303 research outputs found

    On the Linearization of the First and Second Painleve' Equations

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    We found Fuchs--Garnier pairs in 3X3 matrices for the first and second Painleve' equations which are linear in the spectral parameter. As an application of our pairs for the second Painleve' equation we use the generalized Laplace transform to derive an invertible integral transformation relating two its Fuchs--Garnier pairs in 2X2 matrices with different singularity structures, namely, the pair due to Jimbo and Miwa and the one found by Harnad, Tracy, and Widom. Together with the certain other transformations it allows us to relate all known 2X2 matrix Fuchs--Garnier pairs for the second Painleve' equation with the original Garnier pair.Comment: 17 pages, 2 figure

    The Generalized Dirichlet to Neumann map for the KdV equation on the half-line

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    For the two versions of the KdV equation on the positive half-line an initial-boundary value problem is well posed if one prescribes an initial condition plus either one boundary condition if qtq_{t} and qxxxq_{xxx} have the same sign (KdVI) or two boundary conditions if qtq_{t} and qxxxq_{xxx} have opposite sign (KdVII). Constructing the generalized Dirichlet to Neumann map for the above problems means characterizing the unknown boundary values in terms of the given initial and boundary conditions. For example, if {q(x,0),q(0,t)}\{q(x,0),q(0,t) \} and {q(x,0),q(0,t),qx(0,t)}\{q(x,0),q(0,t),q_{x}(0,t) \} are given for the KdVI and KdVII equations, respectively, then one must construct the unknown boundary values {qx(0,t),qxx(0,t)}\{q_{x}(0,t),q_{xx}(0,t) \} and {qxx(0,t)}\{q_{xx}(0,t) \}, respectively. We show that this can be achieved without solving for q(x,t)q(x,t) by analysing a certain ``global relation'' which couples the given initial and boundary conditions with the unknown boundary values, as well as with the function Φ(t)(t,k)\Phi^{(t)}(t,k), where Φ(t)\Phi^{(t)} satisifies the tt-part of the associated Lax pair evaluated at x=0x=0. Indeed, by employing a Gelfand--Levitan--Marchenko triangular representation for Φ(t)\Phi^{(t)}, the global relation can be solved \emph{explicitly} for the unknown boundary values in terms of the given initial and boundary conditions and the function Φ(t)\Phi^{(t)}. This yields the unknown boundary values in terms of a nonlinear Volterra integral equation.Comment: 21 pages, 3 figure

    In-depth analysis of chloride treatments for thin-film CdTe solar cells

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    CdTe thin-film solar cells are now the main industrially established alternative to silicon-based photovoltaics. These cells remain reliant on the so-called chloride activation step in order to achieve high conversion efficiencies. Here, by comparison of effective and ineffective chloride treatments, we show the main role of the chloride process to be the modification of grain boundaries through chlorine accumulation, which leads an increase in the carrier lifetime. It is also demonstrated that while improvements in fill factor and short circuit current may be achieved through use of the ineffective chlorides, or indeed simple air annealing, voltage improvement is linked directly to chlorine incorporation at the grain boundaries. This suggests that focus on improved or more controlled grain boundary treatments may provide a route to achieving higher cell voltages and thus efficiencies

    Mesophyll Resistance and Carboxylase Activity

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    Women’s experiences of wearing therapeutic footwear in three European countries

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    Background: Therapeutic footwear is recommended for those people with severe foot problems associated with rheumatoid arthritis (RA). However, it is known that many do not wear them. Although previous European studies have recommended service and footwear design improvements, it is not known if services have improved or if this footwear meets the personal needs of people with RA. As an earlier study found that this footwear has more impact on women than males, this study explores women’s experiences of the process of being provided with it and wearing it. No previous work has compared women’s experiences of this footwear in different countries, therefore this study aimed to explore the potential differences between the UK, the Netherlands and Spain. Method: Women with RA and experience of wearing therapeutic footwear were purposively recruited. Ten women with RA were interviewed in each of the three countries. An interpretive phenomenological approach (IPA) was adopted during data collection and analysis. Conversational style interviews were used to collect the data. Results: Six themes were identified: feet being visibly different because of RA; the referring practitioners’ approach to the patient; the dispensing practitioners’ approach to the patient; the footwear being visible as different to others; footwear influencing social participation; and the women’s wishes for improved footwear services. Despite their nationality, these women revealed that therapeutic footwear invokes emotions of sadness, shame and anger and that it is often the final and symbolic marker of the effects of RA on self perception and their changed lives. This results in severe restriction of important activities, particularly those involving social participation. However, where a patient focussed approach was used, particularly by the practitioners in Spain and the Netherlands, the acceptance of this footwear was much more evident and there was less wastage as a result of the footwear being prescribed and then not worn. In the UK, the women were more likely to passively accept the footwear with the only choice being to reject it once it had been provided. All the women were vocal about what would improve their experiences and this centred on the consultation with both the referring practitioner and the practitioner that provides the footwear. Conclusion: This unique study, carried out in three countries has revealed emotive and personal accounts of what it is like to have an item of clothing replaced with an ‘intervention’. The participant’s experience of their consultations with practitioners has revealed the tension between the practitioners’ requirements and the women’s ‘social’ needs. Practitioners need greater understanding of the social and emotional consequences of using therapeutic footwear as an intervention
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