bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal Stability and Flame Retardancy of Polypropylene Composites Containing Siloxane-Silsesquioxane Resins
Authors: Niemczyk Arkadiusz , Dziubek Katarzyna , Sacher-Majewska Beata , Czaja Krystyna , Czech-Polak Justyna , Oliwa Rafał , Lenża Joanna , Szołyga Mariusz
Published: September 2018

A novel group of silsesquioxane derivatives, which are siloxane-silsesquioxane resins (S4SQ), was for the first time examined as possible flame retardants in polypropylene (PP) materials. Thermal stability of the PP/S4SQ composites compared to the S4SQ resins and neat PP was estimated using thermogravimetric (TG) analysis under nitrogen and in air atmosphere. The effects of the non-functionalized and n-alkyl-functionalized siloxane-silsesquioxane resins on thermostability and flame retardancy of PP materials were also evaluated by thermogravimetry-Fourier transform infrared spectrometry (TG-FTIR) and by cone calorimeter tests. The results revealed that the functionalized S4SQ resins may form a continuous ceramic layer on the material surface during its combustion, which improves both thermal stability and flame retardancy of the PP materials. This beneficial effect was observed especially when small amounts of the S4SQ fillers were applied. The performed analyses allowed us to propose a possible mechanism for the degradation of the siloxane-silsesquioxane resins, as well as to explain their possible role during the combustion of the PP/S4SQ composites.
Nanoscale Mechanical Properties and Indentation Recovery of PI@GO Composites Measured Using AFM
Authors: Zhou Ji , Cai Qiang , Xu Fu
Published: September 2018

Polyimide@graphene oxide (PI@GO) composites were prepared by way of a simple solution blending method. The nanoscale hardness and Young’s modulus of the composites were measured using nanoindentation based on atomic force microscopy (AFM). A nanoscale hardness of ~0.65 GPa and an elastic modulus of ~6.5 GPa were reached with a load of ~55 μN. The indentation recovery on the surface of PI@GO was evaluated. The results show that relatively low GO content can remarkably improve the nanoscale mechanical properties of PI.
Preparation and Evaluation of Metronidazole-Loaded Pectin Films for Potentially Targeting a Microbial Infection Associated with Periodontal Disease
Authors: Junmahasathien Taepin , Panraksa Pattaraporn , Protiarn Paytaai , Hormdee Doosadee , Noisombut Rajda , Kantrong Nutthapong , Jantrawut Pensak
Published: September 2018

The objective of this study was to develop the metronidazole loaded high and low methoxyl pectin films (HM-G-MZ and LM-G-MZ) for the treatment of periodontal disease. The films were prepared by pectin 3% w/v, glycerin 40% w/v, and metronidazole 5% w/v. The developed films were characterized by scanning electron microscope and evaluated for thickness, weight variation, and elasticity. The developed films showing optimal mechanical properties were selected to evaluate radial swelling properties, in vitro release of metronidazole and the antimicrobial activity against Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans by the disc diffusion method. The results demonstrated that LM-MZ and HM-G-MZ films were colorless and yellowish color, respectively, with the film thickness around 0.36–0.38 mm. Furthermore, both films exhibited good elasticity with low puncture strength (1.63 ± 0.37 and 0.84 ± 0.03 N/mm2, respectively) and also showed slight increase in radial swelling, so that they could be easily inserted and fitted into the periodontal pocket during a clinical use. However, HM-G-MZ showed a decrease in radial swelling after 1 h due to the film erosion. The in vitro release study of LM-G-MZ showed a burst release that was initially followed by a slow release rate profile, capable to maintain the therapeutic level in periodontal pocket for seven days, whereas HM-G-MZ showed an immediate release profile. The cumulative percentage of metronidazole release from HM-G-MZ was less than LM-G-MZ during the first 5 min as metronidazole was in a crystalline form inside HM-G-MZ film. For antimicrobial activity test, both films showed the inhibitory effect against P. gingivalis and A. actinomycetemcomitans, and there was no difference in the inhibition zone between LM-G-MZ and HM-G-MZ. The present study showed, for the first time, that low methoxyl pectin film containing glycerin and metronidazole could be potentially considered as a promising clinical tool for the drug delivery via intra-periodontal pocket to target an oral disease that is associated with polymicrobial infection.
Enhanced Mechanical and Water Absorption Properties of Rice Husk-Derived Nano-SiO2 Reinforced PHBV Composites
Authors: Wang Li , Guo Yong , Chen Yuxia , Chen Tong , Zhu Shiliu , Zhang Tingting , Liu Shengquan
Published: September 2018

Poly(3-hydroxybutyrate–co–3-hydroxyvalerate) (PHBV) is a biodegradable polymer and has several potential applications. Herein, we have used a rich biomass resource, rice husk, to obtain rice husk nano-SiO2 (RHNS) and prepared RHNS/PHBV composites by using hot-press molding. The results showed that the amorphous nature of spherical nano-SiO2 particles with an average diameter of 40–80 nm was obtained. The tensile strength and flexural strength of the RHNS/PHBV-3 composite reached up to 23.515 and 75.669 MPa, respectively, corresponding to an increase of 33.65% and 15.54% as compared to pure PHBV. The enhanced mechanical properties of the RHNS/PHBV composite can be attributed to the uniform dispersion and strong interfacial bonding of RHNS with the PHBV matrix. In addition, the water absorption rate of the RHNS/PHBV composite increased from 0.26% to 0.35% and the water swelling ratio followed the given order in different directions: thickness > width > length. Furthermore, the initial degradation temperature and residual rate of combustion at 700 °C of the composites increased with higher content of RHNS, which represents the enhanced thermal stability of RHNS/PHBV composites. In summary, RHNS served as an excellent reinforcement and RHNS/PHBV composites have shown promising properties for various potential applications.
DEM Generation from Multi Satellite PlanetScope Imagery
Authors: Ghuffar Sajid
Published: September 2018

