A selected ion flow tube study of the reactions of gas-phase cations with PSCl3

A selected ion flow tube was used to investigate the positive ion chemistry of thiophosphoryl chloride, PSCl$_3$. Rate coefficients and ion product branching ratios have been determined at room temperature for reactions with nineteen cations ; H$_3$O$^+$, CF$_3^+$, CF$^+$, NO$^+$, NO$_2^+$, SF$_2^+$, SF$^+$, CF$_2^+$, O$_2^+$, H$_2$O$^+$, N$_2$O$^+$, O$^+$, CO$_2^+$, CO$^+$, N$^+$, N$_2^+$, Ar$^+$, F$^+$ and Ne$^+$ (in order of increasing recombination energy). Complementary data described in the previous paper have been obtained for this molecule via the observation of threshold photoelectron photoion coincidences. For ions whose recombination energies are in the range 10-22 eV, comparisons are made between the product ion branching rations of PSCl$_3$ from photoionisation and from ion-molecule reactions. In most instances, the data from the two experiments are well correlated, suggesting that long-range charge transfer is the dominant mechanism for these ion-molecule reactions ; the agreement is particularly good for the atomic ions Ar$^+$, F$^+$ and Ne$^+$. Some reactions (e.g. O$_2^+$ + PSCl$_3$), however, exhibit significant differences; short-range charge transfer must then be occurring following the formation of an ion-molecule complex. For ions whose recombination energies are less than 10 eV (i.e. H$_3$O$^+$, CF$_3^+$, CF$^+$ and NO$^+$), reactions can only occur via a chemical process in which bonds are broken and formed, because the recombination energy of the cation is less than the ionisation energy of PSCl$_3$

Experimental considerations of acute heat stress assays to quantify coral thermal tolerance

Understanding the distribution and abundance of heat tolerant corals across seascapes is imperative for predicting responses to climate change and to support novel management actions. Thermal tolerance is variable in corals and intrinsic and extrinsic drivers of tolerance are not well understood. Traditional experimental evaluations of coral heat and bleaching tolerance typically involve ramp-and-hold experiments run across days to weeks within aquarium facilities with limits to colony replication. Field-based acute heat stress assays have emerged as an alternative experimental approach to rapidly quantify heat tolerance in many samples yet the role of key methodological considerations on the stress response measured remains unresolved. Here, we quantify the effects of coral fragment size, sampling time point, and physiological measures on the acute heat stress response in adult corals. The effect of fragment size differed between species (Acropora tenuis and Pocillopora damicornis). Most physiological parameters measured here declined over time (tissue colour, chlorophyll-a and protein content) from the onset of heating, with the exception of maximum photosynthetic efficiency (Fv/Fm) which was surprisingly stable over this time scale. Based on our experiments, we identified photosynthetic efficiency, tissue colour change, and host-specific assays such as catalase activity as key physiological measures for rapid quantification of thermal tolerance. We recommend that future applications of acute heat stress assays include larger fragments (> 9 cm2) where possible and sample between 10 and 24 h after the end of heat stress. A validated high-throughput experimental approach combined with cost-effective genomic and physiological measurements underpins the development of markers and maps of heat tolerance across seascapes and ocean warming scenarios

Moving beyond CAD to an object-oriented approach for electrical control and instrumentation systems

The quality of computer-aided-design (CAD) generated 'As-built' documentation is evaluated for a High Voltage Switchgear System (HVSS), which forms part of a Supervisory Control and Data Acquisition up-grade within a geo-thermal power plant. A total of 267 CAD drawings for the HVSS were used to create a Systems Information Model (SIM) whereby the physical components and associated connections were constructed in an object orientated database. Throughout the modelling process a considerable amount of errors and information redundancy were identified and examples are presented. The production of the CAD drawings took 10,680 man-h in stark contrast to the 80 man-h required to construct the SIM, illustrating the efficiency and effectiveness of SIM compared to CAD for the documentation of electrical instrumentation and control systems (EICS). To realise this significant potential cost and productivity saving requires a shift in mindset and a move beyond the use of CAD, to an object oriented SIM, with a 1:1 relationship between objects in the model, and components in the real world. © 2016 Elsevier Ltd. All rights reserved

