bluuebunny/crossref_metadata_2025 huggingface dataset:
"Conversations réflexives" dans la classe de langues virtuelle par conférence asynchrone
Authors: Lamy Marie-Noëlle , Goodfellow Robin
Published: January 2012

A l’Open University, université britannique de télé-enseignement, les concepteurs de matériaux utilisent depuis longtemps des pédagogies qui amènent l’apprenant à réfléchir sur son apprentissage et à expliciter cette réflexion. Or aujourd’hui les Technologies de l’Information et de la Communication (TIC) leur permettent de faire interagir apprenants, professeurs et locuteurs natifs. Ainsi l’apprenant participe à la communication et reçoit en retour des messages en langue cible, dont il se sert pour améliorer sa compétence communicative. Qu’en est-il, dès lors, du rôle de la réflexion consciente dans le processus d’apprentissage ? Vu les importantes possibilités d’interactivité offertes par les TIC, doit-on encore prôner la réflexion consciente dans le télé-enseignement ? Nous répondons par l’affirmative, considérant que les concepteurs d’environnements virtuels doivent faciliter et la réflexion consciente et l’interactivité spontanée. Nous soutenons que la conférence télématique asynchrone est un outil qui permet d’atteindre cet objectif. Nous cherchons à voir dans quelle mesure la réflexivité et l’interactivité interviennent dans ce type de conférence, et à préciser la valeur pédagogique de ces échanges. Nous étudions une conférence organisée pour des étudiants de français langue étrangère (FLE) et nous proposons une pédagogie visant à promouvoir ce que nous appelons des "conversations réflexives", c’est-à-dire des échanges privilégiant des thèmes langagiers ou portant sur l’apprentissage même des langues.
Éditorial
Authors: Rézeau Joseph
Published: January 2012

Éditorial du numéro 2, volume 2 de la revue Alsic, initialement publié sous un autre format, voir document attaché.
De l’usage des courbes sonores et autres supports graphiques pour aider l’apprenant en langues.
Authors: Cazade Alain
Published: January 2012

Les logiciels de langues ont abondamment recours à l´affichage de courbes sonores autant pour rehausser leur crédibilité que pour tenter d´aider l´apprenant à fabriquer un lien entre sa production vocale et l´exemple qu´on lui demande d´imiter, alors qu´il ne sait seulement pas, le plus souvent, comment commencer à améliorer l´une pour mieux reproduire l´autre. Ces courbes sonores, de simples oscillogrammes la plupart du temps, peuvent- elles jouer un rôle quelconque dans ce sens ? Au moment où à tous les niveaux l´accent semble être enfin mis sur l´importance de la phonétique, de même que sur les spécificités de l´entraînement à la pratique de l´oral dans l´enseignement des langues vivantes, il semble intéressant ce poser cette question même si nombreux sont ceux qui considèrent que de telles courbes sonores n´apportent rien, essentiellement pour l´insuffisance de l´information utile qu´elles contiennent. Si tel est le cas, on peut chercher à définir quels affichages aideraient les apprenants à mieux appréhender les mécanismes de la phonation et à faire progresser la qualité de leur prononciation. Une évolution semble déjà se dessiner qui vise à dépasser les faiblesses constatées. Il sera intéressant de voir si cette évolution va dans le bon sens.
Définition d'un profil d'apprenant en situation d'auto-évaluation
Authors: Bourdet Jean-François , Teutsch Philippe
Published: January 2012

Ce texte présente un projet de recherche pluridisciplinaire (didactique du FLE et EIAO) centré sur la modélisation de l'apprenant. Le système GCSE valide les compétences d'un public placé en situation d'évaluation par un environnement multimédia de test des habiletés linguistiques. Le repérage et le classement des erreurs par le système permettent de constituer des corpus de fautes rendus accessibles avec leur contexte de production. On dispose ainsi d'éléments nécessaires à la constitution d'un profil par la mise en forme de différents niveaux : validation de la compétence globale, performances spécifiques dans telle partie du texte, types d'erreurs récurrents, corpus constitués des fautes rencontrées. Les outils mis en place ont pour but d'aider l'utilisateur à construire un parcours d'auto-évaluation : relecture des activités, mise en relation d'éléments originellement séparés. Ils permettent également à un évaluateur de disposer d'indices pertinents quant au niveau de performance atteint par l'apprenant.
La conception des environnements d'apprentissage : de la théorie à la pratique / de la pratique à la théorie
Authors: Depover Christian , Quintin Jean-Jacques , De Lièvre Bruno
Published: January 2012

Cet article présente une approche en matière de conception d'environnements d'apprentissage multimédia qualifiée d'incrémentielle et d'itérative en ce sens qu'elle repose sur un affinage progressif du produit dans le cadre d'un partenariat étroit entre concepteur et client. L'approche proposée implique notamment la mise au point de prototypes qui feront l'objet de validations systématiques afin d'assurer l'adéquation avec les exigences et les contraintes du milieu d'accueil. S'appuyant sur une double posture de chercheur et de concepteur, l'approche se nourrit de la théorie en s'appuyant sur des modèles mais elle nourrit également la théorie à travers l'effort de modélisation qui l'accompagne.
Une expérience de recherche documentaire sur Internet en classe de langue : propositions de modélisation didactique
Authors: Verreman Alain
Published: January 2012

