bluuebunny/crossref_metadata_2025 huggingface dataset:
Carta do editor: o Brasil e a OCDE na Revista Tempo do Mundo
Authors: Barros Pedro Silva
Published: May 2021

A Revista Tempo do Mundo tem como foco principal a economia política e as relações internacionais, abordando diversos debates acadêmicos e políticos relacionados a esses temas. Sua abordagem é plural, explorando dimensões essenciais do desenvolvimento, como questões econômicas, políticas, sociais e de sustentabilidade. A revista busca contribuir para o fortalecimento do diálogo entre acadêmicos e formuladores de políticas públicas, oferecendo um espaço para o intercâmbio de ideias e conhecimentos que possam apoiar a elaboração de políticas públicas em prol do desenvolvimento do país. O número 25 da revista, com o tema "O Brasil na OCDE", atende plenamente aos objetivos institucionais, abordando o processo de adesão do Brasil à Organização para a Cooperação e Desenvolvimento Econômico (OCDE). Além disso, a revista promove eventos de lançamento, como webinars, que contam com a participação de representantes governamentais e acadêmicos, destacando a relevância do tema para o debate público e para a agenda do governo federal. A revista também planeja lançar outros números com temas importantes, como "Políticas Públicas Comparadas para a Retomada pós-Covid-19" e "Os Desafios da Amazônia". Com uma abordagem diversificada e um compromisso com a qualidade acadêmica, a revista Tempo do Mundo busca se consolidar como uma plataforma de discussão e reflexão sobre temas cruciais para o desenvolvimento e a inserção internacional do Brasil.
An Asymmetric Dust Ring around a Very Low Mass Star ZZ Tau IRS
Authors: Hashimoto Jun , Dong Ruobing , Muto Takayuki
Published: May 2021

We present Atacama Large Millimeter/submillimeter Array (ALMA) gas and dust observations at band 7 (339 GHz: 0.89 mm) of the protoplanetary disk around a very low mass star ZZ Tau IRS with a spatial resolution of 025. The 12CO J = 3 → 2 position–velocity diagram suggests a dynamical mass of ZZ Tau IRS of ∼0.1–0.3 M
☉. The disk has a total flux density of 273.9 mJy, corresponding to an estimated mass of 24–50 M
⊕ in dust. The dust emission map shows a ring at r = 58 au and an azimuthal asymmetry at r = 45 au with a position angle of 135°. The properties of the asymmetry, including radial width, aspect ratio, contrast, and contribution to the total flux, were found to be similar to the asymmetries around intermediate mass stars (∼2 M
☉) such as MWC 758 and IRS 48. This implies that the asymmetry in the ZZ Tau IRS disk shares a similar origin with others, despite the star being ∼10 times less massive. Our observations also suggest that the inner and outer parts of the disk may be misaligned. Overall, the ZZ Tau IRS disk shows evidence of giant planet formation on a ∼10 au scale at a few megayears. If confirmed, it will challenge existing core accretion models in which such planets have been predicted to be extremely hard to form around very low mass stars.
The Thermal Reprocessing of Reflected Radiation in the AGN Accretion Disk
Authors: Zhong Xiaogu , Wang Jiancheng
Published: May 2021

We present a reflected reprocessing model to study the thermal lag–wavelength relationship in the AGN accretion disk. The main radiation produced from the corona assumed with the lamppost geometry on the axis of the black hole irradiates the accretion disk to affect the temperature structure via reflection processes. Considering the thermal emission of the disk responded to coronal irradiation, we obtain the lag–wavelength relationship of the disk emission by calculating the response function. We then fit the observed data of four Seyfert 1–1.5 galaxies, NGC4151 , Mrk509, NGC5548, and NGC4593, to test the reflected reprocessing model compared with the X-ray spectrum fitting, and the main results present as follows: (I) The actual geometry of the disk corona is more complex than the lamppost. (II) The option of the reference band is sensitive to fitting the observed time lags. (III) The intrinsic bolometric luminosity is larger than the observed luminosity.
Puffed-up Edges of Planet-opened Gaps in Protoplanetary Disks. I. Hydrodynamic Simulations
Authors: Bi 毕 Jiaqing 嘉擎 , Lin 林 Min-Kai 明楷 , Dong 董 Ruobing 若冰
Published: May 2021

Dust gaps and rings appear ubiquitous in bright protoplanetary disks. Disk–planet interaction with dust trapping at the edges of planet-induced gaps is one plausible explanation. However, the sharpness of some observed dust rings indicate that sub-millimeter-sized dust grains have settled to a thin layer in some systems. We test whether or not such dust around gas gaps opened by planets can remain settled by performing three-dimensional, dust-plus-gas simulations of protoplanetary disks with an embedded planet. We find planets massive enough to open gas gaps stir small, sub-millimeter-sized dust grains to high disk elevations at the gap edges, where the dust scale height can reach ∼70% of the gas scale height. We attribute this dust “puff up” to the planet-induced meridional gas flows previously identified by Fung & Chiang and others. We thus emphasize the importance of explicit 3D simulations to obtain the vertical distribution of sub-millimeter-sized grains around gas gaps opened by massive planets. We caution that the gas-gap-opening planet interpretation of well-defined dust rings is only self-consistent with large grains exceeding millimeter size.
The GALAH Survey: No Chemical Evidence of an Extragalactic Origin for the Nyx Stream
Authors: Zucker Daniel B. , Simpson Jeffrey D. , Martell Sarah L. , Lewis Geraint F. , Casey Andrew R. , Ting 丁 Yuan-Sen 源森 , Horner Jonathan , Nordlander Thomas , Wyse Rosemary F. G. , Zwitter Tomaž , Bland-Hawthorn Joss , Buder Sven , Asplund Martin , De Silva Gayandhi M. , D’Orazi Valentina , Freeman Ken C. , Hayden Michael R. , Kos Janez , Lin Jane , Lind Karin , Schlesinger Katharine J. , Sharma Sanjib , Stello Dennis
Published: May 2021

