Fuel cells for power generation and organic waste treatment on the island of Mull

In-situ use of biomass and organic waste streams have the potential to provide the key to energy self sustainability for islands and remote communities. Traditionally biogas fuels have been used in combustion engines for electric power generation. However, fuel cells offer the prospect of achieving higher generating efficiencies, and additionally, important environmental benefits can be achieved by way of mitigating greenhouse gas emissions, whilst providing a carbon sink. This paper presents the design details of a biogas gas plant and fuel cell installation that will provide a practical solution on an island (and be applicable in other remote and rural areas) where connection to the grid can be expensive, and where biofuels can be produced on site at no significant extra cost

Application of the Yin-Yang grid to a thermal convection of a Boussinesq fluid with infinite Prandtl number in a three-dimensional spherical shell

A new numerical finite difference code has been developed to solve a thermal convection of a Boussinesq fluid with infinite Prandtl number in a three-dimensional spherical shell. A kind of the overset (Chimera) grid named ``Yin-Yang grid'' is used for the spatial discretization. The grid naturally avoids the pole problems which are inevitable in the latitude-longitude grids. The code is applied to numerical simulations of mantle convection with uniform and variable viscosity. The validity of the Yin-Yang grid for the mantle convection simulation is confirmed

A cost-effectiveness analysis of temperate silvoarable systems: what contribution do ecosystem services make?

Silvoarable systems have the potential to be an effective and productive form of sustainable agriculture, in part due to the enhancement of biodiversity and associated ecosystem services. However, currently there is limited understanding of how higher biodiversity in silvoarable systems promotes ecosystem services, such as pest regulation, pollination and nutrient cycling (for example, see Peng et al. 1993; Thevathasan and Gordon 2004; Varah et al. 2013), versus ecosystem disservices, such as encouraging certain pests and weeds (Griffiths et al. 1998; Burgess et al. 2003), and, furthermore, how this cost-benefit ratio might change with how the system is designed, managed and matures over time (but see Burgess et al 2003; Stamps et al. 2009). This paper reports on preliminary results of a cost effectiveness analysis based on the FarmSAFE model (Graves et al. 2011; 2016), as part of a PhD investigating how management of silvoarable influences biodiversity-derived ecosystem services, and their economic implications. Our study is focussed on silvoarable systems in the UK that combine top-fruit production with arable alley-cropping, which are emerging as a promising design with limited shade effects (Smith et al. 2016). We compare our findings to a monocropped arable system, with and without purported associated biodiversity benefits (Varah et al. 2013, 2015)

An axis-free overset grid in spherical polar coordinates for simulating 3D self-gravitating flows

A type of overlapping grid in spherical coordinates called the Yin-Yang grid is successfully implemented into a 3D version of the explicit Eulerian grid-based code PROMETHEUS including self-gravity. The modified code successfully passed several standard hydrodynamic tests producing results which are in very good agreement with analytic solutions. Moreover, the solutions obtained with the Yin-Yang grid exhibit no peculiar behaviour at the boundary between the two grid patches. The code has also been successfully used to model astrophysically relevant situations, namely equilibrium polytropes, a Taylor-Sedov explosion, and Rayleigh-Taylor instabilities. According to our results, the usage of the Yin-Yang grid greatly enhances the suitability and efficiency of 3D explicit Eulerian codes based on spherical polar coordinates for astrophysical flows.Comment: 15 pages, 17 figures, 2 tables, accepted for publication in A&

Multigrid elliptic equation solver with adaptive mesh refinement

In this paper we describe in detail the computational algorithm used by our parallel multigrid elliptic equation solver with adaptive mesh refinement. Our code uses truncation error estimates to adaptively refine the grid as part of the solution process. The presentation includes a discussion of the orders of accuracy that we use for prolongation and restriction operators to ensure second order accurate results and to minimize computational work. Code tests are presented that confirm the overall second order accuracy and demonstrate the savings in computational resources provided by adaptive mesh refinement.Comment: 12 pages, 9 figures, Modified in response to reviewer suggestions, added figure, added references. Accepted for publication in J. Comp. Phy

Disposal of Metropolitan Sewage.

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Integrating Mindfulness into School Classrooms

This senior capstone research project examines how mindfulness could be integrated into the school classrooms through the use of literature review, interviews with elementary school teachers in the Monterey Bay area and surveys with several students along with one subject participant at the California State University Monterey Bay. As a result, the findings reveal that most students and teachers thought that mindfulness proved to be successful and useful when integrating it with the younger population to deal with their emotions

Online Anonymity and the Kantian Publicity Principle: Can the Internet Solve the Paradox of Tyranny?

Immanuel Kant’s publicity maxim states that other-regarding actions are wrong if their maxim is not compatible with their being made public. This has the effect of forbidding dissent or rebellion against tyranny, since rebels cannot make their intentions and plans public. However, new internet technologies offer public speech from behind the “shield” of anonymity, allowing dissent to be public but preventing reprisals from tyrants. This thesis examines not only this possibility, but the value of internet-based discursive spaces for politics, their viability as a mode for political communication, and their implications for Classical and Enlightenment approaches to politics and intellectual virtue. Anonymous internet communications favour logos-based reasoning and discourse, which, in the liberal-democratic tradition, is preferable to phronesis and its attendant elitism and chauvinism. These technologies can open new vistas for liberal-democratic politics

The "Yin-Yang Grid": An Overset Grid in Spherical Geometry

A new kind of overset grid, named Yin-Yang grid, for spherical geometry is proposed. The Yin-Yang grid is composed of two identical component grids that are combined in a complemental way to cover a spherical surface with partial overlap on their boundaries. Each component grid is a low latitude part of the latitude-longitude grid. Therefore the grid spacing is quasi-uniform and the metric tensors are simple and analytically known. One can directly apply mathematical and numerical resources that have been written in the spherical polar coordinates or latitude-longitude grid. The complemental combination of the two identical component grids enables us to make efficient and concise programs. Simulation codes for geodynamo and mantle convection simulations using finite difference scheme based on the Yin-Yang grid are developed and tested. The Yin-Yang grid is suitable for massively parallel computers.Comment: 9 figure