bluuebunny/crossref_metadata_2025 huggingface dataset:
Entre igualdade e pluralismo: o constitucionalismo da diversidade na América Latina
Authors: Burckhart Thiago Rafael , Melo Milena Petters
Published: March 2020

O “novo constitucionalismo latino-americano” pode ser compreendido como um movimento político, jurídico, social e cultural relacionado com a refundação dos Estados da América Latina. Neste contexto destacam-se as Constituições mais recentes, Equador 2008 e Bolívia 2009, caracterizadas pela ampliação do rol de direitos fundamentais, com ênfase na diversidade política, econômica, social e cultural dessas sociedades, oferecendo uma significativa contribuição para a Teoria da Constituição e as reflexões sobre o patrimônio comum do constitucionalismo democrático. Este artigo, resultado de pesquisas realizadas a partir do método comparatístico em abordagem dialógica e situando-se no âmbito da Teoria da Constituição, com aportes de teorias do multiculturalismo e do pluralismo, dialogando com a teoria política e com a sociologia, objetiva trazer subsídios teóricos para refletir sobre o paradigma da diversidade nesse movimento, procurando responder ao questionamento: é possível se falar de um “constitucionalismo da diversidade” na região? O artigo conclui que é possível se falar e afirmar um “constitucionalismo da diversidade” e da solidariedade a partir das constituições analisadas, pautado na ressignificação do direito à igualdade e no reconhecimento das multifacetadas identidades. Tratam-se de inovações que se contrapõem à globalização neoliberal e que se projetam como desafios significativos para a prática política dos governos nacionais.
A extensão da plataforma continental brasileira além das 200 milhas marítimas: oportunidades e desafios
Authors: Lima Guaitolini Francisco , Quiroga Obregón Marcelo Fernando
Published: March 2020

O presente trabalho tem como objetivo investigar, a partir da Convenção das Nações Unidas sobre o Direito do Mar, o regime jurídico da plataforma continental e a sua possibilidade de extensão além das 200 milhas marítimas, prevista no artigo 76, abordando o funcionamento da Comissão de Limites da Plataforma Continental, bem como responder questões atinentes aos seus impactos econômicos na exploração de petróleo, gás natural e outros recursos minerais do leito e subsolo oceânicos sob direitos de soberania do Estado brasileiro, que compõem a Amazônia Azul. De igual modo, prevê-se sob a ótica do case brasileiro dificuldades quando a aplicação prática do artigo 82 da Convenção for submetida à prova dos fatos, o que realça a concepção de que exploração da plataforma continental estendida gerará uma série de oportunidades e desafios ao país.
A contribuição do movimento hip-hop no processo de valorização da cultura produzida na periferia
Authors: Costa Lucas Kaiser , Francischetto Gilsilene Passon Picoretti
Published: March 2020

A versão da história tida como oficial é contada pela perspectiva do vencedor. Acaba-se por ter uma visão histórica acrítica e justificadora de várias barbáries cometidas ao longo da humanidade, notadamente contra a população negra. Essa visão, além de parcial, não raras vezes tratou – e trata – de invisibilizar as suas experiências, caracterizando-as como não-existentes ou não-credíveis. Dentro desse panorama histórico que constrói a sociedade e incute subjetividades, os indivíduos são forjados a partir de preceitos sociais racistas, sexistas, homofóbicos, etc. Nessa perspectiva é que essas populações invisíveis buscam emergir, notadamente na sua autovalorização como forma de contracultura e contrapoder, na utilização contra-hegemônica do seu próprio saber. Assim, através de uma análise teórica, o presente artigo pretende investigar a contribuição do movimento hip-hop no processo de valorização da cultura produzida na periferia, verificando como se dá a construção da identidade hip-hop e os processos de invisibilização e as possibilidades que se abrem na vida do jovem negro da periferia, perpassando pela história do movimento até a sua chegada ao Espírito Santo e sua interrelação com o Direito. Propõe-se, contribuir com o debate, investigando o potencial do hip-hop, para se concluir o movimento como verdadeiro campo de possibilidades para um amanhã diferente.
Traços do positivismo jurídico no pensamento hobbesiano: uma leitura a partir dos pensadores contemporâneos
Authors: Balera José Eduardo Ribeiro , Cambi Eduardo
Published: March 2020

O pensamento hobbesiano influenciou de modo substancial a filosofia política e jurídica ao longo da história e ainda se mantém presente, direta ou indiretamente, em diversas abordagens acerca da ordem estatal e sua interação com a sociedade civil. O presente trabalho tem por objetivo delinear uma aproximação do pensamento de Thomas Hobbes à teoria do positivismo jurídico, por meio da análise da obra Leviatã ou Matéria, Forma e Poder de um Estado Eclesiástico e Civil (1651). Inicialmente, serão apresentados elementos basilares da teoria do direito quanto ao positivismo jurídico por meio das considerações do filósofo norte-americano Ronald Dworkin e do pensador italiano Norberto Bobbio. Em seguida, serão examinados aspectos de maior relevância da filosofia política hobbesiana que permitam vislumbrar sua caracterização na qualidade de uma teoria positivista, como a concepção de leis de natureza enquanto preceitos prudenciais, a sujeição à legislação civil e ao poder decisório da autoridade soberana perante a ordem jurídica vigente.
Tunable mode-locked erbium-doped fiber laser based on a digital micro-mirror device
Authors: Wang Whenhao , Tian Meng , Yang Yan , Huang Yanhua , Li Cong , Chen Guoliang , Lv Min
Published: March 2020

