735 research outputs found
First-Principles Calculation of Electric Field Gradients and Hyperfine Couplings in YBa2Cu3O7
The local electronic structure of YBa2Cu3O7 has been calculated using
first-principles cluster methods. Several clusters embedded in an appropriate
background potential have been investigated. The electric field gradients at
the copper and oxygen sites are determined and compared to previous theoretical
calculations and experiments. Spin polarized calculations with different spin
multiplicities have enabled a detailed study of the spin density distribution
to be made and a simultaneous determination of magnetic hyperfine coupling
parameters. The contributions from on-site and transferred hyperfine fields
have been disentangled with the conclusion that the transferred spin densities
essentially are due to nearest neighbour copper ions only with marginal
influence of ions further away. This implies that the variant temperature
dependencies of the planar copper and oxygen NMR spin-lattice relaxation rates
are only compatible with commensurate antiferromagnetic correlations. The
theoretical hyperfine parameters are compared with those derived from
experimental data.Comment: 14 pages, 12 figures, accepted to appear in EPJ
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Interdisciplinary educational approaches to clothing longevity
How do we encourage and enable interdisciplinary systems thinking approaches to sustainable fashion design and business education? In preparation for a workshop at the 2017 PLATE conference, this paper introduces the context of a toolkit – The Clothing Durability Dozen (Cooper at al, 2016b) – aimed at enabling students to collaborate and learn about clothing longevity across disciplines and creating a better understanding of the roles that different departments can play in placing sustainable design strategies at the heart of the clothing industry. In line with education for sustainable development (ESD) principles, objectives include stimulating learning and promote core competencies, such as critical and systemic thinking, collaborative decision-making, and taking responsibility for present and future generations. In the workshop, participants will trial and contribute to the development of the toolkit and any necessary supporting material, the final version of which will be available for use as an educational tool
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New product development and testing strategies for clothing longevity
Many garments have short life-spans, contributing to excessive carbon emissions, water consumption and waste. This paper reports on a research project which aimed to identify expectations of clothing longevity, examine the NPD process within the supply chain and identify opportunities for change, evaluate the potential for innovative technologies and improved product testing, and explore business practices aimed at more sustainable approaches to NPD. The paper provides an overview of the two-year project, presenting key findings from data collection that included interviews with 31 industry practitioners, three consumer focus groups, three industry and consumer round tables, an expert workshop, and four pilot actions undertaken with UK clothing retailers to evaluate key issues. The research identified and explored themes relating to NPD that could enable increased garment lifetimes, which were consolidated into six areas: the adoption of advanced textile processes and finishing techniques, action to overcome constraints on appropriate product testing, the potential for retailers to influence consumer behaviour, a loss of technical expertise and lack of multi-disciplinary collaboration, failure to embed good practice early in the NPD process, and evidence to encourage retailers and brands to adopt new business models. Industry and government policy recommendations were proposed to improve knowledge-sharing, strengthen the business case and influence consumer behaviour, while further research may be needed on the adoption of new garment and textile technologies, the business case and the global context of the clothing industry
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Clothing Longevity Protocol: final
The Clothing Longevity Protocol offers guidelines for good practice in order to aid moves towards garments that will last longer and thus to help protect brand value, screen out garments which fail prematurely and reduce the environmental impact of the clothing sector
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Creativity at work and sustainable product development: practitioner perspectives from the clothing industry
This chapter addresses creativity in the context of product development within the creative industries, incorporating an example from the clothing industry. In relation to creativity and product development, designers are supported by many other actors, such as technologists, engineers and buyers, who are also creative in their own right. We begin by exploring creativity at work, which we consider to encompass idea generation comprising creative problem-solving, moving beyond product ideas to service and commercial concepts. Product (or service) development, improvement and practical process adaptation are amongst the various tangible aspects of creativity which can be managed, whereas other aspects of creativity such as creative thought processes are less tangible and consequently less manageable. In the clothing sector the temporal, financial and technical parameters of creativity at work are set for designers by other functions within their own organisation and from their clients and suppliers, subject to conflicting commercial demands. Sustainable design through clothing longevity appears at odds with the priorities of the prevailing ‘fast fashion’ business model. Challenging issues such as sustainability and longevity require innovative solutions and the creative thought processes used by designers could be central to improving sustainability within the fashion industry.
