134 resultados para Fluid Inclusion
Resumo:
In a global context of an emphasis on identity politics and a ‘cultural turn’ in social analysis, deep concern has been expressed about multiethnic Britain becoming a broken society with many ‘sleepwalking’ into segregation and separatism. Given the close correspondence between areas of acute ethnic segregation and those of multiple deprivation, intercommunal tensions have included disputes about the equitable allocation of scarce urban resources across ethnicity. This creates the possibility that urban programmes may inadvertently accentuate intercommunal tension and confound efforts to synchronise cohesion and inclusion agendas. Following recent debates about the implications of increased diversity, influenced by arguments that multiculturalism has encouraged ‘parallel lives’, an emergent policy framework emphasises more proactive integration to promote ‘common belonging’. Criticism of this agenda includes its confusion between community and social cohesion, and its disproportionate focus on cultural aspects such as identity formation and recognition, relative to structural issues of income and class. In exploring this contested terrain in Britain, the article suggests that the longer-term debate about segregation, deprivation and community differentials in Northern Ireland can offer useful insight for Britain’s policy discourse.
Resumo:
The language of EU rural development policy appears more interested in social inclusion and that of US policy more interested in market competitiveness. We seek to determine why policies directed at rural development in the EU and the USA differ. In both contexts new rural development policies emphasize partnership and participation but we find local participation is used to promote social inclusion in the EU and market competitiveness in the USA. An examination of these dimensions illustrates important transcontinental differences and similarities in rural development policies. We explore the socio-historical reasons for differences in the commitment to social inclusion, while also noting similarities in the priority of market competitiveness.
Resumo:
Most single-reed woodwind instrument models rely on a quasistationary approximation to describe the relationship between the volume flow and. the pressure difference across the reed channel. Semiempirical models based on the quasistationary approximation are very useful in explaining the fundamental characteristics of this family of instruments such as self-sustained oscillations and threshold of blowing pressure. However, they fail at explaining more complex phenomena associated with the fluid-structure interaction during dynamic flow regimes, such as the transient and steady-state behavior of the system as a function. of the mouthpiece geometry. Previous studies have discussed the accuracy of the quasistationary approximation but the amount of literature on the subject is sparse, mainly due to the difficulties involved in the measurement of dynamic flows in channels with an oscillating reed. In this paper, a numerical technique based on the lattice Boltzmann method and a finite difference scheme is proposed in order to investigate the characteristics of fully coupled fluid-structure interaction in single-reed mouthpieces with different channel configurations. Results obtained for a stationary simulation with a static reed agree very well with those predicted by the literature based on the quasistationary approximation. However, simulations carried out for a dynamic regime with dn oscillating reed show that the phenomenon associated with flow detachment and reattachment diverges considerably frorn the theoretical assumptions. Furthermore, in the case of long reed channels, the results obtained for the vena contracta factor are in significant disagreement with those predicted by theory. For short channels, the assumption of constant vena contracta was found to be valid for only 40% of the duty cycle. (c) 2007 Acoustical Society of America.
Resumo:
Single-phase microreactors and micro-heat-exchangers have been widely used in industrial and scientific applications over the last decade. In several cases, operation of microreactors has shown that their expected efficiency cannot be reached either due to non-uniform distribution of reactants between different channels or due to flow maldistribution between individual microreactors working in parallel. The latter problem can result in substantial temperature deviations between different microreactors resulting in thermal run away which could arise from an exothermicreaction. Thus advances in the understanding of heat transfer and fluid flow distribution continue to be crucial in achieving improved performance, efficiency and safety in microstructured reactors used for different applications. This paper presents a review of the experimental and numerical results on fluid flow distribution, heat transfer and combination thereof, available in the open literature. Heat transfer in microchannels can be suitably described by standard theory and correlations, but scaling effects (entrance effects, conjugate heat transfer, viscous heating, and temperature-dependent properties) have often to be accounted for in microsystems. Experiments with single channels are in good agreement with predictions from the published correlations. The accuracy of multichannel experiments is lower due to flow maldistribution. Special attention is devoted to theoretical and experimental studies on the effect of a flow maldistribution on the thermal and conversion response of catalytic microreactors. There view concludes with a set of design recommendations aimed at improving the reactor performance. (C) 2010 Elsevier Ltd. All rights reserved.
