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Computation have been made of the three‐dimensional flow field development, chemical reaction and combustion processes in a typical afterburner system under both isothermal and reacting flow conditions. The calculations are based upon a numerical solution of the time‐averaged transport equations for mass, momentum, turbulence kinetic energy, dissipation rate, enthalpy and species concentrations using a finite‐volume formulation. The physical models include the k—ε turbulence model, the eddy break‐up model, a two‐step reaction model, a droplet vaporization and combustion model and six‐flux radiation model. The mean flow structures are presented in important longitudinal and cross‐sectional planes which show certain striking similarities and contrasting differences for isothermal and reacting flows. The flame stabilizer flow is shown to be dominated by a complex combination of recirculation and vortex patterns. Combustion alters convergence and mixing flow patterns downstream of the flame stabilizer, thus influencing the selection of the fuel injection system. The predicted reacting flow parameters identify a number of design parameters such as fuel injector location, high degree reaction zone, nozzle opening area and the corresponding fuel flow rate.

Aluminium and its alloys are the most preferred material in aerospace and automotive industries because of their high strength-to-weight ratio. However, these alloys are found to be low wear resistance. Hence, the incorporation of ceramic particles with the aluminium alloy may be enhanced the mechanical and tribological properties. The purpose of this study is to optimize the specific wear rate and friction coefficient of titanium dioxide (TiO₂) reinforced AA7075 matrix composites. The four wear control factors are considered, i.e. reinforcement (Wt.%), applied load (N), sliding velocity (m/s) and sliding distance (m).

The composites were fabricated through stir casting route with varying weight percentages (0, 5, 10 and 15 Wt.%) of TiO₂ particulates. The mechanical properties of the composites were studied. The specific wear rate and friction coefficient of the newly prepared composites was determined by using a pin-on-disc apparatus under dry sliding conditions. Experiments were planned as per Taguchi’s L16 orthogonal design. Signal-to-noise ratio analysis was used to find the optimal combination of parameters.

The mechanical properties such as yield strength, tensile strength and hardness of the composites significantly improved with the addition of TiO₂ particles. The analysis of variance result shows that the applied load and reinforcement Wt.% are the most influencing parameters on specific wear rate and friction coefficient during dry sliding conditions. The scanning electron microscope morphology of the worn surface shows that TiO₂ particles protect the matrix from more removal of material at all conditions.

This paper provides a solution for optimal parameters on specific wear rate and friction coefficient of aluminium matrix composites (AMCs) using Taguchi methodology. The obtained results are useful in improving the wear resistance of the AA7075-TiO₂ composites.

Aluminum alloy AA5083 is applicable in ship building, military, railway and industry because of its excellent properties like resistance to chemical and sea water attack. However, its performance is affected by weak wear resistance. Hence, this should be solved to improve the performance of AA5083 alloy in the aforementioned fields. The purpose of this research is to enhance the wear properties of AA5083 alloy.

In this research, AA5083 alloy was reinforced with industrial wastes such as red mud and granite particles using stir casting method. Totally, four types of composites were fabricated, namely, AA5083/3 Wt.% red mud (C1), AA5083/3 Wt.% granite (C2), AA5083/1 Wt.% red mud-2Wt.% granite (C3) and AA5083/2 Wt.% red mud-1Wt.% granite (C4). Wear properties such as mass loss and coefficient of friction (COF) were analyzed for different wear parameters. Further, the mechanical properties like hardness and tensile strength were investigated.

Results showed that the inclusion of reinforcement particles improved the wear and mechanical properties of AA5083 alloy (C0). The C2 sample displayed the maximum hardness of 87 HV and tensile strength of 317 MPa owing to the inclusion of 3 Wt.% granite particles. Furthermore, the wear study results showed that the C2 sample displayed the minimum mass loss and COF. It was concluded from this research that C2 sample could be a good candidate to be applicable in marine, military, railway and industrial applications with improved performance.

This work is original as the industrial waste is used as reinforcements in the performance improvement of AA5083 aluminum alloy.

Because of the significant differences in the features and requirements of specific products and the capabilities of various additive manufacturing (AM) solutions, selecting the most appropriate AM technology can be challenging. This study aims to propose a method to solve the complex process selection in 3D printing applications, especially by creating a new multicriteria decision-making tool that takes the direct certainty of each comparison to reflect the decision-maker’s desire effectively.

The methodology proposed includes five steps: defining the AM technology selection decision criteria and constraints, extracting available AM parameters from the database, evaluating the selected AM technology parameters based on the proposed decision-making methodology, improving the accuracy of the decision by adopting newly proposed weighting scheme and selecting optimal AM technologies by integrating information gathered from the whole decision-making process.

To demonstrate the feasibility and reliability of the proposed methodology, this case study describes a detailed industrial application in rapid investment casting that applies the weightings to a tailored AM technologies and materials database to determine the most suitable AM process. The results showed that the proposed methodology could solve complicated AM process selection problems at both the design and manufacturing stages.

This research proposes a unique multicriteria decision-making solution, which employs an exclusive weightings calculation algorithm that converts the decision-maker's subjective priority of the involved criteria into comparable values. The proposed framework can reduce decision-maker's comparison duty and potentially reduce errors in the pairwise comparisons used in other decision-making methodologies.

