bluuebunny/crossref_metadata_2025 huggingface dataset:
Qual o papel que a memória de trabalho exerce na aprendizagem da matemática?
Authors: Corso Luciana Vellinho , Dorneles Beatriz Vargas
Published: May 2012

A memória de trabalho é um sistema cognitivo que apoia o desenvolvimento de várias aprendizagens, entre elas, a matemática. Discute-se, no artigo, se as dificuldades na matemática estão associadas a defasagens em componentes específicos da memória de trabalho, ou estão relacionadas a um déficit geral deste sistema, considerando o modelo de Baddeley e Hicht. Analisa-se a diversidade encontrada nos resultados das pesquisas que relacionam memória de trabalho a dificuldades na matemática, apontando justificativas para tal situação. Define-se o papel da memória de trabalho na aprendizagem da matemática, destacando-se que tal aprendizagem está diretamente ligada a outros processos cognitivos fundamentais para o bom desempenho matemático, como é o caso da velocidade de processamento e da recuperação fluente de fatos aritméticos da memória de longo prazo. O desenvolvimento de mais pesquisas relacionando memória de trabalho a dificuldades na matemática é de fundamental importância, possibilitando avanços nos processos de prevenção e intervenção.
Análisis de un proceso de estudio sobre la enseñanza del límite de una función
Authors: Contreras de la Fuente Ángel , García Armenteros Manuel , Font Moll Vicenç
Published: May 2012

El presente trabajo tiene por objetivo analizar la estructura y funcionamiento de una clase de matemáticas en la que se enseña el límite de una función de una forma intuitiva¹ en el primer curso del Bachillerato². Este análisis se basa en el enfoque ontosemiótico del conocimiento y la instrucción matemática y está pensado para describir, explicar y valorar procesos de estudio matemático en el aula. El principal resultado es llegar a una valoración fundamentada de la idoneidad didáctica del proceso de estudio analizado.
A regra dos sinais para a multiplicação: ponto de encontro com a noção de congruência semântica e o princípio de extensão em matemática
Authors: Moretti Méricles T.
Published: May 2012

A regra dos sinais para a multiplicação é apresentada, sem demonstração, por Diofanto de Alexandria há muito tempo. Somente em 1867 ela é demonstrada por Hankel como, sendo a única que possui a vantagem de satisfazer a distributividade à esquerda e a distributividade à direita. Assim, ele resolve o problema definitivamente do ponto de vista matemático quando usa o princípio de extensão ao prolongar para os números negativos a propriedade da distributividade, há muitos anos utilizada para os positivos. Veremos que a questão do ponto de vista didático se mantém ainda hoje, e apontamos, também, estudos na perspectiva de ensino dessa regra baseada na ideia de congruência semântica e no princípio de extensão em matemática.
A produção científica sobre avaliação educacional e gestão de sistemas e de escolas: o campo da questão entre 2000 e 2008
Authors: Martins Angela Maria , Sousa Sandra Zákia
Published: May 2012

O texto analisa produções acadêmicas que exploram possíveis relações entre gestão escolar e avaliação, com base em dissertações e teses, artigos de periódicos e anais da Associação Nacional de Pós-Graduação e Pesquisa em Educação (Anped) e da Associação Nacional de Política e Administração da Educação (Anpae), totalizando 25 documentos. O foco aqui aprofundado originou-se de Estado da Arte sobre gestão, autonomia e o funcionamento de órgãos colegiados em escolas públicas, que abrangeu o período entre os anos de 2000 a 2008 e reuniu 753 fontes documentais. A partir da identificação de eixos temáticos aglutinadores da produção em pauta, o texto busca explicitar contribuições teórico-metodológicas das pesquisas para compreensão da referida temática, bem como apontar eventuais subsídios para gestores de escolas e de redes. Verificou-se que, embora ainda incipiente, investigações que se dedicam a analisar as relações entre avaliações em larga escala e gestão escolar tendem a aumentar em curto espaço de tempo, tendo em vista a centralidade que o tema vem conquistando nas diretrizes políticas da área da educação.
Gestão estratégica multicultural baseada no Balanced Scorecard em instituições de ensino
Authors: Mizrahi Saul Eliahú , Canen Alberto G.
Published: May 2012

Este artigo apresenta os fundamentos para a construção de uma proposta de gestão estratégica para escolas de Ensino Básico com princípios do Balanced Scorecard em uma abordagem multicultural, consolidando um conjunto integrado de procedimentos e recomendações metodológicas, de modo a promover a valorização da diversidade cultural para o sucesso escolar. Para atingir este objetivo, buscou-se identificar e analisar elementos que facilitam ou dificultam a gestão nesta perspectiva. As vantagens encontradas neste trabalho são seu foco na melhoria institucional, proporcionando maior comunicação entre as partes. Apoia, assim, a realização dos objetivos de democratização da gestão do ensino.
Educação e inclusão social das crianças e dos adolescentes
Authors: Queiroz Amélia Maria Noronha P. de
Published: May 2012

