bluuebunny/crossref_metadata_2025 huggingface dataset:
La crise, une notion politique héritée des Grecs ?
Authors: Longhi Vivien
Published: April 2019

La crise politique ou historique est une notion polysémique et complexe qu’il peut être tentant d’expliquer par le lexique grec, ou par un retour à des textes anciens, médicaux ou historiques, qui feraient voir les origines de la notion. Or, contrairement à ce que certaines études avancent, on peine à trouver chez les Grecs, malgré l’existence de la notion de crise dans la médecine dite hippocratique, un mot ou une idée qui seraient l’équivalent de notre concept de crise politique. Connaissent-ils même seulement la métaphore politique de la crise que nous voulons leur attribuer ?
L’héritage de la métrique antique dans l’alexandrin français au xvie siècle
Authors: Denoyer Brice
Published: April 2019

L’alexandrin, au xvie siècle, en France, est loin d’avoir le succès qu’il connaîtra ensuite, que ce soit au théâtre ou dans la poésie. Nombre de facteurs peuvent expliquer l’émergence d’un vers alors cantonné à des utilisations périphériques : évolution du français moderne, rapport complexe entre l’alexandrin et la rhétorique politique (le vers prend une dimension prestigieuse associée à la forme du pouvoir royal, comme quand Robert Garnier décide d’écrire en alexandrins un Hymne à la monarchie), etc. L’une de ces raisons est la relation que les poètes français entretiennent avec la métrique et la poésie antique, notamment à travers le théâtre. Confrontés à une poésie dramatique dont la prosodie leur est étrangère, ces poètes français (Lazare de Baïf, Guillaume Bochetel, entre autres), armés de leur connaissance des théories métriques des Anciens, vont en fait adapter ces dernières, dans un étrange syncrétisme qui va faire émerger l’alexandrin comme vers par excellence du dialogue tragique, notamment par la traduction des tragédies antiques.
Axiologie critique de La Mesnardière
Authors: Šuman Záviš
Published: April 2019

Cette étude examine les fondements et les filiations de la Poétique de La Mesnardière et le rôle que cet ouvrage a joué dans la réception des tragiques anciens (Eschyle, Sophocle, Euripide, Sénèque) dans la France du xviie siècle. En suivant la chronologie, elle tâche de dégager la logique qui préside, chez le poéticien, à la mise en place d’exemples et de contre-exemples des catégories structurales et des concepts constitutifs de la tragédie (mœurs, émotions tragiques, anagnorisis, exemplarité). L’analyse des jugements et de l’argumentation de La Mesnardière contribue à rendre plus perceptibles les soubassements théoriques sur lesquels repose la conceptualisation essentiellement moralisatrice du genre hégémonique dans la France de la première modernité.
Cumulative Damage Model for Glass-Fiber Reinforced Composites under Two Blocks Loading
Authors: Athmane Sid Ahmed , Abdelkader Djebli , Mostefa Bendouba , Abdelkrim Aid , Belabbess Bachir Bouiedjra
Published: April 2019

A fatigue damage accumulation model for composite materials is proposed. There is unanimity on the complex nature of the mechanisms of damage inherent to these types of materials. This led to proposals for nonlinear models, but relatively expensive in experimental requirements and determination of parameters. Thus, the proposed model is simple and does not require parameters apart the ultimate strength and the fatigue curve. A program is developed to allow the follow-up of the damage evolution during the cycles of loading. The proposed model is applied to E-Glass/Epoxy [0°/90°] under two blocks loading. Prediction results are relatively good and fit well with the experimental results compared to similar models.
Comprehending Occurrence of Premature Failure in Compressor Turbine (CT) Blades for Short-Haul Aircraft Fleet
Authors: Ngoret Joshua Kimtai , Kommula Venkata Parasuram
Published: April 2019

This paper presents results from modeling of Compressor Turbine (CT) blades for short-haul aircraft fleet occasioned by thermo-mechanical stresses in order to comprehend the occurrence of premature failure. A 3D PT6A-114A engine high pressure (HP) CT blade geometrical model was developed in commercial CAD-SolidWorks, then imported to ANSYS 15.0 environment for finite element analysis (FEA). The CT blade was investigated for transient thermal stresses from heat generated by the combustors and static structural stresses from rotational velocities of the engine which account for 80% of inertial field during flight. The results revealed that the blades could have served for another 1.44% of the time they were in service.
Study of Concretes Reinforced by Plastic Fibers Based on Local Materials
Authors: Hadj Mostefa Adda , Slimane Merdaci
Published: April 2019

This work is carried out to investigate the performance of concrete reinforced with plastic fibers obtained locally (bottle waste as fiber). Bottle waste plastic was chosen because it is being thrown after single use and cause environmental problem. One way to recycle wasted bottles plastic is grinded into irregular fiber. Then, it was incorporate with the concrete and tests the performance of the concrete. The study was conducted using cylindrical and rectangular (cube) mold of concrete to investigate the performance of the concrete in term of mechanical properties. In this research, the mechanical properties that were measured are compressive strength, splitting tensile strength and flexural strength. The results revealed that the presence of plastic fiber in concrete will increase the concrete performance, as well as the concrete bond strength is improved and the cracks in the concrete decrease the use of fibers and reduce plastic waste.
A Bayesian Model for Optimum Supply of Spare Parts
Authors: Bounou Oumaima , El Barkany Abdellah , El Biyaali Ahmed
Published: April 2019

The need to have a stock of spare parts in a production company is very important in order to contract a continuity of service assurance. The costs of the stock are the costs of ownership, the costs of purchases and the costs of breaking the stock. In summary, the estimation of the needs of the stock is done mostly through quantitative methods while minimizing the costs.In this paper, we will first present our Bayesian model developed taking into account the obsolescence risk that is related to the life of parts, in order to determine the combination of new and recycled parts in quantities. After, we will expose some of the decision results of the simulation in order to clarify the operation of the bayesian networks. Finally, we will compare our model with the existing reference model and the bootstrap method for the purpose to see the influence of the parameters considered.
Fiber-Optic Interferometric Sensor for Dynamic Impact Measurement of Transport Trucks
Authors: Stolárik Martin , Nedoma Jan
Published: April 2019

