Short Range Imaging Using Ultrasonic Signals

Develop hardware and software to make distance measurements using ultrasonic signals. The main goal is to use the signals to create 2D and 3D images at short ranges and in confined spaces.https://digitalcommons.mtech.edu/urp_aug_2018/1005/thumbnail.jp

Social Justice, The Common Weal and Children and Young People in Scotland

This paper argues that: • Scotland should organise itself around social justice, which addresses entitlements, redistribution, recognition and respect. • Children and young people have particular views on what social justice means for them. • Rights have a particular contribution to make to social justice in term of entitlements, claims and minimal standards. • The combination of piecemeal incorporation of children’s rights, an apolitical wellbeing framework and a lack of strong legislation to hold local authorities and other public services, private sector organisations and the third sector to account, results in children and young people encountering discrimination on an everyday basis. • To achieve social justice, a change is needed in how adults perceive children and childhood, young people and youth. Children and young people need to be recognised as contributors to their families, institutions and communities now – and not just in the future. • For children and young people to be included in the Common Weal, it needs to be concerned with the full and diverse range of structural, cultural and individual barriers that they encounter in their lives

Design and fabrication of highly efficient non-linear optical devices for implementing high-speed optical processing

We present the design and fabrication of micro-cavity semiconductor devices for enhanced Two-Photon-Absorption response, and demonstrate the use of these devices for implementing sensitive autocorrelation measurements on pico-second optical pulses

High-sensitivity two-photon absorption microcavity autocorrelator

A GaAs-AlAs microcavity device has been used as a photodetector in an autocorrelator for measuring the temporal pulsewidth of 1.5-/spl mu/m optical pulses. Enhancement of the two-photon absorption photocurrent due to the microcavity structure results in an autocorrelation (average power times peak power) sensitivity of 9.3/spl times/10/sup -4/ (mW)/sup 2/, which represents two orders of magnitude improvement when compared with conventional autocorrelators

Two-photon absorption in microcavities for optical autocorrelation and sampling

We have designed novel semiconductor microcavity structures for the enhancement of the two-photon absorption (TPA) photocurrent. We report a TPA autocorrelation technique for short optical pulses that uses the microcavity structure instead of a second harmonic generation crystal. Knowledge of these characteristics is important for implementation in applications such as optical switching and sampling in optical time division multiplexed (OTDM) communications systems

A novel approach towards two-photon absorption based detectors

Summary: We have demonstrated that the inherent inefficiency of the TPA process in semiconductors can be overcome by incorporating the semiconductor in a microcavity structure. Proof of concept devices with a 0.27μm Ga0.7Al0.3As active region and two Bragg reflectors with the cavity resonance of 890 nm were fabricated. We measured the TPA photocurrent of these devices and have demonstrated a factor of 12000 enhancement over a nonmicrocavity device at 890 nm. Our active length of 0.27 nm is as efficient as 5.4 mm without a microcavity, overcoming the very long detector lengths limiting the use of TPA in practical autocorrelators, optical switches and sampling devices for real telecommunication systems. The effect of the cavity is to enhance the intra-cavity optical intensity, which leads to an increase in the nonlinear response of the active region. We studied, theoretically and experimentally, the impact of the cavity on the temporal response and the sensitivity of the device, which are critical considerations for commercial applications. This cavity design has a 3 pico-second response time and the autocorrelation trace is comparable with the BBO crystal response for an input 1.6 ps pulse. Devices designed for 1550 nm have also been realised and our measurements indicate these two-photon absorption based detectors are potential candidates for optical autocorrelation of short optical pulses, and for optical switching and sampling in optical time division multiplexed (OTDM) communications systems

Heterobimetallic μ2-carbido complexes of platinum and tungsten

The tungsten-platinum μ-carbido complex [WPt(μ-C)Br(CO)2(PPh3)2(Tp*)] (Tp* = hydrotris(dimethylpyrazol-1-yl)borate) undergoes facile substitution of both bromide and phosphine ligands to afford a diverse library of μ-carbido complexes that includes [WPt(μ-C)Br(CO)2(dppe)(Tp*)], [WPt(μ-C)(NCMe)(CO)2(PPh3)2(Tp*)]OTf, [WPt(μ-C)(S2CNEt2)(CO)2(PPh3)(Tp*)], [WPt(μ-C)(bipy)(CO)2(PPh3)(Tp*)]PF6, [WPt(μ-C)(phen)(CO)2(PPh3)(Tp*)]PF6, [WPt(μ-C)(terpy)(CO)2(Tp*)]PF6, [WPt(μ-C)(CO)2(PPh3)(Bp*)(Tp*)], [WPt(μ-C)(CO)2(PPh3)(Tp*)2] and [WPt(μ-C)(bipy)(CO)2(PPh3)(Bm)(Tp*)], most of which have been structurally charcaterised.DP170102695 and DP19010072

Evaluation of a Multi-Sensor Platform in a Large-Scale Geophysical Survey at Brú na Bóinne World Heritage Site, Ireland

This poster presents comparative results from the first use of the Geophysical Exploration Equipment Platform (GEEP) in Ireland in carrying out a multi-sensor survey in the vicinity of a possible Neolithic passage tomb known as Site E in the Brú na Bóinne World Heritage Site. Brú na Bóinne, a UNESCO World Heritage Site, has been an important ritual, social and economic centre for thousands of years. Much research has been undertaken in the area, including large-scale excavations at the Neolithic passage tombs of Newgrange and Knowth. However we still lack an in-depth understanding of the site’s broad range of archaeological monuments, and the landscape and communities that shaped them. To date there has been no systematic large-scale use of ground geophysical techniques although a number of successful spatially discrete geophysical surveys have been carried out. The landscape has many large, open fields under pasture or tillage suitable for systematic large-scale ground geophysical survey. Such a survey, integrated with the interpretation of other available remote sensing data is an obvious next step in the investigation of this internationally important landscape. The evaluation was successful and the results from the GEEP dataset will be presented with a comparative study of data collected by traditional hand-carried magnetic gradiometry, earth resistance and magnetic susceptibility surveys

Construction of an iminoketenylidene

The new isonitrile-mu-carbido complexes [WPt(mu-C)Br(CNR)(PPh3)(CO)(2)(Tp*)] (R = C6H2Me3-2,4,6, C6H3Me2-2,6; Tp* = hydrotris(dimethylpyrazolyl)borate) rearrange irreversibly in polar solvents to provide the first examples of iminoketenylidene (CCNR) complexes.We gratefully acknowledge the Australian Research Council (DP190100723 and DP200101222) for funding. We gratefully acknowledge the assistance of Dr M. G. Gardiner with crystallographic analyses