Planet Labs have recently launched a large constellation of small satellites (3U cubesats) capable of imaging the whole Earth landmass everyday. These small satellites capture multiple images of an area on consecutive days or sometimes on the same day with a spatial resolution of 3–4 m. Planet Labs endeavors to operate the constellation in a nadir pointing mode, however, the view angle of these satellites currently varies within a few degrees from the nadir leading to varying B/H ratio for overlapping image pairs. Due to relatively small scene footprint and small off-nadir angle, the baseline to height ratio (B/H) of the overlapping PlanetScope images is often less than 1:10, which is not ideal for 3D reconstruction. Therefore, this paper explores the potential of Digital Elevation Model generation from this multi-date, multi-satellite PlanetScope imagery. The DEM generation from multiple PlanetScope images is achieved using a volumetric stereo reconstruction technique, which applies semi global matching in georeferenced object space. The results are evaluated using a LiDAR based DEM (5 m) over Mount Teide (3718 m) in Canary Islands and the ALOS (30 m) DEM on rugged terrain of the Nanga Parbat massif (8126 m) in the western Himalaya range. The proposed methodology is then applied on images from two PlanetScope satellites overpasses within a couple of minutes difference to compute the DEM of the Khurdopin glacier in the Karakoram range, known for its recent surge. The quantitative assessment of the generated elevation models is done by comparing statistics of the elevation differences between the reference LiDAR and ALOS DEM and the PlanetScope DEM. The Normalized Median of Absolute Deviation (NMAD) of the elevation differences between the computed PlanetScope DEM and LiDAR DEM is 4.1 m and the elevation differences for the ALOS DEM over stable terrain is 3.9 m. The results show that PlanetScope imagery can lead to sufficient quality DEM even with a small baseline to height ratio. Therefore, the daily PlanetScope imagery is a valuable data source and the DEM generated from this imagery can potentially be employed in numerous applications requiring multi temporal DEMs.
Reducing the Uncertainty of Lidar Measurements in Complex Terrain Using a Linear Model Approach
Authors: Hofsäß Martin , Clifton Andrew , Cheng Po Wen
Published: September 2018

In complex terrain, ground-based lidar wind speed measurements sometimes show noticeable differences compared to measurements made with in-situ sensors mounted on meteorological masts. These differences are mostly caused by the inhomogeneities of the flow field and the applied reconstruction methods. This study investigates three different methods to optimize the reconstruction algorithm in order to improve the agreement between lidar measurements and data from sensors on meteorological masts. The methods include a typical velocity azimuth display (VAD) method, a leave-one-out cross-validation method, and a linear model which takes into account the gradients of the wind velocity components. In addition, further aspects such as the influence of the half opening angle of the scanning cone and the scan duration are considered. The measurements were carried out with two different lidar systems, that measured simultaneously. The reference was a 100 m high meteorological mast. The measurements took place in complex terrain characterized by a 150 m high escarpment. The results from the individual methods are quantitatively compared with the measurements of the cup anemometer mounted on the meteorological mast by means of the three parameters of a linear regression (slope, offset, R 2 ) and the width of the 5th–95th quantile. The results show that expanding the half angle of the scanning cone from 20 ∘ to 55 ∘ reduces the offset by a factor of 14.9, but reducing the scan duration does not have an observable benefit. The linear method has the lowest uncertainty and the best agreement with the reference data (i.e., lowest offset and scatter) of all of the methods that were investigated.
Unobtrusive Vital Sign Monitoring in Automotive Environments—A Review
Authors: Leonhardt Steffen , Leicht Lennart , Teichmann Daniel
Published: September 2018

This review provides an overview of unobtrusive monitoring techniques that could be used to monitor some of the human vital signs (i.e., heart activity, breathing activity, temperature and potentially oxygen saturation) in a car seat. It will be shown that many techniques actually measure mechanical displacement, either on the body surface and/or inside the body. However, there are also techniques like capacitive electrocardiogram or bioimpedance that reflect electrical activity or passive electrical properties or thermal properties (infrared thermography). In addition, photopleythysmographic methods depend on optical properties (like scattering and absorption) of biological tissues and—mainly—blood. As all unobtrusive sensing modalities are always fragile and at risk of being contaminated by disturbances (like motion, rapidly changing environmental conditions, triboelectricity), the scope of the paper includes a survey on redundant sensor arrangements. Finally, this review also provides an overview of automotive demonstrators for vital sign monitoring.
Predicting Spatial Variations in Soil Nutrients with Hyperspectral Remote Sensing at Regional Scale
Authors: Song Ying-Qiang , Zhao Xin , Su Hui-Yue , Li Bo , Hu Yue-Ming , Cui Xue-Sen
Published: September 2018

