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Flexible rock sheds mainly consisting of flexible nets and vaulted steel structures are a new type of device engineered to stop rockfalls. Full-scale experiments have been conducted on a flexible single-module rock shed in the last few years. Because the mechanical characteristics of a flexible three-module rock shed are much different from those of a single-module system, a flexible three-module rock shed aimed at withstanding a rockfall with kinetic energy ranging from 100 to 250 kJ is designed and built. According to the European testing standards (ETAG 027), full-scale experiments on the three-module rock shed are carried out under the impact of rock blocks with a service energy level (SEL) of 100 kJ and a maximum energy level (MEL) of 250 kJ. The flexible three-module rock shed could be put into service again and required no repair after the SEL tests, but it needed simple maintenance before returning to service after the MEL test. Furthermore, the weakness parts of the three-module rock shed, including the arch beams between the longitudinal supports and the connections between the arch beams and the stand columns, needed extra reinforcement. In addition, the cross sections of the stand columns, the diameter of the hoop support cables and the windings in the ring sets could be reduced for optimal design.

To assess diagnostic values of 2D three-section ultrasound including central sagittal section of the face, axial section of the superior alveolar process, and coronal section of the posterior triangle of the nose and 3D tomographic ultrasound imaging (TUI) in fetal cleft palate at 11–13+6weeks.

We demonstrate flexible multidimensional modulation formats, polarization multiplexed k-symbol check quadrature phase shift keying (PM-kSC-QPSK), based on PM-QPSK constellations for elastic optical networks. The experimental results show a significant optical signal noise ratio (OSNR) tolerance improvement for PM-2SC-QPSK and PM-4SC-QPSK over PM-QPSK in both back-to-back and 500 km transmission scenarios at the expense of spectral efficiency reduction. This flexible modulation method can be used in elastic optical networks to provide a trade-off between the spectral efficiency and OSNR tolerance.