The state of transport opinion poll: gauteng 2021

Transport is a major concern for South Africans and remains a constraint to the livelihoods of many people. Concerns range from the state of road, rail and facility infrastructure and service levels of public transport to e-tolls and law enforcement. The Institute of Transport and Logistics Studies has revived its annual State of Transport Opinion Poll to provide a comprehensive perspective on the transport issues that are faced by Gauteng residents. A survey of 521 respondents was conducted to gauge their opinions on transport-related matters. Previous polls (2012-2015) were used as a base for comparison. The study found a major dampening of enthusiasm regarding the state of transport, both country-wide and in their local areas, with most people believing that improvements are unlikely in the near future. Major issues continue to be the poor state of public transport services, the worsening condition of road infrastructure, and weak law enforcement. Gauteng residents also indicated that the public transport service providers did not sufficiently adhere to COVID-19 protocols. By implication, the commuting public faces insufficient, poor-quality services, where people are left vulnerable to crime, accidents, and illness. This information could be of value to policymakers by expanding on household travel data to add to the database of opinions and concerns about a broad range of transport-related issuesPapers presented at the 40th International Southern African Transport Conference on 04 -08 July 202

Absence of static magnetic order in lightly-doped Ti1-xScxOCl down to 1.7 K

Impurity-induced magnetic order has been observed in many quasi-1D systems including doped variants of the spin-Peierls system CuGeO3. TiOCl is another quasi-1D quantum magnet with a spin-Peierls ground state, and the magnetic Ti sites of this system can be doped with non-magnetic Sc. To investigate the role of non-magnetic impurities in this system, we have performed both zero field and longitudinal field muSR experiments on polycrystalline Ti1-xScxOCl samples with x = 0, 0.01, and 0.03. We verified that TiOCl has a non-magnetic ground state, and we found no evidence for spin freezing or magnetic ordering in the lightly-doped Sc samples down to 1.7 K. Our results instead suggest that these systems remain non-magnetic up to the x = 0.03 Sc doping level.Comment: 5 pages, 4 figure

4D, N = 1 Supersymmetry Genomics (I)

Presented in this paper the nature of the supersymmetrical representation theory behind 4D, N = 1 theories, as described by component fields, is investigated using the tools of Adinkras and Garden Algebras. A survey of familiar matter multiplets using these techniques reveals they are described by two fundamental valise Adinkras that are given the names of the cis-Valise (c-V) and the trans-Valise (t-V). A conjecture is made that all off-shell 4D, N = 1 component descriptions of supermultiplets are associated with two integers - the numbers of c-V and t-V Adinkras that occur in the representation.Comment: 53 pages, 19 figures, Report-II of SSTPRS 2008 Added another chapter for clarificatio

Exclusion limits on the WIMP-nucleon cross-section from the Cryogenic Dark Matter Search

The Cryogenic Dark Matter Search (CDMS) employs low-temperature Ge and Si detectors to search for Weakly Interacting Massive Particles (WIMPs) via their elastic-scattering interactions with nuclei while discriminating against interactions of background particles. For recoil energies above 10 keV, events due to background photons are rejected with >99.9% efficiency, and surface events are rejected with >95% efficiency. The estimate of the background due to neutrons is based primarily on the observation of multiple-scatter events that should all be neutrons. Data selection is determined primarily by examining calibration data and vetoed events. Resulting efficiencies should be accurate to about 10%. Results of CDMS data from 1998 and 1999 with a relaxed fiducial-volume cut (resulting in 15.8 kg-days exposure on Ge) are consistent with an earlier analysis with a more restrictive fiducial-volume cut. Twenty-three WIMP candidate events are observed, but these events are consistent with a background from neutrons in all ways tested. Resulting limits on the spin-independent WIMP-nucleon elastic-scattering cross-section exclude unexplored parameter space for WIMPs with masses between 10-70 GeV c^{-2}. These limits border, but do not exclude, parameter space allowed by supersymmetry models and accelerator constraints. Results are compatible with some regions reported as allowed at 3-sigma by the annual-modulation measurement of the DAMA collaboration. However, under the assumptions of standard WIMP interactions and a standard halo, the results are incompatible with the DAMA most likely value at >99.9% CL, and are incompatible with the model-independent annual-modulation signal of DAMA at 99.99% CL in the asymptotic limit.Comment: 40 pages, 49 figures (4 in color), submitted to Phys. Rev. D; v.2:clarified conclusions, added content and references based on referee's and readers' comments; v.3: clarified introductory sections, added figure based on referee's comment

Direct Top Quark Production at Hadron Colliders as a Probe of New Physics

We examine the effect of an anomalous flavor changing chromomagnetic moment which allows direct top quark production (two partons combining into an unaccompanied single top quark in the s-channel) at hadron colliders. We consider both t-c-g and t-u-g couplings. We find that the anomalous charm quark coupling parameter $\kappa_c / \Lambda$ can be measured down to $.06 TeV^{-1}(.009 TeV^{-1}$) at the Tevatron with the Main Injector upgrade(LHC). The anomalous up quark coupling parameter $\kappa_u / \Lambda$ can be measured to $.02 TeV^{-1}(.003 TeV^{-1}$) at the Tevatron(LHC).Comment: 14 pages, Latex, requires feynm

