45 research outputs found

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

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    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

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    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

    Effect of carboplatin when administered after dacarbazine failure: Clinical benefit of sequential therapy

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    Dacarbazine chemotherapy has been the mainstay of melanoma treatment for >30 years. In the early 2000s, carboplatin (with or without other agents, such as paclitaxel) was the most commonly used second‑line therapy in the UK. The aim of the present study was to report a significant response rate to second‑line carboplatin in patients from three UK institutions who had been previously treated and failed to respond to dacarbazine, and investigate whether sequential therapy may be more effective compared with combination therapy. A total of 104 patients were identified, the majority of whom were treated with carboplatin (area under the curve 5‑6) every 3 weeks for a maximum of 6 cycles. A total of 102 patients were evaluable for response, among whom 11 patients had an objective response (1 complete response and 10 partial responses) and 15 had stable disease, giving an overall response rate of 11% and disease control rate of 26%. The median progression‑free survival was 1.8 months (range, 0.2‑36+ months) and the median overall survival was 4.6 months (range, 0.2‑36+ months). Surprisingly, the majority of the patients who benefited from second‑line carboplatin therapy were those with visceral metastases, the survival of whom would not be expected to exceed 6 months after first‑line treatment

    1960: Abilene Christian College Lectures - Full Text

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    Table of Contents: Theme Speeches: Christian Faith in the Modern World Basis of Faith - Leonard Mullens - 9 Authority in Christianity - John T. Smithson, Jr. - 27 Origin and Preservation of the Bible - Neil R. Lightfoot - 44 Alleged Discrepancies of the Bible - David H. Bobo - 62 The Unity of the Bible - Jack Meyer - 91 Faith and Reason - Joe Sanders - 115 The Reasonableness of Supernaturalism - Virgil Trout - 126 The Present Statue of the Doctrine of Organic Evolution - J.D. Thomas - 146 The Nature of Man - Roy F. Osborne, Jr. - 181 Modern Challenges to Christian Morals - Carl Spain - 199 The Christ, Whose Son is He? - Gordon Teel - 232 Special Speeches Teaching the Word of God in Korea - L. Haskell Chessfire - 255 The Influence of Christian Education - Judge Jack Pope - 276 Mission Opportunities in the Far East - Harry Robert Fox - 288 Mission Work in Austria - Robert Skelton - 303 Report from Switzerland - Heinrich Blum - 313 The Work in Nigeria - Rees Byrant - 320 The Training of Evangelists in Foreign Fields - Reiner Kallus - 331 Christian Scholarships - Everett Ferguson - 340 Evangelizing the World - A.R. Holton - 349 Panel Discussions The Significance of the Dead Sea Scrolls The Scrolls and the Text of the Bible - Paul Rotenberry - 357 The Relation between the Religion of the Essenes and that of Early Christians - Jay Smith - 366 Biblical Interpretation Expediency and Pattern Authority - J.W. Roberts - 381 Examples in Pattern Authority - Thomas B. Warren - 392 Mental Health and Sin The Present State of Mental Health Knowledge - Donald R. Sime - 409 The Relationship of Mental Health Problems to Sin - Paul Easley - 421 The Teenager The Problems of Youth - Mack Wayne Craig - 432 Influences for Good - Wyatt Sawyer - 443 The Benefits of Abilene Christian College To the Church - Hulen Jackson - 451 To The Home - Robert S. Bell - 459 \u27To the Community - Louie Welch - 465 Expenses At Abilene Christian College - James C. Kerr - 469 The Graduate School at Abilene Christian College What I Am Getting Now in the ACC Graduate Program - Harold Vanderpool - 475 How the ACC Graduate Program Has Stood Up - Everett Ferguson - 481 What the ACC Graduate Program Ought To Be - Frank Pack - 486 The Importance to the Church of the ACC Graduate Program A.R. Holton - 490 Beware: Large File Size Uploaded by Jackson Hage

    Energy planning tools for low carbon transitions: an example of a multicriteria spatial planning tool for district heating