Dans le cadre du cours d'allemand, des classes de lycée (120 élèves concernés) ont effectué des recherches guidées sur des sites Internet. L'expérience décrite sert de base, tout d'abord, à une réflexion sur l'opportunité didactique de recherches documentaires sur Internet, en cours de langue étrangère. En effet, l'intérêt de cette activité n'est réel que si elle donne lieu à la mise en place d'un dispositif d'apprentissage. Des conclusions sont tirées sur les écueils à éviter, les principes à respecter et sur les perspectives nouvelles que ce média ouvre dans le domaine des "méthodes actives", de l'autonomisation de l'apprenant et de la production en langue étrangère. Le dispositif utilisé fait ensuite l'objet d'une réflexion didactique approfondie. Il est passé au crible des critères de variation, de différenciation, de pertinence et de cohérence. Puis les résultats sont comparés aux travaux publiés dans ce domaine en France et en Allemagne. Enfin, une proposition de modélisation fait apparaître que le dispositif utilisé a une double appartenance : au modèle culturel et au modèle de la tâche complexe, ceux-ci étant définis par leurs dominantes, leurs activités typiques, leurs objectifs formatifs, leurs principes didactiques et leurs finalités éducatives.
Gérer l'interface entre ingénierie, didactique, pédagogie et dispositifs ouverts
Authors: Demaizière Françoise , Achard-Bayle Guy
Published: January 2012

Nous proposons de croiser le regard du didacticien linguiste et celui du spécialiste de l'utilisation des TIC pour la formation et de l'ingénierie de formation, afin d'analyser des dispositifs expérimentaux "ouverts" que nous avons pu observer de près. Le premier est un dispositif à distance basé sur une pédagogie du projet, le second relève de l'autoformation guidée en centre de ressources. Dans les deux cas on relève le rôle pivot du centre de ressources et la disparition du groupe-classe. Quelques points importants pour une approche des dispositifs ouverts se dégagent, entre autres tutorat et suivi des apprenants, rapport au temps (temps perdu, temps retrouvé), choix des ressources supports des apprentissages (outils de référence et matériaux pédagogiques). Nous plaiderons pour une meilleure gestion de l'interface entre ingénierie, didactique, pédagogie et dispositifs ouverts par une remobilisation du didacticien autour de quelques axes se dégageant de nos observations.
La correction et la révision de l'écrit en français langue seconde : médiation humaine, médiation informatique
Authors: Cordier-Gauthier Corinne , Dion Chantal
Published: January 2012

L'apprentissage de la correction / révision de l'écrit par les apprenants de français langue seconde peut-elle tirer profit des correcteurs orthographiques et grammaticaux des traitements de texte ou des correcticiels spécialisés ? La nature de la médiation informatique permet-elle aux apprenants de corriger de façon efficace leurs textes et comment se compare-t-elle avec la correction humaine ? Qu'est-ce qui différencie ces deux médiations ? Des textes rédigés par des anglophones ont été soumis aux deux types de corrections, humaine et informatique, soit deux enseignantes ayant vingt ans d'expérience et la correction informatique effectuée par le correcteur orthographique et grammatical de Word et les deux correcticiels canadiens, Le correcteur 101 et Antidote. Les résultats montrent que la nature de ces médiations n'est pas comparable et que la médiation informatique, pour être efficace, nécessite la participation active, intelligente et instruite de l'utilisateur et que les correcticiels ne peuvent pas corriger efficacement des textes d'étudiants de niveau intermédiaire.
Rédactions conversationnelles sur papier et sur ordinateur : une étude de cas
Authors: Dejean Charlotte
Published: January 2012

Très récemment encore, le modèle de l'apprenant seul face à l'ordinateur était dominant car l'ordinateur était considéré avant tout comme un outil favorisant l'individualisation de l'apprentissage. Depuis quelques années, les technologies au service de l'apprentissage sont envisagées comme pouvant faciliter les interactions sociales (enseignant-apprenants et apprenants-apprenants). C'est dans cette perspective que s'est développé, notamment dans le monde anglophone, un domaine de recherche sur les Apprentissages Collaboratifs Assistés par Ordinateur (ACAO). Les situations de travail auxquelles s'intéresse ce domaine sont le travail à deux ou plusieurs face à un même ordinateur et le travail à plusieurs par le biais de l'ordinateur, c'est-à-dire en réseau (local ou Internet). La situation qui fait l'objet de cette étude relève de la première catégorie évoquée ; on s'intéresse en effet aux interactions entre deux apprenants de Français Langue Étrangère (FLE), rédigeant ensemble un texte avec un même ordinateur. Ces apprenants participent donc à ce que l'on appelle une "rédaction conversationnelle" ou une rédaction collaborative.
Caractérisation des interfaces porteuses d'information mises en œuvre dans un environnement informatique d'aide à l'apprentissage de la lecture
Authors: Pélissier Chrysta
Published: January 2012

