Physical Properties of White-Light Sources in the 2011 Feb 15 Solar Flare

White light flares (WLFs) are observational rarities, making them understudied events. However, optical emission is a significant contribution to flare energy budgets and the emission mechanisms responsible could have important implications for flare models. Using Hinode SOT optical continuum data taken in broadband red, green and blue filters, we investigate white-light emission from the X2.2 flare SOL2011-02-15T01:56:00. We develop a technique to robustly identify enhanced flare pixels and, using a knowledge of the RGB filter transmissions, determined the source color temperature and effective temperature. We investigated two idealized models of WL emission - an optically thick photospheric source, and an optically thin chromospheric slab. Under the optically thick assumption, the color temperature and effective temperature of flare sources in sunspot umbra and penumbra were determined as a function of time and position. Values in the range of 5000-6000K were found, corresponding to a blackbody temperature increase of a few hundred kelvin. The power emitted in the optical was estimated at $\sim 10^{26}$ergs s$^{-1}$. In some of the white-light sources the color and blackbody temperatures are the same within uncertainties, consistent with a blackbody emitter. In other regions this is not the case, suggesting that some other continuum emission process is contributing. An optically thin slab model producing hydrogen recombination radiation is also discussed as a potential source of WL emission; it requires temperatures in the range 5,500 - 25,000K, and total energies of $\sim 10^{27}$ergs s$^{-1}$.Comment: Accepted for publication in the Astrophysical Journal, 15 pages, 15 figure

Promoting Group Justice: Fiscal Policies in Post-Conflict Countries

In the aftermath of violent conflict, governments have an opportunity to address fundamental inequalities between internal groups. As taxation and expenditure policies are developed to rebuild a functional domestic economy and infrastructure, policies can be designed to lessen divisions and promote equity.The authors assert that good data about the status quo on inequality in a country is the first step to addressing it through policy. They then discuss some options for formulating a tax code that addresses distributional issues and increases progressivity. Expenditure planning can also be designed to help create equity in income and non-income resources, such as public services, employment, health and education. The role of aid donors is discussed, particularly as a source of successful strategies gleaned from other post-conflict countries.This study is part of a series on Public Finance in Post-Conflict Environments, published jointly by PERI and New York University's Center on International Cooperation.inequality; horizontal inequality; post-conflict economies; fiscal policies; taxation incidence; expenditure incidence

The Implications of Horizontal Inequality for Aid

This paper argues that the reduction of horizontal inequalities (HIs) or inequalities between culturally defined groups should inform aid policy in heterogeneous countries with severe HIs. It shows how this would change aid allocation across countries, leading to more aid to heterogeneous countries relative to homogeneous ones, the opposite of the existing bias in aid distribution. It explores how adopting an HI approach would affect the use of particular aid instruments, arguing that different instruments are appropriate according to the attitude and capacity of the government in relation to correcting HIs. Drawing on case studies of Ghana and Nepal it argues that at present there is neglect of HI considerations in aid policy, which can be particularly damaging where aid forms a large part of government resources.aid, horizontal inequality, social exclusion, Nepal, Ghana

Working Towards Green Tourism Accreditation at Dawyck Botanic Garden

Dawyck Botanic Garden was awarded a Silver accreditation in the Green Tourism Business Scheme in December 2010. The award was the result of a sustained focus to pursue an industry award as a measure of Dawyck’s achievements in sound environmental management. The award followed the construction of a new Visitor Centre in 2008 and also built upon green initiatives already achieved by staff. This case study follows the stages of the process up to the point of the award being made

A 50 year old with a rapid neuropsychiatric deterioration and choreaform movements

A 50-year-old man presented acutely to the hospital with behavioural disturbance, choreiform movements and profound nihilistic delusions. He reported recent drug and alcohol abuse, and also apparent involvement in several recent criminal activities, for which he felt he should be punished. He arrived alone at the hospital after a concerned neighbour had called an ambulance. His initial level of agitation prevented formal cognitive testing. However, he was alert, verbally responsive and could obey commands. He was afebrile with normal observations and normal plasma glucose. Although his examination was challenging, the only abnormal neurological findings were bilateral choreiform upper limb movements

Manipulation of carbon media, temperature and hydraulic efficiency to increase nitrate removal rate in denitrification beds

