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In a crystalline solid under mechanical stress, a Frank-Read source is a pinned dislocation segment that repeatedly bows and detaches, generating concentric dislocation loops. We demonstrate that, in nematic liquid crystals, an analogous Frank-Read mechanism can generate concentric disclination loops. Using experiment, simulation, and theory, we study a disclination segment pinned between surface defects on one substrate in a nematic cell. Under applied twist of the nematic director, the pinned segment bows and emits a new disclination loop which expands, leaving the original segment intact; loop emission repeats for each additional 180° of applied twist. We present experimental micrographs showing loop expansion and snap-off, numerical simulations of loop emission under both quasistatic and dynamic loading, and theoretical analysis considering both free energy minimization and the balance of competing forces. We find that the critical stress for disclination loop emission scales as the inverse of segment length and changes as a function of strain rate and temperature, in close analogy to the Frank-Read source mechanism in crystals. Lastly, we discuss how Frank-Read sources could be used to modify microstructural evolution in both passive and active nematics. 

Architectural, Engineering, and Construction (AEC) project team networks frequently increase the density of information sharing ties to improve team performance. However, increased density might not result in team members receiving adequate in-formation to collaborate towards common goals. There is a need to examine how net-work ties should be set up to manage information flows. Thus, the research goal is to explore the features of information sharing networks and their relationship with team performance in AEC projects. To achieve this goal, we collected communication data from an AEC project team with 179 members involved in total during the schematic design phase. Then, we performed social network analysis using Gephi and UCINET software. Results suggest that AEC project team networks are dynamic and adopt a core-periphery structure to share information early in project delivery. Including civil and mechanical subcontractors into the core subnetwork to collaborate with owners, designers, and general contractors can improve team performance. The study’s contribution to the body of knowledge is expanding our understanding of the characteristics and evolution of information sharing networks in AEC projects for optimized team performance.