Marco Anilli, Ali Gökhan Demir and Barbara Previtali
The purpose of this paper is to demonstrate the use of selective laser melting for producing single and double chamber laser cutting nozzles. The main aim is to assess a whole…
Abstract
Purpose
The purpose of this paper is to demonstrate the use of selective laser melting for producing single and double chamber laser cutting nozzles. The main aim is to assess a whole production chain composed of an additive manufacturing (AM) and consecutive finishing processes together. Beyond the metrological and flow-related characterization of the produced nozzles, functional analysis on the use of the produced nozzles are carried out through laser cutting experiments.
Design/methodology/approach
SLM experiments were carried out to determine the correct compensation factor to achieve a desired nozzle diameter on steel with known processibility by SLM and using standard nozzle geometries for comparative purposes. The produced nozzles are finished through electrochemical machining (ECM) and abrasive flow machining (AFM). The performance of nozzles produced via additive manufacturing (AM) are compared to conventional ones on an industrial laser cutting system through cutting experiments with a 6 kW fibre laser. The produced nozzles are characterized in terms of pressure drop and flow dynamics through Schlieren imaging.
Findings
The manufacturing chain was regulated to achieve 1 mm diameter nozzles after consecutive post processing. The average surface roughness could be lowered by approximately 80 per cent. The SLM produced single chamber nozzles would perform similarly to conventional nozzles during the laser cutting of 1 mm mild steel with nitrogen. The double chamber nozzles could provide complete cuts with oxygen on 5 mm-thick mild steel only after post-processing. Post-processing operations proved to decrease the pressure drop of the nozzles. Schlieren images showed jet constriction at the nozzle outlet on the as-built nozzles.
Originality/value
In this work, the use of an additive manufacturing process is assessed together with suitable finishing and functional analysis of the related application to provide a complete production and evaluation chain. The results show how the finishing processes should be allocated in an AM-based production chain in a broader vision. In particular, the results confirm the functionality for designing more complex nozzle geometries for laser cutting, exploiting the flexibility of SLM process.
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Marco Montani, Ali Gökhan Demir, Ehsan Mostaed, Maurizio Vedani and Barbara Previtali
This paper aims to investigate the processability by selective laser melting (SLM) of materials of potential interest for innovative biodegradable implants, pure Fe and pure Zn…
Abstract
Purpose
This paper aims to investigate the processability by selective laser melting (SLM) of materials of potential interest for innovative biodegradable implants, pure Fe and pure Zn. The processability of these materials is evaluated with a more established counterpart in permanent implants, stainless steel. In particular, the processing conditions were studied to reduce porosity due to incomplete fusion of the powder.
Design/methodology/approach
In the first phase of the experiments, SLM of AISI 316L was studied through design of experiments method. The study was used to identify the significant parameters in the experimental range and estimate the fluence ranges for pure Fe and pure Zn using the lumped heat capacity model. In the second phase, SLM of pure Fe and pure Zn were studied using estimated fluence ranges. In the final phase, best conditions were characterized for mechanical properties.
Findings
The results showed that complete melting of AISI 316L and pure Fe could be readily achieved, whereas laser melting generated a foam-like porous structure in Zn samples. The mechanical properties of laser melt implant materials were compared to as-cast and rolled counterparts. Laser melted AISI 316L showed superior mechanical performance compared to as-cast and rolled material, whereas Fe showed mechanical performance similar to rolled mild steel. Despite 12 per cent apparent porosity, laser melted Zn exhibited superior mechanical properties compared to as-cast and wrought material because of reduced grain size.
Originality/value
The paper provides key processing knowledge on the SLM processability of new biodegradable metals, namely, pure Fe, which has been studied sparingly, and pure Zn, on which no previous work is available. The results prefigure the production of new biodegradable metallic implants with superior mechanical properties compared to their polymeric counterparts and with improved degradation rates compared to magnesium alloys, the reference material for biodegradable metals.
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Tülay Karakas, Burcu Nimet Dumlu, Mehmet Ali Sarıkaya, Dilek Yildiz Ozkan, Yüksel Demir and Gökhan İnce
The present study investigates human behavioral and emotional experiences based on human-built environment interaction with a specific interest in urban graffiti displaying fear…
Abstract
Purpose
The present study investigates human behavioral and emotional experiences based on human-built environment interaction with a specific interest in urban graffiti displaying fear and pleasure-inducing facial expressions. Regarding human behavioral and emotional experience, two questions are asked for the outcome of human responses and two hypotheses are formulated. H1 is based on the behavioral experience and posits that the urban graffiti displaying fear and pleasure-inducing facial expressions elicit specified behavioral fear and pleasure responses. H2 is based on emotional experience and states that the urban graffiti displaying fear and pleasure-inducing facial expressions elicit specified emotional fear and pleasure responses.
