Atomic physics with hard X-rays from high brilliance synchrotron light sources

A century after the discovery of x rays, the experimental capability for studying atomic structure and dynamics with hard, bright synchrotron radiation is increasing remarkably. Tempting opportunities arise for experiments on many-body effects, aspects of fundamental photon-atom interaction processes, and relativistic and quantum-electrodynamic phenomena. Some of these possibilities are surveyed in general terms

Remote sensing of energetic electron precipitation

Charged particles trapped in Earth's magnetic fields slam or precipitate into the atmosphere during geomagnetic disturbances in the Near-Earth space environment. The particles ionize, excite, and heat the neutral gas, leading to the optical aurora. Below the peak of optical auroral emissions is the ionospheric D-region extending from 70--90 km. Here, in the night time, D-region ionization occurs mainly due to sub-relativistic (100--500 keV) and relativistic (~>500 keV) electron precipitation causing Ultraviolet, X-ray, and faint optical emissions. We can also detect its presence through electron density measurements from Incoherent Scatter Radars. Though the magnetospheric source regions of the precipitation are broadly known, a more constrained estimate of the location and mechanism is needed, especially during magnetic activity. Energetic electron precipitation is also known to cause changes in the upper atmospheric chemistry, increase in ionospheric conductance, and attenuation of radio signals in high-latitude regions. However, a quantitative estimate of these effects has been challenging to obtain due to sparse measurements. This dissertation introduces techniques to measure energetic electron precipitation and its associated auroral forms in the ionosphere, and methods to constrain its sources during magnetically active periods such as substorms. We primarily address the following questions: 1) What are the magnetospheric source regions of energetic electron precipitation observed during substorms? 2) What is the effect of these particles on the atmosphere? By synthesizing measurements from Incoherent Scatter Radars, ground-based optical cameras, and satellites, we identify the two main sources of energetic precipitation during substorms: the near-Earth plasma sheet and the outer radiation belt boundary. The plasma sheet is a thin sheet-like region with a relatively high plasma density, close to the magnetic equatorial plane, between the dipolar field region and the stretched magnetotail. The outer radiation belts are regions of trapped high energy charged particles in the dipolar fields ranging from ~3 to ~10 RE. For the first time, we identified the existence of the outer radiation belt boundary's auroral signature, which is present in at least 40% of strong substorms. These energetic electrons also cause the majority of the high-latitude ionosphere's peak Hall conductance during substorms. The source regions of energetic electron precipitation explored in this dissertation lie in the nightside dipolar transition region - a relatively unexplored part of the magnetosphere. This work will be useful for future explorations of this region, especially for new missions such as the Transition Region Explorer (TREX). The remote sensing effort presented in this dissertation enhances the community's understanding of multi-scale processes that meet the scope of NASA's Heliophysics System observatory. This dissertation provides an extensive background of energetic particle precipitation and its role in the magnetosphere-ionosphere system and a detailed discussion on remote-sensing techniques to constrain precipitation sources using magnetically conjugate measurements

Methods of symmetry reduction and their application

In this thesis methods of symmetry reduction are applied to several physically relevant partial differential equations. The first chapter serves to acquaint the reader with the symmetry methods used in this thesis. In particular the classical method of Lie, an extension of it by Bluman and Cole [1969], known as the nonclassical method, and the direct method of Clarkson and Kruskal [1989] are described. Other known extensions of these methods are outlined, including potential symmetries, introduced by Bluman, Kumei and Reid [1988]. Also described are the tools used in practice to perform the calculations. The remainder of the thesis is split into two parts. In Part One the classical and nonclassical methods are applied to three classes of scalar equation: a generalised Boussinesq equation, a class of third order equations and a class of fourth order equations. Many symmetry reductions and exact solutions are found. In Part Two each of the classical, nonclassical and direct methods are applied to various systems of partial differential equations. These include shallow water wave systems, six representations of the Boussinesq equation and a reaction-diffusion equation written as a system. In Chapters Five and Six both the actual application of these methods and their results is compared and contrasted. In such applications, remarkable phenomena can occur, in both the nonclassical and direct methods. In particular it is shown that the application of the direct method to systems of equations is not as conceptually straightforward as previously thought, and a way of completing the calculations of the nonclassical method via hodograph transformations is introduced. In Chapter Seven it is shown how more symmetry reductions may be found via nonclassical potential symmetries, which are a new extension on the idea of potential symmetries. In the final chapter the relationship between the nonclassical and direct methods is investigated in the light of the previous chapters. The thesis is concluded with some general remarks on its findings and on possible future work

The development of the mathematical department of the Educational Times from 1847 to 1862.

Mathematics held an important place in the first twelve of years of the Educational Times (1847-1923), and in November 1848 a department of mathematical questions and solutions was launched. In 1864 this department was reprinted in a daughter journal: Mathematical Questions with Their solutions from The Educational Times (MQ). This thesis concentrates on the development of this department from its inception until 1862, when William John Clarke Miller became its editor; and is considered in terms of the editors, contributors and mathematics. To facilitate this research, a source-oriented database using K L E I O (kleio) software was constructed. It contains data taken from the questions and solutions and also miscellaneous items from the journal. Database analysis was used in conjunction with traditional, archival sources; for example, the respective, previously unknown correspondence of two of the main contributors, Thomas Turner Wilkinson and Miller. The development of the department fell into two main periods: the early 1850s when it was edited by Richard Wilson then James Wharton and had an educational bias; and the late 1850s when it was dominated by Miller and Stephen Watson who contributed moderately complex problems of a reasonably high standard on conic sections, probability and number theory. In 1850 Miller started contributing with a group of pupils and masters, including Robert Harley, from the Dissenters' College, Taunton. Another group of contributors which emerged was one of northern geometers, with whom Wilkinson was connected. He collaborated with Thomas Stephens Davies on geometry and this influenced his contributions to the department. Miller edited the department from 1862 to 1897 and MQ from 1863 to 1897 and made MO an international journal of renown for its original research. It contained contributions from some of the most eminent national and international mathematicians, including Cayley, Sylvester, Hirst and Clifford. The start of this new phase is briefly introduced and reviewed

