bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluating the performance of coupled snow-soil models in
SURFEXv8 to simulate the permafrost thermal regime at a high
Arctic site
Authors: Barrere Mathieu , Domine Florent , Decharme Bertrand , Morin Samuel , Vionnet Vincent , Lafaysse Matthieu
Published: March 2017

Abstract. Global warming projections still suffer from a limited representation of the permafrost-carbon feedback. Predicting the response of the permafrost temperature to climate changes requires accurate simulations of the Arctic snow and soil properties. This study assesses the capacity of the coupled models ISBA-Crocus and ISBA-ES to simulate snow and soil properties at Bylot Island, a high Arctic site. Field measurements complemented with ERA-interim reanalysis were used to drive the models and to evaluate simulation outputs. Snow height, density, temperature, thermal conductivity and thermal resistance are examined to determine the critical variables involved in the soil thermal regime. Simulated soil properties are compared with measurements of thermal conductivity, temperature and water content. The simulated snow density profiles are erroneous, because Crocus and ES do not represent the upward water vapour fluxes generated by the strong temperature gradients within the snowpack. The resulting vertical profiles of thermal conductivity are inverted compared to observations, with high simulated values at the bottom of the snowpack. Still, ISBA-Crocus manages to successfully simulate the soil temperature in winter. Results are satisfactory in summer, but the temperature of the top soil could be better reproduced by representing adequately surface organic layers, i.e. mosses and litter, and in particular their water retention capacity. Transition periods (soil freezing and thawing) are the least well reproduced because the high basal snow thermal conductivity induces too rapid heat transfers between the soil and the snow in simulations. Hence, global climate models should carefully consider Arctic snow thermal properties, and especially the thermal conductivity of the basal snow layer, to perform accurate predictions of the permafrost evolution under climate changes.
Spatiotemporal Variation of Van der Burgh's coefficient in a salt plug estuary
Authors: Shaha Dinesh Chandra , Cho Yang-Ki , Kim Bong Guk , Sony Md. Rafi Afruz , Kundu Sampa Rani , Islam Md. Faruqul
Published: March 2017

Abstract. Saltwater intrusion in estuaries is expected to become a more serious issue around the world due to climate change. Van der Burgh's coefficient, K, is a good proxy for describing the relative contribution of the tide-driven and gravitational components of salt transport in estuaries. However, debate continues over the use of K value for an estuary where K should be constant or spatially varying or a time-independent factor for different river discharge conditions. In addition, whether K functions in an inverse salinity gradient area of a salt plug estuary has not been examined thus far. In this study, we determined K during spring and neap tides in the dry (<30 m−3 s−1) and wet (>750 m−3 s−1) seasons in a salt plug estuary with an exponentially varying width and depth to examine the relative contributions of tidal versus density-driven salt transport mechanisms. High-resolution salinity data were used to determine K. Gravitational circulation (K~0.8) was entirely dominant over tidal dispersion during spring and neap tides in the wet season such that salt transport upstream was effectively reduced, resulting in the estuary remaining in a relatively fresh state. In contrast, during the dry season, K increases gradually seaward and landward (K~0.74) from the salt plug area (K~0.65), similar to an inverse and positive estuary, respectively. As a result, density-induced inverse gravitational circulation between the salt plug and the sea facilitates inverse estuarine circulation. On the other hand, positive estuarine circulation between the salt plug and the river area arose due to density-induced positive gravitational circulation induced by the tide during the dry season, causing the intrusion of high-salinity bottom water upstream. Our results explicitly show that K varies spatially and depends on the river discharge. This result provides a better understanding of the distribution of hydrographic properties as well as the distributions of pollutants, nutrients and biota within large estuaries.
Heterogeneity measures in hydrological frequency analysis: review and new developments
Authors: Requena Ana I. , Chebana Fateh , Ouarda Taha B. M. J.
Published: March 2017

Abstract. Some regional procedures to estimate hydrological quantiles at ungauged sites, such as the index-flood method, require the delineation of homogeneous regions as a basic step for their application. The homogeneity of these delineated regions is usually tested providing a yes/no decision. However, complementary measures that are able to quantify the degree of heterogeneity of a region are needed to compare regions, evaluate the impact of particular sites, and rank the performance of different delineating methods. Well-known existing heterogeneity measures are not well-defined for ranking regions, as they entail drawbacks such as assuming a given probability distribution, providing negative values and being affected by the region size. Therefore, a framework for defining and assessing desirable properties of a heterogeneity measure in the regional hydrological context is needed. In the present study, such a framework is proposed through a four-step procedure based on Monte Carlo simulations. Several heterogeneity measures, some of which commonly known and others which are derived from recent approaches or adapted from other fields, are presented and developed to be assessed. The assumption-free Gini index applied on the at-site L-variation coefficient (L-CV) over a region led to the best results. The measure of the percentage of sites for which the regional L-CV is outside the confidence interval of the at-site L-CV is also found to be relevant, as it leads to more stable results regardless of the regional L-CV value. An illustrative application is also presented for didactical purposes, through which the subjectivity of commonly used criteria to assess the performance of different delineation methods is underlined.
Identification of dominant hydrogeochemical processes for groundwaters in the Algerian Sahara supported by inverse modeling of chemical and isotopic data
Authors: Slimani Rabia , Guendouz Abdelhamid , Trolard Fabienne , Moulla Adnane Souffi , Hamdi-Aïssa Belhadj , Bourrié Guilhem
Published: March 2017

