A Longitudinal Investigation of Infant Gesture Use and Parent Speech: Unique and Dynamic Influences on Infant Vocabulary Acquisition

How do infants learn word meanings? Research has established the impact of both parent and child behaviors on vocabulary development, however the processes and mechanisms underlying these relationships are still not fully understood. Much existing literature focuses on direct paths to word learning, demonstrating that parent speech and child gesture use are powerful predictors of later vocabulary. However, an additional body of research indicates that these relationships don’t always replicate, particularly when assessed in different populations, contexts, or developmental periods.

The current study examines the relationships between infant gesture, parent speech, and infant vocabulary over the course of the second year (10-22 months of age). Through the use of detailed coding of dyadic mother-child play interactions and a combination of quantitative and qualitative data analytic methods, the process of communicative development was explored. Findings reveal non-linear patterns of growth in both parent speech content and child gesture use. Analyses of contingency in dyadic interactions reveal that children are active contributors to communicative engagement through their use of gestures, shaping the type of input they receive from parents, which in turn influences child vocabulary acquisition. Recommendations for future studies and the use of nuanced methodologies to assess changes in the dynamic system of dyadic communication are discussed.

Advanced Placement and American Education: A Foucauldian Analysis of the Advanced Placement Program of the College Board

Advanced Placement is a series of courses and tests designed to determine mastery over introductory college material. It has become part of the American educational system. The changing conception of AP was examined using critical theory to determine what led to a view of continual success. The study utilized David Armstrong’s variation of Michel Foucault’s critical theory to construct an analytical framework. Black and Ubbes’ data gathering techniques and Braun and Clark’s data analysis were utilized as the analytical framework. Data included 1135 documents: 641 journal articles, 421 newspaper articles and 82 government documents. The study revealed three historical ruptures correlated to three themes containing subthemes. The first rupture was the Sputnik launch in 1958. Its correlated theme was AP leading to school reform with subthemes of AP as reform for able students and AP’s gaining of acceptance from secondary schools and higher education. The second rupture was the Nation at Risk report published in 1983. Its correlated theme was AP’s shift in emphasis from the exam to the course with the subthemes of AP as a course, a shift in AP’s target population, using AP courses to promote equity, and AP courses modifying curricula. The passage of the No Child Left Behind Act of 2001 was the third rupture. Its correlated theme was AP as a means to narrow the achievement gap with the subthemes of AP as a college preparatory program and the shifting of AP to an open access program. The themes revealed a perception that progressively integrated the program into American education. The AP program changed emphasis from tests to curriculum, and is seen as the nation’s premier academic program to promote reform and prepare students for college. It has become a major source of income for the College Board. In effect, AP has become an agent of privatization, spurring other private entities into competition for government funding. The change and growth of the program over the past 57 years resulted in a deep integration into American education. As such the program remains an intrinsic part of the system and continues to evolve within American education.

Responsibility and Well-Being: Resource Integration Under Responsibilization in Expert Services

Responsibilization, or the shift of functions and risks from providers and producers to consumers, has become an increasingly common policy in service systems and marketplaces (e.g., financial, health, governmental). As responsibilization is often considered synonymous with consumer agency and well-being, the authors take a transformative service research perspective and draw on resource integration literature to investigate whether responsibilization is truly associated with well-being. The authors focus on expert services, for which responsibilization concerns are particularly salient, and question whether this expanding policy is in the public interest. In the process, they develop a conceptualization of resource integration under responsibilization that includes three levels of actors (consumer, provider, and service system), the identification of structural tensions to resource integration, and three categories of resource integration practices (access, appropriation, and management) necessary to negotiate responsibilization. The findings have important implications for health care providers, public and institutional policy makers, and other service systems, all of which must pay more active attention to the challenges consumers face in negotiating responsibilization and the resulting well-being outcomes.

Responsibility and Well-being: Resource Integration under Responsibilization in Expert Services

Responsibilization, or the shift in functions and risks from providers and producers to the consumer, has become an increasingly common policy in service systems and marketplaces (e.g., financial, health, governmental). Responsibilization is often presented as synonymous with consumer agency and well-being. We take a transformative service research perspective and utilize the resource integration framework to investigate whether responsibilization is truly associated with well-being. We focus on expert services, where responsibilization concerns are particularly salient, and question whether this expanding policy is in the public interest. In the process, we develop a conceptualization of resource integration under responsibilization that includes three levels of actors (consumer, provider and service system), the identification of structural tensions to resource integration and three categories of resource integration practices (access, appropriation and management) necessary to negotiate responsibilization. Our findings have important implications for health care providers, public policy makers, and other service systems, all of which must pay more active attention to the challenges consumers face in negotiating responsibilization and the resulting well-being outcomes.