Ground vibrations are commonly observed by using a standard seismic station equipped with speed seismometers or acceleration seismometers. The seismometers include three mechanical vibrating systems (sensors) and the primary output is the wave pattern of recording velocity or acceleration of the material point oscillation. An alternative new method how it is possible to realize seismic measurements is using of the fiber-optic interferometric sensors. These interferometers are well-known for their ability to make high-precision measurements of optical path difference or changes that may be induced by a refractive index change in the interferometer or a physical displacement. The paper presents a comparison of the results of the standard seismic measurement by using seismic station and of the fiber-optic interferometric sensor. As a source of dynamic load, truck transport was chosen. When trucks passing through unevenness on the road (due to the road damage, the transition area of the bridge etc.), it generates vibrations that are transmitted to the subsoil and can adversely affect the surrounding building objects. Data comparison of the subsoil dynamic response obtained during both approaches of measurements is present in the amplitude and primary in the frequency domain.
Hydration, Shrinkages and Mechanical Properties of Ultra High Performance Concrete Containing Blast Furnace Slag and Algerian Dune Sand
Authors: Zenati Abdelfetah , Tahlaiti Mahfoud , Khelidj Abdelhafid , Oudjit Mohamed Nadjib
Published: April 2019

The new requirements for strength and durability have led to the development of Ultra High Performance concrete (UHPC) with outstanding mechanical properties and durability. However, the application of this type of concrete is exceptional, because of the high dosage of cement and the incorporation of expensive materials, such as silica fume (SF) whose dosage can reach 30% by weight of cement. This type of concrete is formulated on two bases: A fine granular skeleton (max diameter 630μm) and high cementitious materials content. The search for local materials to exploit them in the formulation of UHPC is the current trend. It is therefore necessary to control their effect on the behavior and evolution of cement hydration.The objective of this study is to highlight the influence of blast furnace (BFS) on hydration kinetics, linear endogenous shrinkage and chemical shrinkage at very early age (before 72h), drying shrinkage after hardening, as well as, the evolution of mechanical compressive strengths as a function of time. In addition, the exploitation of dune sand in the granular skeleton is an alternative to reduce the crushing energy and avoid microcracks possibly induced.The analysis of the results showed the interest of the use of the dune sand and the partial substitution of the cement by the BFS on the properties of the UHPCs in the fresh state and in the hardened state.In addition to the high performance achieved by UHPCs, their use, in Algeria, will meet both economic and ecological requirements given the abundance of very fine dune sand (southern Algeria) and complex blast furnace BFS of EL-Hadjar (Eastern Algeria).
Aging changes complexity of heart rate dynamics assessed by entropy and Lyapunov exponent analysis
Authors: Siciliano Roberto , Agapito Giuseppe , Siciliano Sarah , Fimognari Filippo Luca
Published: April 2019

In recent years, many research groups are trying to quantify the physiological signals of an individual, proposing new models to assess the complex dynamics of biological control systems. Indeed, life coincides with the good handling of the structures in the organism and of physiological control mechanisms, while disease and death coincide with the loss of structure and of coordinated functions. The homeodynamic systems which normally govern health are the same that cause pathological events when activated inadequately, or rather, when the balance between order and chaos of the elementary physiological processes is no longer effectively controlled in relation to any type of stress, both external and internal to the body. In a complex system, loss or alteration of communication between physiological signals means pathology. In this paper a signal analysis method based on Entropy (E), Lyapunov exponent (1), Median Absolute Deviation (MAD), Multiscale Entropy (MSE), is proposed to estimate the complexity of long-range temporal correlation heart rate (HR) time series for an elderly person and a young person both healthy. These new methods could improve overall understanding of the physiological system of the human organism, by adopting new models and experimental paradigms, such as those of fractality and entropy, who have the ability to direct from an organ medicine to a modern systemic medicine.
Implementation and evaluation of the Presto combined qualitative real-time assay for Chlamydia trachomatis and Neisseria gonorrhoeae in Rwanda
Authors: Cuylaerts Vicky , De Baetselier Irith , Muvunyi Claude M. , Mwambarange Lambert , Smet Hilde , Rusine John , Musengamana Viateur , Van de Wijgert Janneke , Crucitti Tania
Published: April 2019

Background: The Presto combined qualitative real-time assay for Chlamydia trachomatis and Neisseria gonorrhoeae (Presto CT/NG PCR assay) is appealing for developing countries, because it can be used with multiple DNA extraction methods and polymerase chain reaction (PCR) platforms.Objectives: The objective of the study was to implement and evaluate the Presto CT/NG PCR assay at the National Reference Laboratory (NRL) in Kigali, Rwanda, where no real-time PCR assays for the detection of C. trachomatis or N. gonorrhoeae were available.Methods: The Presto CT/NG PCR assay was first evaluated at the Institute of Tropical Medicine (ITM) in Antwerp, Belgium. Next, NRL laboratory technicians were trained to use the assay on their ABI PRISM 7500 real-time PCR instrument and their competencies were assessed prior to trial initiation. During the trial, endocervical swabs were tested at the NRL, with bi-monthly external quality control testing monitored by the ITM. The final NRL results were evaluated against extended gold standard testing at the ITM, consisting of the Abbott m2000 RealTime System with confirmation of positive results by an in-house real-time PCR assay for C. trachomatis or N. gonorrhoeae.Results: Of the 192 samples analysed using the Presto assay at the NRL, 16 samples tested positive for C. trachomatis and 17 tested positive for N. gonorrhoeae; four of these were infected with both. The sensitivity and specificity of the Presto assay were 93.3% (95% confidence interval [CI]: 68.1% – 99.8%) and 99.4% (95% CI: 96.8% – 100%) for C. trachomatis and 100% (95% CI: 76.8% – 100%) and 98.8% (95% CI: 95.8% – 99.9%) for N. gonorrhoeae.Conclusion: C. trachomatis and N. gonorrhoeae testing with the Presto assay was feasible in Kigali, Rwanda, and good performance was achieved.
Dermoscopy of Rare Pigmented Variant of Bowen's Disease
Authors: Sharma Aseem , Ghate Smita , Dhurat Rachita , Agarwal Shilpi A , Agarwal Sandip
Published: April 2019

