Modelagem e controle de posição e orientação de uma Plataforma de Stewart

Este trabalho apresenta o controle de posição e orientação de um modelo não linear de Plataforma de Stewart com seis graus de liberdade construído no ambiente de sistemas multicorpos ADAMS® desenvolvido pela Mechanical Dynamics, Inc. O modelo não linear é exportado para o ambiente SIMULINK® desenvolvido pela MathWorks, Inc., onde o controle de posição e orientação é realizado a partir da linearização do modelo e a aplicação de um sistema seguidor com realimentação de estados. Utililiza-se, também o SIMULINK® para implementar a dinâmica de um sistema servoválvula e cilindro hidráulico com um servocontrole de pressão e assim simular o comportamento dinâmico de um simulador de vôo com acionamento hidráulico. A utilização destes pacotes comerciais visa obter uma economia de tempo e esforço na modelagem de sistemas mecânicos complexos e na programação para obtenção da resposta do sistema no tempo, além de facilitar a análise de várias configurações de Plataformas de Stewart

Stars and brown dwarfs in the σ Orionis cluster (Research Note) III. OSIRIS/GTC low-resolution spectroscopy of variable sources

Context. Although many studies have been performed so far, there are still dozens of low-mass stars and brown dwarfs in the young σ Orionis open cluster without detailed spectroscopic characterisation. Aims. We look for unknown strong accretors and disc hosts that were undetected in previous surveys. Methods. We collected low-resolution spectroscopy (R ~ 700) of ten low-mass stars and brown dwarfs in σ Orionis with OSIRIS at the Gran Telescopio Canarias under very poor weather conditions. These objects display variability in the optical, infrared, Hα, and/or X-rays on time scales of hours to years. We complemented our spectra with optical and near-/mid-infrared photometry. Results. For seven targets, we detected lithium in absorption, identified Hα, the calcium doublet, and forbidden lines in emission, and/or determined spectral types for the first time. We characterise in detail a faint, T Tauri-like brown dwarf with an 18 h-period variability in the optical and a large Hα equivalent width of –125  ±  15 Å, as well as two M1-type, X-ray-flaring, low-mass stars, one with a warm disc and forbidden emission lines, the other with a previously unknown cold disc with a large inner hole. Conclusions. New unrevealed strong accretors and disc hosts, even below the substellar limit, await discovery among the list of known σ Orionis stars and brown dwarfs that are variable in the optical and have no detailed spectroscopic characterisation yet.

Private (Brown) Eyes: Ethnicity, Genre and Gender in Crime Fiction in the Gloria Damasco novels and the Chicanos Comic Series

The representation of women in crime fiction has traditionally been a complicated one. Consistently forced into secondary characters (assistants, girlfriends, or damsels in distress) the most active role a female character could aspire to was that of the femme fatale, a pit of perdition, an unwelcome distraction for a man looking for truth and justice. This traditional approach to the genre has been challenged in the last decades by women acting as detectives, trusted with solving their cases in a hostile male world. Similarly, the traditional white male protagonist has been contested by fictions where ethnic minorities are not just consigned to the criminal world, but where detectives are members of ethnic groups, and can use their knowledge of the community to solve the case. This essay focuses on the crossroads of ethnic and women’s detective fiction, specifically the Gloria Damasco series by Chicana writer Lucha Corpi and the graphic novel Chicanos (Trillo and Risso, 1996). Both protagonists (Gloria Damasco, a Chicana clairvoyant detective, and “poor, ugly, and a detective” Alejandrina Yolanda Jalisco) must face both the dangers of investigating criminal cases and discrimination in their professional surroundings due to their gender and ethnicity. By contrasting these texts, the essay elucidates the importance of specific cultural products, their connection to (and defiance of) canonical forms of the genre, and their rejection of generic and gender expectations.

Catharine Waugh McCullouch papers in the Mary Earhart Dillon collection, 1869-1945

Collection primarily documents McCulloch's research on women's legal status, and her work with the Illinois Equal Suffrage Association, the National American Woman Suffrage Association, and the League of Women Voters. There is also documentation of women in the legal profession, of McCulloch's friendships with the other women suffragists and lawyers, and some biographical material. The papers contain little information about her family or social life.

Oceanic ichthyology : a treatise on the deep-sea and pelagic fishes of the world, based chiefly upon the collections made by the steamers "Blake," "Albatross," and "Fishhawk" in the northwestern Atlantic, with an atlas containing 417 figures / by George Brown Goode and Tarleton H. Bean. Pub. in connection with the National Museum and the Smithsonian institution.

v.22 (1896) text

Oceanic ichthyology : a treatise on the deep-sea and pelagic fishes of the world, based chiefly upon the collections made by the steamers "Blake," "Albatross," and "Fishhawk" in the northwestern Atlantic, with an atlas containing 417 figures / by George Brown Goode and Tarleton H. Bean. Pub. in connection with the National Museum and the Smithsonian institution.

v.22 (1896) atlas

The brown-tail moth, Euproctis chrysorrhcea (L.). A report on the life history and habits of the imported brown-tail moth, together with a description of the remedies best suited for destroying it. By Charles H. Fernald ... and Archie H. Kirkland ... Pub. under the direction of the State board of agriculture by authority of the legislature.

1903

An illustrated flora of the northern United States, Canada and the British possessions, from Newfoundland to the parallel of the southern boundary of Virginia, and from the Atlantic Ocean westward to the 102d meridian, by Nathaniel Lord Britton ... and Hon. Addison Brown ...

v. 1

The brown-tail moth, Euproctis chrysorrhcea (L.). A report on the life history and habits of the imported brown-tail moth, together with a description of the remedies best suited for destroying it. By Charles H. Fernald ... and Archie H. Kirkland ... Pub. under the direction of the State board of agriculture by authority of the legislature.

1903