Topics in LIGO-related physics: interferometric speed meters and tidal work

In the quest to develop viable designs for third-generation optical interferometric gravitational-wave detectors, one strategy is to monitor the relative momentum or speed of the test-mass mirrors, rather than monitoring their relative position. The most straightforward design for a speed-meter interferometer that accomplishes this is described and analyzed in Chapter 2. This design (due to Braginsky, Gorodetsky, Khalili, and Thorne) is analogous to a microwave-cavity speed meter conceived by Braginsky and Khalili. A mathematical mapping between the microwave speed meter and the optical interferometric speed meter is developed and used to show (in accord with the speed being a quantum nondemolition observable) that in principle the interferometric speed meter can beat the gravitational-wave standard quantum limit (SQL) by an arbitrarily large amount, over an arbitrarily wide range of frequencies . However, in practice, to reach or beat the SQL, this specific speed meter requires exorbitantly high input light power. The physical reason for this is explored, along with other issues such as constraints on performance due to optical dissipation.

Chapter 3 proposes a more sophisticated version of a speed meter. This new design requires only a modest input power and appears to be a fully practical candidate for third-generation LIGO. It can beat the SQL (the approximate sensitivity of second-generation LIGO interferometers) over a broad range of frequencies (~ 10 to 100 Hz in practice) by a factor h/h_SQL ~ √W^(SQL)_(circ)/W_circ. Here W_circ is the light power circulating in the interferometer arms and W_SQL ≃ 800 kW is the circulating power required to beat the SQL at 100 Hz (the LIGO-II power). If squeezed vacuum (with a power-squeeze factor e^-2R) is injected into the interferometer's output port, the SQL can be beat with a much reduced laser power: h/h_SQL ~ √W^(SQL)_(circ)/W_circe^-2R. For realistic parameters (e^-2R ≃ 10 and W_circ ≃ 800 to 2000 kW), the SQL can be beat by a factor ~ 3 to 4 from 10 to 100 Hz. [However, as the power increases in these expressions, the speed meter becomes more narrow band; additional power and re-optimization of some parameters are required to maintain the wide band.] By performing frequency-dependent homodyne detection on the output (with the aid of two kilometer-scale filter cavities), one can markedly improve the interferometer's sensitivity at frequencies above 100 Hz.

Chapters 2 and 3 are part of an ongoing effort to develop a practical variant of an interferometric speed meter and to combine the speed meter concept with other ideas to yield a promising third- generation interferometric gravitational-wave detector that entails low laser power.

Chapter 4 is a contribution to the foundations for analyzing sources of gravitational waves for LIGO. Specifically, it presents an analysis of the tidal work done on a self-gravitating body (e.g., a neutron star or black hole) in an external tidal field (e.g., that of a binary companion). The change in the mass-energy of the body as a result of the tidal work, or "tidal heating," is analyzed using the Landau-Lifshitz pseudotensor and the local asymptotic rest frame of the body. It is shown that the work done on the body is gauge invariant, while the body-tidal-field interaction energy contained within the body's local asymptotic rest frame is gauge dependent. This is analogous to Newtonian theory, where the interaction energy is shown to depend on how one localizes gravitational energy, but the work done on the body is independent of that localization. These conclusions play a role in analyses, by others, of the dynamics and stability of the inspiraling neutron-star binaries whose gravitational waves are likely to be seen and studied by LIGO.

Interrelated contributions to freshwater science over 78 years: A guide to published work from the Freshwater Biological Association, Institute of Freshwater Ecology and Centre for Ecology and Hydrology, 1929-2006

This article introduces a new listing of published scientific contributions from the Freshwater Biological Association (FBA) and its later Research Council associates – the Institute of Freshwater Ecology (1989–2000) and the Centre for Ecology and Hydrology (2000+). The period 1929–2006 is covered. The authors offer also information on specific features of the listing; also an outline of influences that underlay the research, and its scientific scope.