Este artigo trata da inclusão social de crianças e adolescentes, tendo a educação como principal agente de mudança, visando a atingir nível de desenvolvimento humano desejável. Para conhecer a situação atual, foi feita breve análise da legislação referente à criança e ao adolescente no Brasil, assim como dos indicadores de saúde e educação baseados em dados do Ministério da Educação, da Saúde, da Pesquisa Nacional por Amostra de Domicílios (PNAD), do Instituto Brasileiro de Geografia e Estatística (IBGE) e da realidade da relação educação e trabalho. É apresentada proposta de criação de Polos, focando principalmente escolas, postos de saúde e de assistência social já existentes, que seriam definidos num processo democrático sociopolítico, envolvendo Governo e Sociedade. Os protagonistas das ações seriam profissionais de reconhecida competência para desenvolver a proposta, incluindo as funções de monitoramento, acompanhamento e avaliação necessários para maior eficiência e eficácia de suas ações e a quem seriam concedidas condições de trabalho físicas e financeiras compatíveis com sua função, assim como possibilidade de ascensão profissional.
Os mediadores das práticas de letramento de professores em formação inicial
Authors: Guedes-Pinto Ana Lúcia
Published: May 2012

Tomando como base a geração de dados proporcionada pela pesquisa "Formação do professor: processos de retextualização e práticas de letramento", focalizo o processo de apropriação da prática de leitura vivenciado pelos professores em formação inicial. Nas narrativas de memórias sobre suas experiências pessoais da infância, da juventude e da contemporaneidade do curso de Pedagogia, identificamos indícios de como esses sujeitos se inseriram nas práticas de letramento das quais se apropriaram ao longo de seus percursos. Nesse processo de inserção no mundo da escrita, conforme narrado pelos professores, emergem diversos mediadores de suas práticas leitoras. Tendo como referência teórico-metodológica do trabalho de campo a História Oral, os princípios da etnografia e assumindo a abordagem dos Estudos do Letramento e da História Cultural, procuro identificar esses diferentes mediadores e discutir seu papel no percurso de formação do profissional do ensino. Considerando, portanto, a memória de leituras narradas e o que elas nos trazem de conhecimento acerca dos variados personagens que co-protagonizaram suas histórias, busco apontar possibilidades de trabalho com relação à formação de professores.
A intertextualidade na leitura da alfabetizadora
Authors: Santos Cosme Batista dos
Published: May 2012

Este artigo apresenta um estudo dos mecanismos lingüísticos e cognitivos envolvidos na construção da definição da 'intertextualidade' por uma professora alfabetizadora em formação. O pressuposto adotado é o de que a retextualização de textos escritos da ciência e da divulgação científica nos eventos de formação implica em reformulação, apropriação e representação social dos objetos teóricos em função das particularidades do contexto enunciativo. Nessa perspectiva, portanto, a análise de um evento de letramento específico da formação do professor, que visa ao ensino-aprendizagem de conceitos ou de definições teóricas, pode ser orientada pela seguinte questão: quais os mecanismos lingüísticos empregados pelo professor em formação para tornar mais familiares as noções teóricas na Universidade? Desse modo, essa análise pode ser desenvolvida com o intuito de ampliar descobertas anteriores sobre a representação social de termos teóricos realizada pelo professor. Trata-se de uma discussão sobre a participação da oralidade e da experiência na aprendizagem da definição especializada.
A leitura de livros didáticos: uma situação negligenciada
Authors: Bortoni-Ricardo Stella Maris
Published: May 2012

A leitura com compreensão é um problema crucial nas escolas brasileiras. Desde 1985, o Governo Federal adotou uma política de distribuição de livros didáticos a todos os alunos de escolas públicas. Esses livros são publicados por editoras particulares, mas sua seleção segue um cuidadoso processo no âmbito do Ministério da Educação. No entanto, pouca atenção tem sido conferida à compreensão desses livros pelos alunos a quem eles se destinam. Espera-se que qualquer dificuldade em sua compreensão seja sanada pelos professores em sala de aula. Nossa pesquisa recente tem mostrado que de fato os alunos têm muita dificuldade na compreensão dos seus livros didáticos. Este ensaio focaliza estratégias de andaime que professores podem adotar para facilitar para os alunos a leitura com mais proficiência de seus livros didáticos.
"Baseada em evidências": uma análise do discurso de prevenção às doenças
Authors: Schröder Luciane Thomé , Cattelan João Carlos
Published: May 2012

Este artigo analisa o discurso de prevenção às doenças, tendo como foco uma empresa de planos de saúde, a Unimed. O material tomado como base da análise são quatro textos: dois fôlderes, uma mensagem informativa que acompanha o talão de pagamentos e um texto publicado no boletim informativo da empresa. Os conceitos utilizados no estudo provêm da Análise de Discurso e da Retórica (esta última posta sob o viés discursivo).
Sounds of youth in the metropolis: the different routes of the Hip Hop movement in the city of São Paulo.
Authors: Silva José Carlos Gomes da
Published: May 2012