Resumo:
We retrieved synovial tissue and fluid samples from patients undergoing primary total hip replacement (THR) (n 15), revision of aseptically loose THR (n 12), primary total knee replacement (TKR) (n 13) and revision of aseptically loose TKR (n 6). Several histological parameters were assessed on a relative scale of 1-4. Primary TJRs were clinically evaluated for degree of osteoarthrosis. Revision TJRs were assessed for migration of the implant, gross loosening and the degree of radiolucency. Cytokine levels in synovial fluid were determined with ELISA.
Resumo:
Obestatin (OB(1-23) is a 23 amino acid peptide encoded on the preproghrelin gene, originally reported to have metabolic actions related to food intake, gastric emptying and body weight. The biological instability of OB(1-23) has recently been highlighted by studies demonstrating its rapid enzymatic cleavage in a number of biological matrices. We assessed the stability of both OB(1-23) and an N-terminally PEGylated analogue (PEG-OB(1-23)) before conducting chronic in vivo studies. Peptides were incubated in rat liver homogenate and degradation monitored by LC-MS. PEG-OB(1-23) was approximately 3-times more stable than OB(1-23). Following a 14 day infusion of Sprague Dawley rats with 50 mol/kg/day of OB(1-23) or a N-terminally PEGylated analogue (PEG-OB(1-23)), we found no changes in food/fluid intake, body weight and plasma glucose or cholesterol between groups. Furthermore, morphometric liver, muscle and white adipose tissue (WAT) weights and tissue triglyceride concentrations remained unaltered between groups. However, with stabilised PEG-OB(1-23) we observed a 40% reduction in plasma triglycerides. These findings indicate that PEG-OB(1-23) is an OB(1-23) analogue with significantly enhanced stability and suggest that obestatin could play a role in modulating physiological lipid metabolism, although it does not appear to be involved in regulation of food/fluid intake, body weight or fat deposition.
Resumo:
INTRODUCTION: Bronchiolitis is the most common lower respiratory tract infection in infants, occurring in a seasonal pattern, with highest incidence in the winter in temperate climates and in the rainy season in warmer countries. Bronchiolitis is a common reason for attendance at and admission to hospital.
METHODS AND OUTCOMES: We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of prophylactic interventions for bronchiolitis in high-risk children? What are the effects of measures to prevent transmission of bronchiolitis in hospital? What are the effects of treatments for children with bronchiolitis? We searched: Medline, Embase, The Cochrane Library, and other important databases up to July 2010 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
RESULTS: We found 59 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
CONCLUSIONS: In this systematic review we present information relating to the effectiveness and safety of the following interventions: antibiotics, bronchodilators (oral, inhaled salbutamol, inhaled adrenaline [epinephrine], hypertonic saline), chest physiotherapy, continuous positive airway pressure, corticosteroids, fluid management, heliox, montelukast, nasal decongestants, nursing interventions (cohort segregation, hand washing, gowns, masks, gloves, and goggles), oxygen, respiratory syncytial virus immunoglobulins, pooled immunoglobulins, or palivizumab (monoclonal antibody), ribavirin, or surfactants.
Resumo:
Inclusion is increasingly understood as an educational reform that responds to the diversity of all learners, challenging the marginalization, exclusion and underachievement which may result from all forms of ‘difference’. Leadership for inclusion is conceptualized here as driving a constant struggle to create shared meanings of inclusion and to build collaborative practice, an effort that needs to be rooted in critical practice lest it risk replicating existing patterns of disadvantage. In response to calls for further research that challenge how school leaders conceptualize inclusion and for research that investigates how leaders enact their understandings of inclusion, this paper aims to increase our understanding of the extent to which leadership vision can map onto a school’s culture and of the organizational conditions in schools that drive responses to diversity. We investigate the enactment of leadership for inclusion in the troubled context of Northern Ireland by looking at two schools that primarily aim to integrate Catholic and Protestant children but which are also sites for a range of other dimensions of student ‘difference’ to come together. Whilst the two schools express differing visions of the integration of Catholics and Protestants, leadership vision of inclusion is enacted by members of the school community with a consensus around this vision brought about by formal and informal aspects of school culture. Multiple and intersecting spheres of difference stimulate a concerted educational response in both schools but integration remains the primary focus. In this divided society, religious diversity poses a significant challenge to inclusion and further support is required from leaders to enable teachers to break through cultural restraints.