bluuebunny/crossref_metadata_2025 huggingface dataset:
First International Conference on Rammed Earth Construction: report
Authors: Ciancio Daniela , Beckett Christopher , Augarde Charles , Jaquin Paul
Published: July 2016

In February 2015, the University of Western Australia organised the First International Conference on Rammed Earth Construction. The event was a major success with participants from 11 countries. The participants were representatives from the research (scientists, professors, students) and industry worlds (engineers, architects, builders). The conference provided the unique opportunity to present recent advances in rammed earth research, innovative construction practices and sustainable projects in different countries. It also provided the opportunity to discuss the current issues experienced by the rammed earth industry around the world and to create collaborations between research institutions. This paper presents a summary of the discussions held at the forums of the event. It aims to disseminate the priority research topics identified at the conference and to increase awareness of the difficulties currently experienced by the rammed earth industry and by academia.
Earth construction in Algeria between tradition and modernity
Authors: Baiche Bousmaha , Osmani Mohamed , Walliman Nicholas , Ogden Raymond
Published: July 2016

In the south of Algeria, many indigenous settlements have been built using local earth construction techniques; in the north, despite the availability of suitable earth, only a few rural contemporary settlements have been built using ‘improved’ earth construction. This paper adopts a case study approach to examine and compare structural deficiencies of two earth-built housing settlements in different regions in Algeria. In the indigenous earth settlement in the south, where adobe was used in combination with local timber and stones, the dwellings exhibit many structural defects. Stabilisation of the soil and introduction of modern materials in the contemporary rammed earth settlement in the north has not, however, helped produce structurally adequate dwellings. These dwellings also exhibited many cracks and debonding of rendering, and thus did not fulfil the requirements and aspirations of their occupants. The study concludes that for a potentially successful earth building scheme there are inter-related factors that should be considered: selection of an appropriate soil and construction technique, implementation of a suitable structural design, construction and post-completion processes, availability of relevant skills and provision of adequate training on the construction technique.
Types of alkali–aggregate reactions and the products formed
Authors: Leemann Andreas , Katayama Tetsuya , Fernandes Isabel , Broekmans Maarten A. T. M.
Published: July 2016

The alkali–aggregate reaction comprises the alkali–silica reaction (ASR) and the alkali–carbonate reaction (ACR). Reaction kinetics of the ASR depends on the grain size and crystalline structure of the reactive silicon dioxide. The reaction starts in the aggregates along the particle periphery and progresses inward. After cracking of the particle, larger amounts of reaction products are formed and are eventually extruded in the cement paste, where they fill cracks and voids. ASR products within aggregates predominantly consist of (hydrated) silicon, alkalis and calcium with characteristic atomic ratios of (Na + K)/Si ∼ 0·25 and Ca/Si ∼ 0·25. They take up additional calcium while releasing alkalis when extruded. Amorphous and crystalline reaction products occur and coexist. Expansion is the result of water adsorption by the reaction products. In ACR, harmless dedolomitisation is distinguished from deleterious reaction of fine-grained silica disseminated throughout the carbonate matrix. Further research is needed to gain more in-depth knowledge about the thermodynamics and kinetics of ASR products and the mechanisms of expansion. This should allow the establishment of a better link between concrete structures and both accelerated testing and models.
Appraising structures affected by the alkali–aggregate reaction
Authors: Godart Bruno , Wood Jonathan G. M.
Published: July 2016

This paper presents the appraisal of structures affected by the alkali–aggregate reaction (AAR) and is based on the overall philosophy and principles that have already been established in a Rilem report to be published. This report is part 2 of the recommendations on diagnosis and appraisal that have been developed in the frame of the Rilem technical committee 219-ACS. It recommends that, from the start of an investigation, there should be close links between the materials science team inspecting and testing for diagnosis and the structural engineers carrying out an appraisal. This paper first describes the initial appraisal that is based on site investigations (cracking index, global deformation and environment analysis) and the laboratory investigations on the cores taken from the structure (mechanical testing, residual expansion tests) in order to obtain a severity assessment of the structure. Then it presents the structural assessment that includes the severity rating of the structural elements and the structural assessment based on a numerical modelling referring to Larive's law.
Alkali release from aggregates: contribution to ASR
Authors: Menéndez Esperanza , García-Rovés Ricardo , Ruiz Sergio
Published: July 2016

The alkali–silica reaction in concrete is normally associated with alkalis from cement. However, some aggregates have alkalis in their crystalline or amorphous phases that can be released during long-term exposure to the water in concrete structures. Previous research has demonstrated that alkaline feldspars in aggregates can supply a significant amount of alkalis when exposed to alkaline solutions. Other research indicates that micas can release alkalis and promote alkali–silicate reaction. The main problem is the evaluation of the potential contribution of the alkalis released by aggregates during the service life of a concrete structure. This paper describes accelerated tests that can determine the level of alkalis released from aggregates, but finds that the results are not representative of the long-term behaviour of concrete structures. Alternative tests are being developed, but these could take much longer, and it is concluded that numerical methods may be the most practical solution.
ICAAR 1974–2016 conferences for examination of AAR in concrete
Authors: Andiç-Çakır Özge , Poole Alan B. , Ideker Jason H.
Published: July 2016

