Growth of Al<SUB>2</SUB>O<SUB>3</SUB>/Al composites from Al-Zn alloys

Observations are presented here of the initiation and growth of an Al2O3composite by the directed oxidation of a molten binary Al-Zn alloy with and without preforms. The oxidation behaviour into free space begins with the formation of ZnO on the melt surface followed by a second stage of relatively high growth rate associated with the constant presence of ZnO and a final region of slow growth rate during which the surface consists of both ZnO as well as Al2O3. Composite formation is explained on the basis of a cyclic formation and reduction by molten aluminium of ZnO. Oxidation was carried out with ternary Mg additions into Al2O3 preforms of different particle sizes. The infiltration of an Al2O3 preform is governed by reaction induced wetting between alloy and ZnO. Nucleation of the alumina is epitaxial with respect to particles of the preform and growth rates are higher than that for composite growth into free space

Reversal and pinning of Curie point transformations in thin film piezoelectrics

The Curie point for a rhombohedral piezoelectric thin film was established by in situ micro-Raman spectroscopy. The hysteresis in phase reversal and specific thermal conditions for disrupting such reversal were determined

Some observations on light fishing off Thiruvananthapuram coast

The artisanal fisheries of the Thiruvananthapuram coast axe of considerable importance in the fisheries of Kerala State due to their significant contributions to the catch of resources like tunas, anchovies, ribbonfish, caranglds, perches and cephalopods

The Stardust – a successful encounter with the remarkable comet Wild 2

On January 2, 2004 the Stardust spacecraft completed a close flyby of comet Wild2 (P81). Flying at a relative speed of 6.1 km/s within 237km of the 5 km nucleus, the spacecraft took 72 close-in images, measured the flux of impacting particles and did TOF mass spectrometry

Investigations in the rôle of organic matter in plant nutrition. Part IV. Chemical and biological transformations attendant on the application of cane molasses to swamp soil

This article does not have an abstract

Non-thermal transport of energy driven by photoexcited carriers in switchable solid states of GeTe

Phase change alloys have seen widespread use from rewritable optical discs to the present day interest in their use in emerging neuromorphic computing architectures. In spite of this enormous commercial interest, the physics of carriers in these materials is still not fully understood. Here, we describe the time and space dependence of the coupling between photoexcited carriers and the lattice in both the amorphous and crystalline states of one phase change material, GeTe. We study this using a time-resolved optical technique called picosecond acoustic method to investigate the \textit{in situ} thermally assisted amorphous to crystalline phase transformation in GeTe. Our work reveals a clear evolution of the electron-phonon coupling during the phase transformation as the spectra of photoexcited acoustic phonons in the amorphous ($a$-GeTe) and crystalline ($\alpha$-GeTe) phases are different. In particular and surprisingly, our analysis of the photoinduced acoustic pulse duration in crystalline GeTe suggests that a part of the energy deposited during the photoexcitation process takes place over a distance that clearly exceeds that defined by the pump light skin depth. In the opposite, the lattice photoexcitation process remains localized within that skin depth in the amorphous state. We then demonstrate that this is due to supersonic diffusion of photoexcited electron-hole plasma in the crystalline state. Consequently these findings prove the existence of a non-thermal transport of energy which is much faster than lattice heat diffusion

Plasmon resonances of highly doped two-dimensional MoS2

The exhibition of plasmon resonances in two-dimensional (2D) semiconductor compounds is desirable for many applications. Here, by electrochemically intercalating lithium into 2D molybdenum disulfide (MoS2) nanoflakes, plasmon resonances in the visible and near UV wavelength ranges are achieved. These plasmon resonances are controlled by the high doping level of the nanoflakes after the intercalation, producing two distinct resonance peak areas based on the crystal arrangements. The system is also benchmarked for biosensing using bovine serum albumin. This work provides a foundation for developing future 2D MoS2 based biological and optical units

Working together better for mental health in children and young people during a pandemic: experiences from North Central London during the first wave of COVID-19

Direct risk from infection from COVID-19 for children and young people (CYP) is low, but impact on services, education and mental health (so-called collateral damage) appears to have been more significant. In North Central London (NCL) during the first wave of the pandemic, in response to the needs and demands for adults with COVID-19, general paediatric wards in acute hospitals and some paediatric emergency departments were closed. Paediatric mental health services in NCL mental health services were reconfigured. Here we describe process and lessons learnt from a collaboration between physical and mental health services to provide care for CYP presenting in mental health crisis. Two new ‘hubs’ were created to coordinate crisis presentations in the region and to link community mental health teams with emergency departments. All CYP requiring a paediatric admission in the first wave were diverted to Great Ormond Street Hospital, a specialist children’s hospital in NCL, and a new ward for CYP mental health crisis admissions was created. This brought together a multidisciplinary team of mental health and physical health professionals. The most common reason for admission to the ward was following a suicide attempt (n=17, 43%). Patients were of higher acute mental health complexity than usually admitted to the hospital, with some CYP needing an extended period of assessment. In this review, we describe the challenges and key lessons learnt for the development of this new ward setting that involved such factors as leadership, training and also new governance processes. We also report some personal perspectives from the professionals involved. Our review provides perspective and experience that can inform how CYP with mental health admissions can be managed in paediatric medical settings