Minimax studies

Effect of nonzero initial conditions on selection of minimax controllers for large launch vehicles and extremal bounded amplitude bounded rate inputs to linear system

Design of hydraulic output Stirling engine

A hydraulic output system for the RE-1000 free piston stirling engine (FPSE) was designed. The hydraulic output system can be readily integrated with the existing hot section of RE-1000 FPSE. The system has two simply supported diaphragms which separate the engine gas from the hydraulic fluid, a dynamic balance mechanism, and a novel, null center band hydraulic pump. The diaphragms are designed to endure more than 10 billion cycles, and to withstand the differential pressure load as high as 14 MPa. The projected thermodynamic performance of the hydraulic output version of RE-1000 FPSE is 1.87 kW at 29/7 percent brake efficiency

UV-filter pollution: current concerns and future prospects.

UV-filters are widely used in cosmetics and personal care products to protect users' skin from redamage caused by ultraviolet (UV) radiation from the sun. Globally, an estimated 16,000 to 25,000 tonnes of products containing UV-filters were used in 2014 with modern consumption likely to be much higher. Beyond this use in cosmetics and personal care products, UV-filters are also widely used to provide UV-stability in industrial products such as paints and plastics. This review discusses the main routes by which UV-filters enter aquatic environments and summarises the conclusions of studies from the past 10 years that have investigated the effects of UV-filters on environmentally relevant species including corals, microalgae, fish, and marine mammals. Safety data regarding the potential impact of UV-filters on human health are also discussed. Finally, we explore the challenges surrounding UV-filter removal and research on more environmentally friendly alternatives to current UV-filters. [Abstract copyright: © 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG.

The Adjudication and Enforcement of Rights After Brexit

This report records the inaugural meeting and roundtable of the Brexit and Rights Engagement Network (BREN) on Tuesday 3rd July 2018 at Edinburgh Law School. Attendees at the roundtable included network members, fellow academics, representatives of the Scottish Parliament, the Scottish Government, the Scottish Human Rights Commission, the Equality and Human Rights Commission, the legal professions, and NGOs. Two years after the EU Referendum and only a few days after the European Union (Withdrawal) Act 2018 (the 2018 Act) receiving Royal Assent, the Brexit and Rights Engagement Network met for the first time. The purpose of the roundtable was to ignite debate amongst legal scholars and policy makers, and others working in a rights environment relating to interpretation, adjudication and enforcement of rights in the lead up to, and following “Brexit Day,” (March 29, 2019). This report is split into two sections, Part A will consider the adjudication of EU rights, but also their enforcement under the 2018 Act and the Withdrawal Agreement, whilst ‘options for the future’ will be broached in Part B

Supersymmetric Three-cycles and (Super)symmetry Breaking

We describe physical phenomena associated with a class of transitions that occur in the study of supersymmetric three-cycles in Calabi-Yau threefolds. The transitions in question occur at real codimension one in the complex structure moduli space of the Calabi-Yau manifold. In type IIB string theory, these transitions can be used to describe the evolution of a BPS state as one moves through a locus of marginal stability: at the transition point the BPS particle becomes degenerate with a supersymmetric two particle state, and after the transition the lowest energy state carrying the same charges is a non-supersymmetric two particle state. In the IIA theory, wrapping the cycles in question with D6-branes leads to a simple realization of the Fayet model: for some values of the CY modulus gauge symmetry is spontaneously broken, while for other values supersymmetry is spontaneously broken.Comment: 10 pages, harvmac big; v2, minor change

Stable and unstable attractors in Boolean networks

Boolean networks at the critical point have been a matter of debate for many years as, e.g., scaling of number of attractor with system size. Recently it was found that this number scales superpolynomially with system size, contrary to a common earlier expectation of sublinear scaling. We here point to the fact that these results are obtained using deterministic parallel update, where a large fraction of attractors in fact are an artifact of the updating scheme. This limits the significance of these results for biological systems where noise is omnipresent. We here take a fresh look at attractors in Boolean networks with the original motivation of simplified models for biological systems in mind. We test stability of attractors w.r.t. infinitesimal deviations from synchronous update and find that most attractors found under parallel update are artifacts arising from the synchronous clocking mode. The remaining fraction of attractors are stable against fluctuating response delays. For this subset of stable attractors we observe sublinear scaling of the number of attractors with system size.Comment: extended version, additional figur