Influence of annealing on microstructure and mechanical properties of ultrafine-grained Ti45Nb

Beta-Ti alloys have been intensively investigated in the last years because of their favorable low Young's moduli, biocompatibility and bio-inertness, making these alloys interesting candidates for implant materials. Due to their low mechanical strength, efforts are currently devoted to increasing it. A promising way to improve the strength is to tailor the microstructure using severe plastic deformation (SPD). In this investigation high pressure torsion was used to refine the microstructure of a Ti-45wt.%Nb alloy inducing a grain size of ~50 nm. The main focus of the subsequent investigations was devoted to the thermal stability of the microstructure. Isochronal heat-treatments performed for 30 min in a temperature range up to 500 °C caused an increase of hardness with a peak value at 300 °C before the hardness decreased at higher temperatures. Simultaneously, a distinct temperature-dependent variation of the Young's modulus was also measured. Tensile tests revealed an increase in strength after annealing compared to the SPD-state. Microstructural investigations showed that annealing causes the formation of α-Ti. The findings suggest that the combination of severe plastic deformation with subsequent heat treatment provides a feasible way to improve the mechanical properties of SPD-deformed β-Ti alloys making them suitable for higher strength applications

On the application of blockchains to spectrum management

Spectrum sharing mechanisms have evolved to meet different needs related to increasing spectrum use efficiency. At first, decentralized and opportunistic cognitive radios (and cognitive radio networks) were the primary focus of research for these mechanisms. This gradually transitioned toward the development of cooperative sharing methods based on databases, typified by TV white spaces databases. Spectrum sharing is now the basis for the dynamic and fine-grained spectrum rights regime for the citizen's band radio service (CBRS) as well as for license shared access (LSA). The emergence of the cryptocurrency Bitcoin has stimulated interest in applying its underlying technology, blockchain, to other applications as well, such as securities trading and supply chain management. This paper explores the application of blockchain to radio spectrum management. While blockchains could underlie radio spectrum management more broadly, we will focus on dynamic spectrum sharing applications. Like the cooperative approaches currently in use, blockchain is a database technology. However, a blockchain is a decentralized database in which the owner of the data maintains control. We consider the benefits and limitations of blockchain solutions in general, and then examine their potential application to four major categories of spectrum sharing

Gamification and Adherence to Web-Based Mental Health Interventions: A Systematic Review

Background: Adherence to effective Web-based interventions for common mental disorders (CMDs) and well-being remains a critical issue, with clear potential to increase effectiveness. Continued identification and examination of “active” technological components within Web-based interventions has been called for. Gamification is the use of game design elements and features in nongame contexts. Health and lifestyle interventions have implemented a variety of game features in their design in an effort to encourage engagement and increase program adherence. The potential influence of gamification on program adherence has not been examined in the context of Web-based interventions designed to manage CMDs and well-being. Objective: This study seeks to review the literature to examine whether gaming features predict or influence reported rates of program adherence in Web-based interventions designed to manage CMDs and well-being. Methods: A systematic review was conducted of peer-reviewed randomized controlled trials (RCTs) designed to manage CMDs or well-being and incorporated gamification features. Seven electronic databases were searched. Results: A total of 61 RCTs met the inclusion criteria and 47 different intervention programs were identified. The majority were designed to manage depression using cognitive behavioral therapy. Eight of 10 popular gamification features reviewed were in use. The majority of studies utilized only one gamification feature (n=58) with a maximum of three features. The most commonly used feature was story/theme. Levels and game leaders were not used in this context. No studies explicitly examined the role of gamification features on program adherence. Usage data were not commonly reported. Interventions intended to be 10 weeks in duration had higher mean adherence than those intended to be 6 or 8 weeks in duration. Conclusions: Gamification features have been incorporated into the design of interventions designed to treat CMD and well-being. Further research is needed to improve understanding of gamification features on adherence and engagement in order to inform the design of future Web-based health interventions in which adherence to treatment is of concern. Conclusions were limited by varied reporting of adherence and usage dat

Gamifying self-management of chronic illnesses: amixed-methods study

Background: Self-management of chronic illnesses is an ongoing issue in health care research. Gamification is a concept that arose in the field of computer science and has been borrowed by many other disciplines. It is perceived by many that gamification can improve the self-management experience of people with chronic illnesses. This paper discusses the validation of a framework (called The Wheel of Sukr) that was introduced to achieve this goal.Objective: This research aims to (1) discuss a gamification framework targeting the self-management of chronic illnesses and (2) validate the framework by diabetic patients, medical professionals, and game experts.Methods: A mixed-method approach was used to validate the framework. Expert interviews (N=8) were conducted in order to validate the themes of the framework. Additionally, diabetic participants completed a questionnaire (N=42) in order to measure their attitudes toward the themes of the framework.Results: The results provide a validation of the framework. This indicates that gamification might improve the self-management of chronic illnesses, such as diabetes. Namely, the eight themes in the Wheel of Sukr (fun, esteem, socializing, self-management, self-representation, motivation, growth, sustainability) were perceived positively by 71% (30/42) of the participants with P value <.001.Conclusions: In this research, both the interviews and the questionnaire yielded positive results that validate the framework (The Wheel of Sukr). Generally, this study indicates an overall acceptance of the notion of gamification in the self-management of diabete