A tunable mode-locked erbium-doped fiber laser with a digital micro-mirror device (DMD) as the wavelength tuner and nonlinear amplifying loop mirror as the mode-locked device is proposed and experimentally demonstrated. The mode-locked pulse with the center wavelength of 1538–1565 nm continuously tunable is achieved. The average power of the output pulse is 1.028 mW, the pulse repetition frequency is 1.7 MHz, the pulse duration is 616 fs, and the single pulse energy is 0.6 nJ. By controlling the DMD, the center wavelength can be fine-tuned with the tuning accuracy of 0.07 nm. With the increase of the pump power, the traditional soliton pulse is transformed into a noise-like pulse (NLP), and the power of the NLP can reach 34 mW. This mode-locked process can work for a long time and is almost unaffected by the external environment. These results are very useful for applications where pulsed lasers with different wavelengths are needed.
Density functional theory study of mixed halide influence on structures and optoelectronic attributes of CsPb(I/Br)3
Authors: Jbara Ahmed S. , Munir Junaid , Ul Haq Bakhtiar , Saeed M. A.
Published: March 2020

This paper reports on the influence of the bromine (Br) atoms substitution on the structures and optoelectronic traits of

CsPbI
3

, wherein the density functional theory (DFT) simulation was performed, using all electrons full potential linearized augmented plane-wave method. Furthermore, the generalized gradient approximation, local density approximation, and modified Becke–Johnson exchange-correlation potential were used to improve the optimization and band structure calculations. The calculated lattice constants of

CsPbI
3

and

CsPbBr
3

were consistent with the experimental values. All the studied compounds revealed wide and direct bandgap energies at the R-symmetry point, which varied from 1.74–2.23 eV. The obtained refractive indices of the

CsPbI
3

,

CsPbBrI
2

,

CsPbIBr
2

, and

CsPbBr
3

compounds were correspondingly 2.265, 2.245, 2.090, and 2.086. Present findings may contribute towards the development of experimental studies on the proposed compounds with controlled properties useful for the solar cells.
Micromirror array allocation algorithm based on deconvolution
Authors: Liu Zhifan , Yang Chaoxing , Bu Yang , Li Sikun , Zhang Jianhua , Wang Xiangzhao , Sun Gang
Published: March 2020

Freeform illumination is one of the necessary techniques in 28 nm technology nodes and beyond. The micromirror array (MMA) has been widely used in lithography freeform illumination systems due to its programmability and high free degree. The MMA allocation algorithm is the key to generate the target freeform illumination source. Its computational speed and precision affect the generation speed and precision of the target illumination source as well as the process window size of the generated illumination pupil directly. In this paper, an MMA allocation method based on deconvolution is proposed. The target freeform illumination source can be obtained directly with the deconvolution and quantization processes. Without the iterative optimization process, the computational speed of the proposed method is much faster than that of the traditional method. The numerical simulation results show that the difference between the target source and the MMA source generated using the proposed method is less than 0.2%. Compared with the process window loss of the target source, the process window loss of the MMA source generated by the proposed deconvolution method is less than 0.5%. Compared with the traditional allocation method, the runtime of the proposed method is less than 0.05 s and has improved by 1463 times.
Erbbaurecht als Anlageform für institutionelle Investoren
Authors: Sebastian Steffen , Wagner Dominik , Fritz Carsten
Published: March 2020

Das Erbbaurecht ist eine probate Alternative zum klassischen Volleigentum. Vorrangig von Kommunen und Stiftungen angewandt, ist diese Form der Grundstücksteilung in vielen entwickelten Ländern die typische Form des Immobilienerwerbs. Vor dem Hintergrund des niedrigen Zinsumfelds suchen institutionelle Investoren nach alternativen Anlagevehikeln mit zufriedenstellenden Rendite-Risiko-Verhältnissen. Diese Arbeit untersucht die Marktakzeptanz des deutschen Erbbaurechts sowie mögliche Einflüsse aus Großbritannien als einem der höchstentwickelten Märkte für Erbbaurecht. Unsere Analyse zeigt, dass das Erbbaurecht ein sinnvolles Nischenprodukt für institutionelle Investoren zur Generierung von Mehrwerten darstellt. Der individuelle Nutzen für Investoren mit deutschem Investmentfokus hängt jedoch stark von der konkreten Vertragsgestaltung ab. Der britische Markt stellt für deutsche Immobilienfonds aktuell aufgrund der höheren Liquidität und Transparenz des Marktes eine geeignetere Anlageallokation dar.
Píldoras formativas para la mejora educativa universitaria: el caso del Trabajo de Fin de Grado en el Grado de Lingüística y Lenguas Aplicadas de la Universidad de Cádiz
Authors: Crespo Miguel Mario , Sánchez-Saus Laserna Marta
Published: March 2020

