3,206 research outputs found
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
Damage growth in fibre bundle models with localized load sharing and environmentally-assisted ageing
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
Pengaruh Pemberian Latihan Range of Motion (Rom) Terhadap Kemampuan Motorik Pada Pasien Post Stroke Di RSUD Gambiran
Stroke adalah sindrom klinis berupa gangguan fungsi otak sebagian atau seluruhnya yang diakibatkan oleh gangguan suplai darah ke otak. Stroke dapat berdampak pada berbagai fungsi tubuh diantaranya adalah defisit motorik berupa hemiparese (kelemahan satu sisi tubuh). Penelitian ini bertujuan untuk mengidentifikasi pengaruh latihan Range of Motion terhadap kekuatan otot pasien post stroke di RSUD Gambiran Kediri. Penelitian ini menggunakan desain penelitian Pre Experimental dengan pendekatan Cross Sectional. Populasi dalam penelitian ini sebanyak 17 responden dansampel 16 responden yang diberikan latihan range of motion 2x sehari selama 7 hari. Evaluasi penelitian ini dilakukan pada hari pertama dan ketujuh. Teknik pengambilan sampel, purposive sampling. Analisa data dalam penelitian ini menggunakan analisa univariat dan analisa bivariat (Paired Sample T-test). Hasil penelitian menunjukkan ada pengaruh pemberian latihan range of motion terhadap kemampuan motorik pada pasien post stroke di RSUD Gambiran Kediri 2014. Penelitian ini merekomendasikan perlunya penelitian lebih lanjut dan penggunaan latihan ini sebagai salah satu intervensi mandiri perawat dalam asuhan keperawatan pasien stroke
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