Molecular dynamics simulation of nanoindentation of Fe3C and tetrahedral Fe4C

Study of nanomechanical response of iron carbides is important because presence of iron carbides greatly influences the performance and longevity of steel components. This work contributes to the literature by exploring nanoindentation of nanocrystalline Fe3C and tetrahedral-Fe4C using molecular dynamics simulation. The chemical interactions of iron and carbon were described through an analytical bond order inter-atomic potential (ABOP) energy function. The indentations were performed at an indentation speed of 50 m/sec and a repeat trial was performed at 5 m/sec. Load-displacement (P-h) curve for both these carbides showed residual indentation depth and maximum indentation depth (hf/hmax) ratio to be higher than 0.7 i.e. a circumstance where Oliver and Pharr method was not appropriate to be applied to evaluate the material properties. Alternate evaluation revealed Fe3C to be much harder than Fe4C. Gibbs free energy of formation and radial distribution function, coupled with state of the average local temperature and von Mises stresses indicate the formation of a new phase of iron-carbide. Formation of this newer phase was found to be due to deviatoric strain rather than the high temperature induced in the substrate during nanoindentation

Nonlinear optics from an ab initio approach by means of the dynamical Berry phase: Application to second- and third-harmonic generation in semiconductors

We present an ab initio real-time-based computational approach to study nonlinear optical properties in condensed matter systems that is especially suitable for crystalline solids and periodic nanostructures. The equations of motion and the coupling of the electrons with the external electric field are derived from the Berry-phase formulation of the dynamical polarization [Souza et al., Phys. Rev. B 69, 085106 (2004)]. Many-body effects are introduced by adding single-particle operators to the independent-particle Hamiltonian. We add a Hartree operator to account for crystal local effects and a scissor operator to correct the independent particle band structure for quasiparticle effects. We also discuss the possibility of accurately treating excitonic effects by adding a screened Hartree-Fock self-energy operator. The approach is validated by calculating the second-harmonic generation of SiC and AlAs bulk semiconductors: an excellent agreement is obtained with existing ab initio calculations from response theory in frequency domain [Luppi et al., Phys. Rev. B 82, 235201 (2010)]. We finally show applications to the second-harmonic generation of CdTe and the third-harmonic generation of Si. 

Probing charge screening dynamics and electrochemical processes at the solid–liquid interface with electrochemical force microscopy

The presence of mobile ions complicates the implementation of voltage-modulated scanning probe microscopy techniques such as Kelvin probe force microscopy (KPFM). Overcoming this technical hurdle, however, provides a unique opportunity to probe ion dynamics and electrochemical processes in liquid environments and the possibility to unravel the underlying mechanisms behind important processes at the solid–liquid interface, including adsorption, electron transfer and electrocatalysis. Here we describe the development and implementation of electrochemical force microscopy (EcFM) to probe local bias- and time-resolved ion dynamics and electrochemical processes at the solid–liquid interface. Using EcFM, we demonstrate contact potential difference measurements, consistent with the principles of open-loop KPFM operation. We also demonstrate that EcFM can be used to investigate charge screening mechanisms and electrochemical reactions in the probe–sample junction. We further establish EcFM as a force-based imaging mode, allowing visualization of the spatial variability of sample-dependent local electrochemical properties.

Towards groundwater security in coastal East Africa: initiating a regional research network and integrated hydrogeologic, climatic & socio-economic observatories in coastal aquifers of the Comoros Islands, Kenya and Tanzania

African coastal regions are expected to experience the highest rates of population growth in coming decades. Fresh groundwater resources in the coastal zone of East Africa (EA) are highly vulnerable to seawater intrusion. Increasing water demand is leading to unsustainable and ill-planned well drilling and abstraction. Wells supplying domestic, industrial and agricultural needs are or have become, in many areas, too saline for use. Climate change, including weather changes and sea level rise, is expected to exacerbate this problem. The multiplicity of physical, demographic and socio-economic driving factors makes this a very challenging issue for management. At present the state and probable evolution of coastal aquifers in EA are not well documented. The UPGro project 'Towards groundwater security in coastal East Africa' brings together teams from Kenya, Tanzania, Comoros Islands and Europe to address this knowledge gap. An integrative multidisciplinary approach, combining the expertise of hydrogeologists, hydrologists and social scientists, is investigating selected sites along the coastal zone in each country. Hydrogeologic observatories have been established in different geologic and climatic settings representative of the coastal EA region, where focussed research will identify the current status of groundwater and identify future threats based on projected demographic and climate change scenarios. Researchers are also engaging with end users as well as local community and stakeholder groups in each area in order to understanding the issues most affecting the communities and searching sustainable strategies for addressing these.