Dans cet article, nous souhaitons présenter une caractérisation des interfaces porteuses d'information présentes dans un module de type ressource dédié à l'apprentissage d'un domaine. Le domaine d'application choisi est l'apprentissage de la lecture et plus particulièrement, nous nous intéressons à l'environnement informatique du projet AMICAL (Architecture Multi-agents Compagnon pour l'Apprentissage de la Lecture). Dans cet environnement, sont intégrés plusieurs modules. Parmi eux, le Module Ressource Lexical (MRL) donne la possibilité à l'apprenant d'abord de sélectionner un élément lexical et ensuite de visiter une ou plusieurs interfaces porteuses d'information associée à cet élément. Les interfaces porteuses d'information mises en jeu dans un tel module sont appelées « situations ». Elles se caractérisent d'une part par un objectif et d'autre part par un déroulement. L'objectif correspond à une ou plusieurs connaissances liées au domaine que l'apprenant doit acquérir au cours de son apprentissage et que l'on choisit de mettre en œuvre plus particulièrement dans cette situation. Le déroulement se caractérise par une structure d'évènements composés eux d'une structure de couples (, moyen).
Mobile Computing
Authors: Rahman Hakikur , Kumar Senthil
Published: January 2012

With the advent of complex but user friendly mobile communications technologies and transformation of mobile devices being handy for usage, the applications and utilities of mobile devices have come into the palm of almost each and every human being of this modern world. Furthermore, with the unprecedented growth of the Internet and its outreach, the demand and requirement of users are growing fast, ranging from basic livelihood support, to infotainment, to social networking. Applications of mobile devices nowadays do not include only the facilities for calling another cell phone and text messaging, but also connecting to social networks, service providers networks, and servers of various organizations, like academic or business or health sector, thus providing appropriate services to users, meeting daily demands including emergencies . However, all these are dependent on technologies, social, cultural, and economic issues, which this study has explored. This chapter is based on a survey of concurrent literatures on mobile computing, its applications, and challenges. This study has put forwards three applications of mobile computing: learning, health, and GIS. In this aspect, by exploring the background on mobile computing, the chapter discusses a few constraints and challenges that have emerged in terms of design and application issues. Thereafter, before the conclusion, the chapter puts forward a few future research hints.
Architecture for Integrated Mobile Calendar Systemsi
Authors: Frank Lars
Published: January 2012

In central databases the consistency of data is normally implemented by using the ACID (Atomicity, Consistency, Isolation, and Durability) properties of a DBMS (Data Base Management System). This is not possible if distributed and/or mobile databases are involved, and the availability of data also has to be optimized. The objective of this chapter is to describe an architecture for mobile integrated calendar systems where performance, local autonomy, and availability are optimized by using relaxed ACID properties and different asynchronous replication methods. By using relaxed ACID properties across different database locations it is possible for the users to trust the data they use even if the distributed database temporarily is inconsistent. It is also important that disconnected locations can operate in a meaningful way in so-called disconnected mode.
Applications of Graph Theory Algorithms in Mobile Ad hoc Networks
Authors: Meghanathan Natarajan
Published: January 2012

Various simulators (e.g., ns-2 and GloMoSim) are available to implement and study the behavior of the routing protocols for Mobile Ad hoc Networks (MANETs). However, students and investigators who are new to this area often get perplexed in the complexity of these simulators and lose the focus in designing and analyzing the characteristics of the network and the protocol. Most of the time is spent in learning the existing code modules of the simulator and the logical flow between the different code modules. The purpose of this chapter is to illustrate the applications of Graph Theory algorithms to study, analyze, and simulate the behavior of routing protocols for MANETs. Specifically, the chapter focuses on the applications of Graph Theory algorithms to determine paths, trees, and connected dominating sets for simulating and analyzing respectively unicast (single-path and multi-path), multicast, and broadcast communication in mobile ad hoc networks (MANETs). The chapter discusses the (i) Dijkstra’s shortest path algorithm and its modifications for finding stable paths and bottleneck paths; (ii) Prim’s minimum spanning tree algorithm and its modification for finding all pairs smallest and largest bottleneck paths; (iii) Minimum Steiner tree algorithm to connect a source node to all the receivers of a multicast group; (iv) A node-degree based algorithm to construct an approximate minimum Connected Dominating Set (CDS) for sending information from one node to all other nodes in the network; and (v) Algorithms to find a sequence of link-disjoint, node-disjoint, and zone-disjoint multi-path routes in MANETs.
Network Mobility Management in the ITS Context
Authors: Toledo Nerea , Higuero Marivi
Published: January 2012

The proposals suggested so far can be can be classified in two different categories: on the one hand, NEMO solutions that consider MIPv6 as the base host mobility management protocol, and on the other hand, solutions that consider alternative base host mobility management protocols like SIP, LIN6, or HIP. Besides, a taxonomy on MIPv6 based NEMO protocols classifying them by considering which characteristics they aim to enhance is provided. It is important to point out that the selection of the base host mobility management protocol is fundamental to have as many demanded key features satisfied as possible by the NEMO protocol to be applied in the Intelligent Transportation System (ITS) context.
GSM
Authors: Srinivasa K.G. , R Vijayendra , Harish Raddi C.S. , Anil Kumar M.
Published: January 2012

