bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanical Properties of Build-Up Layers on Failed Ceramic Roller
Authors: Mašlejová Alicia , Drotár Atila , Černík Martin , Zubko Pavol
Published: November 2018

The paper describes degradation process of ceramic rollers. Rollers behavior under mechanical and thermal load was evaluated using available methods like XRD, instrumented hardness measurement and compressive strength. The influence of residual stresses was also discussed. The first phase during the degradation crystalize from amorphous silica tridymite, cristobalite and quartz, then due to the contact and pressure of the steel strip to the surface roller iron diffuses and forms fayalite. Measured values of compression strength of roller of 55-61 MPa agree with producer documentation declared minimal values. Hardness and Young´s modulus of buildup phases identified from surface into depth were determined. Wüstite was present up to 100 mm, with hardness 6±1 GPa, Young´s modulus 75±6 GPa, fayalite, cristobalite, up to 500 mm, with hardness 5.4±0.6 GPa, Young´s modulus 51±2 GPa, tridymite over 500 mm, with the hardness 7±4 GPa and Young´s modulus 58±25 GPa.
FEM of Cracking during Nanoindentation and Scratch Testing in the Hard W-C Coating/Steel Substrate System
Authors: Lofaj Frantisek , Németh Dušan
Published: November 2018

Finite element modelling (FEM) and eXtended FEM (XFEM) combined with the experimental nanoindentation and scratch tests have been used to simulate the process of cohesive cracking in W-C coating on softer and more ductile steel substrate during nanoindentation and scratch testing. The formation of single and multiple circular “frame” cohesive cracks in the sink-in zone during nanoindentation were explained by the development of high local tensile stresses in the coatings controlled by the plastic deformation of the substrate. Analogous mechanisms were successfully applied to the simulation of multiple Chevron type cracking during scratch testing. Thus, the ability of XFEM to predict the formation of different types of cohesive cracks was confirmed. It was also demonstrated that both nanoindentation and scratch tests in combination with XFEM can be used as the methods to determine the strength and fracture toughness of thin coatings.
Degradation of HVOF Sprayed Hastelloy C-276 Local Mechanical Properties after Exposure to High Temperature Corrosion
Authors: Česánek Zdeněk , Schubert Jan , Bláhová Olga
Published: November 2018

Hastelloy C-276 coating was deposited on stainless steel 1.4923 using HP/HVOF (High Pressure / High Velocity Oxygen Fuel) thermal spraying technology to increase high corrosion resistance. Possible influence of high temperature corrosion on local mechanical properties change of Hastelloy C-276 was also evaluated in this article. High temperature corrosion is corrosion in the molten salts environment. The salt mixture of 59 % Na2SO4 with 34.5 % KCl and 6.5 % NaCl was used in this study. The selected exposure temperatures were 525 °C and 575 °C and the tests for both temperatures were conducted in autoclave for the time interval of 168 h. The coating and salt mixture layer was analyzed using scanning electron microscope (SEM), EDS analysis and nanoindentor (MTS Nanoindenter XP). High temperature resistance of Hastelloy C-276 coating was evaluated based on the changes in coating surface and according to the occurrence of various phases created on the coating surface during this test. It can be assumed that Hastelloy C-276 coating deposited by HVOF technology shows selective oxidation under the salt film.
Multi-Parameter Fracture Mechanics: Crack Approaching a Bi-Material Interface
Authors: Malíková Lucie , Klusák Jan
Published: November 2018

Fracture behaviour of a crack approaching a bi-material interface is investigated. A three-point bending configuration of a cracked specimen is simulated numerically by means of the finite element method and the interaction between the crack and aggregate is studied. The crack deflection angle is estimated by means of the maximum tangential stress criterion in its classical as well as generalized (multi-parameter) form considering the Williams’ power series with various numbers of the higher-order terms for the tangential stress approximation. The influence of the elastic mismatch and of other parameters on the calculated initial crack propagation angle is discussed.
Evaluation of the Influence of the Facies Genesis of the Reservoir Unit of the Fainsk Oil Field YUS1 Facility on the Effectiveness of Integrated Processing of the Injection Wells Bottomhole Formation Zone with the Application of Acid Compositions
Authors: Aleksandrov Vadim , Kadyrov Marsel , Ponomarev Andrey , Drugov Denis , Neelova Evgeniya
Published: November 2018

One of the main problems with the bottomhole formation zone processing is the choice of an acid composition adapted to the peculiarities of the geological structure of the facility. The highest technological effect of the geological and technical interventions using physicochemical formation stimulation techniques is achieved when the genesis of processed deposits is taken into account during the process of treatment planning. The research objective is to assess the impact of the reservoir units formation (genesis) characteristics on the effectiveness of integrated processing of the bottomhole formation zone of injection wells with the application of acid compositions. Using the geological and routine analysis of the development process parameters for deposits located in various facies zones, the operational benefits of the bottomhole formation zone integrated treatments in injection wells were evaluated and practical recommendations were provided.
Efficiency Analysis of Processing Injection Wells with Acid Compositions
Authors: Aleksandrov Vadim , Kadyrov Marsel , Ponomarev Andrey , Golozubenko Vadim , Aleksandrov Sergey
Published: November 2018

