Influence of diffractive interactions on cosmic ray air showers

A comparative study of commonly used hadronic collision simulation packages is presented. The characteristics of the products of hadron-nucleus collisions are analyzed from a general perspective, but focusing on their correlation with diffractive processes. One of the purposes of our work is to give quantitative estimations of the impact that different characteristics of the hadronic models have on air shower observables. Several sets of shower simulations using different settings for the parameters controlling the diffractive processes are used to analyze the correlations between diffractivity and shower observables. We find that the relative probability of diffractive processes during the shower development have a non negligible influence over the longitudinal profile as well as the distribution of muons at ground level. The implications on experimental data analysis are discussed

Measurement of Content of 226Ra in Drinking Water From Some States of Mexican Republic by Liquid Scintillation Method

To assess the quality of drinking water in respect to the content of radioactivity, usually is carried out an screening program in the locations of interest, that program consist in pick representative samples of drinking water from the wells in that locations, water samples are analyzed to measuring the gross alpha/beta radioactivity by a low background proportional counter or a liquid scintillation system. When some sample exceeds the normative limit then it must be known which radionuclides are in that sample. Expected radionuclides in water are the NORM (normal occurring radioactive material) from the natural radioactive chains. 226Ra is frequently present in drinking water and is one of most important radionuclide because its “radiotoxicity”, the WHO [World Health Organization, Guidelines for drinking-water Quality, (2016)] recommends a reference level for 226Ra of 1 Bq/L (the dose coefficient for 226Ra is 2.8 x 10-7 Sv/Bq). From a national program of drinking water screening in the Mexican Republic, the samples that exceeded the national normative limits were picked again in the same well and analyzed by LS (liquid Scintillation), using the method of two phases with a not water miscible scintillator cocktail. Results of concentrations of 226Ra from drinking water are presented. In general the content of 226Ra in drinking water samples was lower that the guide values recommended for the WHO

Hegemonia e precariedade acadêmica: a educação universitária no Chile em tempos de Covid 19

Resumen: La emergencia sanitaria ha evidenciado una serie de nudos críticos relacionados con el campo educativo. En este sentido, el cómo se relacionan los sujetos es un aspecto importante a considerar. El presente artículo intenciona la discusión sobre cuáles podrían ser las tensiones que genera la posición de poder de los académicos en una universidad regional. Con el propósito de realizar esta discusión, se analizaron los postulados relativos a la reproducción social de Bourdieu y al concepto de dispositivo de Foucault. Asimismo, se describe la relación hegemónica establecida por algunos académicos y sus posibles efectos en el proceso de enseñanza aprendizaje. El fenómeno descrito, entendido como la hegemonía pedagógica se comporta como un dispositivo de poder basado en el concepto etnocéntrico que posee el rol desempeñado por académicos, docentes de esta institución. Desde una perspectiva anclada en Bourdieu, esta práctica es esencialmente pragmática con características coercitivas las cuales no son evidentes aunque sí son validadas por los sujetos en relaciones intersubjetivas. La negación del habitus de los estudiantes universitarios es ejercido tanto por esta casa de estudio como por quienes ejercen docencia en ella: la institución no ha realizado procesos de revisión, cuestionamiento ni espacios de reflexión tipo claustro para discutir con respecto a la práctica pedagógica frente a la diferencia.Abstract: The pandemic has evidenced a series of problems regarding the educational field. In this sense, how individuals from a specific educational institution relate is a crucial aspect to consider. This article attempts to discuss the stress provoked by the power relations that the academic staff hold at a public university. In order to carry out this pondering, Bourdieu´s views on social reproduction and Focault´s dispositive are analysed. Additionally, the results of these hegemonic practices within the teaching learning process are describedResumo: A emergência sanitária revelou uma série de nós críticos relacionados ao campo educacional. Nesse sentido, a forma como os assuntos se relacionam é um aspecto importante a ser considerado. Este artigo tem como objetivo discutir quais poderiam ser as tensões geradas pela posição de poder dos acadêmicos em uma universidade regional. Com o objetivo de realizar essa discussão, foram analisados os postulados relacionados à reprodução social de Bourdieu e ao conceito de dispositivo de Foucault. Da mesma forma, descreve-se a relação hegemônica estabelecida por alguns acadêmicos e seus possíveis efeitos no processo ensino-aprendizage

Acclimatization to chronic intermittent hypoxia in mine workers: a challenge to mountain medicine in Chile

In the past two decades, Chile has developed intense mining activity in the Andes mountain range, whose altitude is over 4,000 meters above sea level. It is estimated that a workforce population of over 55,000 is exposed to high altitude hypobaric hypoxia. The miners work under shift systems which vary from 4 to 20 days at the worksite followed by rest days at sea level, in a cycle repeated for several years. This Chronic Intermittent Hypoxia (CIH) constitutes an unusual condition for workers involving a series of changes at the physiological, cellular and molecular levels attempting to compensate for the decrease in the environmental partial pressure of oxygen (PO2). The mine worker must become acclimatized to CIH, and consequently undergoes an acute acclimatization process when he reaches the worksite and an acute reverse process when he reaches sea level. We have observed that after a period of 3 to 8 years of CIH exposure workers acclimatize well, and evidence from our studies and those of others indicates that CIH induces acute and chronic multisystem adjustments which are effective in offsetting the reduced availability of oxygen at high altitudes. The aims of this review are to summarize findings of the physiological responses to CIH exposure, highlighting outstanding issues in the field

