1,203 research outputs found
Greenhouse Gas Emissions Savings from Wind Power
Currently in Great Britain, estimates of the greenhouse gas (GHG) emissions savings that arise from wind power replacing other types of generation are approximated as the average emissions of electricity generation; however, this value is known to be incorrect - it assumes that wind power replaces all different forms of generation equally (which is not the case), and also ignores the detrimental effect that balancing the fluctuating output of wind power can have on the efficiency of conventional plant. There has been considerable debate as to whether the actual emissions displacement of wind power will be higher or lower than the average emissions value. The work presented in this poster provides robust values for this emissions displacement, through a detailed marginal analysis of historical operational data from the National Grid. It demonstrates that, between November 2008 and June 2013 the emissions displacement of wind power has been consistently higher than the published average annual emissions factor, despite the significant detrimental effect that wind power has on the efficiency (and thus emissions intensity) of coal and gas-fired plant
The composition of the protosolar disk and the formation conditions for comets
Conditions in the protosolar nebula have left their mark in the composition
of cometary volatiles, thought to be some of the most pristine material in the
solar system. Cometary compositions represent the end point of processing that
began in the parent molecular cloud core and continued through the collapse of
that core to form the protosun and the solar nebula, and finally during the
evolution of the solar nebula itself as the cometary bodies were accreting.
Disentangling the effects of the various epochs on the final composition of a
comet is complicated. But comets are not the only source of information about
the solar nebula. Protostellar disks around young stars similar to the protosun
provide a way of investigating the evolution of disks similar to the solar
nebula while they are in the process of evolving to form their own solar
systems. In this way we can learn about the physical and chemical conditions
under which comets formed, and about the types of dynamical processing that
shaped the solar system we see today.
This paper summarizes some recent contributions to our understanding of both
cometary volatiles and the composition, structure and evolution of protostellar
disks.Comment: To appear in Space Science Reviews. The final publication is
available at Springer via http://dx.doi.org/10.1007/s11214-015-0167-
Exploiting unexpected situations in the mathematics classroom
The professional development of mathematics teachers needs to support teachers in orchestrating the mathematics classroom in ways that enable them to respond flexibly and productively to the unexpected. When a situation arises in the classroom which is not connected in an obvious way to the mathematical learning intentions of the lesson, it can be challenging for the teacher to improvise so as to craft this situation into an opportunity for doing and learning mathematics. In this study, as teacher-researcher I maintained a record of unexpected situations as they arose in my own secondary mathematics classroom. Details are given of four unexpected situations which I found ways to exploit mathematically, and these are analysed to highlight factors which may enhance a mathematics teacher’s preparedness for dealing with the unexpected. The results of this study indicate that deviating from the intended lesson to exploit an unexpected situation in which students have shown some interest can lead them into enjoyable and worthwhile mathematical engagement
The war from both sides : how Dutch and German visitors experience an exhibit of Second World War stories
At the 75th anniversary of the end of the Second World War, questions arise if contemporary audiences still find historical accounts relevant. Fundamental to understanding the relevance of stories from the war is assessing their emotional impact on leisure participants from various social groups. We used the social identity theory framework to assess differences in emotional reactions of Dutch and German visitors to stories of the Second World War presented at a Dutch museum exhibit. Emotional reactions were measured using physiological signals of heart rate and heart rate variability as well as self-report. Emotions experienced were mixed and often, but not always, different between Dutch and German participants. Patterns in the physiological and self-report data differed. Many of the significant differences were generally consistent with a collective guilt account of German social identity, but the findings as a whole were more complex than could be predicted by existing social identity accounts. Specifically, participants did not simply categorize themselves with either national or human identities of characters based on what their respective stories emphasized. We conclude that stories of the Second World War are still relevant, but touch on audiences’ nationalities in a complex way, beyond simple historical categories
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SOFC chromite sintering and electrolyte/air-electrode interface reactions
Air sintering of chromites was investigated in La(Sr)CrO[sub 3], La(Ca)CrO[sub 3], and Y(Ca)CrO[sub 3]. Effects of alkaline earth dopant level and chromium enrichment/depletion on chromite sintered densities and microstructures are discussed. Ac impedance spectroscopy and dc polarization coupled with an unbonded interface cell were used to examine SOFC (solid oxide fuel cells) electrochemical reactions at solid-solid-gas interfaces, particularly for La[sub 1-x]Sr[sub x]MnO[sub 3]. 5 refs