The proceedings of a series of international conferences and their role in developing key areas of understanding and reporting the deleterious reaction between Portland cements and certain types of aggregate in concrete are discussed. Developments in the diagnosis and testing for potential reactivity are outlined. The role of these conferences in developing and reporting on international research into mechanisms, the systems of specification for avoiding reaction and the methods employed to renovate or repair concrete structures are also summarised. Specific new developments in understanding are identified in the conference proceedings. They have provided a major forum for reporting case histories from countries worldwide, the identification and diagnosis of reactions, and the results of remediation and repair of the structures involved; some of these case histories are outlined.
Options for minimising the risk of alkali–aggregate reactions
Authors: Nixon Philip , Fournier Benoit , Thomas Michael D. A.
Published: July 2016

An alkali–aggregate reaction (AAR) is one of the many deleterious processes affecting the durability of concrete infrastructure worldwide. It is the result of reactions between the alkaline pore solution in concrete and some reactive phases in the aggregate. The reactions lead to the formation of an expansive force within the concrete, which, in certain conditions, can lead to damaging expansions and cracking in the concrete. For such damaging expansion to occur, all of the following conditions must be present simultaneously: (a) a sufficiently alkaline pore solution, (b) a critical amount of reactive material and (c) a sufficient supply of water. Effective specifications to avoid damage from the above reactions are based on ensuring that at least one of the these conditions is absent. The development of the precautions against AARs around the world generally involves the determination of the necessary level of precaution required based on the aggregate's reactivity, the size of the structural element and the environment (exposure conditions), and a classification of the ‘criticality’ of the structure to build. The development and implementation of preventive actions according to the level of precaution required are then undertaken following prescriptive or performance approaches.
Expansive chemical reactions in dams and hydroelectric projects
Authors: Charlwood Robin G. , Sims Ian
Published: July 2016

The various forms of expansive reactions, including alkali–aggregate reactions and internal sulfate reactions, which may occur in the concrete in hydroelectric projects and dams are characterised. The effects of chemical expansion on different dam types and hydro-project structures and their vulnerabilities to it are identified. Preliminary estimates of strain and the timing of the development of critical issues for a sampling of known cases where data are available are presented in order to give some general indications of the magnitudes of the expansion strains that have been found to begin to cause critical operational or safety issues. The effectiveness of the current testing methods is reviewed. For dams where the expansions are continuing unabated, such as where alkali resupply is a factor, at present there is no known means to stop the reaction, and the focus is on long-term management of the expansion by slot cutting or other means to accommodate the effects. In only a very few cases has replacement become necessary due to expansive chemical reactions. Usually, the deterioration in key material properties is limited. The main concerns relate to the deformations that occur as a result of the expansion, causing cracking and/or equipment misalignment.
Influencing compressive strength of roller-compacted concrete
Authors: Chhorn Chamroeun , Lee Seung Woo
Published: July 2016

Roller-compacted concrete is a type of zero-slump concrete that usually has a higher compressive strength than ordinary concrete, with the same cement content. This is primarily due to the high level of aggregate interlock achieved by compaction, but many other factors are also involved. The goal of this study was to investigate the influence of aggregate gradation, cement content, water content, compaction effort, curing conditions and admixtures on the compressive strength of roller-compacted concrete. It was found that aggregate gradation within the limit recommended by the Portland Cement Association is desirable for high compressive strength. The concrete becomes less sensitive to water content when the cement content is augmented, and a minimum of 98% modified Proctor dry density ratio is needed to achieve the maximum strength. Moderate strength improvement can be obtained with moisture control during the curing process, and it is possible to extend working time by using admixtures without compromising strength.
Shakedown analysis of civil engineering structural elements
Authors: Panagiotou Konstantinos D. , Spiliopoulos Konstantinos V.
Published: July 2016

The determination of safety margins for civil engineering structures under varying loadings is a major issue for modern engineering design. Direct methods and particularly shakedown analysis is the only suitable tool for this issue. This paper aims to propose the recently developed direct method, that was named RSDM-S, for the shakedown analysis of civil engineering structural elements. The method is an iterative procedure, which with the aid of the decomposition of the residual stress field into Fourier series, shrinks the load domain until the residual stresses become constant in time. The method is formulated within the finite-element method and is applied to two-dimensional elasto-plastic structural elements under cyclic mechanical loadings.
AAR-based decomposition method for lower bound limit analysis
Authors: Muñoz José J. , Rabiei Nima
Published: July 2016

