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Tritium Content of Clay Minerals
- Thomas M. Marston, W. T. Parry, John R. Bowman, D. Kip Solomon
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- Journal:
- Clays and Clay Minerals / Volume 60 / Issue 2 / April 2012
- Published online by Cambridge University Press:
- 01 January 2024, pp. 186-199
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The presence, percentage, origins, and rate of formation of clay minerals have been important components in studies involving the geochemical and structural composition of waste-rock piles. The objective of the present study was to investigate the use of tritium as an indicator of the origin of clay minerals within such piles. Tritium values in pore water, interlayer water, and structural hydroxyl sites of clay minerals were examined to evaluate the origins of clay minerals within waste-rock piles located near Questa, New Mexico. Five clay minerals were identified: kaolinite, chlorite, illite, smectite, and mixedlayer illite-smectite, along with the hydrous sulfate minerals gypsum and jarosite. Analysis of waters derived from clay minerals was achieved by thermal reaction of dry-sieved bulk material obtained from the Questa site. In all Questa samples, the low-temperature water derived from pore-water and interlayer sites, as well as the intermediate-temperature water derived from interlayer cation sites occupied by hydronium and structural hydroxyl ions, show tritium values at or near modern levels for precipitation. Pore water and interlayer water ranged from 5.31 to 12.19 tritium units (TU) and interlayer hydronium and structurally derived water ranged from 3.92 to 7.93 TU. Tritium levels for local precipitation ranged from ~4 to 8 TU. One tritium unit (TU) represents one molecule of 3H1HO in 1018 molecules of 1H1HO. The elevated levels of tritium in structural sites can be accounted for by thermal incorporation of significant amounts of hydronium ions in interlayer cation sites for illite and mixed-layer clays, both common at the Questa site. In low-pH environments, such as those found within Questa waste-rock piles (typically pH ~3), the hydronium ion is an abundant species in the rock-pile pore-water system.
The trouble with cover crops: Farmers’ experiences with overcoming barriers to adoption
- Gabrielle E. Roesch-McNally, Andrea D. Basche, J.G. Arbuckle, John C. Tyndall, Fernando E. Miguez, Troy Bowman, Rebecca Clay
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- Journal:
- Renewable Agriculture and Food Systems / Volume 33 / Issue 4 / August 2018
- Published online by Cambridge University Press:
- 13 March 2017, pp. 322-333
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Cover crops are known to promote many aspects of soil and water quality, yet estimates find that in 2012 only 2.3% of the total agricultural lands in the Midwestern USA were using cover crops. Focus groups were conducted across the Corn Belt state of Iowa to better understand how farmers confront barriers to cover crop adoption in highly intensive agricultural production systems. Although much prior research has focused on analyzing factors that help predict cover crop use on farms, there is limited research on how farmers navigate and overcome field-level (e.g. proper planting of a cover crop) and structural barriers (e.g. market forces) associated with the use of cover crops. The results from the analysis of these conversations suggest that there is a complex dialectical relationship between farmers' individual management decisions and the broader agricultural context in the region that constrains their decisions. Farmers in these focus groups shared how they navigate complex management decisions within a generally homogenized agricultural and economic landscape that makes cover crop integration challenging. Many who joined the focus groups have found ways to overcome barriers and successfully integrate cover crops into their cropping systems. This is illustrated through farmers' descriptions of their ‘whole system’ approach to cover crops management, where they described how they prioritize the success of their cover crops by focusing on multiple aspects of management, including changes they have made to nutrient application and modifications to equipment. These producers also engage with farmer networks to gain strategies for overcoming management challenges associated with cover crops. Although many participants had successfully planted cover crops, they tended to believe that greater economic incentives and/or more diverse crop and livestock markets would be needed to spur more widespread adoption of the practice. Our results further illustrate how structural and field-level barriers constrain individual actions, as it is not simply the basic agronomic considerations (such as seeding and terminating cover crops) that pose a challenge to their use, but also the broader economic and market drivers that exist in agriculturally intensive systems. Our study provides evidence that reducing structural barriers to adoption may be necessary to increase the use of this conservation practice to reduce environmental impacts associated with intensive agricultural production.
Mandalacystis, a new rhipidocystid eocrinoid from the Whiterockian Stage (Ordovician) in Oklahoma and Nevada
- Ronald D. Lewis, James Sprinkle, J. Bowman Bailey, John Moffit, Ronald L. Parsley
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- Journal of Paleontology / Volume 61 / Issue 6 / November 1987
- Published online by Cambridge University Press:
- 14 July 2015, pp. 1222-1235
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Mandalacystis dockeryi n. gen. and sp. is known from seven complete or nearly complete thecae, six partial thecae, and numerous separate plates from the Oil Creek Formation in south-central Oklahoma, and a single thecal plate from the Antelope Valley Limestone in Nevada. Details of skeletal microstructure (stereom) are well preserved, permitting scanning electron microscopy for the first time in the Eocrinoidea, and demonstrating that plate thickness on thecal faces is only 60–70 μm. Mandalacystis is characterized by labyrinthine ridges on both faces of the theca, relatively short brachioles, and a normal stem with holdfast (at least in juvenile stages). Based on the normal biserial arrangement of brachiolar plates in the brachioles and the possession of a normal stem, Mandalacystis appears to be one of the most primitive rhipidocystids, closely related to Petalocystites.