The Real (Social) Experience of Monetary Policy
This paper takes a socio-economic approach to considering money in relation to real experience, focusing on the real effects of monetary policy. While most of the economics literature focuses on interest-rate setting as the core tool of monetary policy, we focus here instead on signalling by the central bank as a mechanism for influencing expectations and behaviour in conditions of uncertainty. This involves addressing the social-conventional expectations among different groups (a mechanism for dealing with uncertainty) applied to their particular ways of framing the real and financial sectors. Actual credit conditions faced by borrowers in turn are the outcome of the conventional view among banks as a result of their framing and the influence of central bank signalling. These relations between central banks, banks and the non-bank public in turn normally rest on long-established relations of trust. We consider the real effects of monetary policy in circumstances where trust has broken down
Unilateral, trifocal, diaphyseal fracture of the radius with ipsilateral mid-shaft ulna fracture in an adult: a case report
<p>Abstract</p> <p>Introduction</p> <p>To the best of our knowledge, a trifocal, diaphyseal fracture of the radius associated with ipsilateral mid-shaft fracture of the ulna in an adult has not been reported in the literature to date. The AO classification system does not include such a fracture configuration.</p> <p>Case presentation</p> <p>We report a case of trifocal, diaphyseal fracture of the radius with a mid-diaphyseal fracture of the ulna in a 53-year-old Caucasian, British, right-hand dominant woman involved in a head-on collision with another vehicle. The management of this rare fracture configuration is described and alternative treatment options discussed.</p> <p>Conclusions</p> <p>We describe an unusual, complex fracture, which with prompt surgical treatment resulted in a rapid, full and satisfactory functional recovery for our patient.</p
Using the Traditional Ex Vivo Whole Blood Model to Discriminate Bacteria by Their Inducible Host Responses
Whole blood models are rapid and versatile for determining immune responses to inflammatory and infectious stimuli, but they have not been used for bacterial discrimination. Staphylococcus aureus, S. epidermidis and Escherichia coli are the most common causes of invasive disease, and rapid testing strategies utilising host responses remain elusive. Currently, immune responses can only discriminate between bacterial ‘domains’ (fungi, bacteria and viruses), and very few studies can use immune responses to discriminate bacteria at the species and strain level. Here, whole blood was used to investigate the relationship between host responses and bacterial strains. Results confirmed unique temporal profiles for the 10 parameters studied: IL-6, MIP-1α, MIP-3α, IL-10, resistin, phagocytosis, S100A8, S100A8/A9, C5a and TF3. Pairwise analysis confirmed that IL-6, resistin, phagocytosis, C5a and S100A8/A9 could be used in a discrimination scheme to identify to the strain level. Linear discriminant analysis (LDA) confirmed that (i) IL-6, MIP-3α and TF3 could predict genera with 95% accuracy; (ii) IL-6, phagocytosis, resistin and TF3 could predict species at 90% accuracy and (iii) phagocytosis, S100A8 and IL-10 predicted strain at 40% accuracy. These data are important because they confirm the proof of concept that host biomarker panels could be used to identify bacterial pathogens
Single versus dual antiplatelet therapy following peripheral arterial endovascular intervention for chronic limb threatening ischaemia:retrospective cohort study
ObjectivesAntiplatelet therapy following peripheral arterial endovascular intervention lacks high quality evidence to guide practice. The aim of this study was to assess the effect of three months of dual antiplatelet therapy on amputation-free survival following peripheral arterial endovascular intervention in patients with chronic limb threatening ischemia.MethodsA retrospective review of symptomatic patients undergoing primary peripheral arterial endovascular intervention over a seven-year period was performed. The primary outcome measure was amputation-free survival. A sample size calculation based on previous cohort studies suggested that 629 limbs would be required to show a difference between single and dual therapy. Kaplan-Meier estimates and multivariate logistic regression analysis of recorded baseline characteristics was performed to determine predictors of amputation-free survival. Dual antiplatelet therapy was routinely given for 3 months.Results754 limbs were treated with primary angioplasty and/or stenting over a 7-year period, 508 of these for chronic limb threatening ischemia. There was no difference in unadjusted amputation-free survival between patients with chronic limb threatening ischaemia taking single vs. dual antiplatelet therapy (69% vs. 74% respectively Log rank Chi2 = 0.1, p = .72). After adjusting for confounders, at 1 year there was also no significant difference in amputation-free survival between patients taking single vs. dual antiplatelet therapy [OR 0.8, 95% CI 0.5-1.2, p = .3]. There was no difference in rates of major bleeding between single and dual antiplatelet therapy.ConclusionsThere was no clear evidence of reduced amputation-free survival in patients with chronic limb threatening ischemia undergoing peripheral arterial endovascular intervention being treated with dual antiplatelet therapy for 3 months. This is at odds with other retrospective case series and highlights the limitations in basing clinical practice on such data. There is a need for an adequately powered, independent randomised trial to definitively answer the question
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