In this article I examine different moments of the hip hop movement in the city of São Paulo. I analyze the intimate relationship of this phenomenon with urban segregation. I first discuss the rise of break dancing in the downtown region in the mid-1980s. I find that the themes and sounds present in the music of this period express aspects of the centrality of public life in the metropolis. In the following decades, there was a shift of hip hop towards peripheral neighborhoods. In this context, I analyze the relationships between rap and a new modality of urban segregation, marked by a withdrawal of the elites into vibrant v.8 n.1 josé carlos gomes da silva fortified enclaves and the transformation of peripheral neighborhoods into “war zones,” controlled by local micro-powers and police violence. At this time, rappers assumed a position as chroniclers of a violent, segregated and silenced urban reality. I also map new cultural productions with a focus on saraus, which are spaces that bring together rap musicians, as well as poets and marginal writers. The frontiers between these groups are increasingly tenuous, many artists have dual affiliation. What unifies them is their reaction to and protest against violence and urban segregation.
The imaginary of Brazilian popular music
Authors: Oliven Ruben George
Published: May 2012

During the early half of the twentieth century there was in Brazil a proliferation of songs which depicted this period’s imaginary. Songs that made up the Brazilian Popular Music (MPB, Música Popular Brasileira) - name given to the ensemble of sambas, chorinhos and Carnival marchas for this period - foregrounded three themes: work, women, and money. Work is rejected, while malandragem is praised. Women are powerful, capable of either encouraging men to accomplish deeds on the streets because they are loved at home, or immobilizing them by betrayal. Money is worth less than love, but it is nonetheless a necessary good. Since it is difficult to earn enough from work, there is, at once, an increasing awareness of the importance of money and the proposal of magical solutions for minimizing its scarcity.
Poetic improvisation in the Brazilian Northeast
Authors: Sautchuk João Miguel
Published: May 2012

This study concerns the singing called repente or cantoria, a modality of improvised sung poetry, practiced in the Northeast region of Brazil. Its practitioners are called repentistas, cantadores or violeiros, and they always sing in duets, alternating in the composition of strophes according to strict parameters of meter, rhyme and thematic coherence. There is a set of rules formulated for this purpose, but the repentistas improvise their verses on a practical basis, such as the poetic rhythm incorporated. The improvisation places the repentista in relation to aesthetic models, such as the rhythm of the poetry, the melodic patterns and the singing rules, at the same time it puts him into a dialogue with the other singer and with the expectations and reactions of the audience. The improvisation, therefore, is not only the poetic vibrant v.8 n.1 joão miguel sautchuk creation, but also the unfolding of a game of interaction between the poets and the other participants in the singing situation.
Modernization and its discontents: discourses on the transformation of caipira into sertanejo music
Authors: Santos Elizete Ignácio dos
Published: May 2012

This paper intends to study how three journalists, while writing about caipira and sertanejo music, managed to articulate conceptions of roots and authenticity in support of a genre that would be considered as a genuinely Brazilian one. Throughout each one’s approach, it’s possible to notice an updating of the myth of three races, through different perceptions of brazil’s discovery and colonization present in social imaginary representations and used in the discourses of several intellectuals. Furthermore there is an analysis of their understanding of the transformations undergone by caipira music since the moment it began to be registered phonographically, from the 1920s up to the nineties. Through this analysis, it’s possible to notice that the vibrant v.8 n.1 elizete ignácio dos santos argument of the modernization undertaken by some heirs of caipira tradition as a process leading to a loss for the genre is not produced without making them assume a ambivalent position in this process.
Gender and musical performance in Maracatus (PE) and Bumba Bois (MA)
Authors: Albernaz Lady Selma Ferreira
Published: May 2012

This article seeks to answer the following questions: What instruments are played by men and women in Maracatu (Pernambuco) and Bumba Meu Boi (Maranhão)? What are men’s and women’s participation in singing and in music composition? Which meanings and values give support to these practices, and how do they relate to the meaning and value of the music in the two cultural manifestations? The research is based on fieldwork conducted in Recife-PE and São Luís-MA in 2009/10 as well as research carried out in previous years. The conclusion reached was that musical performance, especially instruments and singing, classified as masculine and feminine, shapes and orients men’s and women’s social insertions, contributing to the organization and forms of presentation of Groups vibrant v.8 n.1 lady selma f. albernaz of Maracatu and Bumba Meu Boi. Hierarchies are produced to justify differentiated powers, which lend support to gender inequalities.
Music from the Forest: on 'culture' among the Xokleng
Authors: Hoffmann Kaio Domingues
Published: May 2012

This text reflects on some of the meanings denoted by forest music in the Xokleng universe, focusing in particular on the dimensions of ‘culture,’ politics and mythic time. With this aim in mind, the text briefly describes some of the native conceptions of both this music and the rituals during which it is performed. The progressive transformation enabled by the mythic episode of leaving the forest and the contemporary appropriations of its indexes (appropriations which the group’s ethics and aesthetics hold to be adequate) form the empirical basis for the way in which this music is perceived by the indigenous people concerned.
Damascus in Dahlem art and nature in burle Marx' tropical landscape design
Authors: Duarte Luiz Fernando Dias
Published: May 2012

One of the main features of Burle Marx’s biography is the idea that he discovered the aesthetic qualities of tropical flora that came to characterize his famous new approach to landscape design during a juvenile visit to Berlin-Dahlem Botanical Gardens, in the 1920s. Having been born [1909] in São Paulo, he is supposed not to have had previous contact with tropical spontaneous richness, thanks to the Europeanized taste that prevailed there. As any young member of the local elites with a disposition towards an artistic career, his family trip to Europe was an essential condition for close contact with the avant-garde tendencies of early 20th century. Ever since the 19th century, that pattern of contact of Brazilian prospective artists with ‘civilization’ had entailed the emergence of different trends of ‘nativist’ renderings of metropolitan taste. In such a context, the peculiar aspect of RBM’s European début was the ‘discovery’ of tropical nature and not only that of the formal, ‘universal’ language of high culture. The discussion of what is involved in this game of mirrors is the aim of this paper.
USA & Brazil in gantois power and the transnational origin of Afro-Brazilian studies
Authors: Sansone Livio
Published: May 2012