How to cite this article

Agarwal SA, Dhurat RS, Agarwal S, Sharma A, Ghate S. Dermoscopy of Rare Pigmented Variant of Bowen's Disease. Int J Dermoscop 2017;1(2):56-59.
Dermoscopy in the Diagnosis of Scabies
Authors: Jakhar Deepak , Grover Chander
Published: April 2019

Scabies is one of the most common skin infestations and the diagnosis is mostly based on clinical presentation and suggestive history. A confirmatory diagnosis is highly desirable as the treatment requires strict compliance from the patient as well as close contacts. Existing diagnostic methods are time consuming and not very sensitive. This article describes the use of dermoscopy to facilitate the in-vivo diagnosis of this infestation.

How to cite this article

Grover C, Jakhar D. Dermoscopy in the Diagnosis of Scabies. Int J Dermoscop 2017;1(2):67-68.
Família, trabalho e racionalização: a reconfiguração dos espaços de moradia em uma usina de açúcar nas décadas de 1960-1990
Authors: Prado Marcos Lázaro
Published: April 2019

A gestão da força de trabalho assume diversas conigurações. De acordo com contextos especíicos, observa-se o surgimento de articulações em que a relação capital trabalho foi ampliada para além das condições objetivas. Um desses contextos foi aquele que se formou entre os anos 1960 a 1990 nas áreas produtoras de cana-de-açúcar do interior do estado de São Paulo, Brasil. Em uma das maiores usinas de açúcar e álcool do mundo – a Usina São Martinho – a concessão da moradia, a apropriação do trabalho familiar e a relação entre patrões e empregados assumiram uma lógica distinta, multifacetada, distante daquela comumente encontrada no universo das relações do mundo rural. O presente estudo é fruto de pesquisa de campo em que resgatamos a trajetória de trabalhadores cujas famílias se vincularam por gerações à usina. Buscamos evidenciar o caráter distinto das relações ali estabelecidas dentro de um recorte temporal especíico, a percepção dessas relações entre os trabalhadores e as razões que levaram ao seu inevitável desaparecimento.
Mesospheric anomalous diffusion during noctilucent cloud scenarios
Authors: Laskar Fazlul I. , Stober Gunter , Fiedler Jens , Oppenheim Meers M. , Chau Jorge L. , Pallamraju Duggirala , Pedatella Nicholas M. , Tsutsumi Masaki , Renkwitz Toralf
Published: April 2019

Abstract. The Andenes specular meteor radar shows meteor trail diffusion rates increasing on average by
about 10 % at times and locations where a lidar observes noctilucent
clouds (NLCs). This high-latitude effect has been attributed to the presence
of charged NLC after exploring possible contributions from thermal tides. To
make this claim, the current study evaluates data from three stations at
high, middle, and low latitudes for the years 2012 to 2016 to show that NLC
influence on the meteor trail diffusion is independent of thermal tides. The
observations also show that the meteor trail diffusion enhancement during NLC
cover exists only at high latitudes and near the peaks of NLC layers. This
paper discusses a number of possible explanations for changes in the regions
with NLCs and leans towards the hypothesis that the relative abundance of
background electron density plays the leading role. A more accurate model of
the meteor trail diffusion around NLC particles would help researchers
determine mesospheric temperature and neutral density profiles from meteor
radars at high latitudes.
Applying FP_ILM to the retrieval of geometry-dependent effective Lambertian equivalent reflectivity (GE_LER) to account for BRDF effects on UVN satellite measurements of trace gases, clouds and aerosols
Authors: Loyola Diego G. , Xu Jian , Heue Klaus-Peter , Zimmer Walter
Published: April 2019

Abstract. The retrieval of trace gas, cloud and aerosol measurements from ultraviolet, visible and near-infrared (UVN) sensors requires precise information on the surface properties that are traditionally obtained from Lambertian equivalent reflectivity (LER) climatologies. The main drawbacks of using such LER climatologies for new satellite missions are (a) climatologies are typically based on previous missions with a significant lower spatial resolution, (b) they usually do not fully take into account the satellite viewing dependencies characterized by the bidirectional reflectance distribution function (BRDF) effects, and (c) climatologies may differ considerably from the actual surface conditions especially under snow/ice situations. In this paper we present a novel algorithm for the retrieval of geometry-dependent effective Lambertian equivalent reflectivity (GE_LER) from UVN sensors based on the full-physics inverse learning machine (FP_ILM) retrieval. The radiances are simulated using a radiative transfer model that takes into account the satellite viewing geometry and the inverse problem is solved using machine learning techniques to obtain the GE_LER from satellite measurements. The GE_LER retrieval is optimized for the trace gas retrievals using the DOAS algorithm and the large amount of data of the new atmospheric Sentinel satellite missions. The GE_LER can either be used directly for the computation of AMFs using the effective scene approximation or a global gapless geometry-dependent LER (G3_LER) daily map can be easily created from the GE_LER under clear-sky conditions for the computation of AMFs using the independent pixel approximation. The FP_ILM GE_LER algorithm is applied to measurements of TROPOMI launched in October 2017 on board the EU/ESA Sentinel-5 Precursor (S5P) mission. The TROPOMI GE_LER/G3_LER results are compared with climatological OMI LER data and the advantages of using GE_LER/G3_LER are demonstrated for the retrieval of total ozone from TROPOMI.
Probabilistic forecasting of plausible debris flows from Nevado de Colima (Mexico) using data from the Atenquique debris flow, 1955
Authors: Bevilacqua Andrea , Patra Abani K. , Bursik Marcus I. , Pitman E. Bruce , Macías José Luis , Saucedo Ricardo , Hyman David
Published: April 2019