Efficient development of oil reservoirs includes measures to restore and enhance the porosity and permeability properties of reservoir units that are gradually impaired during well operation. As a rule, various technologies of bottom-hole formation zone processing (BZP) of wells are used for these purposes. Special requirements to BZP technologies are applied during interventions in low-permeability reservoirs where the geological structure of reservoir units has the highest impact on the efficiency of works. In this relation, it seems interesting to study the specifics of geological structure of reservoir units in a laboratory for the efficiency of interventions using physical and chemical methods of reservoir stimulation. The research objective is to assess the efficiency of processing reservoir units with acid compositions of various concentration and type. Using laboratory experiments, physical and chemical parameters were quantitatively assessed that characterize the speed and depth of interaction between acid compositions and reservoir units.
Some Anionic Surfactants as Corrosion Inhibitors for Carbon Steel in Hydrochloric Acid Solution
Authors: Assem Rania , Fouda A.S. , Ibrahim A.A. , Saadawy M.
Published: November 2018

The corrosion inhibition effect of some anionic surfactants (Diisononyl phthalate (A), N-oleyl-1, 3-propane –diamine (B), and Sodium lauryl sulphate (C)) on the corrosion of carbon steel in 1M hydrochloric acid solution were studied by chemical method (weight loss) and electrochemical methods (potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). From the results, it was clear that these surfactants are good inhibitors for corrosion of carbon steel in 1M HCl solution. Their inhibition depends mainly on their concentrations and temperature of solution. Polarization data revealed that these surfactants act as mixed type inhibitors. The surfactants adsorptions were found to follow Langmuir’s adsorption isotherm. The thermodynamic parameters of activation and adsorption were calculated and discussed. Adsorption of used surfactants led to a reduction in the double layer capacitance (Cdl) and an increase in the charge transfer resistance (Rct). All measurements used confirmed the adsorption of the surfactants used on carbon steel surface. Confirmation of these various independent techniques proved validity of the obtained data.
Empirical Model for Dry Sliding Wear Behaviour of Centrifugally Cast Functionally Graded Al/SiCp Composite
Authors: El-Galy Islam M. , Bassiouny Bassiouny I. , Ahmed Mahmoud H.
Published: November 2018

Horizontal centrifugal casting machine was adopted to fabricate tubes of functionally graded materials (FGM) made of commercially pure aluminum reinforced with different weight fractions of SiC particles. Tubes with 2.5, 5 and 10%wt. SiCp were produced in the speed range 800 to 1100 rpm. Wear experiments involving dry sliding under different loading conditions were conducted on samples taken from three consecutive layers across the wall of the FGM tubes. Analysis of variance (ANOVA) was used to determine the significant FGM production parameters and wear test parameters (normal load and test duration) affecting the wear resistance of the samples. Obtained wear test results have been used to build a regression model to predict the expected weight loss across the wall thickness of the tube depending on the production parameters and the loading conditions.
Failure Analysis of Condensate Pump Shaft in Power Plant
Authors: Ghanem Mohamed Mosalam
Published: November 2018

Failure analysis of condensate pump shaft used in power generation plant was investigated. After 5 years of operation, the pump shaft fabricated from free-machining 416 martensitic stainless steel was suddenly ruptured into two parts. Detailed study was carried out using VT, PT together with microstructure investigation using optical and scanning electron microscope (SEM), fractography, chemical analysis and hardness testing to find out the cause of shaft failure. Failure analysis investigation revealed that the shaft was failed by torsion fatigue. Rupture was initiated from the sharp edge of the shaft outer surface at which sulphide inclusions were existed The failure is attributed to simultaneous action of both stress concentration resulted from sharp corner (design fault) and sulphide inclusions that segregate in 416 free-machining martensitic stainless steel base alloy near shaft surface (metallurgical fault). To overcome the shaft failure, sharp corner must be smooth turned and eliminate sulphide segregation by appropriate heat treatment.
Design Process of Durable and Lightweight Rally Car Frame from Ultra-High Strength Stainless Steel
Authors: Iso-Junno Terho , Niemi Henri , Mäkikangas Jarmo , Mäntyjärvi Kari
Published: November 2018

To get all outstanding mechanical properties from ultra-high strength steel (UHSS) transformed into a lightweight and durable product, a comprehensive design process must be performed. The general DFMA method has been extended to get good design solutions with limited designer resources and within a relative short time period. Key steps of the extended DFMA design process are innovative brainstorming, the agile utilization of the optimization software, the heavy use of finite element analysis and fast design iteration. In this paper, the modified DFMA design method is described step by step. This method has been successfully used in the design process of the small lightweight rally car frame. The design process of the rally car is introduced as a case example of implementation of the extended DFMA.
Effect of Chemistry Modification, Hot Forging and Partitioning on Low Alloy Grade Tool Steel
Authors: Farahat Ahmed Ismail Zaky , El-Fawkhry Mohamed Kamal , Fathy Ayman M. , Mattar Taha
Published: November 2018