The results from the ESA Gaia astrometric mission and deep photometric surveys have revolutionized our knowledge of the Milky Way. There are many ongoing efforts to search these data for stellar substructure to find evidence of individual accretion events that built up the Milky Way and its halo. One of these newly identified features, called Nyx, was announced as an accreted stellar stream traveling in the plane of the disk. Using a combination of elemental abundances and stellar parameters from the GALAH and Apache Point Observatory Galactic Evolution Experiment (APOGEE) surveys, we find that the abundances of the highest likelihood Nyx members are entirely consistent with membership of the thick disk, and inconsistent with a dwarf galaxy origin. We conclude that the postulated Nyx stream is most probably a high-velocity component of the Milky Way’s thick disk. With the growing availability of large data sets including kinematics, stellar parameters, and detailed abundances, the probability of detecting chance associations increases, and hence new searches for substructure require confirmation across as many data dimensions as possible.
The In Situ Exploration of a Relict Ocean World: An Assessment of Potential Landing and Sampling Sites for a Future Mission to the Surface of Ceres
Authors: Scully Jennifer E. C. , Baker Samantha R. , Castillo-Rogez Julie C. , Buczkowski Debra L.
Published: May 2021

The Dawn orbiter’s exploration of Ceres, the most water-rich body in the inner solar system after Earth, revealed the dwarf planet to be a relict ocean world of great interest to the astrobiology and ocean worlds communities. Evidence for an early global subsurface ocean is preserved in Ceres’ surface minerals. While most of the subsurface ocean froze billions of years ago, its liquid (preserved in a deep brine reservoir) and solid remnants are responsible for spectacular surface features such as the faculae in the Occator crater, Ahuna Mons, and Haulani crater. Therefore, the next step in Ceres exploration is an in situ mission to the surface, with these three features being among the most scientifically compelling targets. Here we demonstrate the process of identifying potential landing/sampling sites. Using the highest resolution data obtained by Dawn (up to ∼5 m/pixel in Occator and up to ∼35 m/pixel elsewhere), we identify safe and scientifically compelling potential landing/sampling sites in these three regions. For future landing/sample return, higher spatial resolution data (a few decimeters per pixel to ∼1 m/pixel) than are currently available are needed to identify hazards on the scale of a ∼1–5 m lander. Such data could be obtained in an orbital reconnaissance phase prior to landing/sampling. Orbital reconnaissance, in combination with terrain relative navigation/hazard avoidance, and the ability to land within a ≦100 m diameter circle (>800,000 of which fit within Occator), makes it highly likely that safe and scientifically compelling landing/sampling sites could be reached by a future in situ mission.
Evaluation of Antioxidant Activity of Botto-Botto Leaf Fraction (Chromolaena Odorata L.) Using DPPH and ABTS Methods
Authors: Tahir Karlina Amir , Miskad Upik A. , Djawad Khairuddin , Djide Sartini , Khaerani Khaerani , Indrisari Maulita
Published: May 2021

BACKGROUND: Antioxidants are substances that can inhibit the oxidation process, so that they have a protective effect on cells from the dangers of free radicals. One of the plants that has activity as natural antioxidants is Botto-Botto leaves (Chromolaena odorata L.).
AIM: This study aims to determine the antioxidant activity of the Botto-Botto leaf fraction using the DPPH and ABTS methods.
METHODS: The leaves of Botto-Botto (Chromolaena odorata L.) obtained from Takalar District, South Sulawesi are sorted, dried and pollinated. The powder was immersed in 70% ethanol solvent and sonicated. Furthermore, the extraction was carried out by maceration method with 70% ethanol solvent and fractionated using water, n-hexane, and n-butanol as solvents and dried. The fractionation results were continued for antioxidant testing using the DPPH and ABTS methods.
RESULTS: The n-butanol fraction of Botto-Botto leaves had the highest antioxidant activity, namely the strong active category. In the DPPH and ABTS methods, the n-butanol fraction has IC50 values of 33.535 μg / mL and 60.885 μg / mL, respectively.
CONCLUSION: The DPPH and ABTS methods, the n-butanol fraction of botto-botto leaves have strong antioxidant activity compared to other fractions, namely the water fraction and the n-hexane fraction.
Diversity of Plectosphaerella within aquatic plants from southwest China, with P. endophytica and P. sichuanensis spp. nov.
Authors: Yang Xiao Qian , Ma Shi Yun , Peng Ze Xiang , Wang Zhong Qiao , Qiao Min , Yu Zefen
Published: May 2021

Members of Plectosphaerella inhabit different substrates, including plants, soil and insects, and most species are pathogens causing large losses in agriculture. During a survey of endophytic fungi in aquatic plants in southwest China, 112 strains of Plectosphaerella were isolated, representing two new species, P. endophyticasp. nov. and P. sichuanensissp. nov., as well as two known species, P. cucumerina and P. pauciseptata. The novel taxa are described and illustrated here using combined morphological and multi-locus phylogenetic (LSU-ITS-TEF-1α-TUB2) analyses. Our result revealed Plectosphaerella species inhabiting within aquatic plants in southwest China, and the separation frequency of each species was presented.
Floristic composition and community structure along the elevational gradient of Balinsasayao Twin Lakes Natural Park in Negros Oriental, Philippines
Authors: Aureo Wilbert , Reyes Jr. Tomas , Mutia Francis Carlo , Tandang Danilo , Jose Reizl
Published: May 2021

