11 results
Acoustic measurement of under-expanded jet and its numerical prediction
- S. Kang, T. Park, H. Joo, S. Im, I. Jang, W. Ohm, S.-J. Shin
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- Journal:
- The Aeronautical Journal / Volume 126 / Issue 1303 / September 2022
- Published online by Cambridge University Press:
- 04 February 2022, pp. 1510-1526
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Intense acoustic loads from jet noise cause noise pollution and induce failures, such as the malfunctioning of electronic devices and fatigue failure of internal/external structures. Consequently, the prediction of jet noise characteristics is crucial in the development of high-speed vehicles. This study presents acoustic experiments and predictions for an under-expanded, unheated jet using a small-scale prototype. Outdoor measurements are carried out using a vertical ejection setup. Acoustic characteristics are measured using both linear and circular microphone arrays. Additionally, numerical prediction of the same jet noise is performed using a detached eddy simulation and the permeable Ffowcs-Williams and Hawkings acoustic analogy. The vertical experimental setup exhibits the typical acoustic characteristics of a supersonic jet in terms of directivity and broadband shock-associated noise. Moreover, the numerical prediction exhibits satisfactory accuracy for the jet downstream, where the large-scale turbulence structures of the directivity predominate. However, discrepancy increases in the domain of lower directivity. The presented experiment and prediction will be extended to future studies regarding the noise of various deflector duct configurations impinging on supersonic jets.
Lateral neck dissection affects the voice in thyroid cancer patients
- I-C Nam, J-S Bae, S-H Lee, J-O Park, S-Y Kim, Y-H Joo, Y-H Park, D-I Sun
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- Journal:
- The Journal of Laryngology & Otology / Volume 131 / Issue 10 / October 2017
- Published online by Cambridge University Press:
- 31 July 2017, pp. 853-859
- Print publication:
- October 2017
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Objective:
This study aimed to identify the effect of lateral neck dissection on voice change in thyroidectomised patients.
Methods:Medical records from 264 patients who underwent thyroidectomy with (n = 65) or without (n = 199) lateral neck dissection were reviewed. Clinical and voice evaluation data were compared between the two groups.
Results:Patients who underwent surgery that included lateral neck dissection had lower fundamental frequencies and speaking fundamental frequencies. They also had a higher incidence of asymmetric mucosal wave and vocal fold oedema on videostroboscopy during the first month after surgery, with the incidence of vocal fold oedema remaining significantly higher at three months. Self-assessed voice quality scores were significantly higher in lateral neck dissection patients at both one and three months after surgery.
Conclusion:In thyroidectomised patients, lateral neck dissection lowers the vocal pitch in the initial period after surgery and induces vocal fold oedema that persists for several months. Although most objective parameters improved within a month, subjective symptoms lasted for longer.
Contributors
