Simulation of piston ring – cylinder liner lubrication considering layered fluid films

During the operation of hydrodynamically lubricated devices a fully formulated lubricant has the ability to form layers at the surfaces. A friction modifier’s task is to adjust the interaction between lubricant and the surface so that friction is lowered. An antiwear additive creates a protective layer on the surface and this definitely influence the performance of the lubricated device. To gain fundamental understanding, models that address the modified liquid – solid interaction due to the formation of layers, but also models that may be used to study the effects of layers already formed on the contacting surfaces are required. In this paper, two non-Newtonian lubricant rheology models that may be used to simulate reacted layers resembling those created by lubricant additives are adopted for the simulation of the piston ring – cylinder liner lubrication problem. The possibility of layer to layer interaction, which is likely to occur in the convex conjunction between the ring and the liner, is considered and this extends the models found in the literature. The effects induced by this type of layering are studied by using a modified Reynolds’ equation where the coefficients have been corrected with factors that accounts for the layer properties. This enables, effectively, studies of layers resembling those created by lubricant additives during the operation of the lubricated conjunction between a piston ring and a cylinder liner

Pedagogical Encounters in Music: Thinking with Hannah Arendt

This paper employs aspects of Hannah Arendt’s thought to explore different but interrelated questions that haunt contemporary music education. We see the importance of a return to Arendt now more than ever as we find ourselves, three authors in three different countries, trying to contribute to democratic music education practices and to researching the conceptual base of such practices, in countries where technocratic approaches to policy development prevail. More specifically in this article we address the following questions: how can we re-think the political and creative dimensions of music education pedagogies in the face of recent educational policy trends? How can we go beyond linearity in our everyday educational encounters? How can we create forms of music education practice and research that induce a continuous interplay between acting and thinking? We pursue these questions through reference to three specific forms of music education practice: research seminars for PhD-students and senior researchers, pre-service music teacher education, and teaching music improvisation. In the first part of the paper, Cecilia Ferm-Almqvist elaborates upon how Hannah Arendt’s thinking influences our teaching, taking an on-going research seminar in music education as an example of a common place. In the second part, Cathy Benedict writes of \u27meeting\u27 Arendt and coming to an awareness of how Arendt can help us interrogate practices we have come to assume as \u27the right ones\u27. Seeking to create together with her students an epistemological space of appearance she challenges common teaching strategies that seem to \u27wok\u27. Working within a teacher preparation program she comes to realize that students must also reflect on these moments so as to name what has occurred; thus they need to engage in acts of performative listening, setting aside their own desire and need to speak and be heard first. Finally, in the third part, Panagiotis (Panos) A. Kanellopoulos raises the complex issue of how we should respond to the current deliuge of entrepeneurial approaches to creativity, its use value, and its role in education. Based on the proposition that acts of musical improvisation belong to the realm of action, Kanellopoulos revisits Arendt\u27s notion of conservatism with the aim of outlining a possible way through which contemporary improvisation pedapgyg might be re-thought. Taken together these three sets of reflections serve to offer a framing of Arendt\u27s thinking for music educators in different contexts, showing how Arendt\u27s ideas might serve as a fertile for ground for thinking over our own teaching, our curricular decisions, and the choices we daily make over space and time that connect us through our distinctness

Hypospadias as a novel feature in spinal bulbar muscle atrophy

Spinal and bulbar muscle atrophy (SBMA) is an X-linked neuromuscular disorder caused by CAG repeat expansions in the androgen receptor (AR) gene. The SBMA phenotype consists of slowly progressive neuromuscular symptoms and undermasculinization features as the result of malfunction of the AR. The latter mainly includes gynecomastia and infertility. Hypospadias is also a feature of undermasculinization with an underdeveloped urethra and penis; it has not been described as part of the SBMA phenotype but has been suggested to be associated with a prolonged CAG repeat in the AR gene. This study includes the first epidemiologic description of the co-occurrence of hypospadias and SBMA in subjects and their male relatives in Swedish population-based health registers, as well as an additional clinical case. One boy with severe hypospadias was screened for mutations in the AR gene and was found to have 42 CAG repeats in it, which is in the full range of mutations causing SBMA later in life. We also detected a maximum of four cases displaying the combination of SBMA and hypospadias in our national register databases. This is the third case report with hypospadias in association with CAG repeat expansions in the AR gene in the full range known to cause SBMA later in life. Our findings suggest that hypospadias may be an under diagnosed feature of the SBMA phenotype and we propose that neurologists working with SBMA further investigate and report the true prevalence of hypospadias among patients with SBMA.Swedish Research Council, K2012-64X-14506-10-5Stockholm City CouncilFoundation Frimurare Barnhuset in StockholmSwedish Research Council through the Swedish Initiative for Research on Microdata in the Social And Medical Sciences (SIMSAM), 340-2013-5867Accepte

