Importance of van der Waals interactions for ab initio studies of topological insulators

We investigate the lattice and electronic structures of the bulk and surface of the prototypical layered topological insulators Bi$_2$Se$_3$ and Bi$_2$Te$_3$ using ab initio density functional methods, and systematically compare the results of different methods of including van der Waals (vdW) interactions. We show that the methods utilizing semi-empirical energy corrections yield accurate descriptions of these materials, with the most precise results obtained by properly accounting for the long-range tail of the vdW interactions. The bulk lattice constants, distances between quintuple layers and the Dirac velocity of the topological surface states (TSS) are all in excellent agreement with experiment. In Bi$_2$Te$_3$, hexagonal warping of the energy dispersion leads to complex spin textures of the TSS at moderate energies, while in Bi$_2$Se$_3$ these states remain almost perfectly helical away from the Dirac point, showing appreciable signs of hexagonal warping at much higher energies, above the minimum of the bulk conduction band. Our results establish a framework for unified and systematic self-consistent first principles calculations of topological insulators in bulk, slab and interface geometries, and provides the necessary first step towards ab initio modeling of topological heterostructures.Comment: 26 pages, 7 figures. This is the Accepted Manuscript version of an article accepted for publication in Journal of Physics: Condensed Matter. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at https://dx.doi.org/10.1088/1361-648X/abbdb

"Against the Public": Teacher Strikes and the Decline of Liberalism, 1968-1981

In the 1930s, the Democratic Party became the party of working people largely through its support of legislation encouraging the formation of labor unions. As the nation moved leftward, a liberal consensus emerged that placed support--in the name of both economic growth and greater social equality--for labor unions at it center. Support for this labor-liberalism declined considerably during the 1970s, paving the way for the neoliberal conservatism that has emerged in the last quarter century of American politics. This dissertation explains this shift by looking at the intersection between culture and the public sector labor movement in the postwar era. As unionized teachers became increasingly visible in American political culture in the 1960s, lengthy strikes by teachers in major metropolitan areas in the 1970s caused many Americans to question their assumptions about the role of the state and the importance of labor unions. Because of teachers' long-time cultural importance as providers of economic opportunity as well as inculcators of moral values, their labor stoppages (which were often violations of the law) caused many white working- and middle-class Americans to blame the excesses of the liberal state for moral decline and to re-think their views about what had made America so prosperous in the years following World War II. Further, the state's failure to solve the thorny problem of teachers shutting down the school system also caused many of these future "Reagan Democrats" to question the efficacy of the liberal state. With labor-liberalism discredited, free-market conservatives began, by the end of the decade, to argue persuasively for a shift to a more austere state, less government regulation of business, and for the privatization of social goods like education. This dissertation charts these larger developments by putting close examinations of teacher strikes in Newark, Philadelphia, Pittsburgh, Baltimore, and St. Louis in dialogue with the national trajectory of neoliberal conservatism

Estimating the Economic Impact of Disease on a Local Economy: The Case of Diabetes in the Lower Rio Grande Valley of Texas

The purpose of this study is to investigate the economic impact of wage reductions that people experience from contracting diabetes. Incorporating wage reduction information into an input-output model reveals that as diabetics' wages decrease by $1.00, production and income in the local economy decline by$0.36 and $0.38, respectively.Health Economics and Policy,

Far-ultraviolet Emission-line Morphologies of the Supernova Remnant G65.3+5.7

We present the first far-ultraviolet (FUV) emission-line morphologies of the whole region of the supernova remnant (SNR) G65.3+5.7 using the FIMS/SPEAR data. The morphologies of the C IV {\lambda}{\lambda}1548, 1551, He II {\lambda}1640, and O III] {\lambda}{\lambda}1661, 1666 lines appear to be closely related to the optical and/or soft X-ray images obtained in previous studies. Dramatic differences between the C IV morphology and the optical [O III] {\lambda}5007 image provide clues to a large resonant-scattering region and a foreground dust cloud. The FUV morphologies also reveal the overall distribution of various shocks in different evolutionary phases and an evolutionary asymmetry between the east and the southwest sides in terms of Galactic coordinates, possibly due to a Galactic density gradient in the global scale. The relative X-ray luminosity of G65.3+5.7 to C IV luminosity is considerably lower than those of the Cygnus Loop and the Vela SNRs. This implies that G65.3+5.7 has almost evolved into the radiative stage in the global sense and supports the previous proposal that G65.3+5.7 has lost its bright X-ray shell and become a member of mixed-morphology SNRs as it has evolved beyond the adiabatic stage.Comment: 6 pages, 3 figures, accepted for publication in The Ap