The objective of this chapter is to provide an innovative system for tracking and monitoring objects using RF transmitters and receivers, and querying about these objects using mobile phones. The protocol for the system and a simulation to check the feasibility of this project before applying it to a real world scenario is presented below. In this simulation, capability of the transmitter and receiver is tested to communicate effectively and also display the data sent by the transmitter. As a result, a highly flexible wireless controlled system would enable bridging the distance between the user and the electronic device, and hence, provide easier access to real world entities, by just manoeuvring the mobile phones, without the need to be physically present near the object. Also, it is being enhanced to ensure an authenticated access to these resources, thereby taking care of the security aspect. The working of the system can be divided into two phases: phase one comprises a pair of RF transmitter and receiver coupled with a central database, and phase two is comprised of GSM modem with a unique SIM linked to the central data base via GSM network. In the first phase of the system, RF transmitters are tagged to the objects of everyday use and have the capability of transmitting signals, and the paired receiver detects the transmission of the tagged object and stores its corresponding location in the central database, which is created specifically for information maintenance of the tagged objects. In the second phase of the system, a mobile phone is used to query the location of any tagged objects based on its availability in the vicinity, by sending a message to the SIM connected to a GSM modem. If an object is present, the GSM modem fetches the location and other relevant information from the central database and encapsulates this information into a message, which is sent back to the mobile device or phone that has requested the information.
Fuzzy Data Warehouse for Performance Analysis
Authors: Fasel Daniel , Shahzad Khurram
Published: January 2012

The numeric values retrieved from a data warehouse may be difficult to interpret by business users, or may be interpreted incorrectly. Therefore, for more accurate understanding of numeric values, business users may require an interpretation in meaningful, non-numeric terms. However, if the transition between non-numeric terms is crisp, true values cannot be measured, and smooth transition between classes may not take place. To address that problem, the authors employ a fuzzy classification-based approach for data warehouse. For that, they present a fuzzy data warehouse modeling approach, which allows integration of fuzzy concepts without affecting the core of a classical data warehouse. The essence of the approach is that a meta-tables structure is added for relating non-numeric terms with numeric values. This enables integration of fuzzy concepts in dimensions and facts, while preserving the time-invariability of the data warehouse. Additional to that, the use of fuzzy approach allows analysis of data in both sharp and fuzzy manners. The proposed approach is demonstrated through a case study of a movie rental company.
A Fuzzy Segmentation Approach to Guide Marketing Decisions
Authors: Casabayó Mònica , Agell Núria
Published: January 2012

The aim of this chapter is to present a fuzzy segmentation model that combines statistical and Artificial Intelligence techniques to identify and quantify multifaceted consumers. One of the primary challenges faced by companies is getting to know their consumers. The latter are increasingly complex, versatile, ever-changing, and even contradictory; in other words, they are multifaceted. There is thus a need for techniques and tools to be able to segment this type of consumer in order to provide companies with the realistic information they need to make the appropriate marketing decisions. A real case study from the Spanish energy industry is included in this chapter to demonstrate the potential of the segmentation model being proposed.
Causal Recipes Sufficient for Identifying Market Gurus versus Mavens
Authors: Chung Miri , Woodside Arch G.
Published: January 2012

Prior research focusing on the market maven (MM) neglects to consider the possible existence of people who may represent an important source of marketplace information for MMs—the market guru (MG). A “market guru” is a consumer others frequently seek out for advice but who does not seek advice from others. In contrast to MG, a MM is a consumer who other consumers frequently ask for advice and who frequently seeks advice from others. This study raises the proposition that a greater share of MGs versus MMs are innovators, that is, individuals who rely on technical reports to become the first to adopt new products in her or his community. This study applies fuzzy-set qualitative comparative analysis (fs/QCA) to distinguish between MMs and MGs using multi-year data from a national U.S. omnibus survey. The findings support several propositions distinguishing MGs from MMs. MMs evaluate themselves as great influencers of consumers, highly sensitive to normative susceptibility, and possessing superior taste. However, MGs evaluate themselves exactly the opposite from MMs on these conditions.
Designing Visionary Leadership Teams
Authors: Johnson Martin
Published: January 2012

Nigel Sykes’ 3E’s concept is examined against established theory and recent work in Organizational Behaviour. The possibility that this concept offers a way of developing social synergy in work groups is explored, and considered in the context of socio-technical systems. 3E’s is based on the categorisation of people in the workplace into roles labelled “Envisioners” “Enablers” or “Enactors”. Role theory is explored, and its relevance to organizational success. The importance of the affective component in motivation and decision-making is identified. A research study is reported testing the 3E’s concept which shows that it corresponds with measurable differences of motivational need, personality factors, and decision-making between individuals. The characteristics of successful group decision-making are linked with the 3E’s differentiation. The 3E’s model offers the possibility of improving person-role fit, and thus organisational performance. It proposes an integrated design for the selection and operation of teams, offering a person-role fit, optimal decision-making behaviour, and consequent social synergy.
Affective Factors for Successful Knowledge Management
Authors: Smith Peter
Published: January 2012

