On large bending deformations of transversely isotropic rectangular elastic blocks

In this paper we examine the classical problem of finite bending of a rectangular block of elastic material into a sector of a circular cylindrical tube in respect of compressible transversely isotropic elastic materials. More specifically, we consider the possible existence of isochoric solutions. In contrast to the corresponding problem for isotropic materials, for which such solutions do not exist for a compressible material, we determine conditions on the form of the strain-energy function for which isochoric solutions are possible. The results are illustrated for particular classes of energy function

Aerodynamic measuring device Patent

Pressure probe for sensing ambient static air pressure

Utilizing Highway Rest Areas for Electric Vehicle Charging: Economics and Impacts on Renewable Energy Penetration in California

California policy is incentivizing rapid adoption of zero emission electric vehicles for light-duty and freight applications. This project explored how locating charging facilities at California’s highway rest stops might impact electricity demand, grid operation, and integration of renewables like solar and wind into California’s energy mix. Assuming a growing population of electric vehicles to meet state goals, state-wide growth of electricity demand was estimated, and the most attractive rest stop locations for siting chargers identified. Using a California-specific electricity dispatch model developed at UC Davis, the project estimated how charging vehicles at these stations would impact renewable energy curtailment in California. It estimated the impacts of charging infrastructures on California’s electricity system and how they can be utilized to decrease the duck curve effect resulting from a large amount of solar energy penetration by 2050.View the NCST Project Webpag

‘There is no choice apart from antibiotics…’: qualitative analysis of views on urinary infections in pregnancy and antimicrobial resistance

Background: Antimicrobial resistance (AMR) is a health risk as it can lead to life-threatening infections. There has been a rise in resistant urinary tract infections (UTIs) which is the most common infection in pregnancy. This can be challenging in pregnancy due to the additional need to safeguard foetal development. The study's aim was to explore views about AMR in women who experienced UTIs in pregnancy. Design: Fifteen semi-structured interviews were conducted in the UK and analysed using thematic analysis. Results: Results highlighted two themes: conceptualization of AMR and pregnancy as a deviation from the norm, with an overarching theme of ‘self-efficacy’. Results show that participants were concerned about AMR but uncertain about the effect on society compared to individual's taking antibiotics and about completing antibiotic courses. Participants reported an unsparing use of antibiotics was justified in pregnancy, and behaviours like drinking adequate water were ineffective at preventing UTIs. In summary, women had low self-efficacy regards tackling AMR and managing their health. Conclusion: Misconceptions about how AMR affects society vs the individual translated into viewing it as a future problem to be tackled by the health-care sector. Consequently, AMR requires reconceptualization as a current problem requiring collective action. This research also indicates women endorse a biomedical model of UTIs in pregnancy which attributes resolving illness to interventions such as medicines, implying an automatic reliance on antibiotics. Subsequently, there is a need for self-efficacy by focusing on a behavioural model which emphasizes behaviours for infection prevention, thus reducing the need for antibiotics

An absence of a relationship between overt attention and emotional distortions to time: an eye-movement study

Emotional distortions to time are consistently reported in laboratory studies, however their underlying causes remain unclear. One suggestion is that emotion induced changes in attentional processes may contribute to emotional distortions to time. The current study tested this possibility by examining the relationship between eye-movement and perceptions of the duration of emotional events. Participants completed a verbal estimation task in which they estimated the duration of positively, negatively and neutrally valenced images from the International Affective Picture System images. Time to first fixation and dwell time were recorded throughout. The results showed no significant relationships between measures of eye-movement and measures of emotional distortion to time, despite the emotion manipulation successfully influencing the time before the participants first fixated on the to-be-timed stimulus. This suggests that for suprasecond intervals emotion induced changes in overt attention processing do not contribute towards emotional distortions to time

Elastic cavitation, tube hollowing, and differential growth in plants and biological tissues

Elastic cavitation is a well-known physical process by which elastic materials under stress can open cavities. Usually, cavitation is induced by applied loads on the elastic body. However, growing materials may generate stresses in the absence of applied loads and could induce cavity opening. Here, we demonstrate the possibility of spontaneous growth-induced cavitation in elastic materials and consider the implications of this phenomenon to biological tissues and in particular to the problem of schizogenous aerenchyma formation

Azimuthal shear of a transversely isotropic elastic solid

In this paper we study the problem of (plane strain) azimuthal shear of a circular cylindrical tube of incompressible transversely isotropic elastic material subject to finite deformation. The preferred direction associated with the transverse isotropy lies in the planes normal to the tube axis and is at an angle with the radial direction that depends only on the radius. For a general form of strain-energy function the considered deformation yields simple expressions for the azimuthal shear stress and the associated strong ellipticity condition in terms of the azimuthal shear strain. These apply for a sense of shear that is either “with” or “against” the preferred direction (anticlockwise and clockwise, respectively), so that material line elements locally in the preferred direction either extend or (at least initially) contract, respectively. For some specific strain-energy functions we then examine local loss of uniqueness of the shear stress–strain relationship and failure of ellipticity for the case of contraction and the dependence on the geometry of the preferred direction. In particular, for a reinforced neo-Hookean material, we obtain closed-form solutions that determine the domain of strong ellipticity in terms of the relationship between the shear strain and the angle (in general, a function of the radius) between the tangent to the preferred direction and the undeformed radial direction. It is shown, in particular, that as the magnitude of the applied shear stress increases then, after loss of ellipticity, there are two admissible values for the shear strain at certain radial locations. Absolutely stable deformations involve the lower magnitude value outside a certain radius and the higher magnitude value within this radius. The radius that separates the two values increases with increasing magnitude of the shear stress. The results are illustrated graphically for two specific forms of energy function