Rapid acquisition of the spatial distribution of soil nutrients holds great implications for farmland soil productivity safety, food security and agricultural management. To this end, we collected 1297 soil samples and measured the content of soil total nitrogen (TN), soil available phosphorus (AP) and soil available potassium (AK) in Zengcheng, north of the Pearl River Delta, China. Hyperspectral remote sensing images (115 bands) of the Chinese Environmental 1A satellite were used as auxiliary variables and dimensionality reduction was performed using Pearson correlation analysis and principal component analysis. The TN, AP and AK of soil were predicted in the study area based on auxiliary variables after dimensionality reduction, along with stepwise linear regression (SLR), support vector machine (SVM), random forest (RF) and back-propagation neural network (BPNN) models; 324 independent points were used to verify the predictive performance. The BPNN model, which demonstrated the best predictive accuracy among all methods, combined ordinary kriging (OK) with mapping the spatial variations of soil nutrients. Results show that the BPNN model with double hidden layers had better predictive accuracy for soil TN (root mean square error (RMSE) = 0.409 mg kg−1, R2 = 44.24%), soil AP (RMSE = 40.808 mg kg−1, R2 = 42.91%) and soil AK (RMSE = 67.464 mg kg−1, R2 = 48.53%) compared with the SLR, SVM and RF models. The back propagation neural network-ordinary kriging (BPNNOK) model showed the best predictive results of soil TN (RMSE = 0.292 mg kg−1, R2 = 68.51%), soil AP (RMSE = 29.62 mg kg−1, R2 = 69.30%) and soil AK (RMSE = 49.67 mg kg−1 and R2 = 70.55%), indicating the best fitting ability between hyperspectral remote sensing bands and soil nutrients. According to the spatial mapping results of the BPNNOK model, concentrations of soil TN (north-central), soil AP (central and southwest) and soil AK (central and southeast) were respectively higher in the study area. The most important bands (464–517 nm) for soil TN (b10, b14, b20 and b21), soil AP (b3, b19 and b22) and soil AK (b4, b11, b12 and b25) exhibited the best response and sensitivity according to the SLR, SVM, RF and BPNN models. It was concluded that the application of hyperspectral images (visible-near-infrared data) with BPNNOK model was found to be an efficient method for mapping and monitoring soil nutrients at the regional scale.
A Novel Fault Detection with Minimizing the Noise-Signal Ratio Using Reinforcement Learning
Authors: Zhang Dapeng , Lin Zhiling , Gao Zhiwei
Published: September 2018

In this paper, a reinforcement learning approach is proposed to detect unexpected faults, where the noise-signal ratio of the data series is minimized to achieve robustness. Based on the information of fault free data series, fault detection is promptly implemented by comparing with the model forecast and real-time process. The fault severity degrees are also discussed by measuring the distance between the healthy parameters and faulty parameters. The effectiveness of the algorithm is demonstrated by an example of a DC-motor system.
Design and Implementation of an Infrared Radiant Source for Humidity Testing
Authors: Zhang Hong , Wang Chuansheng , Li Xiaorui , Sun Boyan , Jiang Dong
Published: September 2018

A novel way to measure humidity through testing the emissivity of an area radiant source is presented in this paper. The method can be applied in the environment at near room temperature (5~95 °C) across the relative humidity (RH) range of 20~90% RH. The source, with a grooved radiant surface, works in the far infrared wavelength band of 8~12 μm. The Monte-Carlo model for thermal radiation was set up to analyze the V-grooved radiant surface. Heat pipe technology is used to maintain an isothermal radiant surface. The fuzzy-PID control method was adopted to solve the problems of intense heat inertia and being easily interfered by the environment. This enabled the system to be used robustly across a large temperature range with high precision. The experimental results tested with a scanning radiant thermometer showed that the radiant source can provide a uniform thermal radiation capable of satisfying the requirements of humidity testing. The calibration method for the radiant source for humidity was explored, which is available for testing humidity.
Undercover Dogs: Pet Dogs in the Sleep Environment of Patients with Chronic Pain
Authors: Brown Cary A. , Wang Yuluan , Carr Eloise C. J.
Published: September 2018

(1) Background: Chronic pain is a significant and prevalent condition in many industrialized nations. Pain and sleep’s reciprocal nature suggests that interventions to improve sleep may decrease pain symptoms. Little attention has been paid to the influence that owning a pet dog has on the pain/sleep relationship. Typical advice to remove pets from the bedroom negates the possible positive benefit of human-animal co-sleeping. Aim: To investigate pain patients’ perceived impact of pet dog ownership on sleep. (2) Methods: We carried out a content analysis of interview data focused on the impact of pet dog ownership on sleep. The qualitative dataset comes from a subgroup of participants in a larger study examining the pain patient/canine relationship. This subgroup of participants from the larger study was asked, “Does your dog have a positive or negative impact on your sleep?” The data were thematically coded using an iterative approach. (3) Findings: Codes included: companionship; physical presence/’cuddles’; routine/schedule; distraction from anxiety/worry at night; reassuring/protective presence; active intervention to keep participant safe; daytime activity to promote sleeping at night; and reciprocal concern for the sleep of the pet dog. (4) Conclusions: Pet dogs may play important roles in helping people with chronic pain achieve sleep onset and maintenance. Removing the dog to improved sleep could be counter-productive and lead to additional sleep-related issues.
Optimum Power Loads for Elite Boxers: Case Study with the Brazilian National Olympic Team
Authors: Loturco Irineu , Bishop Chris , Ramirez-Campillo Rodrigo , Romano Felipe , Alves Mateus , Pereira Lucas , McGuigan Michael
Published: September 2018