Problems in Human Rights and Transboundary Pollution

This case study was intended to be included in Anton & Shelton, Environmental Problems and Human Rights (Cambridge, 2011), but space limitations forced its omission from the printed text. Using the Application Instituting Proceedings in the International Court of Justice case involving Arial Herbicide Spraying (Ecuador v. Columbia) [2008] ICJ 4-28 General List No. 138 (March 31, 2008)(footnote omitted), this case study raises questions associated with human rights and international environmental law

Problems in Human Rights and Large Dams

This case study was intended to be included in Anton & Shelton, Environmental Problems and Human Rights (Cambridge, 2011), but space limitations forced its omission from the printed text. Among large infrastructure projects, damming rivers to provide hydroelectric power have been the source of considerable conflict between governments and the people who are affected by such projects, especially those forced to relocate. In many instances dams are built in pristine natural areas, destroying or degrading nature reserves, indigenous lands and/or archaeological sites. Increasing opposition to large dams has resulted in national and international litigation, as well as substantial changes in the practices of international financial institutions. This case study looks at the case of the Narmada dam in India, as it has evolved over time in response to public action, national litigation, and challenges to World Bank financing. In reading these materials, consider the following issues: (1) In developing countries, do the benefits of flood control and the provision of renewable energy outweigh the environmental and human rights impacts of large dams? (2) Can equal or greater benefits be achieved by alternative development projects that have fewer negative impacts on the environment and human rights? (3) By what procedures and substantive measures can the negative impacts be avoided or mitigated? (4) Even if there are considerable benefits to hydroelectric projects, should certain locations be off-limits to the construction of large dams? If so, what are the relevant criteria by which to decide? (5) How should the rights of local communities and indigenous populations be safeguarded

Trans Adults Amidst the COVID-19 Pandemic: Quality of Life, Pandemic Impact, and Vaccine Preferences

The ongoing COVID-19 pandemic is disproportionately impacting marginalized communities, such as Black, Indigenous, and people of color (BIPOC), disabled individuals, and transgender/nonbinary (i.e., trans) individuals. As trans individuals may be multiply marginalized, it is necessary to examine within group differences among trans individuals of different genders, races, socioeconomic statuses, and abilities. This study examines the following research questions: (1) What is the quality of life of trans adults during the COVID-19 pandemic? (2) How does the self-reported impact of the pandemic vary across groups within the trans community? (3) What preferences do trans adults have regarding receiving a COVID-19 vaccine? Survey data were collected in August/September of 2020. Among a sample of 449 trans adults, findings suggest that the profound impact of the pandemic was not consistent across all community members. Being a woman predicted a higher self-reported impact of the pandemic while being a masc(uline) white respondent tended to predict a lower impact of the pandemic. Higher income was associated with a higher quality of life and being a disabled white respondent predicted a lower quality of life. The majority (99%) of the sample reported wanting to receive a COVID-19 vaccine should one become available. Implications for practice include the importance of considering the holistic experiences of clients and community members, as opposed to having homogenized perspectives of even subsets of the trans community. Future research related to barriers faced when attempting to access a vaccine is needed to inform future public health responses to epidemics/pandemics impacting this community.ECU Open Access Publishing Support Fun

Wind Symphony

Wesley United Methodist Church Thursday Evening April 25, 1996 8:00 p.m

G65.2+5.7: A Thermal Composite Supernova Remnant With a Cool Shell

This paper presents archival ROSAT PSPC observations of the G65.2+5.7 supernova remnant (also known as G65.3+5.7). Little material obscures this remnant and so it was well observed, even at the softest end of ROSAT's bandpass (~0.11 to 0.28 keV). These soft X-ray images reveal the remnant's centrally-filled morphology which, in combination with existing radio frequency observations, places G65.2+5.7 in the thermal composite (mixed morphology) class of supernova remnants. Not only might G65.2+5.7 be the oldest known thermal composite supernova remnant, but owing to its optically revealed cool, dense shell, this remnant supports the proposal that thermal composite supernova remnants lack X-ray bright shells because they have evolved beyond the adiabatic phase. These observations also reveal a slightly extended point source centered on RA = 19h 36m 46s, dec = 30deg 40' 07'' and extending 6.5 arcmin in radius in the band 67 map. The source of this emission has yet to be discovered, as there is no known pulsar at this location.Comment: In AASTEX preprint form, document is 12 pages long and includes 3 figure file