Modified formula of Malus' law for Glan-Taylor polarizing prisms

A simple three-axis model has been developed, which has been successfully applied to the analysis of the light transmittance in spatial incident angle and the simulation of modified formula of Malus' law for Glan-Taylor prisms. Our results indicate that the fluctuations on the cosine squared curve are due to specific misalignments between the axis of the optical system, the optical axis of the prism and the mechanical axis (rotation axis) of prism, which results in the fact that different initial relative location of the to-be-measured-prism in the testing system corresponds to different shape of Malus' law curve. Methods to get absolutely smooth curve are proposed. This analysis is available for other kinds of Glan-type prisms. (C) 2004 Elsevier B.V. All rights reserved.

Approximate Solutions by Truncated Taylor Series Expansions of Nonlinear Differential Equations and Related Shadowing Property with Applications

This paper investigates the errors of the solutions as well as the shadowing property of a class of nonlinear differential equations which possess unique solutions on a certain interval for any admissible initial condition. The class of differential equations is assumed to be approximated by well-posed truncated Taylor series expansions up to a certain order obtained about certain, in general nonperiodic, sampling points t(i) is an element of [t(0), t(J)] for i = 0, 1, . . . , J of the solution. Two examples are provided.

Pluralismo, política e julgamento: para um projeto crítico à luz da filosofia de Charles Taylor

O objetivo da tese de doutorado consistirá na defesa de uma alternativa para os dilemas políticos concernentes à incomparabilidade no interior de uma comunidade específica ou entre comunidades distintas, presente nas discussões em torno do pluralismo contemporâneo. Esta via é inspirada nos conceitos de bens constitutivos, avaliações fortes e articulação, desenvolvidos pelo filósofo canadense Charles Taylor, e é também uma tentativa de se pensar acerca de um projeto de crítica política que leve em consideração a motivação como elemento incontornável para a filosofia prática. A incomparabilidade, isto é, impossibilidade de critérios no julgamento entre práticas específicas, mas com repercussões públicas, levanta a questão de até que ponto é possível avaliar e deliberar racionalmente sobre modos de vida distintos e, às vezes, auto-excludentes. Tal problemática pode ser vista fortemente no chamado debate liberal-comunitarista, na década de 1980, bem como em seus desdobramentos nas discussões acerca do multiculturalismo, na década seguinte. E ainda, mais recentemente, nos impasses em torno do papel da religião na esfera pública. Mais do que pontos divergentes acerca da questão do julgamento, os que essas discussões também evidenciam é um debate mais central acerca do lugar que pode ocupar a política diante de nossa situação bem como as categorias pelas quais compreendemos o fenômeno do pluralismo. Sob a alcunha de comunitarista, o pensamento de Taylor aparece como uma forma atrativa por não se submeter ao relativismo (a impossibilidade de critério) e tampouco a um universalismo forte (baseado em critérios gerais e anteriores às práticas), ao desenvolver uma ontologia fundada em um conflito de bens constitutivos em disputa, sem desconsiderar o fenômeno do pluralismo. Com efeito, isto se dá na medida em que diante de práticas divergentes e concorrentes há implícita ou explicitamente uma posição acerca de como e a partir de onde podemos nos posicionar criticamente frente ao pluralismo vigente, uma vez que movimentos, discursos e relações são construídos em nome daquilo que se apresenta efetivamente como valioso ou digno de respeito e admiração. Neste sentido, qualquer tentativa de avaliação já diz respeito a nossa compreensão: de nós, do mundo e de nossa relação com o mundo. Um projeto crítico, levando em consideração nossas fontes que impulsionam a ação, requer um olhar detalhado que o pensamento de Taylor pode oferecer, especialmente a partir da relação entre os conceitos supracitados.

Semblanzas Ictiológicas Iberoamericanas: Héctor Samuel Vera Alcaraz.