Development of S6 tool steel has been discussed in this research by conducting a bit modification in the chemical composition using aluminum instead of molybdenum, and micro addition of boron to enhance the marteniste structure. Then, the hardenability and thermal stability have been detected in regarding to S6 tool steel. A novel isothermal treatment process has been suggested to enrich the retained austenite, and thereby, it has been tracked by using XRD, optical microscope, and SEM in conjugation with EDS. The effect of retained on the mechanical properties has been determined. The results ensure that aluminum has inhibited the graphite formation through the slow cooling regime. No change of hardenability or thermal stability of S6 tool steel triggered from adding of aluminum and microaddition of boron. In addition, the novel isothermal process leads to enrichment of retained austenite that has significantly affected on the combination of ductility with strength of the newly designed steel.
The Influence of Shielding Gas on Strength of the Laser Welded Thin Sheet Lap Welds
Authors: Keskitalo Markku , Mustakangas Aappo , Hietala Mikko , Mäntyjärvi Kari
Published: November 2018

The laser welding is usable method for joining thin plates with low energy input and precise penetration control. When joining of very thin sheets such as 0.5 mm the shape of the weld must be complete in order to achieve a good strength of the joint. The part of the test welds were welded without shielding gas and other part of the test welds by using 65 mm shielding gas nozzle behind the key hole. The strength of the laser weld of 0.5 mm Austenitic stainless steel (ASS) plate was measured in welds without shielding gas and Ar shielded weld. The strength of the shielded weld joints was significantly better than the joint weld without shielding gas due to convex shielded welds. In addition the shielded welds were bright which improves the corrosion properties of the joint.
First-Principle Study of Effect of Strain on the Band Structure of Germanane Monolayer
Authors: Liu Lei , Ji Yan Ju , Liu Yi Fan
Published: November 2018

The effect of strain on the band structure of the GeH monolayer has been investigated by first-principles calculations based on density functional theory. The results show that the change of the band gap under the zigzag strain, the armchair strain and the biaxial strain is nonlinear. The effect of the biaxial strain on the band gap is the most obvious. In addition, the changes of energy under the three kinds of strain are asymmetric and the biaxial strain make the energy change the most. This work has significant implication of strain to tune optical catalytic properties of GeH monolayer.
Features of Formation of Structure and Physical and Mechanical Properties of Permanent Welded Joints of Low-Alloy Steels by Methods of Adaptive Pulse Control of Energy Parameters of Welding Mode
Authors: Saraev Y.N. , Gladkovsky S.V. , Lunev A.G. , Perovskaya M.V. , Semenchuk V.M.
Published: November 2018

The features of the formation of the structure and physical and mechanical properties of all-in-one compounds of low-alloy steels are studied. It is shown that the quality and strength properties of permanent joints depend on the energy parameters of the technological process of their manufacture. The technological process is accompanied by melting, transfer and crystallization of the weld metal from the melt, which has a dominant effect on the structure, indicators of static and dynamic strength of welded joints. The ranges of welding modes that have the greatest impact on the structural and mechanical properties of the zone of permanent joints in the temperature range from +20 degrees to minus 60 degrees Celsius. The results of the research can be widely used in the practice of repair and installation works of structures of the Northern design, working in conditions of naturally low climatic temperatures.
Design of the Gating System for Production of Casting Blanks for Space Device Cases
Authors: Dmitriev Victor S. , Kostyuchenko Tamara G.
Published: November 2018

Selection of an appropriate gating system for a consumable pattern is a long and time-consuming process that requires considerable effort. Advanced design technologies can be used to design the gating system and to simulate the casting process based on the design. Simulation and design of the gating system allow detection of types of defects in the casting at the development stage. Parametrical changing of the gating system 3D model and variation of its characteristics, and repeated simulation of cooling, crystallization and mold filling processes can provide high quality casting.
Sublytic C5b-9 Induces IL-23 and IL-36a Production by Glomerular Mesangial Cells via PCAF-Mediated KLF4 Acetylation in Rat Thy-1 Nephritis
Authors: Zhang Jing , Xie Mengxiao , Xia Lu , Yu Tianyi , He Fengxia , Zhao Chenhui , Qiu Wen , Zhao Dan , Liu Yu , Gong Yajuan , Yao Chunyan , Liu Longfei , Wang Yingwei
Published: November 2018

Sublytic C5b-9 formation on glomerular mesangial cells in rat Thy-1 nephritis (Thy-1N), a model of human mesangioproliferative glomerulonephritis, is accompanied by the production of proinflammatory cytokines, but the relationship between sublytic C5b-9 and cytokine synthesis and the underlying mechanism remains unclear. To explore the problems mentioned above, in this study, we first examined the levels of proinflammatory ILs (e.g., IL-23 and IL-36a) as well as transcription factor (KLF4) and coactivator (PCAF) in the renal tissues of Thy-1N rats and in the glomerular mesangial cell line (HBZY-1) stimulated by sublytic C5b-9. Then, we further determined the role of KLF4 and PCAF in sublytic C5b-9–induced IL-23 and IL-36a production as well as the related mechanism. Our results showed that the levels of KLF4, PCAF, IL-23, and IL-36a were obviously elevated. Mechanistic investigation revealed that sublytic C5b-9 stimulation could increase IL-23 and IL-36a synthesis through KLF4 and PCAF upregulation, and KLF4 and PCAF could form a complex, binding to the IL-23 or IL-36a promoter in a KLF4-dependent manner, causing gene transcription. Importantly, KLF4 acetylation by PCAF contributed to sublytic C5b-9–induced IL-23 and IL-36a transcription. Besides, the KLF4 binding regions on IL-23 or IL-36a promoters and the KLF4 lysine site acetylated by PCAF were identified. Furthermore, silencing renal KLF4 or PCAF gene could significantly inhibit IL-23 or IL-36a secretion and tissue damage of Thy-1N rats. Collectively, these findings implicate that the KLF4/PCAF interaction and KLF4 acetylation by PCAF play a pivotal role in the sublytic C5b-9–mediated IL-23 and IL-36a production of Thy-1N rats.
Views of mothers on the fundamental role of the Christian father as mentor in a nuclear family environment
Authors: Freeks Fazel E.
Published: November 2018

