7,005 research outputs found
Control means for a gas turbine engine
A means is provided for developing a signal representative of the actual compressor casing temperature, a second signal representative of compressor inlet gas temperature, and a third signal representative of compressor speed. Another means is provided for receiving the gas temperature and compressor speed signals and developing a schedule output signal which is a representative of a reference casing temperature at which a predetermined compressor blade stabilized clearance is provided. A means is also provided for comparing the actual compressor casing temperature signal and the reference casing temperature signal and developing a clearance control system representative of the difference. The clearance control signal is coupled to a control valve which controls a flow of air to the compressor casing to control the clearance between the compressor blades and the compressor casing. The clearance control signal can be modified to accommodate transient characteristics. Other embodiments are disclosed
A new molecular diagnostic tool for surveying and monitoring Triops cancriformis populations
© 2017 Sellers et al. The tadpole shrimp, Triops cancriformis, is a freshwater crustacean listed as endangered in the UK and Europe living in ephemeral pools. Populations are threatened by habitat destruction due to land development for agriculture and increased urbanisation. Despite this, there is a lack of efficient methods for discovering and monitoring populations. Established macroinvertebrate monitoring methods, such as net sampling, are unsuitable given the organism's life history, that include long lived diapausing eggs, benthic habits and ephemerally active populations. Conventional hatching methods, such as sediment incubation, are both time consuming and potentially confounded by bet-hedging hatching strategies of diapausing eggs. Here we develop a new molecular diagnostic method to detect viable egg banks of T. cancriformis, and compare its performance to two conventional monitoring methods involving diapausing egg hatching. We apply this method to a collection of pond sediments from the Wildfowl & Wetlands Trust Caerlaverock National Nature Reserve, which holds one of the two remaining British populations of T. cancriformis. DNA barcoding of isolated eggs, using newly designed species-specific primers for a large region of mtDNA, was used to estimate egg viability. These estimates were compared to those obtained by the conventional methods of sediment and isolation hatching. Our method outperformed the conventional methods, revealing six ponds holding viable T. cancriformis diapausing egg banks in Caerlaverock. Additionally, designed species-specific primers for a short region of mtDNA identified degraded, inviable eggs and were used to ascertain the levels of recent mortality within an egg bank. Together with efficient sugar flotation techniques to extract eggs from sediment samples, our molecular method proved to be a faster and more powerful alternative for assessing the viability and condition of T. cancriformis diapausing egg banks
Book Review: Advanced Missiology: How to Study Missions in Credible and Useful Ways by Kenneth R. Nehrbass
Constitutional Law - First Amendment - Freedom of Speech (Bethel School District No. 403 v. Fraser)
History, Memory, and the Indian Struggle for Autonomy in the Seventeenth-Century Hudson Valley
This essay uses treaty records, council minutes, personal correspondence, and travel narratives to argue that Hudson Valley Indians seized on the 1664 English conquest of New Netherland to try to position Natives and newcomers as independent members of an extended community sharing a common past and landscape. Formulating a history emphasizing peace, preserving the memory of that past through ritual actions, and involving English colonists in processes that rested on that history, Native Americans sought to integrate the newcomers into their existing network of social relations and a physical landscape that manifested those relations. Meanwhile, English colonists seeking to secure the colony and confirm individual land titles participated in rituals, agreed to treaties, and recorded land purchases in ways that acknowledged Indians’ memories regarding lands and the communities that inhabited them. Though the project ultimately failed, the English conquest of New Netherland briefly introduced the possibility of integrating the newcomers into a larger community of diverse, autonomous peoples connected by a common history embedded in the Hudson Valley’s regional landscape
Book Review: Donald A. McGavran: A Biography of the Twentieth Century\u27s Premier Missiologist by Gary McIntosh
Southern Cavalier, Steadfast Unionist: An Ohio Poet-General\u27s Elegant Dispatches From The Field
In her well-documented introduction to wartime letters of William Haines Lytle (1826-1863), editor Ruth C. Carter characterizes Ohio\u27s poet-general as the epitome of the Southern cavalier -- vain, romantic, schooled in the social graces yet also pro-slavery, politically active, and a Douglas Democra...
Donald A. McGavran: A Biography of the Twentieth Century\u27s Premier Missiologist. By Gary McIntosh
The Union Soldier Meets the Freedman
This article documents the treatment of Freedman by the Union Army
Book Review: Church Planting in the Secular West: Learning from the European Experience by Stefan Paas
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