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- By Mitchell Aboulafia, Frederick Adams, Marilyn McCord Adams, Robert M. Adams, Laird Addis, James W. Allard, David Allison, William P. Alston, Karl Ameriks, C. Anthony Anderson, David Leech Anderson, Lanier Anderson, Roger Ariew, David Armstrong, Denis G. Arnold, E. J. Ashworth, Margaret Atherton, Robin Attfield, Bruce Aune, Edward Wilson Averill, Jody Azzouni, Kent Bach, Andrew Bailey, Lynne Rudder Baker, Thomas R. Baldwin, Jon Barwise, George Bealer, William Bechtel, Lawrence C. Becker, Mark A. Bedau, Ernst Behler, José A. Benardete, Ermanno Bencivenga, Jan Berg, Michael Bergmann, Robert L. Bernasconi, Sven Bernecker, Bernard Berofsky, Rod Bertolet, Charles J. Beyer, Christian Beyer, Joseph Bien, Joseph Bien, Peg Birmingham, Ivan Boh, James Bohman, Daniel Bonevac, Laurence BonJour, William J. Bouwsma, Raymond D. Bradley, Myles Brand, Richard B. Brandt, Michael E. Bratman, Stephen E. Braude, Daniel Breazeale, Angela Breitenbach, Jason Bridges, David O. Brink, Gordon G. Brittan, Justin Broackes, Dan W. Brock, Aaron Bronfman, Jeffrey E. Brower, Bartosz Brozek, Anthony Brueckner, Jeffrey Bub, Lara Buchak, Otavio Bueno, Ann E. Bumpus, Robert W. Burch, John Burgess, Arthur W. Burks, Panayot Butchvarov, Robert E. Butts, Marina Bykova, Patrick Byrne, David Carr, Noël Carroll, Edward S. Casey, Victor Caston, Victor Caston, Albert Casullo, Robert L. Causey, Alan K. L. Chan, Ruth Chang, Deen K. Chatterjee, Andrew Chignell, Roderick M. Chisholm, Kelly J. Clark, E. J. Coffman, Robin Collins, Brian P. Copenhaver, John Corcoran, John Cottingham, Roger Crisp, Frederick J. Crosson, Antonio S. Cua, Phillip D. Cummins, Martin Curd, Adam Cureton, Andrew Cutrofello, Stephen Darwall, Paul Sheldon Davies, Wayne A. Davis, Timothy Joseph Day, Claudio de Almeida, Mario De Caro, Mario De Caro, John Deigh, C. F. Delaney, Daniel C. Dennett, Michael R. DePaul, Michael Detlefsen, Daniel Trent Devereux, Philip E. Devine, John M. Dillon, Martin C. Dillon, Robert DiSalle, Mary Domski, Alan Donagan, Paul Draper, Fred Dretske, Mircea Dumitru, Wilhelm Dupré, Gerald Dworkin, John Earman, Ellery Eells, Catherine Z. Elgin, Berent Enç, Ronald P. Endicott, Edward Erwin, John Etchemendy, C. Stephen Evans, Susan L. Feagin, Solomon Feferman, Richard Feldman, Arthur Fine, Maurice A. Finocchiaro, William FitzPatrick, Richard E. Flathman, Gvozden Flego, Richard Foley, Graeme Forbes, Rainer Forst, Malcolm R. Forster, Daniel Fouke, Patrick Francken, Samuel Freeman, Elizabeth Fricker, Miranda Fricker, Michael Friedman, Michael Fuerstein, Richard A. Fumerton, Alan Gabbey, Pieranna Garavaso, Daniel Garber, Jorge L. A. Garcia, Robert K. Garcia, Don Garrett, Philip Gasper, Gerald Gaus, Berys Gaut, Bernard Gert, Roger F. Gibson, Cody Gilmore, Carl Ginet, Alan H. Goldman, Alvin I. Goldman, Alfonso Gömez-Lobo, Lenn E. Goodman, Robert M. Gordon, Stefan Gosepath, Jorge J. E. Gracia, Daniel W. Graham, George A. Graham, Peter J. Graham, Richard E. Grandy, I. Grattan-Guinness, John Greco, Philip T. Grier, Nicholas Griffin, Nicholas Griffin, David A. Griffiths, Paul J. Griffiths, Stephen R. Grimm, Charles L. Griswold, Charles B. Guignon, Pete A. Y. Gunter, Dimitri Gutas, Gary Gutting, Paul Guyer, Kwame Gyekye, Oscar A. Haac, Raul Hakli, Raul Hakli, Michael Hallett, Edward C. Halper, Jean