The purpose of this paper is to examine whether the seasonal anomaly known as the reverse weekend effect detected at index level can also be observed at individual stock level.

This paper's methodology is based on the model first developed by Connolly and then employed by Chang, Pinegar, and Ravichandran in which returns are regressed against the dummy variable for Monday. In addition, the conditional variance is also included into the mean equation following Engle, Lilien, and Robins. Given the increasing evidence that equity returns are conditionally heteroskedastic, the paper includes in the conditional variance the lag of the squared residual from the mean equation (i.e. autoregressive conditional heteroskedasticity term introduced by Engle) and the previous period's forecast variance (i.e. the generalized autoregressive conditional heteroskedasticity term introduced by Bollerslev). Also, the paper controls for the different impact of good and bad news on the conditional variance following Glosten, Jaganathan, and Runkle.

It is found that the anomaly is widely distributed among large firms, not just confined to a few firms. The finding suggests that the anomaly at the index level is not driven by the extreme returns of a few firms. The paper also finds that the anomaly at the firm level is not evenly distributed across the weeks of the month. Furthermore, trading volume and illiquidity of individual firms can only partially explain the seasonal anomaly.

This paper extends the study of the reverse weekend effect in individual firms.

All humans have an innate ability to learn multiple languages and with ­increasing mobility across linguistic boundaries, people are more than ever embracing multilingualism. This chapter examines international students’ perceptions of their third language (L3) learning experience in their second language (L2) English context. Challenges and strategies of L3 learning are explored as data from a survey and interviews were analyzed. Twenty-eight (n = 28) international students were asked to answer Likert-scale and ­open-­ended questions regarding their L3 learning experience. Select ­participants were also interviewed. The quantitative and qualitative results show that learning an L3 not only offered international students an opportunity to strengthen their understanding of the relationship between language and culture, but also allowed them to position themselves as multilinguals within the globalized world context. Furthermore, the data reveal that technology is an integral part of international students’ L3 learning process, but that additional support is needed. This chapter also discusses ideas including technology-e­nhanced language learning to assist international students in their L3 learning experience in higher education.

Aerospace and defence industries use the materials having better properties at elevated temperatures, and Inconel 718 is one of that. The complexity in realizing complex and intricate shapes necessitate the product realization through additive manufacturing. This paper aims to investigate the wear behaviour of additive manufactured material.

The wear behaviour of additively manufactured Inconel 718 samples through direct metal laser sintering process at three different build orientations was experimentally investigated using a standard pin-on-disc wear tester.

Among the varied wear parameters, the load was identified as the most influencing parameter on the wear rate. In addition, the post-failure analysis of the worn surface of the pins under the scanning electron microscopy revealed the presence of various wear mechanisms.

Almost, the industries are now focussed on their production through additive manufacturing owing to its advantages. The present work displays the wear behaviour of the additive manufactured Inconel 718 and its associated wear mechanisms.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2019-0322.

In a recent study, Liano, Liano and Manakyan (1999) conclude that the pattern of day‐of‐the‐week effects in stock indices differs between Democratic administrations and Republican administrations. Specifically, the weekend effect is more pronounced during Republican administrations. This paper re‐examines this issue. It incorporates into the analysis the implications of Connolly's (1989) findings that the weekend effect has disappeared since 1975. We confirm Connolly's results. However, contrary to Liano et al. (1999), we conclude that day‐of‐the‐week effects are not significantly moderated by the political administration.

Recent research has focused on the influence of the political party of the US President on stock indices. This current paper extends this area of research by including the influence of the political party that holds the majority in Congress into the research design. The results do not support the hypothesis that there is a statistically significant relationship between the political party of the president and the return on the stock index. However, the political party with the majority in Congress is significantly related to the return on the index. The returns during Republican controlled Congresses are higher than returns during Democrat controlled Congresses.

Information systems (IS) project failure has been a recurring problem for decades. The purpose of this paper is twofold: first, to examine the key factors that influence project failure and an analysis of the major areas that can have a significant impact on success; and second, to explore some of the key aspects that have an impact on project management performance from the practitioner perspective and discusses the problems faced by organizations in the closer integration of change and project management.

This study critically reviews the IS failure literature developing a synthesized view of the key issues and common reasons for projects to fail. The approach taken in this study is one that focuses on a number of key questions that pull together the relevant themes in this genre of research whilst highlighting many of the implications for practitioners and organizations alike.

Key questions remain on the underlying causes of instances of poor project management as an IS failure factor. The literature has omitted to develop a deeper analysis of the associations between failure factors and the potential causal relationships between these factors. The realization of project benefits relies on the success of both change and project management yet the formal integration of these two disciplines is constrained by separate standards bodies and an immature body of research.

This study is limited by its theoretical nature lacking an empirical element to provide a deeper analysis of IS failure factors and their interrelationships. This specific area is a recommendation for future research, where causal relationships between failure factors could be developed via a mathematic-based method such as interpretive structural modeling.

With failure rates of IS projects still unacceptably high after decades of attempts to significantly change outcomes, a deeper analysis of this topic is required. The research gaps and recommendations for practitioners highlighted in this study have the potential to provide valuable contributions to this topic of research.

The intent of this study is to present a new perspective of this genre of IS research that develops the main arguments and gaps in the literature from the practitioner viewpoint.