Abstract. We detail a new prediction-oriented procedure aimed at volcanic hazard
assessment based on geophysical mass flow models constrained with
heterogeneous and poorly defined data. Our method relies on an itemized
application of the empirical falsification principle over an arbitrarily wide
envelope of possible input conditions. We thus provide a first step towards a
objective and partially automated experimental design construction. In
particular, instead of fully calibrating model inputs on past observations,
we create and explore more general requirements of consistency, and then we
separately use each piece of empirical data to remove those input values that
are not compatible with it. Hence, partial solutions are defined to the inverse
problem. This has several advantages compared to a traditionally posed
inverse problem: (i) the potentially nonempty inverse images of partial
solutions of multiple possible forward models characterize the solutions to
the inverse problem; (ii) the partial solutions can provide hazard estimates
under weaker constraints, potentially including extreme cases that are
important for hazard analysis; (iii) if multiple models are applicable,
specific performance scores against each piece of empirical information can
be calculated. We apply our procedure to the case study of the Atenquique
volcaniclastic debris flow, which occurred on the flanks of Nevado de Colima
volcano (Mexico), 1955. We adopt and compare three depth-averaged models
currently implemented in the TITAN2D solver, available from https://vhub.org
(Version 4.0.0 – last access: 23 June 2016). The associated inverse problem
is not well-posed if approached in a traditional way. We show that our procedure
can extract valuable information for hazard assessment, allowing the exploration
of the impact of synthetic flows that are similar to those that occurred in the
past but different in plausible ways. The implementation of multiple models is
thus a crucial aspect of our approach, as they can allow the covering of other
plausible flows. We also observe that model selection is inherently linked to
the inversion problem.
Assimilation of wind data from airborne Doppler cloud-profiling radar in a kilometre-scale NWP system
Authors: Borderies Mary , Caumont Olivier , Delanoë Julien , Ducrocq Véronique , Fourrié Nadia
Published: April 2019

Abstract. The article reports on the impact of the assimilation of wind vertical
profile data in a kilometre-scale NWP system on predicting heavy
precipitation events in the north-western Mediterranean area. The data
collected in diverse conditions by the airborne W-band radar RASTA (Radar
Airborne System Tool for Atmosphere) during a 45-day period are assimilated
in the 3 h 3DVAR assimilation system of AROME. The impact of the length of
the assimilation window is investigated. The data assimilation experiments
are performed for a heavy rainfall event, which occurred over south-eastern
France on 26 September 2012 (IOP7a) and over a 45-day cycled period. Results
indicate that the quality of the rainfall accumulation forecasts increases
with the length of the assimilation window, which recommends using
observations with a large period centred on the assimilation time. The
positive impact of the assimilation of RASTA wind data is particularly
evidenced for the IOP7a case since results indicate an improvement in the
predicted wind at short-term ranges (2 and 3 h) and in the 11 h
precipitation forecasts. However, in the 45-day cycled period, the comparison
against other assimilated observations shows an overall neutral impact.
Results are still encouraging since a slight positive improvement in the 5,
8 and 11 h precipitation forecasts was demonstrated.
Inverting Rayleigh surface wave velocities for crustal thickness in eastern Tibet and the western Yangtze craton based on deep learning neural networks
Authors: Cheng Xianqiong , Liu Qihe , Li Pingping , Liu Yuan
Published: April 2019

Abstract. Crustal thickness is an important factor affecting lithospheric structure and
deep geodynamics. In this paper, a deep learning neural network based on a
stacked sparse auto-encoder is proposed for the inversion of crustal
thickness in eastern Tibet and the western Yangtze craton. First, with the
phase velocity of the Rayleigh surface wave as input and the theoretical
crustal thickness as output, 12 deep-sSAE neural networks are constructed,
which are trained by 380 000 and tested by 120 000 theoretical models. We
then invert the observed phase velocities through these 12 neural networks.
According to the test error and misfit of other crustal thickness models, the
optimal crustal thickness model is selected as the crustal thickness of the
study area. Compared with other ways to detect crustal thickness such as
seismic wave reflection and receiver function, we adopt a new way for
inversion of earth model parameters, and realize that a deep learning neural
network based on data driven with the highly non-linear mapping ability can
be widely used by geophysicists, and our result has good agreement with
high-resolution crustal thickness models. Compared with other methods, our
experimental results based on a deep learning neural network and a new
Rayleigh wave phase velocity model reveal some details: there is a
northward-dipping Moho gradient zone in the Qiangtang block and a relatively
shallow north-west–south-east oriented crust at the Songpan–Ganzi block.
Crustal thickness around Xi'an and the Ordos basin is shallow, about 35 km.
The change in crustal thickness in the Sichuan–Yunnan block is sharp, where
crustal thickness is 60 km north-west and 35 km south-east. We conclude
that the deep learning neural network is a promising, efficient, and
believable geophysical inversion tool.
The Impact of Climate on Surging at Donjek Glacier, Yukon, Canada
Authors: Kochtitzky William , Winski Dominic , McConnel Erin , Kreutz Karl , Campbell Seth , Enderlin Ellyn M. , Copland Luke , Williamson Scott , Main Brittany , Dow Christine , Jiskoot Hester
Published: April 2019

