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.

Compressive strength of circular concrete filled steel tube columns

Abstract: An experimental study was undertaken to investigate the behaviour of 24 concrete-filled steel tube (CFST) columns, loaded concentrically in compression to failure. Variables in the tests include the length, diameter, strength of the steel tubes and the strength of the concrete. The large slenderness ratio caused all composite columns in Series 1 to fail by overall flexural buckling. Although overall flexural buckling was also experienced in the composite columns of Series 2 tests, the stockier columns failed by crushing of the concrete and yielding of the steel tube. A comparison of the experimental results with the loads predicted by the South African code (SANS 10162-1) and Eurocode 4 (EC4) shows that the codes are conservative by 8.4% and 13.6%, respectively, for Series 1 tests, and 10.5 and 20.2%, respectively, for Series 2 tests. A plot of the compressive load versus the vertical deflection shows the composite columns to be fairly ductile.

Search for resonances decaying into top-quark pairs using fully hadronic decays in pp collisions with ATLAS at √s=7 TeV

Abstract: A search for resonances produced in 7 TeV proton-proton collisions and decaying into top-quark pairs is described. In this Letter events where the top-quark decay produces two massive jets with large transverse momenta recorded with the ATLAS detector at the Large Hadron Collider are considered. Two techniques that rely on jet substructure are used to separate top-quark jets from those arising from light quarks and gluons. In addition, each massive jet is required to have evidence of an associated bottom-quark decay. The data are consistent with the Standard Model, and limits can be set on the production cross section times branching fraction of a Z′ boson and a Kaluza-Klein gluon resonance. These limits exclude, at the 95% credibility level, Z′ bosons with masses 0.70-1.00 TeV as well as 1.28-1.32 TeV and Kaluza-Klein gluons with masses 0.70-1.62 TeV.

“Couchsurfing has made me a better person and the world a better place”: the transformative power of collaborative tourism experiences

Abstract: Presented as an alternative form of tourism, Couchsurfing is a predominantly non-commercial accommodation type where hosts offer a “couch” to travelers through a hospitality network. Couchsurfing.com is considered as an icon of the sharing economy and more specifically of shareable tourism. This article provides a deeper understanding of couchsurfers’ motivations and shared values. Through an empirical qualitative study, we discuss the transformative power of Couchsurfing experiences, the underlying transformational processes, conditions, and socio-psychological and behavioral consequences. We also discuss the findings’ implications for society, businesses, and tourism in general.

Search for dark matter produced in association with bottom or top quarks in s=13 TeV pp collisions with the ATLAS detector.

Abstract: A search for weakly interacting massive dark matter particles produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and missing transverse ...