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Article
Publication date: 9 January 2009

K. Jafarzadeh, T. Shahrabi, S.M.M. Hadavi and M.G. Hosseini

The paper aims to focus on the recognition of corrosion product morphologies of AA5083‐H321 corroding aluminum‐magnesium alloys used in the manufacture of aluminum high speed…

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Abstract

Purpose

The paper aims to focus on the recognition of corrosion product morphologies of AA5083‐H321 corroding aluminum‐magnesium alloys used in the manufacture of aluminum high speed boats and submarines during flow induced corrosion in seawater.

Design/methodology/approach

All experiments were conducted in a 3.5 percent NaCl solution as the simulated marine environment. Hydrodynamic conditions were created by an rotating cylinder electrode (RCE) system. Morphological characterization of the surface was undertaken using SEM and EDAX techniques. Cyclic polarization tests were used to determine the electrochemical behavior of the alloy.

Findings

The results obtained reveal that the pit density on the sample surface increased with increasing the rotation speed. The enhanced flow condition also enhanced the tendency for intermetallic particles, including submicron size Al(Mg,Mn) inclusions, to promote pitting corrosion of the alloy. An interesting result was that crystallographic pitting occurred at rotation speeds greater than 5 m/s.

Practical implications

In the selection of corrosion control methods for high speed aluminum‐hulled boats, control of erosion corrosion was determined to be more important than any other form of corrosion.

Originality/value

Provides information about the contribution of mechanical and electrochemical corrosion phenomena in corrosion of high speed aluminum boats under hydrodynamic conditions. Characterization of new intermetallic particles in aluminum‐magnesium alloys that can promote pitting during flow induced corrosion in marine environments. Provides new information about the origin of crystallographic pitting attack on aluminum.

Details

Anti-Corrosion Methods and Materials, vol. 56 no. 1
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 1 April 2004

K. Jafarzadeh, T. Shahrabi and S.M.M. Hadavi

The sulphidation behaviour of high contraction (HC) and low contraction (LC) chromium plated steel was studied in sulphur with a partial pressure of 1 atm at 1, 3, 5 and 7 h and…

441

Abstract

The sulphidation behaviour of high contraction (HC) and low contraction (LC) chromium plated steel was studied in sulphur with a partial pressure of 1 atm at 1, 3, 5 and 7 h and 0.1 and 0.01 atm at 5 h. The temperature was 600°C throughout the work. It was found that HC and LC chromium plating imparted significant sulphidation resistance to steel. It should be mentioned that by increasing sulphidation time and sulphur partial pressure, the hardness of chromium coating decreased. LC chromium coating had a lower thermal shock resistance than the HC coating. Thus, it was concluded that the HC chromium coating had the better sulphidation resistance.

Details

Anti-Corrosion Methods and Materials, vol. 51 no. 2
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 26 July 2011

Khairy A.H. Kobbacy and Sunil Vadera

The use of AI for operations management, with its ability to evolve solutions, handle uncertainty and perform optimisation continues to be a major field of research. The growing…

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Abstract

Purpose

The use of AI for operations management, with its ability to evolve solutions, handle uncertainty and perform optimisation continues to be a major field of research. The growing body of publications over the last two decades means that it can be difficult to keep track of what has been done previously, what has worked, and what really needs to be addressed. Hence, the purpose of this paper is to present a survey of the use of AI in operations management aimed at presenting the key research themes, trends and directions of research.

Design/methodology/approach

The paper builds upon our previous survey of this field which was carried out for the ten‐year period 1995‐2004. Like the previous survey, it uses Elsevier's Science Direct database as a source. The framework and methodology adopted for the survey is kept as similar as possible to enable continuity and comparison of trends. Thus, the application categories adopted are: design; scheduling; process planning and control; and quality, maintenance and fault diagnosis. Research on utilising neural networks, case‐based reasoning (CBR), fuzzy logic (FL), knowledge‐Based systems (KBS), data mining, and hybrid AI in the four application areas are identified.