Este trabajo presenta el proyecto de innovación Píldoras formativas para la mejora del Trabajo de Fin de Grado en el Grado en Lingüística y Lenguas Aplicadas realizado durante el curso 2017-2018 en el contexto del Grado de Lingüística y Lenguas Aplicadas de la Universidad de Cádiz. Este proyecto se enfoca hacia el desarrollo o de tutoriales audiovisuales de corta duración o píldoras formativas sobre aspectos metodológicos del Trabajo de Fin de Grado, debido a los problemas que la realización de este trabajo suscita en nuestros alumnos. En este artículo se examinan las características de este tipo de trabajos académicos, se exploran tanto los hábitos y expectativas de uso de las redes sociales y los recursos audiovisuales, y se indaga sobre la percepción que tienen sobre ellas los estudiantes cuando buscan información. Finalmente, se analizan los déficits observados en los alumnos por los profesores a la hora de realizar este tipo de trabajos y las posibilidades de mejora que estos recursos ofrecen en el proceso de enseñanza-aprendizaje.
Catálogo de lineamientos metodológicos para apoyar el proceso de aprendizaje colaborativo
Authors: Agredo-Delgado Vanessa , Ruiz Melenje Pablo Hernando , Collazos César Alberto , Moreira Fernando , Fardoune Habib M.
Published: March 2020

El uso de las modernas tecnologías de la información y la comunicación se ha convertido en una de las ideas más prometedoras para mejorar la enseñanza y el aprendizaje. Un ejemplo es el aprendizaje colaborativo apoyado por computadora, que se ocupa de estudiar cómo las personas pueden aprender en conjunto con la ayuda de computadoras y que, si se implementa de manera adecuada, puede proporcionar un entorno ideal en el que la interacción entre los estudiantes juega un papel importante en este proceso de aprendizaje. Sin embargo, la actividad de desarrollo en un grupo con el uso de una herramienta no garantiza una colaboración correcta y, además, otro problema aparente es: para los educadores es más fácil seguir las prácticas aceptadas que abrir nuevos caminos que reemplacen el modelo de tutoría tradicional, con algo radical como el trabajo en grupo con la ayuda de las computadoras. Por esta razón, es necesario tener elementos que digan qué y cómo apoyar el proceso de aprendizaje colaborativo para mejorar la colaboración y las acciones de los maestros. En este documento, proponemos un catálogo de lineamientos metodológicos para resolver estos problemas, que son una solución recurrente a un problema estándar que ayudan a comunicar y reutilizar el conocimiento en este contexto, proporcionando grandes beneficios para el desarrollo de actividades de aprendizaje colaborativo reutilizables, flexibles y personalizables. De acuerdo con la validación, se puede considerar que nuestra propuesta es útil, aplicable y fácil de usar en la aplicación de actividades colaborativas y con su uso, la colaboración mejora.
The breach of contractual indemnities under English law – a debt claim or a damages claim?
Authors: Chukwu Febechi
Published: March 2020

In 2015 the English High Court delivered two important but not widely publicised judgments in the cases of ABM Amro Commercial Finance plc v Ambrose McGinn & others [2014] EWHC 1674 (Comm.) and Durley House Limited v Firmdale Hotels plc [2014] EWHC 2608 (Ch.). Febechi Chukwu reviews those judgments, and several previous rulings by the English courts, concluding that the lack of a single interpretive rule for contractual indemnities in English law is a preferable approach. The English courts should be clearer in accepting the complexity of properly interpreting indemnities and assessing the available remedies for breach. Ultimately that assessment is substantially dependant on how the indemnity in question is drafted and constructed in the contract. The courts should boldly promote the more nuanced approach to determining whether a particular breach gives the innocent party a right to a claim in debt or a claim in damages, and this will be of benefit also to practitioners negotiating indemnity clauses in English law contracts.
Editorial Board and Associate Editors
Authors: Harave Narayana
Published: March 2020

Editorial Board and Associate Editors
PERFORMANCE ANALYSIS OF QUADRATURE CHAOS SHIFT
Authors: Alabbasi Hesham Adnan , Abboud Izz Kadhum , Hasan Fadhil Sahib
Published: March 2020

One of the most famous techniques of non-coherent differential chaos shift keying (DCSK) is Quadrature chaos shift keying (QCSK) system, this system suffered from lowering the data rate and increasing the bit energy during the bit transmission even though its rate doubling the one of the DCSK. Short reference (SR) algorithm is proposed for the QCSK system to design the SR-QCSK communication system that enhances these drawbacks. The main idea of the short reference technique is minimizing the length of the reference chaotic signal (β) at a transmitter by a factor P comparing to produce R samples for the new reference signal while the length of the information-bearing signal remained unchanged, this occurs by duplicating the reference signal P times to get the same length as the conventional QCSK. Therefore, the symbol duration is reduced from 2βTc to (R+β)Tc. The data rate and energy saving improvement factor in a percent form is derived and compared with the QCSK and DCSK systems. Also, the BER analytical expression is derived for the SR-QCSK in additive white Gaussian noise and Rayleigh fading channel. The experimental simulation results proved that the theory derivation gives a good analysis tracking for the BER performance. The SR-QCSK system is compared with other DCSK techniques and the simulation results show that it has a superior performance in the multipath Rayleigh fading channel.
ANALYSIS OF STATIC ANGLE OF REPOSE WITH RESPECT TO POWDER MATERIAL PROPERTIES
Authors: Macho Oliver , Demková Karin , Gabrišová Ľudmila , Čierny Matúš , Mužíková Jitka , Galbavá Paulína , Nižnanská Žofia , Blaško Jaroslav , Peciar Peter , Fekete Roman , Peciar Marián
Published: March 2020

