761 research outputs found
A new high: Cannabis as a budding source of carbon-based materials for electrochemical power sources
Cannabis sativa L., a low-cost, fast-growing herbaceous plant, is seeing a resurgence in widespread cultivation as a result of new policies and product drive. Its biodegradable and environmentally benign nature coupled with its high specific surface area and three-dimensional hierarchal structure makes it an excellent candidate for use as a biomass-derived carbon material for electrochemical power sources. It is proposed that this âwonder cropâ could have an important role in the energy transition by providing high-functioning carbon-based materials for electrochemistry. In this article, all instances of C. sativa usage in batteries, fuel cells and supercapacitors are discussed with a focus on highlighting the high capacity, rate capability, capacitance, current density and half-wave potential that can be achieved with its utilisation in the field
Neutron studies of Na-ion battery materials
The relative vast abundance and more equitable global distribution of terrestrial sodium makes sodium-ion batteries (NIBs) potentially cheaper and more sustainable alternatives to commercial lithium-ion batteries (LIBs). However, the practical capacities and cycle lives of NIBs at present do not match those of LIBs and have therefore hindered their progress to commercialisation. The present drawback of NIB technology stems largely from the electrode materials and their associated Na+ion storage mechanisms. Increased understanding of the electrochemical storage mechanisms and kinetics is therefore vital for the development of current and novel materials to realise the commercial NIB. In contrast to x-ray techniques, the non-dependency of neutron scattering on the atomic number of elements (Z) can substantially increase the scattering contrast of small elements such as sodium and carbon, making neutron techniques powerful for the investigation of NIB electrode materials. Moreover, neutrons are far more penetrating which enables more complex sample environments including in situ and operando studies. Here, we introduce the theory of, and review the use of, neutron diffraction and quasi-elastic neutron scattering, to investigate the structural and dynamic properties of electrode and electrolyte materials for NIBs. To improve our understanding of the actual sodium storage mechanisms and identify intermediate stages during charge/discharge, ex situ, in situ, and operando neutron experiments are required. However, to date there are few studies where operando experiments are conducted during electrochemical cycling. This highlights an opportunity for research to elucidate the operating mechanisms within NIB materials that are under much debate at present
Neutron studies of Na-ion battery materials
The relative vast abundance and more equitable global distribution of terrestrial sodium makes sodium-ion batteries (NIBs) potentially cheaper and more sustainable alternatives to commercial lithium-ion batteries (LIBs). However, the practical capacities and cycle lives of NIBs at present do not match those of LIBs and have therefore hindered their progress to commercialisation. The present drawback of NIB technology stems largely from the electrode materials and their associated Na+ion storage mechanisms. Increased understanding of the electrochemical storage mechanisms and kinetics is therefore vital for the development of current and novel materials to realise the commercial NIB. In contrast to x-ray techniques, the non-dependency of neutron scattering on the atomic number of elements (Z) can substantially increase the scattering contrast of small elements such as sodium and carbon, making neutron techniques powerful for the investigation of NIB electrode materials. Moreover, neutrons are far more penetrating which enables more complex sample environments including in situ and operando studies. Here, we introduce the theory of, and review the use of, neutron diffraction and quasi-elastic neutron scattering, to investigate the structural and dynamic properties of electrode and electrolyte materials for NIBs. To improve our understanding of the actual sodium storage mechanisms and identify intermediate stages during charge/discharge, ex situ, in situ, and operando neutron experiments are required. However, to date there are few studies where operando experiments are conducted during electrochemical cycling. This highlights an opportunity for research to elucidate the operating mechanisms within NIB materials that are under much debate at present
FCNC Processes from D-brane Instantons
Low string scale models might be tested at the LHC directly by their Regge
resonances. For such models it is important to investigate the constraints of
Standard Model precision measurements on the string scale. It is shown that
highly suppressed FCNC processes like K0- bar K^0 oscillations or leptonic
decays of the D0-meson provide non-negligible lower bounds on both the
perturbatively and surprisingly also non-perturbatively induced string theory
couplings. We present both the D-brane instanton formalism to compute such
amplitudes and discuss various possible scenarios and their constraints on the
string scale for (softly broken) supersymmetric intersecting D-brane models.Comment: 28 pages, 13 figures, reference added, 1 typo corrected, style file
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What do general practitioners know about ADHD? Attitudes and knowledge among first-contact gatekeepers: systematic narrative review
Background: Attention Deficit Hyperactivity Disorder (ADHD) is a common childhood disorder with international prevalence estimates of 5 % in childhood, yet significant evidence exists that far fewer children receive ADHD services. In many countries, ADHD is assessed and diagnosed in specialist mental health or neuro-developmental paediatric clinics, to which referral by General (Family) Practitioners (GPs) is required. In such âgatekeeperâ settings, where GPs act as a filter to diagnosis and treatment, GPs may either not recognise potential ADHD cases, or may be reluctant to refer. This study systematically reviews the literature regarding GPsâ views of ADHD in such settings.
