Fabrication of high efficiency and radiation resistant GaAs solar cells

Systematic improvements in fabrication yield were obtained by appropriate control of the liquid phase epitaxial growth process, contact fabrication and surface preparation. To improve radiation hardness, the junction depth was decreased while overcoming the penalty in decreased solar cell efficiency which tends to go hand-in-hand with the reduction of junction depth in (AlGa) As-GaAs solar cells. Cells were made with an AMO efficiency of 18% and a junction depth of 0.5 micrometers, as compared to junction depths on the order of 1.0 micrometers. With respect to the damage caused by proton irradiation, the nature of the observed damage was correlated to the energy and penetration depth of the damaging protons

Informal Learning, Practitioner Inquiry and Occupational Education An Epistemological Perspective

Informal Learning, Practitioner Inquiry and Occupational Education explores how practitioners in a variety of occupations perform their jobs and argues that working and learning are intricately connected. Drawing on theories around working and learning in informal, formal and lifelong settings, the book gives insights into how workers negotiate their occupational practices. The book investigates four related concepts – informal learning, practitioner inquiry, occupational education and epistemological perspectives. The combinations of theories and empirical case studies are used to provide a conceptual framework of inquiry where knowledge, abilities, experiences and skill sets play a significant aspect. It presents 11 case studies of professions ranging from conventional occupations of acting, detective work, international road transportation to emerging professions of boardroom consultancy, nutritional therapy and opinion leadership. This book will be of great interest for academics, scholars and postgraduate students who are engaged in the study of informal education, vocational education and occupation-related programmes. It will also offer significant insights for related education practitioners wanting to have greater understanding of their own journeys and practices

Surface coatings and catalyst production by electrodeposition

Electrodeposition and electrocodeposition in low gravity are discussed. The goal is to provide a better understanding of the role of convection and buoyancy in the mechanisms of formation of some electrodeposited surfaces, fluid flow in the vicinity of electrodepositing surfaces, the influence of a moving medium upon codeposition, the effect of gravity upon the dispersion (coagulation) of neutral particles that are desired for codeposition and preparation of improved surface coatings and metal catalysts

Spatially explicit threat assessment to target food tree species in Burkina Faso

There is a general agreement on the need to ensure the in situ conservation and availability of valuable genetic resources of wild species that are important for food security and nutrition. In order to be able to adopt adequate conservation measures a spatial assessment of their distribution and a sound analysis of the causes of and their sensitivity to threats is required. The ADA funded project “Threats to priority food tree species in Burkina Faso: Drivers of resource losses and mitigation measures” gave us the opportunity to develop a spati- ally explicit threat assessment methodology with focus on expert feedback, as there is no comprehensive and standardised approach available at the moment. Relevant threats were identified jointly with regional project partners from INERA and CNSF during meetings in Ouagadougou in 2012 and 2013 and by means of a case study on farmers’ perception. Once determined were the most important ones (overexploitation, overgrazing, fire, climate change, cotton production and mining) we identified openly accessible datasets suitable to represent the spatial patterns of threat intensities throughout the country. Now we needed to transform the threat intensities into potential impact over the target species distribution ranges. To do so the distribution and threat sensitivity of 16 food tree species were assessed by 17 local and international experts by means of an online feedback survey that was specifically developed for this project. These experts were asked to rate on a five point scale different distribution models and the sensitivity to threats. The survey was analysed applying a consensus method to identify the most consistent distribution model and threat specific sensitivity rating on a species by species basis. The potential impact of climate change was modeled using Global Circulation Models (GCM’s) deriving from the fifth assessment of the Intergovernmental Panel on Climate Change (IPCC5) in 2014. The results were then used to calculate and create individual and combined threat potential maps that enable the identification of areas in Burkina Faso where species are highly threatened. The spatial patterns of the threat levels provides evidence to prioritise food tree populations with relative urgency for undertaking conservation actions

Are we Dialogical or Sociomaterial in Our Written Corrective Feedback? A Reflection by Two Academic Writing Instructors

Despite the growing movement to embrace sociomaterial approaches to feedback practices (e.g. Gravett, 2020), dialogicity remains the prominent and dominant approach, especially in the teaching of introductory or compulsory writing courses at the tertiary level. To examine this in our own practice, we reflected on and compared our written corrective feedback (WCF) provided to our students. Based on our WCF practices, we contend that feedback practices may range from dialogic to sociomaterial. The former aims to ensure students’ learning of expected academic skills or objectives of a module, while the latter promotes students’ pursuit of content knowledge. These observations are noteworthy for other higher education instructors, whether subject experts or academic literacy instructors. In particular, we recommend that instructors need to carefully identify temporal and spatial contexts where either or both dialogic and sociomaterial feedback practices can be utilized to enhance students’ learning experiences

