Study the Nonlinearity in Sonic IR Imaging NDE

Sonic IR Imaging combines pulsed ultrasound excitation and infrared imaging to detect defects in materials. The sound pulse causes rubbing due to non-‐unison motion between faces of defects, and infrared sensors image the temperature map over the target to identify defects. It works in various materials, including metal/metal alloy, ceramics, and composite materials. Its biggest advantage is that it\u27s a fast, wide area NDE technique. It takes only a fraction of a second or a few seconds, depending on the thermal properties of the target, for one test over a few square feet. However, due to the nonlinearity in the coupling between the ultrasound transducer and the target, the repeatability has been an issue, which affects its application. In this paper, we will present our study on this issue in Sonic IR

Phosphate/Pyrophosphate and MV-related Proteins in Mineralisation: Discoveries from Mouse Models

During the process of matrix vesicle (MV)-mediated initiation of mineralisation, chondrocytes and osteoblasts mineralise the extracellular matrix by promoting the seeding of basic calcium phosphate crystals of hydroxyapatite (HA) along the collagen fibrils. This orchestrated process is carefully regulated by the balanced action of propagators and inhibitors of calcification. The primary antagonistic regulators of extracellular matrix mineralisation are phosphate (Pi) and inorganic pyrophosphate (PPi). Studies in mouse models and in humans have established critical roles for Pi/PPi homeostasis in biomineralisation. In this review, we present the regulators of Pi/PPi, as derived from animal models, and discuss their clinical relevance to physiological and pathological mineralisation

Transformation of Chinese as a Foreign Language Teachers’ Relationship with Their Students in the Australian Context

This study explores the transformation of teacher–student relationship between expatriate Chinese as a Foreign Language (CFL) teachers and their students situating in the Australian educational context. The disparity of tradition between the two educational cultures influences substantially on communication between teachers and students within classroom. To better understand how CFL teachers’ background educational culture may impact their interaction with Australian students, focus group discussion data were applied as the data collection method. Findings reveal that at the beginning of their teaching practice CFL teachers’ understanding of teacher–student relationship influenced by their background educational culture had major impact on their strategies in teacher–student interaction in class. However, with the progress of teaching and meantime influenced by the Australian local educational culture, their behaviors for dealing with teacher–student relationship in class changed. Basically, their ways of handling teacher–student relationship transformed from a more Eastern guanxi tendency to a more Western rapport tendency. This transformation did not occur automatically and easily; it was achieved by the CFL teachers’ struggles and tribulations in the process of interacting with their Australian students. In an era of CFL teacher shortage, it is hoped that this study would shed some light on CFL teacher education

STAR-RIS Assisted Covert Communications in NOMA Systems

Covert communications assisted by simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) in non-orthogonal multiple access (NOMA) systems have been explored in this paper. In particular, the access point (AP) transmitter adopts NOMA to serve a downlink covert user and a public user. The minimum detection error probability (DEP) at the warden is derived considering the uncertainty of its background noise, which is used as a covertness constraint. We aim at maximizing the covert rate of the system by jointly optimizing APs transmit power and passive beamforming of STAR-RIS, under the covertness and quality of service (QoS) constraints. An iterative algorithm is proposed to effectively solve the non-convex optimization problem. Simulation results show that the proposed scheme significantly outperforms the conventional RIS-based scheme in ensuring system covert performance.Comment: arXiv admin note: text overlap with arXiv:2305.04930, arXiv:2305.0399