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Article
Publication date: 3 May 2023

Göksel Behret, Oguzhan Sahin and Veysel Erturun

The purpose of this study is to investigate the effects of graphene nanoplates (GNPs), and alloying time on aluminum matrix composite. After mixing the powdered materials in the…

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Abstract

Purpose

The purpose of this study is to investigate the effects of graphene nanoplates (GNPs), and alloying time on aluminum matrix composite. After mixing the powdered materials in the alloying device, solid samples were formed by sintering. It is thought that the effect of using such a mechanical mixer on GNPs will be investigated and this study will give a perspective on the composites that GNPs will make with Al and its alloys.

Design/methodology/approach

Mechanical alloying (MA) device capable of high-speed shaking (Spex) movement was used and alloying was performed by adding other metal powders into aluminum, which is the matrix material, with the addition of GNPs at three different rates and times. The crystal size and lattice stress parameters were calculated by obtaining the X-ray diffraction (XRD) graphics of the obtained powder mixtures.

Findings

The XRD graphs of the obtained powder mixtures showed that the Al peaks decreased when the MA time increased. When the scanning electron microscopy images of the powder mixtures were examined, it was observed that agglomeration occurred especially in 1 and 1.5 Wt.% graphene reinforced mixtures that were MA for 90 min. The increase in the amount of graphene had a negative effect on the homogeneous distribution. When the Vickers microhardness values of the samples were examined, the hardness value of all samples increased up to the MA time of 45 min, and decreased in the times over 45 min.

Originality/value

The use of GNPs in the mechanical alloying technique and the fact that this technique was performed on the Retsch MM 400 device, which is a Spex type mixer, shows the originality of the study in terms of time and material content.

Details

Aircraft Engineering and Aerospace Technology, vol. 95 no. 7
Type: Research Article
ISSN: 1748-8842

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Publication date: 4 April 2024

Caroline Fell Kurban and Muhammed Şahin

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Abstract

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The Impact of ChatGPT on Higher Education
Type: Book
ISBN: 978-1-83797-648-5

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Book part
Publication date: 5 October 2020

Hasan Cinnioğlu

The current Industry 4.0 era is considered not only as a process that dominates technological developments but also as a process that influences the leadership styles. Management…

Abstract

The current Industry 4.0 era is considered not only as a process that dominates technological developments but also as a process that influences the leadership styles. Management 4.0 is essential for businesses to find and apply the appropriate technologies in the age of Industry 4.0. The leadership styles that business managers will adopt in order to be successful in this process and to survive in an intensely competitive environment can play an important role. At this point, a significant problem arises: identifying leadership styles that will bring success. In this context, the primary purpose of this chapter is to explain the modern leadership styles that business managers can adopt or follow in the age of Industry 4.0. In line with this purpose, the chapter first describes the historical development of leadership, leadership theories and modern leadership styles, such as transactional, transformational, technological, strategic, visionary and agile leadership, and all these concepts are discussed based on the Industry 4.0 perspective.

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Book part
Publication date: 25 September 2023

Mehmet Bağış, Mehmet Nurullah Kurutkan and Liridon Kryeziu

This research aims to determine the contribution of publications in the context of Türkiye to the international entrepreneurship literature between 2005 and 2022. We examined 471…

Abstract

This research aims to determine the contribution of publications in the context of Türkiye to the international entrepreneurship literature between 2005 and 2022. We examined 471 articles published in international journals in the Web of Science (WoS) Core Collection database using bibliometric analysis techniques. We analyzed the data with the software Biblioshiny+Bibliometrix, SciMAT, and VOSViewer. We used performance, theme and evolution, co-authorship, and document analysis in data analysis. Performance analysis findings show that the most publications were made in 2021, the journal with the most publications was sustainability, and the author with the most publications was Bakır, C. Theme and evolution analysis revealed that the motor themes were corporate entrepreneurship, gender and entrepreneurial intentions in the first period (2005–2014), while institutional entrepreneurship stood out as the niche theme. In the second period (2015–2022), “corporate entrepreneurship” and “performance” emerged as the motor themes, while the niche themes in this period were “Syrian refugees” and “entrepreneurial intentions.” Document analysis findings show that the most studied entrepreneurship types are gender, family, corporate, social, and small business, respectively. In addition, immigrant/refugee entrepreneurship is emerging as a new topic, while indigenous entrepreneurship, informal entrepreneurship, sustainable entrepreneurship, and religion entrepreneurship are the most minor studied topics in entrepreneurship. Evidence-based decision-making inputs were obtained for those holding the resource allocation authority in Türkiye. Policymakers and funders, as well as individuals and institutions that want to design the future in terms of resources, can benefit from the findings and analysis of this chapter. Türkiye, which ranks 26th in the world regarding entrepreneurship, must develop a policy based on data.

Details

Entrepreneurship Development in the Balkans: Perspective from Diverse Contexts
Type: Book
ISBN: 978-1-83753-455-5

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Article
Publication date: 18 October 2021

Zafer Bingul and Oguzhan Karahan

The purpose of this paper is to address a fractional order fuzzy PID (FOFPID) control approach for solving the problem of enhancing high precision tracking performance and…

503

Abstract

Purpose

The purpose of this paper is to address a fractional order fuzzy PID (FOFPID) control approach for solving the problem of enhancing high precision tracking performance and robustness against to different reference trajectories of a 6-DOF Stewart Platform (SP) in joint space.

Design/methodology/approach

For the optimal design of the proposed control approach, tuning of the controller parameters including membership functions and input-output scaling factors along with the fractional order rate of error and fractional order integral of control signal is tuned with off-line by using particle swarm optimization (PSO) algorithm. For achieving this off-line optimization in the simulation environment, very accurate dynamic model of SP which has more complicated dynamical characteristics is required. Therefore, the coupling dynamic model of multi-rigid-body system is developed by Lagrange-Euler approach. For completeness, the mathematical model of the actuators is established and integrated with the dynamic model of SP mechanical system to state electromechanical coupling dynamic model. To study the validness of the proposed FOFPID controller, using this accurate dynamic model of the SP, other published control approaches such as the PID control, FOPID control and fuzzy PID control are also optimized with PSO in simulation environment. To compare trajectory tracking performance and effectiveness of the tuned controllers, the real time validation trajectory tracking experiments are conducted using the experimental setup of the SP by applying the optimum parameters of the controllers. The credibility of the results obtained with the controllers tuned in simulation environment is examined using statistical analysis.

Findings

The experimental results clearly demonstrate that the proposed optimal FOFPID controller can improve the control performance and reduce reference trajectory tracking errors of the SP. Also, the proposed PSO optimized FOFPID control strategy outperforms other control schemes in terms of the different difficulty levels of the given trajectories.

Originality/value

To the best of the authors’ knowledge, such a motion controller incorporating the fractional order approach to the fuzzy is first time applied in trajectory tracking control of SP.

Details

Industrial Robot: the international journal of robotics research and application, vol. 49 no. 4
Type: Research Article
ISSN: 0143-991X

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