A new fragmentation mechanism of dendrite arms is proposed. The theoretical basis of this mechanism is a shift in the thermodynamical equilibrium at the solid–liquid interface due to the presence of ...elastic energy. This effect is modelled by the generalized Gibbs–Thomson condition Larché FC, Cahn JW. Acta Metallurgica. 1973;21:1051, where each term is calculated analytically using a simple Bernoulli–Euler beam model. The resulting non-linear system of ordinary differential equations is integrated in time using a fully implicit scheme. It is demonstrated that there is a critical level of loading, exceeding which causes a catastrophic reduction in the neck cross section, leading to dendrite detachment.
Self-Pinning on a Liquid Surface Antoine, C; Irvoas, J; Schwarzenberger, K ...
The journal of physical chemistry letters,
02/2016, Volume:
7, Issue:
3
Journal Article
Peer reviewed
We report on the first experimental evidence of a self-pinning liquid drop on a liquid surface. This particular regime is observed for a miscible heavier oil drop (dichloromethane) deposited on an ...aqueous solution laden by an ionic surfactant (hexadecyltrimethylammonium bromide). Experimental characterization of the drop shape evolution coupled to particle image velocimetry points to the correlation between the drop profile and the accompanying flow field. A simple model shows that the observed pinned stage is the result of a subtle competition between oil dissolution and surfactant adsorption.
Leatherback turtles Dermochelys coriacea nest across the Wider Caribbean Region (WCR), including at low densities in many Small Island Developing States (SIDS). Most (87.8%) WCR governments protect ...the species from direct harvest; however, gravid females are at risk as they pass through unprotected regimes, especially among Eastern Caribbean SIDS where mortality can threaten the remnant nesting assemblages that characterize most Caribbean islands. We summarize flipper tag recovery data of adult females moving between WCR States or between islands within States. Between January 2002 and December 2013, WC-series tags obtained from WIDECAST's Marine Turtle Tagging Centre in Barbados were attached to 3151 leatherbacks. Most (64.3%) were tagged in Eastern Caribbean SIDS, with the remainder tagged in Guyana, Venezuela, and Costa Rica. The majority of females continued to nest at the location of tagging, but 211 tagged females were recovered elsewhere on 240 occasions, including 22 different sites in 17 countries. Females travelled significantly greater straight line distances between locations in different nesting seasons (x = 218.9 km) than within nesting seasons (x = 160.6 km). Rates of within- and between-season recoveries (2.8 and 4.3%, respectively) are similar to previously published estimates, but are likely to be underestimates, as few of the 470 known nesting beaches in the WCR are nocturnally monitored. Our data support a North Caribbean nesting population, a Southern Caribbean/Guianas stock, and suggest the existence of a Central Antillean nesting population nesting primarily within Guadeloupe, Dominica, Martinique, and Saint Lucia.
Exercise programs do not belong to standard treatment within disease management programmes for diabetes mellitus type 2, up to now. For these reason the effects of a 10-week behaviour-oriented ...exercise programme have been evaluated focusing on change in activity behaviour and health-related qualitiy of life. 202 patients took part in the investigation. There were significant inbetween group differences in some aspects of the outcome parameters. The study presents useful information on how to modify existing DMPs successfully for improving patient treatment.
Solidification experiments and numerical simulations have been performed to improve the understanding of the complex interrelation between melt flow and the formation of dendritic structures during ...solidification of Al-Cu and Ga-In alloys. Melt flow induces various effects on grain morphology primarily caused by convective transport of solute, such as a facilitation of the growth of primary trunks or lateral branches, dendrite remelting, fragmentation or freckle formation depending on the dendrite orientation, the flow direction and intensity. Within this project special interest was focused on fragmentation and segregation phenomena. Natural convection is caused by density variations within the solidifying alloys. Forced convection was produced by electromagnetic stirring. X-ray radioscopy was applied as a powerful tool for the visualization of dendritic growth and coarsening.
