Radomir Zekavica, Biljana Simeunovic-Patic, Phillippus J. Potgieter and Cornelis J. Roelofse
The purpose of this paper is to present the results of the first research on prevalence, nature and correlates of the police cynicism in Serbia, with particular attention to the…
Abstract
Purpose
The purpose of this paper is to present the results of the first research on prevalence, nature and correlates of the police cynicism in Serbia, with particular attention to the associations of cynicism with job satisfaction.
Design/methodology/approach
Data were collected using a paper-based survey, and obtained from 472 police officers from five police departments across the country. For the purpose of measuring of organizational and work aspects of police cynicism a new developed 24 five-level Likert-type items scale was used.
Findings
The results show that cynicism is normally distributed. No statistically significant gender, education or police rank differences were identified, and the length of service does not appear to influence cynical attitudes significantly. Cynicism scores statistically significantly varied across police departments and predicted job dissatisfaction. The underlying four-factor structure of police cynicism was identified. The factors include: general organizational cynicism; cynicism toward police hierarchy/superiors; cynicism toward public/citizen cooperation; and cynicism toward modernization of policing in the crime control field.
Research limitations/implications
The generalizability of the sample is limited, giving that participants come from only five out of a total of 27 police departments in the country, while the female police officers and officers with education higher than high school were somewhat overrepresented.
Originality/value
This research provides some more evidence on the nature and determinants of police cynicism that might inspire future research in this important but under-researched area. It implies that the need to explore more deeply relations between police cynicism and stress, burnout and particularly contextual and departmental factors that might be influential to police cynicism. It might also incite future research on the internal structure of police cynicism.
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F.V. Adams, P.A. Olubambi, J.H. Potgieter and J. Van Der Merwe
The purpose of this paper is to supplement the scant previous investigations on the corrosion behaviour of 2205 and 2507 duplex stainless steels in selected organic acids…
Abstract
Purpose
The purpose of this paper is to supplement the scant previous investigations on the corrosion behaviour of 2205 and 2507 duplex stainless steels in selected organic acids containing chloride additions.
Design/methodology/approach
Microstructural examination of the alloys was first carried out, after which the corrosion behaviour of the alloys in citric, oxalic, formic and acetic acids containing chloride additions at varying temperatures was studied using electrochemical techniques.
Findings
The alloy 2507 material had a larger grain size than did the alloy 2205 sample. The corrosion resistances of the alloys generally are highest in acetic acids and lowest in citric acid. The addition of chloride had a pronounced effect on their corrosion resistance. Alloy 2507 generally exhibited higher corrosion resistance in all of the acids than alloy 2205, with the exception of acetic acid at room temperature. The 50:50 ratio of ferrite to austenite composition, as revealed by phase compositional analysis, indicated no significant possibility for galvanic corrosion between the phases. This suggests that the corrosion behaviour of the alloys is controlled by their grain sizes and chemical compositions.
Originality/value
Although the corrosion behaviour of duplex stainless steels in some organic acid media has been reported, this investigation covers the major organic acids not previously reported. Since in real industrial systems a mixture of both organic and minerals acids/salts may typically exist, investigations of the combined effect of chloride ions with the organic acids reported in this paper typify real industrial operations. The paper thus provides a basis for material selection for the application of 2205 and 2507 in industrial systems where organic acids are mostly used.
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A. van Bennekom and J.H. Potgieter
The failure of a conditioning tower at a cement plant was investigated. It was found that the structure failed due to a combination of high temperature oxidation and sulphidation…
Abstract
The failure of a conditioning tower at a cement plant was investigated. It was found that the structure failed due to a combination of high temperature oxidation and sulphidation. This was aggravated by the presence of sodium and potassium salts in the exit gases. It was concluded that a stainless steel with a higher chromium content than the 3CR12 would be more suitable for this application.