Design/methodology/approach
The research design is developed as a multi-method approach, applying a lab-based experimental strategy (N:39). The research equipment includes a mobile electroencephalogram (EEG) and a Virtual Reality (VR) headset. The behavioral and emotional human responses concerning the representational features of urban graffiti are assessed objectively by measuring physiological variables, EEG signals and subjectively by behavioral variables, systematic behavioral observation and self-report variables, Self-assessment Manikin (SAM) questionnaire. Additionally, correlational analyses between behavioral and emotional results are performed.
Findings
The findings of behavioral and emotional evaluations and correlational results show that specialized fear and pleasure response patterns occur due to the affective characteristics of the urban graffiti's representational features, supporting our hypotheses. As a result, the characteristics of behavioral fear and pleasure response and emotional fear and pleasure response are identified.
Originality/value
The present paper contributes to the literature on human-built environment interactions by using physiological, behavioral and self-report measurements as indicators of human behavioral and emotional experiences. Additionally, the literature on urban graffiti is expanded by studying the representational features of urban graffiti as a parameter of investigating human experience in the built environment.
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Nuri Gökhan Torlak, Ahmet Demir and Taylan Budur
The study uses VIseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR)-structural equation modeling (SEM) to construct benchmarks for service providers and evaluate a…
Abstract
Purpose
The study uses VIseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR)-structural equation modeling (SEM) to construct benchmarks for service providers and evaluate a multimethodology practice in the Internet industry.
Design/methodology/approach
The data were collected using a survey based on an email/interview with 444 Internet users participating. SEM obtained coefficient values by way of customer expectations for Internet service providers. The authors normalized coefficients and integrated them into the VIKOR method for ranking competitors in the Internet industry.
Findings
VIKOR-SEM revealed that network and information quality and security/privacy significantly positively impact customer trust while network and information quality and customer trust significantly positively affect Internet users' value perceptions. Customer services do not affect customer trust, while security/privacy and customer services have no significant influence on customer value perceptions. Though customer services and Internet users' trust and value perceptions directly, significantly and positively affect their commitments, the quality of network and information and security/privacy indirectly, significantly and positively influence customer commitments.
Research limitations/implications
The study was in the Internet industry of Iraq. The results cannot be accurate for the other countries and the service sectors. The researchers/managers can adopt the model in other service sectors to test the multimethodology.
Originality/value
VIKOR-SEM evaluated the changes in customer expectations and service providers in the Internet industry.
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Halil Zaim, Erdem Erzurum, Selim Zaim, Burhan Uluyol and Gökhan Seçgin
This study aims to propose a practical, virtue-centric model of leadership based on Islamic principles. The structure of the Islamic leadership construct is validated through…
Abstract
Purpose
This study aims to propose a practical, virtue-centric model of leadership based on Islamic principles. The structure of the Islamic leadership construct is validated through confirmatory factor analysis. Its relationship with performance and organizational commitment is examined and the mediating role of organizational commitment is assessed.
Design/methodology/approach
Islamic leadership model is tested using confirmatory factor analysis with data collected from employees working in the services sector in Turkey. Relationships between Islamic leadership, organizational commitment and performance are examined through a path analysis.
Findings
The factor analysis results presented a good fit for the proposed Islamic leadership model, which consists of wisdom, religiosity, justice and kindness dimensions. Regarding path analysis, findings indicated a positive relationship between Islamic leadership and job performance. Moreover, organizational commitment partially mediated the relationship between Islamic leadership and job performance.
Originality/value
Previous studies on Islamic leadership contain a very little number of empirical models. This study proposes a valuable empirical model of Islamic leadership consisting of moral values, spirituality, ethics and wisdom. In addition, the proposed model is supported with empirical pieces of evidence. Evidence of the partial mediating role of organizational commitment between Islamic leadership and job performance is also revealed by the study.
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This study aimed to explore the adaptations and perspectives of hotel managers regarding green and smart hotel technologies within the context of sustainability.
Abstract
Purpose
This study aimed to explore the adaptations and perspectives of hotel managers regarding green and smart hotel technologies within the context of sustainability.
Design/methodology/approach
A comprehensive literature review guided the formulation of this study, followed by face-to-face, semi-structured interviews with hotel managers. A total of 17 prepared questions were finalized after examination by two expert academicians. The responses were analyzed using qualitative research methodology and the results were weighted using the step-wise weight assessment ratio analysis (SWARA) method.
