Model for Dissipative Highly Nonlinear Waves in Dry Granular Systems

A model is presented for the characterization of dissipative effects on highly nonlinear waves in one-dimensional dry granular media. The model includes three terms: Hertzian, viscoelastic, and a term proportional to the square of the relative velocity of particles. The model outcomes are confronted with different experiments where the granular system is subject to several constraints for different materials. Excellent qualitative and quantitative agreement between theory and experiments is found.Comment: Link to the Journal: http://prl.aps.org/abstract/PRL/v104/i11/e11800

Corrections to Universal Fluctuations in Correlated Systems: the 2D XY-model

Generalized universality, as recently proposed, postulates a universal non-Gaussian form of the probability density function (PDF) of certain global observables for a wide class of highly correlated systems of finite volume N. Studying the 2D XY -model, we link its validity to renormalization group properties. It would be valid if there were a single dimension 0 operator, but the actual existence of several such operators leads to T-dependent corrections. The PDF is the Fourier transform of the partition function Z(q) of an auxiliary theory which differs by a dimension 0 perturbation with a very small imaginary coefficient iq/N from a theory which is asymptotically free in the infrared. We compute the PDF from a systematic loop expansion of ln Z(q).Comment: To be published in Phys. Rev.

Micromagnetism in (001) magnetite by spin-polarized low-energy electron microscopy

Spin-polarized low-energy electron microscopy was used to image a magnetite crystal with (100) surface orientation. Sets of spin-dependent images of magnetic domain patterns observed in this surface were used to map the direction of the magnetization vector with high spatial and angular resolution. We find that domains are magnetized along the surface [110] directions, and domain wall structures include 90{\deg} and 180{\deg} walls. A type of unusually curved domain walls are interpreted as N\'eel-capped surface terminations of 180{\deg} Bloch walls.Comment: 17 pages, 4 figures. Presented at the LEEM-PEEM 8 conferenc

Non perturbative regularization of one loop integrals at finite temperature

A method devised by the author is used to calculate analytical expressions for one loop integrals at finite temperature. A non-perturbative regularization of the integrals is performed, yielding expressions of non-polynomial nature. A comparison with previuosly published results is presented and the advantages of the present technique are discussed.Comment: 7 pages, 2 figures, 2 tables; corrected some typos and simplified eq. (8

Cuerpo y disciplina, orden y poder: Del Instructor Popular a los Tribunales Infantiles

A fines del siglo XIX, en la República Argentina, el periódico mendocino El Instructor Popular publica el intercambio epistolar entre dos graduados de la Escuela Normal de Paraná: Carlos Norberto Vergara y Ernesto A.Bavio. Reprender, reformar y corregir el error, las faltas y la ignorancia, fueron las justificaciones para hacer uso de punteros y palmetas e incorporar la pena, el dolor y la culpa como correctivos, en las instituciones educativas de "la letra con la sangre entra" en manos de "maestros normales que quieren gobernar con el lático". El espistolario visibiliza y reprueba ciertas prácticas que tuvieron al cuerpo infantil como territorio de anclaje para la institucionalización educativa. Puntear esa conjetura nos permite trazar continuidades y discontinuidades entre los "principios de la disciplina" y "los castigos corporales" como antecedentes para los "tribunales infantiles", implementados en la Escuela Quintana de la Provincia de Mendoza, por Florencia Fossatti, en las primeras décadas del siglo XX.Fil: Alvarado, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; Argentin

Semantic-based policy engineering for autonomic systems

This paper presents some important directions in the use of ontology-based semantics in achieving the vision of Autonomic Communications. We examine the requirements of Autonomic Communication with a focus on the demanding needs of ubiquitous computing environments, with an emphasis on the requirements shared with Autonomic Computing. We observe that ontologies provide a strong mechanism for addressing the heterogeneity in user task requirements, managed resources, services and context. We then present two complimentary approaches that exploit ontology-based knowledge in support of autonomic communications: service-oriented models for policy engineering and dynamic semantic queries using content-based networks. The paper concludes with a discussion of the major research challenges such approaches raise