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N.S. Tlale, J. Potgieter and G. Bright
The skill of the camera operator in controlling the orientation of camera platforms in the film industry is one of the crucial factors in producing movies with good…
Abstract
The skill of the camera operator in controlling the orientation of camera platforms in the film industry is one of the crucial factors in producing movies with good cinematography. Some film footage requires landscapes that make it difficult for the camera operator to efficiently operate the camera platform. Tether connections limit the manner in which the camera platform can be mounted in order to achieve the best scene shooting. This paper reports on the project undertaken by the Mechatronics and Robotics Research Group at Massey University, in conjunction with the New Zealand film industry, on the development of wireless control camera platforms.
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Kasturie Premlall, J. Herman Potgieter and S. Potgieter‐Vermaak
The effect of chlorides on corrosion of reinforcing steel is well documented in the literature. However, few studies have focused attention on the effect of sulphates on the…
Abstract
Purpose
The effect of chlorides on corrosion of reinforcing steel is well documented in the literature. However, few studies have focused attention on the effect of sulphates on the corrosion of low carbon steel in alkaline media. This paper aims to address this issue.
Design/methodology/approach
This paper describes the results of the investigation into the corrosion behaviour of low carbon steel (typically used as reinforcing steel), exposed to alkaline media at a pH of 9 and 12 with varying concentrations of sulphate and chloride ions, as well as, in sulphate only solutions. An attempt was made to inhibit corrosion of steel exposed to the corrosive media using laser surface treatment of the steel specimens. Mass loss tests and electrochemical tests were conducted to evaluate the effect of sulphate only and the combined effect of sulphate and chloride ions in an alkaline media on steel.
Findings
It was found that sulphate ions could cause corrosion of steel in alkaline media. The severity of the attack increased with increasing sulphate ion concentrations, as well as with combinations of sulphate and chloride ions. The pH 12 conditions seem to show much more critical attack with evidence of pitting corrosion as compared to uniform corrosion for test conditions at a pH of 9. The attempt to inhibit the observed corrosion of steel exposed to the corrosive high alkaline media containing sulphate ions on their own and in combination of chloride ions by laser surface treatment proved to be successful.
Originality/value
The research undertaken here adds to the body of knowledge relating to the effect of sulphate ions on reinforcing steel corrosion in highly alkaline media. Most literature points out that sulphate ions on their own do not have a corrosive effect, but rather, a passivating effect!
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Despite the South African legislature’s intention to introduce capital gains tax (CGT) as a simple and clear tax, it is an extremely complex tax. Several provisions of both the…
Abstract
Despite the South African legislature’s intention to introduce capital gains tax (CGT) as a simple and clear tax, it is an extremely complex tax. Several provisions of both the Eighth Schedule to the Income Tax Act 58 of 1962 and the Act itself have to be taken into account in determining whether a taxable capital gain or an assessed capital loss has arisen during the year of assessment. The application of these principles is often surrounded by uncertainty. Hence, the purpose of this article is not only to provide an overview of some of the different provisions that have to be taken into account and the interaction between them, but also to highlight some of the problems arising from the application of the principles themselves.
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The drama of Angola's recent history must be seen against the backdrop of political developments in Southern Africa, which had a direct impact on the turn of events in the civil…
Abstract
The drama of Angola's recent history must be seen against the backdrop of political developments in Southern Africa, which had a direct impact on the turn of events in the civil war. During the 1960s and 1970s, the conflict was widely regarded as a prominent example of a liberation struggle against the Portuguese colonial regime. In contrast, the bitter battle in the 1980s and early 1990s between UNITA and the Movimento Popular de Libertação de Angola (Popular Movement for the Liberation of Angola – MPLA), the party which has dominated the government in Luanda since independence, was seen as a proxy war between the superpowers over the control of a key African state. During the final phase of the conflict, from the mid-1990s to early 2002, Angola was viewed as a quintessential resource conflict, a power play over access to valuable commodities such as diamonds and crude oil (Global Witness, 1998; Global Witness, 1999). All these categorizations – which reflect the dominant themes in conflict analyses of their time – fall somewhat short of grasping the complex reality of the Angolan conflict. Nevertheless, the shifting position of much of the industrialized world – particularly of the United States at the end of the Cold War – goes a long way toward explaining how the FAA managed, during the mid-1990s, to turn a decade-long military stalemate on the battlefield into a decisive victory. Looking at the geo-strategic picture also helps to explain why it took the comprehensive sanctions regime against UNITA so long to become effective in cutting the supply lines for arms, ammunition, and fuel.