Mandalacystis dockeryi lived in a storm-dominated, shallow-water offshore habitat on patches of skeletal debris surrounded by soft, terrigenous mud. This setting may have been conducive to the transition from an erect, attached mode of life to the prone, unattached lifestyle of later rhipidocystids.
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- By Masoud Azodi, Patricia Baetens, Steven Bayer, Joel Bernstein, Jonathan D. Black, Christophe Blockeel, Carolien M. Boomsma, Birgit Borgström, Mark Bowman, Nicholas Brook, Elisabeth Carlsen, Peter Carne, Ying Cheong, Jen-Ruei Chen, Erin Clark, S. Alberto Dávila Garza, Sunita De Sousa, Michel De Vos, Leo Doherty, Patricio Donoso, Cindy M. P. Duke, Human M. Fatemi, Alison Fernbach, Juan A. Garcia-Velasco, Elizabeth S. Ginsburg, Dorothy A. Greenfeld, William M. Hague, Daniel Hajioff, Tristan Hardy, Catherine Henry, Outi Hovatta, John Hutton, Gordana Ivanovic, Sameer Jatkar, Shilpa Jesudason, Theo Joseph, Amanda Kallen, Sonal Karia, Bala Karunakaran, Jenneke C. Kasius, Ben Kroon, Dimitra Kyrou, Robert Lahoud, Jennifer M Levine, Inge Liebaers, Shane T. Lipskind, Derek Lok, Nick S. Macklon, Manveen (Manny) Mangat, Tom P. Manolitsas, S. McDowell, Cherise Mooy, Mark R. Morton, Andrew Murray, Robert J. Norman, Sara Ornaghi, Israel Ortega, Michael J. Paidas, Evaggelos Papanikolaou, Pasquale Patrizio, Sofie Piessens, Biljana Popovic Todorovic, Luk Rombauts, Katrina Rowan, Denny Sakkas, P. Sanhueza, Kirsten Tryde Schmidt, Mark Teoh, Hammed A. Tijani, Jelena Todorovic, Saioa Torrealday, Herman Tournaye, Geoffrey Trew, W. Verpoest, Veerle Vloeberghs, A. Yazdani
- Edited by Nick S. Macklon, University of Southampton, Human M. Fatemi, Robert J. Norman, University of Adelaide, Pasquale Patrizio
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- Case Studies in Assisted Reproduction
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- 05 February 2015
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- 22 January 2015, pp ix-xiv
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The Murchison Widefield Array Commissioning Survey: A Low-Frequency Catalogue of 14 110 Compact Radio Sources over 6 100 Square Degrees
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- Natasha Hurley-Walker, John Morgan, Randall B. Wayth, Paul J. Hancock, Martin E. Bell, Gianni Bernardi, Ramesh Bhat, Frank Briggs, Avinash A. Deshpande, Aaron Ewall-Wice, Lu Feng, Bryna J. Hazelton, Luke Hindson, Daniel C. Jacobs, David L. Kaplan, Nadia Kudryavtseva, Emil Lenc, Benjamin McKinley, Daniel Mitchell, Bart Pindor, Pietro Procopio, Divya Oberoi, André Offringa, Stephen Ord, Jennifer Riding, Judd D. Bowman, Roger Cappallo, Brian Corey, David Emrich, B. M. Gaensler, Robert Goeke, Lincoln Greenhill, Jacqueline Hewitt, Melanie Johnston-Hollitt, Justin Kasper, Eric Kratzenberg, Colin Lonsdale, Mervyn Lynch, Russell McWhirter, Miguel F. Morales, Edward Morgan, Thiagaraj Prabu, Alan Rogers, Anish Roshi, Udaya Shankar, K. Srivani, Ravi Subrahmanyan, Steven Tingay, Mark Waterson, Rachel Webster, Alan Whitney, Andrew Williams, Chris Williams
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- Publications of the Astronomical Society of Australia / Volume 31 / 2014
- Published online by Cambridge University Press:
- 14 November 2014, e045
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We present the results of an approximately 6 100 deg2 104–196 MHz radio sky survey performed with the Murchison Widefield Array during instrument commissioning between 2012 September and 2012 December: the MWACS. The data were taken as meridian drift scans with two different 32-antenna sub-arrays that were available during the commissioning period. The survey covers approximately 20.5 h < RA < 8.5 h, − 58° < Dec < −14°over three frequency bands centred on 119, 150 and 180 MHz, with image resolutions of 6–3 arcmin. The catalogue has 3 arcmin angular resolution and a typical noise level of 40 mJy beam− 1, with reduced sensitivity near the field boundaries and bright sources. We describe the data reduction strategy, based upon mosaicked snapshots, flux density calibration, and source-finding method. We present a catalogue of flux density and spectral index measurements for 14 110 sources, extracted from the mosaic, 1 247 of which are sub-components of complexes of sources.
