A selected ion flow tube study of the ion-molecule reactions of monochloroethene, trichloroethene and tetrachloroethene

Data for the rate coefficients and product cations of the reactions of a large number of atomic and small molecular cations with monochloroethene, trichloroethene and tetrachloroethene in a selected ion flow tube at 298 K are reported. The recombination energy of the ions range from 6.27 eV (H$_3$O$^+$) through to 21.56 eV (Ne$^+$). Collisional rate coefficients are calculated by modified average dipole orientation theory and compared with experimental values. Thermochemistry and mass balance predict the most feasible neutral products. Together with previously reported results for the three isomers of dichloroethene (J. Phys. Chem. A., 2006, 110, 5760), the fragment ion branching ratios have been compared with those from threshold photoelectron photoion coincidence spectroscopy over the photon energy range 9-22 eV to determine the importance or otherwise of long-range charge transfer. For ions with recombination energy in excess of the ionisation energy of the chloroethene, charge transfer is energetically allowed. The similarity of the branching ratios from the two experiments suggest that long-range charge transfer is dominant. For ions with recombination energy less than the ionisation energy, charge transfer is not allowed; chemical reaction can only occur following formation of an ion-molecule complex, where steric effects are more significant. The products that are now formed and their percentage yield is a complex interplay between the number and position of the chlorine atoms with respect to the C=C bond, where inductive and conjugation effects can be important

Telemedicine interventions in six conflict-affected countries in the WHO Eastern Mediterranean region: a systematic review

Background: The COVID-19 pandemic has escalated the use of telemedicine in both high and low resource settings however its use has preceded this, particularly in conflict-affected settings. Several countries in the WHO Eastern Mediterranean (EMR) region are affected by complex, protracted crises. Though telemedicine has been used in such settings, there has been no comprehensive assessment of what interventions are used, their efficacy, barriers, or current research gaps. Objectives: To perform a systematic review of academic and grey literature, identifying telemedicine interventions in select, EMR conflict-affected settings and relevant enablers and barriers to their implementation. Methods: A systematic search of ten academic databases and 3 grey literature sources from January 1st 2000 to December 31st 2020 was completed. Included articles reported on telemedicine use in six conflict-affected EMR countries (or territories) graded as WHO Health Emergencies: Afghanistan, Gaza, Iraq, Libya, Syria and Yemen. Data were extracted and narratively synthesised due to heterogeneity in study design and outcomes. Results: Of 3419 articles identified, twenty-one peer-reviewed and three grey literature sources met the inclusion criteria. We analysed these by context, intervention, and evaluation. Context: eight related to Afghanistan, eight to Syria and seven to Iraq with one each in Yemen and Gaza. Most were implemented by humanitarian or academic organisations with projects mostly initiated in the United States or Europe and mostly by physicians. The in-country links were mostly health professionals rather than patients seeking specialist inputs for specialities not locally available. Interventions: These included both SAF (store and forward) and RT (real-time) with a range of specialities represented including radiology, histopathology, dermatology, mental health, and intensive care. Evaluation: most papers were observational or descriptive with few describing quality measures of interventions. Conclusions: Telemedicine interventions are feasible in conflict-affected settings in EMR using low-cost, accessible technologies. However, few implemented interventions reported on evaluation strategies or had these built in. The ad hoc nature of some of the interventions, which relied on volunteers without sustained financial or academic investment, could pose challenges to quality and sustainability. There was little exploration of confidentiality, ethical standards, data storage or local healthcare worker and patient acceptability

Influence of subunit structure on the oligomerization state of light harvesting complexes: a free energy calculation study

Light harvesting complexes 2 (LH2) from Rhodospirillum (Rs.) molischianum and Rhodopseudomonas (Rps.) acidophila form ring complexes out of eight or nine identical subunits, respectively. Here, we investigate computationally what factors govern the different ring sizes. Starting from the crystal structure geometries, we embed two subunits of each species into their native lipid-bilayer/water environment. Using molecular dynamics simulations with umbrella sampling and steered molecular dynamics, we probe the free energy profiles along two reaction coordinates, the angle and the distance between two subunits. We find that two subunits prefer to arrange at distinctly different angles, depending on the species, at about 42.5 deg for Rs. molischianum and at about 38.5 deg for Rps. acidophila, which is likely to be an important factor contributing to the assembly into different ring sizes. Our calculations suggest a key role of surface contacts within the transmembrane domain in constraining these angles, whereas the strongest interactions stabilizing the subunit dimers are found in the C-, and to a lesser extent, N-terminal domains. The presented computational approach provides a promising starting point to investigate the factors contributing to the assembly of protein complexes, in particular if combined with modeling of genetic variants.Comment: 28 pages, 7 figures, LaTeX2e - requires elsart.cls (included), submitted to Chemical Physic