The purpose of this case study was to examine the effects of a resistance-training program based on the optimum power loads (OPL) method on neuromuscular performance of Olympic boxing athletes during preparation for the Rio-2016 Olympic Games. Twelve elite amateur boxers from the Brazilian National Olympic Team participated in this study. Athletes were assessed at four time-points, over two consecutive competitive seasons. In the first season (considered as “control period”), the athletes executed a non-controlled strength-power training program for 10 weeks. In the second season (a seven-week experimental period), the elite boxers performed 14 power-oriented training sessions, comprising bench press (BP) and jump squat (JS) exercises at the OPL. Maximum bar-power output in BP and JS exercises was measured pre and post both training phases. Magnitude-based inferences were used to compare changes in pre and post training tests. Bar-power outputs increased meaningfully in both BP (+8%) and JS (+7%) exercises after the OPL training program. In contrast, after the control period, no worthwhile improvements were observed in the variables tested. Based on the findings of this study, highly trained boxers might benefit from the use of a training scheme based on OPL.
Oxidative Damage and Nrf2 Translocation Induced by Toxicities of Deoxynivalenol on the Placental and Embryo on Gestation Day 12.5 d and 18.5 d
Authors: Yu Miao , Wei Zhi-Yuan , Xu Zhou-Heng , Pan Jia-Qi , Chen Jian-Huan
Published: September 2018

Deoxynivalenol (DON) is a kind of natural pollutant belonging to the trichothecenes family. The aim of this study is to use diverse assays to evaluate oxidative damage as well as translocation of nuclear factor erythroid 2-related factor 2 (Nrf2), and to investigate their mechanisms in DON-induced toxicities on a placenta and embryo. Pregnant C57BL/6 mice were randomly assigned to three groups with different doses of DON: 0, 1.0, 2.5 mg/(kg·day). In gestation day (GD) 12.5 d and 18.5 d, DON induced an elevated resorption rate of the embryos as well as structural and functional damage of the placenta. In the placenta, altered levels of the antioxidant enzymes malondialdehyde, superoxide dismutase and glutathione indicated remarkable oxidative stress. Furthermore, an elevated level of heme oxygenase-1 (HO-1) and the translocation of Nrf2 from nucleus to cytoplasm indicated Nrf2/HO-1 pathway activation in DON-L group (1.0 mg/(kg·day)). It is noteworthy that the results in this experiment in GD 12.5 d were similar to those in GD 18.5 d. In conclusion, DON-induced placental oxidative damage and Nrf2 translocation were similar in GD 12.5 d and GD 18.5 d. Oxidative stress is one of the most important molecular mechanisms for embryotoxicity induced by DON, and Nrf2 translocation may play a substantial role against it.
Variability of Botulinum Toxins: Challenges and Opportunities for the Future
Authors: Rasetti-Escargueil Christine , Lemichez Emmanuel , Popoff Michel R.
Published: September 2018

Botulinum neurotoxins (BoNTs) are the most potent known toxins, and are therefore classified as extremely harmful biological weapons. However, BoNTs are therapeutic drugs that are widely used and have an increasing number of applications. BoNTs show a high diversity and are divided into multiple types and subtypes. Better understanding of the activity at the molecular and clinical levels of the natural BoNT variants as well as the development of BoNT-based chimeric molecules opens the door to novel medical applications such as silencing the sensory neurons at targeted areas and dermal restoration. This short review is focused on BoNTs’ variability and the opportunities or challenges posed for future clinical applications.
External Quality Assessment (EQA) for Molecular Diagnostics of Zika Virus: Experiences from an International EQA Programme, 2016–2018
Authors: Donoso Mantke Oliver , McCulloch Elaine , Wallace Paul S. , Yue Constanze , Baylis Sally A. , Niedrig Matthias
Published: September 2018

Quality Control for Molecular Diagnostics (QCMD), an international provider for External Quality Assessment (EQA) programmes, has introduced a programme for molecular diagnostics of Zika virus (ZIKV) in 2016, which has been continuously offered to interested laboratories since that time. The EQA schemes provided from 2016 to 2018 revealed that 86.7% (92/106), 82.4% (89/108), and 88.2% (90/102) of the participating laboratories reported correct results for all samples, respectively in 2016, 2017, and 2018. The review of results indicated a need for improvement concerning analytical sensitivity and specificity of the test methods. Comparison with the outcomes of other EQA initiatives briefly summarized here show that continuous quality assurance is important to improve laboratory performance and to increase preparedness with reliable diagnostic assays for effective patient management, infection and outbreak control.
Improving Reservoir Operation Criteria to Stabilize Water Supplies in a Multipurpose Dam: Focused on Nakdong River Basin in Korea
Authors: Kim Jungmin , Park Jinhyeog , Jang Suhyung , Kim Hyungsan , Kang Hyunwoong
Published: September 2018

Recently, torrential rain and drought have occurred in close temporal proximity and for similar durations due to changes in the spatiotemporal patterns of rainfall owing to climate change. In particular, when a drought occurs, it tends to be prolonged, making it necessary to improve the operation of multipurpose dams that not only control flooding but also serve as water supplies. In this study, standard water volume lines and action plans by response stage were improved so that water could be stored in advance of a drought instead of reservoir operation criteria set based on data from the past. The minimum water demand by use (domestic water, industrial water, and agricultural water) was also calculated. The improved reservoir operation criteria were applied to multipurpose dams in the Nakdong River Basin, and their effects were analyzed by calculating additionally secured water volumes. In the future, in case of lowered water volumes in multipurpose dams owing to a drought, the application of these improved reservoir operation criteria is expected to contribute to water supply stability by delaying entry into the drought stage and minimizing the damages caused by limited water supplies.
Insight into the Degradation of Two Benzophenone-Type UV Filters by the UV/H2O2 Advanced Oxidation Process
Authors: Du Erdeng , Li Jiaqi , Zhou Siqi , Li Miao , Liu Xiang , Li Huajie
Published: September 2018