Between 1941 and 1943 the city of Salvador, Bahia became the site of the battle between two different perceptions of black integration in the United States and of the place of Africa in this process. Franklin Frazier, the most famous black sociologist of the time, was locked into an argument with the equally famous, white, and Jewish anthropologist Melville Herskovits on the “origins” of the so-called black family. To make things even more complex, both centered their contention on fieldwork done among the same informants: the povo de santo (the members) of the same candomblé house of worship in Salvador. In between the two of them was linguist Lorenzo vibrant v.8 n.1 livio sansone Dow Turner. The article shows how transnational was the making of Afro- Brazilian studies and how important is a critical assessment of power relations in this international field of studies.
Your ID, please? the Henry Gates vs. James Crowley event from an anthropological perspective
Authors: Peirano Mariza
Published: May 2012

In the modern world, ID papers are those indispensable objects without which we cannot prove we are who we say we are. We need material proof to attest to our identification. The central ethnographic event of this paper took place in July 2009 with the arrest of Professor Henry Louis Gates, Jr. by the police of the city of Cambridge, Massachusetts, after a passer-by reported that someone was breaking of the entrance door of a house which, it soon transpired, was the professor's own house. From the analysis of this episode three mechanisms of classification and singularization are revealed, namely "recognition," "identification," and "profiling."
Perspectives théoriques dans l'étude de la famille, de l'enfance et de la parenté: un regard à partir de la comparaison entre adoption et P.M.A.
Authors: Allebrandt Débora
Published: May 2012

Famille et parenté sont des sujets très chers à l'anthropologie. Cet article met en relief les changements et questions ontologiques ayant orienté ce domaine tout au long des années. D'un point de vue historique, nous revisitons tout ce qui va des perspectives théoriques classiques aux outils contemporains qui ont guidé cette discipline vers les nouvelles réalités ayant transformé la famille, la parenté et la parentalité. Notre regard se porte sur la comparaison entre adoption et procréation médicalement assistée pour mettre em relief les contributions permettant une meilleure compréhension des relations complexes constituant la famille d'aujourd'hui.
The de-kinning of birthmothers: reflections on maternity and being human
Authors: Fonseca Claudia
Published: May 2012

Bringing together different strands of social analysis - the work on violence and subjectivity, legal anthropology and studies on kinship practices -, I propose in this article to treat a woman's giving away her child as a form of social suffering. Rather than focusing on the more spectacular phenomenon of "traffic" and "abduction" of children, I approach the "everyday violence" in adoption practices. In particular, I propose to demonstrate how legal plenary adoption emerges as a form of state-organized bureaucratic violence that "further burdens experience". Following this line of reasoning, I investigate the "de-kinning" of birthmothers, i.e., the institutionalized effort that goes into undoing the naturalized category of biological motherhood. However, my major question, treated in the second half of this text, will be: how is this process experienced by those most involved? Altogether, my purpose here is to follow through on situations in which the analysis of discourse and practice reveal the ambivalences of social experience, introducing new elements into policy debates, and enlarging on the creative possibilities of kinship's "plasticity".
From socio-politics to kinship dynamics among the Kaingang
Authors: Rocha Cinthia Creatini da
Published: May 2012

This article is based on ethnographic data on the social and political organization of a Kaingang collective that is currently requesting the demarcation of the Terra Indígena Sêgu [Sêgu Indigenous Land] (in Rio Grande do Sul State in southern Brazil). Ethnographic data observed in various indigenous Kaingang lands in southern Brazil point to an intricate and rhizomatic network of social relations within and between groups and families, which, beyond their locations of origin or residence, articulate socio-cosmic-political principles that mark distinct processes of reciprocities and divisions. Here, the movement for land claims and internal tensions within the collectives either result in distancings or approximations that are translated into principles of inclusion or exclusion of individuals and groups in relation to territories that are already occupied and or being claimed. Thus, if for non-Kaingang the Kaingang- as for other Amerindian populations - project an ethnic identity based on the idea of a generalized kinship, at the level of their intra- and inter-group relations, the fluidity with which the ties among those who are considered relatives (kanhkó) or not, can be easily made or unmade, strengthened or broken.
Pós-dradiviano Sateré-Mawé: parentesco y rituales de afinabiliadad
Authors: Alvarez Gabriel O.
Published: May 2012

El material etnográfico Sateré-Mawé fue analizado por la perspectiva de diferentes tradiciones teóricas de antropología del parentesco. El análisis del sistema de parentesco Sateré-Mawé permite cubrir un vacío bibliográfico acerca de la temática y también será la puerta de acceso que permitirá trascender el ámbito de los términos de parentesco para la comprehensión de la alteridad. Las conclusiones teóricas en el campo del parentesco, permiten una interpretación del ritual de la tucandira, que muestra como el ritual transforma performáticamente la afinidad virtual en afinidad potencial y los afines potenciales en afines efectivos. A partir del análisis del parentesco y el ritual, proponemos interpretar el ritual de la Tucandira, como una institución que ordena la circulación de mujeres de forma tan eficaz como otras instituciones clásicas del parentesco como el casamiento entre primos cruzados y los sistemas dradivianos.
Architecture inside out: urban transformations through the perception of demolition engineers
Authors: Goyena Alberto
Published: May 2012

