Rapid die manufacturing using direct laser metal deposition

Published ArticleGlobal issues such as energy and climate changes have impacted on both the automotive and aerospace industries, forcing them to adopt measures to produce products that consume fewer combustibles and emit less carbon dioxide. Making vehicles lighter is one of the logical ways of reducing fuel consumption. The need for light components, able to fulfil technical and quality specifications, led to market growth for tooling that is able to mass produce parts using manufacturing processes such as high pressure die casting. Competitive pressures to reduce the lead time required for tooling-up has also increased dramatically. For this reason research into various methods, techniques and approaches to tool manufacture is being undertaken globally. This paper highlights the work undertaken at the CSIR on the issue of rapid die manufacturing through the application and evaluation of a rapid prototyping technique and coating technologies applied to die components of a high pressure casting die for the production of aluminium components. Criteria for determining suitability were developed against which the technique was evaluated that included time, cost and life-expectancy. Results of accelerated testing procedures to evaluate the die material produced by the rapid prototyping technique and surface coatings and treatments of die materials for their resistance to washout, erosion, heat checking and corrosion in a high pressure die casting environment, are presented. The outcomes of this research will be used for further development and application of specific techniques, design principles and criteria for this approach

Ultrasound comparison of the effects of prehabilitation exercises and the scapular assistance test on the acromiohumeral distance

Abstract: Background: Prolonged participation in overhead sports creates shoulder muscle imbalances which eventually alter the efficacy of the shoulder stabiliser muscles and heighten injury risk, such as subacromial impingement syndrome. Objectives: The aim of this study was to determine if ultrasound is effective to measure the acromiohumeral distance (AHD) to compare the effect of the scapular assistance test (SAT) on the AHD with a prehabilitative exercise intervention programme in asymptomatic cricket players. Methods: Baseline testing on cricket players from the North- West University cricket squad (N=34) included AHD measurements performed by a sonographer at 0°, 30° and 60° humeral abduction angles respectively, with and without the SAT application. Players were then randomly assigned to an intervention and control group..

Ultrasound comparison of the effects of prehabilitation exercises and the scapular assistance test on the acromiohumeral distance

Abstract: Background: Prolonged participation in overhead sports creates shoulder muscle imbalances which eventually alter the efficacy of the shoulder stabiliser muscles and heighten injury risk, such as subacromial impingement syndrome. Objectives: The aim of this study was to determine if ultrasound is effective to measure the acromiohumeral distance (AHD) to compare the effect of the scapular assistance test (SAT) on the AHD with a prehabilitative exercise intervention programme in asymptomatic cricket players. Methods: Baseline testing on cricket players from the North- West University cricket squad (N=34) included AHD measurements performed by a sonographer at 0°, 30° and 60° humeral abduction angles respectively, with and without the SAT application. Players were then randomly assigned to an intervention and control group..

How standard (and valid) are South African parking standards?

Papers presented virtually at the 41st International Southern African Transport Conference on 10-13 July 2032Parking standards ensure that the correct parking allocation is provided for at land uses. Historically, minimum parking standards were applied worldwide, indicating the minimum number of parking bays that must be provided per land use. Many industrialised countries now regulate parking allowances by applying a maximum parking rate, limiting the number of parking bays per land use, which can assist to reduce travel demand and promote sustainable transport options. South Africa still adheres to minimum parking standards. Parking standards in South Africa are curated and published by individual local and metropolitan municipalities. The first objective of this paper is to compare South African parking standards in various municipalities for numerous land uses. Parking standards were observed to vary widely between municipal areas, resulting in vastly different parking requirements for the same land uses. The second objective of this research was to develop a methodology to conduct representative parking studies to evaluate if there is regularly an oversupply in parking bays at new developments as a result of minimum parking requirements. The findings of this paper indicate that South African parking standards should be reviewed to allow an equitable approach to parking provision between municipalities. Research into a move to maximum parking standards is also required to prevent an oversupply of parking and encourage sustainable transport usage where public transport options are available