Abstract. Unpublished chemical and isotopic data taken in November 1992 from the three major Saharan aquifers, namely the Continental Intercalaire (CI), the Complexe Terminal (CT) and the phreatic aquifer (Phr), were integrated with original samples in order to chemically and isotopically characterize the largest Saharan aquifer system and investigate the processes through which groundwaters acquire their mineralization. Instead of classical Debye–Hückel extended law, a specific interaction theory (SIT) model, recently incorporated in PHREEQC 3.0, was used. Inverse modeling of hydrochemical data constrained by isotopic data was used here to quantitatively assess the influence of geochemical processes: at depth, the dissolution of salts from the geological formations during upward leakage without evaporation explains the transitions from CI to CT and to a first end member, a cluster of Phr (cluster I); near the surface, the dissolution of salts from sabkhas by rainwater explains another cluster of Phr (cluster II). In every case, secondary precipitation of calcite occurs during dissolution. All Phr waters result from the mixing of these two clusters together with calcite precipitation and ion exchange processes. These processes are quantitatively assessed by the PHREEQC model. Globally, gypsum dissolution and calcite precipitation were found to act as a carbon sink.
Assessment of island beach erosion due to sea level rise: the case of the Aegean archipelago (Eastern Mediterranean)
Authors: Monioudi Isavela N. , Velegrakis Adonis F. , Chatzipavlis Antonis E. , Rigos Anastasios , Karambas Theophanis , Vousdoukas Michalis I. , Hasiotis Thomas , Koukourouvli Nikoletta , Peduzzi Pascal , Manoutsoglou Eva , Poulos Serafim E. , Collins Michael B.
Published: March 2017

Abstract. The present contribution constitutes the first comprehensive attempt to (a) record the spatial characteristics of the beaches of the Aegean archipelago (Greece), a critical resource for both the local and national economy, and (b) provide a rapid assessment of the impacts of the long-term and episodic sea level rise (SLR) under different scenarios. Spatial information and other attributes (e.g., presence of coastal protection works and backshore development) of the beaches of the 58 largest islands of the archipelago were obtained on the basis of remote-sensed images available on the web. Ranges of SLR-induced beach retreats under different morphological, sedimentological and hydrodynamic forcing, and SLR scenarios were estimated using suitable ensembles of cross-shore (1-D) morphodynamic models. These ranges, combined with empirically derived estimations of wave run-up induced flooding, were then compared with the recorded maximum beach widths to provide ranges of retreat/erosion and flooding at the archipelago scale. The spatial information shows that the Aegean pocket beaches may be particularly vulnerable to mean sea level rise (MSLR) and episodic SLRs due to (i) their narrow widths (about 59 % of the beaches have maximum widths < 20 m), (ii) their limited terrestrial sediment supply, (iii) the substantial coastal development and (iv) the limited existing coastal protection. Modeling results indeed project severe impacts under mean and episodic SLRs, which by 2100 could be devastating. For example, under MSLR of 0.5 m – representative concentration pathway (RCP) 4.5 of the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate change (IPCC) – a storm-induced sea level rise of 0.6 m is projected to result in a complete erosion of between 31 and 88 % of all beaches (29–87 % of beaches are currently fronting coastal infrastructure and assets), at least temporarily. Our results suggest a very considerable risk which will require significant effort, financial resources and policies/regulation in order to protect/maintain the critical economic resource of the Aegean archipelago.
Sea ice local surface topography from single-pass satellite InSAR measurements: a feasibility study
Authors: Dierking Wolfgang , Lang Oliver , Busche Thomas
Published: March 2017

Abstract. Quantitative parameters characterizing the sea ice surface topography are needed in geophysical investigations such as studies on atmosphere-ice interactions or sea ice mechanics. Recently, the use of space-borne single-pass interferometric synthetic aperture radar (InSAR) for retrieving the ice surface topography has attracted notice among geophysicists. In this paper the potential of InSAR measurements is examined for several satellite configurations and radar frequencies, considering statistics of heights and widths of ice ridges as well as possible magnitudes of ice drift. It is shown that theoretically surface height variations can be retrieved with relative errors ≤ 0.5 m. In practice, however, the sea ice drift and open water leads may contribute significantly to the measured interferometric phase. Another essential factor is the dependence of the achievable interferometric baseline on the satellite orbit configurations. Possibilities to assess the influence of different factors on the measurement accuracy are demonstrated: signal-to-noise ratio, presence of a snow layer, and the penetration depth into the ice. Practical examples of sea surface height retrievals from bistatic SAR images collected during the TanDEM-X Science Phase are presented.
VISUAL METRIC : guía metodológica para el análisis métrico de materiales audiovisuales
Authors: Paz Enrique Luis Ernesto , Hernández Alfonso Eduardo Alejandro
Published: March 2017

La bibliometría es la especialidad métrica que aplica métodos y modelos a unidades de información. Por el carácter polisémico de la bibliometría puede ser aplicada a cualquier fuente documental. Los materiales audiovisuales por sus características poseen un lenguaje que puede ser descrito a partir del método bibliométrico. No existen metodologías para el análisis métrico de documentos audiovisuales. Se plantean como objetivos del estudio: 1) establecer una guía metodológica para el análisis métrico de materiales audiovisuales y 2) realizar un estudio bibliométrico de los spots de temática medioambiental, producidos por la televisora comunitaria Centro Norte Televisión desde el 2005 hasta el 2016. Para la obtención de resultados se emplean métodos en los niveles teórico y empírico, especialmente el método bibliométrico. Se establece una guía metodológica para el análisis métrico de materiales audiovisuales y se realiza un estudio de caso con el fin de validar la guía propuesta.
A comparison of degree and diploma nursing students confidence of patient safety competency in Ontario, Canada
Authors: Raymond June
Published: March 2017