Hampton, R. James Hankinson, K. R. Hanley, Russell Hardin, Robert M. Harnish, William Harper, David Harrah, Kevin Hart, Ali Hasan, William Hasker, John Haugeland, Roger Hausheer, William Heald, Peter Heath, Richard Heck, John F. Heil, Vincent F. Hendricks, Stephen Hetherington, Francis Heylighen, Kathleen Marie Higgins, Risto Hilpinen, Harold T. Hodes, Joshua Hoffman, Alan Holland, Robert L. Holmes, Richard Holton, Brad W. Hooker, Terence E. Horgan, Tamara Horowitz, Paul Horwich, Vittorio Hösle, Paul Hoβfeld, Daniel Howard-Snyder, Frances Howard-Snyder, Anne Hudson, Deal W. Hudson, Carl A. Huffman, David L. Hull, Patricia Huntington, Thomas Hurka, Paul Hurley, Rosalind Hursthouse, Guillermo Hurtado, Ronald E. Hustwit, Sarah Hutton, Jonathan Jenkins Ichikawa, Harry A. Ide, David Ingram, Philip J. Ivanhoe, Alfred L. Ivry, Frank Jackson, Dale Jacquette, Joseph Jedwab, Richard Jeffrey, David Alan Johnson, Edward Johnson, Mark D. Jordan, Richard Joyce, Hwa Yol Jung, Robert Hillary Kane, Tomis Kapitan, Jacquelyn Ann K. Kegley, James A. Keller, Ralph Kennedy, Sergei Khoruzhii, Jaegwon Kim, Yersu Kim, Nathan L. King, Patricia Kitcher, Peter D. Klein, E. D. Klemke, Virginia Klenk, George L. Kline, Christian Klotz, Simo Knuuttila, Joseph J. Kockelmans, Konstantin Kolenda, Sebastian Tomasz Kołodziejczyk, Isaac Kramnick, Richard Kraut, Fred Kroon, Manfred Kuehn, Steven T. Kuhn, Henry E. Kyburg, John Lachs, Jennifer Lackey, Stephen E. Lahey, Andrea Lavazza, Thomas H. Leahey, Joo Heung Lee, Keith Lehrer, Dorothy Leland, Noah M. Lemos, Ernest LePore, Sarah-Jane Leslie, Isaac Levi, Andrew Levine, Alan E. Lewis, Daniel E. Little, Shu-hsien Liu, Shu-hsien Liu, Alan K. L. Chan, Brian Loar, Lawrence B. Lombard, John Longeway, Dominic McIver Lopes, Michael J. Loux, E. J. Lowe, Steven Luper, Eugene C. Luschei, William G. Lycan, David Lyons, David Macarthur, Danielle Macbeth, Scott MacDonald, Jacob L. Mackey, Louis H. Mackey, Penelope Mackie, Edward H. Madden, Penelope Maddy, G. B. Madison, Bernd Magnus, Pekka Mäkelä, Rudolf A. Makkreel, David Manley, William E. Mann (W.E.M.), Vladimir Marchenkov, Peter Markie, Jean-Pierre Marquis, Ausonio Marras, Mike W. Martin, A. P. Martinich, William L. McBride, David McCabe, Storrs McCall, Hugh J. McCann, Robert N. McCauley, John J. McDermott, Sarah McGrath, Ralph McInerny, Daniel J. McKaughan, Thomas McKay, Michael McKinsey, Brian P. McLaughlin, Ernan McMullin, Anthonie Meijers, Jack W. Meiland, William Jason Melanson, Alfred R. Mele, Joseph R. Mendola, Christopher Menzel, Michael J. Meyer, Christian B. Miller, David W. Miller, Peter Millican, Robert N. Minor, Phillip Mitsis, James A. Montmarquet, Michael S. Moore, Tim Moore, Benjamin Morison, Donald R. Morrison, Stephen J. Morse, Paul K. Moser, Alexander P. D. Mourelatos, Ian Mueller, James Bernard Murphy, Mark C. Murphy, Steven Nadler, Jan Narveson, Alan Nelson, Jerome Neu, Samuel Newlands, Kai Nielsen, Ilkka Niiniluoto, Carlos G. Noreña, Calvin G. Normore, David Fate Norton, Nikolaj Nottelmann, Donald Nute, David S. Oderberg, Steve Odin, Michael O’Rourke, Willard G. Oxtoby, Heinz Paetzold, George S. Pappas, Anthony J. Parel, Lydia Patton, R. P. Peerenboom, Francis Jeffry Pelletier, Adriaan T. Peperzak, Derk Pereboom, Jaroslav Peregrin, Glen Pettigrove, Philip Pettit, Edmund L. Pincoffs, Andrew Pinsent, Robert