Experimental Observation of Sphere Symmetric Isolated Single Droplet Combustion in a Converging Channel

Spherically symmetric isolated single droplet combustion has been observed mainly in microgravity conditions. This study sought to determine if spherically symmetric combustion can be produced in a lab-scale experiment using flow acceleration to counteract the effects of buoyancy. The experiment was conducted in a converging channel that decreased in width along its length to accelerate the flow and limit the formation of a boundary layer. The rate at which the area decreased was governed by the initial velocity condition set at the channel inlet. The droplets were generated using a piezoelectric actuator which forced fuel out of an injector with a very narrow inner diameter. A thin metal disk at the top of the main fuel reservoir allowed the piezoelectric to directly influence the pressure of the fluid in the system. The flowrate of fuel through the system was held constant by a syringe pump. The diameter of droplets produced was approximately 0.5 – 0.6 mm and the fuels used were n-Heptane and ethanol. It was found that the initial velocity at the inlet of the converging channel was 1 m/s. This velocity was used to define the curvature needed to observe sphere symmetric flames. A transition from laminar flow to turbulent flow within the converging channel due to the boundary layer growth was found. The droplet diameter and flame diameter were observed at various points along the length of the channel. The droplet diameter was determined using backlight imaging and a Photron Fastcam SA-Z highspeed camera. To observe the flame diameter, an Andor iStar intensified complementary metal oxide semiconductor (ICMOS) camera was used. From this study, it was concluded that spherically symmetric flames can be created and observed under normal gravitational conditions utilizing accelerated fluid flow through a converging channel. The nature of this apparatus allows for further investigation into spherically symmetric isolated droplet combustion utilizing laser diagnostic techniques and nuclear magnetic resonance (NMR) imaging to analyze the composition of partially combusted samples. This will allow further study into the effects of preferential vaporization on multi-component mixtures

Perceptions Of School By Two Teenage Boys With Asperger Syndrome And Their Mothers: A Qualitative Study

This qualitative study aimed to develop an understanding of the challenges faced by teenage boys with Asperger syndrome and their mothers. A case study approach was used to collect data from two 13-year-old boys who have Asperger syndrome and their mothers in Queensland, Australia. Data were collected through the use of semi¬structured interviews. The words of the boys and their mothers provide a valuable insight into the personal experiences and feelings of the par¬ticipants. An inductive approach to data analysis identified four themes: (1) developmental differences; (2) problems associated with the general characteristics of Asperger syndrome (i.e. communication and social difficulties, restricted range of interests, a need for routine); (3) stress; and (4) 'masquerading'. The first three themes relate strongly to the current literature, but the emergence of masquerading is of particular interest in developing a fuller understanding of the experiences of individuals with Asperger syndrome at school

Managing the Tensions at the Intersection of the Triple Bottom Line: A Paradox Theory Approach to Sustainability Management

Corporate sustainability management encompasses multiple dimensions: environmental, social, and economic. Companies are increasingly evaluated within the public sphere, and within their own organizations, according to the degree to which they are perceived to simultaneously promote this nexus of virtues. This article seeks to explore the tensions frequently faced by organizations that strive to manage these dimensions and the role of public policy in that pursuit. A multiple–case study approach is utilized in which the authors selected case organizations according to whether they were attempting to manage the three dimensions of sustainability. The authors utilize paradox theory and a typology provided by previous research to understand the nature of the tensions that emerge in the selected case study organizations. They extend this previous work by examining the role of public policy in providing the situational conditions to make these paradoxical tensions salient, and they examine organizational responses to these conditions. Directions for firms, policy makers, and future researchers are provided on the basis of this study’s findings

Managing the Tensions at the Intersection of the Triple Bottom Line: A Paradox Theory Approach to Sustainability Management

Corporate sustainability management encompasses multiple dimensions: environmental, social, and economic. Companies are increasingly evaluated within the public sphere, and within their own organizations, according to the degree to which they are perceived to simultaneously promote this nexus of virtues. This article seeks to explore the tensions frequently faced by organizations that strive to manage these dimensions and the role of public policy in that pursuit. A multiple–case study approach is utilized in which the authors selected case organizations according to whether they were attempting to manage the three dimensions of sustainability. The authors utilize paradox theory and a typology provided by previous research to understand the nature of the tensions that emerge in the selected case study organizations. They extend this previous work by examining the role of public policy in providing the situational conditions to make these paradoxical tensions salient, and they examine organizational responses to these conditions. Directions for firms, policy makers, and future researchers are provided on the basis of this study’s findings

Cricket, migration and diasporic communities

Ever since different communities began processes of global migration, sport has been an integral feature in how we conceptualise and experience the notion of being part of a diaspora. Sport provides diasporic communities with a powerful means for creating transnational ties, but also shapes ideas of their ethnic and racial identities. In spite of this, theories of diaspora have been applied sparingly to sporting discourses. Due mainly to its central role in spreading dominant white racial narratives within the British Empire, and the various ways different ethnic groups have ‘played’ with the meanings and associations of the sport in the (post-)colonial period, cricket is an interesting focus for academic research. Despite W.G. Grace’s claim that cricket advances civilisation by promoting a common bond, binding together peoples of vastly different backgrounds, to this day cricket operates strict symbolic boundaries; defining those who do, and equally, do not belong. C.L.R. James’ now famous metaphor of looking ‘beyond the boundary’ captures the belief that, to fully understand the significance of cricket, and the sport’s roles in changing and shaping society, one must consider the wider social and political contexts within which the game is played. The collection of papers in this special issue does just that. Cricket acts as the point of departure in each, but the way in which ideas of power, representation and inequality are ‘played out’ is unique in each

Recovery: What does this mean to patients with low back pain?

Copyright © 2009, American College of Rheumatology. This article is freely available through the publisher’s link below.Objective - To explore patients' perceptions of recovery from low back pain, about which little is known. Methods - A qualitative study was conducted in which 36 participants, either recovered or unrecovered from low back pain, participated in focus groups. Interviews were audiorecorded and transcribed verbatim. Framework analysis was used to identify emergent themes and domains of recovery. Results - Patients' views of recovery encompassed a range of factors that can be broadly classified into the domains of symptom attenuation, improved capacity to perform a broad scope of self-defined functional activities, and achievement of an acceptable quality of life. An interactive model is proposed to describe the relationships between these domains, cognitive appraisal of the pain experience, and self-rated recovery. Pain attenuation alone was not a reliable indicator of recovery. Conclusion - The construct of recovery for typical back pain patients seeking primary care is more complex than previously recognized and is a highly individual construct, determined by appraisal of the impact of symptoms on daily functional activities as well as quality of life factors. These findings will be valuable for reassessing how to optimize measures of recovery from low back pain by addressing the spectrum of factors patients consider meaningful

Magneto-Transport Properties of Doped RuSr2_2GdCu2_2O8_8

RuSr$_2$GdCu$_2$O$_8$, in which magnetic order and superconductivity coexist with $T_{Magnetic}$$\gg$$T_c$, is a complex material which poses new and important questions to our understanding of the interplay between magnetic and superconducting (SC) order. Resistivity, Hall effect and thermopower measurements on sintered ceramic RuSr$_2$GdCu$_2$O$_8$ are presented, together with results on a broad range of substituted analogues. The Hall effect and thermopower both show anomalous decreases below $T_{Magnetic}$ which may be explained within a simple two-band model by a transition from localized to more itinerant behavior in the RuO$_2$ layer at $T_{Magnetic}$.Comment: 10 pages, 7 figures, submitted to Phys. Rev. B., correspondence to [email protected]