In Ontario, Canada, Registered Nurses and Practical Nurses practice autonomously and safely in the healthcare system. Students who are aiming to become a Registered Nurse are enrolled in a four-year university baccalaureate degree program while students pursuing a practical nursing diploma are registered in a two or three-year college program. Exploring differences in confidence levels could provide insight into whether one type of nursing educational program is assisting students to develop higher confidence levels on patient safety topics. The Health Professional Education in Patient Survey was used for data collection in this research study. In total, 206 practical nursing students and 458 degree nursing students participated in this study from four different academic settings in Ontario, Canada. Overall, students in both types of educational programs expressed similar levels of confidence on the seven patient safety subscales.  Practical nursing students feel errors are viewed as individual mistakes and they fear repercussions when they make a mistake more so than degree students. Although the categories of students receive different education in terms of length of program, setting, and depth of content, students within either type of program appear to develop confidence levels that are similar for the most part.
Investigation of the Surface Defects in N-Channel MOS Transistors Under Long-Term Low-Dose-Rate Irradiation
Authors: Popov V. D.
Published: March 2017

Gamma-radiation is commonly used to study surface defects in MOS transistors. Early experiments show two stages of surface-defect formation in a MOS structure under low-intensity gamma irradiation (Popov & Vin, 2014; Popov, 2016). On the first stage the defect formation take place on interface Si-SiO2 from the oxide side. This process is described by an exponential dependence (Rashkeev et al., 2002). In the second stage “additional” surface defects are formed from the Si side. Radiation defects of silicon migrated to interface Si-SiO2 from the semiconductor.The goal of this paper is investigation of surface-defect formation in a MOS transistor using the changing of surface electron mobility.
Segurança do Trabalho: ensino, pesquisa e extensão
Authors: Pavani Gilberto João
Published: March 2017

O Brasil ainda se mantém entre os campeões mundiais de acidentes do trabalho, sofrendo o pesado ônus social decorrente de mutilações, incapacitações e óbitos. Assim, cada pessoa que interage com instalações elétricas deve considerar como responsabilidade pessoal conhecer as normas de segurança preconizadas pelo Ministério do Trabalho e Emprego para que sua atuação profissional seja segura, pois a eletricidade escapa aos sentidos, apresentando riscos que são ignorados ou subestimados pelo trabalhador. Neste sentido, os cursos de extensão são uma alternativa viável e necessária, em especial, Norma Regulamentadora no 10 - Segurança em Instalações e Serviços em Eletricidade.
A difusão do cinema brasileiro e o Cine Festival Inconfidentes: o audiovisual verde amarelo conquistando o interior de Minas Gerais
Authors: Rocha Adriano Medeiros , Vaccarini Emmanuelle Dias
Published: March 2017

A partir deste estudo busca-se evidenciar fragmentos significativos da história dos festivais de cinema no Brasil, refletindo sobre sua importância, desenvolvimento e re-significação ao longo dos últimos anos. Neste sentido, a pesquisa se desdobrará também sobre os principais mecanismos de difusão do audiovisual brasileiro contemporâneo. Como estudo de caso, este artigo propõe a análise do Cine Festival Inconfidentes, realizado em Mariana e Ouro Preto por três anos consecutivos, entre 2010 e 2012.
A narrativa cinematográfica: o imbricamento de som e imagem na produção de sentido em “O Céu de Suely”
Authors: Gutemberg Alisson , Lira Bertrand
Published: March 2017

O cinema, como meio de expressão, constitui-se como propagador de uma carga simbólica significativa. E, por isso, configura-se como um dos principais agentes no processo de construção das representações sociais que perpetuam-se dentro dos imaginários coletivos. Para tanto, a narrativa cinematográfica apresenta, em sua estruturação - de acordo com Gaudreault; Jost (2009) -, elementos do domínio do não verbal (a imagem, a música e os ruídos) e do verbal (diálogos e menções escritas). Nos interessa aqui observar como a música se organiza no filme O Céu de Suely (Karim Aïnouz, 2006). E, a partir disso, analisar a maneira como ela atua no contexto da narrativa fílmica, isto é, na produção de sentido dentro do universo diegético.
“Tchau, querida”: leitura do impeachment-revista
Authors: Neto Antonio Fausto
Published: March 2017

Analisa-se nas capas de revistas informativas operações de produção de sentidos sobre o impeachment da presidente Dilma Rousseff, a partir de um duplo trabalho técnico-discursivo: um voltado para sua topografia externa e outro para a sociedade. Apresentam-se como espaço de potencialidades ao falar do “modo de ser” da revista, principalmente de acontecimentos cuja inteligibilidade é gerada por operações que estão em sua economia discursiva. O impeachment da presidente se faz segundo gramáticas e lógicas midiáticas, além de operadores de reconhecimento extraídos e resemantizados de vários tecidos discursivos. As capas vão além de um lugar de exibição da atualidade, operam enunciações manifestando, inclusive, formas de julgamento antecipado.
Verbal processes in English and Spanish: a functional perspective to research articles on discourse analysis
Authors: Rodríguez-Vergara Daniel
Published: March 2017