Findings
Interviews with sustainability and operational managers yielded insights into environmentally friendly practices and strategies such as reducing energy and water consumption, waste and chemical reduction, supporting local entrepreneurs and adopting smart technologies. These factors are crucial in eco-friendly hotels. According to the SWARA analysis, 'reducing energy consumption' is the most effective criterion.
Research limitations/implications
This study offers insights into green and smart hotel management by focusing on the perspectives of hotel managers with a small sample. In future studies, research with larger samples on customer perspectives and the effect of hotel selection is recommended.
Practical implications
This study offers insights to hotel managers on energy conservation and customer satisfaction enhancement through green and technological applications. These technological applications can improve hotel service quality and provide personalized experiences, fostering customer loyalty.
Originality/value
This pioneering study focuses on the intersection of green and smart practices in hospitality. By intertwining the often separately discussed concepts of “green” and “smart,” this study presents a novel approach to the sustainability practices in the hospitality industry, holding a key position, especially in Turkey. Implementing these concepts can yield environmental and economic benefits, offering invaluable insights to hotel managers and policymakers into integrating smart technologies with sustainability.
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Frank Nana Kweku Otoo, Prince Nti Adjei Junior, George Aboagye Agyeman and Regina Bekoe
Learning capability improves knowledge resources fosters innovative capabilities and firm competitiveness. The study aims to examine the human resource management (HRM) practice…
Abstract
Purpose
Learning capability improves knowledge resources fosters innovative capabilities and firm competitiveness. The study aims to examine the human resource management (HRM) practice and employee creativity relationship using organizational learning capability (OLC) as a mediating variable.
Design/methodology/approach
Data were collected from 67 small-sized and 96 medium-sized firms. Confirmatory factor analysis was applied to establish construct validity and reliability. Structural equation modeling was used to evaluate the proposed model and hypotheses.
Findings
The results show that performance appraisal and employee creativity were positively related. Employee participation and employee creativity were positively related. Compensation and employee creativity were nonsignificantly related. OLC mediates the performance appraisal and employee creativity relationship. Similarly, OLC mediates the employee participation and employee creativity relationship. However, OLC did not mediate the compensation and employee creativity relationship.
Research limitations/implications
Due to the research’s SME focus and cross-sectional data, the finding’s generalizability will be constrained.
Practical implications
The findings of the study would be useful to policymakers, stakeholders and management of SMEs in developing a supportive learning climate that promotes experiential and continuous learning cultures to ensure strategic capabilities, sustainable competitive advantage and innovativeness.
Originality/value
The study contributes to the extant literature on OLC, HRM practices and employee creativity by empirically evidencing that OLC mediates the performance appraisal, employee participation and employee creativity relationship.
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Florence Dadzoe, Michael Addy, Daniel Yaw Addai Duah and Michael Adesi
To be able to achieve the uptake and usage of green buildings requires various actors within the construction value chain to be engaged. Despite its global uptake, green building…
Abstract
Purpose
To be able to achieve the uptake and usage of green buildings requires various actors within the construction value chain to be engaged. Despite its global uptake, green building construction is still at its nascent stage in Ghana. Most studies in sub-Saharan Africa point to the lack of knowledge as one of the mitigating factors against its development. However, there is a dearth of studies assessing the level of knowledge of stakeholders. The terms “knowledge” and “awareness” of green building construction are often used interchangeably in the Ghanaian Construction Industry (GCI). This study seeks to unearth the level of knowledge of stakeholders on green building construction through a comparative analysis of construction professionals and demand-side operators.
Design/methodology/approach
A structured questionnaire was issued to professionals in the various recognised bodies in the construction industry and public and private institutions in Ghana. Frequency, Kolmogorov–Smirnov test, median statistics and Mann–Whitney U-Test were used to rank and analyse the level of knowledge of stakeholders.
Findings
Construction professionals were more aware of green building construction than the demand-side operators. It was further identified that only a few of these stakeholders had hands-on experience as the majority of them have gained their awareness through research studies. Based on the findings of the study, it was revealed that the concept of green building construction is more abstract to stakeholders than practical despite their positive attitude towards its adoption.
Practical implications
Contextually, the study has aided in showing the level of knowledge of stakeholders on green building construction. The findings of the study aside from it aiding policymakers have also helped in identifying the perceptions and attitudes of stakeholders, their strengths and weakness in green building construction. It is recommended that due to the differences in socio-political structures and construction methods, a clear definition of green building based on the availability of resources in the GCI will encourage its adoption.
Originality/value
The study used two stakeholder groupings in the GCI as the unit of analysis. This enabled insightful discoveries into the knowledge-attitude gap of Ghanaian stakeholders that are driving the adoption of green building.