To demonstrate how creativity at work can operate in practice, we present a case that investigates the implementation of creative idea generation, within the boundaries of sustainable product development in the context of the clothing industry. This research aimed to reveal barriers, enablers, knowledge, processes, infrastructure and consumer views that support wider adoption of practices that can facilitate product longevity. We adopted a mixed methodology, including semi-structured interviews and round-table discussions with garment industry stakeholders from a range of roles in fashion retail, the supply chain and academia, to debate specific themes concerned with supplying clothing that lasts for longer. Subsequently, pilot interventions highlighted the factors that, in practice, promote and inhibit improved clothing longevity
Integration of professional judgement and decision-making in high-level adventure sports coaching practice
This study examined the integration of professional judgement and decision-making processes in adventure sports coaching. The study utilised a thematic analysis approach to investigate the decision-making practices of a sample of high-level adventure sports coaches over a series of sessions. Results revealed that, in order to make judgements and decisions in practice, expert coaches employ a range of practical and pedagogic management strategies to create and opportunistically use time for decision-making. These approaches include span of control and time management strategies to facilitate the decision-making process regarding risk management, venue selection, aims, objectives, session content, and differentiation of the coaching process. The implication for coaches, coach education, and accreditation is the recognition and training of the approaches that“create time” for the judgements in practice, namely“creating space to think”. The paper concludes by offering a template for a more expertise-focused progression in adventure sports coachin
High-dose vitamin D(3) during intensive-phase antimicrobial treatment of pulmonary tuberculosis: a double-blind randomised controlled trial.
BACKGROUND: Vitamin D was used to treat tuberculosis in the pre-antibiotic era, and its metabolites induce antimycobacterial immunity in vitro. Clinical trials investigating the effect of adjunctive vitamin D on sputum culture conversion are absent. METHODS: We undertook a multicentre randomised controlled trial of adjunctive vitamin D in adults with sputum smear-positive pulmonary tuberculosis in London, UK. 146 patients were allocated to receive 2·5 mg vitamin D(3) or placebo at baseline and 14, 28, and 42 days after starting standard tuberculosis treatment. The primary endpoint was time from initiation of antimicrobial treatment to sputum culture conversion. Patients were genotyped for TaqI and FokI polymorphisms of the vitamin D receptor, and interaction analyses were done to assess the influence of the vitamin D receptor genotype on response to vitamin D(3). This trial is registered with ClinicalTrials.gov number NCT00419068. FINDINGS: 126 patients were included in the primary efficacy analysis (62 assigned to intervention, 64 assigned to placebo). Median time to sputum culture conversion was 36·0 days in the intervention group and 43·5 days in the placebo group (adjusted hazard ratio 1·39, 95% CI 0·90-2·16; p=0.14). TaqI genotype modified the effect of vitamin D supplementation on time to sputum culture conversion (p(interaction)=0·03), with enhanced response seen only in patients with the tt genotype (8·09, 95% CI 1·36-48·01; p=0·02). FokI genotype did not modify the effect of vitamin D supplementation (p(interaction)=0·85). Mean serum 25-hydroxyvitamin D concentration at 56 days was 101·4 nmol/L in the intervention group and 22·8 nmol/L in the placebo group (95% CI for difference 68·6-88·2; p<0·0001). INTERPRETATION: Administration of four doses of 2·5 mg vitamin D(3) increased serum 25-hydroxyvitamin D concentrations in patients receiving intensive-phase treatment for pulmonary tuberculosis. Vitamin D did not significantly affect time to sputum culture conversion in the whole study population, but it did significantly hasten sputum culture conversion in participants with the tt genotype of the TaqI vitamin D receptor polymorphism. FUNDING: British Lung Foundation
General-purpose methods for simulating survival data for expected value of sample information calculations
Background: Expected value of sample information (EVSI) quantifies the expected value to a decision maker of reducing uncertainty by collecting additional data. EVSI calculations require simulating plausible datasets, typically achieved by evaluating quantile functions at random uniform numbers using standard inverse transform sampling (ITS). This is straightforward when closed-form expressions for the quantile function are available, such as for standard parametric survival models, but these are often unavailable when assuming treatment effect waning and for flexible survival models. In these circumstances, the standard ITS method could be implemented by numerically evaluating the quantile functions at each iteration in a probabilistic analysis, but this greatly increases the computational burden. Thus, our study
aims to develop general-purpose methods that standardize and reduce the computational burden of the EVSI data-simulation step for survival data. Methods: We developed a discrete sampling method and an interpolated ITS method for simulating survival data from a probabilistic sample of survival probabilities over discrete time units. We compared the general-purpose and standard ITS methods using an illustrative partitioned survival model with and without adjustment for treatment effect waning. Results: The discrete sampling and interpolated ITS methods agree closely with the standard ITS method, with the added benefit of a greatly reduced computational cost in the scenario with adjustment for treatment effect waning. Conclusions: We present general-purpose methods for simulating survival data from a
probabilistic sample of survival probabilities that greatly reduce the computational burden of the EVSI data-simulation step when we assume treatment effect waning or use flexible survival models. The implementation of our data-simulation methods is identical across all possible survival models and can easily be automated from standard probabilistic decision analyses
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