Jacob Mhlanga, Theodore C. Haupt and Claudia Loggia
This paper aims to explore the intellectual structure shaping the circular economy (CE) discourse within the built environment in Africa.
Abstract
Purpose
This paper aims to explore the intellectual structure shaping the circular economy (CE) discourse within the built environment in Africa.
Design/methodology/approach
The study adopted a bibliometric analysis approach to explore the intellectual structure of CE in the built environment in Africa. The authors collected 31 papers published between 2005 and 2021 from the Scopus database and used VOSviewer for data analysis.
Findings
The findings show that there are six clusters shaping the intellectual structure: demolition, material recovery and reuse; waste as a resource; cellulose and agro-based materials; resilience and low-carbon footprint; recycling materials; and the fourth industrial revolution. The two most cited scholars had three publications each, while the top journal was Resources, Conservation and Recycling. The dominant concepts included CE, sustainability, alternative materials, waste management, lifecycle, demolition and climate change. The study concludes that there is low CE research output in Africa, which implies that the concept is either novel or facing resistance.
Research limitations/implications
The data were drawn from one database, Scopus; hence, adoption of alternative databases such as Web of Science, Google Scholar and Dimensions could potentially have yielded a higher number of articles for analysis which potentially would result in different conclusions on the subject understudy.
Originality/value
This study made a significant contribution by articulating the CE intellectual structure in the built environment, identified prominent scholars and academic platforms responsible for promoting circularity in Africa.
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Guifei Wang, Ming Cong, Weiliang Xu, Haiying Wen and Jing Du
This paper aims to describe how a novel biomimetic chewing robot was designed, including its motion, force, control and mechanical designs, and shows some initial experiments…
Abstract
Purpose
This paper aims to describe how a novel biomimetic chewing robot was designed, including its motion, force, control and mechanical designs, and shows some initial experiments about motion tracking.
Design/methodology/approach
According to the biomechanics, the authors modeled the muscles of mastication in six linkages and the temporomandibular joint in higher kinematic pairs of point contact. As a result, the chewing robot was represented in a redundantly actuated parallel mechanism. With reference to literature data on the biological system, the authors specified the motion and force requirements for the robot via inverse kinematics and force analysis. A prototype of the robot was built, which has a position control system and is driven by six linear actuators. Experiments were conducted to show the capability of the robot in reproducing the human chewing motion.
Findings
A chewing robot was successfully modeled and developed, which is able to simulate the motion of human mastication in a biologically faithful way.
Practical implications
The chewing robot as a scientific instrument can be used to test dental materials and evaluate food textural properties of chewing.
Originality/value
Two higher kinematic pairs of point contact are proposed to simulate the two temporomandibular joints. The mechanism of the novel chewing robot is the first of this kind, which has two higher kinematic pairs of point contact and is a redundantly actuated spatial parallel mechanism.
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Siavash Moayedi, Jamal Zamani and Mohammad Salehi
This paper aims to provide a full introduction, new classification, comparison and investigation of the challenges as well as applications of layerless 3D printing, which is one…
Abstract
Purpose
This paper aims to provide a full introduction, new classification, comparison and investigation of the challenges as well as applications of layerless 3D printing, which is one of the industry 4.0 pioneers.
Design/methodology/approach
Given the significance and novelty of uniform 3D printing, more than 250 publications were collected and reviewed in an unbiased and clear manner.
Findings
As a result, the majority of uniform parts printed in polymer form are known up to this point. In a novel division for better researchers’ comprehension, uniform printing systems were classified into three categories: oxygen inhibition (OI), liquid lubrication (LL) and photon penetration (PP), and each was thoroughly investigated. Furthermore, these three approaches were evaluated in terms of printing speed, precision and accuracy, manufacturing scale and cost.
Originality/value
The parameters of each approach were compared independently, and then a practical comparison was conducted among these three approaches. Finally, a variety of technologies, opportunities, challenges and advantages of each significant method, as well as a future outlook for layerless rapid prototyping, are presented.