The present article is an ethnographic journey into the universe of techniques and rituals undertaken by companies geared to the demolition of architectural constructions. Viewed by many, more often than not, as merely brutal and even outrageous, the task of destroying is herein discussed in its material and symbolic complexity. Just as the act of building assumes a way of understanding and qualifying space in accordance with a set of social norms, the act of demolishing is, in and of itself, ruled by beliefs and cosmologies that vary a great deal from one context to the other. It will be suggested that the destroyer of walls and his sledgehammer may just as well unveil “history” and “heritage”, hidden in the midst of bricks, that even the most seasoned preservationist would not have even dreamt possible.
Circulating Tumor Cell Count Is a Prognostic Factor in Metastatic Colorectal Cancer Patients Receiving First-Line Chemotherapy Plus Bevacizumab: A Spanish Cooperative Group for the Treatment of Digestive Tumors Study
Authors: Sastre Javier , Maestro M. Luisa , Gómez-España Auxiliadora , Rivera Fernando , Valladares Manuel , Massuti Bartomeu , Benavides Manuel , Gallén Manuel , Marcuello Eugenio , Abad Albert , Arrivi Antonio , Fernández-Martos Carlos , González Encarnación , Tabernero Josep M. , Vidaurreta Marta , Aranda Enrique , Díaz-Rubio Eduardo
Published: May 2012

Background.

The Maintenance in Colorectal Cancer trial was a phase III study to assess maintenance therapy with single-agent bevacizumab versus bevacizumab plus chemotherapy in patients with metastatic colorectal cancer. An ancillary study was conducted to evaluate the circulating tumor cell (CTC) count as a prognostic and/or predictive marker for efficacy endpoints.

Patients and Methods.

One hundred eighty patients were included. Blood samples were obtained at baseline and after three cycles. CTC enumeration was carried out using the CellSearch® System (Veridex LLC, Raritan, NJ). Computed tomography scans were performed at cycle 3 and 6 and every 12 weeks thereafter for tumor response assessment.

Results.

The median progression-free survival (PFS) interval for patients with a CTC count ≥3 at baseline was 7.8 months, versus the 12.0 months achieved by patients with a CTC count <3 (p = .0002). The median overall survival (OS) time was 17.7 months for patients with a CTC count ≥3, compared with 25.1 months for patients with a lower count (p = .0059). After three cycles, the median PFS interval for patients with a low CTC count was 10.8 months, significantly longer than the 7.5 months for patients with a high CTC count (p = .005). The median OS time for patients with a CTC count <3 was significantly longer than for patients with a CTC count ≥3, 25.1 months versus 16.2 months, respectively (p = .0095).

Conclusions.

The CTC count is a strong prognostic factor for PFS and OS outcomes in metastatic colorectal cancer patients.
A framework for valuing the human dimensions of engineered systems
Authors: Simm Jonathan D.
Published: May 2012

As well as safely delivering their basic functions, ethical considerations suggest that sustainably engineered systems should wherever possible offer related amenity and aesthetic value and be socially connected to the communities they serve. Given the evident gap in assessment tools in this area, semi-structured interviews and case study work have been conducted with engineering practitioners in the field of flood and coastal risk management and with community members and activists, to identify a way in which these human dimensions of existing engineered structures and systems might be assessed and scored/ranked in a manner consistent with their technical assessment. The approach is founded on a trinitarian framework of order/security, belonging/justice and imagination/inspiration which reflects both Vitruvius’ original architectural principles (strength, utility and beauty) and insights drawn from key thinkers from a wide range of disciplines. Ideas and concerns about the practical assessment and delivery of human dimensions within the framework are discussed.
Stiffness at small strain: research and practice
Authors: CLAYTON C.R.I.
Published: May 2012

This paper provides the background to the 50th Rankine Lecture. It considers the growth in emphasis of the prediction of ground displacements during design in the past two decades of the 20th century, as a result of the lessons learnt from field observations. The historical development of the theory of elasticity is then described, as are the constitutive frameworks within which it has been proposed that geotechnical predictions of deformation should be carried out. Factors affecting the stiffness of soils and weak rocks are reviewed, and the results of a numerical experiment, assessing the impact of a number of stiffness parameters on the displacements around a retaining structure, are described. Some field and laboratory methods of obtaining stiffness parameters are considered and critically discussed, and the paper concludes with a suggested strategy for the measurement and integration of stiffness data, and the developments necessary to improve the existing state of the art.
Modelling the dynamic embedment of seabed pipelines
Authors: CHEUK C.Y. , WHITE D.J.
Published: May 2012

