Computer analysis and design of concrete shell roofs

This paper is a preliminary version of Chapter 3 of a State-of-the-Art Report by the IASS Working Group 5: Concrete Shell Roofs. The intention of this chapter is to set forth for those who intend to design concrete shell roofs information and advice about the selection, verification and utilization of commercial computer tools for analysis and design tasks.The computer analysis and design steps for a concrete shell roof are described. Advice follows on the aspects to be considered in the application of commercial finite element (FE)computer programs to concrete shell analysis, starting with recommendations on how novices can gain confidence and competence in the use of software. To establish vocabulary and provide background references, brief surveys are presented of, first,element types and formulations for shells and, second, challenges presented by advanced analyses of shells. The final section of the chapter indicates what capabilities to seek in selecting commercial FE software for the analysis and design of concrete shell roofs. Brief concluding remarks summarize advice regarding judicious use of computer analysis in design practice

Clima social familiar, hábito de estudio y estrategias de aprendizaje en estudiantes del Colegio Fe y Alegría N° 3 de San Juan de Miraflores, Lima 2016

El objetivo de esta investigación fue determinar la relación entre el clima social familiar, hábito de estudio y estrategias de aprendizaje en estudiantes del Colegio Fe y Alegría Nº 3 de San Juan de Miraflores. Se trata de una investigación no experimental, transversal correlacional no causal. La muestra fue de 85 estudiantes. Como instrumentos se usaron la escala del clima social familiar de R.H. Moos, el inventario de hábitos de estudio de Gilbert Wrenn y la escala de estrategias de aprendizaje de Román y Gallego. Los resultados indicaron que existe relación estadísticamente significativa entre las variables estudiadas. Con un Rho Spearman de 0.7631 entre la variable clima social familiar y hábito de estudio, lo que representa una correlación positiva considerable, un Rho Spearman de 0.7300 entre la variable clima social familiar y estrategias de aprendizaje, lo que representa una correlación positiva media, y un Rho Spearman de 0.7239 entre la variable hábitos de estudio y estrategias de aprendizaje, lo que representa una correlación positiva media. Las implicancias de los resultados han sido discutidas.Universidad Nacional de Educación Enrique Guzmán y ValleTesi

Actitud docente en la enseñanza virtual y relación con el fortalecimiento emocional en estudiantes de un instituto de Huamachuco, 2022

El actual estudio propuso como objetivo general determinar la actitud docente en la enseñanza virtual y relación con el fortalecimiento emocional en estudiantes de un Instituto de Huamachuco, 2022; Es de esta manera que se tiene como propuesta la determinación del objetivo sobre la actitud docente en la enseñanza virtual y relación con el fortalecimiento emocional en estudiantes de un Instituto de Huamachuco, 2022; con base en ello, se propuso como hipótesis la existencia de una correlación de manera directa y significativa entre la actitud docente en la enseñanza virtual y el fortalecimiento emocional en estudiantes de un Instituto de Huamachuco, 2022. Se propuso una investigación de tipo básica, con un enfoque cuantitativo, y teniendo un diseño no experimental de corte transeccional; el cual se complementó con una encuesta para cada variable a modo de instrumento de recolección de datos. Mediante lo que se obtuvo como resultado que, el 84.4% de los encuestados considera un nivel alto relacionado a la actitud del docente y el 52.2% presenta un nivel medio de fortalecimiento emocional. Concluyendo que existe una la actitud docente en la enseñanza virtual se relaciona de manera directa y significativa con el fortalecimiento emocional en estudiantes de un Instituto de Huamachuco, 2022