In this paper we present the results of an analysis of verbal processes and locution constructions in two corpora, one with papers from Anglophone journals, and one from Hispanophone ones. Our main interest was to build up a semantic-grammatical profile of how verbal and locution structures are constructed in the discipline of Discourse Analysis, and see if there were similarities and/or differences in the two corpora. The results  showed  that  there  are  significant  differences  in  terms  of  verbal  process  ratio, metaphoric locutions, most frequent verbal processes, and projection.
Contração ou expansão? Posicionamentos em pareceres de revista científica sob a perspectiva sistemico-funcional
Authors: Cruz Osilene Maria De Sá e Silva da
Published: March 2017

Esta pesquisa analisa pareceres de artigos de uma revista científica de Linguística, com  base  na  perspectiva  Sistêmico-Funcional  (HALLIDAY, 1985,  1994;  HALLIDAY  e MATTHIESSEN, 2004) e no Subsistema Engajamento, do Sistema de Avaliatividade (MARTIN; WHITE, 2005). O corpus é constituído por 67 pareceres de artigo: aprovados sem restrições (A),  aprovados  com restrições  (AR)  e  reprovados  (R).  Foram  identificados  treze  tópicos (aboutness) abordados pelos pareceristas: Análise, Argumentação, Bibliografia, Contribuição, Forma, Língua, Metodologia, Objetivo, Resultado, Resumo, Tema, Teoria e Título. Os resultados revelam predomínio de posicionamentos heteroglóssicos nos três grupos de pareceres, com um  índice  maior  de  posicionamentos  monoglóssicos  no  grupo  de  pareceres  A.  O  grupo  de pareceres AR apresenta mais ocorrências de Expansão Dialógica, sobretudo por significados típicos  da  categoria  Acolhimento.  O  grupo  de  pareceres  R  apresenta  maior  frequência  de Contração Dialógica, predominantemente por recursos da categoria Negação.
A pertinência da utilização do sistema de avaliatividade como referência em pesquisas sobre recepção de livros didáticos : reflexões teóricas e metodológicas
Authors: Silva Renato Caixeta da
Published: March 2017

Apresentam-se  reflexões  sobre  a  pertinência  do  Sistema  de  Avaliatividade como referencial para pesquisas sobre recepção de materiais /livros didáticos por docentes  e  discentes,  considerando  que  esse  sistema  prevê  a  expressão  das  atitudes, gradação  e  engajamento  pelos  falantes.  Também  apresentam-se  questões  acerca  de metodologia e de instrumentos de coleta de informações para pesquisas dessa natureza. O artigo pode contribuir para referendar o Sistema de Avaliatividade como referencial para pesquisas relacionadas ao uso e à recepção de materiais didáticos, podendo tais investigações ser importantes para entendimentos locais e para políticas públicas na área educacional.
Hacia la construcción de la voz crítica de los estudiantes: etapas funcionales y roles de voz en la reseña de divulgación científica
Authors: Ramírez Laura Aurora Hernández
Published: March 2017

Comúnmente se considera que la evaluación ideal del conocimiento en el ámbito escolar es mediante la escritura de una opinión coherente sobre un tema revisado específico. Sin embargo, casi nunca se explica con precisión qué es opinar, ni el proceso por  medio  del  cual  el  discurso  configura  las  opiniones  disciplinares  esperadas.  Como una introducción al análisis discursivo de estas formas disciplinares de la opinión, que representa  una  nueva  veta  de  investigación  dentro  del  análisis  del  discurso,  en  este artículo  mostraré  el  tipo  de  recursos  de posicionamiento autoralutilizados una serie de reseñasde divulgación científica (review) publicadas en la revista ¿cómoves?, editada por la UNAM. Concretamente, describiré los roles de voz(HOOD, 2004; MARTIN; WHITE, 2005; OTEÍZA, 2009) y sus estrategias de apertura y contracción del espacio dialógico con las voces participantes, que se definen en cada una de las etapas de estructura esquemática o secuencias a través de las cuales se cumple la función de recomendar la lectura de un libro relacionado con la ciencia. Para la descripción de estos recursos, empleo el sistema de categorías propuestas por la Teoría de la Valoración, un desarrollo del componente interpersonal que ha despertado gran interés en los investigadores y analistas discursivos de la Lingüística Sistémico Funcional, debido a su gran poder explicativo de la manera en  que  con  el  lenguaje  se  valora  la  experiencia  social  (OTEÍZA,  2009).  Considero  que  a partir de este tipo de descripciones será posible proporcionar respuestas más precisas para las recurrentes interrogantes planteadas acerca de las convenciones de escritura de las diversas comunidades disciplinares y dará pie para la construcción de proyectos de intervención pedagógica de la argumentación especializada.
O lugar do conceito de ideologia na análise do discurso político (ADP): uma proposta à luz da análise crítica do discurso (ACD)
Authors: Souza Vilmar Ferreira de
Published: March 2017