Coupled Bose-Einstein condensate: Collapse for attractive interaction

We study the collapse in a coupled Bose-Einstein condensate of two types of bosons 1 and 2 under the action of a trap using the time-dependent Gross-Pitaevskii equation. The system may undergo collapse when one, two or three of the scattering lengths $a_{ij}$ for scattering of boson $i$ with $j$, $i,j = 1, 2$, are negative representing an attractive interaction. Depending on the parameters of the problem a single or both components of the condensate may experience collapse.Comment: 5 pages and 9 figures, small changes mad

The Role of Executive Functions in Socioeconomic Attainment Gaps: Results From a Randomized Controlled Trial

The socioeconomic attainment gap in mathematics starts early and increases over time. This study aimed to examine why this gap exists. Four‐year‐olds from diverse backgrounds were randomly allocated to a brief intervention designed to improve executive functions (N = 87) or to an active control group (N = 88). The study was preregistered and followed CONSORT guidelines. Executive functions and mathematical skills were measured at baseline, 1 week, 3 months, 6 months, and 1 year posttraining. Executive functions mediated the relation between socioeconomic status and mathematical skills. Children improved over training, but this did not transfer to untrained executive functions or mathematics. Executive functions may explain socioeconomic attainment gaps, but cognitive training directly targeting executive functions is not an effective way to narrow this gap

System information modelling in practice: Analysis of tender documentation quality in a mining mega-project

The quality of information contained in tender documentation produced using Computer-Aided-Design (CAD) and provided in a hard-copy format to an electrical engineering contractor for a port expansion facility, which formed an integral part of an Iron Ore mega-project is analyzed. A System Information Model (SIM), which is an object oriented approach, was retrospectively constructed from the documentation provided to assist the contractor with their tender bid preparation. During the creation of the SIM, a total of 426 errors and omissions were found to be contained within the 77 tender ‘drawing’ documents supplied to the contractor by an Engineering, Construction, Procurement and Management (EPCM). Surprisingly, 70 drawings referenced in the tender documentation, and the Input/Output lists and Cause/Effect drawings were not provided. Yet, the electrical contractor was required by the EPCM organization to provide a lump sum bid and also guarantee the proposed schedule would be met; the financial risks were too high and as a result the contractor decided not to submit a bid. It is suggested that if the original tender documentation had been prepared using a SIM rather than CAD, the quality of information presented to the contractor would have enabled them to submit a competitive bid for the works. The research concludes that the economic performance and productivity of mining projects can be significantly improved by using a SIM to engineer and document electrical instrumentation and control (EIC) systems

Chaos Theory: Implications for Cost Overrun Research in Hydrocarbon Megaprojects

Cost overruns are a recurrent problem in hydrocarbon (oil and gas) megaprojects. An understanding of why and how they occur is needed if they are to be mitigated; such knowledge can provide managers with the foundations to develop techniques to reduce and contain their negative impacts on a project’s performance. This paper examines the nature of cost overruns in hydrocarbon megaprojects using the theoretical lens of chaos theory. The underlying principles of chaos theory are reviewed and its research implications for examining cost overruns identified. By viewing megaprojects as chaotic or dynamic systems, the industry and research community may be better positioned to develop innovative solutions to mitigate cost overrun occurrence

Differential expression of ADAMTS -1, -4, -5 and TIMP -3 in rat spinal cord at different stages of acute experimental autoimmune encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE) is an animal model of inflammatory demyelination, a pathological event common to multiple sclerosis (MS). During CNS inflammation there are alterations in the extracellular matrix (ECM). A Disintegrin and Metalloproteinase with Thrombospondin motifs (ADAMTS) -1, -4 and -5 are proteases present in the CNS, which are able to cleave the aggregating chondroitin sulphate proteoglycans, aggrecan, phosphacan, neurocan and brevican. It is therefore important to investigate changes in their expression in different stages of EAE induction. We have investigated expression of ADAMTS-1, -4, -5 and Tissue inhibitor of metalloproteinase (TIMP) -3, by real-time RT-PCR. We have also examined protein expression of ADAMTS-1, -4 and -5 by western blotting and immunocytochemistry in spinal cord from animals at different stages of disease progression. Our study demonstrated a decrease in ADAMTS-4 mRNA and protein expression. TIMP-3 was decreased at the mRNA level although protein levels were increased in diseased animals compared to controls. Our study identifies changes in ADAMTS expression during the course of CNS inflammation which may contribute to ECM degradation and disease progression.</p