Microstructure design using graphs

Thin films with tailored microstructures are an emerging class of materials with applications such as battery electrodes, organic electronics, and biosensors. Such thin film devices typically exhibit a multi-phase microstructure that is confined, and show large anisotropy. Current approaches to microstructure design focus on optimizing bulk properties, by tuning features that are statistically averaged over a representative volume. Here, we report a tool for morphogenesis posed as a graph-based optimization problem that evolves microstructures recognizing confinement and anisotropy constraints. We illustrate the approach by designing optimized morphologies for photovoltaic applications, and evolve an initial morphology into an optimized morphology exhibiting substantially improved short circuit current (68% improvement over a conventional bulk-heterojunction morphology). We show optimized morphologies across a range of thicknesses exhibiting self-similar behavior. Results suggest that thicker films (250 nm) can be used to harvest more incident energy. Our graph based morphogenesis is broadly applicable to microstructure-sensitive design of batteries, biosensors and related applications

Introduction Studies of Plasma-Focus discharges within the PF-360 facility equipped with needle D 2 O-ice target

Numerous PF experiments, which were performed in many laboratories all over the world showed a promising scaling of the neutron yield (Y n ) from D-D fusion reactions. Some investigations extended this scaling to a multi-MJ and multi-MA level Experimental set-up Recent studies within the PF-360 facility have been carried out by using larger coaxial electrodes of 120 mm and 170 mm in diameter, respectively. Both electrodes were 300 mm in length, and the main ceramic insulator, embracing the basis of the inner electrode, was 80 mm in length. The main experimental chamber of the PF-360 facility was filled with pure deuterium under the initial pressure, which was varied from 5.1 mbar to 12.0 mbar. PF discharges were powered from a capacitor bank of 288 µF. Abstract The paper describes a new technique which has been investigated in order to overcome the neutron saturation effect and to increase the neutron yield from the plasma-focus (PF) discharge

M (2000) Studies of Plasma-Focus discharges within the PF-360 facility equipped with a planar D2O-ice target. Nukleonika 46;S1:65–68 37Results of large scale Plasma-Focus experiments and prospects for neutron yield optimization

Introduction Many Plasma-Focus (PF) experiments, which were performed in different laboratories, showed an optimistic scaling of the neutron emission. These scaling laws for the fusion neutron yield (Y n ) from the Plasma-Focus facilities are described by the simple formulae: where W 0 is the initial energy input, I max is the maximum value of the main discharge current, α = 2.0-2.2 as well as β = 3.3-4.4 depend on a machine type and input energy value. For the PF-360 facility There were some papers, which suggested that it is possible to extend this scaling to a higher discharge current and initial energy values [1], but there is no experimental verification of this hypothesis so far. On the contrary, it was found that the promising scaling laws are valid only up to some critical levels, at which the neutron yield saturates (or even decreases) The PF-360 machine was built during the turn of the 70s and 80

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Abstract The paper describes experimental studies of Plasma-Focus (PF) discharges carried out within the modernized PF-360 facility, which was operated with an additional D 2 -gas puffing into the region of the collapsing current sheath and PF pinch formation, i.e. into space in front of the electrode outlet. The main aim of these studies was to increase a neutron yield from PF discharges by using fast deuteron beams, which are usually emitted from a pinch column and which can interact with additional D 2 -gas target

Microstructure design using graphs

Thin films with tailored microstructures are an emerging class of materials with applications such as battery electrodes, organic electronics, and biosensors. Such thin film devices typically exhibit a multi-phase microstructure that is confined, and show large anisotropy. Current approaches to microstructure design focus on optimizing bulk properties, by tuning features that are statistically averaged over a representative volume. Here, we report a tool for morphogenesis posed as a graph-based optimization problem that evolves microstructures recognizing confinement and anisotropy constraints. We illustrate the approach by designing optimized morphologies for photovoltaic applications, and evolve an initial morphology into an optimized morphology exhibiting substantially improved short circuit current (68% improvement over a conventional bulk-heterojunction morphology). We show optimized morphologies across a range of thicknesses exhibiting self-similar behavior. Results suggest that thicker films (250 nm) can be used to harvest more incident energy. Our graph based morphogenesis is broadly applicable to microstructure-sensitive design of batteries, biosensors and related applications.This article is published as Du, Pengfei, Adrian Zebrowski, Jaroslaw Zola, Baskar Ganapathysubramanian, and Olga Wodo. "Microstructure design using graphs." npj Computational Materials 4, no. 1 (2018): 50. DOI: 10.1038/s41524-018-0108-5. Posted with permission. </p