Science with the Murchison Widefield Array
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- Judd D. Bowman, Iver Cairns, David L. Kaplan, Tara Murphy, Divya Oberoi, Lister Staveley-Smith, Wayne Arcus, David G. Barnes, Gianni Bernardi, Frank H. Briggs, Shea Brown, John D. Bunton, Adam J. Burgasser, Roger J. Cappallo, Shami Chatterjee, Brian E. Corey, Anthea Coster, Avinash Deshpande, Ludi deSouza, David Emrich, Philip Erickson, Robert F. Goeke, B. M. Gaensler, Lincoln J. Greenhill, Lisa Harvey-Smith, Bryna J. Hazelton, David Herne, Jacqueline N. Hewitt, Melanie Johnston-Hollitt, Justin C. Kasper, Barton B. Kincaid, Ronald Koenig, Eric Kratzenberg, Colin J. Lonsdale, Mervyn J. Lynch, Lynn D. Matthews, S. Russell McWhirter, Daniel A. Mitchell, Miguel F. Morales, Edward H. Morgan, Stephen M. Ord, Joseph Pathikulangara, Thiagaraj Prabu, Ronald A. Remillard, Timothy Robishaw, Alan E. E. Rogers, Anish A. Roshi, Joseph E. Salah, Robert J. Sault, N. Udaya Shankar, K. S. Srivani, Jamie B. Stevens, Ravi Subrahmanyan, Steven J. Tingay, Randall B. Wayth, Mark Waterson, Rachel L. Webster, Alan R. Whitney, Andrew J. Williams, Christopher L. Williams, J. Stuart B. Wyithe
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- Publications of the Astronomical Society of Australia / Volume 30 / 2013
- Published online by Cambridge University Press:
- 16 April 2013, e031
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Significant new opportunities for astrophysics and cosmology have been identified at low radio frequencies. The Murchison Widefield Array is the first telescope in the southern hemisphere designed specifically to explore the low-frequency astronomical sky between 80 and 300 MHz with arcminute angular resolution and high survey efficiency. The telescope will enable new advances along four key science themes, including searching for redshifted 21-cm emission from the EoR in the early Universe; Galactic and extragalactic all-sky southern hemisphere surveys; time-domain astrophysics; and solar, heliospheric, and ionospheric science and space weather. The Murchison Widefield Array is located in Western Australia at the site of the planned Square Kilometre Array (SKA) low-band telescope and is the only low-frequency SKA precursor facility. In this paper, we review the performance properties of the Murchison Widefield Array and describe its primary scientific objectives.
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- By Rose Teteki Abbey, K. C. Abraham, David Tuesday Adamo, LeRoy H. Aden, Efrain Agosto, Victor Aguilan, Gillian T. W. Ahlgren, Charanjit Kaur AjitSingh, Dorothy B E A Akoto, Giuseppe Alberigo, Daniel E. Albrecht, Ruth Albrecht, Daniel O. Aleshire, Urs Altermatt, Anand Amaladass, Michael Amaladoss, James N. Amanze, Lesley G. Anderson, Thomas C. Anderson, Victor Anderson, Hope S. Antone, María Pilar Aquino, Paula Arai, Victorio Araya Guillén, S. Wesley Ariarajah, Ellen T. Armour, Brett Gregory Armstrong, Atsuhiro Asano, Naim Stifan Ateek, Mahmoud Ayoub, John Alembillah Azumah, Mercedes L. García Bachmann, Irena Backus, J. Wayne Baker, Mieke Bal, Lewis V. Baldwin, William Barbieri, António Barbosa da Silva, David Basinger, Bolaji Olukemi Bateye, Oswald Bayer, Daniel H. Bays, Rosalie Beck, Nancy Elizabeth Bedford, Guy-Thomas Bedouelle, Chorbishop Seely Beggiani, Wolfgang Behringer, Christopher M. Bellitto, Byard Bennett, Harold V. Bennett, Teresa Berger, Miguel A. Bernad, Henley Bernard, Alan E. Bernstein, Jon L. Berquist, Johannes Beutler, Ana María Bidegain, Matthew P. Binkewicz, Jennifer Bird, Joseph Blenkinsopp, Dmytro Bondarenko, Paulo Bonfatti, Riet en Pim Bons-Storm, Jessica A. Boon, Marcus J. Borg, Mark Bosco, Peter C. Bouteneff, François Bovon, William D. Bowman, Paul S. Boyer, David Brakke, Richard E. Brantley, Marcus Braybrooke, Ian