Evaluation of creative problem solving abilities in undergraduate structural engineers through interdisciplinary problem based learning

For a structural engineer, effective communication and interaction with architects cannot be underestimated as a key skill to success throughout their professional career. Structural engineers and architects have to share a common language and understanding of each other in order to achieve the most desirable architectural and structural designs. This interaction and engagement develops during their professional career but needs to be nurtured during their undergraduate studies. The objective of this paper is to present the strategies employed to engage higher order thinking in structural engineering students in order to help them solve complex problem-based learning (PBL) design scenarios presented by architecture students. The strategies employed were applied in the experimental setting of an undergraduate module in structural engineering at Queen’s University Belfast in the UK. The strategies employed were active learning to engage with content knowledge, the use of physical conceptual structural models to reinforce key concepts and finally, reinforcing the need for hand sketching of ideas to promote higher order problem-solving. The strategies employed were evaluated through student survey, student feedback and module facilitator (this author) reflection. The strategies were qualitatively perceived by the tutor and quantitatively evaluated by students in a cross-sectional study to help interaction with the architecture students, aid interdisciplinary learning and help students creatively solve problems (through higher order thinking). The students clearly enjoyed this module and in particular interacting with structural engineering tutors and students from another discipline

Fabrication, Optical Analysis and Photonic Applications of Certain Metallic Nanostructure-Integrated Dye Doped Polymer Optical Fibers” submitted by Ms. Suneetha Sebastian

Polymer Optical Fibers have occupied historically a place for large core flexible fibers operating in short distances. In addition to their practical passive application in short-haul communication they constitute a potential research field as active devices with organic dopants. Organic dyes are preferred as dopants over organic semiconductors due to their higher optical cross section. Thus organic dyes as gain media in a polymer fiber is used to develop efficient and narrow laser sources with a tunability throughout the visible region or optical amplifier with high gain. Dyes incorporated in fiber form has added advantage over other solid state forms such as films since the pump power required to excite the molecules in the core of the fiber is less thereby utilising the pump power effectively. In 1987, Muto et.al investigated a dye doped step index polymer fiber laser. Afterwards, numerous researches have been carried out in this area demonstrating laser emission from step index, graded index and hollow optical fibers incorporating various dyes. Among various dyes, Rhodamine6G is the most widely and commonly used laser dye for the last four decades. Rhodamine6G has many desirable optical properties which make it preferable over other organic dyes such as Coumarin, Nile Blue, Curcumin etc. The research focus on the implementation of efficient fiber lasers and amplifiers for short fiber distances. Developing efficient plastic lasers with electrical pumping can be a new proposal in this field which demands lowest possible threshold pump energy of the gain medium in the cavity as an important parameter. One way of improving the efficiency of the lasers, through low threshold pump energy, is by modifying the gain of the amplifiers in the resonator/cavity. Success in the field of Radiative Decay Engineering can pave way to this problem. Laser gain media consisting of dye-nanoparticle composites can improve the efficiency by lowering the lasing threshold and enhancing the photostability. The electric field confined near the surface of metal nanoparticles due to Localized Surface Plasmon Resonance can be very effective for the excitation of active centers to impart high optical gain for lasing. Since the Surface Plasmon Resonance of nanoparticles of gold and silver lies in the visible range, it can affect the spectral emission characteristics of organic dyes such as Rhodamine6G through plasmon field generated by the particles. The change in emission of the dye placed near metal nanoparticles depend on plasmon field strength which in turn depends on the type of metal, size of nanoparticle, surface modification of the particle and the wavelength of incident light. Progress in fabrication of different types of nanostructures lead to the advent of nanospheres, nanoalloys, core-shell and nanowires to name a few. The thesis deals with the fabrication and characterisation of polymer optical fibers with various metallic and bimetallic nanostructures incorporated in the gain media for efficient fiber lasers with low threshold and improved photostability.