Despite the recent progress in optimisation techniques, finite-element stability analysis of realistic three-dimensional problems is still hampered by the size of the resulting optimisation problem. Current solvers may take a prohibitive computational time, if they give a solution at all. The possible remedies to this are the design of adaptive de-remeshing techniques, decomposition of the system of equations or of the optimisation problem. This paper concentrates on the last approach, and presents an algorithm especially suited for limit analysis. Optimisation problems in limit analysis are in general convex but non-linear. This fact renders the design of decomposition techniques specially challenging. The efficiency of general approaches such as Benders or Dantzig–Wolfe is not always satisfactory, and strongly depends on the structure of the optimisation problem. This work presents a new method that is based on rewriting the feasibility region of the global optimisation problem as the intersection of two subsets. By resorting to the averaged alternating reflections (AAR) method in order to find the distance between the sets, the optimisation problem is successfully solved in a decomposed manner. Some representative examples illustrate the application of the method and its efficiency with respect to other well-known decomposition algorithms.
Free vibration of FG Lévy plate resting on elastic foundations
Authors: Pradhan Karan K. , Chakraverty Snehashish
Published: July 2016

In this paper, free vibration of thin functionally graded (FG) Lévy plates resting on Winkler and Pasternak elastic foundations have been investigated. As a convention, Lévy plates have two opposite edges simply supported and the other two opposite edges are taken as a combination of clamped, simply supported and free edge conditions. A simple power-law form is assumed here to judge the variation of material properties of the FG constituents along the thickness direction. The numerical modelling has been performed using the displacement field of classical plate theory and Rayleigh–Ritz method to obtain the generalised eigenvalue problem. The displacement component is expressed as a linear combination of simple algebraic polynomials. The effect of different physical and geometrical parameters along with elastic foundations on the free vibration characteristics of FG Lévy plates has been investigated. New results of eigenfrequencies and their corresponding three-dimensional mode shapes are incorporated here after performing the test of convergence and validation of present results with the available literature in special cases.
Delivering safe geological disposal of nuclear waste in the UK
Authors: Tweed Cherry , Ellis Alun , Whittleston Rob
Published: July 2016

This paper discusses Radioactive Waste Management Limited's plans for implementing UK government policy for the safe geological disposal of UK's higher-activity radioactive waste. As a pioneer of nuclear technology, the UK has accumulated a diverse legacy of higher-activity radioactive waste. The paper provides a brief history of the project to date and key developments to be expected in the coming years. The paper gives an overview of the safety of geological disposal, and provides examples of the approach to ensure confidence in safety during the transport, operational and post-closure phases. It discusses the challenges in the design, construction and operation of a project with a lifetime of more than 100 years. Finally, the paper considers commonalities between the UK project and international experiences in this topic.
Design optimisation of hybrid energy systems: a case study
Authors: Bapat Rijuta S. , Mhaisalkar Vasant A. , Ralegaonkar Rahul V.
Published: July 2016

Cities in developing countries are experiencing rapid population growth that exerts excess pressure on energy and adversely affects the environment. Uninterrupted supply of energy is possible through the use of hybrid energy systems. This paper is addressed towards identifying and integrating the locally available renewable energy sources of a city in a composite climatic zone of India by using ‘hybrid optimisation model for electric renewables’ software. A solar–biodiesel generator system in conjunction with a battery bank has been considered for obtaining the system's optimum configuration at a minimum annualised cost while satisfying the energy demand. Sensitivity analysis and validation of optimum results are also presented in this paper. This research work is an attempt to encourage the use of an off-grid hybrid system with locally available renewable energy resources in the composite climate of India for reducing carbon dioxide emissions.
Analysis of ground-source heat pumps in north-of-England homes
Authors: Ali Alexis , Mohamed Mostafa , Abdel-Aal Mohamad , Schellart Alma , Tait Simon
Published: July 2016

The performance of ground-source heat pumps (GSHPs) for domestic use is an increasing area of study in the UK. This paper examines the thermal performance of three bespoke shallow horizontal GSHPs installed in newly built residential houses in northern England as compared with a control house fitted with a standard gas boiler. A 350 m high-density polyethylene pipe with an external diameter of 40 mm was used for each house as a heat pump loop. The study investigated the performance of a single-loop horizontal ground heat exchanger against a double loop. It also investigated rainfall effects on heat extraction by comparing a system with an infiltration trench connected to roof drainage against a system without an infiltration trench above the ground loops. Parameters were monitored for a full year from October 2013 to September 2014. Using the double-loop exchanger has shown an enhanced performance of up to 20% compared with a single loop. The infiltration trench is found to improve performance of the heat pumps; the double loop with an infiltration trench had a coefficient of performance 5% higher than a double loop without a trench.
Briefing: Information security in community energy
Authors: Kent Jeremy , Rowe Jennifer , Tomlinson Clive
Published: July 2016

