Investigation of laser based processes to optimize eletrospun nanofiber nonwovens for tissue engineering

Polymers and especially polymeric nanofibers are widely investigated in tissue engineering. These materials can imitate the extracellular matrix. Therefore, they can be used as scaffolds for growing human cells. However, in many cases a surface treatment of the nanofiber nonwovens is useful to enhance the cell adhesion. The polar and dispersion components of surface free energy have to be adjusted to control the wettability. To optimize the cell colonization on electrospun nanofibers, polyamide (PA 6.6) and polylactide (PLA) fibers were processed with different types of pulsed UV laser radiation. For comparison polyimide (PI), PA and PLA bulk materials were also investigated. Static contact angles were measured before and after laser processing to investigate the effects of laser irradiation on the wettability. The morphology of the treated areas was evaluated by confocal and scanning electron microscopy. Chemical analyses, like FTIR-ATR were also performed. The wettability of the different materials was changed. PA nanofiber nonwovens are hydrophilic and are appropriate for good adhesion of some kind of cells. PLA nanofiber nonwovens are hydrophobic. By certain laser processes, it was also possible to make this material more hydrophilic. It was observed, that the laser generated topography of the nonwovens plays a great rule in the wettability

Who cares about the digital culture at school?

The article assumes that the expansion of cultural content in basic education implies a qualitative change in the entire curriculum system. It rescues the idea of social micro spaces of common curriculum selection and reconfiguration and underlines the role of decision-makers in different groups. Namely, experts and specialists who, within the scope of the Learning Outcomes Project launched by the Portuguese Ministry of Education, supported the legitimation of ICT as a transdisciplinary learning area, consenting to shared responsibility in promoting digital culture. Based on the study carried out, involving 11 interviews, the article reveals the reasons that justify the detachment from a social practice that, paradoxically, was desired to be more articulated, integrated, and open to digital culture

Solar Salt Latent Heat Thermal Storage for a Small Solar Organic Rankine Cycle Plant

The design of the latent heat thermal storage system (LHTESS) was developed with a thermal capacity of about 100 kW h as a part of small solar plant based on the organic Rankine cycle (ORC). The phase change material (PCM) used is solar salt with the melting/solidification temperature of about 220 °C. Thermophysical properties of the PCM were measured, including its phase transition temperature, heat of fusion, specific heat, and thermal conductivity. The design of the thermal storage was finalized by means of the 3D computational fluid dynamics analysis. The thermal storage system is modular, and the thermal energy is delivered with the use of thermal oil, heated by Fresnel mirrors. The heat is transferred into and from the PCM in the casing using bidirectional heat pipes, filled with water. A set of metallic screens are installed in the box with the pitch of 8–10 mm to enhance the heat transfer from heat pipes to the PCM and vice-versa during the charging and discharging processes, which take about 4 h. This work presents a numerical study on the use of metallic fins without thermal bonding as a heat transfer enhancement method for the solar salt LHTESS. The results show that the absence of the thermal bonding between fins and heat pipes (there was a gap of 0.5 mm between them) did not result in a significant reduction of charging or discharging periods. As expected, aluminum fins provide better performance in comparison with steel ones due to the difference in the material conductivity. The main advantage observed for the case of using aluminum fins was the lower temperature gradient across the LHTESS

Academic literary canon and evaluation of reading of Literature: a study of Portuguese tests of year 12 (2013-2016)

Elegeu-se como núcleo de investigação a avaliação dos conhecimentos dos alunos do 12.º ano (período 2013-2016) no domínio da leitura do cânone escolar, cingindo-se esta análise documental à secção do exame consagrada à leitura literária e apoiando-se num quadro diversificado de dimensões, como a «Caracterização dos objetos de leitura» selecionados pelo avaliador, as «Estruturas textuais sobre as quais incidem as questões» ou as «Operações de leitura» solicitadas ao aluno. Os dados colhidos sugerem que, no exame de Português, se privilegia a avaliação de competências de leitura de textos literários de autores do cânone, como José Saramago, Fernando Pessoa, Luís de Camões e Sophia Andresen, sendo tais textos predominantemente poéticos e narrativos. Os itens dos questionários incidem apenas nas estruturas textuais do nível semântico-pragmático e são requeridas operações mentais como a Inferência, a Identificação e a Justificação. Constata-se, ainda, que o avaliador desvalorizou, a partir de 2014, a explicitação de juízos críticos dos alunos-leitores decorrentes da sua experiência de leitura de Literatura.CIED - Universidade do Minho; FCT - UID/CED/1661/2013info:eu-repo/semantics/publishedVersio

INTERFACES ENTRE HISTORIA DE MATEMÁTICAS Y ENSEÑANZA A TRAVÉS DE ANTIGUOS INSTRUMENTOS MATEMÁTICOS: UNA EXPERIENCIA EN LA INVESTIGACIÓN ACADÉMICA