Catholics, Science and Civic Culture in Victorian Belfast

The connections between science and civic culture in the Victorian period have been extensively, and intensively, investigated over the past several decades. Limited attention, however, has been paid to Irish urban contexts. Roman Catholic attitudes towards science in the nineteenth century have also been neglected beyond a rather restricted set of thinkers and topics. This paper is offered as a contribution to addressing these lacunae, and examines in detail the complexities involved in Catholic engagement with science in Victorian Belfast. The political and civic geographies of Catholic involvement in scientific discussions in a divided town are uncovered through an examination of five episodes in the unfolding history of Belfast's intellectual culture. The paper stresses the importance of attending to the particularities of local politics and scientific debate for understanding the complex realities of Catholic appropriations of science in a period and urban context profoundly shaped by competing political and religious factions. It also reflects more generally on how the Belfast story supplements and challenges scholarship on the historical relations between Catholicism and science.

A European Culture War in the Twentieth Century? Antic-Catholicism and Anti-Bolshevism between Moscow, Berlin, and the Vatican 1922 to 1933

The term “culture war” has become a generic expression for secular-catholic conflicts across nineteenth-century Europe. Yet, if measured by acts of violence, anticlericalism peaked in the years between 1927 and 1939, when thousands of Catholic priests and believers were imprisoned or executed and hundreds of churches razed in Mexico, Spain and Russia. This essay argues that not only in these three countries, but indeed across Europe a culture war raged in the interwar period. It takes, as a case study, the interaction of communist and Catholic actors located in the Vatican, the Soviet Union, and Germany in the period between the beginning of the Pontificate of Pius XI in 1922 and Hitler’s appointment as chancellor of Germany in 1933. Using correspondence and reports from the Vatican archives, this essay shows how Papal officials and communist leaders each sought to mobilize the German populace to achieve their own diplomatic ends. German Catholics and communists gladly responded to the call to arms that sounded from Rome and Moscow in 1930, but they did so also to further their own domestic goals. The case study shows how national contexts inflected the transnational dynamics of radical anti-Catholicism in interwar Europe. In the end, agitation against “godlessness” did not lead to the return of a “Christian State” desired by many conservative Christians. Instead, the culture war further destabilized the republic and added a religious dimension to a landscape well suited to National Socialist efforts to reach a Christian population otherwise mistrustful of its völkisch and anticlerical elements.

Cities and The Spirit Level: Reasserting the Public Interest in Planning Governance

Urban planning in Europe has its roots in social reform movements for reform of the 18th and 19th centuries and in the UK evolved into the state-backed comprehensive planning system established as a pillar of the welfare state in 1947. This new planning system played a key role in meeting key social needs of the early post-war period, through, for example, an ambitious new town programme. However, from the late 1970s onwards the main priorities of the planning system have shifted as the UK state has withdrawn support for welfare and reasserted market values. One consequence of this has been an increased inequality in access to many of the resources that planning seeks to regulate, including affordable housing, local services and environmental quality.
Drawing on evidence from recent literature on equality, including Wilkinson and Pickett’s The Spirit Level this paper will question the role of planning in an era of post-politics and a neo-liberal state. It will review some of the consequences for the governance and practice of planning and question what this means for the core values of the planning profession. Finally, the paper will discuss the rise of the Healthy Urban Planning Movement in the US and Europe and ask whether this provides any potential for reasserting the public interest in planning process.

Intraoperative radiotherapy in early stage breast cancer: potential indications and evidence to date

Following early results of recent studies of intra-operative radiotherapy (IORT) in the adjuvant treatment of patients with early breast cancer, the clinical utility of IORT is a subject of much recent debate within the breast oncology community. This review describes the intra-operative techniques available, the potential indications, and the evidence to date pertaining to local control and toxicity. We also discuss any implications for current practice and future research.