The present empirical study explored and described the views of mothers elicited through in-depth interviews. This research followed an explorative, interpretive and descriptive qualitative design by using purposive voluntary sampling. Mothers were selected by their lived experience and knowledge of the father absence problem, leadership, prominence in society, and involvement in their community. Data was collected through in-depth interviews, and field notes were taken. The data was analysed through open coding. The results of the empirical research in which mothers were involved indicated that the Christian father as mentor is deemed crucial and relevant within current families. Mentoring by the father is vital in the lives of children and should be implemented and emphasised within the family context. As mentor, the father should nurture the children spiritually and shape their character, thus helping them become complete, whole and, by the grace of God, holy ‘before God’ (coram Deo).
Inter and intra- gender discourse in African prose: an interrogation of the female image in selected literary texts
Authors: Okpala Ebele Peace , Utoh-Ezeajugh Tracie Chima
Published: November 2018

Feminist writers have over the years portrayed patriarchy as the major and real source of female exploitation and subjugation and have highlighted the concept in their creative works. African female experiences, problems and yearnings are examined through the female character in the selected literary texts. Certain practices in the various cultural milieus, which not only demean women but also debar them from having a say in the daily affairs of the society are also exposed. The study interrogated some oppressive forces that marginalize women to determine if the factors are only inter gender. The paper revealed at the end of the study that truly women are subjected to discrimination, oppression and humiliation all through their lives and that these are both inter-gender and intra-gender. Patriarchy, as generally accepted, is not the sole source of female oppression because women seem to suffer oppression in the hands of fellow women especially in the African cultural milieu. The study employed the theories of Focu feminism, Snail Sense Feminism and Womanism in critical evaluations. To make adequate judgements, critical opinions of some scholars were reviewed. The study recommends love and empathy amongst women. It concludes that the oppression of women by the male gender will greatly be countered by women's collective activism, which can only be possible when they close ranks and unite.Keywords: Gender, Patriarchy, Oppression, Intra Gender, Women
Critique against social injustice in the Book of Amos: its relevance to development in Nigeria
Authors: Umeanolue Ikenna L.
Published: November 2018

In the Old Testament book of Amos, the basic message of prophet Amos stresses the divine demand for social justice and concern for the oppressed in 8th century Israel. Many among Israel’s wealthy members of the society at the time of Amos chose to be unjust and to treat the disadvantaged as they wished. Amos connects the injustice he sees around him to a society bent on wealth and prosperity while being forgetful of the true worship of God. As justice was denied in Amos’ time, so also it is being denied in contemporary Nigerian society. The research examined some of the social injustices observable in Nigeria such as socio-economic injustice, socio-political injustice, socio-religious injustice and socio-judicial injustice. It is the conclusion of this paper that for a meaningful development in Nigerian society, Nigerians should learn to practise social justice as demanded in the book of Amos.
Ethnicity and national integration in Nigeria: towards the use of indigenous language option for information dissemination at the grassroots
Authors: Uwaezuoke Aghaegbuna Haroldson
Published: November 2018

The linguistic complexity of Nigeria and the affinity of the indigenous languages to the diverse ethnic nationalities have made the issue of national integration become very worrisome and seem unattainable in the country. The different ethnic nationalities have continued to live in mutual distrust of one another. Apart from the National Policy on Education, which recognises Igbo, Hausa and Yoruba as the majority languages and also encourages every child to learn one of them in addition to the child’s mother tongue, government is yet to boldly come up with an official national language policy for Nigeria. In this paper, the use of indigenous languages to disseminate information to Nigerians, in addition to English, which is the country’s official language, is considered another option towards solving the country’s problem of national integration. The paper anchors on the Relevance theory. Earlier views of scholars are reviewed from where this paper veered. It is concluded with a suggestion that government policies and programmes should be translated into the indigenous languages and widely circulated for better awareness, understanding and participation/contribution of Nigerians to national issues. This would engender effective grassroots mobilisation for national integration and national development.Keywords: ethnicity, indigenous language and national integration
Disaggregation of fixed time interval rainfall to continuous measured rainfall for the purpose of design rainfall estimation
Authors: Gericke OJ , Pietersen JPJ
Published: November 2018