The article proposes that any effort to successfully manage knowledge must be concerned not only with relevant technology, but also with the plethora of affective factors present in the workforce. The aim of this article is to heighten awareness of the impact of these affective factors on KM implementation, and to offer practical approaches that it is contended will assist in “getting the affective factors right”.
Think Global, Act Local
Authors: Albert Sylvie , Flournoy Don
Published: January 2012

Being able to connect high-speed computing and other information technologies into broadband communication networks presents local communities with some of their best chances for renewal. Such technologies are now widely perceived to be not just a nice amenity among corporations and such non-profit organizations as universities but a social and economic necessity for communities struggling to find their place in a rapidly changing world. Today, citizens want and expect their local communities to be “wired” for broadband digital transactions, whether for family, business, education or leisure. Such networks have become a necessity for attracting and retaining the new “knowledge workforce” that will be key to transforming communities into digital societies where people will want to live and work. Since the Internet is a global phenomenon, some of the challenges of globalization for local communities and regions are introduced in this article and suggestions for turning those challenges into opportunities are offered. To attain maximum benefit from the new wired and wireless networks, local strategies must be developed for its implementation and applications must be chosen with some sensitivity to local needs. New Growth theory is used to show why communities must plan their development agenda, and case studies of the Intelligent Community Forum are included to show how strategically used ICTs are allowing local communities to be contributors in global markets.
Towards a Knowledge-Based Economy – the Case of Botswana
Authors: Bwalya Kelvin Joseph
Published: January 2012

Botswana is keen to position itself as a knowledge-based economy as early as 2016 due to the realisation that to compete on a global scale, efficient knowledge value chains must be put in place, which includes indigenous knowledge management systems. This realisation is primarily caused by falling demand in the price of diamonds (due to the world’s recession), which is the country’s current economic mainstay. Today, Botswana is pushing for further economic liberalisation and diversification by employing and encouraging novel frontiers of knowledge with emphasis placed on research and efficient knowledge management as a vital resource for national development. In Botswana, the role of scientific and technical knowledge is being emphasized as the main driver of sustainable development, but not forgetting the potential contribution of indigenous and mythological knowledge to this aim. Several initiatives have been devised or implemented by both the government and the public sector to position Botswana as a knowledge-based economy. This paper surveys the fundamental concepts on which this paradigm shift is based and brings out the different initiatives that have been undertaken while emphasizing the role of research and efficient knowledge management paradigms in shaping Botswana as a knowledge-based economy.
A Framework for Analyzing Online Communities
Authors: Hunter M. Gordon , Stockdale Rosemary
Published: January 2012

This paper examines online communities and describes how they can be differentiated from other Internet supported group interactions. A definition of an online community is given and three generic types are identified. These types are defined by the community models based on the value proposition for the sponsors and members. The value proposition for members is strongly influenced by the model, as facilities and opportunities for interaction are structured by the site sponsors. Where online communities offer fulfillment of specific needs, people participate and become members. Additional benefits enhance the value of membership and encourage retention and greater interactivity. Significant benefits are gained from online communities for businesses, NGOs, other community organizations and individuals. Identifying the different types of communities and their characteristics is an important stage in developing greater understanding of how virtual communities can contribute to businesses, healthcare, community needs and a myriad of other contexts. Examples of the three generic types of online communities are included for further edification.
Spatialized N budgets in a large agricultural Mediterranean watershed: high loading and low transfer
Authors: Lassaletta L. , Romero E. , Billen G. , Garnier J. , García-Gómez H. , Rovira J. V.
Published: January 2012

Abstract. Despite the particular management practices and climate characteristics of the Mediterranean regions, the literature dealing with N budgets in large catchments subjected to Mediterranean conditions is scarce. The present study aims to deepen our knowledge on the N cycle within the Ebro River Basin (NE Spain) by means of two different approaches: (1) calculating a global N budget in the Ebro River Basin and (2) calculating a series of detailed regional budgets at higher geographical resolution. N inputs and outputs were spatialized by creating a map based on the most detailed information available. Fluvial and atmospheric N export was estimated together with N retention. The Ebro River Basin annually receives a relatively high amount of new N (5118 kg N km−2 yr−1), mostly in the form of synthetic fertilizers (50%). Although it is a highly productive catchment, the net N input as food and feed import is also high (33%). Only 8% of this N is finally exported to the delta zone. Several territorial units characterized by different predominant uses (rainfed agriculture, irrigated agriculture and pastures) have differentiated N dynamics. However, due to the high density of irrigation channels and reservoirs that characterize Mediterranean catchments, N retention is very high in all of them (median value, 91%). These results indicate that problems of eutrophication due to N delivery in the coastal area may not be too severe but that high N retention values may instead lead to problems within the catchment, such as pollution of aquifers and rivers, as well as high atmospheric emissions. The most promising management measures are those devoted to reducing agricultural surpluses through a better balanced N fertilization.
Nitrous oxide emission reduction in temperate biochar-amended soils
Authors: Felber R. , Hüppi R. , Leifeld J. , Neftel A.
Published: January 2012