Balinsasayao Twin Lakes Natural Park (BTLNP) is one of the protected areas on the Island of Negros Oriental which is enormously rich in biodiversity due to different Lowland types formed along its elevation gradient. This study was conducted to better understand the composition and diversity of plant species in the natural park to improve conservation and management efforts of these remaining forests which are currently under threat from eco-tourism and other anthropomorphic influences. Within the 18 randomly distributed nested plots, a total of 351 species of plants were recorded. Of these, 183 species were trees, 54 herbs, 51 shrubs, 41 pteridophytes and 22 vines. The result of hierarchical cluster analysis showed differences in plant composition along the elevation gradient. There were 30 (9%) threatened species (vulnerable, endangered and critically endangered) and most of which were found in the submontane Lowland. Furthermore, the species diversity increases from lowland to sub-montane and eventually decreases towards montane Lowland. These results not only indicate the importance of BTLNP, but also highlights the submontane as a special area of concern due to the higher concentration of threatened and endemic species.
Two new bamboo-feeding species of the genus Kirbyana Distant, 1906 from China (Hemiptera, Fulgoromorpha, Cixiidae)
Authors: Zhi Yan , Yang Lin , Chen Xiang-Sheng
Published: May 2021

Two new bamboo-feeding species of the cixiid planthopper genusKirbyanaDistant, 1906 (Hemiptera: Fulgoromorpha: Cixiidae: Eucarpiini),K. aspinaZhi & Chen,sp. nov.andK. furcataZhi & Chen,sp. nov., are described and illustrated from southern China. A key to all known species and a map of their geographic distributions are provided.
Posterior Chamber Phakic Intraocular Lens Implantation for Refractive Correction in Corneal Ectatic Disorders: A Review
Authors: Kalra Nidhi , Asif Mohamed Ibrahime , Bafna Rahul Kumar , Sharma Namrata , Sinha Rajesh
Published: May 2021

PURPOSE:

To summarize the indications and outcomes of posterior chamber phakic intraocular lens (PIOL) implantation in corneal ectasias including keratoconus, pellucid marginal degeneration (PMD), post-refractive surgery, and post-keratoplasty ectasias.

METHODS:

A review of the literature was conducted using the relevant keywords from various databases up to August 15, 2020. All pertinent studies were reviewed, and the relevant articles were studied in detail for efficacy, stability, predictability, and safety outcomes. In addition, visual quality, corneal biomechanical outcomes, complications, the role of posterior chamber PIOL in combination treatment, and comparison of posterior chamber PIOL with other PIOLs for ectasias were also evaluated.

RESULTS:

A total of 30 relevant studies (13 prospective, 13 retrospective, 4 case reports) on the subject were studied and summarized. All studies showed a favorable refractive outcome. Quality of vision remained unaffected and no significant complications were reported in any of the studies.

CONCLUSIONS:

Posterior chamber PIOLs represent a viable option in the treatment of mild to moderate and stable corneal ectasia in patients with contact lens intolerance who have low irregular astigmatism, a clear central cornea, and good preoperative corrected distance visual acuity.

[
J Refract Surg
. 2021;37(5):351–359.]
The Relationship Between the Change of Intraocular Lens Position and Capsular Bend After Cataract Surgery
Authors: Chang Pingjun , Li Xiuyuan , Chen Dongjie , Xu Zhizi , Ding Xixia , Zhao Yun-e
Published: May 2021

PURPOSE:

To explore the relationship between the change in intraocular lens (IOL) position and capsular bend after cataract surgery.

METHODS:

Patients underwent phacoemulsification and IOL implantation (Alcon Laboratories, Inc). Patients were divided into two groups based on preoperative axial length: long axial length group (axial length ⩾ 26 mm) and normal axial length group (axial length > 22 but < 26 mm). Swept-source optical coherence tomography was performed at 1 day, 1 week, 1 month, and 3 months after mydriasis to obtain postoperative aqueous depth (PAD) and capsular bend index (CBI). The relationship between CBI and PAD changes was analyzed.

RESULTS:

Eighty patients (80 eyes) were included in the study. PAD decreased gradually from 1 day to 1 week and increased from 1 week to 3 months. Mean CBI was moderately positively correlated with PAD changes (
r
= 0.586,
P
< .001). The IOL moved forward gradually when the CBI was less than 2.30 and the IOL gradually moved backward when the CBI was 2.30 or greater. The root mean square of the change in PAD was smaller in the long axial length group (0.08 ± 0.04 mm) than in the normal axial length group (0.09 ± 0.05 mm) during the 3 months after surgery (
P
= .036).

CONCLUSIONS:

The position of the IOL was almost stable 1 month after operation, and postoperative capsule adhesion mainly occurred within 1 month. The change in PAD was related to capsule adhesion. The postoperative position of the IOL was relatively stable and capsular bend was relatively slow for the long axial length group over 3 months.

[
J Refract Surg
. 2021;37(5):324–330.]
Predictability of Refractive Outcome of a Small-Aperture Intraocular Lens in Eyes With Irregular Corneal Astigmatism
Authors: Langer Julian , Shajari Mehdi , Kreutzer Thomas , Priglinger Siegfried , Mayer Wolfgang J. , Mackert Marc J.
Published: May 2021

PURPOSE:

To compare different new-generation biometric formulas and ray-tracing for small-aperture intraocular lens (IOL) (IC-8; Acufocus, Inc) implantation in patients undergoing cataract and refractive lens exchange surgery with highly irregular corneas.