Abstract. Links between climate and glacier surges are not well understood, but are required to enable prediction of glacier surges and mitigation of associated hazards. Here, we investigate the role of snow accumulation and temperature on surge periodicity, glacier area changes, and timing of surge initiation since the 1930s for Donjek Glacier, Yukon, Canada. Snow accumulation measured in three ice cores collected at Eclipse Icefield, at the head of the glacier, indicate that a cumulative accumulation of 13.1–17.7 m w.e. of snow occurred in the 10–12 years between each of its last eight surges. This suggests that a cumulative accumulation threshold must be passed before the initiation of a surge event, although it remains unclear whether the relationship between cumulative snowfall and surging is due to the consistency in repeat surge interval and decadal average precipitation, or if it is indeed a prerequisite to surging. We also examined the 1968 to 2017 climate record from Burwash Landing, 30 km from the glacier, to determine whether a relationship exists between surge periodicity and an increase of 2.5 °C in mean annual air temperature over this period. No such relationship was found, although each of the past 8 surge events has been less extensive than the previous, with the terminus area approximately 7.96 km2 smaller after the 2012–2014 surge event compared to the ~ 1947 surge event. This study shows that the impacts of climate and surging is not yet understood and suggests that internal glacier processes may play a more important role in controlling glacier surge events.
Resolución de problemas y regulación del aprendizaje
Authors: Deulofeu Piquet Jordi , Vilallonga Pons Joana
Published: April 2019

El desarrollo de la resolución de problemas en el aula presenta múltiples facetas, una de las cuales se refiere a la evaluación y particularmente al uso de instrumentos evaluativos que contribuyan a la mejora del aprendizaje y que sirvan al propio resolutor para reflexionar sobre sus producciones y su manera de proceder. En este artículo se muestra como el uso de una base de orientación para la resolución de problemas puede constituir efectivamente una ayuda cuando los alumnos resuelven problemas. En particular se analiza la relación entre el número de acciones de la base de orientación que cada uno de los alumnos ha tomado en consideración al resolver un problema y sus soluciones al problema. La existencia de dicha relación permite considerar la base de orientación como un andamiaje educativo para la resolución de problemas.

Problem solving classroom practices have multiple facets. One of them is related to the evaluation and, consequently, the use of evaluation devices that enhance students’ learning as they help the students to reflect on their own outcomes. In this article we analyse the use of an orientation basis as a device to support first year secondary students’ mathematical problem solving. In particular, we study the relation between the number of actions of the orientation basis in which the students were involved when they solved a problem and their solutions to the problem. The emerging existence of this relationship allows us to consider the orientation basis as a problem-solving-related form of selfscaffolding.
Experimentar con TIC en la formación inicial de profesores
Authors: Lopes Natália , Gomes Anabela
Published: April 2019

En una sociedad en la que las tecnologías poseen cada vez mayor relevancia, son varios los argumentos que justifican su integración en la escuela. Efectivamente, el uso de las Tecnologías de la Información y Comunicación surge como una gran y valiosa posibilidad de cambio, ofreciendo al proceso de enseñanza-aprendizaje un nuevo soporte. Parece evidente que su uso constituye un hecho inevitable al que ningún docente debería permanecer indiferente. Esta es la finalidad del artículo, al preocuparse por la importancia de utilizar las TIC en el contexto de prácticum. Para ello, se presenta un relato de diez seminarios de practicum realizados en la Universidad de Trás-os-Montes e Alto Douro (Portugal), con futuros/as profesores/as de diferentes áreas de enseñanza básica y su potencial formativo. En este contexto, se recurre al uso de diferentes tecnologías para presentar herramientas susceptibles de ser usadas en las aulas,mostrar su utilidad en la futura práctica pedagógica y dejar indicadores para que los futuros docentes pudiesen elaborar materiales pedagógicos digitales capaces de responder a sus intenciones didácticas y, también, a los ambientes de aprendizaje que crean conforme a sus características y estilos de aprendizaje. Se concluye con una reflexión sobre la pertinencia de estos seminarios y la utilidad de las TIC en el contexto del prácticum.

In a society in which technologies have increasing relevance, there are several arguments for their inclusion in school. Indeed, the use of Information and Communication Technology emerges as a great and valuable possibility of change, a new support of teaching-learning processes. It seems clear that its use constitutes an unavoidable fact to which no teacher should remain indifferent. This is the purpose of this article which focuses on the importance of ICT in the context of practicum placements. To this extent, we describe 10 seminars about practicum placements in the Trás-os-Montes y Alto Douro University (Portugal), with future teachers of elementary education. During these seminars some ICT tools were presented so that students could check how they could use those tools in their lessons, show their usefulness in their future teaching and leave advice on how future teachers might elaborate digital pedagogical materials which respond to their educational intentions and to different learning environments according to learning characteristics and styles. It concludes by highlighting the relevance of these seminars and the usefulness of ICT in the context of practicum placements.
Estado actual de la Didáctica General: vicisitudes y controversias
Authors: Pérez Ferra Miguel , Rivas Flores Ignacio , Quijano López Rocío , Leite Méndez Analía
Published: April 2019

El presente estudio responde a unas reflexiones que analizan a nivel macro, meso y micro la estructura y vertebración de las acciones que pone en marcha el neopositivismo, a fin de neutralizar la ciencia didáctica mediante intervenciones complementarias que suponen desencuentros con el mencionado ámbito disciplinar. La acción del neopositivismo subvierte la verdadera finalidad del hecho educativo, orientado a la perfección de las personas; neutraliza el desarrollo de la Didáctica como ciencia, anulando su función tecnológica que media y guía, y sustituyendo la acción didáctica por eslóganes que responde a improntas más próximas a la ocurrencia que al saber hacer. Esta realidad se filtra en el ámbito de las aulas, impidiendo una gestión adecuada del hecho educativo ante las necesidades del alumnado, generando cambios en la comprensión de los fenómenos y realidades que desvinculan a las personas de sus verdaderas identidades, con explicaciones ajenas a la realidad de su naturaleza.

