System Design of Internet-of-Things for Residential Smart Grid

Internet-of-Things (IoTs) envisions to integrate, coordinate, communicate, and collaborate real-world objects in order to perform daily tasks in a more intelligent and efficient manner. To comprehend this vision, this paper studies the design of a large scale IoT system for smart grid application, which constitutes a large number of home users and has the requirement of fast response time. In particular, we focus on the messaging protocol of a universal IoT home gateway, where our cloud enabled system consists of a backend server, unified home gateway (UHG) at the end users, and user interface for mobile devices. We discuss the features of such IoT system to support a large scale deployment with a UHG and real-time residential smart grid applications. Based on the requirements, we design an IoT system using the XMPP protocol, and implemented in a testbed for energy management applications. To show the effectiveness of the designed testbed, we present some results using the proposed IoT architecture.Comment: 10 pages, 6 figures, journal pape

Effect of interfacial heat transfer on the onset of oscillatory convection in liquid bridge

International audienceIn present study, effect of interfacial heat transfer with ambient gas on the onset of oscillatory convection in a liquid bridge of large Prandtl number on the ground is systematically investigated by the method of linear stability analyses. With both the constant and linear ambient air temperature distributions, the numerical results show that the interfacial heat transfer modifies the free-surface temperature distribution directly and then induces a steeper temperature gradient on the middle part of the free surface, which may destabilize the convection. On the other hand, the interfacial heat transfer restrains the temperature disturbances on the free surface, which may stabilize the convection. The two coupling effects result in a complex dependence of the stability property on the Biot number. Effects of melt free-surface deformation on the critical conditions of the oscillatory convection were also investigated. Moreover, to better understand the mechanism of the instabilities, rates of kinetic energy change and ''thermal " energy change of the critical disturbances were investigate

1-{(1Z)-1-[6-(4-Chloro­phen­oxy)hex­y­l­oxy]-1-(2,4-difluoro­phen­yl)prop-1-en-2-yl}-1H-1,2,4-triazol-4-ium nitrate

In the title compound, C23H25ClF2N3O2 +·NO3 −, the triazole ring makes dihedral angles of 60.9 (4) and 25.0 (3)° with the 6-chloro­phenyl and 2,4-difluoro­phenyl rings, respectively. The mol­ecule adopts a Z configuration about the C=C double bond. In the crystal, the cations and anions are linked by N—H⋯O hydrogen bonds and weak C—H⋯O inter­actions

Mechanical Self-Assembly Technology for 2D Materials

Self-assembled mechanical instabilities can offer a new technology roadmap for micro/nanopatterns of two-dimensional (2D) materials, which depends on the deterministic regulation of mechanical instability-induced self-assemblies. However, due to atomic thinness and ultra-low bending stiffness, different types of non-designable and non-deterministic multimode coupling mechanical instabilities, such as multimode-coupled crumpling, chaotic thermal-fluctuation-induced rippling, and unpredictable wrinkling, are extremely easy to be triggered in 2D materials. The above mode-coupled instabilities make it exceedingly difficult to controllably self-assemble 2D nanocrystals into designed morphologies. In this chapters, we will introduce a novel micro/nanopatterning technology of 2D materials based on mechanical self-assemblies. Firstly, a post-curing transfer strategy is proposed to fabricate multiscale conformal wrinkle micro/nanostructures of 2D materials. Secondly, we report a deterministic self-assembly for programmable micro/nanopatterning technology of atomically thin 2D materials via constructing novel 2D materials/IML/substrate trilayer systems. Finally, based on the micro/nanopatterning technology of 2D materials, we proposed a new fabrication method for the flexible micro/nano-electronics of deterministically self-assembled 2D materials including three-dimensional (3D) tactile and gesture sensors. We fundamentally overcome the key problem of self-assembly manipulation from randomness to determinism mode by decoupling mono-mode mechanical instability, providing new opportunities for programmable micro/nanopatterns of 2D materials. Moreover, mechanical instability-driven micro/nanopatterning technology enables simpler fabrication methods of self-assembled electronics based on 2D materials

1,2-Bis(4-methyl­phen­oxy)ethane

In the title compound, C16H18O2, the two aromatic rings are almost orthogonal, making a dihedral angle of 89.41 (2)°. There is a C—H⋯π contact between the methyl­ene group and the 4-methyl­phenyl ring. The molecule exhibits twofold symmetry.