The as-laid embedment of a seabed pipeline is an important design parameter. As a pipe is laid on the seabed it oscillates, owing to vessel motion and hydrodynamic loading of the hanging pipe. This movement significantly increases the pipe embedment beyond the theoretical value related to the static pipe weight, even when corrected for any stress concentration caused by the hanging catenary. Dynamic lay effects are either ignored in practice, or are accounted for by scaling up the static embedment by an empirical factor, leading to significant uncertainty in this important design parameter. A series of centrifuge model tests has been conducted using two clays – kaolin and a high-plasticity natural clay – to simulate the dynamic embedment process. The results indicate that only a few cycles of small-amplitude oscillation (±0·05D) are required to double or triple the pipe embedment, owing to the combined effect of lateral ploughing and soil softening. In these experiments the pipe embedment increased to up to eight times the static embedment after 100 cycles of motion, which represents a typical lay process. A model is proposed for the cycle-by-cycle embedment of a pipeline under a given sequence of small-amplitude oscillations at a given applied vertical force. The trajectory of the pipe movement is assessed using a flow rule derived from plasticity-based yield envelopes. The effect of soil remoulding is explicitly captured by linking the accumulated disturbance to the decay in soil strength. Using input parameters derived from theoretical considerations and T-bar penetrometer tests, the model captures the essential features of the dynamic embedment process. With modest optimisation of the model parameters, the mean discrepancy between the calculated and measured embedment is only 12% for both clays. The ultimate states predicted by this cycle-by-cycle model also provide a rough estimate of the maximum pipe embedment for fully remoulded conditions, which include some degree of water entrainment caused by the lay process, evident in the optimised parameters. This ultimate embedment is governed by the remoulded soil strength and the pipe weight (augmented by any stress concentration). The amplitude of the cyclic motion affects the rate of softening, and hence the rate of settlement. This model provides a framework for assessing the as-laid embedment of seabed pipelines on a more rigorous basis than current practice.
Traitement par l’EMDR d’états comorbides d’ESPT et de dépendance à l’alcool : un exemple de cas
Authors: Abel Nancy J. , O’Brien John M.
Published: May 2012

L’EMDR (désensibilisation et retraitement par les mouvements oculaires) est une thérapie qui a démontré son efficacité dans le traitement de l’état de stress post-traumatique (ESPT). Une littérature clinique encore relativement réduite, mais croissante, montre que l’EMDR peut aussi être un traitement complémentaire efficace de la toxicomanie. Le présent article passe en revue les divers protocoles qui ont été développés dans ce but, avec les protocoles de Vogelmann-Sine et al., Omaha, Popky et Hase. Une étude de cas intégrant certaines de ces interventions est présentée afin d’illustrer la réussite du traitement par l’EMDR d’une femme souffrant de longue date d’une dépendance à l’alcool et d’un ESPT comorbides. Le suivi, deux ans plus tard, a montré que cette femme restait sobre et que l’ESPT était en rémission complète. Après une discussion des aspects importants de ce cas, les auteurs explorent de futures directions de recherche.
Le protocole EMDR pour les incidents critiques récents : application à un contexte de continuum de soins en santé mentale après une catastrophe
Authors: Jarero Ignacio , Artigas Lucina , Luber Marilyn
Published: May 2012

Cette étude de terrain randomisée et contrôlée a été réalisée après un séisme de 7,2 en Basse-Californie au Mexique. Le traitement a été offert selon les principes du continuum de soins. Un briefing de gestion de crise a été proposé à 53 individus Ensuite, les 18 individus qui avaient obtenu des scores élevés sur l’échelle IES (Impact of Event Scale : échelle d’impact des événements) ont bénéficié du protocole EMDR pour les incidents critiques récents (EMDR-PRECI: EMDR Protocol for Recent Critical Events), un protocole EMDR modifié à séance unique qui a été élaboré pour le traitement des traumatismes récents. Les participants ont été assignés de manière aléatoire à deux groupes : le groupe de traitement immédiat et le groupe de de traitement retardé/liste d’attente. Il n’y a pas eu d’amélioration dans le groupe de liste d’attente ; les scores des participants du groupe de traitement immédiat se sont significativement améliorés en comparaison avec les participants du groupe de liste d’attente. Une séance de EMDR-PRECI a produit une amélioration significative des symptômes de stress post-traumatique tant pour le groupe de traitement immédiat que pour le groupe de traitement retardé/de liste d’attente, avec des résultats maintenus lors du suivi après 12 semaines, alors que des séismes d’après-choc effrayants continuaient à survenir fréquemment. Cette étude apporte des preuves préliminaires en faveur de l’efficacité de ce protocole dans un contexte de continuum de soins en santé mentale après une catastrophe. Des études contrôlées supplémentaires sont souhaitées afin d’approfondir l’évaluation de l’efficacité de cette intervention.
A Successful Remoaval Inorganic Hard Scale Deposits in an Offshore Pipeline in Gemsa Oil field, Egypt: Field Study
Authors: Bakr M. , Abdel Hay A. , Hamdy E.
Published: May 2012

Water flooding is the hinge pin for Gemsa Oil Field. Water injection is supplied from shallow water supply wells. Compatibility tests had indicated probable deposition of calcium sulphate scale on surface and subsurface production equipment. Calcium sulphate scale has been recognized to be a major operational problem. The bad consequences of scale formation comprised the contribution to flow restriction thus resulting in oil and gas production decrease. The nature of calcium sulphate scale is very hard and can't be dissolved with known dissolver. Sister companies that has similar problem were always going to the mechanical remover options.

