Upcycling of mechanically treated silicate mine tailings as alkali activated binders

Abstract Mining activity is inevitable in human societies, and thus, disposal of mining waste in a proper and effective way is crucial to preserving our environment. In this context, studies on the reuse potential for mine tailings in the construction sector are booming. However, utilizing tailings as binder material is complicated due to the high variation in mineralogical composition and the low reactivity of these materials. In this study, an attempt was made to understand the effect of mechanical treatment on silicate mine tailings in order to improve their properties for use as a sole precursor in alkali-activated binders. Two different silicate tailings from Finland were studied: one rich in tremolite, which is high in magnesium (HM tailings) and one rich in anorthite and epidote, which is high in aluminum (HA tailings). Interestingly, grinding activity performed at different durations affected the properties of the tailings with various intensities, including their mineralogical and physical properties and characteristics and, thus the reactivity of tailings. Tremolite does not respond to milling for longer durations, and layered anorthite was easily distorted by the mechanical disturbance. Irrespective of the type of tailings, the compressive strength of alkali-activated milled tailings increased with an increase in grinding time from 1 to 16 min. However, the percentage of compressive strength increase varied with the type of tailings and their mineralogy

Immobilization of sulfates and heavy metals in gold mine tailings by sodium silicate and hydrated lime

Abstract Gold mining produces hazardous tailings wastes with elevated sulfur content and high levels of heavy metals including oxyanion elements such as V and As. This research investigated activation of these tailings with calcium hydroxide and sodium hydroxide/sodium silicate as a way to stabilize the material and limit leaching of harmful components. The effects of thermal treatment on the reactivity of the tailings and the use of different activating solutions on the physical properties, microstructure and leaching of harmful components are reported. The effect of adding ground granulated blast furnace slag to the tailings is also assessed. The use of 5 wt % Ca(OH)₂ activating solution produces optimum performance increasing the immobilization efficiency of sulfates, arsenic and the other harmful elements. Heat-treating mine tailings at 900 °C slightly improves the reactivity but did not improved the immobilization efficiency. Microstructural analysis by TEM and XRD confirmed that stabilization is based on calcium sulfate and/or ettringite formation during alkali-activation. All materials achieved reasonable compressive strength after 28 days of curing and the potential for using alkali activation as a method to treat tailings from mining is discussed

Remote population-based intervention for disruptive behavior at age four: study protocol for a randomized trial of Internet-assisted parent training (Strongest Families Finland-Canada)

Background: Oppositional Defiant Disorder (ODD) is characterized by angry and noncompliant behaviour. It is the most common disruptive behaviour disorder (DBD), with prevalence estimates of 6-9% for preschoolers and is closely linked to several long-term difficulties, including disorders of conduct, mood, anxiety, impulse-control, and substance abuse. ODD in children is related to parental depression, family dysfunction, and impairments in parental work performance. Children displaying early DBDs exhibit more symptoms of greater severity, more frequent offences, and commit more serious crimes later in life. The goal of the Strongest Families™ Finland Canada (SFFC) Smart Website intervention research program is to develop and evaluate an affordable, accessible, effective secondary prevention parent training program for disruptive behaviour in preschoolers to prevent the negative sequelae of ODD. Strongest Families is an 11-session program with two booster sessions that focuses on teaching skills to: strengthen parent–child relationships; reinforce positive behaviour; reduce conflict; manage daily transitions; plan for potentially problematic situations; promote emotional regulation and pro-social behaviour and decrease antisocial behaviour. Methods/design: This protocol paper describes an ongoing population-based randomized controlled trial (RCT) of high-risk 4 year-olds attending well-child clinics in Turku, Finland and environs to examine the effectiveness of the Strongest Families Smart Website intervention compared to an Education Control condition. Randomization consists of a 1:1 ratio for intervention versus the education group, stratified by the child’s sex. The participants randomized to the intervention group receive access to the Strongest Families Smart Website and weekly telephone coaching sessions. The participants randomized to the Education Control condition receive access to a static website with parenting tips. Children are followed using parental and daycare teacher measures at 6 and 12 months after randomization. Discussion: The Strongest Families Smart Website intervention is hypothesized to improve parenting skills, reduce child disruptive behaviour, reduce parental distress and improve family functioning. These results will likely inform subsequent investigations, public policy, and early treatment of childhood disruptive behaviour problems

