Examples of public engagement with liquid crystal science

Public engagement is of increasing importance for scientists in all disciplines. From inspiring the next generation to tackling the under-representation of marginalised groups, public engagement is essential for building an improved and growing scientific landscape. This article outlines some examples of our public engagement activities in liquid crystal science as part of our ongoing EPSRC-funded project, Control of free-surface morphologies in anisotropic liquids

Weak-anchoring effects in a thin pinned ridge of nematic liquid crystal

A theoretical investigation of weak-anchoring effects in a thin two-dimensional pinned static ridge of nematic liquid crystal resting on a flat solid substrate in an atmosphere of passive gas is performed. Specifically, we solve a reduced version of the general system of governing equations recently derived by Cousins et al. [Proc. Roy. Soc. A}, 478(2259):20210849, 2022] valid for a symmetric thin ridge under the one-constant approximation of the Frank--Oseen bulk elastic energy with pinned contact lines to determine the shape of the ridge and the behaviour of the director within it. Numerical investigations covering a wide range of parameter values indicate that the energetically-preferred solutions can be classified in terms of the Jenkins--Barratt--Barbero--Barberi critical thickness into five qualitatively different types of solution. In particular, the theoretical results suggest that anchoring breaking occurs close to the contact lines. The theoretical predictions are supported by the results of physical experiments for a ridge of the nematic 4'-pentyl-4-biphenylcarbonitrile (5CB). In particular, these experiments show that the homeotropic anchoring at the gas--nematic interface is broken close to the contact lines by the stronger rubbed planar anchoring at the nematic--substrate interface. A comparison between the experimental values of and the theoretical predictions for the effective refractive index of the ridge gives a first estimate of the anchoring strength of an interface between air and 5CB to be $(9.80\pm1.12)\times10^{-6}\,{\rm N m}^{-1}$ at a temperature of $(22\pm1.5)^\circ$C

Migration and household adaptation in climate-sensitive hotspots in South Asia

This is the final version. Available from Springer Nature via the DOI in this record. Purpose of Review: South Asia is highly vulnerable to the impacts of climate change, owing to the high dependency on climate-sensitive livelihoods and recurrent extreme events. Consequently, an increasing number of households are adopting labour migration as a livelihood strategy to diversify incomes, spread risks, and meet aspirations. Under the Collaborative Adaptation Research Initiative in Africa and Asia (CARIAA) initiative, four research consortia have investigated migration patterns and their inherent linkages to adaptation to climate change in climate hotspots. This article synthesizes key findings in regional context of South Asia. Recent Findings: The synthesis suggests that in climate-sensitive hotspots, migration is an important livelihood diversification strategy and a response to various risks, including climate change. Typically, one or more household members, often young men, migrated internally or internationally to work in predominantly informal sectors. Remittances helped spatially diversify household income, spread risks, and insure against external stressors. The outcomes of migration are often influenced by who moves, where to, and what capacities they possess. Summary: Migration was found to help improve household adaptive capacity, albeit in a limited capacity. Migration was mainly used as a response to risk and uncertainty, but with potential to have positive adaptation co-benefits.International Development Research Centr

Weak-anchoring effects in a thin pinned ridge of nematic liquid crystal

A theoretical investigation of weak-anchoring effects in a thin two-dimensional pinned static ridge of nematic liquid crystal resting on a flat solid substrate in an atmosphere of passive gas is performed. Specifically, we solve a reduced version of the general system of governing equations recently derived by Cousins et al. [Proc. R. Soc. A 478, 20210849 (2022)] valid for a symmetric thin ridge under the one-constant approximation of the Frank-Oseen bulk elastic energy with pinned contact lines to determine the shape of the ridge and the behavior of the director within it. Numerical investigations covering a wide range of parameter values indicate that the energetically preferred solutions can be classified in terms of the Jenkins-Barratt-Barbero-Barberi critical thickness into five qualitatively different types of solution. In particular, the theoretical results suggest that anchoring breaking occurs close to the contact lines. The theoretical predictions are supported by the results of physical experiments for a ridge of the nematic 4 ′ -pentyl-4-biphenylcarbonitrile (5CB). In particular, these experiments show that the homeotropic anchoring at the gas-nematic interface is broken close to the contact lines by the stronger rubbed planar anchoring at the nematic-substrate interface. A comparison between the experimental values of and the theoretical predictions for the effective refractive index of the ridge gives a first estimate of the anchoring strength of an interface between air and 5CB to be (9.80 ± 1.12) × 10^(− 6) Nm^(−1) at a temperature of (22 ± 1.5)∘C

A global assessment of actors and their roles in climate change adaptation

An assessment of the global progress in climate change adaptation is urgently needed. Despite a rising awareness that adaptation should involve diverse societal actors and a shared sense of responsibility, little is known about the types of actors, such as state and non-state, and their roles in different types of adaptation responses as well as in different regions. Based on a large n-structured analysis of case studies, we show that, although individuals or households are the most prominent actors implementing adaptation, they are the least involved in institutional responses, particularly in the global south. Governments are most often involved in planning and civil society in coordinating responses. Adaptation of individuals or households is documented especially in rural areas, and governments in urban areas. Overall, understanding of institutional, multi-actor and transformational adaptation is still limited. These findings contribute to debates around ‘social contracts’ for adaptation, that is, an agreement on the distribution of roles and responsibilities, and inform future adaptation governance

Adaptation policy and practice in densely populated glacier-fed river basins of South Asia: a systematic review

10.1007/s10113-014-0711-zRegional Environmental Change155825-83

Active control of the free surface of a rivulet of a nematic liquid crystal with an electric field

Active control of a rivulet of a nematic liquid crystal is achieved by local modification of the effective viscosity with an applied electric field. Specifically, using the nematic 5CB, control of the free surface of the rivulet is achieved through manipulation of the effective viscosity induced by the competition of moments due to viscous shear stress alignment and electric field alignment. The experimentally observed dependencies of the rivulet height on the volume flux and the strength of the applied electric field are successfully captured by a theoretical model based on the Ericksen-Leslie equations

Flow manipulation of a nematic liquid crystal in a Hele-Shaw cell with an electrically-controlled viscous obstruction

The flow of a nematic liquid crystal in a Hele-Shaw cell with an electrically controlled viscous obstruction is investigated using both a theoretical model and physical experiments. The viscous obstruction is created by temporarily electrically altering the viscosity of the nematic in a region of the cell across which an electric field is applied. The theoretical model is validated experimentally for a circular cylindrical obstruction, demonstrating user-controlled flow manipulation of an anisotropic liquid within a heterogeneous single-phase microfluidic device

Designing policies that can adapt to a world of uncertainty, change and surprise : adaptive policymaking for agriculture and water resources; interim technical report, Apr. 1 - Sept. 30, 2005

Draf