Relationship between growth traits and yield formation in Indica-type rice crop

Introduction. Climatic variation is one of the causes for the decrease in yield and its variability in Indica-type rice (Oryza sativa L.). This evidences the necessity of the study of the interaction of meteorological variables with the behavior of rice cultivars, to establish the base of management of the harvest and increase of the yield. Objective. The objective of the present study was to relate the yield of rice with variables of plant growth. Materials and methods. Four rice cultivars were planted in the “dry” season of December 2004, February 2005 and January 2006, and in the rainy season of March 2006, April 2008 and 2009, in Los Palacios, Pinar del Río province, Cuba. The yield and its components, the dynamics of plant growth (LAI and dry matter), the variation of the dry matter of the internodes, peduncle, flag leaf, leaf and leaf sheath during the grain filling phase were evaluated the panicle growth in addition to the meteorological data. A multivariate analysis was used to relate the performance to the characteristics of the plants evaluated. Results. The yield was higher in the “dry” season and to obtain higher yields, the growth dynamics of the plant and the variation of the dry matter of the third internode during the grain filling were important. In both seasons, different source-sink relationships were established and these situations depended mainly on the temperature regime at which the plants were subjected. Conclusion. Breeders, in order to increase potencial yields, may fows their atttention in grow traits during vegetative stages

Sistema de control interno en la municipalidad distrital de Pativilca, 2019

El informe de suficiencia: Sistemas de control interno en la municipalidad de Pativilca, 2019, dio respuesta al problema planteado: ¿Se aplica el sistema de control interno en la municipalidad de Pativilca, 2019?, el objetivo planteado fue: Determinar la aplicación del sistema de control interno en la municipalidad de Pativilca, 2019. Este estudio está sustentado en una investigación aplicada de nivel descriptivo, su diseño no experimental: transeccional. La población estuvo conformada por los colaboradores de la municipalidad de Pativilca, en promedio de 42 colaboradores, para la obtención de los datos utilizamos el cuestionario con escala de Likert y el software utilizado para el procesamiento de datos fue el SPSS. Se concluye que solamente el 35.7% del total percibe que, en la municipalidad de Pativilca, está aplicando el sistema de control interno, esto se debe a que la institución no está aplicando de manera adecuada el control previo, el control continuado y el control interno, siendo aspectos muy importantes para el desarrollo eficiente de las actividades de la institución. Se recomienda al alcalde de la municipalidad de Pativilca, realizar un diagnóstico situacional a cerca de las actividades de control que se vienen dando en la institución, eso permitirá identificar las debilidades, tanto en el ámbito del personal, normas y políticas que permiten el cumplimiento de las misas, y hacer los correctivos que sean necesarios para poder superarlos y lograr que las actividades que se desarrollen, buscando la eficiencia y eficacia.Trabajo de Suficiencia Profesiona

Manejo de la maloclusión clase II-1 sin extracciones usando la versatilidad de los elásticos intermaxilares

Reporte de un caso clínico de una paciente femenina de 12 años de edad, quien presentó una clase II esqueletal sin crecimiento, una maloclusión clase II división 1, protrusión y proinclinación de incisivos superiores e inferiores, apiñamiento leve superior e inferior, sobremordida horizontal de 5 mm y sobremordida vertical de 5 mm, línea media maxilar desviada a la derecha. Una forma de arcada maxilar y arcada mandibular parabólica. Los objetivos fueron: mantener el perfil y la clase II esquelética, eliminar el apiñamiento y corregir el eje axial de los dientes, conseguir clase I canina bilateral, mantener la clase I molar bilateral, conseguir adecuada sobremordida vertical y horizontal, centrar la línea media, obtener buen balance y función oclusal. El tratamiento se realizó sin extracciones de primeros premolares superiores y aparatología ortodóntica fija de acuerdo con la técnica de MBT y la versatilidad del uso de los elásticos intermaxilares clase II. La retención utilizada fue removible superior, así como retenedor fijo inferior. Conclusión: La clase II dentaria puede ser corregida con el uso de elásticos intermaxilares clase II.Trabajo académic

Geometrical nonlinear formulation of a Molecular Mechanics model applied to the structural analysis of single-walled carbon nanotubes