Relação Entre Motivação e Desempenho Escolar em Alunos do 1º Ciclo

O presente estudo teve como objectivo analisar a existência de uma possível relação entre motivação (intrínseca ou extrínseca) e o desempenho escolar em alunos do 1º ciclo que frequentam o 4º ano. A amostra foi constituída por 62 alunos, com idades compreendidas entre os 9 e 10 anos, 15 que frequentavam a Escola Básica do 1º Ciclo de Brancas e 47 a Escola Básica da Batalha (24 alunos da Turma A e 23 da Turma B). Considerando a possível existência de variáveis sociodemográficas associadas ao desempenho, no processo de recolha de dados foi aplicado um questionário sóciodemográfico, que pela sua potencial natureza descritiva, interpretativa e reflexiva, constituiu uma importante ferramenta na análise e avaliação dos resultados obtidos. Com o objectivo de avaliar a motivação (intrínseca e extrínseca) foi administrada uma escala de motivação escolar, aferida para a população portuguesa contendo 18 questões. Cada uma destas questões contém 4 possibilidades de resposta (duas referentes à motivação intrínseca e outras duas referentes à motivação extrínseca). Quanto ao desempenho escolar, este foi avaliado através das notas que os alunos obtiveram no final do ano lectivo e que foram facultadas pelas professoras dos mesmos. A análise dos resultados evidenciou que existe uma relação entre a motivação e o desempenho escolar, concluindo-se que os alunos intrinsecamente motivados apresentam melhor desempenho do que os alunos extrinsecamente motivados. Consideramos deste modo, que a implementação de estratégias na sala de aula que promovam a motivação intrÍnseca será mais benéfico para o sucesso escolar dos alunos. / The objective of this study, is to analyze the possible relation between intrinsic and extrinsic motivation and the educational achievement in students in the fourth grade of grade school. The sample was composed by 62 students, with a ages between 9 and 10 years of age. 15 students of this sample attended the grade school of Brancas, 47 attended the grade school of Batalha ( 24 of the students are from class A and 23 are from class B). Considering a possible existence of sociodemographic variables related to achievement, in the process of data collecting, a sociodemographic questionnaire was used, considering its great potential to describe, interpret analyze and evaluate the results obtained. To evaluate intrinsic and extrinsic motivation, a scale of school motivation adapted for Portuguese population with eighteen questions was applied. Each of these questions has 4 possibilities of response (two referring to intrinsic motivation and two referring to extrinsic motivation). In what concerns to school achievement, this was evaluated trough school grades obtained at the end of the school year given by the teachers. The analyses of the results demonstrated that there are differences between motivation and school achievement, concluding that the students with intrinsic motivation present better achievement then the students with extrinsic motivation. The implementation of strategies in the classroom, will promote intrinsic motivation and bring more success to students.

Envolvimento Parental e Nível Sociocultural das Famílias

O envolvimento parental refere-se a todas as actividades realizadas pelos pais na educação dos filhos. Os pais desempenham um papel fundamental no processo de escolaridade dos filhos. Um dos aspectos que mais influencia a qualidade do envolvimento parental na escolarização dos filhos é o nível sociocultural dos pais. Entende-se por nível sociocultural todo o tipo de experiências sociais e culturais que a criança tem acesso na família. O objectivo principal deste estudo é avaliar a relação entre o nível sociocultural das famílias e o envolvimento parental na escolaridade dos filhos. São objectivos complementares desta investigação, verificar quais os factores socioculturais que estão mais significativamente associados ao envolvimento parental na escolarização dos filhos e quais as dimensões comportamentais deste envolvimento que mais contribuem para adaptação escolar dos filhos. Para concretizar estes objectivos, foi realizado um estudo epidemiológico descritivo, em corte transversal, a fim de avaliar uma amostra de 92 pais de alunos do 1º Ciclo do ensino básico pertencentes ao agrupamento de escolas do concelho de Coimbra. O protocolo de investigação é constituído pelo questionário de envolvimento parental na escola, versão para pais (QEPE, Pereira, 2002), e a escala de Graffar adaptada à população portuguesa, para avaliar o nível sociocultural das famílias dos alunos. Os resultados obtidos revelam que as famílias com um nível sociocultural mais elevado apresentam um maior envolvimento na escolaridade dos filhos. Verificamos que os factores socioculturais mais significativamente associados à qualidade do envolvimento dos pais são a profissão e o nível de instrução do chefe de família. Verificámos, ainda, que as dimensões comportamentais mais privilegiadas pelos pais na escolaridade dos filhos são as actividades de aprendizagem em casa, comunicação escola-família e actividades na escola e reuniões de pais. Concluímos que o nível sociocultural influencia a qualidade do envolvimento parental. O nível de escolaridade e a profissão dos pais são factores determinantes para a qualidade desse envolvimento. /

Intervenção Social - Arte ou Ciência?: O Assistente Social como agente de mudança numa autarquia de interior.

