6,654 research outputs found

    Coke of Norfolk 1754-1842: a biography by Susanna Wade Martins [2009]

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    Susanna Wade Martins, Coke of Norfolk, 1754ā€“1842. A Biography, Woodbridge, Suffolk, The Boydell Press, 2009. xii + 218 pp. Ā£50.00. 9781843834267. This biography does Thomas Coke full justice, in style as well as in content. It is excellently illustrated with colour and monochrome plates with helpful, discursive captions and specially drawn maps and diagrams. The bibliography and index are extensive and the book has been meticulously produced. Cokeā€™s memory is well served by this first-rate piece of work

    Validation test of 125 Ah advanced design IPV nickel-hydrogen flight cells

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    An update of validation test results confirming the advanced design nickel-hydrogen cell is presented. An advanced 125 Ah individual pressure vessel (IPV) nickel-hydrogen cell was designed. The primary function of the advanced cell is to store and deliver energy for long-term, Low-Earth-Orbit (LEO) spacecraft missions. The new features of this design, which are not incorporated in state-of-the-art design cells, are: (1) use of 26 percent rather than 31 percent potassium hydroxide (KOH) electrolyte; (2) use of a patented catalyzed wall wick; (3) use of serrated-edge separators to facilitate gaseous oxygen and hydrogen flow within the cell, while still maintaining physical contact with the wall wick for electrolyte management; and (4) use of a floating rather than a fixed stack (state-of-the-art) to accommodate nickel electrode expansion due to charge/discharge cycling. The significant improvements resulting from these innovations are extended cycle life; enhanced thermal, electrolyte, and oxygen management; and accommodation of nickel electrode expansion. Six 125 Ah flight cells based on this design were fabricated by Eagle-Picher. Three of the cells contain all of the advanced features (test cells) and three are the same as the test cells except they do not have catalyst on the wall wick (control cells). All six cells are in the process of being evaluated in a LEO cycle life test at the Naval Weapons Support Center, Crane, IN, under a NASA Lewis Research Center contract. The catalyzed wall wick cells have been cycled for over 19000 cycles with no cell failures in the continuing test. Two of the noncatalyzed wall wick cells failed (cycles 9588 and 13,900)

    Effect of KOH concentration on LEO cycle life of IPV nickel-hydrogen flight cells-update 2

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    An update of validation test results confirming the breakthrough in low earth orbit (LEO) cycle life of nickel-hydrogen cells containing 26 percent KOH electrolyte is presented. A breakthrough in the LEO cycle life of individual pressure vessel (IPV nickel-hydrogen cells has been previously reported. The cycle life of boiler plate cells containing 26 percent potassium hydroxide (KOH) electrolyte was about 40 000 LEO cycles compared to 3500 cycles for cells containing 31 percent KOH. This test was conducted at Hughes Aircraft Company under a NASA Lewis contract. The purpose was to investigate the effect of KOH concentration on cycle life. The cycle regime was a stressful accelerated LEO, which consisted of a 27.5 min charge followed by a 17.5 min discharge (2x normal rate). The depth of discharge (DOD) was 80 percent. The cell temperature was maintained at 23 C. The boiler plate test results are in the process of being validated using flight hardware and real time LEO test at the Naval Weapons Support Center (NWSC), Crane, Indiana under a NASA Lewis Contract. Six 48 Ah Hughes recirculation design IPV nickel-hydrogen flight battery cells are being evaluated. Three of the cells contain 26 percent KOH (test cells), and three contain 31 percent KOH (control cells). They are undergoing real time LEO cycle life testing. The cycle regime is a 90-min LEO orbit consisting of a 54-min charge followed by a 36-min discharge. The depth-of-discharge is 80 percent. The cell temperature is maintained at 10 C. The three 31 percent KOH cells failed (cycles 3729, 4165, and 11355). One of the 26 percent KOH cells failed at cycle 15314. The other two 26 percent KOH cells were cycled for over 16600 cycles during the continuing test

    Effect of KOH concentration on LEO cycle life of IPV nickel-hydrogen flight battery cells

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    A breakthrough in low earth orbit (LEO) cycle life of individual pressure vessel (IPV) nickel hydrogen battery cells was reported. The cycle life of boiler plate cells containing 26 percent potassium hydroxide (KOH) electrolyte was about 40,000 LEO cycles compared to 3500 cycles for cells containing 31 percent KOH. The effect of KOH concentration on cycle life was studied. The cycle regime was a stressful accelerated LEO, which consisted of a 27.5 min charge followed by a 17.5 min charge (2 x normal rate). The depth of discharge (DOD) was 80 percent. The cell temperature was maintained at 23 C. The next step is to validate these results using flight hardware and a real time LEO test. NASA Lewis has a contract with the Naval Weapons Support Center (NWSC), Crane, Indiana, to validate the boiler plate test results. Six 48 A-hr Hughes recirculation design IPV nickel-hydrogen flight battery cells are being evaluated. Three of the cells contain 26 percent KOH (test cells) and three contain 31 percent KOH (control cells). They are undergoing real time LEO cycle life testing. The cycle regime is a 90-min LEO orbit consisting of a 54-min charge followed by a 36-min discharge. The depth-of-discharge is 80 percent. The cell temperature is maintained at 10 C. The cells were cycled for over 8000 cycles in the continuing test. There were no failures for the cells containing 26 percent KOH. There was two failures, however, for the cells containing 31 percent KOH

