Propagation of boundary-induced discontinuity in stationary radiative transfer

We consider the boundary value problem of the stationary transport equation in the slab domain of general dimensions. In this paper, we discuss the relation between discontinuity of the incoming boundary data and that of the solution to the stationary transport equation. We introduce two conditions posed on the boundary data so that discontinuity of the boundary data propagates along positive characteristic lines as that of the solution to the stationary transport equation. Our analysis does not depend on the celebrated velocity averaging lemma, which is different from previous works. We also introduce an example in two dimensional case which shows that piecewise continuity of the boundary data is not a sufficient condition for the main result.Comment: 15 pages, no figure

Universality class of fiber bundles with strong heterogeneities

We study the effect of strong heterogeneities on the fracture of disordered materials using a fiber bundle model. The bundle is composed of two subsets of fibers, i.e. a fraction 0<\alpha<1 of fibers is unbreakable, while the remaining 1-\alpha fraction is characterized by a distribution of breaking thresholds. Assuming global load sharing, we show analytically that there exists a critical fraction of the components \alpha_c which separates two qualitatively different regimes of the system: below \alpha_c the burst size distribution is a power law with the usual exponent \tau=5/2, while above \alpha_c the exponent switches to a lower value \tau=9/4 and a cutoff function occurs with a diverging characteristic size. Analyzing the macroscopic response of the system we demonstrate that the transition is conditioned to disorder distributions where the constitutive curve has a single maximum and an inflexion point defining a novel universality class of breakdown phenomena

Rupture cascades in a discrete element model of a porous sedimentary rock

We investigate the scaling properties of the sources of crackling noise in a fully-dynamic numerical model of sedimentary rocks subject to uniaxial compression. The model is initiated by filling a cylindrical container with randomly-sized spherical particles which are then connected by breakable beams. Loading at a constant strain rate the cohesive elements fail and the resulting stress transfer produces sudden bursts of correlated failures, directly analogous to the sources of acoustic emissions in real experiments. The source size, energy, and duration can all be quantified for an individual event, and the population analyzed for their scaling properties, including the distribution of waiting times between consecutive events. Despite the non-stationary loading, the results are all characterized by power law distributions over a broad range of scales in agreement with experiments. As failure is approached temporal correlation of events emerge accompanied by spatial clustering.Comment: 5 pages, 4 figure

Fermi surfaces and Luttinger's theorem in paired fermion systems

We discuss ground state properties of a mixture of two fermion species which can bind to form a molecular boson. When the densities of the fermions are unbalanced, one or more Fermi surfaces can appear: we describe the constraints placed by Luttinger's theorem on the volumes enclosed by these surfaces in such Bose-Fermi mixtures. We also discuss the nature of the quantum phase transitions involving changes in the number of Fermi surfaces.Comment: 7 pages with one figure embedded. V2: Minor modifications. Final version as appeared in prin

Creative Contemporary Painting Based on the Iconography of Yeh Pulu Relief

This paper is a report of creative art research under the program of Researching, Creating and Presenting Art of the Research, Technology and Higher Education Ministry of Indonesia. The subject of this research is an iconographic people’s hero of Yeh Pulu relief. This relief is an ancient artifact of Balinese art, located in Bedulu, Gianyar Regency. Visual analysis of the Panofsky’s iconography method (D’alleva, 2005: 22-23) is used as a means of iconography analysis with three aspects: visual/artistic characters, allegories, and symbols. The first-year of the study focuses on analyzing the fundamental visual/artistic approach of my new of contemporary painting series. Deep analysis revealed five findings of visual/artistic approach that explore this theme as the newest visual art concept: cutting (imagining the relief like a poster); smashing (the natural effect of the relief being broken down into many small pieces); drawing (incorporating the visuals of a relief in the method of drawing); highlighting (like a macro camera that presents the profile in its largest and most detailed capacity); coloring (using color to make the visuals impressionistic). The research members are: A. A. Bagus Udayana (photographer), I Nengah Sudika (data collector), and Desi In Diana Sari (layout designer)