The shear-driven Rayleigh problem for generalised Newtonian fluids

We consider a variant of the classical ‘Rayleigh problem’ (‘Stokes’s first problem’) in which a semi-infinite region of initially quiescent fluid is mobilised by a shear stress applied suddenly to its boundary. We show that self-similar solutions for the fluid velocity are available for any generalised Newtonian fluid, regardless of its constitutive law. We demonstrate how these solutions may be used to provide insight into some generic questions about the behaviour of unsteady, non-Newtonian boundary layers, and in particular the effect of shear thinning or thickening on the thickness of a boundary layer

Examining the momentary relationships between body checking and eating disorder symptoms in women with anorexia nervosa.

Body checking is common among individuals with anorexia nervosa (AN) and increases risk for dietary restriction. However, no study has examined whether body checking increases the immediate risk for engaging in other harmful weight loss behaviors, or whether this relationship is moderated by person-level traits. The current study utilized ecological momentary assessment (EMA) to examine whether (a) body checking predicted rapid use of weight loss behaviors, and (b) whether eating-related obsessionality/compulsivity moderated this relationship. Women with full or subthreshold anorexia nervosa (N = 118) completed a measure of eating-related obsessionality/compulsivity at baseline, followed by a 14-day EMA protocol during which they reported on body checking and weight loss behaviors (i.e., exercise, self-induced vomiting, laxative use, skipping meals, and increasing fluid intake). In a series of generalized linear mixed models, within-person effects indicated that momentary body checking significantly predicted subsequent meal skipping and using fluids to curb appetite. Between-person effects indicated that individuals who engage in more frequent body checking also engage in a higher frequency of self-induced vomiting, meal skipping, and use of fluids to curb appetite. An individuals degree of eating-related obsessionality/compulsivity did not moderate any of these relationships. Findings highlight body checking as an immediate precursor of dangerous weight loss behaviors among individuals with AN, and underscore the need for clinicians to address body checking during treatment

Spatial and Temporal Variation of Offshore Wind Power and its Values Along the Central California Coast

The analysis of the spatiotemporal variability of wind power remains limited during the planning stage of an offshore wind farm. This study provides a framework to investigate how offshore wind power varies along the Central California Coast over diurnal and seasonal time scales, which is critical for reliability and functionality of the grid system. We find that offshore wind power in this region peaks during evening hours across all seasons and maximizes in spring and summer. The timing of peak offshore wind power production better aligns with that of peak demand across California than solar and land-based wind power production, highlighting its potential to fill the supply gap when demand is high and power production from other renewable energy sources is low. We further assess the value of offshore wind power using demand-based and wholesale market metrics. Both metrics indicate high potential value of offshore wind power over most areas in this region. Finally, we show that the estimate of power production is significantly biased when using mean wind speeds that do not account for temporal variability, leading to potentially inaccurate predictions about locations that are expected to produce the most power. These results reiterate the importance in considering spatiotemporal variability in wind power for accurately calculating the value of offshore wind development