Contaminant Intrusion through Leaks in Water Distribution System: Experimental Analysis

This paper presents the results of experimental tests on the intrusion of contaminant through pipe cracks in water distribution network resulting from low/negative pressures. The tests were carried out on a looped distribution network at the University of Enna and were performed first producing a pressure transient that causes negative pressures then reproducing intermittent supply. A soluble contaminant was added to the water volume in the network through a pipe crack. Sampling of water volume was carried out in two nodes of the network and the contaminant concentrations were measured. It was showed that: the contaminant was drawn in and transported, in the first set of tests; the contaminant was carried through the network to the point-of-use when the pipes become completely full and the distribution system was in steady state conditions, in the second, and that the concentrations was higher than in the first set of test

0D-1D hybrid silicon nanocomposite as lithium-ion batteries anodes

Lithium ion batteries (LIBs) are the enabling technology for many of the societal changes that are expected to happen in the following years. Among all the challenges for which LIBs are the key, vehicle electrification is one of the most crucial. Current battery materials cannot provide the required power densities for such applications and therefore, it makes necessary to develop new materials. Silicon is one of the proposed as next generation battery materials, but still there are challenges to overcome. Poor capacity retention is one of those drawbacks, and because it is tightly related with its high capacity, it is a problem rather difficult to address with common and scalable fabrication processes. Here we show that combining 0D and 1D silicon nanostructures, high capacity and stability can be achieved even using standard electrode fabrication processes. Capacities as high as 1200 mAh/g for more than 500 cycles at high current densities (2 A/g) were achieved with the produced hybrid 0D/1D electrodes. In this research, it was shown that while 0D nanostructures provide good strain relaxation capabilities, 1D nanomaterials contribute with enhanced cohesion and conductive matrix integrityThis research was funded by the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 713567 and Science Foundation Irelands Research Centre award 12/RC/2278_P2. This work was supported by the Ministerio de Economía y Competitividad (MINECO) of Spain, under Grant ENE2014-57977-C2-1-R and “Estancias de Movilidad Salvador Madariaga”. Financial support from the U.S. Department of Defense (grant W911NF-14-1-0046), and from the U.S. Department of Energy, through the Consortium for Integrating Energy Systems in Engineering and Science Education, CIESESE (DE-NA0003330) is also acknowledge

Controlled Fabrication of Native Ultra-Thin Amorphous Gallium Oxide From 2D Gallium Sulfide for Emerging Electronic Applications

Oxidation of 2D layered materials has proven advantageous in creating oxide/2D material heterostructures, opening the door for a new paradigm of low-power electronic devices. Gallium (II) sulfide (β-GaS), a hexagonal phase group III monochalcogenide, is a wide bandgap semiconductor with a bandgap exceeding 3 eV in single and few-layer form. Its oxide, gallium oxide (Ga2O3), combines a large bandgap (4.4–5.3 eV) with a high dielectric constant (≈10). Despite the technological potential of both materials, controlled oxidation of atomically-thin β-GaS remains under-explored. This study focuses on the controlled oxidation of β-GaS using oxygen plasma treatment, addressing a significant gap in existing research. The results demonstrate the ability to form ultrathin native oxide (GaSxOy), 4 nm in thickness, upon exposure to 10 W of O2, resulting in a GaSxOy/GaS heterostructure where the GaS layer beneath remains intact. By integrating such structures between metal electrodes and applying electric stresses as voltage ramps or pulses, their use for resistive random-access memory (ReRAM) is investigated. The ultrathin nature of the produced oxide enables low operation power with energy use as low as 0.22 nJ per operation while maintaining endurance and retention of 350 cycles and 104 s, respectively. These results show the significant potential of the oxidation-based GaSxOy/GaS heterostructure for electronic applications and, in particular, low-power memory devices

A new semiconducting perovskite alloy system made possible by gas-source molecular beam epitaxy

We demonstrate epitaxial thin film growth of the chalcogenide perovskite semiconducting alloy system BaZrS$_{(3-y)}$Se$_y$ using gas-source molecular beam epitaxy (MBE). BaZrS$_3$ is stable in the perovskite structure in bulk form, but the pure selenide BaZrSe$_3$ is not. Here stabilize the full range of compositions y = 0 ... 3 in the perovskite structure, up to and including BaZrSe$_3$, by growing on BaZrS$_3$ buffer layers. The alloy grows by pseudomorphic heteroepitaxy on the sulfide buffer, without interruption in the reflection high energy electron diffraction (RHEED) pattern. The resulting films are environmentally stable and the direct band gap (E$_g$) varies strongly with Se content, as predicted by theory, covering the range E$_g$ = 1.9 ... 1.4 eV for y = 0 ... 3. This creates possibilities for visible and near-infrared (VIS-NIR) optoelectronics, solid state lighting, and solar cells using chalcogenide perovskites

MXene materials based printed flexible devices for healthcare, biomedical and energy storage applications

The advent of cost effective printed smart devices has revolutionized the healthcare sector by allowing disease prediction and timely treatment through non-invasive real time and continuous health monitoring. Future advancements in printed electronic (PE) materials will continue to enhance the quality of human living. For any PE application, materials should possess proper mechanical integrity and resistivity while being non-toxic. In the case of sensing devices for physiological and biochemical signals, excellent conductivity is an essential requirement for obtaining high response signals. The emergence of the novel class of 2D materials called MXenes and their composites has resulted in structures and materials hugely relevant for healthcare devices. Exploiting solution based 2D MXene materials can expedite their practical application in PE devices by overcoming the present limitations of conductive inks such as poor conductivity and the high cost of alternative functional inks. There has been much progress in the MXene functional ink generation and its PE device applications since its discovery in 2011. This review summarizes the MXene ink formulation for additive patterning and the development of PE devices enabled by them in healthcare, biomedical and related power provision applications

Solvent Engineered Synthesis of Layered SnO Nanoparticles for High-Performance Anodes

Batteries are the most abundant form of electrochemical energy storage. Lithium and sodium ion batteries account for a significant portion of the battery market, but high-performance electrochemically active materials still need to be discovered and optimized for these technologies. Recently, tin(II) oxide (SnO) has emerged as a highly-promising battery electrode. In this work, we present a facile synthesis method to produce SnO nanoparticles whose size and shape can be tailored by changing the solvent nature. We study the complex relationship between wet chemistry synthesis conditions and resulting layered nanoparticle morphology. Furthermore, high-level electronic structure theory, including dispersion corrections to account for van der Waals forces, are employed to enhance our understanding of the underlying chemical mechanisms. The electronic vacuum alignment and surface energies are determined, allowing the prediction of the thermodynamically-favoured crystal shape (Wulff construction) and surface-weighted work function. Finally, the synthesized nanomaterials were tested as Li-ion battery anodes, demonstrating significantly enhanced electrochemical performance for morphologies obtained from specific synthesis conditions