Findings

The survey categorises over 1,400 papers, identifying the uses of AI in the four categories of operations management and concludes with an analysis of the trends, gaps and directions for future research. The findings include: the trends for design and scheduling show a dramatic increase in the use of genetic algorithms since 2003 that reflect recognition of their success in these areas; there is a significant decline in research on use of KBS, reflecting their transition into practice; there is an increasing trend in the use of FL in quality, maintenance and fault diagnosis; and there are surprising gaps in the use of CBR and hybrid methods in operations management that offer opportunities for future research.

Originality/value

This is the largest and most comprehensive study to classify research on the use of AI in operations management to date. The survey and trends identified provide a useful reference point and directions for future research.

Details

Journal of Manufacturing Technology Management, vol. 22 no. 6
Type: Research Article
ISSN: 1741-038X

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Article
Publication date: 23 February 2024

Guangwei Liang, Zhiming Gao, Cheng-Man Deng and Wenbin Hu

The purpose of this study is to reveal the effect of nano-Al2O3 particle addition on the nucleation/growth kinetics, microhardness, wear resistance and corrosion resistance of…

72

Abstract

Purpose

The purpose of this study is to reveal the effect of nano-Al2O3 particle addition on the nucleation/growth kinetics, microhardness, wear resistance and corrosion resistance of Co–P–xAl2O3 nanocomposite plating.

Design/methodology/approach

The kinetics and properties of Co–P–xAl2O3 nanocomposite plating prepared by electroplating were investigated by electrochemical measurements, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Vickers microhardness measurement, SRV5 friction and wear tester and atomic force microscopy.

Findings

A 12 g/L nano-Al2O3 addition in the plating solution can transform the nucleation/growth kinetics of the plating from the 3D progressive model to the 3D instantaneous model. The microhardness of the plating increased with the increase of nano-Al2O3 content in plating. The wear resistance of the plating did not adhere strictly to Archard’s law. An even and denser corrosion product film was generated due to the finer grains, with a high corrosion resistance.

Originality/value

The effect of different nano-Al2O3 addition on the nucleation/growth kinetics and properties of Co–P–xAl2O3 nanocomposite plating was investigated, and an anticorrosion mechanism of Co–P–xAl2O3 nanocomposite plating was proposed.

Details

Anti-Corrosion Methods and Materials, vol. 71 no. 3
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 9 August 2019

Vaira Vignesh Ramalingam, Padmanaban Ramasamy and Madhav Datta

The purpose of this study is to refine the microstructure and improve the corrosion behaviour of aluminium alloy AA5083 by subjecting it to friction stir processing (FSP).

157

Abstract

Purpose

The purpose of this study is to refine the microstructure and improve the corrosion behaviour of aluminium alloy AA5083 by subjecting it to friction stir processing (FSP).

Design/methodology/approach

FSP trials are conducted as per central composite design, by varying tool rotation speed, tool traverse speed and shoulder diameter at three levels. The microstructure is examined and the hardness is measured for both the base material and the processed workpieces. The corrosion behaviour of the base material and processed workpieces is studied using potentiodynamic polarization technique for three different testing temperatures, and the corrosion current and corrosion rate are calculated.

Findings

The results reveal that FSP refined the grains, dispersed secondary phases, increased the hardness and improved the corrosion resistance of most of the friction stir processed specimens than the base material at all the three testing temperatures. Grain refinement and fine dispersion of ß phase improves the hardness and corrosion resistance of most of the FSPed specimens. However partial dissolution of ß phase decreases the hardness in some of the specimens. Most of the FSPed specimens displayed more positive potential than the base material at all the testing temperatures representing a higher nobility than the base material, as a result of fine dispersion of secondary phase particles in the matrix. Large pits formed on the surface of the base specimen indicating a higher corrosion rate at all three testing temperatures. The SEM image of FSPed specimens reveals the occurrence of very few pits and minimal corrosion products on the surface, which indicates lower corrosion rate.

Originality/value

The corrosion mechanism of the friction stir-processed AA5083 specimens is found to be a combination of activation and concentration polarization.

