19,874 research outputs found
Anisotropic in-plane thermal conductivity of black phosphorus nanoribbons at temperatures higher than 100 K
No full textabstract: Black phosphorus attracts enormous attention as a promising layered material for electronic, optoelectronic and thermoelectric applications. Here we report large anisotropy in in-plane thermal conductivity of single-crystal black phosphorus nanoribbons along the zigzag and armchair lattice directions at variable temperatures. Thermal conductivity measurements were carried out under the condition of steady-state longitudinal heat flow using suspended-pad micro-devices. We discovered increasing thermal conductivity anisotropy, up to a factor of two, with temperatures above 100 K. A size effect in thermal conductivity was also observed in which thinner nanoribbons show lower thermal conductivity. Analysed with the relaxation time approximation model using phonon dispersions obtained based on density function perturbation theory, the high anisotropy is attributed mainly to direction-dependent phonon dispersion and partially to phonon–phonon scattering. Our results revealing the intrinsic, orientation-dependent thermal conductivity of black phosphorus are useful for designing devices, as well as understanding fundamental physical properties of layered materials.The final version of this article, as published in Nature Communications, can be viewed online at: https://www.nature.com/articles/ncomms957
Electrostatic modification of novel materials
No full textUniversity of Minnesota Ph.D. dissertation. October 2013. Major: Physics. Advisor: Allen M. Goldman. 1 computer file (PDF); viii, 119 pages.Electric double layer transistor configurations have been employed to electrostatically modify the physical properties of two novel materials; single crystals of insulating strontium titanate (SrTiO3) and thin films of amorphous indium oxide (a-InO). First the results of doping SrTiO3 over broad ranges of temperature and carrier concentration employing an ionic liquid as the gate dielectric are reported. The surprising results are, with increasing carrier concentration, an apparent carrier-density dependent conductor-insulator transition, a regime of the anomalous Hall effect, suggesting magnetic ordering, and finally the appearance of superconductivity. The possible appearance of magnetic order near the boundary between the insulating and superconducting regimes is reminiscent of effects associated with quantum critical behavior in some complex compounds. Secondly, the evolution with carrier concentration of the electrical properties of a-InO thin films has been studied. Carrier variations of up to 7 x 1014 carriers-cm-2 were achieved again using an ionic liquid as a gate dielectric. The superconductor-insulator transition was traversed, and both the magnitude and the position of large magnetoresistance peak found in the insulating regime were modified. The systematic variation of the magnetoresistance peak with charge concentration was found to be qualitatively consistent with a simulation based on a model involving granularity.Lee, Yeonbae. (2013). Electrostatic modification of novel materials. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/161013
Who Was Edmund Lee?
No full textLocal author Peggy Donoho discusses her pioneer ancestor, Edmund Lee, and her work to preserve their family cemetery
The Future of Canadian Climate Policy — with Marc Lee
No full textMarc Lee is a Senior Economist at the Canadian Centre for Policy Alternatives\u27 BC Office. In addition to tracking federal and provincial budgets and economic trends, Marc has published on a range of topics from poverty and inequality to globalization and international trade to public services and regulation. Marc is the Co-Director of the Climate Justice Project, a research partnership with UBC\u27s School of Community and Regional Planning that examines the links between climate change policies and social justice.Resources:Climate Justice Project: www.policyalternatives.ca/projects/cli…tice-projectMarc Lee\u27s Posts on Policy Note: www.policynote.ca/author/marclee/Canadian Centre for Policy Alternatives: www.policyalternatives.ca/Marc\u27s Twitter: twitter.com/MarcLeeCCPA International Panel on Climate Change, 2021 report: www.ipcc.ch/report/ar6/wg1
Dr. Aleksandra Sznajder Lee – Faculty Author Interview
No full textDr. Aleksandra Sznajder Lee, Associate Professor of Political Science, discusses her new book, Transnational Capitalism in East Central Europe’s Heavy Industry, published recently by the University of Michigan Press. Focusing on the steel industry during the post-communist transition from 1989 through 2009, Dr. Sznajder Lee traces the transformation of flagship state enterprises in the Czech Republic, Poland, Romania, and Slovakia into the subsidiaries of large, international corporations
Letter from K.W. Lee to Friends of Michi Weglyn, November 1, 1997
No full textA letter from K. W. (Kyung Won) Lee, an investigative journalist who wrote for the Sacramento Union, to the Friends of Michi Weglyn. Lee wrote that Weglyn was instrumental in the campaign to free Chol Soo Lee, a Korean American man was on death row, but later had his convictions overturned. Lee also wrote that other Japanese American activists were instrumental to the success of this campaign.These materials are from box 73 and 74 of the Frank Chin Papers. The Frank Chin Papers contain personal and professional correspondence between Frank Chin and Michi Weglyn relating to particular projects on which either author was working as well as files related to the Day of Remembrance Tribute to Michi Weglyn
Francis Lee Utley (interview)
No full textThis interview is included in the American Folklore Society Oral History Project held at the Archive of Folk Culture, American Folklife Center, Library of Congress, Washington, D.C. This item consists of oral history interviews with folklorist Francis Lee Utley conducted in 1973 by Patrick B. Mullen and Richard Reuss for the American Folklore Society Oral History Project. This collection consists of 2 sound tape reels : analog, 3 3/4 ips, 2 track, mono. ; 7 in. Originally recorded on July 19, 1973 by Patrick B. Mullen on a 7-inch reel, 3 3/4 ips, 2 track at an unidentified location; and on November 3, 1973 by Patrick B. Mullen and by Richard Reuss at the annual meeting of the American Folklore Society in Nashville, Tennessee on a Sony audiocassette. Sound recordings are first generation copies on two sound tape reels, 7 in. Biography/History note: Francis Lee Utley was born May 25, 1907 in Watertown, Wisconsin, and died March 8, 1974. He was a folklorist, medievalist, linguist, educator, and author who earned his M.A. in 1934 and Ph.D. in 1936 in literature at Harvard University. He taught at Ohio State University and the University of California at Berkeley, and was president of the American Folklore Society from 1951-1952
Enhancing Modulation of Thermal Conduction in Vanadium Dioxide Thin Film by Nanostructured Nanogaps
No full textEfficient thermal management at the nanoscale is important for reducing energy consumption and dissipation in electronic devices, lab-on-a-chip platforms and energy harvest/conversion systems. For many of these applications, it is much desired to have a solid-state structure that reversibly switches thermal conduction with high ON/OFF ratios and at high speed. Here we describe design and implementation of a novel, all-solid-state thermal switching device by nanostructured phase transformation, i.e., modulation of contact pressure and area between two poly-silicon surfaces activated by microstructural change of a vanadium dioxide (VO2) thin film. Our solid-state devices demonstrate large and reversible alteration of cross-plane thermal conductance as a function of temperature, achieving a conductance ratio of at least 2.5. Our new approach using nanostructured phase transformation provides new opportunities for applications that require advanced temperature and heat regulations
Dear SIS Seminar, Nina June Lee, Young Scholar, Fall 2020
No full textNina J. Lee is a graduating senior Comparative Women�s Studies Major from Everett, Massachusetts. After Spelman, she will pursue a Masters of Education in Community Engagement with a concentration in Community Organizations and Nonprofit Management
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