B. Pippin, Alvin Plantinga, Louis P. Pojman, Richard H. Popkin, John F. Post, Carl J. Posy, William J. Prior, Richard Purtill, Michael Quante, Philip L. Quinn, Philip L. Quinn, Elizabeth S. Radcliffe, Diana Raffman, Gerard Raulet, Stephen L. Read, Andrews Reath, Andrew Reisner, Nicholas Rescher, Henry S. Richardson, Robert C. Richardson, Thomas Ricketts, Wayne D. Riggs, Mark Roberts, Robert C. Roberts, Luke Robinson, Alexander Rosenberg, Gary Rosenkranz, Bernice Glatzer Rosenthal, Adina L. Roskies, William L. Rowe, T. M. Rudavsky, Michael Ruse, Bruce Russell, Lilly-Marlene Russow, Dan Ryder, R. M. Sainsbury, Joseph Salerno, Nathan Salmon, Wesley C. Salmon, Constantine Sandis, David H. Sanford, Marco Santambrogio, David Sapire, Ruth A. Saunders, Geoffrey Sayre-McCord, Charles Sayward, James P. Scanlan, Richard Schacht, Tamar Schapiro, Frederick F. Schmitt, Jerome B. Schneewind, Calvin O. Schrag, Alan D. Schrift, George F. Schumm, Jean-Loup Seban, David N. Sedley, Kenneth Seeskin, Krister Segerberg, Charlene Haddock Seigfried, Dennis M. Senchuk, James F. Sennett, William Lad Sessions, Stewart Shapiro, Tommie Shelby, Donald W. Sherburne, Christopher Shields, Roger A. Shiner, Sydney Shoemaker, Robert K. Shope, Kwong-loi Shun, Wilfried Sieg, A. John Simmons, Robert L. Simon, Marcus G. Singer, Georgette Sinkler, Walter Sinnott-Armstrong, Matti T. Sintonen, Lawrence Sklar, Brian Skyrms, Robert C. Sleigh, Michael Anthony Slote, Hans Sluga, Barry Smith, Michael Smith, Robin Smith, Robert Sokolowski, Robert C. Solomon, Marta Soniewicka, Philip Soper, Ernest Sosa, Nicholas Southwood, Paul Vincent Spade, T. L. S. Sprigge, Eric O. Springsted, George J. Stack, Rebecca Stangl, Jason Stanley, Florian Steinberger, Sören Stenlund, Christopher Stephens, James P. Sterba, Josef Stern, Matthias Steup, M. A. Stewart, Leopold Stubenberg, Edith Dudley Sulla, Frederick Suppe, Jere Paul Surber, David George Sussman, Sigrún Svavarsdóttir, Zeno G. Swijtink, Richard Swinburne, Charles C. Taliaferro, Robert B. Talisse, John Tasioulas, Paul Teller, Larry S. Temkin, Mark Textor, H. S. Thayer, Peter Thielke, Alan Thomas, Amie L. Thomasson, Katherine Thomson-Jones, Joshua C. Thurow, Vzalerie Tiberius, Terrence N. Tice, Paul Tidman, Mark C. Timmons, William Tolhurst, James E. Tomberlin, Rosemarie Tong, Lawrence Torcello, Kelly Trogdon, J. D. Trout, Robert E. Tully, Raimo Tuomela, John Turri, Martin M. Tweedale, Thomas Uebel, Jennifer Uleman, James Van Cleve, Harry van der Linden, Peter van Inwagen, Bryan W. Van Norden, René van Woudenberg, Donald Phillip Verene, Samantha Vice, Thomas Vinci, Donald Wayne Viney, Barbara Von Eckardt, Peter B. M. Vranas, Steven J. Wagner, William J. Wainwright, Paul E. Walker, Robert E. Wall, Craig Walton, Douglas Walton, Eric Watkins, Richard A. Watson, Michael V. Wedin, Rudolph H. Weingartner, Paul Weirich, Paul J. Weithman, Carl Wellman, Howard Wettstein, Samuel C. Wheeler, Stephen A. White, Jennifer Whiting, Edward R. Wierenga, Michael Williams, Fred Wilson, W. Kent Wilson, Kenneth P. Winkler, John F. Wippel, Jan Woleński, Allan B. Wolter, Nicholas P. Wolterstorff, Rega Wood, W. Jay Wood, Paul Woodruff, Alison Wylie, Gideon Yaffe, Takashi Yagisawa, Yutaka Yamamoto, Keith E. Yandell, Xiaomei Yang, Dean Zimmerman, Günter Zoller, Catherine Zuckert, Michael Zuckert, Jack A. Zupko (J.A.Z.)