A través de esta nueva serie tratamos de conocer diferentes aspectos personales de los integrantes de la comunidad ictiológica iberoamericana. Esta iniciativa, comparte el espíritu y objetivo de las semblanzas nacionales buscando informalmente, otro punto de unión en la “comunidad de ictiólogos iberoamericanos”. Quizás esté equivocado en mi apreciación, pero creo que vale la pena este intento, ya que, con la colaboración generosa e insoslayable de los integrantes de este “universo”, señalaremos un registro en el tiempo de la Ictiología Neotropical.

Abundance and conservation status of the Yangtze finless porpoise in the Yangtze River, China

middle and lower reaches of the Yangtze River, China. It is the only freshwater population of porpoises in the world and is currently listed as Endangered by IUCN. In November and December 2006 we used two boats and line transect methods to survey the entire current range of the population, except for two lakes (Poyang and Dongting). Sighting results were similar for both boats, so we pooled all data and analyzed them using two line transect models and a strip transect model. All models produced similar estimates of abundance (1111, 1225 and 1000). We then added independent estimates of the number of porpoises from the two lakes for a total estimate of approximately 1800 porpoises. Our findings indicate that the population continues to decline and that its distribution is becoming more fragmented. Our current estimate in the main river is slightly less than half the estimate from surveys between 1984 and 1991 (which was probably an underestimate). We also found an apparent gap in the distribution of porpoises between Yueyang and Shishou (similar to 150 km), where sightings had previously been common. Continued threats to Yangtze finless porpoises include bycatch in unregulated and unselective fishing, habitat degradation through dredging, pollution and noise, vessel strikes and water development. Immediate protective measures are urgently needed to ensure the persistence of finless porpoises in the Yangtze River. The survey design and analytical methods developed in this study might be appropriate for surveys of cetaceans in other river systems. (c) 2008 Elsevier Ltd. All rights reserved.

First human-caused extinction of a cetacean species?

The Yangtze River dolphin or baiji ( Lipotes vexillifer), an obligate freshwater odontocete known only from the middle-lower Yangtze River system and neighbouring Qiantang River in eastern China, has long been recognized as one of the world's rarest and most threatened mammal species. The status of the baiji has not been investigated since the late 1990s, when the surviving population was estimated to be as low as 13 individuals. An intensive six-week multivessel visual and acoustic survey carried out in November-December 2006, covering the entire historical range of the baiji in the main Yangtze channel, failed to find any evidence that the species survives. We are forced to conclude that the baiji is now likely to be extinct, probably due to unsustainable by-catch in local fisheries. This represents the first global extinction of a large vertebrate for over 50 years, only the fourth disappearance of an entire mammal family since AD 1500, and the first cetacean species to be driven to extinction by human activity. Immediate and extreme measures may be necessary to prevent the extinction of other endangered cetaceans, including the sympatric Yangtze finless porpoise ( Neophocaena phocaenoides asiaeorientalis).

Small-scale turbulent fluctuations beyond Taylor's frozen-flow hypothesis

The space-time cross-correlation function C-T(r, tau) of local temperature fluctuations in turbulent Rayleigh-Benard convection is obtained from simultaneous two-point time series measurements. The obtained C-T(r, tau) is found to have the scaling form C-T(r(E), 0) with r(E)=[(r-U tau)(2)+ V-2 tau(2)](1/2), where U and V are two characteristic velocities associated with the mean and rms velocities of the flow. The experiment verifies the theory and demonstrates its applications to a class of turbulent flows in which the requirement of Taylor's frozen flow hypothesis is not met.

Approaching the Unapproached Light: Milton and the Romantic Visionary

Shears, J. (2006). Approaching the Unapproached Light: Milton and the Romantic Visionary. In G. Hopps and J. Stabler (Eds.), Romanticism and Religion from William Cowper to Wallace Stevens (pp.25-40). The Nineteenth Century Series. Aldershot: Ashgate. RAE2008

Some by-products of missions, by Isaac Taylor Headland.

http://www.archive.org/details/somebyproductsof013993mbp

China's new day; a study of events that have led to its coming, by Isaac Taylor Headland.

$u http://books.google.com/books?vid=OCLC02623863&id=mQz8gPn0et8C&a_sbrr=1 View book via Google

A retrospect / by J. Hudson Taylor.

http://www.archive.org/details/aretrospect00tayluoft