Fuse and switch functions combined within a single housing

Fuswitch provides both switch and fuse functions within a single housing. A mercury capillary is used to alternately vaporize and condense the mercury within a reservoir. The housing is impervious to mercury and the fuse portion of the device operates on the principle of the self-healing mercury fuse

Stably free modules over virtually free groups

Let $F_m$ be the free group on $m$ generators and let $G$ be a finite nilpotent group of non square-free order; we show that for each $m\ge 2$ the integral group ring ${\bf Z}[G\times F_m]$ has infinitely many stably free modules of rank 1.Comment: 9 pages. The final publication is available at http://www.springerlink.com doi:10.1007/s00013-012-0432-

An analysis of the vertical structure equation for arbitrary thermal profiles

The vertical structure equation is a singular Sturm-Liouville problem whose eigenfunctions describe the vertical dependence of the normal modes of the primitive equations linearized about a given thermal profile. The eigenvalues give the equivalent depths of the modes. The spectrum of the vertical structure equation and the appropriateness of various upper boundary conditions, both for arbitrary thermal profiles were studied. The results depend critically upon whether or not the thermal profile is such that the basic state atmosphere is bounded. In the case of a bounded atmosphere it is shown that the spectrum is always totally discrete, regardless of details of the thermal profile. For the barotropic equivalent depth, which corresponds to the lowest eigen value, upper and lower bounds which depend only on the surface temperature and the atmosphere height were obtained. All eigenfunctions are bounded, but always have unbounded first derivatives. It was proved that the commonly invoked upper boundary condition that vertical velocity must vanish as pressure tends to zero, as well as a number of alternative conditions, is well posed. It was concluded that the vertical structure equation always has a totally discrete spectrum under the assumptions implicit in the primitive equations

The Automorphism Group of the Free Algebra of Rank Two

The theorem of Czerniakiewicz and Makar-Limanov, that all the automorphisms of a free algebra of rank two are tame is proved here by showing that the group of these automorphisms is the free product of two groups (amalgamating their intersection), the group of all affine automorphisms and the group of all triangular automorphisms. The method consists in finding a bipolar structure. As a consequence every finite subgroup of automorphisms (in characteristic zero) is shown to be conjugate to a group of linear automorphisms

Scalable Text and Link Analysis with Mixed-Topic Link Models

Many data sets contain rich information about objects, as well as pairwise relations between them. For instance, in networks of websites, scientific papers, and other documents, each node has content consisting of a collection of words, as well as hyperlinks or citations to other nodes. In order to perform inference on such data sets, and make predictions and recommendations, it is useful to have models that are able to capture the processes which generate the text at each node and the links between them. In this paper, we combine classic ideas in topic modeling with a variant of the mixed-membership block model recently developed in the statistical physics community. The resulting model has the advantage that its parameters, including the mixture of topics of each document and the resulting overlapping communities, can be inferred with a simple and scalable expectation-maximization algorithm. We test our model on three data sets, performing unsupervised topic classification and link prediction. For both tasks, our model outperforms several existing state-of-the-art methods, achieving higher accuracy with significantly less computation, analyzing a data set with 1.3 million words and 44 thousand links in a few minutes.Comment: 11 pages, 4 figure

Anisotropic In-Plane Strain and Transport in Epitaxial Nd(0.2)Sr(0.8)MnO(3) Thin Films

The structure, morphology, and electrical properties of epitaxial a-axis oriented thin films of Nd(0.2)Sr(0.8)MnO(3) are reported for thicknesses 10 nm <= t <= 150 nm. Films were grown with both tensile and compressive strain on various substrates. It is found that the elongated crystallographic c-axes of the films remain fully strained to the substrates for all thicknesses in both strain states. Relaxation of the a and b axes is observed for t>= 65 nm with films grown under tensile strain developing uniaxial crack arrays (running along the c axis) due to a highly anisotropic thermal expansion. For the latter films, the room-temperature in-plane electrical resistivity anisotropy, rho_b/rho_c, increases approximately exponentially with increasing film thickness to values of ~1000 in the thickest films studied. Films under tension have their Neel temperatures enhanced by ~25 K independent of thickness, consistent with an enhancement of ferromagnetic exchange along their expanded c axes.Comment: 14 pp., 9 Fig.

A remark on power series rings

A trivializability principle for local rings is described which leads to a form of weak algorithm for local semifirs with a finitely generated maximal ideal whose powers meet in zero

Art Fronts: Visual Culture and Race Politics in the Mid-Twentieth-Century United States

ART FRONTS: VISUAL CULTURE AND RACE POLITICS IN THE MID-TWENTIETH-CENTURY UNITED STATES Erin Park Cohn Supervisor: Kathy Peiss Art Fronts argues that visual culture played a central and understudied role in the African American freedom struggle in the middle part of the twentieth century. In particular, it traces the political lives and cultural productions of a generation of visual artists, both black and white, who seized on the Depression-era ethos of art as a weapon to forge a particular form of visual activism that agitated for social, political, and economic equality for African Americans. Participating in the proliferation of visual culture that characterized early twentieth-century America, the activist artists of this generation took advantage of opportunities to reproduce images widely and thus convey political messages in powerful and immediate ways. Art Fronts traces the careers of these artists from the early days of the Depression, when artists affiliated with the Communist Party first created images in service of African American civil rights, through the Cold War, which limited but did not destroy the links they forged between art and activism. By highlighting changes and continuities in African American cultural politics over the course of four decades, it offers fresh perspectives on the contours of the long civil rights movement. Art Fronts thus participates in recent efforts to challenge the classic narrative of the history of the civil rights movement, yet draws that scholarship in a new direction, pointing to the importance of culture, and particularly visual culture, in all phases of the movement. Indeed, visual artists were highly active in the long civil rights movement, while the images they created and circulated in service of the cause served as a necessary visual forum for a range of competing ideas about the politics of race and civil rights