There are many community energy schemes. Their number and variety are increasing briskly. They bring new kinds of information into existence and they handle existing kinds of information in new ways. They share, to varying degrees, vulnerabilities to a wide range of information security threats. Those threats include new opportunities for crime and terrorism. At the extreme, their effects include danger to persons through interference with their ‘critical home infrastructure’ such as heating, lighting and refrigeration. The excitement of the novelty of community energy, and the focus of thinking on flows of energy and of money, means that often the flows of information, and their security, are not being considered as carefully as they ought to be.
Algal biorefinery for sustainable development and the challenges
Authors: Zhu Lian-Dong , Huo Shuhao , Shakeel Shah Rukh , Li Zhaohua
Published: July 2016

Microalgae are a promising biofuel feedstock, since they can mitigate carbon dioxide through photosynthesis and may not compete with food production for farmland. A lot of research has been done in microalgal biology, culture, harvest, biofuel conversion and so forth. However, both academia and industry suggest that microalgae-based biofuel production is still in its infancy due to a lack of economic efficiency. Microalgae contain lipids, carbohydrates (starch and cellulose), proteins and a wide range of inorganic and organic molecules. These components can be converted into biofuels, feed, food and other high-value products such as cosmetics, fine chemicals and pharmaceuticals. Through microalgal biorefinery, multiple products (low-volume high-value bio-products and low-value high-volume biofuels) can be produced, thus maximising the value derived from microalgal biomass. However, some uncertainties with risks also exist during the process, and should be forecast well in advance and then minimised or even eliminated. The main challenges during microalgal biorefinery include water footprint, energy balance, production costs, market potential and policy influence. In an effort to mitigate these uncertainties, further research and development in the field is still required.
Failures of US bridge rocker bearings
Authors: Cohen Julie Mark , Wetzk Volker
Published: July 2016

Bridge bearings made of iron or steel, first used in early railroad bridges about 150 years ago, are relatively small structural components that support the loads of bridge superstructures. Fixed bearings directly transfer forces from a bridges superstructure to its substructure. Movable bearings, such as sliding bearing plates, rollers and rockers, accommodate the thermal expansion of the superstructure without transferring it to the substructure. Rocker bearings tilt to accommodate thermal movement, theoretically without imposing stresses on the substructure. This paper concerns rocker bearings which are non-redundant components and have two states: stable and toppled over. When these bearings topple over, no alternate load paths exist, which results in a failed superstructure. As such, rocker bearings are critical bridge components. An overview is given of the history of use and failures of rocker bearings from nineteenth-century railroad bridges to US highway bridges with tall and slender rocker bearings that date from the late 1950s.
The Iron Bridge: desk study and engineering assessment
Authors: Miller James
Published: July 2016

The Iron Bridge in Shropshire was a pioneering structure. Constructed in 1779, it was the first iron bridge in the world. Its unique semi-circular shape creates an elegance when reflected in the river, yet it is essentially the wrong form for a cast-iron engineering structure, being highly redundant and unable to accommodate the significant movement that has occurred in the Severn Gorge at this location. This has led to the many crack defects that now exist in the ironwork. This paper outlines the work undertaken for custodian English Heritage in both researching the history of defects in the bridge and modelling and assessing the present-day structure. It looks at the long history of repairs on the structure. It describes in summary the extensive process of surface and solid modelling and advanced analysis undertaken to assess the current capacity. It concludes that, although many predate modern conservation practice, the bridge repairs have essentially followed good conservation principles and that sufficient capacity exists to assure continued public enjoyment of the bridge.
Seismic reinforcement of historical steel bridges in Japan
Authors: Isohata Hiroshi , Kurebayashi Akio , Mori Atsushi
Published: July 2016

Both the Kiyosu and Eitai Bridges, registered as important cultural properties in 2007, are located in the lower reaches of the Sumida River in Tokyo. They were rebuilt in the latter half of the 1920s after the great Kanto earthquake of 1923 in the Japanese capital. By examining their anti-earthquake performance under the revised new standards based on the information obtained from the magnitude M7.3 great Hanshin Awaji earthquake of 1995, it was discovered that strengthening was required for both bridges. Strengthening design was considered and discussed from 2012 to 2014. It was concluded that with respect to the Kiyosu Bridge, the installation of dampers on both girder ends was required. With respect to the Eitai Bridge, the bearings on both piers were immobilised by placing additional horizontal bearings. Also, the addition of stiffeners to the arch ribs was deemed necessary to increase rigidity. The strengthening work was carried out from 2014 to 2015. This experience is expected to supply useful information for strengthening and repair/design work of historical bridges.
Deterioration assessment of an immersed-tube road tunnel in Taiwan
Authors: Chou Yung-Chuan
Published: July 2016