A [SU(6)]4^4 FLAVOR MODEL WITHOUT MIRROR FERMIONS

We introduce a three family extension of the Pati-Salam model which is anomaly-free and contains in a single irreducible representation the known quarks and leptons without mirror fermions. Assuming that the breaking of the symmetry admits the implementation of the survival hypothesis, we calculate the mass scales using the renormalization group equation. Finally we show that the proton remains perturbatively stable.Comment: Z PHYS. C63, 339 (1994

PRÁCTICAS VIOLENTAS POR GÉNERO EN ESTUDIANTES DE EDUCACIÓN PÚBLICA SUPERIOR

La violencia escolar ha cobrado especial interés en los centros educativos durante los últimos años; profesores, padres de familia y autoridades educativas, han considerado la relación de intimidación, maltrato, o agresiones, ya como una preocupación de carácter social. Las relaciones de dominio-sumisión que se presentan entre pares, donde un agresor(a) busca hacer blanco en otro compañero(a) para hacerlo(a) su víctima produciéndole golpes, rechazos, insultos, con la finalidad de provocarle un daño físico ha incrementado en últimas fechas, sin embargo, conforme los grados escolares avanzan y la edad de los estudiantes se incrementa, la violencia escolar aparentemente disminuye , o bien, sus formas se producen fundamentalmente de manera psico lógica combinada, sobretodo, con la física o la sexual. Las investigaciones realizadas sobre violencia escolar se han enfocado con estudiantes de educación básica (primaria y secundaria) y de educación media superior, en el caso del nivel superior no se encontraron referencias que arrojen datos sobre la situación que impera en México a excepción de Delgadillo, Argüello, González y García (2012). A nivel mundial se han realizado diversas investigaciones que reflejan la realidad del bullying. Olweus comenta que uno de cada siete alumnos en Noruega es víctima o participa en conductas de acoso (16). En investigaciones posteriores, Olweus estima que el 9% de los estudiantes en las escuelas son víctimas o posibles objetivos de violencia escolar (17). Por su parte, Romans refiere que en España, un 40% de los alumnos confiesan sentirse víctimas de la violencia en el contexto escolar (25). En este mismo país, del total de estudiantes de educación secundaria, el 50% perciben problemas de agresión en las aulas y el 11% de ellos, se sienten temeroso s de otro estudiante (5). En el mismo sentido, Ortega, Del Rey, Sánchez, Ortega-Rivera y Genebat refieren que entre el 15 y 35% del alumnado se ve involucrado en actitudes y comportamientos intimidatorios, abuso de po der y exclusión socialEl presente trabajo tuvo como objetivo establecer indicadores cuantitativos obtenidos a partir de un modelo teórico -metodológico que permite evaluar las prácticas violentas entre estudiantes de educación pública superior, se trabajó con 744 estudiantes universitarios, 354 hombres y 388 mujeres; los resultados obtenidos arrojaron valores estadísticos pertinentes, adecuación muestral de Kaise-Meyer-Olkin .940; esfericidad de Bartlett .000; valores de comunalidad superiores a .500; varianza explicada, 44.15%, explicada en 64 reactivos distribuidos en 8 factores; confiabilidad α de Cronbach .946. Indicadores cuantitativos , Factor 1, física-psicológica; Factor 2, desvalorización-control; Factor 3, discriminación; Factor 4, arbitrariedad; Factor 5, indiferencia-desprecio; Factor 6, desaprobación-rechazo; Factor 7, abuso; Factor 8, calumnia. Las medias por grupo según el sexo, arrojaron que, los hombres significativamente presentan más interacciones violentas que las mujeres. Los datos revelan que independientemente del nivel escolar, los varones continúan encabezando los registros de violencia en comparación con las mujeres

A beam-beam monitoring detector for the MPD experiment at NICA

The Multi-Purpose Detector (MPD) is to be installed at the Nuclotron Ion Collider fAcility (NICA) of the Joint Institute for Nuclear Research (JINR). Its main goal is to study the phase diagram of the strongly interacting matter produced in heavy-ion collisions. These studies, while providing insight into the physics of heavy-ion collisions, are relevant for improving our understanding of the evolution of the early Universe and the formation of neutron stars. In order to extend the MPD trigger capabilities, we propose to include a high granularity beam-beam monitoring detector (BE-BE) to provide a level-0 trigger signal with an expected time resolution of 30 ps. This new detector will improve the determination of the reaction plane by the MPD experiment, a key measurement for flow studies that provides physics insight into the early stages of the reaction. In this work, we use simulated Au+Au collisions at NICA energies to show the potential of such a detector to determine the event plane resolution, providing further redundancy to the detectors originally considered for this purpose namely, the Fast Forward Detector (FFD) and the Hadron Calorimeter (HCAL). We also show our results for the time resolution studies of two prototype cells carried out at the T10 beam line at the CERN PS complex.Comment: 16 pages, 12 figures. Updated to published version with added comments and correction