O presente trabalho baseia-se na pesquisa documental e na análise crítico-reflexiva sobre o serviço social no Poder Local, a sua evolução, influências e implicações no trabalho desenvolvido no (pelo) Gabinete de Ação Social do Município de Pampilhosa da Serra. O serviço social assume, durante o Estado Novo, um papel de controle, com uma prática associada essencialmente ao Estado e a algumas entidades da sociedade civil, nomeadamente à Igreja Católica. Com a Era Democrática, assiste-se ao crescimento da intervenção do Estado e à descentralização da sua atuação para as Autarquias, assumindo-se o SAAL (1974) como um marco histórico. A intervenção ganha, assim, um caráter “territorial” crescendo as responsabilidades das autarquias, quer no âmbito das transferências de competências por parte do Poder Central, quer ao nível da dinamização de serviços de âmbito municipal e da criação de respostas sociais específicas. O PRS (1997) e a RLIS (2013), apresentam-se como exemplos dessa territorialização, reforçando as atribuições das Autarquias ao nível da ação social. O primeiro, implementado a nível nacional, visa a articulação de recursos e uma intervenção integrada. Tem como princípios, a promoção a participação da população e dos agentes locais quer na elaboração de diagnósticos sociais, quer na criação de respostas adequadas às necessidades. A segunda, em fase de implementação, visa a criação de uma metodologia de trabalho ao nível do atendimento e acompanhamento social. Destaca-se o papel das Autarquias e da Sociedade Civil, na efetivação de uma intervenção social de proximidade. A crescente desresponsabilização do Estado na intervenção social, em particular do Poder Central, motivada pela Crise Económica, provoca alterações nas políticas sociais. Surgem as políticas de inserção direcionadas para públicos específicos, tendencialmente contratualizadas e centradas no sujeito. Estas alterações tiveram, também, implicações na atuação do Município de Pampilhosa da Serra, onde o serviço social se desenvolveu a par da implementação dos programas de âmbito comunitário, nomeadamente do PDIAS e PLCP (1996) e do projecto-piloto do RMG (1997). Sistematizou-se com a implementação das Redes Sociais e operacionaliza-se no Gabinete de Ação Social, atuando em três dimensões: mediação, promoção e execução. Da análise e reflexão em torno da atuação do GAS, no qual inscrevemos a nossa intervenção profissional, consideramos que esta se desenvolve numa relação sociopolítica e operacional, assumindo a Autarquia um papel ativo ao criar e/ou reforçar medidas de apoio socioeducativo e económico, de forma a garantir o bem-estar social e a qualidade de vida dos cidadãos Pampilhosenses. O município assume-se como o patamar de atuação de proximidade por excelência, onde o local se perspetiva como o espaço onde a intervenção social se operacionaliza, enquanto que o Poder Local, em conjunto com a sociedade Civil, assumem o poder de co construir a mudança social. / This work is based on documentary research and critical and reflective analysis of the social service in Local Government, its evolution, influences and implications on the work of the (at) Social Action Office of the municipality of Pampilhosa da Serra. The social service assumes, during the Estado Novo, a paper control, primarily associated with a practice the state and some civil society organizations, including the Catholic Church. With the Democratic Era, we are witnessing the growth of state intervention and the decentralization of its activities to the local authorities, assuming the SAAL (1974) as a historical landmark. Intervention win, so a character "territorial" growing responsibilities of local authorities, or within the transfer of responsibilities from the Central Power, both in terms of promotion of municipal services and the creation of specific social responses. The PRS (1997) and the RLIS (2013), are presented as examples of territorial, strengthening the powers of local authorities to the level of social action. The first, implemented nationally, aimed at articulating features and an integrated intervention. Its principles, promoting the participation of the population and local actors when developing social diagnosis, whether the creation of appropriate responses to the needs. The second, under implementation, aims to create a working methodology in terms of care and social support. It highlights the role of local authorities and civil society in the execution of a social intervention proximity. The growing irresponsibility of the state in social intervention, in particular the Central Power, motivated by the economic crisis, causes changes in social policies. Arise inclusion policies targeting specific audiences tend contracted and centered on the subject. These changes have also implications for the work of the municipality of Pampilhosa da Serra, where the social work developed together with the implementation of Community-wide programs, including the PDIAS and PLCP (1996) and the pilot project of RMG (1997). Systematized with the implementation of Social Networks and made operational in the Social Action Office, working in three dimensions: mediation, promotion and implementation. Analysis and reflection around the GAS operation, in which we inscribe our professional intervention, we believe that this is developed in a socio-political and operational relationship, assuming the Municipality an active role to create and / or strengthen measures of socio-educational and economic support, to ensure the welfare and quality of life of citizens Pampilhosenses. The municipality is assumed as the proximity actuation level par excellence where the location is perspective as the space where social intervention made operational, while the Local Government, together with civil society, assume the co power build social change.