Design rainfall estimates are primarily used in single-event deterministic design flood estimation methods where estimates of the peak discharge are based on the critical storm duration or time of concentration (TC) of a catchment. Therefore, daily design rainfall depths used in flood estimations must either be decreased or increased from durations less than or longer than 24 hours to the design rainfall depths for a rainfall duration of TC. This paper presents the comparison of two South African methods used to convert or scale 1-day fixed time interval observed rainfall (08:00 to 08:00) to continuous measures of n-hour rainfall for selected TC durations at a quaternary catchment level, in the C5 secondary drainage region in South Africa as pilot case study. In each quaternary catchment, the annual maximum series (AMS) of the 1-day fixed time interval point rainfall were extracted, infilled, converted and scaled to appropriate continuous measures of TC-hour point rainfall using conversion factors (Adamson, 1981) and scaling factors (Smithers and Schulze, 2003), respectively. Thereafter, all the TC-hour observed point rainfall values were averaged to observed catchment rainfall at a quaternary catchment level using the Thiessen polygon method. In using the two methods to estimate continuous short-duration n-hour (TC ≤ 24 hours) and long-duration n-hour (TC > 24 hours) catchment rainfall from 1-day fixed time interval point rainfall, an acceptable (0.71 < r2 ≤ 0.86) and high (r2 ≥ 0.93) degree of association were achieved, respectively, despite the different approaches used in each method. Overall, the results confirmed that fixed time interval rainfall should be scaled to continuous measures of rainfall using the Smithers-Schulze scale invariance approach for various TC durations in the case study area. In comparison to the Adamson conversion methodology, the Smithers-Schulze scaling methodology is also based on a more extensive and recent rainfall database as incorporated in software for design rainfall estimation in modern flood hydrology practice in South Africa.
La investigación del discurso escrito en el aprendizaje de idiomas en entornos colaborativos y wiki
Authors: Díez Bedmar María Belén , Pérez Paredes Pascual
Published: November 2018

Es bien sabido que el uso de las nuevas tecnologías ha sido instrumental en la promoción del conocimiento digital y del aprendizaje colaborativo del lenguaje. Sin embargo, Bax (2003) ha visto en la comunicación asistida por ordenador un gran potencial en las etapas abierta y de normalización. Aunque un número importante de investigaciones en los últimos años se han dedicado a la comunicación asíncrona por medio de web 1.0, los esfuerzos realizados en la actualidad han comenzado a analizar el uso de herramientas de video síncronas (Jáuregui y Bañados, 2008), blogs (Murray y Hourigan, 2008) y wikis (Lund, 2008).

En este artículo presentamos una experiencia colaborativa en línea entre dos Instituciones de Educación Superior en Inglaterra y España (curso académico 2008/2009). Dicha experiencia ofreció a los alumnos la oportunidad de desarrollar su destreza escritora por medio de una serie de actividades de naturaleza digital en las que el wiki estaba integrado de forma natural. Los alumnos ingleses y españoles se embarcaron en la redacción de un folleto turístico de un monumento relevante desde el punto de vista histórico/artístico del otro país de forma colaborativa, ayudando al compañero en la redacción de su folleto y siendo ayudado de la misma manera.
Wikis en lenguas para fines específicos y su traducción
Authors: Lázaro Gutiérrez Raquel , Pena Díaz Carmen , Vitalaru Bianca
Published: November 2018

Las herramientas Wiki pueden llegar a ser muy útiles tanto en la enseñanza de lenguas en general como en la traducción, sobre todo si se tiene en cuenta que, hoy en día, dentro del nuevo marco del Espacio Europeo de Educación Superior, los docentes tienen que enfrentarse a dificultades como grupos numerosos de alumnos, pocas clases presenciales y competencias transversales añadidas al contenido de las materias. Por este motivo, que una herramienta como las wikis, que permita trabajar fuera del aula y con la cual el estudiante puede realizar trabajos individuales y en grupo, conectado y en contacto con el resto de sus compañeros y profesores, resulta especialmente útil. Mientras que la sencillez de estas herramientas permite al docente diseñar actividades atractivas y útiles con un esfuerzo y conocimientos tecnológicos relativamente mínimos, para los estudiantes supone una gran oportunidad para aprender a trabajar con las TIC y de manera grupal y colaborativa.

En este capítulo se describen las tareas y actividades que se diseñaron y pusieron en práctica para las asignaturas del Máster Oficial en Comunicación Intercultural, Interpretación y Traducción en los Servicios Públicos y para las asignaturas de inglés para fines específicos del postgrado y grado de la Facultad de Derecho de la Universidad de Alcalá, centrándonos de manera especial en su diseño, las dificultades y ventajas que plantearon y la respuesta que se obtuvo por parte del alumnado.
El diseño de una Wiki sobre ecoturismo como herramienta para el aprendizaje universitario de turismo en entorno virtual
Authors: González Reverté Francesc , Miralbell Izard Oriol
Published: November 2018

La experiencia consiste en la creación de una wiki sobre Ecoturismo organizada en torno al trabajo colectivo como objeto de aprendizaje de la evaluación continua para la asignatura de (Ecoturismo). Tiene dos objetivos de innovación: 1) el desarrollo de metodologías docentes aptas para el trabajo colaborativo, y 2) habituar al uso de las herramientas del web 2.0 a estudiantes y a docentes. Las principales aportaciones del proyecto han sido el diseño de una metodología novedosa de trabajo en equipo en entorno de aprendizaje virtual; y la integración de las entradas de la wiki como recurso docente. Las encuestas de satisfacción realizadas entre los estudiantes muestran la excelente acogida del proyecto. Los principales problemas detectados tienen que ver con las dificultades técnicas en la implementación de la wiki así como el exceso de carga docente que ha supuesto.
Los dilemas de la Educación Inclusiva: apostar por una re-contrucción y modernización de sus bases teóricas
Authors: González Aldo Ocampo
Published: November 2018

