Life cycle energy and carbon analysis of domestic combined heat and power generators

Micro Combined Heat and Power (micro-CHP) generators combine the benefits of the high-efficiency cogeneration technology and microgeneration and is being promoted as a means of lowering greenhouse gas emissions by decentralizing the power network. Life Cycle Assessment of energy systems is becoming a part of decision making in the energy industry, helping manufacturers promote their low carbon devices, and consumers choose the most environmentally friendly options. This report summarizes a preliminary life-cycle energy and carbon analysis of a wall-hung gas-powered domestic micro-CHP device that is commercially available across Europe. Combining a very efficient condensing boiler with a Stirling engine, the device can deliver enough heat to cover the needs of a typical household (up to 24kW) while generating power (up to 1kW) that can be used locally or sold to the grid. Assuming an annual heat production of 20 MWh, the study has calculated the total embodied energy and carbon emissions over a 15 years operational lifetime at 1606 GJ and 90 tonnes of CO2 respectively. Assuming that such a micro CHP device replaces the most efficient gas-powered condensing boiler for domestic heat production, and the power generated substitutes electricity from the grid, the potential energy and carbon savings are around 5000 MJ/year and 530 kg CO2/year respectively. This implies a payback period of the embodied energy and carbon at 1.32 - 2.32 and 0.75 - 1.35 years respectively. Apart from the embodied energy and carbon and the respective savings, additional key outcomes of the study are the evaluation of the energy intensive phases of the device’s life cycle and the exploration of potential improvements

The radial evolution of the solar wind, 1-10 AU

The interplanetary plasma and magnetic field observations from 1 to 10 AU are reviewed. Over this distance no clear reduction in average speed is seen. The range of wind speeds becomes smaller though high speed streams are still observed. The density, temperature and magnetic field profiles become dominated by the large values seen in the co-rotating interaction regions. The temperature falls more slowly than would be expected from a simple, adiabatic model. Co-rotating shocks appear beyond approximately 3 AU in Voyager data as opposed to beyond approximately 1.5 AU in the Pioneer data. Reverse shocks appear later than forward shocks; reverse shocks do not begin to appear until approximately 4 AU; reverse shocks appear to decay more rapidly than forward shocks. No clear effect due to interaction with the interstellar medium was seen in this radial range

Viewpoints: A high-performance high-dimensional exploratory data analysis tool

Scientific data sets continue to increase in both size and complexity. In the past, dedicated graphics systems at supercomputing centers were required to visualize large data sets, but as the price of commodity graphics hardware has dropped and its capability has increased, it is now possible, in principle, to view large complex data sets on a single workstation. To do this in practice, an investigator will need software that is written to take advantage of the relevant graphics hardware. The Viewpoints visualization package described herein is an example of such software. Viewpoints is an interactive tool for exploratory visual analysis of large, high-dimensional (multivariate) data. It leverages the capabilities of modern graphics boards (GPUs) to run on a single workstation or laptop. Viewpoints is minimalist: it attempts to do a small set of useful things very well (or at least very quickly) in comparison with similar packages today. Its basic feature set includes linked scatter plots with brushing, dynamic histograms, normalization and outlier detection/removal. Viewpoints was originally designed for astrophysicists, but it has since been used in a variety of fields that range from astronomy, quantum chemistry, fluid dynamics, machine learning, bioinformatics, and finance to information technology server log mining. In this article, we describe the Viewpoints package and show examples of its usage.Comment: 18 pages, 3 figures, PASP in press, this version corresponds more closely to that to be publishe

Voices of the dead: Hades narratives in the Odyssey and Bacchylides’ Ode 5

This article identifies the influence of the Homeric ‘Poetics of Hades’ in Greek Lyric and argues for an aetiological relationship between the persistent presentation of the lyric poet’s subjective voice and the freedom of speech introduced in Homer’s Underworld. The article demonstrates this relationship through an examination of Bacchylides’ Ode 5 and argues that the lyric poet consciously innovates upon Homer’s underworld narratives by allowing his Meleager to occupy the stage and takes the audience through his agonising last minutes by describing what dying feels like in his own voice. In doing so, Bacchylides presents his audeience with a Meleager who glosses over his heroic actions and moments of glory in favour for a more emotional and subjective view of his past, filled with regret and self-pity. In this respect the hero is no different from the ghost of Achilles who dismisses honour after death for the simple privilege of seeing the light of the sun, or Agamemnon who is consumed by the memory of his wife’s treachery while having nothing to say about his glorious exploits at Troy. This powerful retelling of the story of a great epic hero of the past looks, I argue, simultaneously backwards and forwards, since on the one hand it is inherited from Homer’s ‘Poetics of Hades’, while on the other, it anticipates the emotional and unmediated voices of the heroes and heroines of the tragic stage