Madness to the methods:speculating approaches to study and nurture children’s designer and Maker identities

Abstract As our relationship with digital technology radically changes during this pandemic, it becomes imperative to reimagine new ways of interactions and collaborations. It is also important for children grow from passive consumers of digital technology to active designers and Makers. Typical research approaches for inquiring or probing children’s digital technology identities include interview-, reflection-, and hands-on creative-types of methods. But how will these methods fare in a future that is online or hybrid? In this paper, we present the outcomes of a workshop that employed critical design fiction with Child-Computer Interaction experts to speculate on how such methods can be applied in the future, in online or limited access scenarios, to study children’s designer and Maker identities. We focused on approaches that are empowering, albeit provocative. We call for researchers working with children to reconsider and expand their methods repertoire to keep in tune with the changing times

Critical agenda driving child–computer interaction research:taking a stock of the past and envisioning the future

Abstract There is a revitalized interest in power and politics around design and technology in the Human–Computer Interaction (HCI) field. Child–Computer Interaction (CCI) research community has also shown arousing interest towards the topic. However, despite this emerging interest, the CCI research community has remained quite silent about the potential of a critical agenda for CCI. Few studies have explicitly addressed critical research or critical design. This study introduces the notion of a critical agenda for CCI research and identifies CCI studies that are linked with the critical agenda, revealing that there are CCI studies showing emerging interests and seeds for addressing the critical agenda. Overall, this study explores the state-of-the-art critical research tradition in CCI and explicates the potential of this tradition for making the world a better place through design and technology in collaboration with children

All the world is our stage:empowering children to tackle bullying through Theatre of the Oppressed in critical design and making

Abstract Bullying is a serious problem concerning us all. The problem has already been tackled within HCI research, including different design and technology-based interventions, some of which strongly advocate human agency, social responsibility, action taking, and ownership for children. Along these lines, we address the problem of bullying in collaboration with children through critical design and Making. Critical and empowering approaches have aroused interest in child computer interaction (CCI) research, while we particularly explore Theatre of the Oppressed as a tool for evaluating design concepts with children and for empowering children to act as agents of change. Different theatre and drama-based methods have been utilized in CCI, while their potential for empowering children remains poorly explored. This study positions Theatre of the Oppressed within critical design and Making process, examines children’s experiences with it and scrutinizes in which sense it can be considered empowering, with implications for CCI research and design

Nowhere to Now-here:Empowering Children to Reimagine Bully Prevention at Schools Using Critical Design Fiction: Exploring the Potential of Participatory, Empowering Design Fiction in Collaboration with Children

Abstract Bullying is a problem concerning us all, especially our children. Human Computer Interaction (HCI) has invited children to tackle this problem through design and technology. However, yet there is limited research including critical engagement with the topic, even if the critical agenda is arousing increasing interest in HCI. Design fiction has shown potential in addressing critical concerns. However, albeit design fiction has entered HCI method repertoire already some time ago, it is an ambiguous concept with multiple meanings and usages. We map and articulate some of this variety: fascinating, future-oriented, and provocative studies are identified, while also a lack of critical design fiction, aiming at empowerment of the power-weak. We contribute by exploring such kind of design fiction in collaboration with children to tackle the problem of bullying. We scrutinize our participatory and empowering design fiction process and outcomes and discuss their implications for HCI research and design fiction practice

In pursuit of inclusive and diverse digital futures:exploring the potential of design fiction in education of children

Abstract 2020 marks the beginning of a new era as the pandemic catapulted us into new digital and virtual ways of everyday life. As the world changes, we reimagine empowering, equitable, accessible, diverse, and inclusive digital futures, through a series of projects and workshops with a diverse set of participants — children in schools and Child Computer Interaction researchers. We conducted one long-term project with two schools in Finland and two one-day workshops with an international set of participants. Through an analysis of participants’ experiences and outcomes in the project and workshops, we build a case for diversity and inclusion through design fiction in the context of children’s education. In addition, through an analysis of the process we as researchers took for developing the project and workshops, we showcase the support of diversity and inclusion in design fiction