Taiwan has been constructing tunnels since the 1960s and more than 300 are now in operation. Unfortunately, some of the early tunnels are now showing signs of significant deterioration. This paper provides a case study of a busy 30-year-old urban undersea immersed-tube road tunnel, which is suffering from cracks, water ingress and corrosion. Non-destructive inspection techniques were carried out to determine the level of deterioration and to make an overall assessment of the tunnel’s operational safety. The paper describes the tunnel’s main defects, the results of settlement, and the structural inspections and monitoring judgements made. The paper is intended to serve as a reference for assessing the deterioration of immersed-tube tunnels.
Briefing: Activities by IABSE WG8 (Forensic Structural Engineering)
Authors: Terwel Karel , Palmisano Fabrizio
Published: July 2016

A working group on forensic engineering (WG8) was established within the International Association for Bridge and Structural Engineering (IABSE) in 2011. This working group aims to mitigate structural failures and improve forensic engineering practices. To accomplish this goal, several activities were organised such as an international survey among 48 countries to compare forensic engineering practices. Furthermore, several interesting forensic engineering sessions were organised at IABSE conferences with various presentations. Moreover, a pre-conference short course focusing on various types of failures and the process of forensic investigation was well received. It appears that there is great interest in forensic structural engineering both from practitioners and from researchers. This briefing article describes the activities of WG8 in detail.
Briefing: Reflections on the role of the expert witness
Authors: Clancy Brian
Published: July 2016

This paper tries to record some of the experiences of a civil and structural engineer and building surveyor over a period of some 50 years and how he became involved, by chance, in advising protagonists who had resorted to legal disputations to resolve their differences. The author is not a great supporter of disputations that rely too heavily on legal management of the arguments – and certainly not of going to court (if it can be avoided). He believes that going to court is, in principle, a failure, unless the matter is extremely complex or an issue upon which crucial legal clarification is required. Most other instances are, in his view, exercises in ‘bullying’, inefficiency, dishonesty, arrogance or stupidity. It is important to appreciate that most well-conducted dispute ‘cases’ (the vast majority) are resolved without ever getting to court, so the ‘expert’ aspect is required far more often than the ‘witness’ part. Most expert witness roles in building and engineering disputes are in civil law cases, but some do occasionally arise in criminal cases, particularly where injury or fatality is involved. For the sake of gathering all blame to the author himself, he confirms that the opinions that he expresses below are his and his alone and not those of the Institution of Civil Engineers.
Rapid structural assessment of garment factories in Bangladesh
Authors: Hodgson Robert L. P. , Khan Iftekhar A. , Haynes Ruth , Arnold John
Published: July 2016

Bangladesh is the world’s second biggest exporter of garments, producing a range of clothes for all the major designer labels. The collapse of the Rana Plaza building in Savar in April 2013 highlights the lack of building control that had accompanied the very rapid growth of this industry since the early 1990s and initiated a widespread assessment of the structural integrity of hundreds of similar buildings. Medway Consultancy Services (UK) Ltd undertook assessments of some 200 factories between May 2013 and December 2015 for two major buying groups. Each factory building was inspected visually to confirm that it had been built according to available plans and that the resulting structure was fit for purpose. Additional investigations, including ground investigations and exposure of footings, were undertaken in a small number of cases. This paper describes the process for prioritising assessments and the systematic approach adopted for rapid categorisation of structures. It discusses the outcomes and challenges faced when working in developing countries, particularly within a politically sensitive environment generated by global media attention.
Geotechnical case studies: emphasis on collapsible soil cases
Authors: Vandanapu Ramesh , Omer Joshua R. , Attom Mousa F.
Published: July 2016

Direct exposure of soil to certain atmospheric agents, such as water, can influence adversely or favourably the engineering behaviour of the soil. For instance, saturated and unsaturated/partially saturated soils behave differently, so do soils under seepage and hydrostatic pressures. Many theories in soil mechanics idealise soils as either cohesive or non-cohesive, and this has allowed much research to be done on saturated cohesive soils. However, non-cohesive soils have not received as much attention, apart from recent strength and dilatancy theories, yet in some parts of the world, certain non-cohesive soils pose significant risk to structures built on them. The most problematic examples of such soils are collapsible soils that may not be detected and properly considered in routine ground investigation activities. In this paper some case studies of collapsible soils in the United Arab Emirates are examined to analyse the effect of their collapse on infrastructure and the possible techniques to ameliorate the situation. The case studies include various sites that were found to suffer structural damage traceable to collapsible soils. It is found that in most cases the soil collapse was due to infiltration of rainwater or water from sustained irrigation activities at the surface.
Knowledge Management Strategy and Organizational Change in Commercial Banks in Kenya
Authors: Maalu Jackson , MwachinaloDosho Said
Published: July 2016