Breward, Ênio José da Costa Brito, Jewel Spears Brooker, Johannes Brosseder, Nicholas Canfield Read Brown, Robert F. Brown, Pamela K. Brubaker, Walter Brueggemann, Bishop Colin O. Buchanan, Stanley M. Burgess, Amy Nelson Burnett, J. Patout Burns, David B. Burrell, David Buttrick, James P. Byrd, Lavinia Byrne, Gerado Caetano, Marcos Caldas, Alkiviadis Calivas, William J. Callahan, Salvatore Calomino, Euan K. Cameron, William S. Campbell, Marcelo Ayres Camurça, Daniel F. Caner, Paul E. Capetz, Carlos F. Cardoza-Orlandi, Patrick W. Carey, Barbara Carvill, Hal Cauthron, Subhadra Mitra Channa, Mark D. Chapman, James H. Charlesworth, Kenneth R. Chase, Chen Zemin, Luciano Chianeque, Philip Chia Phin Yin, Francisca H. Chimhanda, Daniel Chiquete, John T. Chirban, Soobin Choi, Robert Choquette, Mita Choudhury, Gerald Christianson, John Chryssavgis, Sejong Chun, Esther Chung-Kim, Charles M. A. Clark, Elizabeth A. Clark, Sathianathan Clarke, Fred Cloud, John B. Cobb, W. Owen Cole, John A Coleman, John J. Collins, Sylvia Collins-Mayo, Paul K. Conkin, Beth A. Conklin, Sean Connolly, Demetrios J. Constantelos, Michael A. Conway, Paula M. Cooey, Austin Cooper, Michael L. Cooper-White, Pamela Cooper-White, L. William Countryman, Sérgio Coutinho, Pamela Couture, Shannon Craigo-Snell, James L. Crenshaw, David Crowner, Humberto Horacio Cucchetti, Lawrence S. Cunningham, Elizabeth Mason Currier, Emmanuel Cutrone, Mary L. Daniel, David D. Daniels, Robert Darden, Rolf Darge, Isaiah Dau, Jeffry C. Davis, Jane Dawson, Valentin Dedji, John W. de Gruchy, Paul DeHart, Wendy J. Deichmann Edwards, Miguel A. De La Torre, George E. Demacopoulos, Thomas de Mayo, Leah DeVun, Beatriz de Vasconcellos Dias, Dennis C. Dickerson, John M. Dillon, Luis Miguel Donatello, Igor Dorfmann-Lazarev, Susanna Drake, Jonathan A. Draper, N. Dreher Martin, Otto Dreydoppel, Angelyn Dries, A. J. Droge, Francis X. D'Sa, Marilyn Dunn, Nicole Wilkinson Duran, Rifaat Ebied, Mark J. Edwards, William H. Edwards, Leonard H. Ehrlich, Nancy L. Eiesland, Martin Elbel, J. Harold Ellens, Stephen Ellingson, Marvin M. Ellison, Robert Ellsberg, Jean Bethke Elshtain, Eldon Jay Epp, Peter C. Erb, Tassilo Erhardt, Maria Erling, Noel Leo Erskine, Gillian R. Evans, Virginia Fabella, Michael A. Fahey, Edward Farley, Margaret A. Farley, Wendy Farley, Robert Fastiggi, Seena Fazel, Duncan S. Ferguson, Helwar Figueroa, Paul Corby Finney, Kyriaki Karidoyanes FitzGerald, Thomas E. FitzGerald, John R. Fitzmier, Marie Therese Flanagan, Sabina Flanagan, Claude Flipo, Ronald B. Flowers, Carole Fontaine, David Ford, Mary Ford, Stephanie A. Ford, Jim Forest, William Franke, Robert M. Franklin, Ruth Franzén, Edward H. Friedman, Samuel Frouisou, Lorelei F. Fuchs, Jojo M. Fung, Inger Furseth, Richard R. Gaillardetz, Brandon Gallaher, China Galland, Mark Galli, Ismael García, Tharscisse Gatwa, Jean-Marie Gaudeul, Luis María Gavilanes del Castillo, Pavel L. Gavrilyuk, Volney P. Gay, Metropolitan Athanasios Geevargis, Kondothra M. George, Mary Gerhart, Simon Gikandi, Maurice Gilbert, Michael J. Gillgannon, Verónica Giménez Beliveau, Terryl Givens, Beth Glazier-McDonald, Philip Gleason, Menghun Goh, Brian Golding, Bishop Hilario M. Gomez, Michelle A. Gonzalez, Donald K. Gorrell, Roy Gottfried, Tamara Grdzelidze, Joel B. Green, Niels Henrik Gregersen, Cristina Grenholm, Herbert Griffiths, Eric W. Gritsch, Erich S. Gruen, Christoffer H. Grundmann, Paul H. Gundani, Jon P. Gunnemann, Petre Guran, Vidar L. Haanes, Jeremiah M. Hackett, Getatchew Haile, Douglas John Hall, Nicholas Hammond, Daphne Hampson, Jehu J. Hanciles, Barry Hankins, Jennifer Haraguchi, Stanley S. Harakas, Anthony John Harding, Conrad L. Harkins, J. William Harmless, Marjory Harper, Amir Harrak, Joel F. Harrington, Mark W. Harris, Susan Ashbrook Harvey, Van A. Harvey, R. Chris Hassel, Jione