Environmental problems caused by UV filters, a group of emerging contaminants, have attracted much attention. The removal of two typical UV filters benzophenone (BP) and 4,4′-dihydroxy-benzophenone (HBP) in water was investigated by the UV/H2O2 process. The response surface methodology (RSM) and central composite design (CCD) were applied to investigate the effects of the process parameters on the degradation rate constants, including the initial contaminant concentration, H2O2 dose, and UV light intensity. BP is more easily degraded by the UV/H2O2 process. Both processes followed pseudo-first-order kinetics. The results obtained with the built RSM model are in accordance with the experimental results (adjusted coefficients R2(adj)= 0.9835 and 0.9778 for BP and HBP, respectively). For both processes, the initial contaminant concentration (exerting a negative effect) were the most important factors controlling the degradation, followed by H2O2 dose and UV intensity (exerting positive effects). A total of 15 BP degradation products and 13 HBP degradation products during the UV/H2O2 process were identified by LC/MS and GC/MS. A series of OH radical irritated reactions, including hydroxylation, carboxylation, and ring cleavage, led to the final degradation of BP and HBP. Degradation pathways of BP and HBP were also proposed. On the whole, this work is a unique contribution to the systematic elucidation of BP and HBP degradation by the UV/H2O2 process.
Pour une didactique de l’argumentation (écrite) : problèmes, objets, propositions (I)
Authors: Masseron Caroline
Published: September 2018

Dans une perspective didactique, fondée sur l’examen critique de l’acception trop structurelle (typologique) des propositions actuelles concernant les discours argumentatifs, l’article envisage trois niveaux d’étude distincts :

a) un niveau pragmatique de contexte socio-historique et de participants,

b) un niveau d’organisation générale qui reconvertit l’intention du locuteur en une planification que l’on dira globalement polémique, délibérative ou justificatrice,

c) un niveau d’agencements discursifs locaux caractéristique d’un certain nombre d’opérations logiques et sémantiques.

Le faible rendement explicatif du niveau typologique est illustré par une comparaison de schémas théoriques dont les conclusions font apparaître l’importance des constituants (y compris qui sont implicites comme les lois de passage) au détriment d’une quelconque structure linéarisée (d’abord la thèse puis... etc).

Les extraits qui illustrent cette analyse montrent d’une part l’importance de la mise en mots des argumentations développées, d’autre part le statut constitutif variable des énoncés analysés (le même énoncé est tantôt conclusion tantôt argument), enfin leur degré d’argumentativité également variable.
Pour une didactique de l’argumentation (écrite) : problèmes, objets, propositions (II)
Authors: Masseron Caroline
Published: September 2018

Des propositions sont faites dans le but d’édifier une didactique de l’argumentation écrite :

1) S’enquérir des pratiques argumentatives spontanées des élèves, à l’écrit comme à l’oral,

2) Envisager la problématique didactique du point de vue des conduites langagières effectives de manière à établir une progression qui mette par étapes les élèves en situation d’élargir et de complexifier leur compétence argumentative initiale,

3) Se poser sérieusement le problème des extraits disponibles dans les manuels et utilisés dans les classes ; l’apprentissage de l’argumentation est au premier chef un apprentissage de la pensée et du raisonnement : en ce sens il mérite mieux que des textes prétextes choisis pour la commoditié des repérages formels demandés aux élèves,

4) Construire des séquences d’écriture longue ayant pour objet l’argumentation, à l’instar de celle qui est proposée ici et qui consiste à faire écrire un traité d’éducation par une classe de seconde.
Argumentation et discours rapporté : présentation d'une séquence didactique
Authors: Jespersen Janine , Reichler-Béguelin Marie-José
Published: September 2018

Au chapitre du discours rapporté (DR), la plupart des grammaires imposent l'idée d'une déresponsabilité du rapporteur. Or une telle vision devient non pertinente dès que l'on quitte une approche locale et décontextualisée du DR pour passer à une perspective pragmatique et discursive. La séquence didactique présentée ici entend montrer que c'est toujours le rapporteur qui mène le jeu, prélevant la citation ad hoc dans un document-source, déterminant le lieu de son implantation dans le nouveau contexte, choisissant le mode de sa reformulation. Enseigner le DR dans la perspective du discours argumentatif conduit à renouveler les exercices traditionnels. Les activités que nous proposons vont du simple repérage des actes de langage accomplis dans les discours à transposer jusqu'à un travail plus approfondi sur les conséquences de la prise en charge énonciative : savoir à qui incombe la responsabilité d'un dire est en effet crucial dans une argumentation.
Transpositions didactiques et chaîne de reformulation des savoirs : le cas des connecteurs
Authors: Garcia-Debanc Claudine
Published: September 2018