    Validation test of advanced technology for IPV nickel-hydrogen flight cells: Update

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    Individual pressure vessel (IPV) nickel-hydrogen technology was advanced at NASA Lewis and under Lewis contracts with the intention of improving cycle life and performance. One advancement was to use 26 percent potassium hydroxide (KOH) electrolyte to improve cycle life. Another advancement was to modify the state-of-the-art cell design to eliminate identified failure modes. The modified design is referred to as the advanced design. A breakthrough in the low-earth-orbit (LEO) cycle life of IPV nickel-hydrogen cells has been previously reported. The cycle life of boiler plate cells containing 26 percent KOH electrolyte was about 40,000 LEO cycles compared to 3,500 cycles for cells containing 31 percent KOH. The boiler plate test results are in the process of being validated using flight hardware and real time LEO testing at the Naval Weapons Support Center (NWSC), Crane, Indiana under a NASA Lewis Contract. An advanced 125 Ah IPV nickel-hydrogen cell was designed. The primary function of the advanced cell is to store and deliver energy for long-term, LEO spacecraft missions. The new features of this design are: (1) use of 26 percent rather than 31 percent KOH electrolyte; (2) use of a patented catalyzed wall wick; (3) use of serrated-edge separators to facilitate gaseous oxygen and hydrogen flow within the cell, while still maintaining physical contact with the wall wick for electrolyte management; and (4) use of a floating rather than a fixed stack (state-of-the-art) to accommodate nickel electrode expansion due to charge/discharge cycling. The significant improvements resulting from these innovations are: extended cycle life; enhanced thermal, electrolyte, and oxygen management; and accommodation of nickel electrode expansion. The advanced cell design is in the process of being validated using real time LEO cycle life testing of NWSC, Crane, Indiana. An update of validation test results confirming this technology is presented

    Effect of LEO cycling on 125 Ah advanced design IPV nickel-hydrogen flight cells. An update

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    Validation testing of the NASA Lewis 125 Ah advanced design individual pressure vessel (IPV) nickel-hydrogen flight cells was conducted. Work consisted of characterization, storage, and cycle life testing. There was no capacity degradation after 52 days of storage with the cells in the discharged state, an open circuit, 0 C, and a hydrogen pressure of 14.5 psia. The catalyzed wall wick cells were cycled for over 11,000 cycles with no cell failures in the continuing test. One of the noncatalyzed wall wick cells failed

    Beyond teacher transmission and Googling information to more creative language learning

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    As information is readily available online, students can Google and Google Translate perhaps challenging a teacherā€™s classroom role and language awareness. The safety of being a transmitter of knowledge and instructor may be threatened and classrooms could become fossilized as the instant nature of information grows. This paper will argue that by facilitating modern language learning we could also stimulate questioning. Tasks may need to include appropriate on line searching and a creative inquiry approach to using language. This suggests reworking teacher dominance into a facilitatorā€™s role. Digital natives and the Facebook/Instagram/Snapchat generation may want a culture of learning which embraces information flows, while providing tools for English language learning and use in the modern era. Suggestions for engaging learners with contemporary techniques will be shared, even for classrooms in which there is not readily available connectivity

    Learning from teacher educators: Reflecting on the certainty of teaching 'recipes'

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    Change towards an interactive classroom is often blocked by lack of acceptance of new techniques which require changes in a teachersā€™ role away from step-by-step sequences or `recipesā€™. Such ā€˜recipesā€™ while useful for novice teachers may not work in all contexts. This paper describes how culturally based perceptions of a teacherā€™s role impact on acceptance of classroom innovation and suggests teacher reflective practice. Building acceptance of differing methodologies in the early phases when first impressions count is therefore linked to reflection and lessons from in service teacher education. This paper uses rural in-service doctoral data and links research findings to classroom practice, focused on developing cross cultural acceptance of change. Techniques are suggested for bridging cultural gaps with reflective tools. These techniques drawn for research are presented by examining the roles we play as either teachers or teacher educators who wish to ā€˜cook upā€™ learning in interactive classrooms

    Deconstructing aspects of native speakerism: Reflections from in-service teacher education

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    In many Asian contexts, issues of who teaches and educates teachers in English Language Teaching remain challenging with status accorded to socalled ā€˜native speakersā€™. Issues still remain after two decades of research calling for deconstruction of the native speaker fallacy. Drawing on critiques of the concept, as well as teacher education research, this paper suggests ways to deconstruct the maze of native speakerism. Recent Malaysian in- service training research shows that positioning and modeling can override the origin of the teacher educator, namely a so-called native speaker background. Descriptions of techniques to help deconstruct native speakerism at the interactional level are derived from teacher educator reflection on data. Possibilities for countering native speakerism are suggested through descriptions of how teacher educators may model and use humour to address perceptions of hierarchy. With the growing use of English as an additional language, research into who teaches or educates teachers could also address the challenges of hidden professional racism sustained by factors such as so-called Standard English. Practical approaches from teacher educator reflections on their interaction with Malaysian teachers suggest ways to reconstruct aspects of native speakerism

    [Book Review] Motivation in the Language Classroom / Willy A Renandya. Alexandria, VA: TESOL Press, 2014

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