Studies of the double-layer and exchange reactions at copper and cadmium electrodes

The structures of the electrical double layers at some metal/aqueous solution interphases have been studied. The kinetics of the exchange reactions at copper and cadmium electrodes have been investigated in selected electrolytes using a.c. impedance and galvanostatic techniques. The contributions by various possible steps to the overall exchange process have been investigated. In nitrate electrolyte (NO-3 not adsorbed) the component process controlling the rate of exchange at copper electrodes is shown (at ≈ 40°C) to change from crystallisation (and dissolution of the lattice) to charge transfer. In sulphate electrolytes (SO2-4 adsorbed at the electrode) the control is solely by the processes of crystallisation (and dissolution of the lattice). The exchange process at a cadmium electrode system was found to be difficult to study in aqueous solution. The system is very susceptible to interference from impurities in the electrolyte. In NaClO4 electrolyte the exchange process is controlled by crystallisation (and dissolution) effects. In alkaline electrolytes the exchange reaction is a very rapid process. In this case however, it is likely that the exchange proceeds via a surface film and there is no evidence for any crystallisation effects. For some metals, the mechanism of the exchange process (i.e. whether the reaction proceeds by surface diffusion or direct transfer to a kink site across the double layer) has been discussed in connection with the crystal structure

Tomato spotted wilt virus and its management

In 1993, western flower thrips, an important pest of horticultural crops, was found in Western Australia. Since then there has been an upsurge in damsging virus disease epidemics caused by tomato spotter wilt virus in horticultural crops. This has occurred because western flower thrips is a more effective vector of tomato spotted wilt virus than other thrips species. Lindrea Latham and Roger Jones outline the symptoms, spread and management of this serious virus disease in vegetables and ornamentals

Biomedical Applications of Batteries

An overview is presented of the many ways in which batteries and battery materials are used in medicine and in biomedical studies. These include the use of batteries as power sources for motorised wheelchairs, surgical tools, cardiac pacemakers and defibrillators, dynamic prostheses, sensors and monitors for physiological parameters, neurostimulators, devices for pain relief, and iontophoretic, electroporative and related devices for drug administration. The various types of battery and fuel cell used for this wide range of applications will be considered, together with the potential harmful side effects, including accidental ingestion of batteries and the explosive nature of some of the early cardiac pacemaker battery systems

A biogeochemical analysis of the Pocono till barrens and adjacent hardwood forest underlain by Wisconsinan and Illinoian till in northeastern Pennsylvania

We assessed soil and vegetation nutrient capital in the landscape mosaic of till barrens and hardwood forests on the Pocono Plateau in northeastern Pennsylvania. These shrublands, which contain an unusual abundance of rare species, occur primarily on Illinoian-aged glacial till, though some patches grow on Wisconsinan till. We hypothesized that barrens soil and vegetation contain smaller quantities of nutrients than forest soil and vegetation, and under the same vegetation, Illinoian till soils have a smaller nutrient content than Wisconsinan till soils. We measured pH, total C and N, and exchangeable Ca, Mg, K, and Al content of the soils and determined C, N, Ca, Mg, K, and P content of the vegetation. Litter and soil organic matter in the barrens have a higher C/N ratio than the forest. The Illinoian barrens Oa horizon is thicker and contains a greater quantity of exchangeable mineral nutrients than the other Oa horizons. Differences in vegetation nutrient capital strongly mirror differences in biomass. Our results show no strong association of parent material with soil or vegetation nutrient capital. Instead, they suggest that plant community characteristics, not soil nutrient availability, shape the landscape pattern of barrens and forest, particularly plant-driven positive feedbacks primarily involving fire frequency

Polymer electrolytes based on modified natural rubber

Modified natural rubber polymer hosts having low transition glass temperatures have been investigated for use in polymer electrolytes. Two types of modified natural rubber, namely 25% epoxidised natural rubber (ENR-25) and 50% epoxidised natural rubber (ENR-50) were employed in conjunction with poly(ethylene oxide), PEO. Results are reported for ionic conductivity and thermal properties for both unplasticized and plasticized polymer electrolyte systems with lithium triflate. The samples were in the form of free standing films with the thickness 0.2–0.5 mm and mixtures of ethylene carbonate (EC) and propylene carbonate (PC) were used as plasticizers. Unplasticized modified natural rubber-based systems exhibit ionic conductivities in the range 10−6 to 10−5 S cm−1 at ambient temperatures. Incorporating 100% of EC/PC by weight fraction of polymer (ENR/PEO) to the systems yielded mechanically stable films and ionic conductivities in the range of 10−4 S cm−1 at ambient temperature

Talking with strangers: towards a Christian, postmodern, academic model for biblical interpretation

