71 research outputs found

    The Longitudinal Flow of Oil and Petroleum Products in the Channels and Pipes. Part II

    Get PDF
    A model associated fluid flow and heat transfer of longitudinal flows of oil in pipes and channels is considered. The model is an extended version of the Bingham flow on the case of flow with one or two solid cores. The fluid part is a two-phase medium, wherein the disperse phase may consist of solid particles, droplets and gas bubbles. The sliding on the borders of pipes and channels, thermal conductivity and viscosity of such systems and their impact on the characteristics of the solid core are discussed. The flow with a yield point dependence on the temperature is also considered

    Print awareness of adult illiterates: a comparison with young pre-readers and low-educated adult readers

    Get PDF
    In this study the print awareness of 25 unschooled adult illiterates in the Netherlands was compared with that of 24 pre-reading children and of 23 low-educated literate adults with approximately four years of primary schooling. The illiterates were interviewed about their experiences with writing and all participants completed six assessments of print awareness in the language they preferred (first or second language). The outcomes revealed that the three groups did not differ in distinguishing conventional written signs from other visual signs, that both groups of non-readers differed significantly from low educated readers but not from each other in knowledge of logos, inscriptions and knowledge of the written register, while the adult illiterates performed significantly better than the children on grapheme knowledge. Adult illiterates in literate societies seem to be well informed about the uses and functions of written language and about what writing looks like, but like young children they are not good at reading environmental print out of context and in explaining what exactly is represented in writing. The variation in reactions within the group of illiterate adults could be related to existing models of emergent literacy. Implications for adult literacy education are discussed

    Reconhecimento antecipado de problemas ortográficos em escreventes novatos: quando e como acontecem

    Get PDF
    A aprendizagem da ortográfica constitui um processo complexo, envolvendo questões lexicais e gramaticais. Muitos estudos sobre essa aprendizagem tratam os problemas ortográficos de modo independente e separado da produção textual. Neste estudo defendemos a importância de se analisar a aprendizagem da ortografia a partir da perspectiva proposta pela Genética Textual, colocando em destaque a gênese do processo de escritura e criação textual. Apresentamos o Sistema Ramos, metodologia de investigação que registra o processo de escritura em tempo e espaço real da sala de aula. Esse Sistema oferece informações multimodais (fala, escrita, gestualidade) sobre o que alunos, em duplas, reconhecem como problemas ortográficos (PO) e os comentários espontâneos feitos quando estão escrevendo o texto. Este estudo analisa justamente o momento em que aconteceram esses reconhecimentos e os comentários de duas alunas no 2º ano de escolaridade, durante a produção de seis histórias inventadas. Mais do que uma análise quantitativa dos tipos de PO identificados no produto, apresentamos uma análise enunciativa e microgenética de reconhecimentos de PO e seus comentários, particularmente aqueles PO antecipados pelas escreventes. Os resultados indicam: i. Reconhecimentos ensejam comentários nem sempre relacionados ao PO identificado; ii. Reconhecimentos e comentários estão relacionados aos conteúdos ortográficos ensinados em sala de aula; iii. Alguns PO reconhecidos envolvem a articulação de diferentes níveis linguísticos. Esses aspectos podem contribuir para a compreensão da aprendizagem da ortografia em situações didáticas propiciadas pela escrita colaborativa a dois.The acquisition of spelling competence is a complex process, involving lexical and grammatical questions. Research, however, almost always places the spelling from an autonomous point of view and disconnected from the other components of writing. In this text, we present the relevance of the Ramos System that captures students in an ecological situation of text production in pairs, allowing access to the processes for solving orthographic problems. Collaborative writing also grants access to comments made by students during the process of textual linearization. Our study focuses on the recognition of spelling problems (SP) and the comments made regarding such problems by two 2nd grade students during the production of six invented stories. More than a quantitative analysis of the types of SP identified in the product, we were interested in making a qualitative and fine analysis of oral recognitions of SP, particularly those SP anticipated by the writers. Our results indicate that: i. Recognition motivates comments that are not always related to the identified SP; ii. Recognition and comments are related to the orthographic contents taught in the classroom; iii. Some of the recognized SP involve the articulation between different linguistic levels. These aspects can contribute for the comprehension of orthographic learning in didactic situations provided by collaborative writing.publishe

    Mathematical Model of the Carbon Monoxide Conversion in Porous Catalyst

    No full text
    This article discusses the mathematical model of heat-build-up and component change in the multi-component gaseous mixture. The components take part in chemical reaction on a catalyst’s solid surface. The mathematical model describes pre-oxidation reaction of carbon monoxide to carbon dioxide. Practical situation, accounted by the studied model is that CO afterburning to C0₂ takes place in automobile engine’s exhaust gases for atmospheric condition improvement
    corecore