Control of contacts evaluation and the chemoprophylaxis in the prevention of Tuberculosis, according to the Technical Norm of Health, in the Health Center "El Bosque", La Victoria, Chiclayo - Peru, August - October, 2007

El seguimiento de los contactos y la aplicación de la quimioprofilaxis en la prevención de Tuberculosis según la Norma Técnica para el Control de la Tuberculosis no se sabe si se efectúa adecuadamente en el área de influencia de un Centro de Salud. Con este propósito se realizó el estudio a fin de evaluar el control de contactos y la aplicación de la quimioprofilaxis, según la Norma Técnica de Salud. El estudio es del tipo descriptivo transversal, y los datos se obtuvieron de entrevistas estructuradas a las familias registradas en el Centro de Salud, las cuales poseen una o varias personas con TBC. Se emplearon las fichas familiares para conocer si éstas se encontraban correctamente llenadas, así como un interrogatorio a la jefa del personal de Enfermería encargada del área de salud para saber de qué modo se ha estado llevando la aplicación de la quimioprofilaxis y el control de contactos en la prevención de TBC. Los datos se procesaron en Microsoft Office Excel y se aplicó la prueba estadística de Chi cuadrado independencia de criterios. Se concluye que ninguno de los aspectos en estudio es realizado de acuerdo a lo estipulado en la Norma Técnica para el Control de la Tuberculosis, debido a factores como la falta de información brindada, la ausencia de visitas domiciliarias, la deficiente supervisión; los que serán tratados en el presente documento.Abstract : The follow-up of the contacts and the application of the chemoprophylaxis in the prevention of Tuberculosis according to the Technical Norm for the Control of the Tuberculosis is not known if it is carried out adequately in the area of influence of a Health Center. With this intention the study was realized in order to evaluate the control of contacts and the application of the chemoprophylaxis, according to the Technical Norm of Health. The study is descriptive transverse type, and the information was obtained of interviews constructed to the families registered in the Center of Health, which one or several persons possess with TBC. Familiar cards were used to know if these were filled correctly, as well as an interrogation to the chief of the personnel of nursing in charge of the area of health to know of what way one has been taking the application of the chemoprophylaxis and the control of contacts in TBC's prevention. The information was tried in Microsoft Scullery Excel and there applied to itself the statistical test of square Chi independence of criteria. It concludes that none of the aspects in study is realized in agreement to the stipulated in the Technical Norm for the Control of the Tuberculosis; due to factors as the lack of offered information, the absence of domiciliary visits, the deficient supervision

Distribution of the invasive calanoid copepod <i>Pseudodiaptomus marinus</i> (Sato, 1913) in the Belgian part of the North Sea

The population structure of the non-indigenous calanoid copepod Pseudodiaptomus marinus (Sato, 1913) in the Belgian part of the North Sea (BPNS) is reported for the first time. Detailed P. marinus abundance data including sex and age class of the individuals was gathered on a monthly basis from February 2015 to February 2016 at six sites within the BPNS and Belgian harbors. Relevant environmental variables were analysed to identify potential drivers explaining the population structure of P. marinus within the BPNS. The abundances found were unexpectedly high, with peak densities of up to 560 ± 163 ind.m-3. Even though P. marinus was found in all stations sampled, large spatial and temporal differences were found in the abundance of this species. P. marinus population structure was best explained by water temperature and chlorophyll a concentrations, while salinity and concentrations of dissolved inorganic nitrogen did not influence the distribution. The reported high abundances of the species, especially in the harbor of Zeebrugge, together with the high relative abundances of copepodites indicate that the species is able to reproduce within the BPNS and Belgian harbors, possibly leading to an established, permanent population. It is crucial to study the distribution of this species for a longer period in order to determine the possible establishment of this species in the BPNS and consequences for local planktonic populations