Transmission system isolates pressure transducer from severe environment

Pressure transmission system measures the pressure of a high temperature, chemically active fluid by isolating the pressure transducer from the process fluid without component disconnections

Slip dislocation and twin nucleation mechanisms in hcp metals

The final publication is available at Springer via http://dx.doi.org/10.1007/s10853-016-0351-4A new nucleation mechanism is proposed for {101¯1} deformation twin in hcp materials. The mechanism is based on the results of atomistic computer simulations. It was found that under high shear stress applied on {101¯1} plane (the stress level is about 7 % of shear modulus), the core of a slip dislocation can transform to a twin embryo. The transformation and subsequent twin growth are accompanied by nucleation and migration of interfacial defects including disconnections and stacking faults. The paper provides the analysis of the nature of these defects and describes the reactions between them.Peer ReviewedPostprint (author's final draft

Atomic displacements accompanying deformation twinning: shears and shuffles

Deformation twins grow by the motion of disconnections along their interfaces, thereby coupling shear with migration. Atomic-scale simulations of this mechanism have advanced to the point where the trajectory of each atom can be followed as it transits from a site in the shrinking grain, through the interface, and onwards to a site in the growing twin. Historically, such trajectories have been factorised into shear and shuffle components according to some defined convention. In the present article, we introduce a method of factorisation consistent with disconnection motion. This procedure is illustrated for the case of {10-12} twinning in hcp materials, and shown to agree with simulated atomic trajectories for Zr.Peer ReviewedPostprint (published version

On the relationship between {1 1 2¯ 2} and {1 1 2¯ 6} conjugate twins and double extension twins in rolled pure Mg

This is an Accepted Manuscript of an article published by Taylor & Francis Group in Philosophical Magazine on February 2017, available online at: http://www.tandfonline.com/10.1080/14786435.2017.1290846The paper presents a new type of twin-like objects observed in rolled pure magnesium. They have {11¯26} and {11¯22} habit planes and their misorientations to the matrix are close to 56° and 63° about ¿10¯10¿ axis, respectively. The ad hoc performed theoretical analysis and atomic simulations allow to interpret the objects as {10¯12}-{10¯12} double twins formed by the simultaneous action of two twinning shears with completely re-twinned volume of primary twin. The observed inclinations from the ideal misorientations for such double twins can be explained by the compliance of the strain invariant condition in the twin boundary. It seems plausible that, once the double twin is formed, its twin boundaries are hard to move by glide of twinning disconnections. If so, these twins represent obstacles for the motion of crystal dislocations increasing the hardness of the metal.Peer ReviewedPostprint (author's final draft

Evaluating Resilience of Electricity Distribution Networks via A Modification of Generalized Benders Decomposition Method

This paper presents a computational approach to evaluate the resilience of electricity Distribution Networks (DNs) to cyber-physical failures. In our model, we consider an attacker who targets multiple DN components to maximize the loss of the DN operator. We consider two types of operator response: (i) Coordinated emergency response; (ii) Uncoordinated autonomous disconnects, which may lead to cascading failures. To evaluate resilience under response (i), we solve a Bilevel Mixed-Integer Second-Order Cone Program which is computationally challenging due to mixed-integer variables in the inner problem and non-convex constraints. Our solution approach is based on the Generalized Benders Decomposition method, which achieves a reasonable tradeoff between computational time and solution accuracy. Our approach involves modifying the Benders cut based on structural insights on power flow over radial DNs. We evaluate DN resilience under response (ii) by sequentially computing autonomous component disconnects due to operating bound violations resulting from the initial attack and the potential cascading failures. Our approach helps estimate the gain in resilience under response (i), relative to (ii)

Network-analysis-guided synthesis of weisaconitine D and liljestrandinine.

General strategies for the chemical synthesis of organic compounds, especially of architecturally complex natural products, are not easily identified. Here we present a method to establish a strategy for such syntheses, which uses network analysis. This approach has led to the identification of a versatile synthetic intermediate that facilitated syntheses of the diterpenoid alkaloids weisaconitine D and liljestrandinine, and the core of gomandonine. We also developed a web-based graphing program that allows network analysis to be easily performed on molecules with complex frameworks. The diterpenoid alkaloids comprise some of the most architecturally complex and functional-group-dense secondary metabolites isolated. Consequently, they present a substantial challenge for chemical synthesis. The synthesis approach described here is a notable departure from other single-target-focused strategies adopted for the syntheses of related structures. Specifically, it affords not only the targeted natural products, but also intermediates and derivatives in the three families of diterpenoid alkaloids (C-18, C-19 and C-20), and so provides a unified synthetic strategy for these natural products. This work validates the utility of network analysis as a starting point for identifying strategies for the syntheses of architecturally complex secondary metabolites

Disconnections case studies: understanding the householder experience

A dramatic increase in the number of Victorian households experiencing involuntary electricity and/or gas disconnections has prompted a review of disconnections by the Victorian government. This research into the direct and indirect costs that arise from disconnections was commissioned by the Consumer Action Law Centre and contributed to their \u27Heat or Eat\u27 report. Summary of key themes 1) Disconnections were part of complex family, health and financial circumstances. Disconnections did not occur in a vacuum: participants were typically experiencing numerous financial stresses at the time when they were disconnected, and these were often intertwined with complex crises. Domestic violence was often a contributing factor. 2) Inadequate retailer responses and practices. Participants\u27 reports indicated numerous deficiencies in retailer practices including demands for unreasonable upfront and ongoing payments, lack of information about services and concessions which could assist householders, and aggressive marketing practices.  3) Impact on mental health and wellbeing. Disconnections caused significant distress for most participants. Participants experienced feelings of shame, humiliation, fear and anxiety. The disconnection events compounded existing mental health issues and had a serious impact on participants’ wellbeing. 4) Financial impact. Disconnections resulted in various extra costs for participants that made it harder to get out of debt and avoid future payment defaults and disconnections. In addition to disconnection and reconnection fees, less obvious costs included: replacement of spoilt food; take-away meals for the family; use of public laundries or BBQs; phone calls; entry to public facilities to shower; and purchase of candles, blankets and other goods to manage in the absence of heating, lighting etc. 5) Impact on dependants. The disconnections often impacted children. Parents struggled to provide food and worried about the health and emotional impact on their children. 6) Financial counsellors and the Energy and Water Ombudsman Victoria. Financial counsellors and/or EWOV eventually assisted negotiations for participants and usually achieved outcomes that participants had not been able to. However, it took time to find this assistance because participants were unaware of these services or where to look for them