- Edited by Robert Audi, University of Notre Dame, Indiana
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- The Cambridge Dictionary of Philosophy
- Published online:
- 05 August 2015
- Print publication:
- 27 April 2015, pp ix-xxx
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First norovirus outbreaks associated with consumption of green seaweed (Enteromorpha spp.) in South Korea
- J. H. PARK, H. S. JEONG, J. S. LEE, S. W. LEE, Y. H. CHOI, S. J. CHOI, I. S. JOO, Y. R. KIM, Y. K. PARK, S. K. YOUN
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- Journal:
- Epidemiology & Infection / Volume 143 / Issue 3 / February 2015
- Published online by Cambridge University Press:
- 27 May 2014, pp. 515-521
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In February 2012, an outbreak of gastroenteritis was reported in school A; a successive outbreak was reported at school B. A retrospective cohort study conducted in school A showed that seasoned green seaweed with radishes (relative risk 7·9, 95% confidence interval 1·1–56·2) was significantly associated with illness. Similarly, a case-control study of students at school B showed that cases were 5·1 (95% confidence interval 1·1–24·8) times more likely to have eaten seasoned green seaweed with pears. Multiple norovirus genotypes were detected in samples from students in schools A and B. Norovirus GII.6 isolated from schools A and B were phylogenetically indistinguishable. Green seaweed was supplied by company X, and norovirus GII.4 was isolated from samples of green seaweed. Green seaweed was assumed to be linked to these outbreaks. To our knowledge, this is the first reported norovirus outbreak associated with green seaweed.
Contributors
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- By Mark S. Aloia, Ellemarije Altena, Peter Anderer, Christopher L. Asplund, Nitin Bangera, Jeroen S. Benjamins, Daniela Berg, Bohdan Bybel, Vincenza Castronovo, Suk-tak Chan, Michael W. L. Chee, Pietro Cortelli, Michael Czisch, Joseph T. Daley, Thien Thanh Dang-Vu, Yazmín de la Garza-Neme, Lourdes DelRosso, Derk-Jan Dijk, Maria Engström, Thorleif Etgen, Bruce J. Fisch, Ariane Foret, Patrice Fort, Steffen Gais, Anne Germain, Jana Godau, Andrew L. Goertzen, William A. Gomes, Ronald M. Harper, Seung Bong Hong, Romy Hoque, Scott A. Huettel, Yuichi Inoue, Alex Iranzo, Mathieu Jaspar, Zayd Jedidi, Alejandro Jiménez-Genchi, Eun Yeon Joo, Gerhard Klösch, Karsten Krakow, Rajesh Kumar, Caroline Kussé, Hans-Peter Landolt, Helmut Laufs, Jeffrey David Lewine, Camilo Libedinsky, Michael L. Lipton, Mordechai Lorberboym, Cheng Luo, Pierre-Hervé Luppi, Paul M. Macey, Pierre Maquet, Laura Mascetti, Christelle Meyer, Sarah Moens, Vincenzo Muto, Shadreck Mzengeza, Eric Nofzinger, Takashi Nomura, Daniela Perani, Jennifer R. Ramautar, Bernd Saletu, Michael T. Saletu, Gerda Saletu-Zyhlarz, Christina Schmidt, Monika Schönauer, Richard J. Schwab, Sophie Schwartz, Keivan Shifteh, Sanjib Sinha, Victor I. Spoormaker, Ryan P. J. Stocker, A. Jon Stoessl, Diederick Stoffers, A. B. Taly, Robert Joseph Thomas, Michael J. Thorpy, Emily Urry, Jason Valerio, Ysbrand D. Van Der Werf, Gilles Vandewalle, Hans P. A. Van Dongen, Eus J. W. Van Someren, Vinod Venkatraman, Frederic von Wegner, Thomas C. Wetter, Dezhong Yao
- Edited by Eric Nofzinger, University of Pittsburgh, Pierre Maquet, Université de Liège, Belgium, Michael J. Thorpy