La présence du pluriel dans l'expression de «transpositions didactiques » permet de mettre en évidence les trois niveaux de transposition envisageables pour une analyse didactique : étude des écarts entre théories de référence et savoirs à enseigner, entre savoirs à enseigner et savoirs effectivement enseignés dans les classes, entre savoirs enseignés et savoirs intégrés par les élèves. Toutefois, un rapide panorama historique des grands choix théoriques en matière d'étude de l'argumentation et de son enseignement permet de montrer l'intérêt du concept de «pratique sociale de référence» à côté de celui de transposition didactique. Le concept de transposition Didactique est appliqué ici à l'étude de l'utilisation dans l'enseignement de savoirs linguistiques sur les connecteurs, plus particulièrement les analyses du connecteur mais, l'un des plus souvent décrits dans les études pragmatiques et textuelles. Après avoir défini les divers aspects de la description sémantique d'un connecteur, l'article s'applique à questionner les écarts entre les diverses descriptions sémantiques proposées par des linguistes, qui constituent les savoirs de référence, et la nature des contenus et des activités figurant dans des manuels de collège et de lycée. Les analyses mettent en évidence une rupture radicale entre ces deux sphères. En revanche, une référence lucide et permanente aux analyses linguistiques de première main peut permettre d'utiliser les descriptions sémantiques comme analyseurs des difficultés d'emploi de ces connecteurs par les élèves et d'imaginer une variété d'exercices plus efficaces, ce que montre la dernière partie de l'article.
Formation initiale des professeurs et textes officiels : des décalages à réduire
Authors: Benoît Jean-Pierre
Published: September 2018

Les décalages entre les prescriptions officielles et la formation des professeurs recrutés pour les concrétiser se sont accentués ces dernières années, puisque les épreuves des concours externes de recrutement, qui déterminent pour une large part la formation initiale, ont peu évolué, malgré la mise en place d'une épreuve «professionnelle », très vite remplacée par une épreuve «orale sur dossier », alors que le renouvellement des textes officiels s'est accéléré.

Pour comprendre ces décalages, on part de l'histoire de ces concours et on analyse leurs épreuves actuelles et leur importance relative : il semble bien que l'on continue à recruter des professeurs de Lettres pour les lycées, y compris à l'épreuve «orale sur dossier ». Comment s'étonner alors du malaise perceptible dans les réponses à des enquêtes d'opinion menées en cours de stage dans plu¬ sieurs IUFM ou de la répartition des sujets de 1 393 mémoires professionnels produits depuis 1992 dans 7 IUFM ?

Des mises à jour et des rééquilibrages sont donc nécessaires. Puisqu'on a trop attendu, il faut des changements profonds, mais il est essentiel, pour enseigner le français en fonction des programmes et des besoins sociaux, qu'ils ne portent pas que sur des dispositifs de formation.
Evidence of friction reduction in laterally graded materials
Authors: Guarino Roberto , Costagliola Gianluca , Bosia Federico , Pugno Nicola Maria
Published: September 2018

In many biological structures, optimized mechanical properties are obtained through complex structural organization involving multiple constituents, functional grading and hierarchical organization. In the case of biological surfaces, the possibility to modify the frictional and adhesive behaviour can also be achieved by exploiting a grading of the material properties. In this paper, we investigate this possibility by considering the frictional sliding of elastic surfaces in the presence of a spatial variation of the Young’s modulus and the local friction coefficients. Using finite-element simulations and a two-dimensional spring-block model, we investigate how graded material properties affect the macroscopic frictional behaviour, in particular, static friction values and the transition from static to dynamic friction. The results suggest that the graded material properties can be exploited to reduce static friction with respect to the corresponding non-graded material and to tune it to desired values, opening possibilities for the design of bio-inspired surfaces with tailor-made tribological properties.
r-process Nucleosynthesis from Three-dimensional Magnetorotational Core-collapse Supernovae
Authors: Mösta Philipp , Roberts Luke F. , Halevi Goni , Ott Christian D. , Lippuner Jonas , Haas Roland , Schnetter Erik
Published: September 2018

We investigate r-process nucleosynthesis in 3D general-relativistic magnetohydrodynamic simulations of rapidly rotating strongly magnetized core collapse. The simulations include a microphysical finite-temperature equation of state and a leakage scheme that captures the overall energetics and lepton number exchange due to postbounce neutrino emission and absorption. We track the composition of the ejected material using the nuclear reaction network SkyNet. Our results show that the 3D dynamics of magnetorotational core-collapse supernovae (CCSN) are important for their nucleosynthetic signature. We find that production of r-process material beyond the second peak is reduced by a factor of 100 when the magnetorotational jets produced by the rapidly rotating core undergo a kink instability. Our results indicate that 3D magnetorotationally powered CCSNe are robust r-process sources only if they are obtained by the collapse of cores with unrealistically large precollapse magnetic fields of the order of 1013 G. Additionally, a comparison simulation that we restrict to axisymmetry results in overly optimistic r-process production for lower magnetic field strengths.
X-Ray Absorption in Young Core-collapse Supernova Remnants
Authors: Alp Dennis , Larsson Josefin , Fransson Claes , Gabler Michael , Wongwathanarat Annop , Janka Hans-Thomas
Published: September 2018

The material expelled by core-collapse supernova (SN) explosions absorbs X-rays from the central regions. We use SN models based on three-dimensional neutrino-driven explosions to estimate optical depths to the center of the explosion, compare different progenitor models, and investigate the effects of explosion asymmetries. The optical depths below 2 keV for progenitors with a remaining hydrogen envelope are expected to be high during the first century after the explosion due to photoabsorption. A typical optical depth is 100 t
4
−2
E
−2, where t
4 is the time since the explosion in units of 10,000 days (∼27 years) and E is the energy in units of keV. Compton scattering dominates above 50 keV, but the scattering depth is lower and reaches unity at ∼1000 days at 1 MeV. The optical depths are approximately an order of magnitude lower for hydrogen-stripped progenitors. The metallicity of the SN ejecta is much higher than that in the interstellar medium, which enhances photoabsorption and makes absorption edges stronger. These results are applicable to young SN remnants in general, but we explore the effects on observations of SN 1987A and the compact object in Cas A in detail. For SN 1987A, the absorption is high and the X-ray upper limits of ∼100 