Postmodernism in Biblical Studies is characterised by proliferation of methodological and ideological interpretive perspectives, emphasis upon the ethics of interpretation and awareness of the role of interpretive communities. Following Stephen E. Fowl, the underlying motives of interpreters can be understood when approaches are analysed in terms of interpretive interests. The work of David J. A. Clines, J. Cheryl Exum and Stephen D. Moore reveals a strong de-confessional motive and a desire to exclude confessional concerns from academic interpretation. This position is ideologically driven and, in terms of liberal academic values, self-contradictory. The difficulties posed for Christian interpretation by the postmodern context are evident in the narrative criticism of Mark Allan Powell and R. Alan Culpepper, where unresolved conflict of theological, methodological and political interests threatens the coherence of the approach. Recent work by Powell addresses postmodern concerns, but fails adequately to engage theoretical and theological issues. A postmodern understanding of the Bible as Christian scripture which affirms both the validity and legitimacy of multiple interpretive perspectives and a pneumatological understanding of the Bible as the Word of God can be framed using the work of Kevin J. Vanhoozer, Stephen E. Fowl, Roman Jakobson and Daniel Patte. Socio-pragmatic objections to the legitimacy and validity of Christian interpretation beyond the faith community can be resisted by asserting a dialogical relationship between the Bible, the church and the wider academic community, and by following Francis Watson’s argument that the church’s discourse is derived from that of the wider society in which it exists. Christian interpretation will seek to engage constructively with other interpretive approaches. A Christian ethics of interpretation characterised by openness, humility, repentance and forgiveness offers a positive contribution to the culture of postmodern academic interpretation. Jesus’ encounter with the Syrophoenician woman in Mark 7 offers a paradigm for such interpretive practice

Line Broadening in Field Metal-poor Red Giant and Red Horizontal Branch Stars

We report 349 radial velocities for 45 metal-poor field red giant and red horizontal branch stars. We have have identified one new spectroscopic binary, HD 4306, and one possible such system, HD 184711. We also report 57 radial velocities for 11 of the 91 stars reported on previously by Carney et al. (2003). As was found in the previous study, radial velocity "jitter" is present in many of the most luminous stars. Excluding stars showing spectroscopic binary orbital motion, all 7 of the red giants with M(V) <= -2.0 display jitter, as well as 3 of the 14 stars with -2.0 <= M(V) <= -1.4. We have also measured line broadening in all of the new spectra, using synthetic spectra as templates. The most luminous red giants show significant line broadening, as do many of the red horizontal branch stars, and we discuss briefly possible causes.Comment: To appear in the Astronomical Journa

A ReaXFF carbon potential for radiation damage studies

Although molecular dynamics simulations of energetic impacts and collision cascades in graphite have been investigated for over 25 years, recent investigations have shown a difference between the types of defects predicted by the commonly used empirical potentials compared to ab-initio calculations. As a result a new ReaXFF potential has been fitted which reproduces the formation energies of many of the defects predicted by the ab-initio calculations and the energy pathways between different defect states, important for investigating long term defect evolution. The data sets in the fitting have been have been added to the existing data sets used for modelling hydrocarbons and fullerenes. The elastic properties of the potential are less well modelled than the point defect structures with the elastic constants c33 being too high and c44 too low compared to experiment. Preliminary results of low energy collision cascades show many point defect structures develop that are in agreement with those predicted from the ab-initio results

The mental health of NHS staff during the COVID-19 pandemic:Two-wave Scottish cohort study

Background: Health and social care workers (HSCWs) are at risk of experiencing adverse mental health outcomes (e.g. higher levels of anxiety and depression) because of the COVID-19 pandemic. This can have a detrimental effect on quality of care, the national response to the pandemic and its aftermath. Aims: A longitudinal design provided follow-up evidence on the mental health (changes in prevalence of disease over time) of NHS staff working at a remote health board in Scotland during the COVID-19 pandemic, and investigated the determinants of mental health outcomes over time. Method: A two-wave longitudinal study was conducted from July to September 2020. Participants self-reported levels of depression (Patient Health Questionnaire-9), anxiety (Generalised Anxiety Disorder-7) and mental well-being (Warwick-Edinburgh Mental Well-being Scale) at baseline and 1.5 months later. Results: The analytic sample of 169 participants, working in community (43%) and hospital (44%) settings, reported substantial levels of depression and anxiety, and low mental well-being at baseline (depression, 30.8%; anxiety, 20.1%; well-being, 31.9%). Although mental health remained mostly constant over time, the proportion of participants meeting the threshold for anxiety increased to 27.2% at follow-up. Multivariable modelling indicated that working with, and disruption because of, COVID-19 were associated with adverse mental health changes over time. Conclusions: HSCWs working in a remote area with low COVID-19 prevalence reported substantial levels of anxiety and depression, similar to those working in areas with high COVID-19 prevalence. Efforts to support HSCW mental health must remain a priority, and should minimise the adverse effects of working with, and disruption caused by, the COVID-19 pandemic