No presente trabalho proponho discutir o lugar do conceito de ideologia na Análise do Discurso Político (ADP), conforme desenvolvido em DeSouza (2011a) e, posteriormente retomado em DeSouza (2011b), ambos ancorados na visão neomarxista de ideologia, que comporta, como uma de suas dimensões basilares, a dimensão discursiva. A base teórica deste trabalho repousa na Gramática Sistêmico-Funcional (HALLIDAY; MATTHIESSEN, 2004) e na Análise Crítica do Discurso (FAIRCLOUGH, 2001). Finalizo este  texto  sugerindo  uma  representação  gráfica  do  conceito  de  ideologia,  bem  como convidando a comunidade acadêmica a inspecionar suas possibilidades investigativas.
Apresentação
Authors: Hendges Graciela Rabuske , Motta-Roth Désirée , Nascimento Roséli Gonçalves do , Heberle Viviane Maria
Published: March 2017

O trabalho não apresenta resumo.
A UTILIZAÇÃO DE SOFTWARES NO ENSINO DE FUNÇÕES QUADRÁTICAS
Authors: Rocha Lúcia Andréia de Souza , Poffal Cristiana Andrade , Meneghetti Cinthya Maria Schneider
Published: March 2017

http://dx.doi.org/10.5902/2179460X14226This article aims to present a different way of teaching quadratic functions concepts. It proposes warm-up and review exercises related to the students’ daily lives. It intends to help teachers during class preparation, as a consequence making learning more pleasurable for the students, demystifying mathematics, providing opportunities of application of several mathematical concepts on the students lives. Using technological tools already available in most Basic Schools, we will present activities using at least one free software to inspire teachers while preparing their lessons and consequently help students build their knowledge.
ATIVIDADES DE GEOMETRIA PARA O ENSINO MÉDIO
Authors: Martinatto Marângela Andrade , Meneghetti Cinthya Maria Schneider , Sperotto Fabíola Aiub
Published: March 2017

http://dx.doi.org/10.5902/2179460X14227This work suggests activities to introduce and develop content for Solid Geometry, particularly prisms and pyramids with High School students, prioritizing the visualization of solids in space, identifying the differences in the shape and characteristics of its elements, without requiring memorization formulas. Also emphasizes the importance of recapitulation of concepts of Plane Geometry. With the passing of years, students have encountered difficulties in mathematics in Middle school and this has a direct consequence on learning of these students in contents related to the High School. To check the veracity of this statement, a survey was conducted through a questionnaire with teachers working with Solid Geometry in seven High Schools in southern State of Rio Grande do Sul. Suggested activities that introduce and complement the contents found in traditional textbooks. Teachers, even with limited resources may use these activities with their students to improve the learning of Solid Geometry in High School.
QUESTIONÁRIO VIRTUAL PARA O ENSINO DE PROBABILIDADE
Authors: Poffal Cristiana Andrade , Jung Maurício Osmall , Meneghetti André , Meneghetti Cinthya Schneider
Published: March 2017

http://dx.doi.org/10.5902/2179460X14232As the concept of probability is fundamental to the individual formation due to its form of reasoning,to its applicability and to the professional field, we present a proposal that suggests, first, a problematization then the definition of the probability jargon. It follows that methodology, since the history occurs in this order: first the problems arise, then the concepts and definitions. So, we use the technology in two virtual and interactive quizzes to be solved by students, since playing has an important role during the constrution of the concepts and definitions, the student becomes easily closer to the whole subject.
UM IRRACIONAL: O NÚMERO DE EULER
Authors: Silva Paulo Leandro Dattori da , Spolaor Silvana De Lourdes Gálio
Published: March 2017

http://dx.doi.org/10.5902/2179460X14244The set of real numbers, R, is a delicate issue to be addressed in the classroom. In particular, the study of the set of irrational numbers is hampered by lack of examples found in many textbooks. The main goal of this paper is presenting of clear manner an important example of irrational number: Euler’s number. Here we present the motivation for the Euler’s number as well, the proof of their irrationality.
ESTUDO DA CIRCUNFERÊNCIA NO ENSINO MÉDIO: SUGESTÕES DE ATIVIDADES COM A UTILIZAÇÃO DO SOFTWARE GEOGEBRA
Authors: Bastos Débora De Oliveira , Poffal Cristiana Andrade , Meneghetti Cinthya Schneider
Published: March 2017

http://dx.doi.org/10.5902/2179460X14252This article proposes three activities that can be developed to study the circle for High School students. All proposed activities use the free software of the dynamic geometry Geogebra as learning tool. The suggested activities have as goal to teach, through instruction scripts, the following content: circle equations (reduced and general), relative position between point and circle and relative position between line and circle. In addition, we will portray an analysis of the activities that based the proposal of our task when these were executed in three Technical Learning Integrated to High School’s third year junior groups. We conclude the validity of the activities by student performance on assessments, showing a better knowledge of the subject in relation to students in classes in which there GeoGebra was not used.
O USO DO GEOGEBRA NO ENSINO DE TRIGONOMETRIA: UMA EXPERIÊNCIA COM ALUNOS DO ENSINO MÉDIO
Authors: Dantas Aleksandre Saraiva
Published: March 2017