Details

Anti-Corrosion Methods and Materials, vol. 66 no. 6
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 11 July 2019

Eryong Liu, Yingxin Zhang, Xiang Wang, Zhixiang Zeng, Huiling Du and Hongmei Qin

This paper aims to improve the tribocorrosion properties of 316L, thus WC/Ni60 coated 316L was prepared by thermal spraying technique.

193

Abstract

Purpose

This paper aims to improve the tribocorrosion properties of 316L, thus WC/Ni60 coated 316L was prepared by thermal spraying technique.

Design/methodology/approach

Composition and microstructure of WC/Ni60 coating was investigated, and tribological properties of 316 L and WC/Ni60 coating were studied under dry sliding, deionized water and artificial seawater.

Findings

The results showed that WC/Ni60 coating was lamellar structure, and the phase composition consisted of γ-Ni solid solution, carbides and borides. Furthermore, the hardness and corrosion resistance of 316 L in static seawater and wear resistance in dry sliding were improved by WC reinforced nickel-based coating. Furthermore, tribocorrosion results demonstrated that wear resistance of WC/Ni60 coating was also significantly better than 316 L, especially for higher load at artificial seawater. The reason can be attributed to the fact that the passive film of WC/Ni60 coating consisted of tungsten carbide, Ni(OH)2 and FeOOH for WC/Ni60 coating and only FeOOH for 316 L.

Originality/value

According to this study, it can be concluded that WC phases acted as a role in resisting the wear damages. Meanwhile, Ni-based materials performed well in corrosion resistance. Thus, the combined-effect Ni-based alloys and WC phases in WC/Ni60 coating showed better tribocorrosion performance than 316 L.

Details

Industrial Lubrication and Tribology, vol. 71 no. 6
Type: Research Article
ISSN: 0036-8792

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Book part
Publication date: 30 January 2025

Seyi S. Stephen, Ayodeji E. Oke, Clinton O. Aigbavboa, Opeoluwa I. Akinradewo, Pelumi E. Adetoro and Matthew Ikuabe

This chapter delved into the multifaceted landscape of construction partnering, exploring its key aspects, promotion factors, and associated challenges. It examined how partnering…

Abstract

This chapter delved into the multifaceted landscape of construction partnering, exploring its key aspects, promotion factors, and associated challenges. It examined how partnering principles are applied in various construction contexts, including stealth construction, where integration of advanced technologies and collaborative practices is pivotal. Moreover, it highlighted the significance of partnering in addressing crucial considerations such as environmental protection, health and safety, project delivery duration, aesthetics, and economy during and after the construction phase. Through collaborative efforts and shared responsibilities, construction partnering emerges as a cornerstone for achieving excellence and sustainability in the built environment.

Details

Stealth Construction: Integrating Practices for Resilience and Sustainability
Type: Book
ISBN: 978-1-83608-183-8

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Article
Publication date: 2 February 2023

Mahyar Khorasani, Ian Gibson, Amir Hossein Ghasemi, Elahe Hadavi and Bernard Rolfe

The purpose of this study is, to compare laser-based additive manufacturing and subtractive methods. Laser-based manufacturing is a widely used, noncontact, advanced manufacturing…

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Abstract

Purpose

The purpose of this study is, to compare laser-based additive manufacturing and subtractive methods. Laser-based manufacturing is a widely used, noncontact, advanced manufacturing technique, which can be applied to a very wide range of materials, with particular emphasis on metals. In this paper, the governing principles of both laser-based subtractive of metals (LB-SM) and laser-based powder bed fusion (LB-PBF) of metallic materials are discussed and evaluated in terms of performance and capabilities. Using the principles of both laser-based methods, some new potential hybrid additive manufacturing options are discussed.

Design methodology approach

Production characteristics, such as surface quality, dimensional accuracy, material range, mechanical properties and applications, are reviewed and discussed. The process parameters for both LB-PBF and LB-SM were identified, and different factors that caused defects in both processes are explored. Advantages, disadvantages and limitations are explained and analyzed to shed light on the process selection for both additive and subtractive processes.