This study explores the actions that neopositivism undertakes at macro, meso and micro levels in order to neutralize the understanding of didactics as a science. Such actions consist of complementary interventions aimed at producing disagreements with the aforementioned academic field. Neopositivism subverts the true purpose of the educational fact, which seeks to make people better. It neutralizes the development of didactics as a science by annulling its technologic function, which mediates and guides, and by replacing didactic actions for slogans which are closer to witty remarks than to knowhow. This reality reaches classrooms, impeding the proper management of the educationalfact and students’ needs. This generates changes in the understanding of phenomena and realities, which disassociates people from their true identities with explanations unrelated to the reality of their nature.
Evaluación de objetos digitales de aprendizaje musical en Moodle
Authors: Espigares Pinazo Manuel Jesús , Bautista Vallejo José Manuel
Published: April 2019

Este estudio presenta la aplicación de procesos automatizados de análisis a objetos digitales de aprendizaje musical online, mediados por una plataforma telemática. A nivel teórico, se basa en la aplicación de los principios del aprendizaje virtual, la educación personalizada y la aplicación de procesos automatizados de análisis de datos educativos. En concreto, se plantea la aplicación de dichas técnicas a los test de evaluación inicial, para medir niveles de conocimientos previos en la materia. El análisis de la información se efectúa a partir de los datos recogidos en una herramienta para la elaboración de cursos online, Moodle. A partir de dichos datos se halla un modelo, denominado k-medias (k-means en lengua inglesa), que permite clasificar los diferentes niveles de conocimientos musicales. El modelo elaborado establece tres perfiles en cuanto al nivel de aprendizaje musical del alumnado: nivel alto, medio y bajo.

This study presents the application of automated analysis processes to digital objects in online music learning, mediated through a telematic platform. Theoretically, the study is based on the application of the principles of e-learning, personalized education and implementation of automated processes for analysing educational data. Specifically, this study taps into the application of such techniques to initial test assessment, with a view to measuring levels of subject knowledge. The analysis of the information is undertaken from the data collected in a tool for making online courses, Moodle. From the analysis of these data a model, called k-means, emerges which classifies the different levels of musical knowledge. The model establishes three profiles regarding acquisition of music knowledge: high, medium and low.
ADSORPCIJA PROPAN KISELINE NA VISOKOSILIKATNIM ZSM-5 ZEOLITIMA NANOSTRUKTURNIH DIMENZIJA
Authors: Sladojević Slavica , Penavin- Škundrić Jelena , Levi Zora , Bodroža Darko , Lazić Dragica , Škundrić Branko
Published: April 2019

U radu je praćena adsorpcija propan kiseline iz vodenog rastvora na visokosilikatim zeolitnim uzorcima, proizvedenim savremenim nanotehnologijama u američkoj kompaniji Zeolyst International (oznaka: CBV 28014). Kao adsorbensi korišteni su NH 4 ZSM-5 zeolit i njegova modifikovana forma-HZSM-5 (molski odnos SiO 2 /Al 2 O 3 iznosi 280). Adsorpcija je praćena u temperaturnom intervalu od 283 K do 303 K. Rezultati su pokazali da je sa porastom temperature adsorpcije količina adsorbovane propan kiseline rasla i na izvornoj i na modifikovanoj formi ZSM-5 zeolita, što ukazuje da se pored fizičke adsorpcije dešava i hemisorpcija, pri čemu su molekule kiseline vezane za aktivne centre i čvršćim hemijskim vezama. Modifikacijom osobina izvornog zeolita dobio se bolji adsorbens (HZSM-5 zeolit) za propan kiselinu, što je i očekivano obzirom na izražen hidrofobni karakter ove modifikovane forme.
ISPITIVANJE UTICAJA FEROCENA I NJEGOVIH DERIVATA NA AKTIVNOST PROTEOLITIČKIH ENZIMA PRISUTNIH U LIZATU E. COLI ATCC 25922
Authors: Žabić Mirjana , Kukrić Zoran , Topalić- Trivunović Ljiljana
Published: April 2019

Sve značajnija upotreba organometalnih jedinjenja u terapeutske svrhe je potakla mnoga istraživanja u oblasti inhibicije enzima. U ovom radu je ispitivan efekat ferocena i njegovih derivata na proteolitičke enzime prisutne u lizatu Esherichia coli ATCC 25922. Utvrđeno je da ferocen najviše, skoro za 50%, smanjuje brzinu nastajanja p-nitroanilina iz N-α-benzoil-DL-arginin p-nitroanilida (BAPNA) uz pomoć enzima lizata bakterije E. coli. Dakle, za inhibiciju hidrolize BAPNA-e pomoću lizata ove bakterije i sam ferocen je bio dovoljno djelotvoran, iako je bilo za očekivati da će uvođenje poželjnih funkcionalnih grupa u molekulu ferocena poboljšati inhibiciju tripsina ostvarivanjem bolje interakcije sa enzimskim aktivnim mjestom.
UTICAJ ELEKTRODNOG MATERIJALA NA ANODNU OKSIDACIJU CIJANIDNIH OTPADNIH VODA
Authors: Malinović Borislav , Pavlović M. , Mandić Jovo
Published: April 2019

Anodna oksidacija je elektrolitička elektrodna reakcija. Ovim postupkom se uspješno vrši oksidacija cijanidnih otpadnih voda. Anodna oksidacija cijanida zavisi od gustine struje, sastava rastvora, radne temperature itd., a najviše od elektrodnog materijala. Cijanidi su veoma reaktivna jedinjenja koja u obliku cijanovodonika (HCN) predstavljaju izuzetno smrtonosan gas u vlažnim i kiselim uslovima. Pored toga, velika količina cijanida se koristi u rudarstvu, metalo-prerađivačkoj i elektronskoj industriji. Budući da su cijanidi vrlo reaktivani, lako se vežu za metal kao ligand u obliku kompleksa različite stabilnosti i toksičnosti. Budući da ta jedinjenja mogu izazvati veliku štetu za ljude i organizme ako dođu u zemljište i podzemne vode, otpad koji sadrži cijanide treba tretirati vrlo pažljivo za to pogodnim metodama.
ANTIOKSIDATIVNA AKTIVNOST BILJAKA IZ FAMILIJE POLYGONACEAE
Authors: Žabić Mirjana
Published: April 2019