http://dx.doi.org/10.5902/2179460X14503This research analyzes if the work with GeoGebra facilitates learning concepts of trigonometry and knowing the perceptions of students about the use of GeoGebra in teaching trigonometry. For this, it makes use of application of assessments and interviews with the students of courses of IFRN. Data analysis shows that, with the use of GeoGebra, students showed more significant learning of several aspects of the behavior of the sine and cosine functions when compared with teaching through lectures with the use of teaching resources more common as book and whiteboard. The students themselves recognized that the use of this software is able to help you better understand the aspects of the behavior of these functions, highlighting the ease of use of GeoGebra and the importance of its use in teaching mathematics. However, for the current and future teachers feel able to work with GeoGebra or any other software, it is essential that the vocational training courses for teachers to develop strategies that ensure effectively the ability to use these tools, the critically and creatively way, and not just another fad that will in no way help improve the teacher’s work and the student’s learning.
CÁLCULO NO ENSINO MÉDIO: UMA ABORDAGEM POSSÍVEL E NECESSÁRIA COM AUXÍLIO DO SOFTWARE GEOGEBRA
Authors: Molon Jaqueline , Figueireo Edson Sidney
Published: March 2017

http://dx.doi.org/10.5902/2179460X14523This article is the result of the dissertation of the Professional Masters in Mathematics in National Network, held in March 2013 at the Federal University of Santa Maria (UFSM). The work aimed to verify the possibility of inclusion in high school, the intuitive ideas of the Differential and Integral Calculus: limits of a function, the average rate of change, instantaneous variation and calculation of areas under the graph of positive functions, limited the x-axis and vertical lines, or even between positive functions in a particular area of the same range. To facilitate the understanding of these ideas, activities were developed using the Software GeoGebra as support learning tool. The activities were applied to an experimental group of students from the first year of High School, combined with the study of quadratic functions. It was found that you can open the horizons within the teaching and learning of mathematics in high school, to the intuitive ideas of calculus. In this work, the objectives of this research will be presented, some proposed activities and the results achieved, and propose developments to deepen and apply the issues discussed here.
MÉTODO PARA RESOLVER EQUAÇÕES DIOFANTINAS COM COEFICIENTES NO CONJUNTO DOS NÚMEROS RACIONAIS
Authors: Savóis Josias Neubert , Freitas Daiane
Published: March 2017

http://dx.doi.org/10.5902/2179460X14529Develop a solid understanding of linear Diophantine equations in two variables facilitates the resolution of many problems of daily life and also the real understanding of some mathematical concepts taught in school but they seem useless and without practical application. Moreover, the relationships that these equations are established with other content that are already inserted into the basic education justify their education and become an important tool for contextualizing and interdisciplinarity. This work also aims to show the importance of teaching of rational numbers and in this context do analysis on a new concept of greatest common divisor,called generalized maximum common divisor, and thus we can use the numberpad as rational coefficients of Diophantine equations, expanding the breadth of problems solved by these equations. The creation of various practical problems of implementation of the theory studied serves to convince us of the importance of this work and to encourage their implementation and creating new problems taking into account the reality of each school and its students.
A SOLUÇÃO DAS QUADRÁTICAS E CÚBICAS NA HISTÓRIA
Authors: Souza Fábio Nicácio
Published: March 2017

http://dx.doi.org/10.5902/2179460X14595For a long time the search to solve equations pushed the brilliant minds in the human History. Arithmetical, geometric and algebraic mechanisms ere developed bringing advance to the mathematics knowledge. A lot of these resources were "simplified" and nowadays they're handled in the classroom overruling among them the algebraic manipulation. This article, gotten from chapter 1 of Math Master dissertation in the PROFMAT Program from UFRPE and named A Geometrical Approach to the cubic Equations shows as from the history of algebra a geometrical manner, not usual anymore, to find the solution to second and third degree equations.
A MATEMÁTICA NO PÔQUER: EXPLORANDO PROBLEMAS DE PROBABILIDADE
Authors: Ehlert Seldomar Jeske , Bellicanta Leandro Sebben
Published: March 2017

http://dx.doi.org/10.5902/2179460X14609This work proposes the use of the poker game as motivation for the study of probability in high school math classes. Along with the basic rules of the Texas Hold’em poker game, a sequence of learning activities involving specific game situations that seek to develop in students the techniques of combinatorics and skills in calculating probabilities of equally likely events is presented.
UMA SOLUÇÃO PARA O PROBLEMA DE FLÁVIO JOSEFO
Authors: Silva Márcia Erondina Souza da , Tonet Luciane Gobbi
Published: March 2017

http://dx.doi.org/10.5902/2179460X14613In this paper, we present a didactic sequence of activities designed for a group of high school students, aged 15-18 years. Our main objective is to study a problem proposed by the mathematician Josephus, around the year 64. Initially, we review some content like numerical sequences, including the special cases of the Arithmetic and Geometric Progressions. Then, we introduce some notions about Recurrence Relations and the Principle of Mathematical Induction, allowing the generalization of some concepts and results which are already known intuitively by the group of students. This article is part of the dissertation entitled A Proposed Approach to Josephus Problem Applied to High School prepared by the student Erondina Marcia D. S. da Silva under the guidance of the Professor Dr. Gobbi Luciane Tonet.
PERMUTAÇÕES, GRUPOS E SIMETRIAS
Authors: Souza Rodrigo Luiz de
Published: March 2017

http://dx.doi.org/10.5902/2179460X14620The main goal this paper is to be a brief introduction to the Group Theory. To begin the study, the concept of permutation was introduced and defined as a bijective function from a group on itself. After that, the concepts of group and subrgroup were exhibited and discussed, as well as their basic properties. Using the concepts discussed so far, the symmetry groups for the equilateral triangle and for the square were presented in order to compare this particular groups with the permutation groups. In the last section of this paper, we sugest a guide to apply the concept discussed here on a High School class.
UMA PROPOSTA AO USO DO WINPLOT NO ENSINO DE FUNÇÕES QUADRÁTICAS NAS TURMAS DO PROEJA
Authors: Dias Rodrigo Carvalho , Kraemer Edson Luiz , Zica César De Oliveira
Published: March 2017

