University of Exeter

About: University of Exeter is a education organization based out in Exeter, United Kingdom. It is known for research contribution in the topics: Population & Context (language use). The organization has 15820 authors who have published 50650 publications receiving 1793046 citations. The organization is also known as: Exeter University & University of the South West of England.

Aggregation behavior of aqueous solutions of ionic liquids

Abstract: The aggregation behavior in aqueous solutions of three ionic liquids based on the 1-alkyl-3-methylimidazolium cation has been investigated by means of surface tension, conductivity, and small-angle neutron scattering (SANS) measurements. From analysis of the SANS data, models for the shapes and sizes of aggregates have been proposed: the short-chain 1-butyl-3-methylimidazolium tetrafluoroborate [C4mim][BF4] system can be best modeled by treating it as a dispersion of polydisperse spherical aggregates that form above a critical aggregation concentration, whereas the 1-octyl-3-methylimidazolium iodide, [C8mim][I], solutions can be modeled as a system of regularly sized near-spherical charged micelles that form above a critical micelle concentration. Solutions of 1-octyl-3-methylimidazolium chloride, [C8mim][Cl], display weak long-range ordering of possibly disklike particles culminating in the formation of structures with distinct long-range order at higher concentrations.

An astronomically dated record of Earth's climate and its predictability over the last 66 million years.

Abstract: Much of our understanding of Earth's past climate comes from the measurement of oxygen and carbon isotope variations in deep-sea benthic foraminifera. Yet, long intervals in existing records lack the temporal resolution and age control needed to thoroughly categorize climate states of the Cenozoic era and to study their dynamics. Here, we present a new, highly resolved, astronomically dated, continuous composite of benthic foraminifer isotope records developed in our laboratories. Four climate states-Hothouse, Warmhouse, Coolhouse, Icehouse-are identified on the basis of their distinctive response to astronomical forcing depending on greenhouse gas concentrations and polar ice sheet volume. Statistical analysis of the nonlinear behavior encoded in our record reveals the key role that polar ice volume plays in the predictability of Cenozoic climate dynamics.

Identification of 100 fundamental ecological questions

Abstract: Summary 1. Fundamental ecological research is both intrinsically interesting and provides the basic knowledge required to answer applied questions of importance to the management of the natural world. The 100th anniversary of the British Ecological Society in 2013 is an opportune moment to reflect on the current status of ecology as a science and look forward to high-light priorities for future work.

Early warning of climate tipping points

Abstract: A tipping point occurs when an external forcing causes a qualitative change in a system. Human-induced climate change could push several large elements of the climate system, such as the Greenland ice sheet, past a tipping point. Given the severity of the potential impacts, early warning of these changes would be advantageous. This Review discusses the most promising approaches to early warning of tipping points.

The Effects of Tropospheric Ozone on Net Primary Productivity and Implications for Climate Change

Abstract: Tropospheric ozone (O3) is a global air pollutant that causes billions of dollars in lost plant productivity annually. It is an important anthropogenic greenhouse gas, and as a secondary air pollutant, it is present at high concentrations in rural areas far from industrial sources. It also reduces plant productivity by entering leaves through the stomata, generating other reactive oxygen species and causing oxidative stress, which in turn decreases photosynthesis, plant growth, and biomass accumulation. The deposition of O3 into vegetation through stomata is an important sink for tropospheric O3, but this sink is modified by other aspects of environmental change, including rising atmospheric carbon dioxide concentrations, rising temperature, altered precipitation, and nitrogen availability. We review the atmospheric chemistry governing tropospheric O3 mass balance, the effects of O3 on stomatal conductance and net primary productivity, and implications for agriculture, carbon sequestration, and climate ch...