Search for Single Top Production at LEP

Single top production in e+e- annihilations is searched for in data collected by the L3 detector at centre-of-mass energies from 189 to 209 GeV, corresponding to a total integrated luminosity of 634 pb-1. Investigating hadronic and semileptonic top decays, no evidence of single top production at LEP is obtained and upper limits on the single top cross section as a function of the centre-of-mass energy are derived. Limits on possible anomalous couplings, as well as on the scale of contact interactions responsible for single top production are determined

Block-based syntax from context-free grammars

Block-based programming systems employ a jigsaw metaphor to write programs. They are popular in the domain of programming education (e.g., Scratch), but also used as a programming interface for end-users in other disciplines, such as arts, robotics, and configuration management. In particular, block-based environments promise a convenient interface for Domain-Specific Languages (DSLs) for domain experts who might lack a traditional programming education. However, building a block-based environment for a DSL from scratch requires significant effort. This paper presents an approach to engineer block-based language interfaces by reusing existing language artifacts. We present Kogi, a tool for deriving block-based environments from context-free grammars. We identify and define the abstract structure for describing block-based environments. Kogi transforms a context-free grammar into this structure, which then generates a block-based environment based on Google Blockly. The approach is illustrated with four case studies, a DSL for state machines, Sonification Blocks (a DSL for sound synthesis), Pico (a simple programming language), and QL (a DSL for questionnaires). The results show that usable block-based environments can be derived from context-free grammars, and with an order of magnitude reduction in effort

Covered stents versus Bare-metal stents in chronic atherosclerotic Gastrointestinal Ischemia (CoBaGI): Study protocol for a randomized controlled trial

Background: Chronic mesenteric ischemia (CMI) is the result of insufficient blood supply to the gastrointestinal tract and is caused by atherosclerotic stenosis of one or more mesenteric arteries in > 90% of cases. Revascularization therapy is indicated in patients with a diagnosis of atherosclerotic CMI to relieve symptoms and to prevent acute-on-chronic mesenteric ischemia, which is associated with high morbidity and mortality. Endovascular therapy has rapidly evolved and has replaced surgery as the first choice of treatment in CMI. Bare-metal stents (BMS) are standard care currently, although retrospective studies suggested significantly highe

Rail commuter service quality in South Africa: results from a longitudinal study

Rail transport is a critical mass transit mode in South Africa performing in excess of 400 million passenger trips per annum. Within a high density metropolitan region it is expected that rail passenger transport form the backbone of the public transport system, however in the Gauteng region it is estimated that only 8% of public transport commuting trips are completed by train; approximately 2% of total commuting trip. Total rail passenger trips have declined by nearly 20% since 2013/14. This suggests that the passenger rail service provider, PRASA, is not providing the service levels that commuters require. If rail is to fulfil its expected role, it is crucial that service levels are improved. The 2014 Gauteng Household Travel Survey suggests that train users were generally dissatisfied with train services, citing availability, overcrowding on trains, punctuality and reliability of services, geographical coverage and frequencies of services as key limitations. To more accurately assess the extent of service dissatisfaction, this research applied an adapted SERVQUAL model to determine the gap between commuters’ perceptions of service quality and their expectations. The study utilised a longitudinal approach to determine whether customer perceptions of five dimensions of service quality, i.e. reliability, the extent of the service, comfort, safety and affordability had changed over a two-year period. The results indicate changing gaps in most of the dimensions and a number of attributes were identified as having influenced the perception of service quality significantly enough to lead to customer dissatisfaction.This research provides transport authorities and public transport operators responsible for the provision and subsidisation of public transport with a tool characterised by a good degree of openness and flexibility, to fit individual needs. It might also be of interest for practitioners wishing to explore the main drivers of satisfaction among transport users.Papers Presented at the 2018 37th Southern African Transport Conference 9-12 July 2018 Pretoria, South Africa. Theme "Towards a desired transport future: safe, sufficient and affordable"

Travel behaviour and attitudes of young people in the johannesburg metropolitan area, south africa

The travel behaviour of millennials, young adults under the age 34, have received increased attention over recent years. As millennials represent approximately 40% of the South African population, the push factors that motivate their travel behaviour is important for transport service providers and planners. This article investigates the travel behaviour of millennials in the Johannesburg metropolitan area by identifying their preferred mode choice for different trip purposes, their service quality perceptions of different transport modes, their views on how to encourage the use of public transport and their private car ownership intentions. This research utilises a quantitative research design and empirical data were collected from a convenience sample of 630 millennials in the Johannesburg area. The research instrument was a self-administered online survey. The results indicate that young people tend to use public transport options for work and educational trips and are more inclined to make use of private car and ride-hailing services (Uber/Bolt)) for leisure and after-hours trips. Most millennials indicate that they intend to procure a private car as soon as they can afford it. These intentions are essentially determined by their opinion that the quality of public transport is inadequate and unsafe.Papers presented virtually at the 39th International Southern African Transport Conference on 05 -07 July 202