This paper investigates the Angle of Repose (AoR) of powder materials with respect to their morphological and rheological properties. Glass beads, sand, flour and semolina of different particle sizes were used as the experimental materials. The investigated material was analysed with respect to particle shape and size. The rheological properties of the material were obtained by a shear cell test. The AoR was analysed in terms of cohesion, bulk density, particle size and circularity. More cohesive materials such as the flour samples exhibited the largest AoR > 40°, indicating their poor flowability. Glass bead samples with a high circularity value had significantly lower AoR than the flour. The Angle of Internal Friction values were not dependent on those of the AoR. Using a dimensional analysis, a mathematical model was developed to determine the AoR values based on the material properties. By the application of this model, highly accurate calculation of the value of AoR is made possible.
Concepções e discursos sobre a docência: tensões, embates e perspectivas
Authors: Silva Edileuza Fernandes , Bento André Lúcio
Published: March 2020

Analisam-se concepções acerca da docência expressas na Resolução nº 2, de 1º de julho de 2015, na Portaria nº 38, de 28 de fevereiro de 2018 e em narrativas de três professores de cursos de licenciatura de uma instituição de ensino superior pública da região Centro-Oeste. A discussão é parte de estudo qualitativo em desenvolvimento sobre a formação didático-pedagógica de professores para a Educação Básica, cujos dados foram obtidos de documentos e entrevistas narrativas. As análises preliminares indicam que os documentos apresentam discursos e concepções de docência, articulados aos contextos social, político, econômico e educacional de sua elaboração. Os docentes que formam professores, compreendem a docência relacional como processo de trabalho coletivo, influenciada pelas experiências pessoais e acadêmicas. Há ainda a identificação da docência como sacerdócio e orientada pela pesquisa, expressando uma ambiguidade conceitual.
Epistemologia, Currículo e Formação Continuada de Professores de Ciências
Authors: Silva Paulo Sérgio Araújo da
Published: March 2020

Este trabalho trata de investigação desenvolvida durante processo de formação continuada de professores de ciências (das disciplinas Química, Biologia, Física e Ciências da Educação Básica) em uma universidade pública. Consiste em pesquisa narrativa por meio da qual se busca compreender relações entre reflexão epistemológica e formação docente. Procurou-se, particularmente, investigar que tipos de reflexões os sujeitos-professores constroem a partir da introdução de discussões relativas ao processo de produção, validação e apropriação social do conhecimento científico e as relações que estabelecem com suas histórias de atuação e formação pessoal e profissional. A análise do conjunto de materiais produzidos sinaliza que a ação recursiva da memória, estimulada a partir de discussões epistemológicas no presente, potencializou as reflexões docentes em quatro dimensões principais: Ético-política; Curricular, Metodológica e Afetiva, a discussão empreendida neste artigo se refere à dimensão curricular.
Professores como intelectuais e a construção coletiva de conhecimentos didáticos
Authors: Pacievitch Caroline , Oliveira Amanda Gabriela Rocha
Published: March 2020

O objeto de estudo deste artigo é a formação continuada de professores de História a partir da produção coletiva de conhecimentos didáticos no Programa Institucional de Bolsa de Iniciação à Docência - Pibid História, com foco no processo de interlocução e produção coletiva desses conhecimentos envolvendo professores experientes e estudantes de licenciatura em formação. A problemática de fundo é como se aprende a ensinar História a partir da concepção de professores como intelectuais transformadores, conforme Henry Giroux. Os resultados auxiliam a demonstrar que o grupo de bolsistas de iniciação à docência e supervisores conseguiu realizar a construção coletiva de conhecimentos didáticos, além de explorar as relações entre perfil profissional e escolhas didáticas realizadas ao longo da pesquisa.
Professores de ensino médio: condições de trabalho e características formativas de uma categoria profissional silenciada
Authors: Mesquita Silvana Soares de Araujo
Published: March 2020

Este trabalho investiga o professor de ensino médio, procurando identificar as especificidades dessa categoria profissional quanto à formação e às condições de trabalho. Resulta de pesquisa qualitativa, desenvolvida em uma escola pública da rede estadual, na periferia do Rio de Janeiro. Foram aplicados questionários a 69 professores e realizadas entrevistas, além de observações do campo. Dialoga com pesquisas nacionais e internacionais sobre o ensino médio e a formação (Oliveira, Costa, Kuenzer, Gatti, Dubet, Nóvoa e Formosinho). O texto se estrutura em três partes: Condições de trabalho_um quadro de intensificação; Relações de gênero e tempo de serviço_a “tensão” entre grupos heterogêneos; Formação dos professores_múltiplas influências e representações. Conclui-se que as condições de trabalho e a formação desses professores precisam ser repensadas, para superar a própria lógica organizacional e temporal do ensino médio e do estatuto profissional previsto, visando o desenvolvimento da profissional desta categoria docente.
A utilização de tecnologias digitais no Curso de Licenciatura em Matemática PARFOR/EaD da Universidade Federal de Uberlândia
Authors: Gonçalves Elivelton Henrique , Marco Fabiana Fiorezi de
Published: March 2020

Esta pesquisa empreendeu esforços no estudo das Tecnologias Digitais (TDs) na formação de futuros professores de Matemática na modalidade a distância, e foi conduzida pela seguinte questão: como as Tecnologias Digitais são metodologicamente abordadas pelos professores no Curso de Licenciatura em Matemática, na modalidade a distância, da Universidade Federal de Uberlândia? Buscando resposta a esse questionamento, foram propostos os objetivos: analisar como professores organizaram o ensino das suas disciplinas abordando as TDs, e analisar como os licenciandos e tutores avaliaram essa abordagem. Como metodologia, a partir da abordagem da pesquisa qualitativa, realizou-se entrevistas com professores e propôs-se questionários aos licenciandos e tutores. Os resultados evidenciaram a importância da proposição de situações formativas que não apenas apresentem as TDs aos licenciandos, mas, também, que permita-os construir conhecimentos sobre sua integração, enquanto ferramentas de ensino, na sala de aula de Matemática.
Estado, Políticas Públicas e Formação Docente no Brasil: direcionamentos a partir do início do século XXI
Authors: Molina Adão Aparecido , Rodrigues Adriana Aparecida
Published: March 2020

