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.

Observation of an Excited B±c Meson State with the ATLAS Detector

Abstract: A search for excited states of the B-c(+/-) meson is performed using 49 fb(-1) of 7 TeV and 192 fb(-1) of 8 TeV pp collision data collected by the ATLAS experiment at the LHC A new state is obse

Comprehensive measurements of t-channel single top-quark production cross sections at √s=7 TeV with the ATLAS detector

Abstract: This article presents measurements of the t-channel single top-quark ((t) over bart) and top-antiquark (_ t) total production cross sections sdtq_ and sd _ tq_, their ratio Rt sdtq_= sd _ tq_, and a measurement of the inclusive production cross section sdtq _ _ tq_ in proton-proton collisions at ffiffiffi ps = 7 TeV at the LHC. Differential cross sections for the tq and _ tq processes are measured as a function of the transverse momentum and the absolute value of the rapidity of t and _ t, respectively. The analyzed data set was recorded with the ATLAS detector and corresponds to an integrated luminosity of 4.59 fb-1. Selected events contain one charged lepton, large missing transverse momentum, and two or three jets. The cross sections are measured by performing a binned maximum-likelihood fit to the output distributions of neural networks. The resulting measurements are sdtq_ 46 = 1dstat_ = 6dsyst_ pb, sd _ tq_ = 23 +/- 1dstat_ = 3dsyst_ pb, Rt = 2.04 0.13dstat_ +/-=0.12dsyst_, and sdtq _ _ tq_ = 68 +/-= 2dstat_ = 8dsyst_ pb, consistent with the Standard Model expectation. The uncertainty on the measured cross sections is dominated by systematic uncertainties, while the uncertainty on Rt is mainly statistical. Using the ratio of sdtq _ _ tq_ to its theoretical prediction, and assuming that the top-quark-related CKM matrix elements obey the relation jVtbj = jVtsj; jVtdj, we determine jVtbj = 1.02 = 0.07.

Hidden transcripts of the gig economy: labour agency and the new art of resistance among African gig workers:

Abstract: In this article, we examine how remote gig workers in Africa exercise agency to earn and sustain their livelihoods in the gig economy. In addition to the rewards reaped by gig workers, they also fa...

Kinetic Evaluation of Dendrimer-Encapsulated Palladium Nanoparticles in the 4-Nitrophenol Reduction Reaction

Abstract: The synthesis of dendrimer-encapsulated palladium nanoparticles with ratios of 13 and 55 metal atoms to templating dendrimer, (Pd13- and Pd55-DENs) was successfully demonstrated with the use of hydroxyl-terminated generation 4 and 5 (G4 and G5) poly(amidoamine) (PAMAM) dendrimers as both templating and stabilizing agents. These Pd-DENs catalysts were fully characterized using spectroscopic techniques. High resolution transmission electron microscopy (HRTEM) was used for the determination of particle size. The average particle sizes were found to be 1.33 ± 0.15 and 1.66 ± 0.20 nm in diameters for Pd13 and Pd55-DENs, respectively. These catalysts were evaluated using the widely utilized model reaction, 4-nitrophenol (NP) reduction by sodium borohydride (NaBH4). The experimentally determined kinetic data was modeled using the Langmuir–Hinshelwood equation which relates the apparent rate kapp, NP and BH4– adsorption constants, KNP and KBH4– respectively, the surface rate constant k, and the surface area, S. T...

Search for squarks and gluinos in final states with jets and missing transverse momentum at √s =13 TeV with the ATLAS detector

Abstract: A search for squarks and gluinos in final states containing hadronic jets, missing transverse momentum but no electrons or muons is presented. The data were recorded in 2015 by the ATLAS experiment ...