Se presenta un marco comprensivo sobre los desafíos de la investigación en educación inclusiva. Particularmente, se explican las condiciones gravitantes para iniciar la construcción de una epistemología de la educación inclusiva con foco en las tensiones vigentes en la historia de la cultura de nuestra región. Este trabajo tiene como propósito analizar las condiciones de producción que sustentan la experiencia discursiva de la educación inclusiva en nuestra región. Se intenta alinear criterios de validez que permitan esbozar un nuevo sistema de sustentación en educación inclusiva y promover las condiciones epistémicas más oportunas a esta reflexividad. A esto se agrega la comprensión transdisciplinaria de la mecánica de la exclusión. Se concluye visualizando la necesidad de apostar por un nuevo sistema de reflexividad permitirá superar los márgenes en los que habita la epistemología de las cegueras y enriquecer a través de nuestras propuestas epistémicas los diversos campos de la ciencia educativa en general. Un sistema epistémico en materia de educación inclusiva invita a levantar criterios para re-fundar la educación especial y asumir las transformaciones que la educación en términos más generales reclama hoy por sobre la imposición tradicional de su modelo.
Formação e saúde docente para a/na educação superior
Authors: Timm Jordana Wruck , Sengik Aline Sberse , Stobäus Claus Dieter
Published: November 2018

Objetivou-se pesquisar sobre os aspectos relacionados à saúde e à formação dos docentes universitários, bem como, realizar uma análise da produção apresentada nos últimos dois anos da Associação Nacional de Pesquisa em Educação (ANPED nacional) a respeito do tema e, a partir disso, construir um texto fundamentado sobre a docência na Educação Superior, alertando para a importância da formação nessa área e sua relação com a saúde do professor. Adotou-se como método a leitura flutuante no site da ANPED (35ª e 36ª reuniões nacionais, eixos “formação de professores” e “trabalho e educação”). Como principais resultados, foi possível observar a importância da formação docente para melhor qualificar os profissionais da educação. Em relação à saúde docente, a alta demanda de atividades (além das habituais), o nível de produção, o salário, as exigências para uma formação docente mais apropriada, entre outros fatores, tendem a comprometer a saúde dos professores. Em contrapartida, quando esses profissionais são valorizados, reconhecidos e respeitados pelo seu trabalho, há a promoção do bem-estar.
Incongruência entre concepções e práticas avaliativas das professoras pedagogas nos anos iniciais do ensino fundamental
Authors: Benvenutti Dilva Bertoldi
Published: November 2018

O estudo objetiva compreender a relação ente concepção e prática de avaliação das professoras pedagogas nos Anos Iniciais do Ensino Fundamental da Educação Básica. A pesquisa busca saber o que as professoras concebem como avaliação e como desenvolvem suas práticas no contexto dos Anos Iniciais do Ensino Fundamental. Nessa direção, foi realizada pesquisa de campo com vinte e quatro professoras dos anos iniciais, egressas do curso de Pedagogia da Universidade do Oeste de Santa Catarina de Maravilha-SC, formadas pela matriz 2004-2008. A pesquisa apresenta enfoque qualitativo, dialético e descritivo. Foi aplicado questionário, organizada uma sessão de grupo focal e fórum online (2014-2015). As professoras pesquisadas são representadas pelas siglas: PQ (questionário), PF (fórum online) e PGF (Grupo focal). A análise demonstra que os discursos das professoras pedagogas apresentam inconsistência com suas práticas de sala de aula, pois afirmam conceberem avaliação como diagnóstico e processo, mas em contrapartida em suas práticas dão ênfase ao modelo tecnicista, apontando trabalho, observação, provas, comportamento e atitudes como instrumentos utilizados para avaliar. A avaliação está pautada na verificação, tendo como foco somente os objetivos propostos, práticas direcionadas e controladas pelas professoras que dificilmente poderão ser entendidas como reflexivas ou vinculadas à autoavaliação. O desafio é as professoras pedagogas apresentarem posturas coerentes relacionadas às concepções e práticas, apresentando congruência entre o que dizem e o que fazem no contexto da sala de aula, possibilitando que a avaliação tenha como intuito diagnosticar aprendizagem, acompanhar o processo e refletir sobre ação na ação, permitindo que os alunos façam uma autoavaliação, suscitando práticas que demonstrem amor e responsabilidade.
A mediação pedagógica no gênero chat educacional numa disciplina da UNILAB-CE
Authors: Garantizado Júnior José Olavo Da Silva
Published: November 2018

O presente trabalho tem como objetivo discutir de que maneira o conceito mediação pedagógica pode lançar luzes no estudo da construção do conhecimento entre os participantes de sessões de chat educacional, sujeitos envolvidos no processo ensino/aprendizagem na modalidade de Educação a Distância (EaD). Para isso, empreendemos um esforço para discutir a categoria mediação pedagógica a partir das perspectivas teóricas de Vygotsky (1998), que conceitua a existência de uma mediação simbólica a partir de uma perspectiva interacional; Masetto (2000), o qual apresenta a competência dos professores universitários e as suas habilidades na modalidade Educação a Distância (EaD); Abreu (2002), que discutiu a necessidade de o professor conhecer e dominar o chat educacional para poder torná-lo um gênero eficaz na educação; Gutierrez e Prieto (1994) e Araújo (2006), que analisaram a construção sóciocolaborativa do conhecimento no gênero chat educacional. No que tange à modalidade de ensino EaD, partiremos dos trabalhos de Alves (1998) e Elias & Souza (2004), cujos trabalhos focalizam os aspectos historicistas e a importância dessa nova modalidade de ensino. Os resultados de nossa incursão pela literatura especializada sinalizam para a ressignificação que o professor sofre nos chats educacionais em que atua, assumindo a condição de mediador pedagógico.
Programa mais educação: análise das produções acadêmicas
Authors: Parente Cláudia Da Mota Darós , Prado Raquel Nakamura Almeida
Published: November 2018

