructure and mechanical properties of extruded Al 7050 billet and ring forged one with large scale. Large scaled Al 7050 billet was casted by direct-chill casting process. The extruded and ring forged specimens were prepared from the casted ingot after residual stress relief and homogenization heat treatment, respectively. Microstructures, hardness and tensile test of the surface, middle and center part of each specimen were performed at room temperature. Sheared and elongated type grains were observed at the edge parts of surface and center area and its aspect ratios of grains were low and similar as 0.21 while that of middle area was closed to 0.92 value in ring forged Al 7050 alloy. The mechanical properties of extruded Al 7050 alloy were superior than those of ring forged one. The hardness values of surface and center part were slightly higher than that of middle part in ring forged Al 7050 alloy.

• Journal of Korean Foot and Ankle Society
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• v.26 no.2
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• pp.84-87
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• 2022

Purpose: This was a pilot study to examine the clinical usefulness of the newly developed three-dimensional sweep mode extracorporeal shockwave treatment (ESWT) in patients with plantar fasciitis. Materials and Methods: Three-dimensional sweep mode ESWT was performed once a week for 5 weeks in patients with plantar fasciitis who showed no improvement with the conventional conservative treatment. A 100-mm visual analogue scale (VAS) reading for pain from walking and at rest after walking were collected before the treatment and 8 and 16 weeks after the initial treatment. In addition, the Foot and Ankle Outcome Score (FAOS) and EuroQol-5-dimension (EQ-5D) scores before and 16 weeks after the treatment were evaluated. Results: VAS for pain for walking improved from 50.60±8.38 to 19.80±15.61 at 8 weeks after the initial treatment (p=0.008) and 9.80±9.62 at 16 weeks after the treatment (p<0.001). VAS for pain at rest after walking improved from 36.60±19.55 to 11.80±12.95 at 8 weeks after the initial treatment (p=0.052) and 8.80±8.87 at 16 weeks after the treatment (p=0.024). Preoperative FAOS increased from an average of 74.80±9.73 before the treatment to an average of 81.00±8.86 at week 16 after the procedure (p=0.49) and compared to pre-treatment levels, there was a decrease of one level in the anxiety/depression domain of the EQ-5D, post-treatment. Conclusion: The results of this preliminary study confirmed that the newly developed EWST with the smart forging sweep mode was effective in improving pain and function in plantar fasciitis.