on a compact object are approximately an order of magnitude less constraining than previous estimates using other absorption models. The details are presented in an accompanying paper. For the central compact object in Cas A, we find no significant effects of our more detailed absorption model on the inferred surface temperature.
The 30 Year Search for the Compact Object in SN 1987A
Authors: Alp Dennis , Larsson Josefin , Fransson Claes , Indebetouw Remy , Jerkstrand Anders , Ahola Antero , Burrows David , Challis Peter , Cigan Phil , Cikota Aleksandar , Kirshner Robert P. , van Loon Jacco Th. , Mattila Seppo , Ng C.-Y. , Park Sangwook , Spyromilio Jason , Woosley Stan , Baes Maarten , Bouchet Patrice , Chevalier Roger , Frank Kari A. , Gaensler B. M. , Gomez Haley , Janka Hans-Thomas , Leibundgut Bruno , Lundqvist Peter , Marcaide Jon , Matsuura Mikako , Sollerman Jesper , Sonneborn George , Staveley-Smith Lister , Zanardo Giovanna , Gabler Michael , Taddia Francesco , Wheeler J. Craig
Published: September 2018

Despite more than 30 years of searching, the compact object in Supernova (SN) 1987A has not yet been detected. We present new limits on the compact object in SN 1987A using millimeter, near-infrared, optical, ultraviolet, and X-ray observations from ALMA, VLT, HST, and Chandra. The limits are approximately 0.1 mJy (

erg s−1 cm−2 Hz−1) at 213 GHz, 1 L
⊙ (

erg s−1 cm−2 Hz−1) in the optical if our line of sight is free of ejecta dust, and 1036 erg s−1 (

erg s−1 cm−2 Hz−1) in 2–10 keV X-rays. Our X-ray limits are an order of magnitude less constraining than previous limits because we use a more realistic ejecta absorption model based on three-dimensional neutrino-driven SN explosion models. The allowed bolometric luminosity of the compact object is 22 L
⊙ if our line of sight is free of ejecta dust, or 138 L
⊙ if dust-obscured. Depending on assumptions, these values limit the effective temperature of a neutron star (NS) to

–8 MK and do not exclude models, which typically are in the range 3–4 MK. For the simplest accretion model, the accretion rate for an efficiency η is limited to

M
⊙ yr−1, which excludes most predictions. For pulsar activity modeled by a rotating magnetic dipole in vacuum, the limit on the magnetic field strength (B) for a given spin period (P) is

G s−2, which firmly excludes pulsars comparable to the Crab. By combining information about radiation reprocessing and geometry, we infer that the compact object is a dust-obscured thermally emitting NS, which may appear as a region of higher-temperature ejecta dust emission.
Protoplanetary Disk Sizes and Angular Momentum Transport
Authors: Najita Joan R. , Bergin Edwin A.
Published: September 2018

In young circumstellar disks, accretion—the inspiral of disk material onto the central star—is important for both the buildup of stellar masses and the outcome of planet formation. Although the existence of accretion is well documented, understanding the angular momentum transport mechanism that enables disk accretion has proven to be an enduring challenge. The leading theory to date, the magnetorotational instability, which redistributes angular momentum within the disk, is increasingly questioned, and magnetothermal disk winds, which remove angular momentum from the disk, have emerged as an alternative theoretical solution. Here we investigate whether measurements of disk radii can provide useful insights into which, if either, of these mechanisms drives disk accretion, by searching for evidence of viscous spreading in gaseous disks, a potential signature of “in-disk” angular momentum transport. We find that the large sizes of most Class II (T Tauri) gas disks compared to those of their earlier evolutionary counterparts, Class I gas disks, are consistent with expectations for viscous spreading in the Class II phase. There is, however, a large spread in the sizes of Class II gas disks at any age, including a population of very small Class II gas disks. Their small sizes may result from processes such as photoevaporation, disk winds, or truncation by orbiting low-mass companions.
Sofosbuvir/Velpatasvir/Voxilaprevir: A Highly Effective Option for Retreatment of Hepatitis C in Difficult-to-treat Patients
Authors: Mathur Poonam , Kottilil Shyamasundaran , Wilson Eleanor
Published: September 2018

Treatment for hepatitis C has escalated rapidly since the advent of direct-acting antivirals. Although there are highly efficacious, pangenotypic regimens available as standard of care, 5–10% of patients do not achieve virological cure. The recently approved fixed-dose combination of sofosbuvir, velpatasvir and voxilaprevir provides an option for retreatment in patients who have failed prior regimens and have characteristics which make them difficult to treat. This review provides a summary of the evidence for use of Vosevi®, a fixed-dose combination pill for treatment of hepatitis C in treatment-experienced patients.
Evolución y proceso de fabricación de imanes “NEO” aplicados a motores de vehículos eléctricos
Authors: Abad Victoria , Sagredo Jesús
Published: September 2018

Tras el desarrollo de los imanes Nd-Fe-B o “Neo”, éstos son ahora componentes esenciales en muchos campos de la tecnología debido a su capacidad para proporcionar un fuerte flujo magnético. Existen dos técnicas bien establecidas para la fabricación de imanes de tierras raras: a) el uso de la metalurgia de polvo para obtener cuerpos magnéticos de alto rendimiento, anisotrópicos, totalmente densos; y b) el proceso de hilado por fusión o HDDR (hidrogenación, decrepitación, desorción y recombinación) se usa ampliamente para producir polvos magnéticos para imanes aglomerados. En la industria de los imanes de Nd-Fe-B sinterizados, la producción total ha aumentado y su aplicación dominante es principalmente motores y en particular, su uso para automóviles híbridos es una de las aplicaciones más atractivas. También se han utilizado imanes aglomerados para motores pequeños, los estudios de nanocompuestos y de imanes Sm-Fe-N se han generalizado. Este artículo revisa el estado actual y las tendencias futuras en la investigación de imanes permanentes.
QUAL É A GRAÇA?: HUMOR E TEORIA DA MENTE EM DESENVOLVIMENTO
Authors: Benedito Caroline de Macedo , Nogueira Stephanie Cristine , Souza Débora de Hollanda
Published: September 2018