Metaphysics in the Work of Charles Darwin

It is not hard to see how two visions of nature are intertwined in Darwin’s Journal of Researches: one vision, the province of romantic authors depicting the sentiments awakened by certain landscapes, the other, the domain of natural scientists describing the world without reference to the aesthetic qualities of the scenery. Nevertheless, analyses of this double perspective in Darwin’s work are relatively rare. Most scholars focus on Darwin, the scientist, and more or less ignore the aesthetic aspects of his work. Perceiving the gradual transformation of Darwin’s world view, however, depends on analyzing the two different modes in which Darwin approached and perceived the world. While one can, on occasion, find commentaries on the beauty of the natural world in Darwin’s early work, the passage of time produces a modification in the naturalist’s manner of perceiving nature. This does not, however, mean that Darwin ceases to find beauty in nature; on the contrary, the disenchantment, in Max Weber’s words, that Darwin’s theory produces should not be understood in a pejorative, but rather in a literal sense. The theory of evolution, in effect, divests nature of its magical character and begins to explain it in terms of natural selection, according it, in the process a new and more intense attraction. In the present work, the metaphysical implications of this new vision of the world are analyzed through the eyes of its discoverer.

Infiltration of fine and coarse sand into an open-work gravel bed

The siltation of an experimental gravel bed, with three grades of sand moving in suspension and as bedload, was examined. The rate of infiltration of sand into the void space of the gravel was determined under differing conditions of discharge, water depth, and velocity (jointly expressed as variation in the Froude Number) and suspended sediment concentration. The downstream reduction in siltation from the point source was also examined.

Published work on freshwater science from the FBA, IFE and CEH, 1929-2006

A new listing of published scientific contributions from the Freshwater Biological Association (FBA) and its later Research Council associates – the Institute of Freshwater Ecology (1989–2000) and the Centre for Ecology and Hydrology (2000+) is provided. The period 1929–2006 is covered. The compilation extends an earlier list assembled by in 1979.

We can work it out: an enactive look at cooperation

The past years have seen an increasing debate on cooperation and its unique human character. Philosophers and psychologists have proposed that cooperative activities are characterized by shared goals to which participants are committed through the ability to understand each other’s intentions. Despite its popularity, some serious issues arise with this approach to cooperation. First, one may challenge the assumption that high-level mental processes are necessary for engaging in acting cooperatively. If they are, then how do agents that do not possess such ability (preverbal children, or children with autism who are often claimed to be mind-blind) engage in cooperative exchanges, as the evidence suggests? Secondly, to define cooperation as the result of two de-contextualized minds reading each other’s intentions may fail to fully acknowledge the complexity of situated, interactional dynamics and the interplay of variables such as the participants’ relational and personal history and experience. In this paper we challenge such accounts of cooperation, calling for an embodied approach that sees cooperation not only as an individual attitude toward the other, but also as a property of interaction processes. Taking an enactive perspective, we argue that cooperation is an intrinsic part of any interaction, and that there can be cooperative interaction before complex communicative abilities are achieved. The issue then is not whether one is able or not to read the other’s intentions, but what it takes to participate in joint action. From this basic account, it should be possible to build up more complex forms of cooperation as needed. Addressing the study of cooperation in these terms may enhance our understanding of human social development, and foster our knowledge of different ways of engaging with others, as in the case of autism.

Redesenho urbanístico de assentamentos informais com vistas à conservação da água e sustentabilidade ambiental.

Essa Tese apresenta um framework para implementação de redesenho urbanístico de assentamentos informais no contexto da corrente atual do planejamento urbano integrado aos dos recursos hídricos, focado na conservação da água e na sustentabilidade ambiental. Entre outros, sugere-se a implantação do desenho urbanístico de forma participativa e colaborativa. Apresenta-se, de forma ilustrativa proposta de redesenho para a comunidade da Vila Cascatinha localizada na Baixada de Jacarepaguá, Rio de Janeiro, região de expansão da cidade, que serviu como objeto de estudo. A área do assentamento é de indefinição fundiária e atualmente é ocupada por aproximadamente 900 famílias. O framework baseia-se na corrente do urbanismo de baixo impacto, sobretudo do Low Impact Urban Design and Devolopment (LIUDD). Os dispositivos são implantados na escala local, de forma descentralizada para a conservação e manejo das águas pluviais no meio urbano. A pesquisa está inserida no Projeto HIDROCIDADES, desenvolvido dentro dos princícpios da metodologia de pesquisa-ação proposta por Thiollent. Foi realizado trabalho de campo e entrevistas guiadas, tendo sido identificado um percentual expressivo de moradores descendentes de antigos pequenos produtores agrícolas. Na pesquisa, moradores elencaram os principais problemas do assentamento. Além disso, foram diagnosticadas potencialidades dos moradores, dentro do conceito de Tecnologia Social. A prospecção entre os moradores também procurou verificar, em um contexto de colaboração, o conhecimento e a aderência dos moradores às estruturas urbanísticas praticadas no contexto da corrente Desenho Urbano de Baixo Impacto. Ao final deste processo foi gerada proposta de reurbanização sustentável do assentamento estudado, bem como proposta de moradias coletivas sustentáveis. Guardando as devidas especificidades, espera-se que a proposta apresentada possa ser aplicada a outros assentamentos de paisagem similar.