http://dx.doi.org/10.5902/2179460X14622In the light of the difficulties most first-year students at high school face regarding the learning of mathematics contents, this study proposes some activities aiming at teaching square function using the win-plot software as a tool. At the beginning these activities were designed to be applied in the first year of the PROEJA course (a high school course integrated to a technical one for adult learners) at Instituto Federal do Tocantins, however it can be useful for any student who is learning square function. The activities proposed do not intend to replace the formal and algebraic teaching of the subject, yet they aim to offer teachers and students an interesting option to build graphs in an interactive and agile way. Through graph animation tools, we intend to make some relations between the parameters and the behavior of the graph, always presenting the mathematics explanation of the relation observed at the end of the activity.
MATEMÁTICA FINANCEIRA E PLANILHAS ELETRÔNICAS: UMA ABORDAGEM COM A INCORPORAÇÃO DE RECURSOS COMPUTACIONAIS
Authors: Duda Rodrigo , Grossi Luciane
Published: March 2017

http://dx.doi.org/10.5902/2179460X14623This paper has as its goal to propose a new alternative approach to the progressions and financial math teaching, with the incorporation of technological resources. One of the concepts that used is the study of geometric and arithmetic progressions. In order to study those, an approach based on recurrence relations is proposed. With the goal of stimulating the algebraic manipulation and understanding of the financial math formulas variables, it is proposed the incorporation of the technological resources, in particular, of electronic spreadsheets, in classes about the theme. Through the tool, it is proposed the viability of financial math simulators in the classroom, seeking the diversification of activities.
EQUAÇÕES DIOFANTINAS: UM PROJETO PARA A SALA DE AULA E O USO DO GEOGEBRA
Authors: Vansan Alexandre Hungaro
Published: March 2017

http://dx.doi.org/10.5902/2179460X14629The study of Number Theory here in this article aims to study some properties of integer multiples or divisors, emphasizing issues related to divisibility, which will be of great importance for the study of Diophantine equations, which in turn will provide for applications using Geogebra software. The Diophantine equations are algebraic equations that show the solution set of integers, which in this paper we will discuss the Linear Diophantine equations with two unknowns of the form 𝑎 x + 𝑏 y = 𝑐 with 𝑎, 𝑏, 𝑐 integers. In which they are applied as an alternative way for students to find solutions to problems he faced during his school life. This work is intended to further training of teachers who are teaching in the elementary and high school, where you can find suggestions for activities that you can apply in the classroom, or even include in your lesson plan Diophantine equations, since here he will find a suggestion of teaching work plan to include in their classes.
FÓRMULAS RESOLUTIVAS DA EQUAÇÃO QUADRÁTICA E DA EQUAÇÃO CÚBICA SOBRE OS QUATÉRNIOS DE HAMILTON
Authors: Dario Ronie Peterson , Dalaz Gustavo Sanches , Freitas José Roberto
Published: March 2017

http://dx.doi.org/10.5902/2179460X14630We study the resolubility in the Hamilton’s quaternions of quadratic and cubic equations. For the quadratic case, essentially we present more properly known results. We completely developed the Cardano’s Formula for the cubic equation with real coefficients. We also present the solution of the general cubic equation, under a hypothesis on the coefficients.
O SOFTWARE GEOGEBRA: UMA ESTRATÉGIA DE APRENDIZAGEM APLICADA NO ESTUDO DE FUNÇÕES TRIGONOMÉTRICAS
Authors: Maia Joaildo , Pereira Marcelo Gomes
Published: March 2017

http://dx.doi.org/10.5902/2179460X14631This article is based on a clipping from research graduate "stricto sensu" entitled The Education of Trigonometric Functions through Software GeoGebra, job completion to obtain the title of Master Profmat (Professional Master's in mathematics in national network). To this study, we sought to address the weaknesses faced by most students when they were studying trigonometric functions sine and cosine. For this, we proposed the use of software GeoGebra in performing a sequence of activities about the content studied. The research was a qualitative approach, based on observations of the activities performed by the students of 2nd year of high school Federal Institute of Rio Grande do Norte - IFRN - Campus Caicó. The activities enabled check some difficulties encountered by students, well as the interaction between them during the tasks. The results were satisfactory, since they indicate that the use of software contributed to a better understanding of these mathematical concepts studied.
MATEMÁTICA SEM NÚMEROS: UMA INTRODUÇÃO AO ESTUDO DA LÓGICA
Authors: Martins Patricia Rose Gomes de Melo Viol , Souza Josiney Alves de
Published: March 2017

http://dx.doi.org/10.5902/2179460X14634This paper presents a proposal for teaching Logic for the first year of high school. Considering the diversity of students, this study was developed through a sequence of activities to address the weaknesses of interpretation, reasoning and logical reasoning from a false idea that mathematics works only with numbers and accounts. The proposal is to make the activities more meaningful and comprehensive learning for students in which the teacher's role is that of a facilitator and the student constructor of knowledge. Students are invited to take action, seek and express their opinion by giving meaning to their learning, and teachers are suggested to reflect on their experience in the classroom, encouraging and stimulating the search for diversified activities. We conclude by presenting what skills and competencies that will be developed and how they can assist in the development of new mathematical content.
QUADRADOS MÁGICOS: QUANDO O MÉTODO FALHA
Authors: Ichihara José Travassos , Silva Patricia Nunes da , Abreu Renata Cardoso Pires de
Published: March 2017