Havea, Daniel Hawk, Diana L. Hayes, Leslie Hayes, Priscilla Hayner, S. Mark Heim, Simo Heininen, Richard P. Heitzenrater, Eila Helander, David Hempton, Scott H. Hendrix, Jan-Olav Henriksen, Gina Hens-Piazza, Carter Heyward, Nicholas J. Higham, David Hilliard, Norman A. Hjelm, Peter C. Hodgson, Arthur Holder, M. Jan Holton, Dwight N. Hopkins, Ronnie Po-chia Hsia, Po-Ho Huang, James Hudnut-Beumler, Jennifer S. Hughes, Leonard M. Hummel, Mary E. Hunt, Laennec Hurbon, Mark Hutchinson, Susan E. Hylen, Mary Beth Ingham, H. Larry Ingle, Dale T. Irvin, Jon Isaak, Paul John Isaak, Ada María Isasi-Díaz, Hans Raun Iversen, Margaret C. Jacob, Arthur James, Maria Jansdotter-Samuelsson, David Jasper, Werner G. Jeanrond, Renée Jeffery, David Lyle Jeffrey, Theodore W. Jennings, David H. Jensen, Robin Margaret Jensen, David Jobling, Dale A. Johnson, Elizabeth A. Johnson, Maxwell E. Johnson, Sarah Johnson, Mark D. Johnston, F. Stanley Jones, James William Jones, John R. Jones, Alissa Jones Nelson, Inge Jonsson, Jan Joosten, Elizabeth Judd, Mulambya Peggy Kabonde, Robert Kaggwa, Sylvester Kahakwa, Isaac Kalimi, Ogbu U. Kalu, Eunice Kamaara, Wayne C. Kannaday, Musimbi Kanyoro, Veli-Matti Kärkkäinen, Frank Kaufmann, Léon Nguapitshi Kayongo, Richard Kearney, Alice A. Keefe, Ralph Keen, Catherine Keller, Anthony J. Kelly, Karen Kennelly, Kathi Lynn Kern, Fergus Kerr, Edward Kessler, George Kilcourse, Heup Young Kim, Kim Sung-Hae, Kim Yong-Bock, Kim Yung Suk, Richard King, Thomas M. King, Robert M. Kingdon, Ross Kinsler, Hans G. Kippenberg, Cheryl A. Kirk-Duggan, Clifton Kirkpatrick, Leonid Kishkovsky, Nadieszda Kizenko, Jeffrey Klaiber, Hans-Josef Klauck, Sidney Knight, Samuel Kobia, Robert Kolb, Karla Ann Koll, Heikki Kotila, Donald Kraybill, Philip D. W. Krey, Yves Krumenacker, Jeffrey Kah-Jin Kuan, Simanga R. Kumalo, Peter Kuzmic, Simon Shui-Man Kwan, Kwok Pui-lan, André LaCocque, Stephen E. Lahey, John Tsz Pang Lai, Emiel Lamberts, Armando Lampe, Craig Lampe, Beverly J. Lanzetta, Eve LaPlante, Lizette Larson-Miller, Ariel Bybee Laughton, Leonard Lawlor, Bentley Layton, Robin A. Leaver, Karen Lebacqz, Archie Chi Chung Lee, Marilyn J. Legge, Hervé LeGrand, D. L. LeMahieu, Raymond Lemieux, Bill J. Leonard, Ellen M. Leonard, Outi Leppä, Jean Lesaulnier, Nantawan Boonprasat Lewis, Henrietta Leyser, Alexei Lidov, Bernard Lightman, Paul Chang-Ha Lim, Carter Lindberg, Mark R. Lindsay, James R. Linville, James C. Livingston, Ann Loades, David Loades, Jean-Claude Loba-Mkole, Lo Lung Kwong, Wati Longchar, Eleazar López, David W. Lotz, Andrew Louth, Robin W. Lovin, William Luis, Frank D. Macchia, Diarmaid N. J. MacCulloch, Kirk R. MacGregor, Marjory A. MacLean, Donald MacLeod, Tomas S. Maddela, Inge Mager, Laurenti Magesa, David G. Maillu, Fortunato Mallimaci, Philip Mamalakis, Kä Mana, Ukachukwu Chris Manus, Herbert Robinson Marbury, Reuel Norman Marigza, Jacqueline Mariña, Antti Marjanen, Luiz C. L. Marques, Madipoane Masenya (ngwan'a Mphahlele), Caleb J. D. Maskell, Steve Mason, Thomas Massaro, Fernando Matamoros Ponce, András Máté-Tóth, Odair Pedroso Mateus, Dinis Matsolo, Fumitaka Matsuoka, John D'Arcy May, Yelena Mazour-Matusevich, Theodore Mbazumutima, John S. McClure, Christian McConnell, Lee Martin McDonald, Gary B. McGee, Thomas McGowan, Alister E. McGrath, Richard J. McGregor, John A. McGuckin, Maud Burnett McInerney, Elsie Anne McKee, Mary B. McKinley, James F. McMillan, Ernan McMullin, Kathleen E. McVey, M. Douglas Meeks, Monica Jyotsna Melanchthon, Ilie Melniciuc-Puica, Everett Mendoza, Raymond A. Mentzer, William W. Menzies, Ina Merdjanova, Franziska Metzger, Constant J. Mews, Marvin Meyer, Carol Meyers, Vasile Mihoc, Gunner Bjerg Mikkelsen, Maria Inêz de Castro Millen, Clyde Lee Miller, Bonnie J. Miller-McLemore, Alexander Mirkovic, Paul Misner, Nozomu Miyahira, R. W. L. Moberly, Gerald