History of Construction Cultures Volume 2

Volume 2 of History of Construction Cultures contains papers presented at the 7ICCH – Seventh International Congress on Construction History, held at the Lisbon School of Architecture, Portugal, from 12 to 16 July, 2021. The conference has been organized by the Lisbon School of Architecture (FAUL), NOVA School of Social Sciences and Humanities, the Portuguese Society for Construction History Studies and the University of the Azores. The contributions cover the wide interdisciplinary spectrum of Construction History and consist on the most recent advances in theory and practical case studies analysis, following themes such as: - epistemological issues; - building actors; - building materials; - building machines, tools and equipment; - construction processes; - building services and techniques ; -structural theory and analysis ; - political, social and economic aspects; - knowledge transfer and cultural translation of construction cultures. Furthermore, papers presented at thematic sessions aim at covering important problematics, historical periods and different regions of the globe, opening new directions for Construction History research. We are what we build and how we build; thus, the study of Construction History is now more than ever at the centre of current debates as to the shape of a sustainable future for humankind. Therefore, History of Construction Cultures is a critical and indispensable work to expand our understanding of the ways in which everyday building activities have been perceived and experienced in different cultures, from ancient times to our century and all over the world

History of Construction Cultures Volume 2

Volume 2 of History of Construction Cultures contains papers presented at the 7ICCH – Seventh International Congress on Construction History, held at the Lisbon School of Architecture, Portugal, from 12 to 16 July, 2021. The conference has been organized by the Lisbon School of Architecture (FAUL), NOVA School of Social Sciences and Humanities, the Portuguese Society for Construction History Studies and the University of the Azores. The contributions cover the wide interdisciplinary spectrum of Construction History and consist on the most recent advances in theory and practical case studies analysis, following themes such as: - epistemological issues; - building actors; - building materials; - building machines, tools and equipment; - construction processes; - building services and techniques ; -structural theory and analysis ; - political, social and economic aspects; - knowledge transfer and cultural translation of construction cultures. Furthermore, papers presented at thematic sessions aim at covering important problematics, historical periods and different regions of the globe, opening new directions for Construction History research. We are what we build and how we build; thus, the study of Construction History is now more than ever at the centre of current debates as to the shape of a sustainable future for humankind. Therefore, History of Construction Cultures is a critical and indispensable work to expand our understanding of the ways in which everyday building activities have been perceived and experienced in different cultures, from ancient times to our century and all over the world

Anuário Científico – 2009 & 2010 Resumos de Artigos, Comunicações, Teses, Patentes, Livros e Monografias de Mestrado

O Conselho Técnico-Científico do Instituto Superior de Engenharia de Lisboa (ISEL), na senda da consolidação da divulgação do conhecimento e da ciência desenvolvidos pelo nosso corpo docente, propõe-se publicar mais uma edição do Anuário Científico, relativa à produção científica de 2009 e 2010. A investigação, enquanto vertente estratégica do Instituto Superior de Engenharia de Lisboa (ISEL), tem concorrido para o seu reconhecimento nacional e internacional como instituição de referência e de qualidade na área do ensino das engenharias. É também nesta vertente que o ISEL consubstancia a sua ligação à sociedade portuguesa e internacional através da transferência de tecnologia e de conhecimento, resultantes da sua atividade científica e pedagógica, contribuindo para o seu desenvolvimento e crescimento de forma sustentada. São parte integrante do Anuário Científico todos os conteúdos com afiliação ISEL resultantes de resumos de artigos publicados em livros, revistas e atas de congressos que os docentes do ISEL apresentaram em fóruns e congressos nacionais e internacionais, bem como teses e patentes. Desde 2002, ano da publicação da primeira edição, temos assistido a uma evolução crescente do número de publicações de conteúdos científicos, fruto do trabalho desenvolvido pelos docentes que se têm empenhado com afinco e perseverança. Contudo, nestes dois anos (2009 e 2010) constatou-se um decréscimo no número de publicações, principalmente em 2010. Uma das causas poderá estar diretamente relacionada com a redução do financiamento ao ensino superior uma vez que limita toda a investigação no âmbito da atividade de I&D e da produção científica. Na sequência da implementação do Processo de Bolonha em 2006, o ISEL promoveu a criação de cursos de Mestrado disponibilizando uma oferta educativa mais completa e diversificada aos seus alunos, mas também de outras instituições, dotando-os de competências inovadoras apropriadas ao mercado de trabalho que hoje se carateriza mais competitivo e dinâmico. Terminados os períodos escolar e de execução das monografias dos alunos, os resumos destas são igualmente parte integrante deste Anuário, no que concerne à conclusão dos Mestrados em 2009 e 2010.A fim de permitir uma maior acessibilidade à comunidade científica e à sociedade civil, o Anuário Científico será editado de ora avante em formato eletrónico. Excecionalmente esta edição contempla publicações referentes a dois anos – 2009 e 2010

Basics of semiotics = Semiootika alused

http://www.ester.ee/record=b2046745*es