Findings

The performance of subtractive and additive processes is highly related to the material properties, such as diffusivity, reflectivity, thermal conductivity as well as laser parameters. LB-PBF has more influential factors affecting the quality of produced parts and is a more complex process. Both LB-SM and LB-PBF are flexible manufacturing methods that can be applied to a wide range of materials; however, they both suffer from low energy efficiency and production rate. These may be useful when producing highly innovative parts detailed, hollow products, such as medical implants.

Originality value

This paper reviews the literature for both LB-PBF and LB-SM; nevertheless, the main contributions of this paper are twofold. To the best of the authors’ knowledge, this paper is one of the first to discuss the effect of the production process (both additive and subtractive) on the quality of the produced components. Also, some options for the hybrid capability of both LB-PBF and LB-SM are suggested to produce complex components with the desired macro- and microscale features.

Details

Rapid Prototyping Journal, vol. 29 no. 5
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 14 June 2022

Soraiya Ebrahimpour-Koujan, Amir Ali Sohrabpour, Saeid Safari, Nima Baziar, Shima Hadavi, Laleh Payahoo and Samaneh Shabani

Coronavirus disease-2019 (COVID-19) is becoming a crucial health problem worldwide. Continued and high-speed mutations of this virus result in the appearance of new…

105

Abstract

Purpose

Coronavirus disease-2019 (COVID-19) is becoming a crucial health problem worldwide. Continued and high-speed mutations of this virus result in the appearance of new manifestations, making the control of this disease difficult. It has been shown that well-nourished patients have strong immune systems who mostly have short-term hospitalization compared to others. The purpose of this study is to review the major nutrients involved in the immune system reinforcement and to explain nutritional aspects during the recovery of COVID-19.

Design/methodology/approach

In this review paper, the mechanistic role of nutrients in boosting the immune system and the nutritional aspects during the recovery of COVID-19 patients were discussed. Papers indexed in scientific databases were searched using antioxidants, COVID-19, inflammation, immune system, macronutrient, micronutrient and probiotic as keywords from 2000 to 2022.

Findings

Because of the adverse effects of drugs like thrombosis, pulmonary embolism and hypercholesterolemia, a balanced diet with enough concentrations of energy and macronutrients could increase the patient's durability. The inflammatory cytokines in a vicious cycle delay patients’ rehabilitation. The main mechanistic roles of micronutrients are attributed to the downregulation of virus replication and are involved in energy homeostasis. Dysbiosis is defined as another disturbance among COVID-19 patients, and supplementation with beneficial strains of probiotics helps to exert anti-inflammatory effects in this regard. Being on a well-planned diet with anti-inflammatory properties could reverse cytokine storms as the major feature of COVID-19. Future studies are needed to determine the safe and effective dose of dietary factors to control the COVID-19 patients.

Originality/value

Being on a well-planned diet with anti-inflammatory properties could reverse cytokine storms as the major feature of COVID-19. Future studies are needed to determine the safe and effective dose of dietary factors to control the COVID-19 patients.

Details

Nutrition & Food Science , vol. 53 no. 2
Type: Research Article
ISSN: 0034-6659

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Book part
Publication date: 16 June 2021

Aidin Salamzadeh and Veland Ramadani

The Iranian entrepreneurial ecosystem has grown dramatically during the past decade. Several improvements have been made at different levels, and, therefore, one could witness its…

Abstract

The Iranian entrepreneurial ecosystem has grown dramatically during the past decade. Several improvements have been made at different levels, and, therefore, one could witness its unique achievements. Digital entrepreneurs are an integral part of this ecosystem, as most of the early achievements are the results of their proactive behaviors. Hopefully, the number of female digital entrepreneurs has increased, and their entrepreneurial activities have profoundly changed the competition scene. Therefore, this chapter provides a better understanding of the multilayered entrepreneurial ecosystem of Iran and then elaborates how female entrepreneurs are positioned in this ecosystem. Moreover, six well-known award-winning female digital entrepreneurs are introduced, and their challenges are scrutinized accordingly through narrative research. Finally, the chapter concludes with some remarks and directions for future research.

Details

The Emerald Handbook of Women and Entrepreneurship in Developing Economies
Type: Book
ISBN: 978-1-80071-327-7

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