METHODS:

This monocenter study included 17 eyes of 17 patients with highly irregular corneas of different genesis. Biometric and topographic corneal data were assessed using the IOLMaster 700 (Carl Zeiss Meditec) and Pentacam (Oculus Optkigeräte GmbH). Prediction and absolute error were compared after 3 months based on manifest refraction. Furthermore, change of total corneal refractive power in different corneal pathologies was also evaluated. For IOL power calculation, three fourth-generation IOL formulas were compared (Haigis, SRK-T, and Barrett Universal II). The dataset was then checked against ray-tracing and analyzed to improve prediction error in these highly irregular corneas.

RESULTS:

All patients showed an improvement in visual acuity postoperatively with a mean spherical equivalent of −1.22 ± 0.49 diopters (D). Overall comparison of the three formulas showed the Haigis formula to be superior in terms of the smallest deviation of predictive and absolute error. IOL calculations with ray-tracing were possible in all eyes, but showed inaccurate results with keratometric values of 48.00 D and greater.

CONCLUSIONS:

The IC-8 IOL is well suited for patients with lens exchange in highly irregular corneas. The Haigis formula seemed to be the most accurate in the patient group. Ray-tracing confirmed the results of biometric formulas up to a keratometric value of 48.00 D and should be compared with standard biometric formulas to address corneal irregularities and to minimize refractive surprises after surgery. A comparison with ray-tracing in eyes with a keratometric value of greater than 48.00 D should not be considered due to the inaccurate results.

[
J Refract Surg
. 2021;37(5):312–317.]
Global dynamics analysis of a time-delayed dynamic model of Kawasaki disease pathogenesis
Authors: Guo Ke , Ma Wanbiao , Qiang Rong
Published: May 2021

Kawasaki disease (KD) is an acute febrile vasculitis that occurs predominantly in infants and young children. With coronary artery abnormalities (CAAs) as its most serious complications, KD has become the leading cause of acquired heart disease in developed countries. Based on some new biological findings, we propose a time-delayed dynamic model of KD pathogenesis. This model exhibits forward\begin{document}$ / $\end{document}backward bifurcation. By analyzing the characteristic equations, we completely investigate the local stability of the inflammatory factors-free equilibrium and the inflammatory factors-existent equilibria. Our results show that the time delay does not affect the local stability of the inflammatory factors-free equilibrium. However, the time delay as the bifurcation parameter may change the local stability of the inflammatory factors-existent equilibrium, and stability switches as well as Hopf bifurcation may occur within certain parameter ranges. Further, by skillfully constructing Lyapunov functionals and combining Barbalat's lemma and Lyapunov-LaSalle invariance principle, we establish some sufficient conditions for the global stability of the inflammatory factors-free equilibrium and the inflammatory factors-existent equilibrium. Moreover, it is shown that the model is uniformly persistent if the basic reproduction number is greater than one, and some explicit analytic expressions of eventual lower bounds of the solutions of the model are given by analyzing the properties of the solutions and the range of time delay very precisely. Finally, some numerical simulations are carried out to illustrate the theoretical results.
Vegetation and flora of the river-basin of the Gačnik stream (Vojsko, Spodnja Trebuša) – a contribution for its nature protection evaluation / Rastje in rastlinstvo povodja Gačnika na Vojskem in v Trebuši – prispevek za njegovo naravovarstveno vrednotenje
Authors: Dakskobler Igor , Čar Jože , Rudolf Anka , Terpin Rafael , Vreš Branko
Published: May 2021

We have summarized results of our research of vegetation and flora in the river-basin of the Gačnik (Vojsko, Dolenja Trebuša) in western Slovenia. We enumerate most frequent and characteristic plant communities, which belong to seven habitat types of European conservation importance. In their stands grow two Natura 2000 species (Primula carniolica, Cypripedium calceolus) and almost 60 vascular plant species, which are protected and (or) on the red list. Among communities and plants are the most threatened fens and moist grasslands and their characteristic species: Drosera rotundifolia, Dactylorhiza lapponicasubsp. rhaetica, D. traunsteineri, Eleocharis quinqueflora,Eriophorum angustifolium, E. latifolium, Pinguicula vulgaris and Trichophorum alpinum.

Key words: vegetation, flora, wetlands, fens, Natura 2000, Slovenia

 

Izvleček

V članku smo povzeli rezultate naših raziskav rastja in rastlinstva v povodja Gačnika na Vojskem in v Trebuši v zahodni Sloveniji. Naštevamo najbolj pogoste in najbolj značilne rastlinske združbe, zavarovane in redke rastline in naravovarstveno vredne habitatne tipe. Slednjih je vsaj sedem. V njihovih združbah uspevata dve Natura 2000 vrsti (Primula carniolica, Cypripedium calceolus) in skoraj 60 zavarovanih in (ali) redkih cevnic (rdeči seznam). Med združbami so najbolj ogrožena mokrišča (nizka barja in mokrotni travniki) in njihove značilne vrste: Drosera rotundifolia, Dactylorhiza lapponicasubsp. rhaetica, D. traunsteineri, Eleocharis quin­queflora,Eriophorum angustifolium, E. latifolium, Pinguicula vulgaris in Trichophorum alpinum.