A educação e a formação docente precisam ser compreendidas a partir de uma vertente totalizante, estabelecendo-se uma relação com a economia e a política, cuja finalidade é perceber as contradições e as ideologias presentes nas políticas educacionais em geral. Partindo desse princípio, o objetivo deste estudo é apontar o papel do Estado nas políticas públicas para a educação no Brasil a partir do inicio do século XXI, enfatizando as políticas destinadas à formação docente. Para atender tal proposto, a pesquisa se pautou em um estudo bibliográfico, por meio de uma concepção teórica pautada no materialismo histórico e dialético. Os resultados mostraram que, as políticas públicas destinadas à formação docente no Brasil estão imbricadas com a forma de organização e de administração do governo federal, consequentemente com as determinações socioeconômicas e políticas que regem as ações governamentais do país.
Proposições conceituais em torno da formação e do trabalho docente: uma orientação emancipatória para o desenvolvimento profissional
Authors: Almeida Maria Isabel de , Fernandes Tiago Rufino
Published: March 2020

Com base em pesquisa que investigou possibilidades para o desenvolvimento profissional de professores em um curso de formação, defende-se uma articulação entre os conceitos de desenvolvimento profissional, formação continuada e trabalho docente como quadro referencial para pesquisas sobre formação. Tomando como referências centrais autores como Marx (2013), Nóvoa (1995, 2000, 2009), García (2003, 2009), Almeida (1999) e Contreras (2012), após realizar uma revisão da produção bibliográfica sobre o tema da formação de professores, apresentam-se algumas linhas de força da articulação conceitual pretendida. O objetivo é oferecer um conjunto de orientações e princípios teórico-conceituais para a abordagem dos temas que se referem ao desenvolvimento profissional docente com orientação emancipatória.
Expectativas e medos de professores em formação: o papel do estágio supervisionado de ensino
Authors: Silva Delano Moody Simões da , Pedreira Ana Júlia
Published: March 2020

O estágio supervisionado é desencadeador de uma série de emoções nos estudantes, como expectativas, medos e angustias com relação à sua realização. O conhecimento desses sentimentos por parte dos formadores de professores poderia ajuda-los na abordagem dos mesmos ao longo do processo de formação, antecipando ou discutindo situações que contribuam para diminuir os possíveis efeitos negativos desses. O objetivo desse estudo foi identificar as expectativas e medos de um grupo de licenciandos em Ciências Naturais, na primeira disciplina de estágio supervisionado e discutir a influência dessa disciplina no enfrentamento desses sentimentos. Os estudantes indicaram mais medos que expectativas no primeiro dia de aula quanto à realização do estágio. A partir da análise de conteúdo percebemos, nas indicações, que o momento de estágio realmente é cercado de muita tensão e apreensão. Enfrentar esses sentimentos no contexto escolar, sob orientação de professores supervisores pode ser determinante para a carreira do futuro professor.
Contribuições da formação doutoral para a construção da identidade docente
Authors: Freitas Nadia Magalhaes da Silva , Abreu Josyane Barros
Published: March 2020

Objetivamos apreender as contribuições da formação doutoral para a construção da identidade docente. Na pesquisa, de natureza qualitativa, realizamos entrevista estruturada, modalidade projetiva, junto a docentes, egressos de um programa de doutorado, lançando dois questionamentos, a saber: como você identifica o/a professor(a) que é/tem sido? Que contribuições a experiência doutoral forneceu para essa identificação? Os dados constituídos foram analisados mediante Análise Textual Discursiva. Os docentes manifestaram dificuldades para auto identificar-se, configurando um movimento que intitulamos de problematização de si. Dentre as contribuições do doutorado, para a tecitura da identidade profissional docente, destacamos as seguintes: reconhecer-se insuficiente, constituição de um professor que reflete na/e sobre a prática docente, postura de um professor investigativo etc. Entendemos que a vivencia doutoral representa campo fértil para o desenvolvimento profissional docente, na medida em que protagoniza uma destruição criadora de sua identidade, podendo superar antigas formas de professorar para, então, substituí-las por outras mais inovadoras.
MULTI-FUNCTIONAL CEMENTITIOUS COMPOSITES WITH SENSING AND HEALING CAPABILITIES
Authors: Siad Hocine , Lachemi Mohamed , Sahmaran Mustafa , Hossain Anwar
Published: March 2020