Global to local genetic diversity indicators of evolutionary potential in tree species within and outside forests

There is a general trend of biodiversity loss at global, regional, national and local levels. To monitor this trend, international policy processes have created a wealth of indicators over the last two decades. However, genetic diversity indicators are regrettably absent from comprehensive bio-monitoring schemes. Here, we provide a review and an assessment of the different attempts made to provide such indicators for tree genetic diversity from the global level down to the level of the management unit. So far, no generally accepted indicators have been provided as international standards, nor tested for their possible use in practice. We suggest that indicators for monitoring genetic diversity and dynamics should be based on ecological and demographic surrogates of adaptive diversity as well as genetic markers capable of identifying genetic erosion and gene flow. A comparison of past and present genecological distributions (patterns of genetic variation of key adaptive traits in the ecological space) of selected species is a realistic way of assessing the trend of intra-specific variation, and thus provides a state indicator of tree genetic diversity also able to reflect possible pressures threatening genetic diversity. Revealing benefits of genetic diversity related to ecosystem services is complex, but current trends in plantation performance offer the possibility of an indicator of benefit. Response indicators are generally much easier to define, because recognition and even quantification of, e.g., research, education, breeding, conservation, and regulation actions and programs are relatively straightforward. Only state indicators can reveal genetic patterns and processes, which are fundamental for maintaining genetic diversity. Indirect indicators of pressure, benefit, or response should therefore not be used independently of state indicators. A coherent set of indicators covering diversity–productivity–knowledge–management based on the genecological approach is proposed for application on appropriate groups of tree species in the wild and in cultivation worldwide. These indicators realistically reflect the state, trends and potentials of the world’s tree genetic resources to support sustainable growth. The state of the genetic diversity will be based on trends in population distributions and diversity patterns for selected species. The productivity of the genetic resource of trees in current use will reflect the possible potential of mobilizing the resource further. Trends in knowledge will underpin the potential capacity for development of the resource and current management of the genetic resource itself will reveal how well we are actually doing and where improvements are required

On-treatment function testing of platelets and long-term outcome of patients with peripheral arterial disease undergoing transluminal angioplasty

OBJECTIVE: To assess the clinical importance of on-treatment function testing of platelets in patients on aspirin after catheter-based vascular interventions. MATERIALS AND METHODS: In 109 patients with symptomatic peripheral arterial disease (PAD) of the lower limbs, platelet function testing (adenosine diphosphate-, collagen- and epinephrine-induced aggregation using light transmission aggregometry) was performed before and at multiple time points up to 1 year after a percutaneous angioplasty. Using univariate mixture models and Box-Cox transformation to ensure normally distributed individual variances, we investigated if an intraindividual variability exists and if it has a consequence for clinical outcome. RESULTS: Response to aspirin as measured by platelet aggregometry varies considerably over time in most patients. However, the intraindividual variance over time was not significantly correlated either with restenosis/reocclusion after 1 year or with adverse long-term outcome (occurrence of death for cardiovascular cause, stroke or myocardial infarction in up to 8 years follow-up). CONCLUSIONS: Response to aspirin does not seem to have a role in determining long-term outcome in patients with symptomatic PAD. The fact that testing of platelet function at only one time point has reduced significance may have implications for all clinical settings in which aspirin is used for the prevention of thrombo-embolic events

Entanglement Dynamics of Two Independent Cavity-Embedded Quantum Dots

We investigate the dynamical behavior of entanglement in a system made by two solid-state emitters, as two quantum dots, embedded in two separated micro-cavities. In these solid-state systems, in addition to the coupling with the cavity mode, the emitter is coupled to a continuum of leaky modes providing additional losses and it is also subject to a phonon-induced pure dephasing mechanism. We model this physical configuration as a multipartite system composed by two independent parts each containing a qubit embedded in a single-mode cavity, exposed to cavity losses, spontaneous emission and pure dephasing. We study the time evolution of entanglement of this multipartite open system finally applying this theoretical framework to the case of currently available solid-state quantum dots in micro-cavities.Comment: 10 pages, 4 figures, to appear in Topical Issue of Physica Scripta on proceedings of CEWQO 201