Ključne besede: vegetacija, flora, mokrišča, nizka barja, Natura 2000, Slovenija
Stratégie-cadre d’éducation relative à l’environnement auprès des adultes pour la construction de systèmes agroalimentaires socialement équitables et écologiquement responsables
Authors: Bisquert i Pérez Kylyan Marc , Agundez-Rodriguez Adolfo
Published: May 2021

L’évolution des systèmes agroalimentaires a été déterminant pour le développement des sociétés humaines. Ainsi, de nos jours, le système hégémonique en place induit des modes de production, de distribution et de consommation alimentaires qui participent de façon majeure à la crise socio-environnementale. Dans un tel contexte, un changement de paradigme agroalimentaire s’impose afin de promouvoir les transformations nécessaires à la transition écosociale. La création d’espaces de réflexion collective et de co-construction de systèmes agroalimentaires alternatifs apparaît comme un contexte privilégié pour contribuer à un tel changement. À cet égard, l’éducation peut jouer un rôle de premier ordre : elle peut stimuler la mise en place de tels espaces, accompagner l’apprentissage qui s’y réalise et inviter à l’analyse, à la discussion et à la diffusion d’initiatives porteuses. Cet article propose en ce sens des éléments essentiels à l’élaboration d’une stratégie-cadre d’action socio-éducative auprès des adultes, inspirée du courant écologiste de l’éducation relative à l’environnement et basée sur les principes de l’agroécologie.
Le Hack écologique au musée : une stratégie d’éducation relative à l’environnement auprès des adultes
Authors: Clover Darlene , Villemagne Carine
Published: May 2021

L’art et la créativité qui s’y rattache sont depuis longtemps au cœur des pratiques d’éducation relative à l’environnement menées avec des adultes. Dans cette présentation, je commencerai par jeter les bases de l’éducation relative à l’environnement (ERE) auprès des adultes, puis je partagerai divers types d’initiatives artistiques qui s’y rattachent ainsi que des pratiques communautaires. Je poursuivrai avec une discussion sur une toute nouvelle pratique d’ERE auprès des adultes, soit le Hack écologique au musée. Ce dernier est conçu comme une stratégie éducative permettant d’analyser de manière critique les représentations de la nature et de la société qui sont véhiculées dans les institutions artistiques et culturelles et qui façonnent activement notre regard, pour ensuite être en mesure d’exercer un pouvoir sur la façon dont nous comprenons nos relations à l’environnement, passées et actuelles.
De l’intérêt au savoir : le processus de l’apprentissage chez Dewey et Bachelard
Authors: Charbonnier Sébastien
Published: May 2021

Il s’agit, dans cet article, de rapprocher les pensées, a priori opposées, de Dewey et Bachelard concernant le rôle et le fonctionnement de l’apprentissage. Les thèmes abordés correspondent à l’ordre génétique de production de la connaissance. Se pose d’abord le problème de la dialectique entre l’intérêt et l’effort. Comment susciter le désir d’apprendre chez les élèves ? En même temps, comment gérer les impulsions premières qui sont autant d’obstacles à la connaissance ? Les deux auteurs partagent une même défiance vis-à-vis de la paresse intellectuelle des explications du sens commun, mais savent prendre en compte la nécessité d’« intéresser » les élèves pour autoriser un effort qui ne soit pas une souffrance. Une fois l’amorce du processus d’apprentissage établie, se pose le problème de la nature du savoir offert à l’apprentissage. Celui-ci n’est plus contemplation passive mais expérimentation active. La connaissance n’est plus un état, elle est un devenir – elle se situe « dans » le passage. Il s’agit donc de partir de ce que les élèves savent pour travailler dessus. L’épistémologie suit la psychologie : de même qu’il faut partir des intérêts actuels des élèves pour les réformer, de même il faut partir des connaissances des élèves pour les rectifier. Quelle est alors la conception de la relation enseignante qui découle d’un savoir conçu de cette sorte ? Le cogito se dédouble dans les deux figures du maître et de l’élève, désormais interchangeables alternativement. On ne corrige plus l’élève, on se corrige les uns les autres. Le savoir se construit comme la perspective générale des erreurs rectifiées. Il en résulte une pédagogie relationnelle en un sens non seulement intersubjectif mais transcendantal. Le maître et l’élève sont moins des personnes physiques que des « personnages conceptuels » qui correspondent à des moments de la pensée.
La fonction de l’imaginaire dans la construction de la problématique en recherche doctorale : obstacle et outil
Authors: Xypas Constantin , Hétier Renaud
Published: May 2021

L’imaginaire est ici réévalué, dans la veine bachelardienne, comme source et élan vers le savoir, mais aussi comme obstacle. Il importe cependant de comprendre de quelle façon cet imaginaire est susceptible de configurer notre appréhension du monde, des objets, du réel même. Ceci, notamment dans la situation où sont les jeunes chercheurs en sciences sociales, qui doivent faire à la fois avec la force de leur intuition – du fait de leur « jeunesse » dans la recherche, et avec le rapport impliqué et impliquant qu’ils ont avec leurs objets, qui sont volontiers d’autres sujets, quand il ne s’agit du sujet qu’ils sont pour eux-mêmes. Le travail de catégorisation des structures imaginaires opéré par Gilbert Durand est alors d’un précieux secours. Mais il ne saurait être question de s’arrêter à une description : la recherche exige un déplacement, depuis des positions spontanément militantes et/ou complices, vers un positionnement synthétique, qui soit susceptible de prendre en considération la complexité, les tensions, les contradictions du réel. C’est sur les modalités opératoires d’un accompagnement qui favorise ce déplacement que se termine cette contribution.
Identité professionnelle des formateurs d’enseignants de Lycée Professionnel en IUFM : enjeux et dilemmes à l’heure des réformes
Authors: Perez-Roux Thérèse
Published: May 2021