This study attempts to establish the relationship between knowledge management strategy and organizational change in commercial banks in Kenya. Knowledge management strategy can assist a firm to induce individuals to offer their knowledge voluntarily for a firm’s use, achieve distinctive advantage through full exploitation of a firm’s knowledge base, build institutional memory and protect it from prying competitors. It can influence amongst others a successful organizational change. The study employed a descriptive cross sectional survey. A total of 39 commercial banks in operation (not under statutory management) were surveyed. Primary data was collected from the respondents using a questionnaire.Analysis utilized largely the median and mode as measures of central tendency while the inter-quartile range was used as a measure of dispersion. Percentages and frequencies were also utilised to present part of the findings. Pseudo R square statistics were used as a measure of association between knowledge management strategy (independent variable) and organizational change (dependent variable). The study found that commercial banks in Kenya primarily employ proactive and moderate knowledge management strategies. Both strategies had a strong association with the organizational changes that the commercial banks have undergone. The most popular form of organizational change was found to be a mix of both revolutionary and evolutionary change. The findings of this study are consistent with theory in that knowledge management strategy was found to have given banks dynamic capabilities in pursuit of a firm’s goals such as organizational change.
Produção de livros didáticos no mestrado profissional de História: relato de experiência a partir de uma disciplina da UFRB
Authors: Almeida Leandro Antonio
Published: July 2016

Este trabalho reflete sobre a produção de materiais didáticos no Mestrado Profissional de História. Apresentaremos essa modalidade de pós-graduação stricto sensu que se expandiu na área de História nos últimos anos e, depois, trataremos dos desafios do tema mediante uma experiência de produção em uma disciplina intitulada “Metodologia da Pesquisa e da Produção de Materiais Didáticos”. Nela solicitava-se aos mestrandos material didático, acompanhado de um guia para o professor, em qualquer formato e suporte, sobre um dos temas de pesquisa do programa. A maioria dos alunos optou por trabalhar com livros paradidáticos, apresentados em formato digital (PDF). Durante a escolha e produção foram utilizados saberes acadêmicos, pedagógicos e práticos, mobilizados conforme o contexto dos alunos e os objetivos formativos. Os relatórios dos mestrandos mostraram a pouca familiaridade com a linguagem voltada aos alunos da educação básica e com os saberes de edição e diagramação dos livros. Por fim, a produção de materiais didáticos de maneira interdisciplinar é um desafio para os mestrandos.
Epistemologia e Ensino da História
Authors: Alves Luis Alberto
Published: July 2016

A articulação entre investigação e produção científica na área da História e os programas escolares ocupa os debates internacionais. A importância concedida pelos decisores educativos às ciências da educação reforçaram a transversalidade dos saberes em detrimento das especificidades epistemológicas. A divisão tradicional entre saber e saber-fazer sai fragilizada, e a luta pela inscrição de uma didática ancorada no saber disciplinar percorre um caminho nem sempre facilitado. A maturidade hoje assumida pela Educação Histórica leva-nos de regresso à epistemologia do saber histórico, assumida como a melhor estratégia para levar o aluno a aprender segundo regras específicas da construção desse saber, transformando-o, pelo conhecimento adquirido, num verdadeiro utilizador do passado para uma efetiva intervenção cívica no presente. A prática de formação de professores de História em Portugal ao longo de 30 anos nos permite enfatizar a importância do regresso a fontes primárias e a processos didáticos socioconstrutivistas para reafirmar o sentido do ofício do historiador e das suas práticas científicas no contexto escolar da disciplina.
Jovens brasileiros, consciência histórica e vida prática
Authors: Schmidt Maria Auxiliadora
Published: July 2016

O trabalho tem como objetivo analisar a relação entre a formação da consciência histórica e a vida prática de jovens, a partir da interpretação dos significados que determinados acontecimentos, como as manifestações de rua, têm nesse processo, particularmente quando estas manifestações têm como horizonte reivindicações de direitos básicos relacionados à vida prática dos sujeitos. Optou-se pela metodologia da pesquisa de cunho qualitativo, recortada a partir do estudo de um caso específico de um grupo de jovens estudantes de Curitiba. Resultados permitem afirmar que conhecer elementos da consciência histórica dos jovens, bem como fazer uma avaliação preliminar de formas de atuação de sua consciência histórica em relação às demandas da vida prática, pode ser um dos pressupostos metodológicos para o ensino de história.
Os Centros Históricos como laboratórios de Educação Histórica e Patrimonial
Authors: Pinto Helena
Published: July 2016