Review of Legislation and Policy Guidance relating to Adult Social Care in Northern Ireland

Introduction and Background

This research was undertaken by an international team of academics from Queen’s University, Belfast, Leeds University and Penn State University (USA) who have examined models of adult social care provision across thirteen jurisdictions. The aim of this research is to present the Commissioner for Older People in Northern Ireland (COPNI) with possible options for legal reform to adult social care provision for older people in Northern Ireland.

Project Objectives

The agreed objectives of this research were to provide:
• Identification of gaps and issues surrounding the current legislative framework including policy provision for adult social care in Northern Ireland.
• Comparison of Northern Ireland with best practice in other jurisdictions to include (but not be limited to): England and Wales, Republic of Ireland, Scotland and at least two other international examples; Recommendations, based on the above, as to whether there is a need for legislative reform – provision of suggestions other than legislative change (if applicable).
• Recommendations or options based on the above, on how to best change the current framework in Northern Ireland to provide better support outcomes for older people.
• Stakeholder engagement via roundtable event to discuss outcomes/ recommendations.

Structure of Report

The findings from this research are based on an international review of adult social care in the local, national and international contexts. The report will, therefore, firstly present the key recommendations for Northern Ireland which have emerged from a systematic examination and review of adult social care in diverse jurisdictions. Each jurisdiction is then examined in the context of legislative and policy provision and examples of best practice are provided. The final section of the report then compares Northern Ireland to best practice from each of these aforementioned jurisdictions and the discussion entails the background to the report’s final Recommendations. The recommendations in this report are thus directly linked in with the evidence we have gathered across different countries with contrasting systems of welfare.

Aspirin and folic acid for the prevention of recurrent colorectal adenomas

BACKGROUND & AIMS: Although observational studies have found regular aspirin use to be associated with a reduced risk of colorectal neoplasia, results from randomized trials using aspirin have been inconsistent. Dietary folate intake also has been found to be associated with a reduced risk of colorectal neoplasms in observational studies.

METHODS: A multicenter, randomized, double-blind trial of aspirin (300 mg/day) and folate supplements (0.5 mg/day) to prevent colorectal adenoma recurrence was performed using a 2 x 2 factorial design. All patients had an adenoma (>/=0.5 cm) removed in the 6 months before recruitment and were followed-up at 4-month intervals with a second colonoscopy after approximately 3 years. The primary outcome measure was a colorectal adenoma diagnosed after baseline.

RESULTS: A total of 945 patients were recruited into the study, of whom 853 (90.3%) underwent a second colonoscopy. In total, 99 (22.8%) of 434 patients receiving aspirin had a recurrent adenoma compared with 121 (28.9%) of 419 patients receiving placebo (relative risk, 0.79; 95% confidence interval [CI], 0.63-0.99). A total of 104 patients developed an advanced colorectal adenoma; 41 (9.4%) of these were in the aspirin group and 63 (15.0%) were in the placebo group (relative risk, 0.63; 95% CI, 0.43-0.91). Folate supplementation was found to have no effect on adenoma recurrence (relative risk, 1.07; 95% CI, 0.85-1.34).

CONCLUSIONS: Aspirin (300 mg/day) but not folate (0.5 mg/day) use was found to reduce the risk of colorectal adenoma recurrence, with evidence that aspirin could have a significant role in preventing the development of advanced lesions.

Special condition wind power forecasting based on Gaussian process and similar historical data

Due to the variability of wind power, it is imperative to accurately and timely forecast the wind generation to enhance the flexibility and reliability of the operation and control of real-time power. Special events such as ramps, spikes are hard to predict with traditional methods using solely recently measured data. In this paper, a new Gaussian Process model with hybrid training data taken from both the local time and historic dataset is proposed and applied to make short-term predictions from 10 minutes to one hour ahead. A key idea is that the similar pattern data in history are properly selected and embedded in Gaussian Process model to make predictions. The results of the proposed algorithms are compared to those of standard Gaussian Process model and the persistence model. It is shown that the proposed method not only reduces magnitude error but also phase error.

