Graph theory applied to plasma chemical reaction engineering

This work explores the following applications of graph theory to plasma chemical reaction engineering: assembly of a weighted directional graph with the key addition of reaction nodes, from a published set of reaction data for air; graph visualisation for probing the reaction network for potentially useful or problematic reaction pathways; running Dijkstra’s algorithm between all species nodes; further analysis of the graph for useful engineering information such as which conditions, reactions, or species could be enhanced or supressed to favour particular outcomes, e.g. targeted chemical formation. The use of reaction-nodes combined with derived parameters allowed large amounts of key information regarding the plasma chemical reaction network to be assessed simultaneously using a leading open source graph visualisation software (Gephi). A connectivity matrix of Dijkstra’s algorithm between each two species gave a measure of the relative potential of species to be created and destroyed under specific conditions. Further investigation into using the graph for key reaction engineering information led to the development of a graph analysis algorithm to quantify demand for conditions for targeted chemical formation: Optimal Condition Approaching via Reaction-In-Network Analysis (OCARINA). Predictions given by running OCARINA display significant similarities to a well-known electric field strength regime for optimal ozone production in air. Time dependent 0D simulations also showed preferential formation for O· and O3 using the respective conditions generated by the algorithm. These applications of graph theory to plasma chemical reaction engineering show potential in identifying promising simulations and experiments to devote resources

Node-of-influence network analysis for targeted condition sequencing in plasma chemical reaction networks

It was demonstrated that a plasma chemical reaction system can be represented as a directed bipartite variable-relationship (VR) graph to accurately represent node influence, and that targeted node-influence analysis of this graph can determine improved condition sequencing for a target outcome. A novel graph algorithm (OCARINA) was adapted for VR-graphs to give a measure of the net-influence of incremental increase (NIII) of one variable on another at any depth in the graph. Additionally, two conventional node-influence measures, the Eigenvector Centrality Index (ECI) and Katz Centrality Index (KCI), were also trialled on the VR-graph. The electron energy (ε) node influence was evaluated on a “baseline” continuous sequence of 10 ns 1 eV pulses in a 0D chemical-kinetic simulation using ECI, KCI and OCARINA NIII at three depths. KCI appeared to give meaningful values for ε influence in the whole graph but not on specific nodes, ECI gave no meaningful results. OCARINA (O3 targeted) suggested each successive ε pulse had diminishing influence on O3 formation, though analysis differed for each NIII depth. O3 concentrations in simulations with different numbers of ε pulses decreased with each additional pulse, correlating with the OCARINA analysis. O3, NO and O Species production in simulations of two ε pulses with one or both pulses incrementally changed by 10% from the baseline also largely agreed with the OCARINA results for each species on a baseline simulation of two consecutive 1 eV electron energy pulses. Additionally, it was found the NIII at antecedent depths corresponded to effects in subsequent phases in simulations

Improving the efficiency of high-temperature electrolysis of carbon dioxide in a solid oxide cell

This work focuses on the development of a bespoke rig which allows for the simultaneous use of non-thermal plasmas (NTPs), oscillating gas flow via a Desai-Zimmerman Fluidic Oscillator (DZFO) and a Solid Oxide Cell (SOC) to create a highly efficient energy conversion device to facilitate the reduction of CO2 to CO. Both fluidic oscillation and NTPs have the potential to reduce resistances in a SOC, key to furthering their commercialisation. The potential role of NTPs in improving the kinetics and efficiency of reactions relevant to CO2 reduction, such as the dissociation of CO2, is presented. Performance improvements using a rapidly oscillating gas flow, provided by the DZFO, to minimise concentration polarisation resistance by disrupting boundary layer formation and increasing overall efficiency are also discussed. The intersection of these technologies provide a path for a paradigm shift in the ability to convert waste CO2 into high value feedstock using renewable energy

Difference in countries' use of resources and clinical outcome for patients with cardiogenic shock after myocardial infarction: results from the GUSTO trial