Increased mortality in patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency

Context: Reports on mortality in patients with congenital adrenal hyperplasia (CAH) are lacking. Objective: To study mortality and causes of death in CAH. Design, Setting and Participants: We studied patients with CAH (21-hydroxylase deficiency, n=588; CYP21A2 mutations known, >80%), and compared them with controls (n=58800). Data were derived through linkage of national population-based registers. Main Outcome Measures: Mortality and causes of death. Results: The mean age of death was 41.2±26.9 years in CAH patients and 47.7±27.7 years in controls (P<0.001). Among CAH patients 23 (3.9%) had deceased compared to 942 (1.6%) of controls. The hazard ratio (and 95% confidence interval) of death was 2.3(1.2-4.3) in CAH males and 3.5(2.0-6.0) in CAH females. Including only patients born 1952-2009, gave similar total results but only patients with salt-wasting or with unclear phenotype had an increased mortality. The causes of death in CAH patients were adrenal crisis (42%), cardiovascular (32%), cancer (16%), and suicide (10%). There were seven additional deaths in CAH individuals with incomplete or reused personal identification number that could not be analyzed using linkage of registers. Of the latter all except one were deceased before the introduction of neonatal screening in 1986 and most of them in the first weeks of life, probably in an adrenal crisis. Conclusions: CAH is a potentially lethal condition and was associated with excess mortality due to adrenal crisis. The salt-wasting phenotype seemed to have worse outcome also in children and adults due to adrenal crisis and not only before the introduction of neonatal screening.NonePublishe

Similar familial risk in multiple sclerosis subgroups Introduction

NonePublishe

Mapping the Margins: Navigating the Ecologies of Domestic Violence Service Provision

Work addressing the negative impacts of domestic violence on victim-survivors and service providers has slowly been contributing to the HCI discourse. However, work discussing the necessary, pre-emptive steps for researchers to enter these spaces sensitively and considerately, largely remains opaque. Heavily-politicised specialisms that are imbued with conflicting values and practices, such as domestic violence service delivery can be especially difficult to navigate. In this paper, we report on a mixed methods study consisting of interviews, a design dialogue and an ideation workshop with domestic violence service providers to explore the potential of an online service directory to support their work. Through this three-stage research process, we were able to characterise this unique service delivery landscape and identify tensions in services' access, understandings of technologies and working practices. Drawing from our findings, we discuss opportunities for researchers to work with and sustain complex information ecologies in sensitive settings

On the Two-Scale Modelling of Elastohydrodynamic Lubrication in Tilted-Pad Bearings

A two-scale method for modelling the Elastohydrodynamic Lubrication (EHL) of tilted-pad bearings is derived and a range of solutions are presented. The method is developed from previous publications and is based on the Heterogeneous Multiscale Methods (HMM). It facilitates, by means of homogenization, incorporating the effects of surface topography in the analysis of tilted-pad bearings. New to this article is the investigation of three-dimensional bearings, including the effects of both ideal and real surface topographies, micro-cavitation, and the metamodeling procedure used in coupling the problem scales. Solutions for smooth bearing surfaces, and under pure hydrodynamic operating conditions, obtained with the present two-scale EHL model, demonstrate equivalence to those obtained from well-established homogenization methods. Solutions obtained for elastohydrodynamic operating conditions, show a dependency of the solution to the pad thickness and load capacity of the bearing. More precisely, the response for the real surface topography was found to be stiffer in comparison to the ideal. Micro-scale results demonstrate periodicity of the flow and surface topography and this is consistent with the requirements of the HMM. The means of selecting micro-scale simulations based on intermediate macro-scale solutions, in the metamodeling approach, was developed for larger dimensionality and subsequent calibration. An analysis of the present metamodeling approach indicates improved performance in comparison to previous studies