L’article s’intéresse à l’identité des formateurs d’enseignants de lycée professionnel au moment où se profilent des changements liés à la mise en place d’une formation universitaire de niveau Master. Deux enquêtes qualitatives ont été conduites avec les formateurs d’un même IUFM, à deux ans d’intervalle. Les résultats de 2007 permettent de comprendre la manière dont ces acteurs définissent leur mission, entre culture partagée avec les autres formateurs et spécificités revendiquées. L’enquête de 2009 rend compte d’une évolution. La perspective de réorganisation de la formation génère des incertitudes sur l’avenir. L’étude met en relief des inquiétudes en termes d’intégration et de légitimité. Elle souligne la nécessaire redéfinition des contours de l’activité professionnelle. Des questions de reconnaissance traversent les discours des formateurs, éclairant la place que l’institution accordait jusqu’ici à ces acteurs. Cette place, à renégocier dans un avenir proche, génère des positionnements différents au sein du groupe étudié.
Quels sont les effets de l’éducation artistique ? Étude d’une situation paradoxale
Authors: Ruppin Virginie
Published: May 2021

L’éducation artistique prétend obtenir certains effets sur les individus. Qu’est-ce que le recours aux activités artistiques produit réellement dans l’institution, mais aussi sur les individus qui s’y trouvent, lorsque des artistes interviennent en école élémentaire ? Le cadre théorique de la sociologie de la justification et de la délégation aux objets nous permet d’une part, de mieux cerner quelles sont les attentes explicitées lors des entretiens semi-directifs menés en amont des observations de séances et d’autre part, de mieux analyser les pratiques concrètes des enseignants observées in situ en présence de l’artiste et des élèves. À travers l’exemple d’un projet artistique et culturel en musique mené en classe de CM2, nous avons pu nous rendre compte, contre toute attente, que la mise en place du projet avait tendance à renforcer les règles de conduite. L’enseignant, au lieu de se servir de la musique à l’école pour développer l’expression, la création, l’épanouissement de l’enfant, comme nous révèle le discours, en fait, y voit un moyen de discipliner sa classe.
La pédagogie interculturelle : entre multiculturalisme et universalisme
Authors: Pretceille Martine A.
Published: May 2021

L’auteur se propose de démontrer que la pédagogie interculturelle s’inscrit dans une tension entre une exacerbation des différences et un universalisme malheureusement confondu avec le principe éthique d’universalité. En effet, le traitement de l’hétérogénéité culturelle suppose d’adosser l’analyse et l’action sur une philosophie à la fois morale et pragmatique au sens où il s’agit de chercher à comprendre des pratiques, des discours et des comportements ancrés non pas dans des catégories culturelles distinctes, homogènes et hermétiques les unes aux autres, mais au contraire dans des processus de métissage et de « créolisation ». Apprendre à voir, à écouter, à être attentif à autrui renvoient à l’expérience de l’altérité et non à un apprentissage des cultures. Cette expérience s’acquiert et se travaille. Ainsi, la prise en compte de la culture ne se limite pas à l’introduction d’une variable supplémentaire. Il convient de se détacher de toute conception différencialiste, déterministe et causaliste pour construire un humanisme du divers.
Reprise d’initiative et éducation interculturelle chez les Amérindiens de l’Amazonie brésilienne (Etat d’Amazonas)
Authors: Meunier Olivier
Published: May 2021

La transmission traditionnelle des savoirs dans les sociétés relevant de l’oralité et le modèle occidental de la forme scolaire peuvent apparaître a priori dichotomiques, ce qui a souvent contribué à leur développement juxtaposé et le plus souvent à un processus de domination du second sur les premières. Au Brésil, suite au processus républicain visant à assimiler les populations amérindiennes à la Nation durant les années 1970-1980, ces dernières se sont organisées pour sauvegarder leur territoire et leur identité culturelle, ce qui a donné lieu, à partir des années 1990, à la généralisation d’une éducation scolaire interculturelle dans les territoires indigènes, ouvrant la forme scolaire aux savoirs socioculturels des peuples premiers. En intégrant des savoirs « traditionnels » dans l’enseignement, la forme scolaire a permis à ces enfants éloignés d’une culture scolaire « occidentalisée », de relier les savoirs « communautaires » aux savoirs scolaires. Ce système présente une capacité à considérer la pluralité des différences culturelles. Celle-ci n’est alors pas vécue comme une trace régressive d’inconscient collectif. C’est au contraire la reconnaissance des cultures traditionnelles qui conditionne le désir de connaissances nouvelles et son appropriation, ce qui pourrait être aussi une réponse pour d’autres pays, notamment chez les élèves socialement et culturellement éloignés de la forme scolaire instituée.
Le travail scolaire : définition, histoire et moteu d’un objet d’étude socio-historique
Authors: Sembel Nicolas
Published: May 2021

