Herein, the effect of Nb content on the phase transformation kinetics, microstructure, and mechanical properties of hot-rolled quenching and partitioning (Q&P) steel is investigated. The characteristics of three C–Mn–Si–Ti steels (0.18C, 2.0Si, 2.6Mn, and 0.015Ti) containing 0, 0.027, or 0.061 wt% Nb are compared. Results reveal that grain boundary pinning by precipitates and Nb solute drag effects refine the austenite grain size during the hot-rolling process; the microstructural refinement is carried over to the final microstructure subjected to the Q&P treatment. The remaining supersaturated Nb suppresses the bainite formation and decreases the final bainite fraction formed in the Q&P process. The microstructural evolution leads to an increase in the ultimate tensile strength (UTS) of the steel containing 0.027 wt% Nb from 1169 to 1228 MPa, while keeping the total elongation at 18%. When the Nb content is increased to 0.061 wt%, the UTS of the steel increases to 1313 MPa, but the elongation at break drops to 16%. The effect is due to the carbon consumption by the Nb precipitates, which causes a decrease in the stability of the retained austenite and reduces the strain hardening at high strain levels.

In this chapter, we investigate the extent to which the real-time bidirectional exchange of activity information can influence context-awareness, social presence, social connectedness, and importantly interpersonal activity synchrony in mediated ambient assisted living (AAL) environments. Additionally, we describe the design, development, and assessment of a bidirectional ambient display platform to support real-time activity awareness and social connectedness in mediated AAL contexts. In a semi-controlled study, we evaluate a conglomerate of activity-based lighting displays, to determine the effects of real-time bidirectional deployment on behaviour and social connectedness. Exploiting everyday objects, human activity levels are projected with a Philips Hue lamp, LED wallet, and LED walking cane, which render this information based on predefined patterns of light. Results from the current study show tendencies toward (1) an increase in implicit social interactions (e.g., the sense of experienced social presence and connectedness), (2) more positive social behaviours between the elderly and their caregivers in mediated AAL contexts, and (3) sporadic moments of interpersonal activity synchrony however, further investigation is necessary to determine the extent of this variable in mediated AAL contexts.