In this paper, the post-critical behavior and buckling modes of single-walled carbon nanotubes are analyzed via a Molecular Mechanics model. The main target is to develop a general formulation for the model, which has been simplified under small strains assumption, and to implement a versatile tool for the structural analysis of carbon nanotubes in the framework of geometrical nonlinearity. For this purpose, a mechanical formulation able to reproduce any load configuration and supporting conditions has been derived by using an energy approach. Then, an incremental-iterative solution procedure has been implemented in order to trace several nonlinear equilibrium paths and to obtain the corresponding critical strains of clamped-clamped nanotubes under compressive, flexural and torsional loading distributions. The model shows a good numerical performance and results in agreement with previous atomistic works. Two interatomic potentials have been adopted in order to find out the influence of different constitutive relationships on the final nonlinear response. We have concluded that the choice of the potential function has no significant effect on the final buckling strains. Our results confirm that the final buckling response is strongly determined by geometrical imperfections in the nanotube, which can be well reproduced in the proposed model, but are much more difficult to handle in continuum models. (C) 2015 Published by Elsevier Ltd.Merli Gisbert, R.; Lazaro, C.; Monleón Cremades, S.; Domingo Cabo, A. (2015). Geometrical nonlinear formulation of a Molecular Mechanics model applied to the structural analysis of single-walled carbon nanotubes. International Journal of Solids and Structures. 58:157-177. doi:10.1016/j.ijsolstr.2014.12.028S1571775

Distribuição das Diatomáceas Modernas nos Sedimentos da Baía de Guanabara e Áreas Oceânicas, Rio de Janeiro (Brasil)

One hundred and fifty three superficial sediments were collected in Guanabara Bay to physical-chemistry and diatom analyses in the ambit to Monitoring Project (CENPES/PETROBRAS). A total of 146 taxa of diatoms were identified where the most frequent taxa in Guanabara Bay were Amphora spp., Coscinodiscus spp. and Navicula yarrensis var. yarrensis. These species are potentially harmful that might harm fisheries and mariculture during blooms. The values of ecological indexes like richness and diversity followed the estuarine gradient were the higher values were found in the mouth and de low in the inner part. The multivariate analyzes permitted recognize seven diatom assemblages in the bay. The DCA analyze shows the most influence in the distribution of assemblages were the depth and pH. The diatom assemblages analyze proved to be an efficient tool in the environmental diagnosis of Guanabara Bay.Cento e ciquenta e três amostras de sedimento superficial da Baía de Guanabara foram coletadas durante o Projeto de Monitoramento Ambiental (CENPES/PETROBRAS). Foram identificados 146 táxons de diatomáceas onde as espécies mais abundantes foram Amphora spp., Coscinodiscus spp. e Navicula yarrensis var. yarrensis. Estas espécies identificadas são potencialmente tóxicas e podem prejudicar peixes e a maricultura durante períodos de florescência. Os índices ecológicos de riqueza e diversidade acompanharam o gradiente estuarino sendo maior na entrada da baía e baixos na região interna. As análises multivariadas permitiram reconhecer sete assembléias de diatomáceas na baía. As análises em DCA mostrou que os parâmetros ambientais mais influentes na distribuição das assembléias foram a profundidade e o pH. Os resultados obtidos mostraram que as assembléias de diatomáceas são uma importante ferramenta na caracterização ambiental da Baía de Guanabara

Electrical generator's manufacturing through recycled materials for self-consumption

The reduction of the useful life of some technologies for various reasons currently generates a large amount of electronic waste whose main destination is landfills located in underdeveloped countries. On the other hand, the lack of availability of electrical energy can encourage the use of other less efficient means of generation with a greater environmental impact. To overcome these problems, it is proposed to recover certain wastes in the manufacture of small wind turbines for use in the construction of these countries. This article provides a practical example of the design of the electric machine and its performance in building with the positive social, economic and environmental impact of the regions involved

Movable Structure for a two-axes solar tracker. Tracking a sustainable future

The population growth and development in underdeveloped countries has led to a rise in the demand for energy and the fact that conventional energy sources cause damage to the environment means that the sustainable future must be based on alternative energy sources. This paper describes an application of movable structures for alternative energy sources. We present the design of a movable structure-mechanism for an innovative two-axes solar tracker with a ratio between generated and consumed energy which is less than half the usual one for two-axes trackers. The device has minimum height (minimum environmental impact, easy assembly) and is strong and reliable.Palacios, FJ.; Domingo Cabo, A.; Lazaro, C. (2009). Movable Structure for a two-axes solar tracker. Tracking a sustainable future. Journal of the International Association for Shell and Spatial Structures (IASS). 50(162):163-172. http://hdl.handle.net/10251/620891631725016