O presente estudo teve como objetivo principal investigar a relação entre o desenvolvimento da teoria da mente e a apreciação de humor. Participaram 41 crianças de quatro a 11 anos (Midade = 7 anos e 11 meses, DP = 23,8 meses), que foram agrupadas segundo o seu desempenho em quatro tarefas de crença falsa. As crianças ouviram três piadas e acompanharam três quadrinhos, todos direcionados ao público infantil, e foram solicitadas a indicar quão engraçada/o era cada piada/quadrinho. As análises revelaram correlação significativa entre o desempenho nas tarefas de crença falsa e a avaliação das piadas. As crianças com uma teoria da mente mais avançada (G2 e G3) apreciaram mais as piadas do que as crianças do grupo que não obteve sucesso nas tarefas de crença falsa de primeira ordem. Não foram encontradas diferenças significativas entre os grupos de teoria da mente em relação à apreciação dos quadrinhos. Os resultados corroboram a proposta de que o humor é um bom indicador de desenvolvimento sociocognitivo e apontam para uma linha de investigação promissora na psicologia do desenvolvimento.
A RELAÇÃO ENTRE PSICOPATOLOGIAS NÃO NEURÓTICAS, NEUROSE OBSESSIVA E PULSÃO DE MORTE
Authors: Paiva Aldo Ivan Pereira
Published: September 2018

As psicopatologias não neuróticas, categoria descrita por André Green, são caracterizadas por problemas na constituição do eu, envolvendo basicamente uma fragilidade narcísica, falhas nos processos de simbolização, além da tendência à atuação e à compulsão, sem o recurso da elaboração psíquica, e a predominância de uma economia do trauma relacionada ao gozo e ao excesso pulsional. São manifestações dessa psicopatologia as somatizações, a síndrome do pânico, as adições, os transtornos alimentares, os estados-limítrofes e a depressão. Green considera que a pulsão de morte, compreendida a partir do processo de desinvestimento dos objetos ou função desobjetalizante, seria um conceito fundamental para a compreensão das não neuroses. A partir da teoria freudiana é possível estabelecer uma relação entre a não neurose e a neurose obsessiva, tendo em vista a utilização de mecanismos defensivos semelhantes e o papel marcante da pulsão de morte, garantindo ainda o lugar da sexualidade infantil inconsciente como fator etiológico predominante.
A PERCEPÇÃO ESTÉTICA NA FENOMENOLOGIA DE DUFRENNE: CONTRIBUIÇÕES POSSÍVEIS PARA A PSICOLOGIA
Authors: Milhorim Thaís Kristine , Telles Thabata Castelo Branco
Published: September 2018

Estética é um ramo da filosofia que corresponde, de maneira geral, ao  estudo da sensibilidade e das artes. Mikel Dufrenne (1910-1995), filósofo francês, é considerado um dos mais prestigiados estudiosos da relação entre arte, estética e fenomenologia. Este estudo busca a compreensão da maneira como se estabelece a constituição da percepção estética na terceira parte da obra Phénoménologie de l’expérience esthétique, de Dufrenne, que trata da fenomenologia da percepção estética. O presente artigo pretende, também, compreender a possível repercussão dessa constituição para as vivências psíquicas humanas. A leitura do material foi realizada com foco  nas  distintas categorias que compõem a percepção estética para o  autor, sendo levantadas suas principais características. Observa-se que a percepção estética, diferente da percepção comum, propicia qualidades que proporcionam novos sentidos e atmosferas, novas formas de ver, pensar ou sentir, para além do que está constituído. Ela possibilita  configurar,  assim,  novas formas de ser e estar no mundo.
A EXPERIÊNCIA DA MATERNIDADE DURANTE O TRATAMENTO PARA O CÂNCER
Authors: Castro Elisa Kern de , Kenne Dornel Ana Luisa , Alves de Sousa Miguel
Published: September 2018

O objetivo do estudo foi investigar a experiência da maternidade de mulheres com câncer com pelo menos um filho menor de dez anos. A partir de um delineamento qualitativo exploratório, foram realizadas entrevistas com dez mães, gravadas em áudio e transcritas. A análise de conteúdo identificou cinco categorias temáticas: 1) Ser mãe é... Sentir medo da morte/recidiva e de deixar o filho órfão; 2) Ser mãe é... Mudar os valores/sentido da vida com a doença; 3) Ser mãe é... Alterar a rotina da vida familiar/da criança; 4) Ser mãe é... Ter sentimentos conflitantes/de derrota/ambivalentes; 5) Ser mãe é... Ter dificuldade em atender aos filhos. A fala das mães foi avaliada por dois juízes independentes. Observou-se que as experiências do câncer e da maternidade se sobrepõem e intensificam o sofrimento dessas mulheres. Ao mesmo tempo, ambas as experiências colocam essas mulheres diante de situações que as levam a ressignificar sua  vida e suas prioridades, o que pode potencializar a sua relação com os filhos de uma maneira positiva.