Abstract. Biochar, a pyrolysis product of organic residues, is an amendment for agricultural soils to improve soil fertility, sequester CO2 and reduce greenhouse gas (GHG) emissions. In highly weathered tropical soils laboratory incubations of soil-biochar mixtures revealed substantial reductions for nitrous oxide (N2O) and carbon dioxide (CO2). In contrast, evidence is scarce for temperate soils. In a three-factorial laboratory incubation experiment two different temperate agricultural soils were amended with green waste and coffee grounds biochar. N2O and CO2 emissions were measured at the beginning and end of a three month incubation. The experiments were conducted under three different conditions (no additional nutrients, glucose addition, and nitrate and glucose addition) representing different field conditions. We found mean N2O emission reductions of 60 % compared to soils without addition of biochar. The reduction depended on biochar type and soil type as well as on the age of the samples. CO2 emissions were slightly reduced, too. NO3– but not NH4+ concentrations were significantly reduced shortly after biochar incorporation. Despite the highly significant suppression of N2O emissions biochar effects should not be transferred one-to-one to field conditions but need to be tested accordingly.
The impact of different glacial boundary conditions on atmospheric dynamics and precipitation in the North Atlantic region
Authors: Hofer D. , Raible C. C. , Dehnert A. , Kuhlemann J.
Published: January 2012

Abstract. Using a highly resolved atmospheric general circulation model the impact of different glacial boundary conditions on precipitation and atmospheric dynamics in the North Atlantic region is investigated. Seven 30-yr time slice experiments of the Last Glacial Maximum (21 ka ago) and of a less pronounced glacial state – the Middle Weichselian (65 ka ago) – are compared to analyse the sensitivity to changes in the ice sheet distribution, in the radiative forcing, and in the prescribed time-varying lower boundary conditions, which are taken from a lower-resolved but fully-coupled atmosphere-ocean general circulation model. The strongest differences are found for simulations with different heights of the Laurentide ice sheet. A large altitude of this ice sheet leads to a southward displacement of the jet stream and the storm track in the North Atlantic region. These changes in the atmospheric dynamics generate a band of increased precipitation in the mid-latitudes across the Atlantic to southern Europe in winter, while the precipitation pattern in summer is only marginally affected. The impact of the radiative forcing differences between the two glacial periods and of the prescribed time-varying lower boundary conditions – evaluated using two simulations of the Last Glacial Maximum with a global mean temperature difference of 1.1 °C – are of second order compared to the one of the Laurentide ice sheet. They affect the atmospheric dynamics and precipitation in a similar but less pronounced manner as the topographic changes.
Extended power-law scaling of air permeabilities measured on a block of tuff
Authors: Siena M. , Guadagnini A. , Riva M. , Neuman S. P.
Published: January 2012

Abstract. We use three methods to identify power-law scaling of multi-scale log air permeability data collected by Tidwell and Wilson on the faces of a laboratory-scale block of Topopah Spring tuff: method of moments (M), Extended Self-Similarity (ESS) and a generalized version thereof (G-ESS). All three methods focus on q-th-order sample structure functions of absolute increments. Most such functions exhibit power-law scaling at best over a limited midrange of experimental separation scales, or lags, which are sometimes difficult to identify unambiguously by means of M. ESS and G-ESS extend this range in a way that renders power-law scaling easier to characterize. Our analysis confirms the superiority of ESS and G-ESS over M in identifying the scaling exponents, ξ(q), of corresponding structure functions of orders q, suggesting further that ESS is more reliable than G-ESS. The exponents vary in a nonlinear fashion with q as is typical of real or apparent multifractals. Our estimates of the Hurst scaling coefficient increase with support scale, implying a reduction in roughness (anti-persistence) of the log permeability field with measurement volume. The finding by Tidwell and Wilson that log permeabilities associated with all tip sizes can be characterized by stationary variogram models, coupled with our findings that log permeability increments associated with the smallest tip size are approximately Gaussian and those associated with all tip sizes scale show nonlinear variations in ξ(q) with q, are consistent with a view of these data as a sample from a truncated version (tfBm) of self-affine fractional Brownian motion (fBm). Since in theory the scaling exponents, ξ(q), of tfBm vary linearly with q we conclude that nonlinear scaling in our case is not an indication of multifractality but an artifact of sampling from tfBm. This allows us to explain theoretically how power-law scaling of our data, as well as of non-Gaussian heavy-tailed signals subordinated to tfBm, are extended by ESS. It further allows us to identify the functional form and estimate all parameters of the corresponding tfBm based on sample structure functions of first and second orders.
Using dissolved oxygen concentrations to determine mixed layer depths in the Bellingshausen Sea
Authors: Castro-Morales K. , Kaiser J.
Published: January 2012