For smart concretes to be developed, it must be gathering high mechanical and durability properties, in addition to satisfying special characteristics such as self-monitoring of damage. This study outlines attempts to develop advanced Engineered Cementitious Composites (ECC) with combined self-sensing and self-healing capabilities. The aim is to maintain or improve the high mechanical and ductility properties of ECC, while enhancing the self-monitoring and self-healing capabilities. To assure the self-sensing functionality, carbon-based materials with different volumes were incorporated in ECC formulations. The self-healing rates of control and piezoresistive ECC’s were assessed by pre-cracking specimens up to 60% of their original flexure deformations and left those samples to heal under moist curing. The mechanical performances and ductility were evaluated based on compressive and flexural strengths, and mid-span beam deflection capacity measurements. The self-healing/self-sensing efficiency was tested by assessing the electrical resistivity (ER) variations of cylindrical specimens. Mechanical results of carbon-based ECC mixtures showed better or comparable performances than the corresponding control ECC. This study also reveals that the type of carbon-based materials and moisture state of specimens considerably influence the self-sensing/self-healing ability of ECC mixtures.
STUDY ON DETECTION METHOD OF DEFECTS IN COVERED CONCRETE USING ELECTRICAL RESISTIVITY MEASUREMENT
Authors: Kawaai Keiyu , Ujike Isao , Okuno Hiroshi
Published: March 2020

This study reports on a fundamental study on the investigation of electrical resistivity measurements for detecting internal defects or damages, which aims at developing Electrical Resistance Tomography techniques based on electrical resistivity distribution measured via Wenner method. In particular, this study examined the changes of resistivity upon the presence of damages in the bottom of concrete specimens which mirror internal cracking not visually observed on the concrete surface in typical reinforced concrete structure. For the experimental investigation, ten electrodes comprising stainless steel and electric conductive epoxy were partially embedded on the surface of prism concrete specimen. Then, electrical resistivity was measured via Wenner method using four electrodes selected among the electrodes placed 20 mm apart each other. In addition, analytical investigation simulating the influence of internal damages on current flow and measured voltage or potential was carried out by FEM analysis. As a result, electrical resistivity increased depending on the depth of slits with 1 mm width, which was sawed at the bottom of the specimen. This could be attributed to the influence of the damages on the current flow and equipotential planes, thus suggesting that there is a good possibility that internal damages can be detected based on the changes and the distributions of the electrical resistivity.
CHARACTERISTICS OF FRESH MIXTURE OF A NOVEL CEMENT-LESS WASTEPAPER-BASED LIGHTWEIGHT BLOCK AND ITS MOLDING PROCESSES
Authors: Okeyinka Oriyomi M. , Oloke David A. , Khatib Jamal M.
Published: March 2020

Cement-less wastepaper-based lightweight block (CWLB) is an eco-friendly lightweight non-loadbearing block newly developed from majorly waste materials. As part of efforts to enable the understanding of its mixture proportioning and production processes, this study presents the characteristics of its fresh mixture and its peculiar molding process. The fresh mix characteristics studied include; the texture, density, elastic modulus, percentage void/porosity and the peculiar molding process. The laboratory experimentation conducted covers; the preparation of the CWLB mix (from mixture of wastepaper aggregate (WPA), sand, waste additive, natural admixture and water), determination of physical and deformation properties of the mix and the molding of CWLB specimen. It was found that, for the mixes tested, the fresh mixture of CWLB is fibrous in texture, voluminous in nature and exhibits an average loose bulk density of 305.3 kg/m3. Also, average compacted bulk density of 857.6 kg/m3 and 792.38 kg/m3, elastic modulus of 30.28 MPa and 28.38 MPa and percentage void of 77% and 76% (i.e., porosity of 0.77 and 0.76) were recorded for mixes containing 52% and 36% sand content (measured by weight of WPA) respectively. The molding procedure for CWLB was thus found to be slightly different from those available for conventional masonry blocks in terms of relationship between the mold size, mixture quantity and resulting specimen size. These findings therefore indicate the peculiarity of the physical and deformation properties of the fresh mixture of CWLB and the importance of awareness and understanding of same for efficient production of CWLB. Future work will involve the development of suitable numerical expression for determining the in-mold mass requirement for molding a typical CWLB sample and the design of an innovative, undemanding, cost and energy efficient manufacturing kit for CWLB.
SELF-HEALING CONCRETE USING FLY ASH
Authors: Ishikawa Yoshitaka
Published: March 2020

In recent studies, it has been recognized that concrete deterioration is accelerated by growth of the fine cracks of a few micron meter wide which was induced by dry shrinkage and/or freezing damage. Research of the concrete which carries out self-healing of these fine cracks has been abundantly expected. To confirm the ability of fly ash on self-healing, we conducted fundamental test of mortar using fly ash (replacement ratio: 20%) which was deteriorated by accelerated freeze-thaw cycle until the relative dynamic modulus of elasticity reduced to 80% and 60%. The mortar specimens were then cured in water at 40°C and 20°C. We have evaluated the self-healing degree of the cured mortar specimens by strength test, some durability tests, and concrete structure observations. From the test results, it was confirmed that fly ash functioned effectively as a self-healing material of concrete.
THEORETICAL APPROACH TO DETERMINATION OF ACOUSTIC PROPERTIES OF BUILDING MATERIALS
Authors: Fiala Lukáš , Černý Robert
Published: March 2020

The presence of high level of acoustic load especially in urban areas is becoming a serious problem in the present. In order to protect people against adverse effects of audio noise on health and personal well-being in buildings located in such areas, convenient construction materials with sophisticated geometric arrangement should be used. Bearing structures of new houses in the Czech Republic are widely made of different types of brick blocks. Such brick blocks consist of solid matrix and cavities designed in an optimized geometrical way in order to assure better thermal and hygric properties. Previous studies dealing both with acoustic properties in an empirical way and with the theoretical aspects of acoustic attenuation in building materials were not very numerous. Nevertheless, they gain constantly in importance with increasing acoustic load of the buildings surroundings. In this paper, a theoretical approach for the determination of acoustic properties, which is convenient for the description of sound waves propagation in building materials, is introduced.
USE OF PPP IN DIFFERENT COUNTRIES AND REGIONS
Authors: Gurgun Asli Pelin , Polat Gul , Bayhan Hasan Gokberk
Published: March 2020

