Frequency decay for Navier-Stokes stationary solutions

We consider stationary Navier-Stokes equations in R 3 with a regular external force and we prove exponential frequency decay of the solutions. Moreover, if the external force is small enough, we give a pointwise exponential frequency decay for such solutions according to the K41 theory. If a damping term is added to the equation, a pointwise decay is obtained without the smallness condition over the force

Universality of Tip Singularity Formation in Freezing Water Drops

A drop of water deposited on a cold plate freezes into an ice drop with a pointy tip. While this phenomenon clearly finds its origin in the expansion of water upon freezing, a quantitative description of the tip singularity has remained elusive. Here we demonstrate how the geometry of the freezing front, determined by heat transfer considerations, is crucial for the tip formation. We perform systematic measurements of the angles of the conical tip, and reveal the dynamics of the solidification front in a Hele-Shaw geometry. It is found that the cone angle is independent of substrate temperature and wetting angle, suggesting a universal, self-similar mechanism that does not depend on the rate of solidification. We propose a model for the freezing front and derive resulting tip angles analytically, in good agreement with observations.Comment: Letter format, 5 pages, 3 figures. Note: authors AGM and ORE contributed equally to the pape

Chile's Neoliberal Health Reform: An Assessment and a Critique

In spite of serious under-financing during the Pinochet years, Chile's public health system remains the backbone of health provision, responsible for the impressive public health status

Substantially Burdened, Substantially in Conflict, or Substantially Unneeded? A Discussion of Abdulhaseeb v. Calbone

El presente proyecto de sistema de información se desarrolló en la Municipalidad Provincial de Contanama - Ucayali con la finalidad de evaluar a la población contamanina la capacidad lectora y así todas las habilidades mentales y psicológicas que presentan la sociedad y demás discapacidades intelectuales y motrices, para que posteriormente con la ayuda de un sistema inteligente ellos puedan potenciar todas las habilidades con las que tienen y a su vez puedan desarrollar nuevas, así pues puedan mejorar su calidad de vida para que puedan tener una participación más activa en la sociedad. Dentro del presente proyecto se encontraran todos los lineamientos necesarios que se usaron para el análisis y desarrollo del mismo, tal es el caso de la metodología PM Book para el desarrollo del análisis respectivo con sus respectivos formatos y estándares. También dentro de este trabajo se detalla el funcionamiento de cada uno de los módulos con los que cuenta el sistema inteligente para que pueda ser más entendible tanto para los usuarios del sistema principalmente y aquellos lectores interesados en el tema. También se podrán encontrar las respectivas conclusiones y apreciaciones finales de quien desarrollo el presente proyecto, así mismo también se podrán encontrar los respectivos anexos y referencias bibliográficas en las que se basó este proyecto

Some Liouville theorems for stationary Navier-Stokes equations in Lebesgue and Morrey spaces

Uniqueness of Leray solutions of the 3D Navier-Stokes equations is a challenging open problem. In this article we will study this problem for the 3D stationary Navier-Stokes equations and under some additional hypotheses, stated in terms of Lebesgue and Morrey spaces, we will show that the trivial solution U = 0 is the unique solution. This type of results are known as Liouville theorems

Lending Booms: Latin America and the World

Recent theories of crisis put lending booms at the root of financial collapses. Yet lending booms may be a natural consequence of economic development and fluctuations. So are lending booms dangerous? In this paper, we investigate empirically this question using a broad sample of lending boom episodes over 40 years, with a special eye for Latin America. Our results indicate that (1) lending booms are often associated with (i) a domestic investment boom; (ii) an increase in domestic interest rates; (iii) a worsening of the current account; (iv) a declines in reserves; (v) a real appreciation; (vi) a decline in output growth, (2) 'typical' lending booms do not increase substantially the vulnerability of the banking sector or the balance of payments. Comparing Latin America and the rest of the world, we find that Latin America lending booms make the economy considerably more volatile and vulnerable to financial and balance of payment crisis.

From starburst to quenching: merger-driven evolution of the star formation regimes in a shell galaxy

Shell galaxies make a class of tidally distorted galaxies, characterised by wide concentric arc(s), extending out to large galactocentric distances with sharp outer edges. Recent observations of young massive star clusters in the prominent outer shell of NGC 474 suggest that such systems host extreme conditions of star formation. In this paper, we present a hydrodynamic simulation of a galaxy merger and its transformation into a shell galaxy. We analyse how the star formation activity evolves with time, location-wise within the system, and what are the physical conditions for star formation. During the interaction, an excess of dense gas appears, triggering a starburst, i.e. an enhanced star formation rate and a reduced depletion time. Star formation coincides with regions of high molecular gas fraction, such as the galactic nucleus, spiral arms, and occasionally the tidal debris during the early stages of the merger. Tidal interactions scatter stars into a stellar spheroid, while the gas cools down and reforms a disc. The morphological transformation after coalescence stabilises the gas and thus quenches star formation, without the need for feedback from an active galactic nucleus. This evolution shows similarities with a compaction scenario for compact quenched spheroids at high-redshift, yet without a long red nugget phase. Shells appear after coalescence, during the quenched phase, implying that they do not host the conditions necessary for in situ star formation. The results suggest that shell-forming mergers might be part of the process of turning blue late-type galaxies into red and dead early-types.Comment: Accepted for publication by MNRAS, 13 page