Moede, Aloo Osotsi Mojola, Sunanda Mongia, Rebeca Montemayor, James Moore, Roger E. Moore, Craig E. Morrison O.Carm, Jeffry H. Morrison, Keith Morrison, Wilson J. Moses, Tefetso Henry Mothibe, Mokgethi Motlhabi, Fulata Moyo, Henry Mugabe, Jesse Ndwiga Kanyua Mugambi, Peggy Mulambya-Kabonde, Robert Bruce Mullin, Pamela Mullins Reaves, Saskia Murk Jansen, Heleen L. Murre-Van den Berg, Augustine Musopole, Isaac M. T. Mwase, Philomena Mwaura, Cecilia Nahnfeldt, Anne Nasimiyu Wasike, Carmiña Navia Velasco, Thulani Ndlazi, Alexander Negrov, James B. Nelson, David G. Newcombe, Carol Newsom, Helen J. Nicholson, George W. E. Nickelsburg, Tatyana Nikolskaya, Damayanthi M. A. Niles, Bertil Nilsson, Nyambura Njoroge, Fidelis Nkomazana, Mary Beth Norton, Christian Nottmeier, Sonene Nyawo, Anthère Nzabatsinda, Edward T. Oakes, Gerald O'Collins, Daniel O'Connell, David W. Odell-Scott, Mercy Amba Oduyoye, Kathleen O'Grady, Oyeronke Olajubu, Thomas O'Loughlin, Dennis T. Olson, J. Steven O'Malley, Cephas N. Omenyo, Muriel Orevillo-Montenegro, César Augusto Ornellas Ramos, Agbonkhianmeghe E. Orobator, Kenan B. Osborne, Carolyn Osiek, Javier Otaola Montagne, Douglas F. Ottati, Anna May Say Pa, Irina Paert, Jerry G. Pankhurst, Aristotle Papanikolaou, Samuele F. Pardini, Stefano Parenti, Peter Paris, Sung Bae Park, Cristián G. Parker, Raquel Pastor, Joseph Pathrapankal, Daniel Patte, W. Brown Patterson, Clive Pearson, Keith F. Pecklers, Nancy Cardoso Pereira, David Horace Perkins, Pheme Perkins, Edward N. Peters, Rebecca Todd Peters, Bishop Yeznik Petrossian, Raymond Pfister, Peter C. Phan, Isabel Apawo Phiri, William S. F. Pickering, Derrick G. Pitard, William Elvis Plata, Zlatko Plese, John Plummer, James Newton Poling, Ronald Popivchak, Andrew Porter, Ute Possekel, James M. Powell, Enos Das Pradhan, Devadasan Premnath, Jaime Adrían Prieto Valladares, Anne Primavesi, Randall Prior, María Alicia Puente Lutteroth, Eduardo Guzmão Quadros, Albert Rabil, Laurent William Ramambason, Apolonio M. Ranche, Vololona Randriamanantena Andriamitandrina, Lawrence R. Rast, Paul L. Redditt, Adele Reinhartz, Rolf Rendtorff, Pål Repstad, James N. Rhodes, John K. Riches, Joerg Rieger, Sharon H. Ringe, Sandra Rios, Tyler Roberts, David M. Robinson, James M. Robinson, Joanne Maguire Robinson, Richard A. H. Robinson, Roy R. Robson, Jack B. Rogers, Maria Roginska, Sidney Rooy, Rev. Garnett Roper, Maria José Fontelas Rosado-Nunes, Andrew C. Ross, Stefan Rossbach, François Rossier, John D. Roth, John K. Roth, Phillip Rothwell, Richard E. Rubenstein, Rosemary Radford Ruether, Markku Ruotsila, John E. Rybolt, Risto Saarinen, John Saillant, Juan Sanchez, Wagner Lopes Sanchez, Hugo N. Santos, Gerhard Sauter, Gloria L. Schaab, Sandra M. Schneiders, Quentin J. Schultze, Fernando F. Segovia, Turid Karlsen Seim, Carsten Selch Jensen, Alan P. F. Sell, Frank C. Senn, Kent Davis Sensenig, Damían Setton, Bal Krishna Sharma, Carolyn J. Sharp, Thomas Sheehan, N. Gerald Shenk, Christian Sheppard, Charles Sherlock, Tabona Shoko, Walter B. Shurden, Marguerite Shuster, B. Mark Sietsema, Batara Sihombing, Neil Silberman, Clodomiro Siller, Samuel Silva-Gotay, Heikki Silvet, John K. Simmons, Hagith Sivan, James C. Skedros, Abraham Smith, Ashley A. Smith, Ted A. Smith, Daud Soesilo, Pia Søltoft, Choan-Seng (C. S.) Song, Kathryn Spink, Bryan Spinks, Eric O. Springsted, Nicolas Standaert, Brian Stanley, Glen H. Stassen, Karel Steenbrink, Stephen J. Stein, Andrea Sterk, Gregory E. Sterling, Columba Stewart, Jacques Stewart, Robert B. Stewart, Cynthia Stokes Brown, Ken Stone, Anne Stott, Elizabeth Stuart, Monya Stubbs, Marjorie Hewitt Suchocki, David Kwang-sun Suh, Scott W. Sunquist, Keith Suter, Douglas Sweeney, Charles H. Talbert, Shawqi N. Talia, Elsa Tamez, Joseph B. Tamney, Jonathan Y. Tan, Yak-Hwee Tan, Kathryn Tanner, Feiya