Smart, social, flexible and fun: Escaping the flatlands of virtual learning environments

© 2019, Springer Nature Switzerland AG. This paper describes the development of intelligent, social, flexible and game-based pedagogic approaches and their applications in Virtual Learning Environment based Education. Applications of computer science technologies and techniques can enable, facilitate and change educational approaches, allowing scalable approaches that can address both individual student needs whilst managing large – sometimes-massive - cohort sizes. The benefits of these information systems include supporting the wide range of contexts met in education, in terms of individual needs and specific subject and curriculum requirements. Technologies and approaches that are considered range from the representation of knowledge and the use of intelligent systems, the use of social computing, through to the enabling opportunities of ubicomp and the practical application of game mechanics (gamification). This paper concludes with practical illustrations in the context of undergraduate computer science didactics

Mindergie: A pervasive learning game for pro-environmental behaviour at the workplace

This chapter reports about a pervasive learning game to increase the environmental awareness and pro-environmental behaviour at the workplace. Based on a discussion of the theoretical background and related work we introduce the game design and game elements. Results of a formative evaluation study are presented and discussed. Results show that incentive mechanisms are less important than challenging game components that involve employees in proposing solutions for energy conservation at the workplace. Conclusions are drawn for future games and energy conservation activities at the workplace.This project has been partially funded by a SURFnet innovation grant for sustainable ICT solutions and partially by the Welten Institute – Research Centre for Learning, Teaching and Technology of the Open University of the Netherlands

Crowdcloud: A Crowdsourced System for Cloud Infrastructure

The widespread adoption of truly portable, smart devices and Do-It-Yourself computing platforms by the general public has enabled the rise of new network and system paradigms. This abundance of wellconnected, well-equipped, affordable devices, when combined with crowdsourcing methods, enables the development of systems with the aid of the crowd. In this work, we introduce the paradigm of Crowdsourced Systems, systems whose constituent infrastructure, or a significant part of it, is pooled from the general public by following crowdsourcing methodologies. We discuss the particular distinctive characteristics they carry and also provide their “canonical” architecture. We exemplify the paradigm by also introducing Crowdcloud, a crowdsourced cloud infrastructure where crowd members can act both as cloud service providers and cloud service clients. We discuss its characteristic properties and also provide its functional architecture. The concepts introduced in this work underpin recent advances in the areas of mobile edge/fog computing and co-designed/cocreated systems

Motivational gamification strategies rooted in self-determination theory for social adaptive E-Learning.

This study uses gamification as the carrier of understanding the motivational benefits of applying the Self-Determination Theory (SDT) in social adaptive e-learning, by proposing motivational gamification strategies rooted in SDT, as well as developing and testing these strategies. Results show high perceived motivation amongst the students, and identify a high usability of the implementation, which supports the applicability of the proposed approach

Pervasive interventions to increase pro-environmental awareness, consciousness, and learning at the workplace

Börner, D., Kalz, M., Ternier, S., & Specht, M. (2013). Pervasive interventions to increase pro-environmental awareness, consciousness, and learning at the workplace. In D. Hernández-Leo et al. (Eds.), Scaling up Learning for Sustained Impact. Proceedings of the 8th European Conference on Technology Enhanced Learning (EC-TEL 2013), LNCS 8095 (pp. 57-70). Berlin Heidelberg, Germany: Springer. [The final publication is available at link.springer.com/chapter/10.1007/978-3-642-40814-4_6]This paper reports about pervasive interventions at a university campus to increase the pro-environmental awareness, consciousness, and learning of employees. Based on an assessment of the research gaps in this problem area we present results and design implications from three intervention iterations. While in the first intervention the focus was on increasing awareness through information distribution with ambient learning displays on the campus, the second iteration provided personalised feedback to employees with the help of a sensor network and different client applications. The third iteration then implemented a game-based learning concept. Results reveal that these approaches are effective on different levels and that a combination of these elements can lead to increased pro-environmental consciousness, learning and hopefully a sustained behaviour change of employees.SURFnet Innovatieregeling Duurzaamheid & IC