University of Johannesburg

About: University of Johannesburg is a education organization based out in Johannesburg, South Africa. It is known for research contribution in the topics: Population & Context (language use). The organization has 8070 authors who have published 22749 publications receiving 329408 citations. The organization is also known as: UJ.

An overview of renewable energy resources and grid integration for commercial building applications

Abstract: This paper presents an overview of the integration of renewable energy resources in the urban sector. The article also describes the current global energy demand and growth challenges that the world is currently facing. The literature survey on the global energy scenario and renewable energy integration, which mainly involves solar photovoltaic (PV) and battery energy storage systems (BESS), is presented. The paper also addresses the different contexts of using renewable energy resources (RERs) and grid-connected applications. It develops the concept of PV energy storage integration in commercial building applications. Since the common RERs such as wind and solar vary according to seasonal and geographic locations, an outline of the energy storage system that provides a platform for optimal use of RERs is also presented. This structure refers to their ability and dynamic structure that can combine with the renewable power generation to maximise the use of RERs and to ensure the total energy supply to the load. It was observed that the integration of distributed energy resources (DERs) which are connected to the grid is beneficial when the PV and energy storage system (ESS) are smartly mixed with the utility grid. The primary purpose of this energy mix is to assist in improving the dynamic performance of any electrical network operating in a commercial building setup. Thus, this research work analyses the possibility of designing dynamic behaviour for energy management for commercial building applications in South Africa.

Search for chargino-neutralino production using recursive jigsaw reconstruction in final states with two or three charged leptons in proton-proton collisions at √s=13 TeV with the ATLAS detector

Abstract: A search for electroweak production of supersymmetric particles is performed in two-lepton and three-lepton final states using recursive jigsaw reconstruction, a technique that assigns reconstructed objects to the most probable hemispheres of the decay trees, allowing one to construct tailored kinematic variables to separate the signal and background. The search uses data collected in 2015 and 2016 by the ATLAS experiment in s=13 TeV proton-proton collisions at the CERN Large Hadron Collider corresponding to an integrated luminosity of 36.1 fb-1. Chargino-neutralino pair production, with decays via W/Z bosons, is studied in final states involving leptons and jets and missing transverse momentum for scenarios with large and intermediate mass splittings between the parent particle and lightest supersymmetric particle, as well as for the scenario where this mass splitting is close to the mass of the Z boson. The latter case is challenging since the vector bosons are produced with kinematic properties that are similar to those in Standard Model processes. Results are found to be compatible with the Standard Model expectations in the signal regions targeting large and intermediate mass splittings, and chargino-neutralino masses up to 600 GeV are excluded at 95% confidence level for a massless lightest supersymmetric particle. Excesses of data above the expected background are found in the signal regions targeting low mass splittings, and the largest local excess amounts to 3.0 standard deviations. © 2018 CERN, for the ATLAS Collaboration. Published by the American Physical Society.