Tao, Elizabeth S. Tapia, Aquiline Tarimo, Claire Taylor, Mark Lewis Taylor, Bishop Abba Samuel Wolde Tekestebirhan, Eugene TeSelle, M. Thomas Thangaraj, David R. Thomas, Andrew Thornley, Scott Thumma, Marcelo Timotheo da Costa, George E. “Tink” Tinker, Ola Tjørhom, Karen Jo Torjesen, Iain R. Torrance, Fernando Torres-Londoño, Archbishop Demetrios [Trakatellis], Marit Trelstad, Christine Trevett, Phyllis Trible, Johannes Tromp, Paul Turner, Robert G. Tuttle, Archbishop Desmond Tutu, Peter Tyler, Anders Tyrberg, Justin Ukpong, Javier Ulloa, Camillus Umoh, Kristi Upson-Saia, Martina Urban, Monica Uribe, Elochukwu Eugene Uzukwu, Richard Vaggione, Gabriel Vahanian, Paul Valliere, T. J. Van Bavel, Steven Vanderputten, Peter Van der Veer, Huub Van de Sandt, Louis Van Tongeren, Luke A. Veronis, Noel Villalba, Ramón Vinke, Tim Vivian, David Voas, Elena Volkova, Katharina von Kellenbach, Elina Vuola, Timothy Wadkins, Elaine M. Wainwright, Randi Jones Walker, Dewey D. Wallace, Jerry Walls, Michael J. Walsh, Philip Walters, Janet Walton, Jonathan L. Walton, Wang Xiaochao, Patricia A. Ward, David Harrington Watt, Herold D. Weiss, Laurence L. Welborn, Sharon D. Welch, Timothy Wengert, Traci C. West, Merold Westphal, David Wetherell, Barbara Wheeler, Carolinne White, Jean-Paul Wiest, Frans Wijsen, Terry L. Wilder, Felix Wilfred, Rebecca Wilkin, Daniel H. Williams, D. Newell Williams, Michael A. Williams, Vincent L. Wimbush, Gabriele Winkler, Anders Winroth, Lauri Emílio Wirth, James A. Wiseman, Ebba Witt-Brattström, Teofil Wojciechowski, John Wolffe, Kenman L. Wong, Wong Wai Ching, Linda Woodhead, Wendy M. Wright, Rose Wu, Keith E. Yandell, Gale A. Yee, Viktor Yelensky, Yeo Khiok-Khng, Gustav K. K. Yeung, Angela Yiu, Amos Yong, Yong Ting Jin, You Bin, Youhanna Nessim Youssef, Eliana Yunes, Robert Michael Zaller, Valarie H. Ziegler, Barbara Brown Zikmund, Joyce Ann Zimmerman, Aurora Zlotnik, Zhuo Xinping
- Edited by Daniel Patte, Vanderbilt University, Tennessee
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- Book:
- The Cambridge Dictionary of Christianity
- Published online:
- 05 August 2012
- Print publication:
- 20 September 2010, pp xi-xliv
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Texture Measurement of Sintered Alumina Using the Marchdollase Function
- James P. Cline, Mark D. Vaudin, John E. Blended, Carol A. Handwerker, Rodney Jiggetts, Keith J. Bowman, Nicholas Medendorp
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- Journal:
- Advances in X-ray Analysis / Volume 37 / 1993
- Published online by Cambridge University Press:
- 06 March 2019, pp. 473-478
- Print publication:
- 1993
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The Rietveld method entails the calculation of a powder diffraction pattern from crystallographic, microstructural and equipment characteristics. These characteristics are related to the form of the pattern through a series of model functions. The difference between an observed and calculated pattern is then minimized by sequentially refining the physical parameters contained within the mode) functions to obtain an accurate and precise description of the specimen. A powder diffraction pattern from a specimen exhibiting cry stallo graphic texture, or preferred orientation, will display intensity values which differ systematically from those calculated for a specimen of random orientation. This systematic discrepancy can be addressed by incorporating into the Rietveld refinement a model function for sample texture. A successful model for texture will accurately assess the phase abundance and degree of texture from both oriented and randomized specimens. In this study we use the March-Dollase model function to characterize texture development in sintered alumina with respect to processing variables and sintering time.