Young people, inequality and violence during the COVID-19 lockdown in Uganda

This working paper reports findings from a qualitative study on how response measures during the early stages of the COVID-19 pandemic in Uganda have affected the lives of adolescent young people. The study was conducted as part of a broader research project: Contexts of Violence in Adolescence Cohort Study (CoVAC), with data collected through mobile phone interviews in May-June 2020 with 18 girls and 16 boys (mainly aged 16-19 years) who have been participants in our longitudinal study. The data are contextualized within longitudinal biographical narratives of these young people that have been developed since 2018 and which helped us to illuminate the significance of the crisis in their everyday lives. The analysis shows how effects on young people of the lockdown varied according to gender, location, mobility and socio-economic background, amplifying inequalities and creating the conditions for multiple forms of violence

Reduction of Couplings in Quantum Field Theories with applications in Finite Theories and the MSSM

We apply the method of reduction of couplings in a Finite Unified Theory and in the MSSM. The method consists on searching for renormalization group invariant relations among couplings of a renormalizable theory holding to all orders in perturbation theory. It has a remarkable predictive power since, at the unification scale, it leads to relations between gauge and Yukawa couplings in the dimensionless sectors and relations involving the trilinear terms and the Yukawa couplings, as well as a sum rule among the scalar masses and the unified gaugino mass in the soft breaking sector. In both the MSSM and the FUT model we predict the masses of the top and bottom quarks and the light Higgs in remarkable agreement with the experiment. Furthermore we also predict the masses of the other Higgses, as well as the supersymmetric spectrum, both being in very confortable agreement with the LHC bounds on Higgs and supersymmetric particles.Comment: 18 pages, 4 figures. To appear in the proceedings of LT-10, Varna. Based on invited talks given at: LT-10, Varna; PACT-2013, Madrid; SQS'2013, Dubna; CORFU 2013, Corfu, and in several invited seminar

Experimental study of the effect of C8 oxygenates on sooting processes in high pressure spray flames

© 2020 The Authors. Oxygenated compounds have the ability to reduce soot emissions and to improve the combustion efficiency in engines. Most studies have focused on the soot reduction potential of shorter carbon chain oxygenates, whilst longer carbon chain oxygenates are still relatively unexplored. In this work, the soot reduction potential of long carbon chain oxygenates having similar thermo-physical and chemical properties to those of diesel have been studied, viz., 2-octanone (ketone), 1-octanol (alcohol), hexyl acetate (ester) and octanal (aldehyde). These oxygenates were injected at high pressure into a constant volume chamber maintained at high ambient temperature conditions, and their spray flames were investigated using a high-speed, two-colour pyrometry system. It was found that for the same injected fuel mass, the oxygenates reduced the overall soot when compared to diesel. Small differences in sooting tendencies were observed between different oxygenated moieties but these were smaller than those relative to diesel. The absence of aromatic groups and the presence of oxygen directly bonded to carbon atoms seemed to have a larger effect on soot reduction than the oxygenated functional group. The oxygenates altered the local oxygen equivalence ratio in the spray, influencing the soot formation and its distribution in the flame. Under the high pressure conditions studied, the average sooting tendency of the long carbon-chain oxygenates studied increased in the order of: ester< aldehyde ~ alcohol<ketone.Engineering and Physical Science Research Council (EPSRC

Performance of the LHCb Vertex Detector Alignment Algorithm determined with Beam Test Data

LHCb is the dedicated heavy flavour experiment at the Large Hadron Collider at CERN. The partially assembled silicon vertex locator (VELO) of the LHCb experiment has been tested in a beam test. The data from this beam test have been used to determine the performance of the VELO alignment algorithm. The relative alignment of the two silicon sensors in a module and the relative alignment of the modules has been extracted. This alignment is shown to be accurate at a level of approximately 2 micron and 0.1 mrad for translations and rotations, respectively in the plane of the sensors. A single hit precision at normal track incidence of about 10 micron is obtained for the sensors. The alignment of the system is shown to be stable at better than the 10 micron level under air to vacuum pressure changes and mechanical movements of the assembled system.Comment: accepted for publication in NIM

Evaluating the potential of a long carbon chain oxygenate (octanol) on soot reduction in diesel engines

Copyright © The Authors 2019. The automotive industries are facing challenges to meet stringent CO2 and air-quality regulations. One of the factors affecting emissions performance is the fuel’s chemical composition. The presence of oxygen in a fuel offers the potential to lower soot emissions, however, these oxygenates must be compatible with existing hardware and fuels. To this end, the combustion of a long carbon-chain oxygenate, 1-octanol, was studied. It was injected at high pressures into a constant volume chamber, and a high-speed, two-colour pyrometry system was used to evaluate the spatial and temporal variations of soot and temperature. A significant reduction of soot was obtained whilst the flame temperature remained similar to that for diesel.EPSR