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    Energy planning tools can support transitions to low carbon energy by helping planners to identify technology options and scenarios. Exploring a case study of district heating development to support heat decarbonisation in the United Kingdom (UK), this article uses thematic analysis of qualitative semistructured interviews conducted between May 2013 and August 2015 with local and regional government officials, in order to consider how energy planning decision-making tools can be designed to support the early stages of low carbon transitions as a form of strategic niche management. The findings of this analysis are then tested through the development of a spatial heat planning tool covering England and Wales, designed to respond to the needs of niche actors seeking to facilitate early development of district heating projects. The tool is for use by local government actors as they seek to build social networks of stakeholders to support the technology change, to demonstrate its value and to support skills development. The research shows the importance of designing flexible tools which can go beyond techno-economic criteria and reflect the wider motivations and decision criteria of local actors, including social criteria

    UK Local Authority engagement with the Energy Service Company (ESCo) model: key characteristics, benefits, limitations and considerations

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    © 2014 Elsevier Ltd.This paper explores how some UK Local Authorities (LAs) have opted to engage with the Energy Service Company (ESCo) model in a bid to enhance their influence over local energy system change and help them to deliver on their political public good objectives. Three common approaches to LA ESCo model engagement are outlined including the: (1) LA owned arms-length model; (2) private sector owned concession agreement model; and (3) community owned and run model. The LAs decision to establish its own ESCo, or alternatively enter into a partnership with another, predominantly depends on: its willingness to expose itself to risk, the level of strategic control it desires and the resources it has at its disposal. However, the business case is contingent on the extent to which the national policy and regulatory framework facilitates and obligates LAs to play an active energy governance role. Stronger alignment of local and national energy agendas through communication and coordination between different governance actors could help to remove critical barriers to LA ESCo engagement and their wider energy governance activities

    A pilot-scale comparison of mesophilic and thermophilic digestion of source segregated domestic food waste

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    Source segregated food waste was collected from domestic properties and its composition determined together with the average weight produced per household, which was 2.91 kg per week. The waste was fed over a trial period lasting 58 weeks to an identical pair of 1.5 m3 anaerobic digesters, one at a mesophilic (36.5°C) and the other at a thermophilic temperature (56°C). The digesters were monitored daily for gas production, solids destruction and regularly for digestate characteristics including alkalinity, pH, volatile fatty acid (VFA) and ammonia concentrations. Both digesters showed high VFA and ammonia concentrations but in the mesophilic digester the pH remained stable at around 7.4, buffered by a high alkalinity of 13,000 mg l-1; whereas in the thermophilic digester VFA levels reached 45,000 mg l-1 causing a drop in pH and digester instability. In the mesophilic digester volatile solids (VS) destruction and specific gas yield were favourable, with 67% of the organic solids being converted to biogas at a methane content of 58% giving a biogas yield of 0.63 m3 kg-1 VSadded. Digestion under thermophilic conditions showed potentially better VS destruction at 70% VS and a biogas yield of 0.67 m3 kg-1 VSadded, but the shifts in alkalinity and the high VFA concentrations required a reduced loading to be applied. The maximum beneficial loading that could be achieved in the mesophilic digester was 4.0 kg VS m-3 d-1

    Anaerobic digestion of source segregated domestic food waste: performance assessment by mass and energy balance

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    An anaerobic digester receiving food waste collected mainly from domestic kitchens was monitored over a period of 426 days. During this time information was gathered on the waste input material, the biogas production, and the digestate characteristics. A mass balance accounted for over 90% of the material entering the plant leaving as gaseous or digestate products. A comprehensive energy balance for the same period showed that for each tonne of input material the potential recoverable energy was 405 kWh. Biogas production in the digester was stable at 642 m3 tonne?1 VS added with a methane content of around 62%. The nitrogen in the food waste input was on average 8.9 kg tonne?1. This led to a high ammonia concentration in the digester which may have been responsible for the accumulation of volatile fatty acids that was also observed.<br/
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