Minh Tri Luu

Computer-aided design for high efficiency latent heat storage – a case study of a novel domestic solar hot water process

Abstract Latent heat storage (LHS) with high energy storage density and near isotherm operation has emerged as an attractive sustainable alternative to the conventional sensible heat storage. In this paper, a novel domestic solar-assisted hot water (DSHW) process coupled to a LHS module is presented and assessed. Process simulation and sensitivity analyses are carried-out using an in-house 2-D dynamic model of the proposed DSHW. A simulation for a full year shows that with an appropriately customized design, the proposed process consumes about 86% less fossil-fuel compared to a conventional system, demonstrating the superiority of LHS over sensible heat storage in this DSHW application. The examination of the controllability of the system is warranted in order to mitigate the overheating phenomenon. The optimization of the LHS medium properties should be explored to further enhance the efficiency of the process. The current design approach can be implemented for various LHS applications ranging from simple DSHW to the large concentrated solar thermal industrial applications.

Switchable DNA-origami nanostructures that respond to their environment and their applications

Structural DNA nanotechnology, in which Watson-Crick base pairing drives the formation of self-assembling nanostructures, has rapidly expanded in complexity and functionality since its inception in 1981. DNA nanostructures can now be made in arbitrary three-dimensional shapes and used to scaffold many other functional molecules such as proteins, metallic nanoparticles, polymers, fluorescent dyes and small molecules. In parallel, the field of dynamic DNA nanotechnology has built DNA circuits, motors and switches. More recently, these two areas have begun to merge—to produce switchable DNA nanostructures, which change state in response to their environment. In this review, we summarise switchable DNA nanostructures into two major classes based on response type: molecular actuation triggered by local chemical changes such as pH or concentration and external actuation driven by light, electric or magnetic fields. While molecular actuation has been well explored, external actuation of DNA nanostructures is a relatively new area that allows for the remote control of nanoscale devices. We discuss recent applications for DNA nanostructures where switching is used to perform specific functions—such as opening a capsule to deliver a molecular payload to a target cell. We then discuss challenges and future directions towards achieving synthetic nanomachines with complexity on the level of the protein machinery in living cells.