Time scale difference has been compared at nanosecond level so far by using two-way satellite time and frequency transfer (TWSTFT), benefiting from many signal delays are pretty canceled out due to ...the reciprocity of propagation path. For next-generation TWSTFT which compares time scale difference at sub-nanosecond level, further studies for signal delays are necessary. This work studies the impact of the ionospheric delay corrections on next-generation TWSTFT. The results demonstrate that the ionospheric corrections vary with both latitude and solar activity. At low latitudes and during moderate or high solar activity, they can reach 200 picoseconds, and thus can affect the time precision of sub-nanosecond next-generation TWSTFT.
Treatment for bone deformities secondary to malunited fractures usually require corrective osteotomies, and high incidence of surgical failure rates have been reported. Inaccurate corrections and ...loss of reductions are among the most common causes, and these technical errors ought to be improved. A new measuring fixator for humeral supracondylar corrective osteotomies in children was designed and used in clinical application. Two boys who had sustained cubitus varus following malunited humeral supracondylar fracture were performed using proposed measuring fixator. The results of the clinical trial show that the angle of correction was accurate, and the procedure could be carried out by the surgeon himself without additional help, with an average of 1.3 penetration of the physis per each fixating Kirschner wire (8 times in 6 K-wires). The surgical time was reduced, as well as the radiation exposure.
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