Los estudios que cubren la relación entre Historia y Educación Matemática han suscitado varios debates, entre ellos, sus diferentes perspectivas pedagógicas y didácticas vinculadas a las posibles formas de abordarlas en el aula. Los vínculos entre historia, enseñanza y aprendizajepueden ofrecer recursos que reflejarán directamente la forma de concebir ciertos conceptos matemáticos. Entre algunas posibilidades, consideramos que el estudio de los aspectos teóricos y prácticos del conocimiento y los procedimientos involucrados en la construcción y uso de instrumentos matemáticos antiguos puede llevar al estudiante a comprender no solo el proceso de producción de conocimiento, sino también la formulación de conceptos matemáticos. Así, basado en una perspectiva historiográfica actualizada, este artículo es el resultado de la pasantíapostdoctoral relacionada con el proyecto "Construcción de interfaces entre la historia de las matemáticas y la enseñanza a través de instrumentos matemáticos antiguos para la elaboración de una propuesta didáctico-pedagógica dirigida a la enseñanza de conceptos matemáticos en educación básica ”, que tenía como objetivo principal investigar el instrumento científico en la articulación entre la historia de las matemáticas y la enseñanza con el fin de debatir y reflexionar, así como investigar, sobre las potencialidades didácticas de un antiguo instrumento matemático. Con este fin, proponemos presentar un informe centrado en la investigación, la experiencia docente y las propuestas teóricas desarrolladas en la pasantía postdoctoral en la Pontificia Universidad Católica de São Paulo (PUCSP) en el Programa de Estudios de Postgrado en Educación Matemática supervisado por el Prof. Dr. Fumikazu.Palabras clave: Interfaz entre la historia y la enseñanza de las matemáticas. Instrumentosmatemáticos. Petrus Ramus personal. AbstractStudies covering the relation between History and Mathematical Education have raised severaldebates, among them, their different pedagogical and didactic perspectives linked to the possible ways of approach in the classroom. The articulations between history, teaching, and learning can offer means that will reflect directly on how certain mathematical concepts are conceived. Among some possibilities, we consider that the study of theoretical and practical aspects of knowledge and procedures involved in the construction and use of old mathematical instruments may lead the student to understand not only the process of production of knowledge, but also the formulation of mathematical concepts. Thus, based on an updated historiographical perspective, this article is the result of the postdoctoral training course concerning the project “Building Interfaces between the History of Mathematics and Teaching through Old Mathematical Instruments for the Development of a Didactic-Pedagogical Proposal Teaching Mathematical Concepts in Basic Education ”whose main objective was to investigate thescientific instrument in the articulation between the history of Mathematics and teaching in orderto discuss and reflect, as well as to investigate, the didactic potentialities of an ancient mathematical instrument. To this end, we propose to present a report focusing on research, teaching experience and theoretical propositions developed in the postdoctoral internship at the Pontifical Catholic University of São Paulo (PUCSP) in the Program of Postgraduate Studies in Mathematical Education supervised by Prof. Dr. Fumikazu.Keywords: Interface between history and math education. Mathematical instruments. Baculumof Petrus Ramus. ResumoEstudos abrangendo as relações entre História e Educação Matemática vêm levantando diversos debates, dentre eles, suas diferentes perspectivas pedagógicas e didáticas ligadas aos possíveis caminhos de abordagem em sala de aula. As articulações entre história, ensino e aprendizagem podem oferecer recursos que irão refletir diretamente no modo de conceber certos conceitos matemáticos. Dentre algumas possibilidades, consideramos que o estudo de aspectos teóricos e práticos dos conhecimentos e dos procedimentos implicados na construção e no uso de antigos instrumentos matemáticos pode levar o discente compreender não só o processo da produção do saber, mas também da formulação de conceitos matemáticos. Dessa forma, baseado em uma perspectiva historiográfica atualizada, este artigo é resultado do estágio de pós-doutorado referente ao projeto “Construção de interfaces entre história da matemática e ensino por meio de antigos instrumentos matemáticos para a elaboração de uma proposta didático-pedagógica voltada para o ensino de conceitos matemáticos na educação básica” que tinha como objetivo principal investigar o instrumento científico na articulação entre história da Matemática e ensino com vistas a discutir e refletir, bem como investigar, sobre as potencialidades didáticas de um instrumento matemático antigo. Para tanto, propomos aqui apresentar um relato enfocando a pesquisa, experiência docente e proposições teóricas desenvolvidas no estágio pós-doutoral na Pontifícia Universidade Católica de São Paulo (PUCSP) no Programa de Estudos Pós Graduados em Educação Matemática supervisionado pelo Prof. Dr. Fumikazu.Palavras-chave: Interface entre história e ensino de matemática. Instrumentos matemáticos. Báculo de Petrus Ramus