Elettrodeposizione di catalizzatori a base di Rh su schiume e fibre metalliche di FeCrAlloy per la produzione di syngas

The preparation of structured catalysts active in the catalytic partial oxidation of methane to syngas, was performed by electrosynthesis of hydroxides on FeCrAlloy foams and fibers. Rh/Mg/Al hydrotalcite-type compounds were prepared by co-precipitation of metallic cations on the support and successive calcination. Electrochemical reactions have been studied during the electrodeposition by linear sweep voltammetry. The experiments were performed at supports immersed in KNO3, KCl, Mg2+ and Al3+ aqueous solutions, starting by different precursors (nitrate and chlorides salts) and modifying the Mg/A ratio. Rh/Mg/Al hydrotalcite-type compounds were deposited on metal foams by applying a -1.2V vs SCE potential for 2000s with a nitrate solution of 0.06M total metal concentration. Firstly it was studied the effect of Mg on the coating propierties, modifying the Rh/Mg/Al atomic ratio (5/70/25, 5/50/45, 5/25/70 e 5/0/95). Then the effect of the amount of Rh was later investigated in the sample with the largest Mg content (Rh/Mg/Al = 5/70/25 and 2/70/28).The results showed that magnesium allowed obtaining the most homogeneous and well adherent coatings, wherein rhodium was well dispersed. The sample with the Rh/Mg /Al ratio equal to5/70/25 showed the best catalytic performances. Decreasing the Rh content, the properties of the coating were not modified, but the catalytic activity was lower, due to a not enough number of active sites to convert the methane. The work on metal fibers focused on the effect of precursor concentration, keeping constant composition, potential and synthesis time at the values of Rh/Mg/Al =5/70/25, -1.2V vs SCE and 1000s. However fibers geometry did not allow to obtain a high quality coating, even if results were quite promising.

The Importance of Learning History and Philosophy of Computing

Computers have invaded our offices, our homes, cars and coffee-pots; they have become ubiquitous. However, the advance of computing technologies is associated with an increasing lack of “visibility” of the underlying software and hardware technologies. While we use and accept the computer, we neither know its history nor functionality. In this paper, we argue that this is not a healthy situation. Also, recruitment onto UK Computing degree courses is steadily falling; these courses are appearing less attractive to school-leavers. This may be associated with the increasing ubiquity. In this paper we reflect on an MSc. module of instruction, Concepts and Philosophy of Computing, and a BSc. module Computer Games Development developed at the University of Worcester which address these issues. We propose that the elements of these modules form a necessary part of the education of all citizens, and we suggest how this may be realized. We also suggest how to re-enthuse our youth about computing as a discipline and halt the drop in recruitment.