Influence of Ion-Implantation on Characteristics of Picosecond Photoconductive Switches
- John F. Knudsen, Robert C. Bowman, Jr., Duane D. Smith, Steven C. Moss
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- Journal:
- MRS Online Proceedings Library Archive / Volume 128 / 1988
- Published online by Cambridge University Press:
- 25 February 2011, 629
- Print publication:
- 1988
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Ion-implantation induced amorphization has been used to modify the linearity of response of ultrafast photoconductive switches fabricated on SOS. The extent of amorphization was determined using various materials characterization techniques. TRIM-86 Monte Carlo calculations were used to model the defect densities produced by ion implantation. Linearity of response is critically dependent upon the nature of the semiconductor region under metallic contacts and the character of the response is opposite to that expected from reports in the literature.
Structural Characterization of Ion Beam Enhanced Solid Phase Epitaxial Regrowth by Raman, RBS, and X-Ray Analysis
- John F. Knudsen, R. C. Bowman, Jr, P. M. Adams, R. Newman, J. P. Hurrell, R. C. Cole, L. F. Halle, D. H. Barker
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- Journal:
- MRS Online Proceedings Library Archive / Volume 126 / 1988
- Published online by Cambridge University Press:
- 21 February 2011, 177
- Print publication:
- 1988
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Epitaxial regrowth of deposited amorphous silicon has been previously described utilizing ion implantation amorphization, ion mixing and thermal anneal. This paper evaluates the effects of these process steps on crystalline quality utilizing Rutherford Backscattering (RBS), x-ray diffraction rocking curves and Raman scattering.
In situ (during implantation) regrowth results in defective crystallinity. In contrast, when there is no in situ regrowth, the post anneal crystallinity is equivalent by RBS and x-ray evaluation to virgin single crystal wafers. In situ regrowth is most pronounced during the high beam current ion mixing type implants which produce wafer temperatures of about 250°C. The final crystalline quality which results from different sequences of amorphization and ion mixing implants, is strongly dependent upon the amount of in situ regrowth which has occurred. The greater the in situ regrowth the poorer the final crystalline quality.
Whereby We Thrive: A History of American Farming, 1607–1972. By John T. Schlebecker. Ames, Iowa: Iowa State University Press, 1975. Pp. x, 342.
- John D. Bowman
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- Journal:
- The Journal of Economic History / Volume 36 / Issue 2 / June 1976
- Published online by Cambridge University Press:
- 11 May 2010, p. 506
- Print publication:
- June 1976
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Agricultural Terms of Trade in Four Midwestern States, 1870–1900
- John D. Bowman, Richard H. Keehn
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- Journal:
- The Journal of Economic History / Volume 34 / Issue 3 / September 1974
- Published online by Cambridge University Press:
- 11 May 2010, pp. 592-609
- Print publication:
- September 1974
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From the end of the Civil War down to 1900, the American agricultural sector was subject to continuous political and social upheaval. While the South and Far West were a part of this movement, the heartland of protest remained in the Midwest. The traditional view has been that this unrest and protest was at least partially based on the worsening economic position of the farmer. Farmers complained of being exploited by moneylenders, victimized by railroads and other middlemen, cheated by speculators and faced with prices received falling faster than prices paid, thus reducing real purchasing power. This last view is put forth by Faulkner: “While the prices of farm commodities declined, those of manufactured products, dominated by monopoly practices, remained high or did not decline proportionally.”
Farm Real Estate Values in the United States by Counties, 1850–1959. Edited by Thomas J. Pressly and William H. Scofield. Seattle: University of Washington Press, 1965. Pp. 69. $5.00.
- John D. Bowman
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- Journal:
- The Journal of Economic History / Volume 26 / Issue 1 / March 1966
- Published online by Cambridge University Press:
- 03 February 2011, pp. 130-132
- Print publication:
- March 1966
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