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- Neuroimaging of Sleep and Sleep Disorders
- Published online:
- 05 March 2013
- Print publication:
- 07 March 2013, pp viii-xii
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- By Ashok Agarwal, Linda D. Applegarth, Nelson E. Bennett, Nancy L. Brackett, Melissa B. Brisman, Mark F. H. Brougham, Cara B. Cimmino, Owen K. Davis, Rian J. Dickstein, Michael L. Eisenberg, Mikkel Fode, Gretchen A. Gignac, Bruce R. Gilbert, Ellen R. Goldmark, Marc Goldstein, Wayne J. G. Hellstrom, Wayland Hsiao, Jack Huang, Kathleen Hwang, Ann A. Jakubowski, Keith Jarvi, Loren Jones, Hey-Joo Kang, Joanne Frankel Kelvin, Mohit Khera, Thomas F. Kolon, Kate H. Kraft, Andrew C. Kramer, Dolores J. Lamb, Andrew B. Lassman, Helen R. Levey, Larry I. Lipshultz, Charles M. Lynne, Akanksha Mehta, Marvin L. Meistrich, Gregory C. Mitchell, Mark A. Moyad, John P. Mulhall, Lauren Murray, Craig Niederberger, Ariella Noy, Robert D. Oates, Dana A. Ohl, Kutluk Oktay, Ndidiamaka Onwubalili, Fabio Firmbach Pasqualatto, Elena Pentsova, Susanne A. Quallich, Gwendolyn P. Quinn, Alex Ridgeway, Matthew T. Roberts, Kenny A. Rodriguez-Wallberg, Allison B. Rosen, Lisa Rosenzweig, Edmund S. Sabanegh, Hossein Sadeghi-Nejad, Mary K. Samplaski, Jay I. Sandlow, Peter N. Schlegel, Gunapala Shetty, Mark Sigman, Jens Sønksen, Peter J. Stahl, Eytan Stein, Doron S. Stember, Raanan Tal, Susan T. Vadaparampil, W. Hamish, B. Wallace, Leonard H. Wexler, Daniel H. Williams
- Edited by John P. Mulhall, Memorial Sloan-Kettering Cancer Center, New York
- Edited in association with Linda D. Applegarth, Robert D. Oates, Peter N. Schlegel
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- Fertility Preservation in Male Cancer Patients
- Published online:
- 05 March 2013
- Print publication:
- 21 February 2013, pp vii-x
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Microencapsulation of Oil in Organically Modified Silicate Glass by Sol-Gel Process
- Sang I. Seok, Bok Y. Ahn, Joo H. Kim, Tae S. Suh
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- Journal:
- MRS Online Proceedings Library Archive / Volume 726 / 2002
- Published online by Cambridge University Press:
- 01 February 2011, Q6.34
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- 2002
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Microencapsulation provides protection and sustained or controlled release of active core agents. The sol-gel process has opened up a new way for encapsulating oil droplets within an inorganic capsule. Silica microcapsules were prepared in silica precursor-oil mixtures/NH4OH water microemulsion system. In this step, the formation of capsules incorporating oil depended strongly on the type of silica precursor. A spherical silica microsheres were only obtained when oligomer, synthesized by the hydrolysis and co-condensation of equiweight of TEOS (tetraethylorthosilicate) and MTMS (methyltrimethoxysilane), was used as the wall materials. The particles size of silica microcapsules was in the range of 1 ∼ 100 μm, depending on processing parameter such as a shear rate and O/W ratio etc. In controlled release system, the shell porosity is important to give an appropriate permeability, corresponding to the release rate. The pore structure, responsible for permeability, was adjusted by doping alkyl silane, and investigated with nitrogen sorption measurement.