Vehicle acceleration estimation using smartphone-based sensors

Recent advances in smartphone technology, including motion sensing and wireless communications, have resulted in these devices being used for vehicle-based driver behaviour sensing applications, replacing existing bespoke vehicle-based solutions. Acceleration is normally used as the primary indicator for recklessness. Despite the many benefits of using a smartphone to determine vehicle acceleration, the mobility of the phone relative to the vehicle, and the vehicle relative to the earth, causes the earth's gravitational force to obscure the true vehicle acceleration as perceived by the phone. The design and test results in this paper demonstrate how quaternions and an unscented Kalman filter can be used to remove the gravitational vector from the sensed acceleration, which enables reckless driving detection.Paper presented at the 34th Annual Southern African Transport Conference 6-9 July 2015 "Working Together to Deliver - Sakha Sonke", CSIR International Convention Centre, Pretoria, South Africa.The Minister of Transport, South AfricaTransportation Research Board of the US

Implementation of uavs and fcd in adapting to the ‘new normal’ in the transportation industry: a traffic management case study

The Transportation industry has grown over the last few decades with the improvement of current transport technologies as well as through the implementation of innovative transport practices. This growth is happening worldwide at a country-specific pace. Now, with travel restrictions due to the COVID-19 pandemic disrupting the transport sector, the Transportation industry is forced to adapt to changes in conventional travel behaviour and practices. Whether it be changes to current aspects of a transport system or reimagining entire processes, adaptation is required. This paper assesses both of these possibilities through a case study relating to traffic management processes in the study area of Stellenbosch. Changes to current traffic management processes relating to road traffic management and incident response with the use of Unmanned Aerial Vehicles (UAVs) and Floating Car Data (FCD) are assessed in this paper. Furthermore, a reimagination of the entire traffic management process is explored theoretically, which incorporates innovative transport technologies and systems. The goal of this paper is to development a framework for efficient transportation management that is relevant for a country with a developing transport infrastructure.Papers presented at the 40th International Southern African Transport Conference on 04 -08 July 202

Post-covid shifts in bus passenger trip timing and vehicle utilisation in Cape Town

Papers presented virtually at the 41st International Southern African Transport Conference on 10-13 July 2076Golden Arrow Bus Services’ ridership in Cape Town has now recovered to pre-pandemic levels, but a shift in trip timing behaviour has been observed. The purpose of this paper is to explore the nature and extent of this shift, and to consider its impacts on fleet deployment efficiency. Passenger boarding data, from a sample of weekdays before and after COVID-19 movement restrictions, are analysed. Data on peak and off-peak fleet deployment, and on the cost of a bus in service per weekday, are used to develop a rudimentary cost allocation model. It is found that the portion of weekday passenger boardings occurring in peak periods declined by 10.5% after lockdown (and by 5.8% in the peak hour), resulting in a reduction of the peak-to-base ratio from 13:1 to 10:1. It is estimated that fixed costs heavily outweigh variable costs during periods of low demand (fixed costs account for 89% of the cost of system-wide service provision in the midday off-peak hour). Because the peak scales fixed costs, a small reduction in the peak-to-base ratio is found to register a discernible cost efficiency improvement in vehicle fleet utilisation. The number of buses required to service peak demand reduced from 1 124 to 1 040 (a 7% decrease), and the number of buses servicing the off-peak expanded from 200 to 245 (a 22% increase). It is estimated that a 1% decrease in the peak-to-base ratio led to a 0.2% decrease in the daily system-wide service provision cost

A survey of participants in two internet support groups for people with hair-pulling

BACKGROUND: A substantial number of patients suffering from psychological problems or psychiatric disorders have turned to internet support groups for help. This paper reports on the perceived effectiveness of trichotillomania (TTM) internet support groups for people suffering from hair-pulling. METHODS: A questionnaire was sent via e-mail to all subscribers of two mailing lists devoted to TTM, each of which takes a somewhat different approach to the condition. The questionnaire addressed the possible benefits and problems associated with belonging to a TTM virtual support group. RESULTS: Subscribers had similar demographic features as clinical samples of trichotillomania patients. Subscribers to both internet lists found them helpful in terms of feeling supported and in obtaining information. The different approaches to TTM on the two lists were associated with differences in treatments attempted by participants. CONCLUSION: Internet support groups can potentially contribute to increasing awareness about and knowledge of psychiatric disorders such as TTM, as well as to their management. Nevertheless, additional effort is required to ensure that subscribers are able to make informed, evidence-based decisions