O desenvolvimento, de forma sistemática e segundo critérios metodológicos, de atividades educativas relacionadas com património carece de discussão sobre práticas consistentes de Educação Patrimonial em articulação com reflexão sobre pesquisa existente em Educação Histórica. A par da sensibilização para a salvaguarda do património, os professores podem realizar práticas promovendo a interpretação de fontes diversas – nomeadamente objetos em contexto de centros históricos – encorajando os alunos a questioná-las de forma crítica e progressivamente mais complexa. Apresenta-se um estudo de natureza qualitativa, que investigou como alunos portugueses (de 7º e 10º ano) inferem a partir de objetos/edifícios durante um percurso no centro histórico de Guimarães, Portugal, em atividade educativa, com seus professores de História. A análise de dados sugeriu diversos perfis conceptuais quanto ao modo como os alunos dão sentido ao património, e como eles e seus professores entendem a relação dialógica entre passado, presente e futuro, que caracteriza a consciência histórica.
Linguagens de Clio: práticas pedagógicas entre a literatura e os quadrinhos no ensino de História
Authors: Fontineles Filho Pedro Pio
Published: July 2016

O presente estudo investiga o Ensino de História por meio das interconexões entre História e narrativas ficcionais, com ênfase na literatura e em histórias em quadrinhos. Como delimitação do objeto, as reflexões partiram das observações e debates nas disciplinas de Práticas Pedagógicas, especialmente aquelas que dão espaço para discussões sobre tal relação e que compõem o currículo do Curso de Licenciatura Plena em História da Universidade Estadual do Piauí. O recorte temporal da pesquisa inicia-se em 2006, quando tais disciplinas foram efetivamente implantadas no currículo do curso. Os aportes teóricos seguiram os lastros de Cerri (2013), Compagnon (2012), Vergueiro (2007), Guimarães (2011), Vilela (2007) e Chartier (2002). Considerou-se que a prática pedagógica potencializa a ampliação dos horizontes teóricos, metodológicos e didáticos, no que tange às aproximações entre História e demais linguagens e narrativas.
Formación docente inicial y cultura digital
Authors: Ertola Fabiana , Parra Erwin
Published: July 2016

El trabajo que desarrollamos en el marco de la Universidad Nacional del Comahue en la Norpatagonia nos sitúa como formadores de formadores además de investigadores. En este artículo nos interesa compartir algunos datos sistematizados y prácticas de enseñanza en el nivel medio, accionadas y reflexionadas dentro de la formación docente inicial del profesorado en historia. Son experiencias que recuperamos para pensar en el marco de la cultura digital, el uso de tecnologías y los desafíos de su utilización en la construcción de propuestas para la enseñanza de la historia y/o educación ciudadana en contextos particulares. A partir de ellas se aventuran opciones, alertas, límites y posibilidades para posicionarse entre convicciones e indeterminaciones, entre los viejos y nuevos problemas que el siglo XXI nos trae aparejado.
As políticas públicas de avaliação do livro didático: múltiplas experiências
Authors: Maia Tatyana Amaral
Published: July 2016

Resenha do livro: Oliveira, Margarida Maria Dias; Costa, Aryana (Org.) Para que(m) se avalia? Livros Didáticos e Avaliações (Brasil, Chile, Espanha, Japão, México e Portugal) Natal: Ed. UFRN, 2014. 164p.
Interview – Jörn Rüsen Some ideas on the intersection of metahistory and history didactics
Authors: Gago Marília
Published: July 2016

Interview conducted by email on March 1, 2, and 28, 2016. Jörn Rüsen, Senior Fellow at the Kulturwissenschaftliches Institut (Institute for Advanced Study in the Humanities) at Essen, Germany, and Honorary doctorate of Universidade de Brasília (Brazil) and University of Lund (Sweden). Professor emeritus at the University of Witten/Herdecke (Germany) and Order of Merit, State of Northrhine-Westfalia, Federal Republic of Germany. He was Visiting Chair Research Fellow at the Institute for Advanced Studies in Humanities and Social Sciences National Taiwan University, head of the research project on “Humanism in the era of globalization – an intercultural dialogue on humanity, culture, and values” at the Kulturwissenschaftliches Institut at Essen, Germany, and President/director of that Institute.
Física y contaminación atmosférica
Authors: Riveros Héctor G.
Published: July 2016

La Enseñanza dela Físicasirve para enseñar a razonar, los temas estudiados sirven como motivación. El aprender a razonar sirve en prácticamente todas las actividades de los seres humanos.La Físicatiene muchas aplicaciones en la lucha contra la contaminación atmosférica. En particular, estudiaremos la propuesta de la aplicación del Programa Hoy no Circula para reducir la contaminación atmosférica enla Zona Metropolitanadel Valle de México. La conclusión es que mejora la circulación, pero no reduce las concentraciones medidas de los principales contaminantes.
Efecto de la atorvastatina en el tratamiento de la periodontitis crónica moderada
Authors: Rocha Navarro Miriam , Fajardo Martha , Sánchez-Marín Francisco , Espinosa Emanuel
Published: July 2016