A inclusão de alunos com deficiência na UEPB: uma avaliação do Programa de Tutoria Especial

O presente estudo tem por objetivo avaliar as contribuições do Programa de Tutoria Especial da Universidade Estadual da Paraíba (UEPB) para a permanência e bom desempenho acadêmico dos seus alunos com deficiência no ensino superior. A pesquisa realizada, nessa Instituição de Ensino Superior, nos cursos de Pedagogia, História, Filosofia, Comunicação Social, Serviço Social, Direito e Física, contou como sujeitos: alunos com deficiência, seus respectivos tutores especiais, professores e a coordenadora do referido Programa. A investigação foi desenvolvida se utilizando de uma abordagem quantitativa e qualitativa, sendo do tipo exploratória e assumindo a forma de estudo de caso. Os procedimentos metodológicos de coleta de dados foram: análise documental, aplicação de questionários, entrevistas e registro de observações do comportamento. A pesquisa documental foi realizada durante todo o percurso da investigação, mediante acesso e análise de documentos e informações do Programa de Tutoria Especial. O questionário foi usado para a identificação e caracterização socioeconômica dos alunos com deficiência. A entrevista semiestruturada, foi aplicada aos vinte e seis sujeitos da pesquisa. Já, as sessões de observação do comportamento dos participantes foram conduzidas por meio de vinte sessões distribuídas em sala de aula e em atendimentos pedagógicos individualizados do Programa. Neste momento, procedemos, de maneira específica, ao estudo de caso de dois alunos com deficiência, integrantes da amostra dos sujeitos das entrevistas. Os resultados das entrevistas indicaram, dentre outros dados, que os sujeitos da pesquisa avaliaram o Programa de Tutoria Especial de forma positiva, alegando que o mesmo contribui tanto para a permanência dos alunos com deficiência na academia, quanto para o seu bom desempenho acadêmico. Na análise dos registros de observação, assim como das entrevistas, detectamos aspectos do Programa que ratificam, pontos que contrariam e pontos que necessitam ser incorporados à sua Resolução de criação (Resolução CONSEPE/UEPB N 013, de 07/07/2006). Os dados apontaram, portanto, a necessidade desta Resolução ser revista e reformulada para contemplar as novas demandas da dinâmica do Programa. Por fim, diante dos achados da investigação, levantamos a tese de que o Programa de Tutoria Especial da UEPB é um tipo de Atendimento Educacional Especializado (AEE) no ensino superior, com características e adaptações peculiares, ocorrendo de maneira diferenciada do AEE criado pelo Ministério da Educação, Cultura e Desporto (MEC) para a educação básica. Assim sendo, esta experiência da UEPB, sendo pioneira dentre as universidades brasileiras, poderá servir como uma proposta a ser socializada com outras universidades do país, uma vez que o MEC ainda não dispõe de uma política de AEE para o ensino superior.

Summary document of the work being done in 1992-1993 regarding the migratory salmonid fisheries of the River Ribble catchment

This document lists the work on salmonid fisheries in the River Ribble catchment in the north west of England which was done in 1992-93. The document includes the following: analysis of historical catch data from the River Ribble covering 1937-1991; Ribble and Hodder stock assessment surveys 1992-93 including Swanside Beck; Ribble catch data from game angling log books 1993; results of salmon scale sampling 1993; results of microtagging programme in Hodder and Ribble 1993; Waddow Weir dish counter data 1993; Winkley Hall (Hodder), Locks Weir and Waddow Hall (Ribble) fish counter data 1993; number of fish and ova from Witcherwell Hatchery 1993.