Methods: A search of nine major databases was conducted, with wide search parameters; 3776 records were initially retrieved. Studies were included if they were from settings where GPs are typically gatekeepers to ADHD services; if they addressed GPsâ ADHD attitudes and knowledge; if methods were clearly described; and if results for GPs were reported separately from those of other health professionals.
Results: Few studies specifically addressed GP attitudes to ADHD. Only 11 papers (10 studies), spanning 2000â2010, met inclusion criteria, predominantly from the UK, Europe and Australia. As studies varied methodologically, findings are reported as a thematic narrative, under the following themes: Recognition rate; ADHD controversy (medicalisation, stigma, labelling); Causes of ADHD; GPs and ADHD diagnosis; GPs and ADHD treatment; GP ADHD training and sources of information; and Age, sex differences in knowledge and attitudes.
Conclusions: Across times and settings, GPs practising in first-contact gatekeeper settings had mixed and often unhelpful attitudes regarding the validity of ADHD as a construct, the role of medication and how parenting contributed to presentation. A paucity of training was identified, alongside a reluctance of GPs to become involved in shared care practice. If access to services is to be improved for possible ADHD cases, there needs to be a focused and collaborative approach to training
Dissolved iron in the Bermuda region of the subtropical North Atlantic Ocean: Seasonal dynamics, mesoscale variability, and physicochemical speciation
18 months embargo minus one day to account for leap year
Adapting a Program to Inform African American and Hispanic American Women About Cancer Clinical Trials
The dearth of evidence-based clinical trial education programs may contribute to the underrepresentation of African American and Hispanic American women in cancer research studies. This study used focus group-derived data from 80 women distributed among eight Spanish- and English-language focus groups. These data guided the researchersâ adaptation and refinement of the National Cancer Instituteâs various clinical trials education programs into a program that was specifically focused on meeting the information needs of minority women and addressing the barriers to study participation that they perceived. A âsisterhoodâ theme was adopted and woven throughout the presentation
A prospective study of chemotherapy-induced febrile neutropenia in the South West London Cancer Network. Interpretation of study results in light of NCAG/NCEPOD findings
BACKGROUND: Chemotherapy-induced febrile neutropenia is a medical emergency complicating the treatment of many cancer patients. It is associated with considerable morbidity and mortality, as well as impacting on healthcare resources. METHODS: A prospective study of all cases of chemotherapy-induced febrile neutropenia in the South West London Cancer Network was conducted over a 4-month period. Factors including demographics, treatment history, management of febrile neutropenia and outcome were recorded. RESULTS AND CONCLUSION: Our results reflect those of the recent National Chemotherapy Advisory Group (NCEPOD, 2008)/National Confidential Enquiry into Patient Outcomes and Death reports (NCAG, 2009) and highlight the need for network-wide c inical care pathways to improve outcomes in this area, British Journal of Cancer (2011) 104, 407-412. doi:10.1038/sj.bjc.6606059 www.bjcancer.com Published online 21 December 2010 (C) 2011 Cancer Research U
Identifying Trends in Masterplanning: A Typological Classification System
This document is the Accepted Manuscript version of the following article: Robert Adam, and Claire Jamieson, âIdentifying trends in masterplanning: A typological classification systemâ, URBAN DESIGN International, Vol. 19 (4): 274-290, December 2014. The final publication is available at Springer via https://doi.org/10.1057/udi.2013.24.This article reports research carried out to develop a new typological method for the analysis of masterplans. This quantitative method of analysis can be used to produce comparative data that will help in the comparison of urban design typologies and their development over time. This article sets out the research to date, describing how the initial aims have developed from simple analysis to the creation of an analytical tool with wide applications. Comprising a detailed taxonomy of urban design features gathered from a wide database of recent and emerging masterplans, the system provides opportunities for further study such as trends, qualitative comparison against quantitative measurement, and comparison of aims and outcomes. This article will describe the methodology and process of research, while elaborating on the potential of the tool.Peer reviewedFinal Accepted Versio
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