Prirodni antioksidansi su predmet intenzivnog izučavanja zbog njihove sposobnosti da gase slobodne radikale koji se smatraju odgovornim za razvoj degenerativnih bolesti. Istraživanja su naročito fokusirana na biljke koje se tradicionalno koriste u narodnoj medicini podneblja u kojem rastu. Ekstrakcija aktivnih materija se vrši korištenjem raznih rastvarača, a njihov antioksidativni potencijal se mjeri različitim metodama, tako da rezultate njihove primjene često nije moguće upoređivati. Ipak, povremeno je radi preglednosti i izbjegavanja nepotrebnog ponavljanja neophodno sistematizovati saznanja iz ove oblasti. U ovom radu je dat pregled literature antioksidativnog djelovanja rodova Polygonum, Rumex, Fagopyrum, Reynoutria, Fallopia i Rheum iz familije Polygonaceae. Osim porijekla biljne vrste i načina pripreme uzorka, navedeni su rastvarači pomoću kojih je izvedena ekstrakcija, testovi koji su korišteni za određivanje antioksidativne aktivnosti, kao i za određivanja sadržaja jedinjenja koji su nosioci antioksidativnog djelovanja.
CHEMOMETRIC APPROACH TO DETERMINATION OF THE AUTHENTICITY OF DIFFERENT TYPES OF SERBIAN AND MACEDONIAN BRANDY
Authors: Podunavac-Kuzmаnоvić Sanja , Јеvrić Lidiја , Kоvаčеvić Strаhinjа , Маrоšаnоvić Bilјаnа , Lојоvić Маја
Published: April 2019

The isotope ratio mass spectrometry (IRMS) was used to determine the value of the stable isotope carbon (13C/12C), hydrogen (2H/1H) and oxygen (18O/16O) in the molecule of ethanol, produced by alcoholic fermentation of fresh fruit (apples, pears, plums and grapes) from the Republic of Serbia and Macedonia, with and without the addition of sugar from sugar beet. IRMS analysis of alcohols with known botanical and geographical origins enabled the creation of authentic database for Serbian and Macedonian brandy. Regression analysis has been shown as very effective in prediction of the amount of added sugar beet in fruit brandy based on δD values. Statistical data analysis was performed by comparing stable isotope values for different types of brandies. 18O/16O ratio values proved to be very useful in determination of the geographical origin.
TREND RAZVOJA PRIMENE SUPERKRITIČNIH FLUIDA U INDUSTRIJI
Authors: Micic Vladan , Yusup Suzana , Begić Sabina , Dugić Pero , Petrović Zoran , Chan Yi Herng
Published: April 2019

Superkritični fluidi imaju veoma široku mogućnost primene u raznim oblastima. Koriste se u energetskim procesima, kao reakcioni rastvarači, promotori prenosa mase i toplote, separacioni agensi i radni fluidi u procesima sa biogorivom. Iako je ugljen-dioksid još uvek jedan od najčešće korišćenih superkritičnih fluida, propan i fluorovano-hlorovani fluidi se takođe koriste. Postoje brojni slučajevi gde su se kao superkritični fluidi koristili metanol, smeša metanola i sirćetne kiseline, metil – acetat, dimetilkarbonat. Procesi dekofeinizacije čaja i kafe, ekstrakcije hmelja i uklanjanja pesticida iz pirinča primenom superkritičnih fluida zastupljeni su već duže vremena na industrijskom nivou. Glavni cilj primene superkritičnih fluida je još uvek ekstrakcija prirodnih proizvoda radi dobijanja sastojaka hrane, nutraceutikalija i fitofarmaceutikalija. Superkritični procesi su ispitivani i radi dekontaminacije zemljišta, uklanjanja zaostalih rastvarača iz farmaceutskih proizvoda, ekstrakcije zapaljivih jedinjenja iz elektronskog otpada. Povećan je i interes za impregnaciju zasnovanu na primeni superkritičnih fluida kao i korišćenje superkritičnih fluida za bojenje vlakana i tekstila. Dobijanje finih čestica mikronske i submikronske veličine uglavnom za farmaceutske proizvode je još jedna u nizu primena superkritičnih fluida. Na ovaj način se mogu dobiti novi proizvodi koje je nemoguće dobiti klasičnim postupcima. Tehnologija superkritičnih fluida i danas se suočava sa veoma rasprostranjenim mišljenjem da su ovi procesi veoma skupi zbog velikih investicionih ulaganja i da su usled toga ograničeni isključivo na dobijanje izuzetno vrednih proizvoda. Procena troškova za postrojenja različitih veličina i za različite primene je takođe analizirana u okviru rada.
FUNKCIONALNE OSOBINE HLEBA OBOGAĆENOG MODIFIKOVANIM VLAKNIMA
Authors: Filipović Jelena , Filipović Vladimir , Košutić Milenko
Published: April 2019

