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1 – 4 of 4Nikolai Kashaev, Stefan Riekehr, Kay Erdmann, Alexandre Amorim Carvalho, Maxim Nurgaliev, Nikolaos Alexopoulos and Alexandra Karanika
Composite materials and metallic structures already compete for the next generation of single-aisle aircraft. Despite the good mechanical properties of composite materials…
Abstract
Purpose
Composite materials and metallic structures already compete for the next generation of single-aisle aircraft. Despite the good mechanical properties of composite materials metallic structures offer challenging properties and high cost effectiveness via the automation in manufacturing, especially when metallic structures will be welded. In this domain, metallic aircraft structures will require weight savings of approximately 20 per cent to increase the efficiency and reduce the CO2 emission by the same amount. Laser beam welding of high-strength Al-Li alloy AA2198 represents a promising method of providing a breakthrough response to the challenges of lightweight design in aircraft applications. The key factor for the application of laser-welded AA2198 structures is the availability of reliable data for the assessment of their damage tolerance behaviour. The paper aims to discuss these issues.
Design/methodology/approach
In the presented research, the mechanical properties concerning the quasi-static tensile and fracture toughness (R-curve) of laser beam-welded AA2198 butt joints are investigated. In the next step, a systematic analysis to clarify the deformation and fracture behaviour of the laser beam-welded AA2198 four-stringer panels is conducted.
Findings
AA2198 offers better resistance against fracture than the well-known AA2024 alloy. It is possible to weld AA2198 with good results, and the welds also exhibit a higher fracture resistance than AA2024 base material (BM). Welded AA2198 four-stringer panels exhibit a residual strength behaviour superior to that of the flat BM panel.
Originality/value
The present study is undertaken on the third-generation airframe-quality Al-Li alloy AA2198 with the main emphasis to investigate the mechanical fracture behaviour of AA2198 BMs, laser beam-welded joints and laser beam-welded integral structures. Studies investigating the damage tolerance of welded integral structures of Al-Li alloys are scarce.
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Konstantinos Fassoulis and Nikolaos Alexopoulos
The purpose of this study is to examine degree of job satisfaction of the University of Athen’s (UOA) administrative staff, specifically regarding the workplace and its impact on…
Abstract
Purpose
The purpose of this study is to examine degree of job satisfaction of the University of Athen’s (UOA) administrative staff, specifically regarding the workplace and its impact on their productivity.
Design/methodology/approach
Questionnaires were distributed to 160 administrative personnel of the UOA. The study entails descriptive analysis, independent samples t-tests, ANOVA, Pearson correlations (two-tailed) and regression analysis of the data collected.
Findings
The results indicate that the UOA’s administrative staff is dissatisfied with most aspects of their workplace, which is characterized by an inability to encourage and support new forms of office work. This scenario was also found to have a negative effect on productivity. In addition, regression analysis showed that satisfaction with the workplace is a significant predictor of employee productivity.
Research limitations/implications
A limitation of this study is that the sample was not from the UOA administrative staff that works in more recently constructed office buildings away from the Athens city center. Further investigation would also be needed to identify possible differences in satisfaction with the workspace and its impact on productivity, based on demographic characteristics, such as the level of education and years of employment.
Practical implications
The research results may be useful to public institution administrations like that of the UOA, as it highlights changes in the workplace which can have significant impact on employee job satisfaction and productivity, and consequently, the efficiency and effectiveness of the services provided.
Originality/value
This study examines aspects of the workspace of a public organization regarding their individual attributes. Given that the existing Greek literature in this field does not contain a discussion on the impact of the workplace on job satisfaction and productivity as far as the public sector is concerned, this paper may contribute to a smoother and more efficient provision of services from its organizations/institutions.
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Stilian Stanev, Hardy Krappe, Hischam Abul Ola, Konstantinos Georgoulias, Nikolaos Papakostas, George Chryssolouris and Jivka Ovtcharova
The purpose of this article is to introduce an innovative methodology to support manufacturing changes in the foundation of flexibility measurements and evaluations and to…
Abstract
Purpose
The purpose of this article is to introduce an innovative methodology to support manufacturing changes in the foundation of flexibility measurements and evaluations and to integrate this in the companies' internal as well as companies' cross‐organisational processes of change management.
Design/methodology/approach
The approach consists of two phases: first, a consistent systematics for the production systems flexibility evaluation is presented; second, the change processes are analysed and quantified flexibility indicators are integrated to support the decision – making process.
Findings
The application of the methodology in manufacturing environments has demonstrated that consideration of flexibility in the production and its integration into the manufacturing change processes has a great potential.
Originality/value
The originality of this work is in the integrated approach to consider flexibility as support for the change management. In particular the integration of quantified flexibility measurements into the change processes comes out to be the real innovation of the project.
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Nikolaos Kaiseroglou, Eleni Sfakianaki and Christina Siontorou
The purpose of this paper is to investigate perceptions of primary education (PE) teachers with respect to evaluation within the framework of Total Quality Management (TQM) and…
Abstract
Purpose
The purpose of this paper is to investigate perceptions of primary education (PE) teachers with respect to evaluation within the framework of Total Quality Management (TQM) and their readiness to engage in the process of quality improvement. Within this context, a relevant measurement instrument is developed and empirically validated.
Design/methodology/approach
The instrument developed herein included 30 items distributed across seven dimensions. It was disseminated among public PE units in Greece, yielding a substantial 2,088 responses. Several tests were performed, including principal component analysis, confirmatory factor analysis and structural equation modelling.
Findings
The findings supported the validity and reliability of the instrument, confirming that the proposed measures encapsulate actual dimensions that are most suitable for exploring evaluation perception and readiness in the context of TQM in PE. The study explored several correlations between the validated dimensions and independent variables such as gender, level of education, years of teaching experience and age. These analyses yielded additional valuable insights, enriching the depth of understanding provided by the present research.
Practical implications
The fields of TQM and PE lack empirical evidence. However, this study offers valuable insights into teachers’ perceptions of evaluation and broader quality improvement efforts. This can help school managers, policymakers and practitioners refine their implementation strategies for educational excellence.
Originality/value
To the best of the authors’ knowledge, this study is the first to focus on the examination of evaluation as a key aspect of TQM within the context of PE. Through the development and validation of a real-time measurement instrument, it bridges a significant research gap, providing practitioners and researchers with a vital tool to understand and improve educators’ evaluation perceptions, enabling targeted interventions for enhanced performance.
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