2,624 research outputs found
Characterising the ‘in situ’ Thermal Behaviour of Selected Electrical Machine Insulation and Impregnation Materials
Bifurcations in a convection problem with temperature-dependent viscosity
A convection problem with temperature-dependent viscosity in an infinite
layer is presented. As described, this problem has important applications in
mantle convection. The existence of a stationary bifurcation is proved together
with a condition to obtain the critical parameters at which the bifurcation
takes place. For a general dependence of viscosity with temperature a numerical
strategy for the calculation of the critical bifurcation curves and the most
unstable modes has been developed. For a exponential dependence of viscosity on
temperature the numerical calculations have been done. Comparisons with the
classical Rayleigh-B\'enard problem with constant viscosity indicate that the
critical threshold decreases as the exponential rate parameter increases.Comment: 16 pages, 5 figure
Does abscisic acid affect strigolactone biosynthesis?
Strigolactones are considered a novel class of plant hormones that, in addition to their endogenous signalling function, are exuded into the rhizosphere acting as a signal to stimulate hyphal branching of arbuscular mycorrhizal (AM) fungi and germination of root parasitic plant seeds. Considering the importance of the strigolactones and their biosynthetic origin (from carotenoids), we investigated the relationship with the plant hormone abscisic acid (ABA).
Strigolactone production and ABA content in the presence of specific inhibitors of oxidative carotenoid cleavage enzymes and in several tomato ABA-deficient mutants were analysed by LC-MS/MS. In addition, the expression of two genes involved in strigolactone biosynthesis was studied.
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The carotenoid cleavage dioxygenase (CCD) inhibitor D2 reduced strigolactone but not ABA content of roots. However, in abamineSG-treated plants, an inhibitor of 9-cis-epoxycarotenoid dioxygenase (NCED), and the ABA mutants notabilis, sitiens and flacca, ABA and strigolactones were greatly reduced. The reduction in strigolactone production correlated with the downregulation of LeCCD7 and LeCCD8 genes in all three mutants.
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The results show a correlation between ABA levels and strigolactone production, and suggest a role for ABA in the regulation of strigolactone biosynthesis
A Comparative Study of the ReCell® Device and Autologous Spit-Thickness Meshed Skin Graft in the Treatment of Acute Burn Injuries.
Early excision and autografting are standard care for deeper burns. However, donor sites are a source of significant morbidity. To address this, the ReCell® Autologous Cell Harvesting Device (ReCell) was designed for use at the point-of-care to prepare a noncultured, autologous skin cell suspension (ASCS) capable of epidermal regeneration using minimal donor skin. A prospective study was conducted to evaluate the clinical performance of ReCell vs meshed split-thickness skin grafts (STSG, Control) for the treatment of deep partial-thickness burns. Effectiveness measures were assessed to 1 year for both ASCS and Control treatment sites and donor sites, including the incidence of healing, scarring, and pain. At 4 weeks, 98% of the ASCS-treated sites were healed compared with 100% of the Controls. Pain and assessments of scarring at the treatment sites were reported to be similar between groups. Significant differences were observed between ReCell and Control donor sites. The mean ReCell donor area was approximately 40 times smaller than that of the Control (P < .0001), and after 1 week, significantly more ReCell donor sites were healed than Controls (P = .04). Over the first 16 weeks, patients reported significantly less pain at the ReCell donor sites compared with Controls (P ≤ .05 at each time point). Long-term patients reported higher satisfaction with ReCell donor site outcomes compared with the Controls. This study provides evidence that the treatment of deep partial-thickness burns with ASCS results in comparable healing, with significantly reduced donor site size and pain and improved appearance relative to STSG
Convection in colloidal suspensions with particle-concentration-dependent viscosity
The onset of thermal convection in a horizontal layer of a colloidal
suspension is investigated in terms of a continuum model for binary-fluid
mixtures where the viscosity depends on the local concentration of colloidal
particles. With an increasing difference between the viscosity at the warmer
and the colder boundary the threshold of convection is reduced in the range of
positive values of the separation ratio psi with the onset of stationary
convection as well as in the range of negative values of psi with an
oscillatory Hopf bifurcation. Additionally the convection rolls are shifted
downwards with respect to the center of the horizontal layer for stationary
convection (psi>0) and upwards for the Hopf bifurcation (psi<0).Comment: 8 pages, 6 figures, submitted to European Physical Journal
Ternary phase equilibria in the systems Ti-Fe-C, Ti-Co-C and Ti-Ni-c: phase equilibria of the type metal carbonitride + graphite + nitrogen in the systems Ti-C-N, Zr-C-N, and Hf-C-N
Bolshevism and the Avant-Garde: Marxist Ideology and the Aesthetics of Soviet Film, 1923-28
When Eisenstein\u27s Strike burst onto the cultural scene in 1925, Soviet cinema began a creative odyssey that left to posterity a brilliant collection of films that redefined the manner in which audiences viewed them. Not only was the form of these films dynamic and innovative, but their content captured the heroic actions of a new historical subject, the revolutionary proletariat. As the Soviet State assumed control over the production of films, politics imprinted its indelible mark on the content of these films, especially as Stalin tightened his grip over all aspects of artistic life. The author of this project will draw upon a rich tradition of writings on Marxist aesthetics to evaluate the politics of Soviet film and to determine their contribution to communist aesthetics. Soviet film of the 1920s and 30s reflected the ideological currents present in the cultural life of Soviet society in these decades and the extent to which politics influenced the course of its evolution
"From ‘What the hell is going on?’ to the ‘Mushy middle ground’ to ‘getting used to a new normal’: Young people’s biographical narratives around navigating parental dementia"
The number of young people who have a parent with dementia is rising as a result of improvements in diagnosis of young onset variants and demographic shifts. There has, however, been very little research focusing on this group. Accounts elicited as part of the Perceptions and Experiences of Young People With a Parent With Dementia described the period, usually some years, leading up to a diagnosis of a dementia and then the progress of the condition post diagnosis. These narratives were characterised by confusion, uncertainty, trauma and distress as the young people struggled to make sense of the significant and often extreme, behavioural and attitudinal changes that were symptoms of the illness. This paper describes and discusses how the young people experienced and navigated the temporal messiness and consequent biographical disruption arising from parental dementia
Lubricated revolute joints in rigid multibody systems
The main purpose of this work is to present a general methodology for modeling lubricated revolute joints in constrained rigid multibody systems. In the dynamic analysis of journal-bearings, the hydrodynamic forces, which include both squeeze and wedge effects, generated by the lubricant fluid, oppose the journal motion. The hydrodynamic forces are obtained by integrating the pressure distribution evaluated with the aid of Reynolds’ equation, written for the dynamic regime. The hydrodynamic forces built up by the lubricant fluid are evaluated from the system state variables and included into the equations of motion of the multibody system. Numerical examples are presented in order to demonstrate the use of the methodologies and procedures described in this work.Fundação para a Ciência e a Tecnologia (FCT
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