Fluorescent nanodiamonds (FNDs) have drawn much attention in recent years for biomedical imaging applications due to their desired physical properties including excellent photostability, high biocompatibility, extended far-red fluorescence emission, and ease of surface functionalization. Here we explore a new feature of FNDs, i.e. their photoacoustic emission capability, which may lead to potential applications of using FNDs as a dual imaging contrast agent for combined fluorescence and photoacoustic imaging modalities. We observed significant enhancement of photoacoustic emission from FNDs when they were conjugated with gold nanoparticles (GNPs).

Fluorescent nanodiamonds (FNDs) with a size in the range of 10 – 100 nm have been produced by ion irradiation and annealing, and isolated by differential centrifugation. Single particle spectroscopic characterization with confocal fluorescence microscopy and fluorescence correlation spectroscopy indicates that they are photostable and useful as an alternative to far-red fluorescent proteins for bioimaging applications. We demonstrate the application by performing in vivo imaging of bare and bioconjugated FND particles (100 nm in diameter) in C. elegans and zebrafishes and exploring the interactions between this novel nanomaterial and the model organisms. Our results indicate that FNDs can be delivered to the embryos of both organisms by microinjection and eventually into the hatched larvae in the next generation. No deleterious effects have been observed for the carbon-based nanoparticles in vivo. The high fluorescence brightness, excellent photostability, and nontoxic nature of the nanomaterial have allowed long-term imaging and tracking of embryogenesis in the organisms.

Offshore wind farms have a superior wind source to terrestrial wind farms, but they also face more severe environmental conditions such as severe storms, typhoons, and sea waves. Scour leads to the excavation of sediments around the foundations of structures, reducing the safe capacity of the structures. The phenomenon of pier scour is extremely complex because of the combined effects of the vortex system involving time-dependent flow patterns and sediment transport mechanisms. A real-time scour monitoring system can improve the safety of structures and afford cost-effective operations by preventing premature or unnecessary maintenance. This paper proposes an on-site scour monitoring system using visible light communication (VLC) modules for offshore wind turbine installations. A flume experiment revealed that the system was highly sensitive and accurate in monitoring seabed scour processes. This arrayed-VLC sensory system, proposed in this paper, has considerable potential for safety monitoring and also can contribute to improving the accuracy of empirical scour formulas for sustainable maintenance in the life cycle of offshore structures.

Abstract. In this paper, we give some characterizations of matrices which have defect index one. Recall that an n -by-n matrix A is said to be of class S n (resp., S −1 n ) if its eigenvalues are all in the open unit disc (resp., in the complement of closed unit disc) and rank (I n − A * A) = 1 . We show that an n -by-n matrix A is of defect index one if and only if A is unitarily equivalent to U ⊕ C , where U is a k -by-k unitary matrix, 0 k < n , and C is either of class S n−k or of class S −1 n−k . We also give a complete characterization of polar decompositions, norms and defect indices of powers of S −1 n -matrices. Finally, we consider the numerical ranges of S −1 n -matrices and S n -matrices, and give a generalization of a result of Chien and Nakazato on tridiagonal matrices (cf. [3, Theorem 7]). Mathematics subject classification (2010): 47A12, 15A60.