L’objectif de cet article est de construire le travail scolaire comme objet d’étude socio-historique. Alors que le travail scolaire est souvent perçu comme « ce que demande l’école » aux élèves (efficace, il permet à l’élève de réussir ; inefficace, il le conduit à l’échec), il doit être plutôt défini, d’un point de vue sociologique, comme le rapport des élèves à ce que demande l’école. Le travail scolaire serait alors constitué de tout ce qui est fait par les élèves, plus ou moins en lien avec le cadre et les prescriptions scolaires, et qui relève d’un travail intellectuel. L’approche sociologique met en avant une tension constitutive du travail scolaire ainsi défini, qui critique son histoire institutionnelle pour mettre en avant son histoire « par le bas », par les pratiques réelles des élèves et leurs interactions réelles avec l’institution scolaire, qui s’en trouve elle aussi redéfinie. En replaçant ensuite cette approche sociologique dans une perspective historique, il est possible de formuler une hypothèse socio-historique, selon laquelle le moteur du travail scolaire est un produit de la tension anthropologique, inscrite dans la longue durée, entre l’acteur et le système. L’objet travail scolaire se nourrit de l’opposition entre l’économie de la simplification des apprentissages vers laquelle tend « naturellement » toute institution scolaire, quand les résistances ne sont pas trop fortes ; et l’économie de la subjectivation par le travail vers laquelle tend tout aussi « naturellement » l’élève, quand la sélection scolaire n’est pas trop forte. Le travail scolaire redéfini socio-historiquement se structure autour de l’opposition entre intérêt intellectuel et émulation intellectuelle. Il produit, entre autres, une figure historique inédite : celle d’un travailleur scolaire « hérétique », caractérisé par un rapport particulier d’autonomie à l’institution scolaire, le « désengagement conflictuel » (Eigensinn).
Coopération des enseignants et nouvelles approches de l’organisation du travail dans les établissements scolaires
Authors: Romanato Laëtitia Progin , Thurler Monica Gather
Published: May 2021

Cette contribution vise à mettre en évidence les liens entre des formes de travail scolaire innovantes et des types de relations entre enseignants proches de la coopération professionnelle. Nous cherchons tout d’abord à montrer que l’individualisme enseignant trouve en partie son origine dans les formes d’organisation du travail scolaire associées au fonctionnement de nos systèmes. Nous analysons ensuite les spécificités et obstacles intervenant lors de la mise en œuvre d’une coopération professionnelle que nous considérons comme l’une des conditions indispensables pour que les enseignants puissent concevoir des formes du travail scolaire mieux adaptées au contexte de leur établissement. Nous terminons en présentant la « communauté professionnelle apprenante » au sein de laquelle les pratiques de coopération dépendent de cinq « piliers » se constituant au gré des tentatives que les divers acteurs entreprennent pour développer la qualité de l’enseignement-apprentissage.
Risquer le pédagogique, entre héritage et modernité
Authors: Chalmel Loïc
Published: May 2021

Se défiant des modèles à prétention universelle et revendiquant un indéfectible attachement à une expérience singulière, le « lieu » subjectif des pédagogues, se présente néanmoins comme un riche espace de création intellectuelle en tension dans l’entre-deux théories pratiques. Conservatoire de la mémoire des choix de valeurs effectués par des individus singuliers dans des contextes socio-historiques particuliers, il collationne autant d’alternatives qui pourront faire l’objet d’un examen ultérieur, suggérant des repères pour l’action, pour peu que les « suivants » ne perdent pas la mémoire… L’historien des idées pédagogiques participe à ce devoir de mémoire, remodelant les matériaux du passé sans les reproduire à l’identique. Sortir d’une dynamique de l’oubli nécessite sans doute que certains se coltinent à une réécriture inlassable de l’histoire, entremetteurs d’une culture pédagogique, bien commun de tous ceux qui de près ou de loin s’impliquent aujourd’hui dans l’acte d’éduquer. Retrouver la mémoire pour s’ouvrir des possibles ; éviter de réinventer la roue à chaque génération. Le passage de la pédagogie à l’histoire n’est pas seulement affaire d’épistémologie : écrire l’histoire des idées pédagogiques, c’est à la fois être capable de se projeter dans l’univers de l’autre, solidaire de sa solitude, et, pour comprendre ce qui motive des choix, contraint sa liberté d’action, déconstruire une unité dynamique pour expliciter les articulations entre les différents types de savoirs qui la constitue.
Nanomaterials and Nanocomposites Thermal and Mechanical Properties Modelling
Authors: Kosti Siddhartha
Published: May 2021

This chapter deals with the modelling of nanomaterial and nanocomposite mechanical and thermal properties. Enrichment in the technology requires materials having higher thermal properties or higher structural properties. Nanomaterials and nanocomposites can serve this purpose accurately for aerospace or thermal applications and structural applications respectively. The thermal system requires materials having high thermal conductivity while structural system requires materials having high strength. Selection of the material for particular application is very critical and requires knowledge and experience. Al, Cu, TiO2, Al2O3, etc. are considered for thermal applications while epoxy-glass, FRP, etc. are considered for structural applications. Modelling of these nanomaterials and nanocomposites is done with the help of different mathematical models available in the literature. Results show that addition of the nanoparticle/composite in the base material can enhance the thermal and structural properties. Results also show that amount of weight percentage added also affects the properties.
Synthesis of Epoxy Nanocomposites
Authors: Irzhak Tamara F. , Irzhak Vadim I.
Published: May 2021

The formation processes of epoxy nanocomposites with carbon (nanotubes, graphene, and graphite), metal-containing, and aluminosilicate (montmorillonite and halloysite tubes) fillers are considered. A high reactivity of epoxy groups and a thermodynamic miscibility of epoxy oligomers with many substances make it possible to use diverse curing agents and to accomplish curing reactions under various technological conditions. Epoxy nanocomposites are designed to realize to the same extent the unique functional properties of nanoparticles: electric, magnetic, optical, chemical, and biological. The mutual effect of both a matrix and nanoparticles on the composite formation is discussed.
Synthesis of Magnesium Based Nanophosphors and Nanocomposites by Different Techniques
Authors: Naik Ramachandra , Revathi V.  , Prashantha S. C. , Nagabhushana H.
Published: May 2021