Preparation and ferroelectric properties of mixed composition layered lead zirconate titanate thin films for nonvolatile memory applications
- Seung-Hyun Kim, Dong-Joo Kim, S. K. Streiffer, A. I. Kingon
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- Journal:
- Journal of Materials Research / Volume 14 / Issue 6 / June 1999
- Published online by Cambridge University Press:
- 31 January 2011, pp. 2476-2483
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- June 1999
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Mixed composition layered lead zirconate titanate (PZT) films sZr/Ti ratio = 30/70 + 65/35d with stoichiometric lead containing PZT thin layer at the film/electrode interface were successfully fabricated by a modified chemical solution deposition method. These modified PZT thin films are highly (111) textured, and have square-shaped P-E hysteresis loops with large remanent polarization and low coercive field, as well as low saturation voltage. In addition, these films show good fatigue and imprint behavior with Pt electrodes; the retained polarization of the modified film was above 50% after fatigue testing to 109 cycles, and the thermally induced voltage shifts (ΔV) were 0.51 V after heating at 150 °C for 4410 s, two times lower than for films without a stoichiometric thin layer.
Imprint and Fatigue Properties of Chemical Solution Derived Pb1–-xLax(ZryTi1–y)1–x/4O3 Thin Films
- Seung-Hyun Kim, Dong-Joo Kim, JoonGoo Hong, S. K. Streiffer, A. I. Kingon
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- Journal:
- Journal of Materials Research / Volume 14 / Issue 4 / April 1999
- Published online by Cambridge University Press:
- 31 January 2011, pp. 1371-1377
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- April 1999
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We have investigated the effect of oxygen vacancies on imprint and fatigue behavior of the PLZT thin films. It is found that the compensation of oxygen vacancies with various dopant concentrations and electrode structures is an important process parameter in determining the tendency to imprint and fatigue. In the case of PLZT thin films, the voltage shifts related to imprint are attributed to the trapping of electrons at ionic defect sites such as oxygen vacancies near the film/electrode interface, the magnitude of polarization, and concentration of defect-dipole complexes involving oxygen vacancies such as V′Pb–V••o. The strong dependence of fatigue rate on electrode material for PLZT thin films is due to the effect of the ferroelectric/electrode interaction on the pinning and/or unpinning rate involving the accumulation of oxygen vacancies near the film/electrode interface during fatigue cycling. By using RuO2 as the top and/or bottom electrode instead of Pt, improved fatigue properties are obtained compared to Pt/PLZT/Pt capacitors. This is because a reduced accumulation of oxygen vacancies near the interface by the oxide electrode such as RuO2 may reduce the electronic charge trapping and, consequently, lead to less domain wall pinning.
The Characteristics of LPCVD Aluminum Films: Nucleation and Selectivity
- K.-I. Lee, Y.-S. Kim, S.-K. Joo
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- MRS Online Proceedings Library Archive / Volume 280 / 1992
- Published online by Cambridge University Press:
- 25 February 2011, 197
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- 1992
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Growth kinetics of CVD Al films using TIBA(Tri-IsoButyl-Aluminum) as a source material were investigated. Nucleation activation energy of aluminum on the silicon substrate was determined to be 3.2 eV for the first time in this work. It turned out that selectivity between Si and SiO2 was very sensitive to the substrate temperature during deposition, which could be well explained from the nucleation activation energy derived in this work. It was found that the surface topology of aluminum films could be improved by reduction of nucleation activation energy through pre-treatment of the substrate.
A New Device Model of Amorphous Silicon Thin-Film Transistor for Circuit Simulation
- Hong S. Choi, Jin S. Park, Chang H. Oh, In S. Joo, Yong S. Kim, Min K. Han, Yearn I. Choi, Jung G. Yun, Won K. Park, Woo Y. Kim
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- Journal:
- MRS Online Proceedings Library Archive / Volume 219 / 1991
- Published online by Cambridge University Press:
- 21 February 2011, 351
- Print publication:
- 1991
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We present a new analytical model of amorphous silicon thin-film transistor (a-Si TFT) suitable for circuit simulators such as SPICE. The effects of localized gap state distributions of a-Si as well as temperatures on the a-Si TFT performances have been fully considered in the presented model. The parameters used in SPICE, such as transconductance, channel-length modulation, and power factor of source-drain current, are evaluated from the measured current-voltage and capacitance-voltage characteristics by employing the proposed extraction method. It has been found out that the analytical model is in good agreement with experimental data at both room temperature and elevated temperature and successfully implemented in a widely used circuit simulator.