http://dx.doi.org/10.5902/2179460X14642In this article, we discuss the behavior of the solutions of a system of linear congruences related to the uniform step method. This is a method for constructing magic squares of odd order proposed and mathematically analyzed by Lehmer (1929). His analysis has several steps. In the first, involving the discussion of necessary and sufficient conditions for filling the square, Lehmer says that if two numbers keep a certain relationship to each other, they will be designated to occupy the same cell of the square. We conclude here that numbers that fulfill the mentioned relationship never occupy the same cell. In other words, what Lehmer says is not true.
ESTUDO DE ESTABILIDADE DE EQUAÇÕES DIFERENCIAIS ORDINÁRIAS AUTÔNOMAS E APLICAÇÃO
Authors: Magrini Luciano Aparecido , Gadotti Marta Cilene
Published: March 2017

http://dx.doi.org/10.5902/2179460X14644The aim of this work is to introduce some important results on stability of solutions of autonomous ordinary differential equations and use them in the stability study of a mathematical model of the biological pest control of the sugarcane borer.
EQUAÇÕES DO SEGUNDO GRAU E MUDANÇA DE VARIÁVEIS
Authors: Silva Márcio Vieira da , Pereira Andre Gustavo Campos
Published: March 2017

http://dx.doi.org/10.5902/2179460X14653This article will present part of a Master Thesis (Profmat, 2014), which sought to assist in improving teaching practice math teacher, this practice in recent years ceased to be investigative and also became quite mechanical, it is evident from the study of algebra of elementary school, especially the theme quadratic equations. This theme in most Brazilian textbooks, is approached without any historical context, have two or three solving techniques as well as the student who was unable to learn with ease root extraction and enhancement will be doomed to never be able to determine the roots of such equations, therefore this paper will introduce a change of variable that facilitates the determination of the roots of quadratic equations.
MATERIAIS PEDAGÓGICOS NA PERSPECTIVA DA EDUCAÇÃO MATEMÁTICA CRÍTICA
Authors: Reis Simone Regina dos , Mathias Carmen Vieira
Published: March 2017

http://dx.doi.org/10.5902/2179460X14655Critical research in mathematics education (CME) has pointed out the urgent need to produce educational materials that emphasize real situations experienced by students so that learning becomes more meaningful. To contribute to the research on CME, in this article is presented teaching suggestions to Financial Mathematics (FM) through a pedagogical proposal guided by CME. It is essential that, when applying this proposal, the teacher aims to raise students’ awareness of the importance of the concepts of FM as a tool and to understand the reality in which they operate. The proposed content by pedagogic activities includes the study of concepts of exchange, investments and loans, for students to learn how FM is used socially. Still, this study suggests solving the proposed examples, through spreadsheets, because it offers more features than a calculator.
UM CAMINHO PARA MELHORAR A APRENDIZAGEM EM ANÁLISE COMBINATÓRIA
Authors: Pereira André Gustavo Campos , Bezerra José Rauryson Alves
Published: March 2017

http://dx.doi.org/10.5902/2179460X14659Along its evolution, Humans had to invent counting processes in order to help them in its daily tasks, and the more the society develops, the more is the quantity of things that needed to be counted. Counting techniques were developed to help counting (classifying) such brand new possibilities that were created in that time. Nowadays such techniques are studied at High School, in a subject called Combinatorics. Although such techniques are necessary and useful in practice, it is difficult to teach them not only at High School but also at University. In this paper, desired posture changes in one who tries to solve Combinatorics problems are pointed out and a tool that can dinamize the process of fixing the underlying concepts of this subject is presented.
SISTEMAS DE NUMERAÇÃO: EVOLUÇÃO HISTÓRICA, FUNDAMENTOS E SUGESTÕES PARA O ENSINO
Authors: Rodrigues Aroldo Eduardo Athias , Diniz Hugo Alex
Published: March 2017

http://dx.doi.org/10.5902/2179460X14664Numeral systems allow the representation of numbers, which, together with the forms, constitute the main object of studying of Mathematics. It is also through them that someone can justify the procedures used to perform the four basic arithmetic operations. It is therefore extremely important that the math teacher has a deep understanding of the functioning of numeral systems, in especial, the decimal positional numeral system (DPNS). In this article, we study the properties of numeral systems, in particular those related to the criteria of divisibility and the representation of real numbers in positional systems. We address the topic from three main aspects: its historical evolution; purely mathematical properties of positional numeral systems; and how the teacher can use the two previous aspects in their classes.
ATIVIDADES PARA O ENSINO FUNDAMENTAL E MÉDIO ENVOLVENDO RELAÇÕES DE GIRARD E ARITMÉTICA
Authors: Santos Rosipléia Souza , Almeida Kisnney Emiliano de
Published: March 2017

http://dx.doi.org/10.5902/2179460X14812The objective of this work is to build a didatic proposal for teaching methods to fing the integer or racional roots of polynomials of degree greater than two by using properties of integers learned on the studies of Arithmetic and the relations between coeficients and roots of polynomials known as Relations of Girard, with minimal application of formulas. Thus the student is given the opportunity to exercise simultaneously and dynamically the basics of algebra and arithmetic present in basic education.