Stationary shocks in periodic highly nonlinear granular chains

We study the existence of stationary shock waves in uniform and periodic heterogeneous highly nonlinear granular chains governed by a power-law contact interaction, comparing discrete and continuum approaches, as well as experiments. We report the presence of quasisteady shock fronts without the need for dissipative effects. When viscous effects are neglected, the structure of the leading front appears to be solely the result of dispersive effects related to the lattice wave dispersion and, for heterogeneous bead chains, to the impedance mismatch between material domains. We report analytically and numerically the shock-width scaling with the variation in the particles periodicity (cell size) and compare the obtained results with experiments. We check the state (−) behind the shock front via quasistatic compression analysis and report a very good agreement between theory and numerical data

The disappearance of cultural landscapes: the case of wooded-meadows in the Ligurian Apennines (NW Italy)

The \u201cwooded-meadows system\u201d is a multifunctional use of vegetation resources widespread in Europe since the Neolithic, and well documented in the Ligurian Apennines (NW Italy) between the Middle Ages and the first half of the 19th century. The management of wooded-meadows included: collection of fallen and dead branches in spring, later used for fuel; mowing and grazing in summer; collection of secondary products; making sheaves from branches in autumn, later used as cattle and sheep fodder; coppicing, pollarding and cutting of trees in winter. Three sites located in eastern Ligurian Apennines were studied by means of an interdisciplinary approach in order to better understand the impact and the consequences of this historical landuse practice on vegetation structure and composition. In particular, based on specific features of palynological diagrams, it was possible to conclude that (compared to the post-cultural phase) \u2013 when the wooded-meadows system was in use all the sites were characterized by: (1) lower pollen percentages of trees; (2) higher pollen percentages of shrubs and herbs; (3) higher percentages of anthropogenic pollen indicators; (4) higher values of palynological richness. This research also represents a contribution to issues of nature-conservation policy for the preservation of cultural landscapes

Stone Age–Early Metal Period transition in the southern Finnish Lake District: incipient forest grazing and temporary burning practices

Peer reviewe

Waste recycling in ceramic tiles: a technological outlook

The ceramic industry is going to be deeply involved in the transition to a circular economy. However, the main obstacle to a widespread recourse to waste recycling is the lack of knowledge about its effect in ceramic tile manufacturing. The rationale behind this work is to look at recycling from the industrialist's point of view. The goal is overviewing the effects of different kinds of waste on technological behavior, technical performance, and environmental impact of ceramic tiles in the prospect of an industrial transfer. Technical constraints that waste recycling must comply to be transferable to ceramic tile manufacturing were examined in detail. Available information on the behavior of ceramic tile bodies containing wastes from various sources was critically reviewed for every manufacturing stage. The main outcome is an outlook about feasibility (expressed in terms of Technology Readiness Level) and recommended recyclable amount. In addition, hindrances to scale up and matters of concern (e.g., hazardous components and gaseous emissions) are pointed out and discussed. Examples and reasons of success/unsuccess are briefly illustrated, and prospect of waste recycling in ceramic tiles production from a circular economy perspective was appraised

Up-Grade of Catalysts for Medium and High Temperature Water Gas Shift Reaction

The Water Gas Shift (WGR) reaction plays a fundamental role in the production of H2 or syngas, which are widely used in the chemical industry to produce building blocks or fuels. Considering the very large global request of these molecules, each improvement in the WGS processes generates a huge return on investment for the industries and for this reason, this reaction is still under investigation. This PhD thesis aimed to upgrade the Medium and High Temperature Shift process by improving the catalytic formulations or finely tuning the reaction conditions. For the MTS formulations, the introduction of small amounts of elements such as La, Zr and Ce resulted in a significant improvement of the physical properties, with a corresponding increase, especially in case of Ce, of the CO conversion and the catalyst stability. On the other hand a small amount of Mg increases the stability and the catalytic performances, while the same amount of Ba does not affect the catalytic behavior. Finely, the role of the different reaction parameters on the methylamine formation and, consequently, on the deactivation by carbonaceous deposits was proposed. Novel catalyst formulations were successfully obtained also in case of HTS, favoring the economic items of this process, with a strong increase of CO conversion and very low deactivation with time-on-stream by addition of very small amounts of Ga. This effect was attributed to the tendency of Ga to favor the formation of spinel-type phases that stabilized the metallic copper, resulting in a decrease in particle sizes. The high stability of Cu- and Ga-containing spinel-type phases and their controlled reduction are the key factors to favor the catalytic activity and reduce the copper sintering, main cause of catalyst deactivation

PubMed, Clinicaltrials.gov: a critical analysis of new features after three years from the launch of the new release. Results from an interactive training course