Abstract. Concentrations of oxygen (O2) and other dissolved gases in the oceanic mixed layer are often used to calculate air-sea gas exchange fluxes. The mixed layer depth (zmix) may be defined using criteria based on temperature or density differences to a reference depth near the ocean surface. However, temperature criteria fail in regions with strong haloclines such as the Southern Ocean where heat, freshwater and momentum fluxes interact to establish mixed layers. Moreover, the time scales of air-sea exchange differ for gases and heat, so that zmix defined using oxygen may be different than zmix defined using temperature or density. Here, we propose to define an O2-based mixed layer depth, zmix(O2), as the depth where the relative difference between the O2 concentration and a reference value at a depth equivalent to 10 dbar equals 0.5 %. This definition was established by analysis of O2 profiles from the Bellingshausen Sea (west of the Antarctic Peninsula) and corroborated by visual inspection. Comparisons of zmix(O2) with zmix based on potential temperature differences, i.e., zmix(0.2 °C) and zmix(0.5 °C), and potential density differences, i.e., zmix(0.03 kg m−3) and zmix(0.125 kg m−3), showed that zmix(O2) closely follows zmix(0.03 kg m−3). Further comparisons with published zmix climatologies and zmix derived from World Ocean Atlas 2005 data were also performed. To establish zmix for use with biological production estimates in the absence of O2 profiles, we suggest using zmix(0.03 kg m−3), which is also the basis for the climatology by de Boyer Montégut et al. (2004).
Abnormal Head Position in Infantile Nystagmus Syndrome
Authors: Noval Susana , González-Manrique Mar , Rodríguez-Del Valle José María , Rodríguez-Sánchez José María
Published: January 2012

Infantile nystagmus is an involuntary, bilateral, conjugate, and rhythmic oscillation of the eyes which is present at birth or develops within the first 6 months of life. It may be pendular or jerk-like and, its intensity usually increases in lateral gaze, decreasing with convergence. Up to 64% of all patients with nystagmus also present strabismus, and even more patients have an abnormal head position. The abnormal head positions are more often horizontal, but they may also be vertical or take the form of a tilt, even though the nystagmus itself is horizontal. The aim of this article is to review available information about the origin and treatment of the abnormal head position associated to nystagmus, and to describe our treatment strategies.
Control of Flexible Joint Manipulator via Reduced Rule-Based Fuzzy Control with Experimental Validation
Authors: Rostami Kandroodi Mojtaba , Mansouri Mohammad , Aliyari Shoorehdeli Mahdi , Teshnehlab Mohammad
Published: January 2012

A novel structure of fuzzy logic controller is presented for trajectory tracking and vibration control of a flexible joint manipulator. The rule base of fuzzy controller is divided into two sections. Each section includes two variables. The variables of first section are the error of tip angular position and the error of deflection angle, while the variables of second section are derivatives of mentioned errors. Using these structures, it would be possible to reduce the number of rules. Advantages of proposed fuzzy logic are low computational complexity, high interpretability of rules, and convenience in fuzzy controller. Implementing of the fuzzy logic controller on Quanser flexible joint reveals efficiency of proposed controller. To show the efficiency of this method, the results are compared with LQR method. In this paper, experimental validation of proposed method is presented.
First Principles Study of TiS2/Graphene Heterojunction as Cathode Material for Sodium–Sulfur Batteries
Authors: Long Pan , Zheng Yunxin , Xiao Jianrong , Wang Zhiyong
Published: February 2025

Rechargeable batteries are an indispensable part of the development of environmental sustainability, high capacity and excellent conductivity are essential for optimal energy storage. Sodium–sulfur (Na─S) batteries are recognized as promising options for stationary energy storage solutions, which can be attributed to their high theoretical energy density and cost advantages. Additionally, 2D XS2@graphene heterojunction is considered an excellent host material for batteries. Using the first‐principles calculations, a novel 2D TiS2/graphene heterojunction have been theoretically investigated as an anchoring material for sodium–sulfur batteries to mitigate the shuttle effect. First, the composite structure is created by depositing a TiS2 layer onto a single layer of graphene retains its inherent metallic character. Furthermore, the calculated results show that the TiS2/graphene heterojunction exhibits adsorption energy of 1.3 eV for long‐chain sodium polysulfides while maintaining its metallic properties, effectively anchoring polysulfides and inhibiting the shuttle effect. Moreover, a low diffusion barrier (0.31 eV) for Na ion diffusion shows that this heterojunction can enhance electrochemical processes. TiS2/graphene heterojunction may be the candidate for ideal anchoring materials in sodium–sulfur batteries.
Afterglow Copper(I) Iodine Cluster Scintillator
Authors: Zhao Ying‐Nan , Yang Qi , Yao Bo‐Han , Cao Ruo‐Yu , Zhang Han , Wei Shi‐Long , Wei Dong‐Hui , Li Kai , Si Yu‐Bing , Zang Shuang‐Quan
Published: February 2025