U razvijenijim zemljama hleb sa visokim sadrţajem prehrambenih vlakana se nalazi na trţištu i sve je većeinteresovanje proizvoĊaĉa za plasiranjem ovakvih proizvoda. Svakim danom povećava se i broj potrošaĉazainteresovanih za konzumiranje hleba obogaćenog vlaknima. Za izradu hleba sa povećanim i visokim sadrţajemvlakana, korišćena su hemijski modifikovana prehrambena vlakna iz ekstrahovanih rezanaca šećerne repe, usitnjena ifrakcionisana. Uticaj vlakana na tehnološke parametre proizvodnje hleba praćen je promenom reoloških i pecivnihosobina testa. Razliĉit udeo vlakana (0%, 5%, 10% i 15%) dodavan je u osnovne sirovine za izradu testa kao zamenaza deo brašna i zapaţeno je da vlakna u testu negativno utiĉu na formiranje glutenskog matriksa, tako da je biloneophodno dodavati vitalni gluten za ojaĉavanje glutenske strukture. Pri istoj koliĉini vode dodate za zames testa, kaoi u testu bez dodataka, modifikovana vlakna utiĉu na povećanje parametara: konzistencije testa u 5. minutu,maksimalne konzistencije i vremena potrebnog za postizanje maksimalne konzistencije. Pravilnom korekcijomsirovinskog sastava i tehnoloških parametara proizvodnje, moţe se dobiti hleb sa 10 i 15% modifikovanih vlakana izšećerne repe koja ne sadrţe fitinsku kiselinu, po senzornim osobinama sliĉan je belom hlebu na koga su potrošaĉinavikli. Hleb sa vlaknima, ima promenjen nutritivni sastav i smanjenu energetsku vrednost, odnosno ima sve osobinefunkcionalnog proizvoda.
SPELT PASTA ENRICHED WITH ω-3 FATTY ACIDS
Authors: Filipović Jelena , Filipović Vladimir , Košutić Milenko
Published: April 2019

In this paper the quality of spelt pasta with the addition of ω-3 fatty acid, which is positively contributing to thefunctional and technological changes of the product is investigated.ω-3 fatty acids are added in the quantity of 0%,0.2%, 0.4% and 0.6% based on farina. Concerning pasta quality addition of ω-3 fatty acids is related to increasedcooking time and cooking loss, as well as reduced pasta stickiness. Gas chromatography with mass spectrometry wasused for carrying out a quantitative analysis of the liposoluble pasta extract. Pasta with 0.6% ω-3 fatty acids contains0.6048 g /100 fatty acids, which positively contributes to ω-6/ω-3 fatty acid ratio in daily meal, thus meeting valuesrecommended by nutritionists. This type of pasta is a new product with good technological quality, improved fattyacids profile and sensory characteristics with consumer acceptability range.
Sinteza i karakterizacija poli(urea-siloksana) i poli(uretan-urea-siloksana) na bazi izoforon diizocijanata
Authors: Balaban Milica , Bolka Silvester , Antić Vesna
Published: April 2019

U okviru ovog rada sintetisani su poliurea (PUS) i poli(uretan-urea) (PUUS)kopolimeri polazeći od aminopropil-terminiranih poli(dimetilsiloksanskih) mekihsegmenata različite mase (PDMS, Mn=1000 g/mol i 3200 g/mol) i izoforon diizocijanata(IPDI), dok je kao produživač lanca korišćen 1,4-budandiol (BD). Kopolimeri susintetisani reakcijom jedno- ili dvostepene poliadicije u rastvoru u prisustvu kalajoktoatakao katalizatora. Molski odnos reaktanata za sintezu PUS kopolimeraiznosio je 1:1,1 (PDMS:IPDI), a za sintezu PUUS koplimera 1:2,1:1 (PDMS:IPDI:BD),dok su kao reakcioni rastvarač korišćene različite smješe tetrahidrofurana (THF) iN-metilpirolidona (NMP). Struktura i sastav sintetisanih kopolimera potvrđene su 1HNMR i FTIR spektroskopijom. Reološka svojstva sintetisanih PUS i PUUS kopolimeraispitana su dinamičko-mehaničkom analizom (DMA) i pokazala su izrazitu zavisnost odprirode i sadržaja tvrdih segmenata, kao i od dužine fleksibilnih siloksanskih segmenatau ispitivanim uzorcima.
Nutritivni kvalitet komercijalnih mješavina Arabika i Robusta kafe
Authors: Odzakovic Bozana , Džinić Natalija , Kravić Snežana , Jokanović Marija , Grujić Slavica
Published: April 2019

Napitak crne kafe tradicionalno se konzumira i pripema od pržene, mljevene kafedostupne na tržištu, a koja se najčešće sastoji od mješavine Arabika i Robusta kafe. Ciljovog rada je da se utvrdi i uporedi nutritivni kvalitet komercijalnih mješavina Arabikai Robusta kafe. U odabranim uzorcima kafe, određen je osnovni hemijski sastav isadržaj specifičnih hemijskih komponenti: kofeina, hlorogenske kiseline i masnihkiselina. Ispitana su i fizička svojstva uzoraka, vrijednost pH, aktivnost vode (aw) iboja (CIE-Lab). Na osnovu rezultata hemijske analize ustanovljeno je da uzorci kafeimaju kvalitet u skladu sa propisanim. Razlike u sadržaju ukupnih rastvorljivih materija,sadržaju proteina i sadržaju slobodne masti bile su statistički značajne (P<0,05)između svih analiziranih uzoraka. Veći sadržaj kofeina (2,18%) i hlorogenske kiseline(4,47%) u jednom od ispitivanih uzoraka, može ukazivati na veći procenat Robustakafe u datoj mješavini. U uzorcima kafe identifikovane su zasićene masne kiseline,palmitinska, stearinska, arahidinska i beheninska i nezasićene masne kiseline oleinska,linolna i linolenska. Ukupni sadržaj nezasićenih masnih kiselina je u svim uzorcima većiu odnosu na ukupni sadržaj zasićenih masnih kiselina, a najveći sadržaj ima linolnaesencijalna masna kiselina (~48,58%). Na osnovu rezultata i utvrđenog nutritivnogkvaliteta komercijalnih mješavina Arabika i Robusta kafe, može se zaključiti da seumjerenim konzumiranjem napitka kafe može doprinijeti dnevnom unosu nutritivnovrijednih i biološko aktivnih jedinjenja.