The Importance of Learning History and Philosophy of Computing

Computers have invaded our offices, our homes, cars and coffee-pots; they have become ubiquitous. However, the advance of computing technologies is associated with an increasing lack of “visibility” of the underlying software and hardware technologies. While we use and accept the computer, we neither know its history nor functionality. In this paper, we argue that this is not a healthy situation. Also, recruitment onto UK Computing degree courses is steadily falling; these courses are appearing less attractive to school-leavers. This may be associated with the increasing ubiquity. In this paper we reflect on an MSc. module of instruction, Concepts and Philosophy of Computing, and a BSc. module Computer Games Development developed at the University of Worcester which address these issues. We propose that the elements of these modules form a necessary part of the education of all citizens, and we suggest how this may be realized. We also suggest how to re-enthuse our youth about computing as a discipline and halt the drop in recruitment.

La victimisation par les pairs et le fait d'apporter des objets pouvant servir d'arme à l'école

Les élèves vivant dans la crainte d’être victimisés par leurs pairs peuvent se comporter de différentes façons, notamment en évitant de se rendre à l’école ou encore en imaginant différents moyens d’autoprotection (ex., apporter divers objets potentiellement dangereux à l’école). L’objectif de ce mémoire est de vérifier s’il existe des liens entre la victimisation par les pairs et le fait d’apporter des objets potentiellement dangereux et pouvant servir d’arme à l’école. L’échantillon est composé de 28 015 élèves de la première à la cinquième secondaire (12 à 17 ans) en provenance des écoles secondaires publiques du Québec. Les participants ont rempli le Questionnaire sur la Sécurité et la Violence à l’école Révisé (QSVE-R) visant à dresser le portrait de la violence dans les établissements scolaires du Québec. Les résultats démontrent que 5,1 % des élèves, davantage de garçons (8,2 %) que de filles (2,1 %) disent avoir déjà apporté un objet potentiellement dangereux à l’école. Le risque d’apporter ces objets augmente avec l’âge et c’est le couteau qui est l’objet le plus populaire auprès des répondants. L’étude confirme l’influence de la victimisation de type direct (insultes-menaces et agressions physiques), du sexe (garçons) et de l’âge (17 ans et plus) sur le fait d’apporter un objet pouvant servir d’arme à l’école. En plus de proposer des pistes d’études futures pour en connaître davantage sur ce que vivent les élèves victimisés à l’école, les conclusions de cette recherche soulèvent l’importance d’aider ces jeunes victimes à développer de meilleures stratégies afin de mieux gérer cette situation pénible, et amènent des réflexions pour orienter les interventions visant à créer des milieux scolaires sécurisants pour tous.

Séquestration géologique du CO2 par carbonatation minérale dans les résidus miniers