Public Private Partnership (PPP) projects are being implemented by governments for similar reasons across the globe, such as removing the responsibility of funding the investment from the government´s balance sheet, introducing competition, benefiting from the expertise, experience and technology of the private sector that would lower the project delays and cost overruns. Despite sharing common motivation factors in pursuing PPP projects, the development trends, models used, legal context and legislations differ from one country to another. Depending on country’s needs and political atmosphere, governments decide on the sector, where they want to use PPP and the appropriate PPP model to execute their projects. In this study, a comparative study is conducted to underline main differences and similarities between PPP practices in different parts of the world. The comparisons are based on diversification of infrastructure needs and investment sectors, legal context and PPP models used. This study investigates how use of PPP projects differs from one country to another and regions in the world. Similarities are also analyzed to summarize the state of the art of PPP practices to provide a global approach.
ROAD SAFETY AUDIT: A CASE STUDY
Authors: Aydin Cumhur , Balla Nura
Published: March 2020

As a consequence of increasing traffic volume and mobility, road accidents have been a serious problem especially in low and middle-income countries. The number of road accidents in such countries tends to increase every year. Considering different contributing factors to the road accidents, road and its environment have played an important role. Road safety audits and road safety inspections have been worldwide used tools to monitor and to evaluate road projects and existing road sections from the safety perspective. In this study, through the evaluation of different safety auditing techniques applied in the world, a case study on a Nigerian Road Section has been implemented. The expectations from such a study are: (i) To show the main safety deficiencies of the Nigerian road sections; and (ii) To introduce a new tool to the local road authorities to further use it for monitoring their road sections. Based on this study, the audit report was prepared to summarize findings with possible countermeasures.
MICROSTRUCTURE, TEXTURE, AND MECHANICAL PROPERTIES OF GEOPOLYMERS PREPARED USING INDUSTRIAL WASTE
Authors: Čáchová Monika , Koťátková Jaroslava , Rovnaníková Pavla , Doleželová Magdaléna , Alblová Nikol , Svora Petr , Vejmelková Eva , Kočí Václav , Černý Robert
Published: March 2020

Geopolymers prepared by processing industrial waste present an environmental friendly alternative to the traditional binders which are characterized by very energy-demanding production. Due to an appropriate composition, fine-ground ceramic powder represents a good candidate for the production of geopolymers. In this paper, microstructure, texture, basic physical properties and compressive strength of three geopolymers with different silicate modulus (SM) are studied. Experimental results showed that the densest microstructure had the material with the lowest SM = 0.8, which also did not have any visible cracks. The open porosity and matrix density were found to increase with the increasing SM. The highest compressive strength was reached for the highest SM = 1.2. Having the compressive strength of ~38 MPa, such a geopolymer can be considered as comparable to cement based materials.
DISASTER IMAGINATION GAME ENHANCED BY MOBILE MAPPING SYSTEM AND ITS APPLICATION
Authors: Tsujihara Osamu , Yamaguchi Kyohei , Ito Hideyuki , Sato Tomoyuki , Okamoto Terumasa
Published: March 2020

DIG (Disaster Imagination Game) is known as one of the risk communication methods in Japan. The participants who live in the same area surround a map of the area and discuss the disaster information such as the evacuation routes and the dangers that may lie around. They try to find not only the hazards but also the useful information like the location of the shelter. The detected information is illustrated in the map with pens and seals to visualize the risk and help. Thus the information in the area is shared with the participants. In this study, the new developments are proposed in which the serial video captured by MMS (Mobile Mapping System) is used as well as the map. The combination of the map and the serial video helps to detect the hazards. Moreover, the hazards detected in the workshop are illustrated not only on the map but also in the serial video. The effectiveness of the proposed system is discussed through the application to the practice of DIG.
KNOWLEDGE-BASED PORTFOLIO MANAGEMENT: A TAXONOMY FOR LESSONS LEARNED
Authors: Eken Gorkem , Bilgin Gozde , Dikmen Irem , Birgonul M. Talat
Published: March 2020

Portfolio management comprises of identifying, prioritizing, authorizing, managing, and controlling projects, programs, and other related work to achieve specific strategic business objectives. Utilizing a knowledge-based portfolio management approach can be a critical success factor for construction companies. This research aims to present a taxonomy to facilitate the learning process within a knowledge-based project portfolio management system. The taxonomy is capable of codification and classification of lessons revealed during life cycle of projects to enhance their retrieval. Within this context, following a detailed literature review process, the taxonomy is structured under four main categories as "project", "process", "actor", and "resource”. Categories provided in the taxonomy enable tagging of the lessons learned according to the intended level of detail, facilitate retrieval and reuse of the lessons learned in forthcoming projects. In this paper, we will present the structure of the proposed taxonomy and discuss how it can be used to improve portfolio management in construction.
WIND PRESSURE DISTRIBUTION ON CIRCULAR CANOPY ROOFS
Authors: Rani Neelam , Ahuja Ashok Kumar
Published: March 2020