BACKGROUND: Use of aggressive and invasive interventions is more common in the USA than in other countries. We have compared use of resources for patients with cardiogenic shock after myocardial infarction in the USA and in other countries, and assessed the association between use of resources and clinical outcomes. METHODS: We analysed data for patients with cardiogenic shock after myocardial infarction who were enrolled in the GUSTO-I trial (1891 treated in the USA, 1081 treated in other countries). Patients were randomly assigned combinations of streptokinase, heparin, and accelerated tissue-plasminogen activator (t-PA), then decisions about further interventions were left to the discretion of the attending physician. The interventions included in our analysis were: pulmonary-artery catheterisation, cardiac catheterisation, intravenous inotropic agents, ventilatory support, intra-aortic balloon counterpulsation (IABP), percutaneous transluminal coronary angioplasty (PTCA), and coronary bypass graft surgery (CABG). The primary outcome measure was death from any cause at 30 days of follow-up. FINDINGS: Patients who were treated in the USA were significantly younger than those treated elsewhere (median 68 [IQR 59-75] vs 70 [62-76], p < 0.001), a smaller proportion had anterior infarction (49 vs 53%, p < 0.001), and they had a shorter time to treatment (mean 3.1 vs 3.3 h, p < 0.001). Aggressive diagnostic and therapeutic procedures were used more commonly in the USA than in the other countries: cardiac catheterisation (58 vs 23%); IABP (35 vs 7%); right-heart catheterisation (57 vs 22%); and ventilatory support (54 vs 38%). 483 (26%) of the patients treated in the USA underwent PTCA, compared with 82 (8%) patients in oth

The genome of the stable fly, Stomoxys calcitrans, reveals potential mechanisms underlying reproduction, host interactions, and novel targets for pest control.

The stable fly, Stomoxys calcitrans, is a major blood-feeding pest of livestock that has near worldwide distribution, causing an annual cost of over $2 billion for control and product loss in the USA alone. Control of these flies has been limited to increased sanitary management practices and insecticide application for suppressing larval stages. Few genetic and molecular resources are available to help in developing novel methods for controlling stable flies. This study examines stable fly biology by utilizing a combination of high-quality genome sequencing and RNA-Seq analyses targeting multiple developmental stages and tissues. In conjunction, 1600 genes were manually curated to characterize genetic features related to stable fly reproduction, vector host interactions, host-microbe dynamics, and putative targets for control. Most notable was characterization of genes associated with reproduction and identification of expanded gene families with functional associations to vision, chemosensation, immunity, and metabolic detoxification pathways. The combined sequencing, assembly, and curation of the male stable fly genome followed by RNA-Seq and downstream analyses provide insights necessary to understand the biology of this important pest. These resources and new data will provide the groundwork for expanding the tools available to control stable fly infestations. The close relationship of Stomoxys to other blood-feeding (horn flies and Glossina) and non-blood-feeding flies (house flies, medflies, Drosophila) will facilitate understanding of the evolutionary processes associated with development of blood feeding among the Cyclorrhapha

Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters

Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio

Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS

The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table, corrected author list, matches final version in Physical Review Letter

Measurement of the inclusive isolated prompt photon cross-section in pp collisions at sqrt(s)= 7 TeV using 35 pb-1 of ATLAS data

A measurement of the differential cross-section for the inclusive production of isolated prompt photons in pp collisions at a center-of-mass energy sqrt(s) = 7 TeV is presented. The measurement covers the pseudorapidity ranges |eta|<1.37 and 1.52<=|eta|<2.37 in the transverse energy range 45<=E_T<400GeV. The results are based on an integrated luminosity of 35 pb-1, collected with the ATLAS detector at the LHC. The yields of the signal photons are measured using a data-driven technique, based on the observed distribution of the hadronic energy in a narrow cone around the photon candidate and the photon selection criteria. The results are compared with next-to-leading order perturbative QCD calculations and found to be in good agreement over four orders of magnitude in cross-section.Comment: 7 pages plus author list (18 pages total), 2 figures, 4 tables, final version published in Physics Letters