O presente trabalho tem como objetivo apresentar o estado da arte das produções acadêmicas sobre o Programa Mais Educação, ação do Ministério da Educação destinada à ampliação da jornada escolar. A pesquisa foi realizada por meio de buscas no Banco de Teses da Capes (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior), considerando-se as informações disponíveis relativas aos anos de 2011 e 2012. O levantamento indicou a existência de 19 teses e dissertações produzidas sobre o Programa Mais Educação no período especificado, concentrando-se em oito temáticas: concepções e práticas educativas do programa; impactos do programa no rendimento escolar dos alunos; representações sociais sobre o programa; práticas de leitura e escrita nas oficinas do programa; o programa e as novas demandas para a gestão escolar; perfil docente e formação de professores que atuam no programa; a contribuição do programa na disseminação da cultura digital; a contribuição do programa para a erradicação do trabalho infantil. O presente artigo traz colaborações para a sistematização dos estudos sobre o Programa Mais Educação e para a formulação e implementação de políticas de educação integral em tempo integral.
A 900-year New England temperature reconstruction from in situ seasonally produced branched glycerol dialkyl glycerol tetraethers (brGDGTs)
Authors: Miller Daniel R. , Habicht M. Helen , Keisling Benjamin A. , Castañeda Isla S. , Bradley Raymond S.
Published: November 2018

Abstract. Paleotemperature reconstructions are essential for distinguishing
anthropogenic climate change from natural variability. An emerging method in
paleolimnology is the use of branched glycerol dialkyl glycerol tetraethers
(brGDGTs) in sediments to reconstruct temperature, but their application is
hindered by a limited understanding of their sources, seasonal production,
and transport. Here, we report seasonally resolved measurements of brGDGT
production in the water column, in catchment soils, and in a sediment core
from Basin Pond, a small, deep inland lake in Maine, USA. We find similar
brGDGT distributions in both water column and lake sediment samples but the
catchment soils have distinct brGDGT distributions suggesting that
(1) brGDGTs are produced within the lake and (2) this in situ production
dominates the down-core sedimentary signal. Seasonally, depth-resolved
measurements indicate that most brGDGT production occurs in late fall, and at
intermediate depths (18–30 m) in the water column. We utilize these
observations to help interpret a Basin Pond brGDGT-based temperature
reconstruction spanning the past 900 years. This record exhibits trends similar
to a pollen record from the same site and also to regional and global
syntheses of terrestrial temperatures over the last millennium. However, the
Basin Pond temperature record shows higher-frequency variability than has
previously been captured by such an archive in the northeastern United
States, potentially attributed to the North Atlantic Oscillation and volcanic
or solar activity. This first brGDGT-based multi-centennial
paleoreconstruction from this region contributes to our understanding of the
production and fate of brGDGTs in lacustrine systems.
PALEO-PGEM v1.0: A statistical emulator of Pliocene-Pleistocene climate
Authors: Holden Philip B. , Edwards Neil R. , Rangel Thiago F. , Pereira Elisa B. , Tran Giang T. , Wilkinson Richard D.
Published: November 2018

Abstract. We describe the development of the “Paleoclimate PLASIM-GENIE emulator” PALEO-PGEM and its application to derive a downscaled high-resolution spatiotemporal description of the climate of the last five million years. The 5-million-year time frame is interesting for a range of paleo-environmental questions, not least because it encompasses the evolution of humans. However, the choice of time-frame was primarily pragmatic; tectonic changes can be neglected to first order, so that it is reasonable to consider climate forcing restricted to the Earth's orbital configuration, ice-sheet state and the concentration of atmosphere CO2. The approach uses the Gaussian process emulation of the singular value decomposition of boundary-condition ensembles of the intermediate complexity atmosphere-ocean GCM PLASIM-GENIE. Spatial fields of bioclimatic variables of surface air temperature (warmest and coolest seasons) and precipitation (wettest and driest seasons) are emulated at 1,000 year intervals, driven by time-series of scalar boundary-condition forcing (CO2, orbit and ice-volume), and assuming the climate is in quasi-equilibrium. Paleoclimate anomalies at climate model resolution are interpolated onto the observed modern climatology to produce a high-resolution spatiotemporal paleoclimate reconstruction of the Pliocene-Pleistocene.
Enhanced pore space analysis by use of μ-CT, MIP, NMR, and SIP
Authors: Zhang Zeyu , Kruschwitz Sabine , Weller Andreas , Halisch Matthias
Published: November 2018