Three years after the launch of the new release of the PubMed database and new platform for searching clinical trials "Clinicaltrials.gov", GIDIF Academy organized a course aimed at biomedical documentarians and librarians. These portals, with free access, are known to the scientific community as the reference for bibliographic research of information in scientific literature. In the classroom, the high motivation of the participants was further powered by the careful analysis of the modernization innovations proposed by the NLM for the two platforms. The speakers, interacting lively with the learners, highlighted the strengths and analysed the fragilities of the two systems with the aim of finding possible solutions to obtain effective and safe queries; finally, the collection of opinions offered ideas and room for improvement in the performance of the platforms themselves

Hybrid Metaheuristic Approach to Solve the Problem of Containers Reshuffling in an Inland Terminal

The paper deals with the problem of minimizing the reshuffling of containers in an inland intermodal terminal. The problem is tackled according to a hybrid approach that combines a preliminary selection of heuristics and a genetic algorithm. The heuristics are used to determine the initial population for the genetic algorithm, which aims to optimize the locations of the containers to store in the yard in order to minimize the operational costs. A simulation model computes the costs related to storage and pick-up operations in the yard bay. The proposed optimization method has been calibrated by selecting the optimal parameters of the genetic algorithm in a toy case and has been tested on a theoretical example of realistic size. Results highlighted that the use of a suitable heuristic to generate the initial population outperforms the genetic algorithm, initialized with a random solution, by 20%

Teacher justice and parent support as predictors of learning motivation and visions of a just world

In this study we explore teacher justice and parent support in learning motivation and visions of a just world. The study sample was 509 Italian secondary school students, 163 males and 346 females. Regression analyses investigated the impact of teacher justice, parental involvement and factors of school choice (one\u2019s interests and parental influence) on learning motivation, personal beliefs in a just world, civic engagement and a positive future orientation. Findings confirm that the feeling of being treated fairly in the classroom is an important factor for adolescent adjustment since it relates to the development of learning motivation, personal beliefs in a just world, and civic engagement. Parental academic involvement also emerges as a significant resource for adolescents, and the most important in having an effect on the development of a positive future orientation

Quelle(s) collaboration(s) dans les dictionnaires en ligne ? Les cas du Wiktionnaire et du Dictionnaire des francophones

Dans cet article, nous étudions l’aspect collaboratif de deux dictionnaires numériques de la langue française, le Wiktionnaire et le Dictionnaire des francophones. Pour ce faire, nous analyserons deux axes apparemment différents mais qui parviennent à se croiser : d’un côté, les espaces et les modalités d’interaction entre usagers et modérateurs des dictionnaires, de l’autre, le retentissement de ces outils dans les réseaux sociaux dans le but de montrer les représentations élaborées et diffusées dans ces espaces, dans le cadre théorique de la « linguistique populaire » (Achard-Bayle et Paveau, 2008) et des études sur le Web 2.0 (Cardon, 2019).In this article, we study the collaborative aspect of two digital dictionaries of the French language, the Wiktionnaire and the Dictionnaire des francophones. To do this, we will analyze two apparently different axes that manage to intersect: on the one hand, the spaces and modes of interaction between users and moderators of dictionaries, on the other, the impact of these tools in the networks in order to show the representations developed and disseminated in these spaces, within the theoretical framework of « popular linguistics » (Achard-Bayle & Paveau, 2008) and studies on Web 2.0 (Cardon, 2019)

La polémique autour de bonjour/hi sur le web : vers la déconstruction du discours d’autorité

En novembre 2019, Simon Jolin-Barrette, ministre québécois responsable de la langue française, revient sur une polémique qui avait eu lieu deux ans auparavant et qui portait sur la formule de salutation bilingue bonjour/hi, employée dans les commerces montréalais et considérée par certains comme signe du déclin du français au Québec. Le ministre déclare avoir l’intention d’interdire cette formule au profit du rituel français de salutation bonjour. Or, dans un contexte sociolinguistique comme celui du Québec, une telle affirmation ne peut passer inaperçue et une nouvelle polémique éclate. Notre objectif est de montrer comment les réactions suscitées – dans l’arène politique et les médias, mais surtout au sein de la population s’exprimant en ligne – ont contribué à la déconstruction du discours du ministre et à son incapacité à s’imposer comme discours d’autorité. Notre attention porte principalement sur les modalités (techno)discursives au moyen desquelles les participants aux échanges affaiblissent, voire nient, l’autorité du ministre.In November 2019, Simon Jolin-Barrette, Quebec minister responsible for the French language, revisited a controversy that had taken place two years earlier concerning the bilingual greeting bonjour/hi used in Montreal businesses, considered by some to reflect the decline of the French language in Quebec. The minister stated that he intended to ban the greeting in favor of the French ritual bonjour. In a conflicted sociolinguistic context such as Quebec’s, such assertions cannot go unnoticed. The announcement of Jolin-Barrette resounded in the media, where it provoked strong reactions to such an extent that a new polemic broke out. The aim of this article is to show how the reactions provoked, especially online, contributed to the deconstruction of the minister’s discourse and to its inability to impose itself as a discourse of authority. Our analysis focusses on the (techno)discursive modalities through which Jolin-Barrette’s authority is diminished or denied