Introducción: Las estatinas son inhibidores de la hidroximetil-glutaril Coenzima A reductasa que han sido empleadas para el tratamiento de la hipercolesterolemia. Se ha reportado que tienen efectos favorables sobre el metabolismo óseo disminuyendo el riesgo de fracturas y en algunos estudios un aumento de la densidad mineral ósea. Por lo anterior, el objetivo de este estudio   fue  comparar   el  tratamiento  periodontal  más  atorvastatina (ATV) sobre  los  parámetros periodontales y hueso alveolar versus tratamiento periodontal más placebo en pacientes con periodontitis crónica moderada (PCM).Materiales y Métodos: Estudio controlado, doble ciego, aleatorizado, en el que participaron 38 pacientes con PCM de 35 a 65 años, a los cuales se les administró por tres meses un tratamiento con ATV (20 mg/día, n=19) o complejo B (grupo control n=19). Todos los pacientes recibieron el mismo tratamiento periodontal al inicio del estudio. Se tomaron muestras de sangre en ayuno para cuantificar glucosa, perfil de lípidos, fosfatasa alcalina, N-telopéptidos y 17b-estradiol. Se evaluaron los siguientes parámetros periodontales: Profundidad de las bolsas periodontales, sangrado gingival, recesión gingival, pérdida de inserción, movilidad dental, y placa dentobacteriana, además de la distancia de la cresta ósea alveolar a la unión cemento esmalte (COA–UCE). Todas las mediciones se realizaron al inicio y al final del estudio. Para el análisis de los datos se utilizó la prueba t para muestras dependientes y su alternativa no paramétrica para observar diferencias entre los dos grupos. La corrección de Bonferroni para comparaciones múltiples fue calculada en base a los valores de P. Para observar diferencias entre los grupos por género y estado menopáusico se utilizó la prueba t para muestras independientes o su alternativa no paramétrica U de Mann-Whitney. Se consideró una p< 0.05 como significativa. Resultados: Los parámetros periodontales mejoraron en ambos grupos. No obstante, el grupo ATV mostró una disminución significativa en la movilidad dental (Δ =  -0.17 ± 0.11 % vs.  Δ =  -0.06 ± 0.11 %, p<0.005). La distancia COA-UCE diminuyó significativamente en el grupo tratado con ATV cuando se le comparó con el grupo control (Δ =  -0.75 ±0.7 mm vs. Δ =  -0.09 ±0.4 mm, p< 0.0003). Como se esperaba, en el grupo ATV diminuyó significativamente el colesterol y LDL (p<.00002 y p<.0002, respectivamente), así como los triglicéridos y VLDL con una p<.05, en ambos. Conclusión: Estos hallazgos indican quela ATV causa un significativo mejoramiento en la movilidad dental y en la altura del hueso alveolar, lo cual sugiere un efecto benéfico de las estatinas sobre el tratamiento dela PCM. La ATV fue bien tolerada por tres meses.
Propiedades electrónicas de semiconductores III-V sometidos a tensión uniaxial en la dirección [111]; un enfoque según el método tight-binding: I. Arseniuros y Fosfuro de Galio
Authors: Mora-Ramos Miguel E. , Martín Mozo J. Juan
Published: July 2016

Empleando un esquema de cálculo tight-binding que usa una base de orbitales sp3s*d5,  se estudian propiedades de la estructura electrónica de un grupo de materiales semiconductores III-V los cuales son de notable interés para la tecnología de dispositivos electrónicos y optoelectrónicos.  En específico, se analiza la influencia sobre estas propiedades de una tensión aplicada según la dirección cristalográfica [111],  haciendo uso de una formulación basada en la teoría de la elasticidad para establecer las posiciones relativas de los iones vecinos más próximos. Especial atención se presta a la inclusión del efecto de deformación interna de la red cristalina. Para cada material de los estudiados presentamos las dependencias de las brechas energéticas asociadas a los puntos Γ, X y L de la zona de Brillouin como funciones de la tensión uniaxial en AlAs, GaAs, InAs y GaP.  Asimismo, reportamos expresiones de ajuste para los valores de las masas efectivas de conducción en esos cuatro materiales. La comparación de la variación de la brecha de energía en X para el GaP, calculada con nuestro modelo, y recientes resultados experimentales para la transición indirecta entre la banda de huecos pesados y la banda X de conducción arroja una muy buena concordancia.
Saliencias Espaciales en Motores de Inducción con Rotor Jaula de Ardilla
Authors: Zamarrón Ramírez Antonio , Rodríguez Carrera Salomón
Published: July 2016

En este trabajo se presentan algunas de las saliencias espaciales que aparecen habitualmente en los motores de inducción estándar con rotor jaula de ardilla. Para medir y determinar la magnitud relativa de las saliencias espaciales que se acoplan a los devanados del motor de inducción se utiliza la técnica de inyectar una señal portadora de alta frecuencia en el motor. Se muestra además la forma de crear una saliencia dependiente de la posición del rotor la cual puede ser utilizada en accionadores de c.a. para estimar la velocidad y/o posición del rotor en muy baja velocidad sin utilizar el sensor de velocidad o posición.