AZEuS: An Adaptive Zone Eulerian Scheme for Computational MHD

A new adaptive mesh refinement (AMR) version of the ZEUS-3D astrophysical magnetohydrodynamical (MHD) fluid code, AZEuS, is described. The AMR module in AZEuS has been completely adapted to the staggered mesh that characterises the ZEUS family of codes, on which scalar quantities are zone-centred and vector components are face-centred. In addition, for applications using static grids, it is necessary to use higher-order interpolations for prolongation to minimise the errors caused by waves crossing from a grid of one resolution to another. Finally, solutions to test problems in 1-, 2-, and 3-dimensions in both Cartesian and spherical coordinates are presented.Comment: 52 pages, 17 figures; Accepted for publication in ApJ

Introduction to J. B. Erhard's 'Devil's Apology' (1795)

This is the introduction to “Johann Benjamin Erhard, ‘Devil’s Apology’(1795)”, translated by J. Clarke and C. Rhode, British Journal for the History of Philosophy, DOI: 10.1080/09608788.2018.1441805

Fichte, Hegel, and the Life and Death Struggle

Several commentators have argued that Hegel’s account of ‘self-consciousness’ in Chapter IV of the Phenomenology of Spirit can be read as an ‘immanent critique’ of Fichte’s idealism. If this is correct, it raises the question of whether Hegel’s account of ‘recognition’ in Chapter IV can be interpreted as a critique of Fichte’s conception of recognition as expounded in the Foundations of Natural Right. A satisfactory answer to this question will have to provide a plausible interpretation of the ‘life and death struggle’ as an immanent critique of Fichte’s account of recognition. This paper aims to provide such an interpretation. The first part of the paper provides a discussion of Fichte’s account of recognition that emphasizes its ‘epistemic’ concerns. The second part argues that Hegel’s account of the ‘life and death struggle’ can be read plausibly as a critique of Fichte’s account of recognition

Environmental impacts of renewable energy

This PhD study addresses the question of whether the environmental impact of renewable energy sources is related to the power flux density. The object was to examine whether there are some general rules concerning the environmental impact from renewable energy sources, and whether a common factor could be the power flux density, of unit kW/m2 as an underlying principle. The background and nature of the study are described with definitions of key concepts. The role of energy in the environment, powering the natural world and having a set of functions, are explained. The need for a general theory and the rationale is considered for eight primary renewable energy sources. The literature on environmental impact from these sources is reviewed. The theory and the hypothesis are explained with questions raised. A test devised to explore the relevant interactions (sediment transport and land use) is outlined, using data from a selection of well known hydro electric power developments. The 'Stream Power' concept and a variety of parameters were used for identifying losses of energy and power to a river's natural processes, resulting from impoundment dams. The test was carried out on the reservoir reach and the river downstream. It is concluded from applying the hypothesis to hydro electric power, that the environmental impact may indeed be related to the power flux density, for the two main impact parameters investigated, land use and sediment transport, though this is not conclusively statistically confirmed due to the small sample size. The hypothesis is extended in the Appendix to the other water based renewable energy sources, tidal barrage, marine current, and wave power, and to the lower energy flux density sources such as wind, solar and biomass. It is concluded tentatively that there is a qualitative argument that the environmental impact of all renewable energy sources may be related to power flux density, in terms of both land use and some functions in nature of the energy flow

Environmental Impacts of Renewable Energy: a literature review.

A selection of the literature describing the environmental impacts of eight different renewable energy sources is reviewed; hydro, biomass, geothermal, wind, tidal, solar, wave and ocean thermal. The importance and status of environmental impacts to renewable energy sources is discussed and the character of the literature is considered. Starting with hydro electric power, the literature encompasses different perspectives; advocates of expansion of HEP due to its environmental advantages, or those stressing ecological and geomorphological impacts on flora, fauna. Some reviews concern environmental protection policy, involving tradeoffs, policy choices and bargaining. The environmental impacts of various sources of biomass such as forestry, agriculture, domestic and industrial wastes, and biofuels are reviewed. Biomass production and conversion is covered through assessment of soil resources and net energy output, energy forestry impacts, pollution from combustion, improved technologies such as gassification, and incineration of wastes and landfill gas. Geothermal energy's impacts are discussed through reviewing literature concerning air, water, seismicity, and noise pollution, land use, subsidence and some protection policy developments. The impacts of wind energy are similarly covered by topic: visual impact, noise, safety, electromagnetic intereference, wildlife, land use, public acceptability and planning. Several works on tidal energy are reviewed including most of the existing tidal energy plants, in terms of impact on flora, fauna, water quality, sediments, drainage and flooding. Solar energy's impacts are considered for the various different technologies; passive, thermal, concentrator, photovoltaic, and the impacts of manufacturing. Some studies of potential impacts from wave energy have been reviewed and one of ocean thermal energy. A chapter reviews the general renewable environmental impact literature, and another provides a brief overview of the valuation and costing of impacts. The final chapter considers the role and effects of environmental impact studies on the development of the technology

Fichte's theory of Intersubjectivity

This thesis rejects the traditional picture of Fichte as a 'philosopher of subjectivity' who conceives of reality as the product of an 'absolute subject'. In opposition to this view, this thesis presents Fichte as a philosopher of intersubjectivity, whose primary concern is with relations between subjects. It argues that the true originality of Fichte's philosophy lies in his claim that intersubjectivity is a condition of the possibility of self- consciousness. Part 1 of this thesis defends Fichte's claim that Kant's transcendental idealism requires an account of how we recognize other rational beings. It seeks to demonstrate the necessity of such an account by examining the role of intersubjectivity within Kant's transcendental philosophy. Chapters 1, 2 and 3 deal, respectively, with the significance of intersubjectivity for Kant's accounts of theoretical reason, practical reason and the unity of reason. Part 2 of this thesis considers Fichte's attempt to develop a theory of intersubjectivity within his system of transcendental philosophy or Wissenschaftslehre. Chapter 4 considers Fichte's conception of such a system, and stresses the importance of political, ethical and pedagogical themes to this conception. Chapter 5 provides a detailed discussion of Fichte's first serious treatment of the topic of intersubjectivity — Some Lectures Concerning the Scholar's Vocation. Chapter 6 seeks to provide a reading of Fichte's first presentation of the 'foundations' of his system that is consistent with his concern with intersubjectivity. Chapters 7 provide an extensive discussion of Fichte's most complete presentation of his theory of intersubjectivity — the Foundations of Natural Right