Objectives. The objective of this work was to determine 1-year medical outcomes, nursing home transfer, and functional change of assisted living (AL) residents and their relationship to care. ...Methods. On-site interviews and observations regarding the status and care of 2,078 residents in 193 facilities across four states were conducted; follow-up was by telephone interview with care providers. Results. Annual mortality and transfer rates were 14.4 and 21.3 per 100 residents. The probability of hospitalization and new/worsening morbidities over a standardized quarter per 100 residents was 12.7 and 22.7. Standardized change in function was notable among those who were transferred or died and small among others. Facility characteristics did not generally relate to medical outcomes and transfer, and those that related to functional change were small and occurred across multiple functions. Facilities that are affiliated with another level of care were more likely to transfer; nurse staffing was favorable for hospitalization but not transfer; and aide turnover was protective for mortality. Discussion. No single component defines “good” AL care. Predictors and outcomes are inconsistent, and effect sizes are small. Therefore, practice and policy should not focus narrowly on any one area or restrict the type of care—this being welcome news that supports diversity to accommodate individual preferences.
This paper deals with the linear instability analysis of the spherical Couette flow of an electrically conducting fluid in the presence of an axial magnetic field. The numerical investigations are ...performed for different ratios,
η
= 0.5 and
η
= 0.6, and compared with Hollerbach’s work for
η
= 0.33 (Hollerbach in Proc R Soc 465:2003,
2009
). The corresponding instability diagrams, i.e., the critical values of the Reynolds number
Re
, the wave number, and the frequency on the Hartmann number
Ha
, are presented and accompanied by simulation of the transition between three-dimensional flow states of different symmetries. The characteristic subdivision of the linear stability curves into anti-symmetric modes, which is responsible for the instability at small
Ha
, and symmetric modes occurring at higher
Ha
is found for larger
η
, too. However, the extension of the stability corridor between the anti-symmetric and the symmetric modes increases nonlinearly with
η
. This offers the possibility to stabilize the basic flow up to high
Re
by appropriately increasing
Ha
.
This paper deals with the linear stability analysis of the convective flow of an electrically conducting fluid in a spherical gap in the presence of an axial magnetic field which is parallel to the ...vector of gravitational acceleration. The inner shell is warmer then the outer one (T1>T2). The numerical investigations are performed for the radii ratios η=R1R2=0.4–0.8. The corresponding stability diagrams, i.e. the critical values of the Grashof number Grc and the wave number mc, are presented in dependence on the Hartmann number Ha. We show that the critical Grashof number decreases with increasing η in the case of absence of the magnetic field. A steady axial magnetic field stabilizes the flow, i.e. Grc increases with the Hartmann number Ha for each η investigated. The instability sets in either as a Hopf bifurcation or a steady pitchfork bifurcation in dependence on η and Ha. The stability analysis is accompanied by simulation of the three-dimensional states. We found that according to the bifurcation type there are two classes of 3D states: steady and oscillatory. Consequences of the symmetry with respect to ±ϕ direction are discussed.
Summary
Background
The relationship between early onset eczema and food allergy among infants has never been examined in a population‐based sample using the gold standard for diagnosis, oral food ...challenge.
Objective
We characterised the risk of challenge‐proven food allergy among infants with eczema in the general population.
Methods
One‐year‐old infants (n = 4453 meeting criteria for this analysis) were assessed for history of eczema, received a nurse‐administered eczema examination and underwent skin prick testing to peanut, egg and sesame. Those with a detectable wheal to one of the test foods underwent an oral food challenge irrespective of wheal size. The risk of food allergy, stratified by eczema severity and age of onset, was estimated using multivariate logistic regression with population sampling weights.
Results
One in five infants with eczema were allergic to peanut, egg white or sesame, compared to one in twenty‐five infants without eczema (OR 6.2, 95% CI 4.9, 7.9, P < 0.001). The prevalence of peanut allergy was low in the absence of eczema (0.7% 95% CI 0.4, 1.1). Infants with eczema were 11.0 times more likely to develop peanut allergy (95% CI 6.6, 18.6) and 5.8 times more likely to develop egg allergy (95% CI 4.6, 7.4) by 12 months than infants without eczema. 50.8% of infants (95% CI 42.8, 58.9) with early eczema onset (<3 months) who required doctor‐prescribed topical corticosteroid treatment developed challenge‐proven food allergy.
Conclusion and Clinical Relevance
Eczema, across the clinical severity spectrum in infancy, is a strong risk factor for IgE‐mediated food allergy. Infants with eczema were six times more likely to have egg allergy and 11 times more likely to have peanut allergy by 12 months than infants without eczema. Our data suggest that a heightened awareness of food allergy risk among healthcare practitioners treating infants with eczema, especially if early onset and severe, is warranted.
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