Reaching out: medical students leading in local communities

Background: Queen's University Red Cross is a medical student-led volunteer group with a key aim of promoting social change within local communities and empowering young people to aspire to higher education. We describe ‘The Personal Development Certificate’, a 12–week community development programme devised by third-year medical students at Queen's University Belfast to target young people who are lacking educational motivation, are disengaged at home or are marginalised through social circumstances.

Context: Community-based education is of increasing importance within undergraduate and postgraduate medical education in the UK, and further afield. We evaluated the perceived improvements in key skills such as teamwork, leadership, communication, and problem solving in students following participation in this programme, and the extent to which their attitude and appreciation of community-based medicine changed.

Innovation: Following facilitation of this community-based initiative, all students reported a perceived improvement in the acquired skill sets. Students made strong links from this programme to previous clinical experiences and appreciated the opportunity to translate a series of classroom-learned skills to real-life environments and interactions. The students’ appreciation and understanding of community-based medicine was the single most improved area of our evaluation.

Implications: We have demonstrated that medical students possess the skills to develop and facilitate their own educational projects. Non-clinical, student-led community projects have the potential to be reproduced using recognised frameworks and guidelines to complement the current undergraduate medical curriculum

Quantifying heritable variation in fitness-related traits of wild, farmed and hybrid Atlantic salmon families in a wild river environment

Farmed fish are typically genetically different from wild conspecifics. Escapees from fish farms may contribute one-way gene flow from farm to wild gene pools, which can depress population productivity, dilute local adaptations and disrupt coadapted gene complexes. Here, we reanalyse data from two experiments (McGinnity et al., 1997, 2003) where performance of Atlantic salmon (Salmo salar) progeny originating from experimental crosses between farm and wild parents (in three different cohorts) were measured in a natural stream under common garden conditions. Previous published analyses focussed on group-level differences but did not account for pedigree structure, as we do here using modern mixed-effect models. Offspring with one or two farm parents exhibited poorer survival in their first and second year of life compared with those with two wild parents and these group-level inferences were robust to excluding outlier families. Variation in performance among farm, hybrid and wild families was generally similar in magnitude. Farm offspring were generally larger at all life stages examined than wild offspring, but the differences were moderate (5–20%) and similar in magnitude in the wild versus hatchery environments. Quantitative genetic analyses conducted using a Bayesian framework revealed moderate heritability in juvenile fork length and mass and positive genetic correlations (>0.85) between these morphological traits. Our study confirms (using more rigorous statistical techniques) previous studies showing that offspring of wild fish invariably have higher fitness and contributes fresh insights into family-level variation in performance of farm, wild and hybrid Atlantic salmon families in the wild. It also adds to a small, but growing, number of studies that estimate key evolutionary parameters in wild salmonid populations. Such information is vital in modelling the impacts of introgression by escaped farm salmon.

Employers, trade unions and concession bargaining in the Irish recession

The issue of concession bargaining between employers and unions during the Great Recession has received little attention in the research literature. This article presents a systematic analysis of the conduct of concession bargaining during the recession in Ireland in the context of three forms of concession bargaining identified in the international literature: integrative concession bargaining, distributive concession bargaining and ultra concession bargaining – each with different but overlapping sets of institutional foundations and implications for employers and trade unions. Drawing on focus groups of managers and union officials and a representative survey of employers, the article shows that distributive concession bargaining has been the predominant form in the Irish recession. This form of concession bargaining is likely to have few lasting direct effects on employer or union roles in collective bargaining but nevertheless appears to have significant indirect implications for the silent marginalization of unions in workplaces.

Producing and Governing Community (Through) Resilience

This article argues that the UK government’s Community Resilience programme is less about responding to disasters and more a matter of producing community and governing its behaviour. The passing over of responsibility to local volunteers and organisations is not only about empowerment, but forming identities and relationships that can be more efficiently managed and directed. However, this attempt is hamstrung by its basis in a nostalgic, romantic view of community and the effacement of poverty and inequality as central to the vulnerability/resilience binary. The effect may be a more intense government of communities rather than their empowerment through resilience.