This chapter consists of systematic synthesis of magnesium silicate nanoparticles by solution combustion method using ODH fuel. Compared to other fuels, ODH has the better advantages of obtaining crystalline nanomaterials without post calcinations. By doping different rare earth ions to magnesium silicate, the product can be used for luminescent applications. Synthesis of magnesium ferrite nanoparticle is done using molten salt method followed by the synthesis of polymer composite in the form of fibers by the process of electrospinning.
Methods of Preparation of Nanoparticle Formulations for the Treatment of COPD
Authors: Paul Suprio R. , Nayak Suraj K. , Anis Arfat , Pal Kunal
Published: May 2021

The incidence of chronic obstructive pulmonary disease (COPD) has increased many folds in the last couple of decades. This can be explained by the increased pollution levels and drastic changes in the lifestyle of the people. Taking a note of this, in this review, a conscious attempt was made to understand the physiological changes in the respiratory tract in a COPD patient. Nanoparticulate formulations play an extensive role in the current-day treatment regime of COPD patients. Hence, different methods for developing nanoparticulate formulations for the treatment of COPD are discussed in details.
Properties Enhancement of Polymer/Ceramic Nanocomposites
Authors: Ramdani Noureddine , Azibi Mehdi
Published: May 2021

This chapter reviews the various properties enhancement of polymer/ceramic nanocomposites. Ceramics nanofillers have attracted both academic and industrial interest as they can produce a significant improvement in the properties of polymers even at lower filler loadings. Recently, numerous kinds of polymeric matrices reinforced with ceramic nanoparticles have been reported. The surface-modification of ceramic nanoparticles was reported to provide extra-improvements in the thermal and mechanical properties of these materials. In addition, the type of the used ceramic nanofillers agent determines the final properties of the nanocomposites. Herein, the various effects of adding ceramic nanoparticles on the thermal, electrical, optical, and mechanical properties of polymer/ceramic nanocomposites as well as the reinforcing mechanism are discussed in general along with detailed examples drawn from the scientific literature.
Visible Light Active Nanocomposites for Photocatalytic Applications
Authors: Singh Rohini , Dutta Suman
Published: May 2021

This chapter explores the concept of visible light active nanocomposites for the enhanced photocatalytic hydrogen generation and dye degradation. Since the late 1960s, A. Fujishima has been involved in unfolding the fascinating characteristics of titanium dioxide (TiO2) as semiconductor oxide. The increased growth in population and industrial development has tremendously increased the generation of waste products and consumption of energy worldwide. This situation creates an immense need of clean and sustainable alternative sources of energy. Hydrogen, having a high energy capacity, is considered as a reliable fuel for the future energy requirements. In addition to that, due to the rapid industrialisation, our water is being contaminated with various harmful industrial effluents. This chapter illustrates the significance of visible light nanocomposites for the photocatalytic application of hydrogen generation for future energy security and dye degradation for the effective effluent treatment of textile industries.
Nanoparticles for Degradation of Organic Pollutants
Authors: Aslam Sana , Ahmad Matloob
Published: May 2021

Water pollution is becoming a serious threat to the environment. The access to safe drinking water, especially for the poor, is reaching an alarmingly low level, and the number of people suffering from kidney, stomach, and liver diseases, etc. is increasing every day. Among various pollutants, organic pollutants have major contribution in the contamination of water. These pollutants include toxic dyes, pharmaceutical compounds, industrial chemicals, and organic solvents, etc. Various routes are being employed for the removal/degradation of these pollutants. The use of nanoparticles (i.e., metal nanoparticles, nanocomposites, carbon nanotubes, and graphene oxide-based nanocomposite materials) possesses significant position as photocatalysts. This chapter has a focus on the environment remediation using these nanomaterials and contains the recent work in this field.
Application of Magnetic Nanomaterials for Water Treatment
Authors: Lateef Ambreen , Nazir Rabia
Published: May 2021

The availability of clean drinking water becomes a critical issue for all the people of the world due to a rapid increase in population and industrialization. The water bodies get contaminated due to the discharge of wastewater, that will not only disturb the aquatic life but also badly affect human health. Therefore, different methods are adopted to treat the contaminated water to make it clean and safe for people. In last few years, the nanomaterials have gained much attention for water treatment because of their unique properties. Among all nanomaterials, magnetic nanomaterials are considered more efficient and attractive because of their easy separation and reusable property. In this chapter, a brief review related to synthesis and characterization of MNM was studied along with their application in removal of dyes, heavy metals, and microbes from wastewater through simple adsorption processes.
Experimental Evaluation on Tribological Performance of the Wheel/Workpiece Interface in NMQL Grinding With Different Concentrations of Al2o3 Nanofluids
Authors: Li Changhe , Ali Hafiz Muhammad
Published: May 2021

As a result of the growing need for environmental protection and the increasing number of health problems faced by workers, traditional lubricants are gradually being replaced. Nanofluids, which contain nanoparticles in the proper base fluid, can serve as a low carbon, “green” lubricant. Nanofluids show improved heat transfer capability and lubricating properties. Therefore, increasing lubricating effects is an effective way to improve machining performance. The tribological properties of grinding wheel/workpiece interface with different concentration of Al2O3 nanofluid micro-lubrication grinding were studied. The influences of the force ratio, viscosity and contact angle of Al2O3 nanofluids with different concentrations on the grinding force and the surface quality of workpieces are discussed. The best concentration of Al2O3 nanofluid with good lubrication performance in grinding zone was obtained.