Super-sparse marine 3D: A game changer for seismic exploration

TotalEnergies SE and partners Shell and PetroSA recently completed the acquisition and processing of a large (10,000 km2) ultra-sparse (200 m between streamers) marine seismic acquisition survey off the west coast of South Africa in block 5/6/7 using a large PGS Titan Class Ramform vessel. The sparse design enabled fast acquisition and low survey cost and health, safety, and environment exposure. Advances in sparse processing enabled high-quality final seismic data consistent with the exploration objectives. In addition, DUG optimized the 4D regularization/interpolation parameters to approach the near offsets differently than the offsets with more complete coverage to help several processing steps. The survey was designed to be upgradable to a higher-resolution survey if needed via the addition of a custom regular infill pattern, either in its entirety or over targeted areas.

New bang-bang phase detectors for high-speed serial links

Bang-bang phase detector studies were carried out in this thesis. Based on the comparison of linear and non-linear phase detectors, a hybrid phase detector was proposed. It possesses the characteristics of two-XOR phase detectors and improved bang-bang phase detectors. PLLs with the proposed hybrid phase detector possess low timing jitter in lock states and a fast locking process. The effectiveness of the proposed hybrid phase detector was quantified by comparing the performance of three PLLs with identical loop components but different phase detectors. A new bang-bang phase detector with regenerative DFFs was also proposed. The regenerative bang-bang phase detector ensures a fast acquisition of incoming clocks. The effectiveness of the regenerative phase detector was assessed in a 2GHz PLL. A 1X bang-bang phase detector was proposed also. Compared to a 2X bang-bang phase detector, PLLs with a 1X bang-bang phase detector offer faster locking. A DFF frequency detector and a charge-pump frequency detector were also proposed. Both effectively detect the frequency difference.

New bang-bang phase detectors for high-speed serial links

Bang-bang phase detector studies were carried out in this thesis. Based on the comparison of linear and non-linear phase detectors, a hybrid phase detector was proposed. It possesses the characteristics of two-XOR phase detectors and improved bang-bang phase detectors. PLLs with the proposed hybrid phase detector possess low timing jitter in lock states and a fast locking process. The effectiveness of the proposed hybrid phase detector was quantified by comparing the performance of three PLLs with identical loop components but different phase detectors. A new bang-bang phase detector with regenerative DFFs was also proposed. The regenerative bang-bang phase detector ensures a fast acquisition of incoming clocks. The effectiveness of the regenerative phase detector was assessed in a 2GHz PLL. A 1X bang-bang phase detector was proposed also. Compared to a 2X bang-bang phase detector, PLLs with a 1X bang-bang phase detector offer faster locking. A DFF frequency detector and a charge-pump frequency detector were also proposed. Both effectively detect the frequency difference.

Label-free super-resolution chemical imaging of biomedical specimens

Raman microscopy provides chemically selective imaging by exploiting intrinsic vibrational properties of specimens. Yet, a fast acquisition, low phototoxicity, and non-specific (to a vibrational/electronic mode) super-resolution method has been elusive for tissue imaging. We demonstrate a single-pixel-based approach, combined with robust structured illumination, that enables fast super-resolution in stimulated Raman scattering microscopy at low power levels. The methodology is straightforward to implement and compatible with thick biological specimens, therefore paving the way for probing complex biological systems when exogenous labelling is challenging.