Extensive lab and field work was conducted to determine the suitable chemicals to dissolve calcium sulphate scale. This paper describes the development and field application of chemical treatment to remove scale in an offshore 8" production line in Gemsa oil field. Continuous precipitation of calcium sulphate scale caused partial plugging of the pipeline. This partial plugging created a back pressure on production wells which decreased the productivity. The field production has been decreased to almost one tenth of the normal field production level(1).

A thorough investigation was conducted to identify the composition and location of the scale, in order to recommend a suitable chemical to remove the scale, and to assess the effectiveness of the treatment method in the field.

Based on extensive lab studies, SAG-01 was tested and applied in production line to remove the scale efficiently, the program was designed taking into consideration the nature of the scale. The treatment program included three - staged process: The use of an organic solventThe main treatment (SAG-01).The post flush stage (injection water),

The job results were outstanding, where as 1-Production increased by about 2,000 BOPD2-Launcher pressure dropped by about 350 psi.3-Decrease the back pressure on our producing wells.4-Additional producing wells into production.5-Efficient cost /Bbl.
Novel Scale Squeeze Technology and Treatment Designs for Improving Scale Inhibitor Retention and Treatment Lifetimes - Use of Ionic Polymers in the Overflush
Authors: Heath Steve , Juliussen Bjorn , Chen Ping , Chen Tao , Benvie Ronald
Published: May 2012

A common method to prevent scale forming in oil production wells is to inject scale inhibitor into the formation in so called squeeze treatments. Conventional scale inhibitor treatments with a brine pre-flush, main scale inhibitor pill and brine over flush stages are often not considered to be economically efficient as a large proportion of the scale inhibitor introduced into the squeeze treatment is returned almost immediately and therefore does not serve to provide long term scale protection.

Various techniques have been used successfully to increase the proportion of scale inhibitor retention in the well during squeeze treatments. For example, it has been reported previously in many papers where poly amino acids and poly quaternary amines have been injected into a well as part of the pre flush process and have significantly improved scale inhibitor retention and scale squeeze lifetimes. It has now been found that scale inhibitor treatment lifetimes can be improved by incorporating an ionic polymer such as a poly amino acid or poly quaternary amine in the over flush stage of the squeeze treatment. Indeed this method has been found to further extend the treatment lifetimes when combined with the same additives in the pre-flush stage of the scale squeeze treatment.

The new scale squeeze design technology can be considered very flexible as it can be applied with most scale inhibitor chemistries including both phosphonates and polymers with minimal formation damage potential compared to most precipitation scale squeeze treatments. It should be applicable over a wide temperature range from 30°C to 200°C and, in addition, the treatment strategy also lends itself to both aqueous and non-aqueous deployment and hybrid treatments and could provide extra protection against fines production in water sensitive wells depending upon the ionic polymer deployed. Initial field treatments have demonstrated the potential to extend treatment lifetimes by retaining up to 20 to 50% more useful chemical in the treatment reservoir.

This paper will highlight the proposed mechanisms of how the ionic polymer additives can improve squeeze treatment lifetimes as part of the over flush and will present field data for treatments on two wells in an HP/HT field at 165°C that demonstrated improved chemical retention and scale inhibitor returns compared to treatments without the ionic polymer additive in the over flush.
Automatic Isotherm Derivation from Field Data for Oilfield Scale Inhibitor Squeeze Treatments
Authors: Vazquez O. , Corne D. , Jordan M. M. , Mackay E. J.
Published: May 2012

Oilfield scale formation represents a very significant flow assurance challenge to the oil and gas industry, with increasing water production worldwide and higher oil prices. Scale Inhibitor (SI) squeeze treatment is the most widespread method to combat downhole scaling. In order to predict SI squeeze treatments accurately for further optimisation, it is necessary to simulate the SI retention in the formation, which may be described by pseudo-adsorption isotherms. While these are often derived from core flood experiments, sometimes they are not appropriate for modelling well treatments because the core tests on which they are based cannot fully represent field scale processes. In practice, the parameters of an analytic form of the isotherm equation are modified by trial and error by an experienced practitioner until a match is obtained between the prediction and the return profile of the first treatment in the field.

The main purpose of this paper is to present a Stochastic Hill Climbing Algorithm for automatic isotherm derivation. The performance of the algorithm was evaluated using data from three field cases. Two success criteria were defined: firstly, ability to match a single historical treatment and secondly, ability to predict subsequent successive treatments. To test for the second criterion, a candidate isotherm was derived from the first treatment in a well that was treated with the same chemical package on consecutive occasions, and then the predictions using the suggested solution were compared with the observed scale inhibitor concentration return profiles from the subsequent treatments. In all the calculations, performance of the isotherms suggested by the Hill Climbing algorithm and isotherms derived by trial and error were compared. The results demonstrate that the Hill Climber Algorithm is a very effective technique for deriving an isotherm to enable accurate modelling of scale inhibitor squeeze treatments.
The Effect of pH on Static Barium Sulphate Inhibition Efficiency and Minimum Inhibitor Concentration of Generic Scale Inhibitors
Authors: Shaw S. S. , Sorbie K. S.
Published: May 2012

This paper discusses the effect of pH on the static barium sulphate inhibition efficiency (IE) of four scale inhibitors: DETPMP and HMTPMP (both penta-phosphonates), EDTMPA (a tetra-phosphonate), and PPCA (a phosphino poly carboxylate). pH is an important parameter with regard to SI functionality. The effect of pH on each SIs IE is explained in terms of SI speciation and binding to Ca2+ and Mg2+ (and possibly Ba2+, Sr2+). In some cases there is an "optimum pH" for the effective operation of a specific SI, depending on the nature of the functional groups present in the chemical structure.