The present study gives information related to wind pressure distribution on single span and multi span circular canopy roofs. The experiments are carried out in an open circuit boundary layer wind tunnel. Wind pressure is measured on both upper and lower roof surfaces of circular canopy roof model made of Perspex sheet. Models are tested under varying wind incidence angles between 0° and 90° at an interval of 15° on isolated model and 0° to 180° at an interval of 30° on models with multi-span canopy roof. Values of mean wind pressure coefficients are evaluated from the measured values of wind pressures. Results of the study are presented in the form of contours, cross sectional variation and face average values of pressure coefficients. The results of the study are of great use for the structural designers for designing circular canopy roofs.
BRITTLE/DUCTILE ASSESSMENT OF HYBRID REINFORCED CONCRETE BEAMS CONTAINING STEEL REBAR AND FIBERS
Authors: Fantilli Alessandro P. , Gorino Andrea , Chiaia Bernardino
Published: March 2020

Many structures, such as precast and cast-in-situ tunnel linings, are nowadays realized with Hybrid Reinforced Concrete (HRC), where a combination of continuous steel rebar and discrete fibers is used to reinforce the cementitious matrix. Hence, the definition of a minimum amount of hybrid reinforcement (i.e., rebar and fibers), which prevents the brittle failure, is of practical interest. For predicting the brittle/ductile response of HRC beams in bending, a theoretical model is introduced and presented in this paper. It is based on the flexural response of both Lightly Reinforced Concrete (LRC) and Fiber-Reinforced Concrete (FRC) beams, separately analyzed. The numerical results of the model, and some experimental data as well, show that the minimum reinforcement of HRC beams can be determined with a new design procedure. It requires the definition of the ductility index (DI), which is proportional to the difference between ultimate and effective cracking load. As DI linearly increases with the amount of rebar and fibers, the minimum reinforcement in HRC members can be found when DI is equal to zero. In addition, the minimum hybrid reinforcement can be defined with a suitable linear combination of the minimum area of rebar and the minimum fiber volume fraction, related to LRC and FRC beams, respectively.
NUMERICAL ANALYSIS OF CONCRETE BEAM REINFORCED WITH GLASS FIBER REINFORCED POLYMER BARS
Authors: Mohamed Osama A. , Khattab Rania
Published: March 2020

The use of fiber reinforced polymer (FRP) bars to reinforce concrete beams has received significant attention in the past decade due to their corrosion resistance, high tensile strength, and excellent non-magnetic properties. Glass FRP (GFRP) reinforcing bars have gained popularity due to the relatively lower cost compared to carbon FRP (CFRP) bars. In this study, sixteen concrete beam finite element models were created using the finite element computer program ANSYS to perform linear and non-linear analyses. Twelve beams were longitudinally reinforced with GFRP bars, while the remaining four beams were reinforced with conventional steel bars as control specimens. In terms of mechanical properties, FRP reinforcing bars have lower modulus of elasticity compared to conventional reinforcing steel and remain linear elastic up to failure. This leads to lack of plasticity and a brittle failure of beams reinforced with FRP bars. The objective of this study is to investigate flexural behavior of concrete beams reinforced with GFRP reinforcing bars. Some of the parameters incorporated in the numerical analysis include longitudinal reinforcement ratio and compressive strength of concrete, both of which affect the flexural capacity of beams. It is shown in this study that replacement of traditional reinforcing steel reinforced bars by GFRP bars significantly decreases mid-span deflection and increases ultimate load. The strain distribution along GFRP longitudinal reinforcing bars is totally different from that of traditional steel bars.
EXPERIMENTAL STUDY OF BEAMS WITH EMBOSSED WEB
Authors: Shin Kyung-Jae , Park Han-Min , Kim Wha-Jung , Chae Il-Soo , Kim Hyung-Seok
Published: March 2020

In order to reduce the weight and the material cost in the steel structures, a study on the slender sectional design has been continuously carried out. Steel beams with corrugated web have been widely used in the steel structures. The welding part between the corrugated web and the flange, however, is not straight, which makes the production costs increased. In order to compensate for this drawback, steel beam with an intaglio and embossed web (IEB) was invented by Innovation & Smart Heavy Industry Co., Ltd., South Korea. Plain plate is pressed to keep the upper and lower boundary of the web straight. This makes it possible to weld the flange and the embossed web by the automatic welding machine. In this study, four types of specimens were tested for comparison with plain H-shaped steel beam. Experimental results showed that the maximum load of the IEB specimens is about 1.3 times larger than that of the H-shaped steel beams. This is because the tension field action of embossed web significantly increased the post-buckling strength.
ESTIMATION OF VEHICULAR COLLISION FORCE FOR BRIDGE COLUMNS USING COMPUTATIONAL MODELS
Authors: Wehbe Nadim , Boudaqa Abdullah
Published: March 2020

Although not commonly occurring, collisions of heavy vehicles with highway overpass bridge columns have happened in the past and resulted in catastrophic structural failures that paralyze traffic on both the overpass and the highway below. A study that was conducted at South Dakota State University performed risk assessment and developed mitigation strategy for vehicular collision with bridge columns on South Dakota interstate highways. Since the collision force is dependent upon the stiffness of the structure and the approach speed of the crashing truck, a finite element (FE) dynamic analysis was performed in the study to evaluate the collision forces resulting from two different truck sizes crashing into a prototype bridge bent at three different approach speeds (55 mph, 65 mph, 75 mph). This paper covers the FE simulation that was performed using computer software. The results indicate that the 600-kip vehicular collision force specified by AASHTO is a reasonable estimate for the load demand induced by an 80,000 lb. tractor-trailer crashing into a bridge column at an approach speed not exceeding 55 mph.