Abstract. We investigate the pore space of rock samples with respect to different petrophysical parameters using various methods, which provide data on pore size distributions, including micro computed tomography (μ-CT), mercury intrusion porosimetry (MIP), nuclear magnetic resonance (NMR), and spectral-induced polarization (SIP). The resulting cumulative distributions of pore volume as a function of pore size are compared. Considering that the methods differ with regard to their limits of resolution, a multiple-length-scale characterization of the pore space is proposed, that is based on a combination of the results from all of these methods. The approach is demonstrated using samples of Bentheimer and Röttbacher sandstone. Additionally, we compare the potential of SIP to provide a pore size distribution with other commonly used methods (MIP, NMR). The limits of resolution of SIP depend on the usable frequency range (between 0.002 and 100 Hz). The methods with similar resolution show a similar behavior of the cumulative pore volume distribution in the overlapping pore size range. We assume that μ-CT and NMR provide the pore body size while MIP and SIP characterize the pore throat size. Our study shows that a good agreement between the pore radius distributions can only be achieved if the curves are adjusted considering the resolution and pore volume in the relevant range of pore radii. The MIP curve with the widest range in resolution should be used as reference.
Pathways of ice-wedge degradation in polygonal tundra under different hydrological conditions
Authors: Nitzbon Jan , Langer Moritz , Westermann Sebastian , Martin Léo , Aas Kjetil Schanke , Boike Julia
Published: November 2018

Abstract. Ice-wedge polygons are common features of lowland tundra in the continuous permafrost zone and prone to rapid degradation through melting of ground ice. There are many inter-related processes involved in ice-wedge thermokarst and it is a major challenge to quantify their influence on the stability of the permafrost underlying the landscape. In this study we used a numerical modelling approach to investigate the degradation of ice-wedges with a focus on the influence of hydrological conditions. Our study area was Samoylov Island in the Lena River delta of Northern Siberia, for which we had in-situ measurements to evaluate the model. The tailored version of the CryoGrid3 Land Surface Model was capable of simulating the changing micro-topography of polygonal tundra and also regarded lateral fluxes of heat, water, and snow. We demonstrated that the approach is capable of simulating ice-wedge degradation and the associated transition from a low-centred to a high-centred polygonal micro-topography. The model simulations showed ice-wedge degradation under recent climatic conditions of the study area, irrespective of hydrological conditions. However, we found that wetter conditions lead to an earlier onset of degradation and cause more rapid ground subsidence. We set our findings in correspondence to observed types of ice-wedge polygons in the study area and hypothesized on remaining discrepancies between modelled and observed ice-wedge thermokarst activity. Our quantitative approach provides a valuable complement to previous, more qualitative and conceptual, descriptions of the possible pathways of ice-wedge polygon evolution. We concluded that our study is a blueprint for investigating thermokarst landforms and marks a step forward in understanding the complex interrelationships between various processes shaping ice-rich permafrost landscapes.
Il contatto linguistico nel medioevo lombardo
Authors: Brown Josh
Published: November 2018

La formazione di una koinè si può considerare la caratteristica principale dello sviluppo della lingua lombarda dal Quattrocento al Cinquecento. Fino a che punto Milano influenzasse la koinè lombarda è tuttavia ancora una questione aperta. Da un lato, alcuni studiosi sostengono che Milano svolgeva un ruolo di forza centralizzatrice per la “milanesizzazione” degli altri volgari lombardi, in modo simile a quanto accadeva in Piemonte e in Veneto. Dall’altro, molti studi negano a Milano questo ruolo sulla koinè lombarda e ribadiscono l’importanza di verificare se il prestigio di Milano influenzava i volgari non-milanesi. Il presente saggio considera fino a che punto Milano influenzava la koinè nella Lombardia del Quattrocento. Si prendono in esame otto fenomeni linguistici, descritti precedentemente come esclusivi del pavese, per analizzare la loro presenza o assenza in un corpus di testi religiosi scritti nel Quattrocento dalla suora Elisabetta di Pavia, e per verificare se si possono identificare elementi linguistici milanesi. Si considerano aspetti della fonologia e della morfologia nelle memorie di Elisabetta per dimostrare la formazione di una lingua prekoinè. L’articolo suggerisce la necessità di ridimensionare il ruolo di Milano nella storia dei volgari della Lombardia, sottolineando invece l’importanza delle fonti non-letterarie per il nord Italia e l’importanza attribuita ai capoluoghi nei processi di koineizzazione.
Las ‘creaciones expresivas’ del "Diccionario crítico etimológico castellano e hispánico" en contexto románico e indoeuropeo. Un nuevo (y a la vez antiguo) enfoque
Authors: Georgescu Simona
Published: November 2018

La similitud fonética y semántica entre un gran número de palabras de varios idiomas que sin embargo no se pueden reducir al mismo étimo le sugiere a Corominas (en el DCECH) un origen espontáneo en cada lengua, como resultado de la intención de reproducir por medios lingüísticos ciertas impresiones extra-lingüísticas. Tomando como punto de partida una selección de palabras categorizadas como ‘voces de origen expresivo’, analizamos la posibilidad y los límites de la creación léxica espontánea, en términos de fonosimbolismo y conceptos primarios expresados por onomatopeyas. Dado que el análisis comparativo de dichas palabras revela pautas semánticas y fonéticas recurrentes, no se puede rechazar por completo la idea de motivación lingüística (y en este sentido, intentamos rehabilitar la teoría de Hilmer, 1918), pero debemos situarla en el proto-románico, o, más probable, en el proto-indoeuropeo.