La carbonatation minérale dans les résidus miniers est un moyen sûr et permanent de séquestrer le CO2 atmosphérique. C’est un processus naturel et passif qui ne nécessite aucun traitement particulier et donc avantageux d’un point de vue économique. Bien que la quantité de CO2 qu’il soit possible de séquestrer selon ce processus est faible à l’échelle globale, dans le cadre d’un marché du carbone, les entreprises minières pourraient obtenir des crédits et ainsi revaloriser leurs résidus. À l’heure actuelle, il y a peu d’informations pour quantifier le potentiel de séquestration du CO2 de façon naturelle et passive dans les piles de résidus miniers. Il est donc nécessaire d’étudier le phénomène pour comprendre comment évolue la réaction à travers le temps et estimer la quantité de CO2 qui peut être séquestrée naturellement dans les piles de résidus. Plusieurs travaux de recherche se sont intéressés aux résidus miniers de Thetford Mines (Québec, Canada), avec une approche principalement expérimentale en laboratoire. Ces travaux ont permis d’améliorer la compréhension du processus de carbonatation, mais ils nécessitent une validation à plus grande échelle sous des conditions atmosphériques réelles. L’objectif général de cette étude est de quantifier le processus de carbonatation minérale des résidus miniers sous des conditions naturelles, afin d’estimer la quantité de CO2 pouvant être piégée par ce processus. La méthodologie utilisée repose sur la construction de deux parcelles expérimentales de résidus miniers situées dans l’enceinte de la mine Black Lake (Thetford Mines). Les résidus miniers sont principalement constitués de grains et de fibres de chrysotile et lizardite mal triés, avec de petites quantités d’antigorite, de brucite et de magnétite. Des observations spatiales et temporelles ont été effectuées dans les parcelles concernant la composition et la pression des gaz, la température des résidus, la teneur en eau volumique, la composition minérale des résidus ainsi que la chimie de l’eau des précipitations et des lixiviats provenant des parcelles. Ces travaux ont permis d’observer un appauvrissement notable du CO2 dans les gaz des parcelles (< 50 ppm) ainsi que la précipitation d’hydromagnésite dans les résidus, ce qui suggère que la carbonatation minérale naturelle et passive est un processus potentiellement important dans les résidus miniers. Après 4 ans d’observations, le taux de séquestration du CO2 dans les parcelles expérimentales a été estimé entre 3,5 et 4 kg/m3/an. Ces observations ont permis de développer un modèle conceptuel de la carbonatation minérale naturelle et passive dans les parcelles expérimentales. Dans ce modèle conceptuel, le CO2 atmosphérique (~ 400 ppm) se dissout dans l’eau hygroscopique contenue dans les parcelles, où l’altération des silicates de magnésium forme des carbonates de magnésium. La saturation en eau dans les cellules est relativement stable dans le temps et varie entre 0,4 et 0,65, ce qui est plus élevé que les valeurs de saturation optimales proposées dans la littérature, réduisant ainsi le transport de CO2 dans la zone non saturée. Les concentrations de CO2 en phase gazeuse, ainsi que des mesures de la vitesse d’écoulement du gaz dans les cellules suggèrent que la réaction est plus active près de la surface et que la diffusion du CO2 est le mécanisme de transport dominant dans les résidus. Un modèle numérique a été utilisé pour simuler ces processus couplés et valider le modèle conceptuel avec les observations de terrain. Le modèle de transport réactif multiphase et multicomposant MIN3P a été utilisé pour réaliser des simulations en 1D qui comprennent l’infiltration d’eau à travers le milieu partiellement saturé, la diffusion du gaz, et le transport de masse réactif par advection et dispersion. Même si les écoulements et le contenu du lixivat simulés sont assez proches des observations de terrain, le taux de séquestration simulé est 22 fois plus faible que celui mesuré. Dans les simulations, les carbonates précipitent principalement dans la partie supérieure de la parcelle, près de la surface, alors qu’ils ont été observés dans toute la parcelle. Cette différence importante pourrait être expliquée par un apport insuffisant de CO2 dans la parcelle, qui serait le facteur limitant la carbonatation. En effet, l’advection des gaz n’a pas été considérée dans les simulations et seule la diffusion moléculaire a été simulée. En effet, la mobilité des gaz engendrée par les fluctuations de pression barométrique et l’infiltration de l’eau, ainsi que l’effet du vent doivent jouer un rôle conséquent pour alimenter les parcelles en CO2.

Disortografia

É significativo o número de alunos brasileiros que apresentam, em maior ou menor grau, problemas relacionados com a escrita, independentemente do seu ano de escolaridade ou formação. Dentro das salas de aulas essa é uma realidade que todos nós conhecemos. E por conhecer essa realidade é que reconhecemos que isto influencia de uma forma negativa a formação de nossos estudantes. Na verdade, se estas dificuldades não forem detetadas atempadamente, os custos serão enormes, quer em termos pessoais quer em termos sociais, já que essas dificuldades tendem a se manter na vida adulta. O papel do professor assume-se, deste modo, fundamental na identificação precoce destes casos e na adequação do processo de ensino-aprendizagem na senda do sucesso escolar. No entanto, não raras vezes o seu trabalho é dificultado ou pelo desconhecimento da problemática em questão ou pela falta de uma política educativa que, a nível dos gestores escolares, permita potenciar a sua atividade de docente. É neste contexto que surge o presente trabalho que tem por objetivo analisar as conceções e as práticas pedagógicas na área da disortografia. Para tanto, abordaremos o conceito de disortografia e suas implicações na leitura e escrita, com ênfase no último aspecto, já que a dificuldade se dá justamente na grafia. No sentido de melhor compreender a realidade de algumas escolas do ensino fundamental e médio do Brasil, foi conduzido um estudo exploratório, com recurso à técnica do questionário, tendo sido inquiridos 31 professores e 11 gestores de escolas públicas e privadas. Os resultados evidenciaram, entre outros aspetos, algum desconhecimento sobre disortografia bem como algumas divergências entre estes dois agentes educativos quanto às características desta perturbação e quanto às melhores estratégias e medidas educativas para crianças com este diagnóstico. Com base nestes resultados é proposto um esboço de um programa de intervenção junto da comunidade educativa.