Effect of Hubbard U on the construction of low energy Hamiltonians for LaMnO_3 via maximally localized Wannier functions

We use maximally localized Wannier functions to construct tight-binding (TB) parameterizations for the e_g bands of LaMnO_3 based on first principles electronic structure calculations. We compare two different ways to represent the relevant bands around the Fermi level: i) a d-p model that includes atomic-like orbitals corresponding to both Mn(d) and O(p) states in the TB basis, and ii) an effective e_g model that includes only two e_g-like Wannier functions per Mn site. We first establish the effect of the Jahn-Teller distortion within the d-p model, and then compare the TB representations for both models obtained from GGA+U calculations with different values of the Hubbard parameter U. We find that in the case of the d-p model the TB parameters are rather independent on the specific value of U, if compared with the mean-field approximation of an appropriate multi-band Hubbard Hamiltonian. In contrast, the U dependence of the TB parameters for the effective e_g model cannot easily be related to a corresponding mean-field Hubbard model, and therefore these parameters depend critically on the specific value of U, and more generally on the specific exchange-correlation functional, used in the electronic structure calculation.Comment: 11 pages, 11 figures, 2 table

Compiling and Editing Calling Out to Yeti: An Anthology of Polish Women Poets

poster abstractWhy read Polish poetry? The Russian Nobel Prize-winning poet Joseph Brodsky many times expressed the view that Polish postwar poetry is the world’s “richest” in both form and content. Two of its poets—Czesław Miłosz in 1980, Wisława Szymborska in 1996—received the Nobel Prize in literature, and a number of others—Zbigniew Herbert, Tadeusz Różewicz and Adam Zagajewski—have achieved international prominence. But the English-speaking world has not yet been able to experience Poland’s poetry fully because of what Benjamin Paloff, editor of the Boston Review, has called the “men’s club” of Polish literature in translation. For example, two recent American anthologies of Polish writers reveal a gender imbalance, with a Trinity University collection (2007) including only three women out of 25 authors, and the Zephyr Press anthology, Carnivorous Bird Carnivorous Boy (2004), only one woman out of 24. In Europe, the situation is no better: in six recent anthologies published in Poland and England, only 15% of the authors were women. This imbalance derives in part from outmoded ideas of what women’s poetry should be and also from crony-driven literary networks that overlook the contributions of women. I take the title of my project from a 1957 poem, “Notes from a Nonexistent Himalayan Expedition,” by Nobel Laureate Wisława Szymborska. In that poem, the speaker attempts to explain her people to the legendary abominable snowman, often interpreted as a stand-in for the intractable Soviet presence in Poland at that time. But in 2012, that idea of “calling out to Yeti” can also be seen as a radical speech act with gendered implications. The English-language anthology of Polish women poets I’m compiling and editing promises to transform how the Anglophone world sees Polish poetry. Scheduled for publication in 2014 by White Pine Press, Calling Out to Yeti will contain eight thematically focused chapters: (1) Lifting the Veils of History; (2) Reimagining the Bard; (3) Ironizing the Art of Poetry; (4) The Domestic Arts; (5) Revisiting Heroes, Monsters, Madwomen and Muses; (6) In the Theater of Dreams; (7) Transitions and Transformations; and (8) Curating Objects. It brings together distinguished poets Wisława Szymborska, Anna Świr, Julia Hartwig, Urszula Kozioł and Ewa Lipska with many talented emerging poets. It shows this group of women poets, 25 in all, working intertextually with each other, across generations, within the larger context of Polish literature, and with writers around the world. I am producing 60% of the translations but have also solicited contributions from renowned translators Stanisław Barańczak and Clare Cavanagh, John and Bogdana Carpenter, Bill Johnston, Czesław Miłosz and Leonard Nathan, and Elżbieta Wójcik-Leese

Demoted to Peninsula

Poetry Contest, Honorable Mentio

Core-shell Structured Composite Silica Micro- and Nanoparticles with Ability Release a De fined Quantity „on Demand“

The aim of this work was the preparation of biocompatible micro- and nanoparticles with a hollow in-terrior. The particles must be able to encapsulate and store a chemical payload for a certain time, followed by the release on demand of this payload. In our previous work [13] we have prepared silica microparticles with a hollow core and found that the diffusion across the mesoporous silica shell was strongly dependent on temperature. In this work, we used this dependence and attached iron oxide nanoparticles on the sur-face of the silica shell to create composite iron oxide/silica particles. The iron oxide nanoparticles were able to heat up in the presence of an alternating magnetic field. This property allowed us to use magnetic field as a tool for remote control of diffusion across the particle shell. To avoid spontaneous leakage of encapsu-lated payload in time, we have modified the surface of the composite micropaticles with a layer of palm oil. Palm oil is a phase change material which is solid under 37 °C. We showed that the resultant composite particles are able to store a payload for several months and release a defined quantity on demand by the application of a magnetic field. The particles were characterised in shape, size, heating ability and their mass transport properties. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3557

The Top Five Kissing Spots in Warsaw, Poland

A list of five recommended kissing locations in Warsaw, Poland, as well as two not recommended locations

Evaluation and Investigation of the Delay in VoIP Networks

The paper is focused mainly on the delay problems, which considerably influence the final quality of connections in VoIP (Voice over IP) networks. The paper provides a detailed exploration of the nature and mechanisms of the delay. The main purpose of the investigation was an attempt to formulate a mathematical model of delay in the VoIP network and its subsequent analysis by laboratory data