The accumulation of reactive nitrogen (Nr) in terrestrial and aquatic environments is a global environmental issue that causes or contributes to climate change, stratospheric ozone depletion, and deterioration of coastal and terrestrial waters. Point source discharges of Nr from municipal and septic treatment systems, agricultural tile drainage, and industrial discharges contribute to these issues. Practical, low-cost methods are needed to reduce the Nr load into the environment from small-volume point source discharges. Denitrification beds are one such method. Improving the nitrate removal rate of denitrification beds will lead to reduced bed volumes, lower construction costs that likely facilitate greater uptake of the technology and reduced accumulation of Nr in the environment. The main objective of this thesis was to test a number of approaches that might increase the rate of nitrate removal rate in a denitrification bed under non-nitrate limiting conditions, including: manipulation of carbon source, temperature and hydraulic flow. To date, operational denitrification beds have used wood media as the carbon source which sustains nitrate removal rates of between 2–10 g N m-3 of media d-1 and relatively high permeability. While previous laboratory experiments have investigated the potential of alternative carbon sources, these studies were typically of short duration and small scale and did not necessarily provide reliable information for denitrification bed design purposes. To address this issue, nitrate removal, hydraulic and nutrient leaching characteristics of nine different carbon substrates were compared in 0.2 m3 barrels, at 14oC and 23.5oC over a 23 month period. The relationship between hydraulic efficiency and nitrate removal of the different media was also investigated. Findings from the barrel trial were field tested in pilot scale (2.9 m3) denitrification beds receiving municipal effluent dosed with KNO3, over a 15 month period. The pilot scale trial tested whether nitrate removal could be improved by using an alternative carbon media (maize cobs) and increasing bed temperature through passive solar heating. The influence of bed flow regime (horizontal-point, horizontal-diffuse, downflow and upflow) on hydraulic efficiency and nitrate removal was also investigated. This thesis demonstrated that more labile carbon sources, such as maize cobs, had significantly higher nitrate removal rates (15.0 to 21.8 g N m-3 d-1) than wood media (3.0 to 4.9 g N m-3 d-1) over the duration of the barrel trial. Nitrate removal rates increased with increasing temperature with mean Q10 of 1.6 for all media. The hydraulic efficiency of fragmented wood media decreased with increasing grain-size. However, nitrate removal rate was not dependent on hydraulic efficiency of the media, which was attributed to the significant secondary porosity of the media allowing denitrification to occur both on the surface and within the media particle. In the pilot scale trial, bed temperature increased by 3.4oC due to passive solar heating, but did not cause a measureable increase in nitrate removal rate due to variability in removal rates and possibly low temperature responsiveness of maize cobs for removing nitrate. Flow regime affected the hydraulic efficiency of denitrification beds and nitrate removal rates were lower in flow regimes with poor hydraulic efficiency. This was attributed to short-circuit flow reducing the bed volume that contributed to nitrate removal. The results indicate that a four-fold reduction in denitrification bed size could potentially be achieved by using maize cobs as the carbon substrate, as opposed to wood fragments, and increasing bed temperature by incorporating passive solar heating techniques. The findings of this thesis indicate that future research on improving the nitrate removal rate of denitrification beds under non-nitrate limiting conditions should focus on carbon substrates, increasing bed temperature, and hydraulic design of beds rather than on hydraulic efficiency of media. For example, research on coupling improved solar heating design with an appropriate inlet/outlet structure and location

Graph Algorithms and Complexity Aspects on Special Graph Classes

Graphs are a very flexible tool within mathematics, as such, numerous problems can be solved by formulating them as an instance of a graph. As a result, however, some of the structures found in real world problems may be lost in a more general graph. An example of this is the 4-Colouring problem which, as a graph problem, is NP-complete. However, when a map is converted into a graph, we observe that this graph has structural properties, namely being (K_5, K_{3,3})-minor-free which can be exploited and as such there exist algorithms which can find 4-colourings of maps in polynomial time. This thesis looks at problems which are NP-complete in general and determines the complexity of the problem when various restrictions are placed on the input, both for the purpose of finding tractable solutions for inputs which have certain structures, and to increase our understanding of the point at which a problem becomes NP-complete. This thesis looks at four problems over four chapters, the first being Parallel Knock-Out. This chapter will show that Parallel Knock-Out can be solved in O(n+m) time on P_4-free graphs, also known as cographs, however, remains hard on split graphs, a subclass of P_5-free graphs. From this a dichotomy is shown on $P_k$-free graphs for any fixed integer $k$. The second chapter looks at Minimal Disconnected Cut. Along with some smaller results, the main result in this chapter is another dichotomy theorem which states that Minimal Disconnected Cut is polynomial time solvable for 3-connected planar graphs but NP-hard for 2-connected planar graphs. The third chapter looks at Square Root. Whilst a number of results were found, the work in this thesis focuses on the Square Root problem when restricted to some classes of graphs with low clique number. The final chapter looks at Surjective H-Colouring. This chapter shows that Surjective H-Colouring is NP-complete, for any fixed, non-loop connected graph H with two reflexive vertices and for any fixed graph H’ which can be obtained from H by replacing vertices with true twins. This result enabled us to determine the complexity of Surjective H-Colouring on all fixed graphs H of size at most 4

The Design of Toys for Autistic Children

A commendable feature of craft students' projects at B.Ed. degree level is the opportunity made available to tackle needy problems too often neglected by the professional designer and manufacturer - a neglect not necessarily caused by a lack of sympathy but rather by the harsh realities of the business world where, in the final analysis, any venture must be financially viable. This often prec!udes the manufacturer of small numbers of specialist goods for isolated groups of individuals which would not provide the cost effectiveness of mass production or, indeed, where insufficient finance is available for purchase