The Ionizing Radiation Interaction with Matter, the X-ray Computed Tomography Imaging, the Nuclear Medicine SPECT, PET and PET-CT Tomography Imaging

The mechanism of the ionizing radiation interaction with matter is described for heavy charged particles, electrons and photons. Those effects causing energy loss of the radiation with sequential effects of absorption or attenuation are presented. The features of some characteristic detector systems with the relative electronics and the data acquisition system (DAQ) are presented. Those detectors are related with the medical imaging sensor systems. The characteristics of the medical imaging process of the X-ray and nuclear imaging with SPECT, PET and the combination of PET-CT are presented. The computed X-ray tomography, called CT, and the nuclear medicine tomography are presented, implementing the most of the previous parts, as they are defined in PET and SPECT imaging plus the combination of PET with CT the PET-CT

Stream dynamics between 1 AU and 2 AU: A detailed comparison of observations and theory

A radial alignment of three solar wind stream structures observed by IMP-7 and -8 (at 1.0 AU) and Voyager 1 and 2 (in the range 1.4 to 1.8 AU) in late 1977 is presented. It is demonstrated that several important aspects of the observed dynamical evolution can be both qualitatively and quantitatively described with a single-fluid 2-D MHD numerical model of quasi-steady corotating flow, including accurate prediction of: (1) the formation of a corotating shock pair at 1.75 AU in the case of a simple, quasi-steady stream; (2) the coalescence of the thermodynamic and magnetic structures associated with the compression regions of two neighboring, interacting, corotating streams; and (3) the dynamical destruction of a small (i.e., low velocity-amplitude, short spatial-scale) stream by its overtaking of a slower moving, high-density region associated with a preceding transient flow. The evolution of these flow systems is discussed in terms of the concepts of filtering and entrainment

Homer and the Poetics of Hades

In this thesis I examine Homer’s use of Hades as a poetic resource that allows a different approach to the epic past than the one provided through Muse-inspired narrative. By portraying Hades as a realm where vision is not possible (A - ides), I argue, Homer creates a unique poetic environment in which social constraints and divine prohibitions are not applicable. The result is a narrative that emulates that of the Muses but at the same time is markedly distinct from it, as in Hades experimentation with, and alteration of, important epic forms and values can be pursued, giving rise to a different kind of poetics. I have called this the ‘Poetics of Hades.’ In the Iliad, Homer offers us a glimpse of how this alternative poetics works through the visit of Patroclus’ shade in Achilles’ dream. The recollection offered by the shade reveals an approach to its past in which regret, self-pity and a lingering memory of intimate and emotional moments displace an objective tone, and a traditional exposition of heroic values such as kleos and timē. I argue that the potential of Hades for providing alternative means of commemorating the past is more fully explored in the ‘Nekyia’ of Odyssey 11; there, Odysseus’ extraordinary ability to see (idein) the dead in Hades allows him to meet and interview the shades of heroines and heroes of the epic past. The absolute confinement of Hades allows the shades to recount their stories from their own personal point of view. The poetic implications of this, I argue, are important since by visiting Hades and listening to the stories of the shades Odysseus, and Homer with him, gain access to a tradition in which epic values associated with gender roles and even divine law are suspended, in favour of a more immediate and personally inflected approach to the epic past

EVALUATING THE ENDOPHYTIC FUNGAL COMMUNITY IN PLANTED AND WILD RUBBER TREES (Hevea brasiliensis)

The main objectives of this dissertation project were to characterize and compare the fungal endophytic communities associated with rubber trees (Hevea brasiliensis) distributed in wild habitats and under plantations. This study recovered an extensive number of isolates (more than 2,500) from a large sample size (190 individual trees) distributed in diverse regions (various locations in Peru, Cameroon, and Mexico). Molecular and classic taxonomic tools were used to identify, quantify, describe, and compare the diversity of the different assemblages. Innovative phylogenetic analyses for species delimitation were superimposed with ecological data to recognize operational taxonomic units (OTUs) or "putative species" within commonly found species complexes, helping in the detection of meaningful differences between tree populations. Sapwood and leaf fragments showed high infection frequency, but sapwood was inhabited by a significantly higher number of species. More than 700 OTUs were recovered, supporting the hypothesis that tropical fungal endophytes are highly diverse. Furthermore, this study shows that not only leaf tissue can harbor a high diversity of endophytes, but also that sapwood can contain an even more diverse assemblage. Wild and managed habitats presented high species richness of comparable complexity (phylogenetic diversity). Nevertheless, main differences were found in the assemblage's taxonomic composition and frequency of specific strains. Trees growing within their native range were dominated by strains belonging to Trichoderma and even though they were also present in managed trees, plantations trees were dominated by strains of Colletotrichum. Species of Trichoderma are known for their biocontrol properties, whereas species of Colletotrichum have been always associated with plant disease