Copper(I) iodine clusters have drawn intense attention due to their advantageous photophysical properties, such as a high luminescence efficiency, large Stokes shift, and tunable luminescence lifetimes. In this work, a copper(I) iodine cluster (Cu2I2‐CH3CN) was synthesized, which exhibits unique afterglow emission, ultrahigh quantum yield (90.1 % in solid state) and aggregation‐induced emission (AIE) behavior. It was found that thermally activated delayed fluorescence (TADF) and long‐lifetime phosphorescence occur simultaneously in Cu2I2‐CH3CN. The unique photoluminescence properties of Cu2I2‐CH3CN were attributed to the large spin‐orbit coupling (SOC) and long‐term rigidity of the crystal. The high quantum efficiency, TADF characteristics, and heavy‐atom composition of Cu2I2‐CH3CN endow it with excellent X‐ray excited luminescence (XEL) properties, making it a promising X‐ray scintillator. A flexible scintillator screen made of Cu2I2‐CH3CN was successfully fabricated and used for X‐ray imaging with a spatial resolution of 23.6 LP mm−1.
Polycyclic Aromatic Hydrocarbons with a Boron‐Doped Zigzag/Armchair Topology: A Boron‐Edging Strategy for Organic Narrowband Emitters
Authors: Tian Xinyu , Fan Zengming , Li Zeyi , Zhang Shitong , Li Zhiqiang , Zhuang Xuming , Wang Yue , Dou Chuandong
Published: February 2025

Control over molecular topologies and/or heteroatom doping of polycyclic aromatic hydrocarbons (PAHs) may alter their electronic structures and achieve desirable physical properties. Herein, this work challenges boron‐doping and edge‐transformation of π‐extended PAHs. We successfully synthesized a series of large‐size PAHs featuring a boron‐doped zigzag/armchair edge topology through one‐pot multifold Scholl cyclization reaction. Two of them possess the desired C3‐symmetric and unexpected unsymmetrical C54B3 nanographene frameworks, respectively, thus illustrating triply boron‐edging manipulations of hexa‐peri‐hexabenzocoronene. Detailed studies reveal that such boron‐doped edge topology significantly inhibits their excited‐state molecular vibrations and thereby produces narrowband emission characteristics. The full width at half maximum (FWHM) values of their fluorescence spectra are as small as 12–18 nm, which have never been observed for pristine boron‐doped π‐system and are among the smallest values reported for organic emitters. Their solution‐processed organic light‐emitting diodes (OLEDs) display extremely narrowband electroluminescence, and additionally, the obtained FWHM of only 23 nm represents the narrowest one reported for red OLEDs.
Synthesis of Functional Pectin‐Based Hydrogels via Thiol‐Maleimide Click Reaction for Enhanced Drug Encapsulation and Release
Authors: Alharbi Hussam Y. , Alnoman Rua B. , Aljohani Majed S. , Monier M.
Published: February 2025

This work describes the synthesis and characterization of a novel hydrogel system based on pectin (PT) functionalized with thiol and maleimide groups and cross‐linked by thiol‐maleimide click chemistry. Thiolated PT (PT‐SH) and maleimide‐modified PT (PT‐Ma) hydrogel precursors were synthesized by carbodiimide‐mediated amidation and confirmed by elemental analysis, FTIR, and 1H NMR spectroscopy. The resulting hydrogel exhibited a gelation efficiency of over 80%, swelling degrees ranging from 44% to 80% depending on cross‐linking density, and pH‐sensitive behavior with maximum swelling at pH 8. The hydrogel demonstrated high mechanical stability, with compressive strengths of 20.8–33.2 kPa, increasing with cross‐linking density. As a model drug, ibuprofen was encapsulated with efficiencies of up to 337 mg/g hydrogel and released in a controlled fashion. In vitro release studies showed a slower release in acidic environments, which ranged from 22% to 53% within 6–10 h, and faster release in a slightly alkaline environment, consistent with the swelling profile of the hydrogel. Such properties underline the hydrogel's potential for sustained drug delivery. Pectin hydrogels, upon thiol‐maleimide cross‐linking, are hereby presented to be a strong platform in biomedical applications based on mechanical properties, swelling behavior, and performance in drug delivery.
High‐Temperature‐Resistant Polyimide Films With Enhanced Tg for Improved Performance in Flexible TFT Devices
Authors: He Dan , Chen Teng , Guo Yuanzheng , Li Guanglan , Liu Xi , Li Chuanyong , Yu Yong , Lan Chuanyan
Published: February 2025

Flexible display devices based on polyimide (PI) materials have found widespread applications in the display industry. However, the lower glass transition temperature (Tg) of PI Films limits the process temperature of low‐temperature poly silica (LTPS), resulting in numerous defects in the thin film transistor (TFT) devices. In this paper, mABZ (meta‐amine benzimidazole) was introduced into the PI film, increasing the Tg of PI from 457°C to 481°C and reducing the thermal expansion coefficient (CTE) to 1.09 ppm, thereby the annealing temperature of TFT could be increased to 480°C. Through the high‐temperature process of LTPS TFT and the innovative use of PI as a substrate, the mobility (Mob) of the TFT devices increased by 49%. This enhancement also led to a 33% rise in the on‐state current (Ion). Additionally, the hysteresis decreased by 0.6 V, and the change in threshold voltage (delta Vth) during negative bias stress measurements reduced by 0.36 V. The introduction of high‐temperature‐resistant PI helps reduce the internal defects of the TFT device during the annealing process. The novel PI materials and the TFT device's corresponding high‐temperature process will help reduce the image sticking of OLED display panels and improve the display stability.