2,453 research outputs found
Embedded surfaces of arbitrary genus minimizing the Willmore energy under isoperimetric constraint
The isoperimetric ratio of an embedded surface in is defined as the
ratio of the area of the surface to power three to the squared enclosed volume.
The aim of the present work is to study the minimization of the Willmore energy
under fixed isoperimetric ratio when the underlying abstract surface has fixed
genus . The corresponding problem in the case of spherical surfaces,
i.e. , was recently solved by Schygulla with different methods.Comment: 38 page
“Terrible in its Beauty, Terrible in its Indifference”: Postcolonial Ecocriticism and Sally Mann’s Southern Landscapes
Sally Mann (1951- ) has spent forty years photographing scenes in the American South, including domestic scenes, landscapes, and portraits. Although scholars generally interpret her work as a reflection of the region’s history of violence and oppression, my research will consider her work through the lens of postcolonial ecocriticism. In her art and writing, Mann portrays the land as an indifferent witness to history, a force intertwined with humanity, lending matter for human lives and reclaiming it after death. However, she also describes the way the environment interferes with her the antiquated technology she uses, creating dramatic flaws that imbue the landscapes with emotion absent from the scenes themselves. My research offers new perspectives on Mann’s body of work, especially the way she grants agency to the environment, thereby giving a voice to silent ecologies or silenced histories
The Supreme Court vs. the President: How the Court Decides the Constitutionality of Challenged Presidential Actions
In this presentation, Dr. Laura Wittern-Keller discusses the growth of presidential power through unilateral action—executive orders, proclamations, national security directives, and signing statements—and how the Supreme Court has determined the constitutionality of those actions. The precedent usually used by the Supreme Court stems from a 1952 case that found President Harry Truman’s executive order authorizing the seizure of some American steel mills to be an unconstitutional extension of presidential unilateral action. The case, Youngstown Sheet and Tube v. Sawyer, included a concurrence by Associate Justice Robert Jackson that created a three-part test of presidential orders. That test, modified in 2008, is still good law and will most likely be the test of any future executive orders challenged. The presentation concludes with a discussion of the Guantanamo detainee cases from the George W. Bush administration and a list of executive orders currently being challenged from the Barack Obama administration and the first nine months of the Donald Trump administration
American Catholic Lay Groups and Transatlantic Social Reform in the Progressive Era
Lay Catholic Social Reform Groups Get Their Due
Speak of Progressive Era reform groups and most people will reflexively think of Protestant efforts like settlement houses, charitable aid societies, and temperance crusades. In the Progressive Era, though, Catholic laity also formed active voluntary organizations to work for temperance, rural colonization (resettlement of urban immigrants to rural areas), port programs (assistance for newly arrived immigrants), charitable aid, and urban neighborhood improvement (settlements). The considerable contribution of Catholics to social reform and charitable works has been neglected in much of the scholarly literature about Progressive Era reform groups. Even the literature on temperance advocacy mentions the sizable Catholic Total Abstinence movement only in fleeting references, if at all. Moreover, the few works that have discussed Catholic lay reform efforts have concentrated on single lay groups (Philip Gleason\u27s Conservative Reformers and Christopher Kauffman\u27s Faith and Fraternalism) or a single city (Paula Kane\u27s Separation and Subculture). The 1997 study by Brown and McKeown, The Poor Belong to Us, examines Catholic social reform but focuses on that organized by the Church, not by the laity
A study of homemaker service in the Boston Provident Association January 1, 1940 to December 31, 1942
This item was digitized by the Internet Archive. Thesis (M.S.)--Boston Universit
Optimized Spintronic Terahertz Emitters Based on Epitaxial Grown Fe/Pt Layer Structures
We report on generation of pulsed broadband terahertz radiation utilizing the
inverse spin Hall effect in Fe/Pt bilayers on MgO and sapphire substrates. The
emitter was optimized with respect to layer thickness, growth parameters,
substrates and geometrical arrangement. The experimentally determined optimum
layer thicknesses were in qualitative agreement with simulations of the spin
current induced in the ferromagnetic layer. Our model takes into account
generation of spin polarization, spin diffusion and accumulation in Fe and Pt
and electrical as well as optical properties of the bilayer samples. Using the
device in a counterintuitive orientation a Si lens was attached to increase the
collection efficiency of the emitter. The optimized emitter provided a
bandwidth of up to 8 THz which was mainly limited by the low-temperature-grown
GaAs (LT-GaAS) photoconductive antenna used as detector and the pulse length of
the pump laser. The THz pulse length was as short as 220 fs for a sub 100 fs
pulse length of the 800 nm pump laser. Average pump powers as low as 25 mW (at
a repetition rate of 75 MHz) have been used for terahertz generation. This and
the general performance make the spintronic terahertz emitter compatible with
established emitters based on nonlinear generation methods.Comment: 10 pages, 7 figure
L∞ estimates and integrability by compensation in Besov-Morrey spaces and applications
estimates in the integrability by compensation result of H. Wente fail in dimension larger than two when Sobolev spaces are replaced by the ad-hoc Morrey spaces (in dimension ). However, in this paper we prove that estimates hold in arbitrary dimension when Morrey spaces are replaced by their Littlewood-Paley counterparts: Besov-Morrey spaces. As an application we prove the existence of conservation laws for solutions of elliptic systems of the form where is antisymmetric and both and belong to these Besov-Morrey spaces for which the system is critica
estimates and integrability by compensation in Besov-Morrey spaces and applications
estimates in the integrability by compensation result of H.
Wente fail in dimension larger than two when Sobolev spaces are replaced by the
ad-hoc Morrey spaces. However, in this paper we prove that
estimates hold in arbitrary dimension when Morrey spaces are replaced by their
Littlewood Paley counterparts: Besov-Morrey spaces. As an application we prove
the existence of conservation laws to solution of elliptic systems of the form
where is antisymmetric and both
and belong to these Besov-Morrey spaces for which the
system is critical.Comment: 37 page
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