Superconducting gamma-detectors for non-destructive analysis in nuclear safeguards

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, June 2010."June 2010." Cataloged from PDF version of thesis.Includes bibliographical references (p. 41-42).Ultra-high energy resolution superconducting gamma ray detectors operated at temperatures of 0. 1 K can improve the accuracy of non-destructive analysis of nuclear materials. These detectors offer an order of magnitude improvement in resolution over conventional high-purity germanium detectors. The increase in resolution improves the peak-to-background ratio, and reduces errors from line overlap, therefore allowing the identification of weak gamma rays on top of a high Compton background. The higher resolution also improves the accuracy of isotope ratio measurements in fissile material. In order to understand the spectral background and improve the detector sensitivity, GEANT4 Monte Carlo simulations are used to model the low energy response of these superconducting detectors. The models are used to identify the spectral contributions from Compton scattering and from the detector shielding to assess the feasibility of identifying fissile material in spent nuclear fuel. The detector simulations are compared for accuracy to experimental data. We discuss the superconducting detector model, possible improvements in spectrometer configuration, and their use in nuclear safeguards by the IAEA.by Andrea Elizabeth Robles Olson.S.B

A psychological approach in the usage of interests to motivate children to the learning of EFL in a public school of Nuevo León, Mexico.

The present work focuses on 10-year-old children from a public school of Nuevo León, Mexico that have difficulties in the learning of English as a Foreign Language (EFL) and making lesson plans’ adaptations including the students’ interests. The general objective is to examine the relationship between interests and learning of children who show difficulties in the learning process of EFL. The participants in this study are 29 children from a 5th grade primary public school who study English, 2 selected students, one English instructor and one practitioner researcher. The instruments used are based on the concept of triangulation, and the data collection tools are observation forms, interviews, questionnaires about interests and student work. Data analysis from a questionnaire about interests was performed and the main interest categories found were physical activities and videogames. These categories are considered as the thematic content to be used in order to adapt the lesson plans of the EFL classes. The conclusions from the analysis of the students' behaviors and participation during the EFL classes are that the students did not show an improvement during the first class even though it included elements of interest to them, but that changed in the second and third classes. In a scale from 0 to 20 points, it can be observed quantitatively that S1 incremented his participation from 8 in the first class to 15 in the third class, and S2 also incremented his participation from 12 in the first class to 17 in the third class

Complaints about technology as a resource for identity-work

This article examines how people complain about technology. Using discourse analysis, we inspect sixteen hours of video-recorded focus-group interviews and focused one-on-one discussions where technology was topicalized. We investigate these conversations paying attention to (i) features of language and its situated delivery, including emphasis, word choice, metaphor, and categorizations; and (ii) how these accomplish social actions. We show how interactants use narratives of complaint-like activities about hypothetical categories of people and confessions of their own complainable participation to accomplish a ‘bemoaning’ speech act that manages competing affiliations, demands, and disagreements to construct reasonable moral identities in the situated interaction. By engaging in specific micro-level discursive practices in interaction, participants produce and reproduce what new technologies ‘mean’ to them and for contemporary society. This shows how important it is to examine opinions as situated actions rather than as simple facts about what people believe

Between atrote enfuror and a X and 0 game

Essay on two urban performances, the processes of interaction and the act of writing.Ensayo sobre dos performances urbanos, los procesos de interacción y el acto de escritura.Ensaio sobre duas performances urbanas, os processos de interação e o ato de escrever

Aislamiento e identificación fenotípica y genotípica de cepas de Malassezia spp. en pacientes con Pitiriasis versicolor

68 p.Las especies del género Malassezia forman parte de la microbiota normal de la piel, tanto del ser humano como de animales de sangre caliente. La colonización de estas levaduras parece estar influenciada por factores raciales, sexuales y cambios estacionales, con una frecuencia mayor en épocas cálidas y húmedas, pudiendo causar bajo ciertas condiciones infecciones superficiales a la piel.1 Entre las patologías causadas por estas levaduras se encuentran: pitiriasis versicolor, foliculitis y fungemia, y como factor asociado a dermatitis seborreica, dermatitis atópica, psoriasis, papilomatosis reticulada y confluente de Gougerot-Carteaud, pustulosis cefálica neonatal, onicomicosis y otitis externa maligna.2,3,4 Por mucho tiempo se creía que sólo Malassezia furfur era el agente causante de dichas patologías. Los estudios taxonómicos recientes han permitido identificar nuevas especies de Malassezia, reclasificando los agentes etiológicos y demostrado que existen otras especies de Malassezia involucradas.4 En Chile, existen muy pocos estudios y datos que puedan orientar sobre la epidemiología de las dermatomicosis causadas por las especies pertenecientes al género Malassezia, por lo que es interesante establecer el rol que cumplen estas levaduras, en pacientes pertenecientes a la ciudad de Talca, con pitiriasis versicolor

FACTORES ALÉRGICOS Y ALIMENTICIOS QUE INFLUYEN EN EL ASMA EN NIÑOS MENORES DE CINCO AÑOS EN EL HOSPITAL REGIONAL HERMILIO VALDIZAN MEDRANO – HUÁNUCO, 2016

La Presente investigación se realizó con el objetivo de determinar los factores alérgicos y alimenticios que influyen en el asma en niños menores de 5 años en el Hospital Regional Hermilio Valdizan Medrano – Huánuco 2016. El estudio fue de tipo de observacional, prospectivo, transversal, descriptivo con un enfoque cuantitativo. La muestra representativa para el estudio fue de 35 madres de familia de niños menores de 5 años con asma seleccionada con el método del muestreo no probalistico por conveniencia. El instrumento de recolección de datos utilizados fue: la guía de entrevista, para estudiar las características sociodemográficas y un cuestionario para estudiar los factores alérgicos y alimenticios que influyen en el asma. De los cuales, concluyen: un promedio de 68´6% de madres de familia afirmaron que los factores alérgicos influyeron en el asma en niños menores de 5 años, con una prueba de significancia( X2 =9.49 G1=4; P=56.2) un porcentaje promedio de 60% afirmaron que los factores alimenticios influyen en el asma en niños menores de 5 años con una prueba de significancia (X2=12.59 GL=6; P=16.2) un porcentaje general de 65.7% de madres de familia afirmaron que los factores alérgicos y alimenticios influyeron en el asma en niños menores de 5 años, con una prueba de significancia ( X2=36.42 GL=24; P=72.4)Tesi