All static IE experiments were carried out at 95°C and using a North Sea Seawater/Formation Water (NSSW/FW) mixing ratio = 80/20. pH levels of 4.5, 5.5, 6.5 and 7.5 were chosen for testing since this covers the entire range which threshold level SI concentration might normally experience in a reservoir. The IE was determined for each SI at each pH level, where the [SI] was chosen close to the threshold MIC (i.e. pre-2 hour MIC) such that the specific effects of varying pH on 2 and 22 hour IE were clearly visible. In some tests MIC levels were reached, and in these cases, findings are presented in terms of MIC versus pH. For all four species tested, IE versus pH charts are presented. Furthermore, two brine mix compositions (maintaining NSSW/FW = 80/20) were examined, one with [Ca2+] = 742ppm and [Mg2+] = 1242ppm (base case) and one with [Ca2+] = 2000ppm and [Mg2+] = 739ppm (fixed case). The base case [Ca2+] and [Mg2+] result from the normal mixing of NSSW and FW in an 80/20 ratio, molar ratio Ca2+/Mg2+ = 0.36. In the fixed case mix, molar ratio Ca2+/Mg2+ = 1.64. This is done in order to compare and context results within an extensive earlier series of IE results for SIs which were tested in this manner (Shaw et al, 2010a, 2010b).
A Simple Model of Precipitation Squeeze Treatments
Authors: Sorbie K. S.
Published: May 2012

Scale inhibitors are retained within porous media by the two main mechanisms of "adsorption" (Γ) and "precipitation" (Π). In previous experimental and modelling work, we have demonstrated for static (equilibrium) "apparent adsorption" tests where the system exhibits either (a) adsorption only or (b) it is in the coupled adsorption/precipitation (Γ/Π) regime. A complete model of SI retention must have (i) an equilibrium description of the coupled Γ/Π process (Kahrwad et al, 2008); (ii) a kinetic model of coupled Γ/Π which correctly limits to the equilibrium case (i.e. the kinetics must be consistent with the equilibrium Γ/Π model as t → ∞); (iii) the full kinetic Γ/Π model must then be embedded in a transport model for flow through porous media. Some progress towards this full model has been made and reported previously (Sorbie, 2010; Vazquez et al, 2010).

The full coupled kinetic Γ/Π model is comprehensive and is currently being verified by experiment. However, this full model is quite complex and difficult to understand. Therefore, in this paper, we present a new simple model of kinetic precipitation (Π) which explains some key features of this process. This work will present 3 key new findings, as follows: (i)a very simple mathematical explanation of the mechanism and observations in kinetic precipitation;(ii)some simple but novel analytical formulae which describe the process;(iii)a worked field scale radial kinetic precipitation examples is presented which demonstrates how to estimate whether a given field system is close to or far from precipitation/dissolution equilibrium.

This simpler model represents an end-member where a precipitating SI system is described by a solubility (Cs) and a dissolution rate, k. In most practical cases, some level of adsorption is also superimposed upon this behaviour but this is neglected in this simple model. However, understanding the behaviour of this idealized system does give us some mechanistic insights and some simple practical formula for precipitation squeeze design purposes.
Modelling of Enhanced Scale Control via Inhibition of Stimulation Fluids for Deepwater Developments
Authors: Ishkov Oleg , Mackay Eric , Jordan Myles
Published: May 2012

The injection of seawater into oil bearing reservoirs to maintain reservoir pressure and improve secondary recovery is a well-established, mature operation. Moreover, the degree of risk posed by deposition of mineral scales (carbonate/sulphate) to the injection and production wells during such operations has been much studied. The current deepwater subsea developments offshore West Africa, Gulf of Mexico and Brazil have brought into sharp focus the need to manage scale in an effective way.

In recent years there has been some consideration given to deployment of scale inhibitor within the fluids associated with the completion of production wells, prior to the start up of production. Until now, effective scale control in frac packed wells at low water cuts has been achieved with phosphonate-based inhibitors applied as part of the acid perforation wash and overflush stages, prior to the actual frac packing operation itself. The deployment of these inhibitors has proved effective in controlling barium sulphate scale formation during initial seawater production, and eliminating the need to scale squeeze the wells at low water cuts (<10% BS&W). Recent developments allowing inclusion of scale inhibitor in the linear and cross linked gel stages has highlighted the need to be able to model this process effectively, thereby enabling optimal use of the chemical and improved squeeze designs.

This paper outlines simulation work carried out using the Petroleum Experts REVEAL software to assess introduction of scale inhibitor into frac pack operations, and identify the most suitable stage of the well completion process during which to apply the inhibitor, to maximise treatment life. Simulation results and field data from these treatments are compared to demonstrate the opportunity this technique presents, and to highlight the importance of chemical placement and the post stimulation flow regime to squeeze life.