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Article
Publication date: 4 September 2017

Yan Li, Zhi Xin Ba, Yong Liang Li, Yan Ge and Xi Chang Zhu

This paper aims to investigate the inhibition effect of sodium silicate (SS), sodium alginate (SA) and sodium tungstate (ST) on the corrosion behavior of AZ91D magnesium…

Abstract

Purpose

This paper aims to investigate the inhibition effect of sodium silicate (SS), sodium alginate (SA) and sodium tungstate (ST) on the corrosion behavior of AZ91D magnesium alloy in 3.5 per cent NaCl solution through polarization curve test at room temperature, electrochemical impedance spectroscopy and weight loss measurement.

Design/methodology/approach

The influence of SA concentration on the inhibition efficiency of the corrosion inhibitor was mainly analyzed. The corrosion morphology and inhibition mechanism of the samples were also analyzed with scanning electron microscopy and energy-dispersive spectroscopy.

Findings

The results show that with the increase of SA concentration, the corrosion inhibition first increases and then decreases. When SA concentration is 0.03 mol/L, the inhibition efficiency is the highest, reaching 98 per cent. The adsorption film formed by SA and other deposition films produce a synergistic effect on the improvement of corrosion resistance of AZ91D magnesium alloy.

Originality/value

The adsorption film formed by SA with other deposition films produces a synergistic effect on the improvement of corrosion resistance of AZ91D magnesium alloy. With the increase of SA concentration, the corrosion inhibition first increases and then decreases. When the concentrations of SA, SS and ST are 0.03 mol/L, 0.015 mol/L and 0.02 mol/L, respectively, the inhibition efficiency of the inhibitor is the highest, reaching 98 per cent.

Details

Anti-Corrosion Methods and Materials, vol. 64 no. 5
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 16 October 2018

Wenxiong Lin, Huagang Liu, Haizhou Huang, Jianhong Huang, Kaiming Ruan, Zixiong Lin, Hongchun Wu, Zhi Zhang, Jinming Chen, Jinhui Li, Yan Ge, Jie Zhong, Lixin Wu and Jie Liu

The purpose of this paper is to explore the possibility of an enhanced continuous liquid interface production (CLIP) with a porous track-etched membrane as the…

Abstract

Purpose

The purpose of this paper is to explore the possibility of an enhanced continuous liquid interface production (CLIP) with a porous track-etched membrane as the oxygen-permeable window, which is prepared by irradiating polyethylene terephthalate membranes with accelerated heavy ions.

Design/methodology/approach

Experimental approaches are carried out to characterize printing parameters of resins with different photo-initiator concentrations by a photo-polymerization matrix, to experimentally observe and theoretically fit the oxygen inhibition layer thickness during printing under conditions of pure oxygen and air, respectively, and to demonstrate the enhanced CLIP processes by using pure oxygen and air, respectively.

Findings

Owing to the high permeability of track-etched membrane, CLIP process is demonstrated with printing speed up to 800 mm/h in the condition of pure oxygen, which matches well with the theoretically predicted maximum printing speed at difference light expose. Making a trade-off between printing speed and surface quality, maximum printing speed of 470 mm/h is also obtained even using air. As the oxygen inhibition layer created by air is thinner than that by pure oxygen, maximum speed cannot be simply increased by intensifying the light exposure as the case with pure oxygen.

Originality/value

CLIP process is capable of building objects continuously instead of the traditional layer-by-layer manner, which enables tens of times improvement in printing speed. This work presents an enhanced CLIP process by first using a porous track-etched membrane to serve as the oxygen permeable window, in which a record printing speed up to 800 mm/h using pure oxygen is demonstrated. Owing to the high permeability of track-etched membrane, continuous process at a speed of 470 mm/h is also achieved even using air instead of pure oxygen, which is of significance for a compact robust high-speed 3D printer.

Details

Rapid Prototyping Journal, vol. 25 no. 1
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 7 November 2016

Juan Wen, Yinnian He and Xin Zhao

The purpose of this paper is to propose a new stabilized finite volume element method for the Navier-Stokes problem.

Abstract

Purpose

The purpose of this paper is to propose a new stabilized finite volume element method for the Navier-Stokes problem.

Design/methodology/approach

This new method is based on the multiscale enrichment and uses the lowest equal order finite element pairs P1/P1.

Findings

The stability and convergence of the optimal order in H1-norm for velocity and L2-norm for pressure are obtained.

Originality/value

Using a dual problem for the Navier-Stokes problem, the convergence of the optimal order in L2-norm for the velocity is obtained. Finally, numerical example confirms the theory analysis and validates the effectiveness of this new method.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 26 no. 8
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 25 February 2014

S. Radavičiene, M. Jucienė, V. Sacevičiene, R. Sacevičius and K. Otas

The purpose of this paper is to determine conformity of geometrical parameters between the elements embroidered with photoluminescent threads and their digital images as…

Abstract

Purpose

The purpose of this paper is to determine conformity of geometrical parameters between the elements embroidered with photoluminescent threads and their digital images as well as to explore the change in photoluminescent radiation.

Design/methodology/approach

Using some different methodologies and apparatus, analysis shape of embroidered elements conformity and photoluminescent luminance attenuation are analysed.

Findings

The provided methodologies allow assessing the quality of embroidered elements area and photoluminescent properties.

Originality/value

The proposed approach can be adjusted to investigate photoluminescent properties of embroidered elements of different filling types.

Details

International Journal of Clothing Science and Technology, vol. 26 no. 1
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 7 August 2009

Yenming Zhang and Siew Kheng Catherine Chua

Badaracco of Harvard Business School suggests a “nudge‐test‐escalate” (NTE) approach in influencing and implementing change. In The Book of Changes (I‐Ching), the most…

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Abstract

Purpose

Badaracco of Harvard Business School suggests a “nudge‐test‐escalate” (NTE) approach in influencing and implementing change. In The Book of Changes (I‐Ching), the most archaic and authoritative works of the Chinese classics, it adopts a “test‐accelerate‐forge” (TAF) approach instead. The purpose of this paper is to examine the similarities and differences between these two models, and addresses the effectiveness of influential leadership when the models are used in the western and eastern settings, respectively. It also looks at the fundamental concepts that underlie the models and discusses the characteristics and virtues that an influential leader must possess in order to make change happen.

Design/methodology/approach

The paper reviews the Harvard model by Badaracco and extracts taken from I‐Ching. It makes comparisons between the Chinese and Western perspectives.

Findings

The paper provides a discussion on the NTE and the TAF three‐step approaches in their leadership style to understand how western and Chinese leaders exert their power of influence. This paper argues that although each adopts a three‐step approach in its leadership style, the differences lie in the philosophies that are used to guide the leader in influencing others. From the Western perspective, there are three pertinent virtues of “restraint, modesty, and tenacity” in pushing through change, while the Chinese adopt the three virtues of “prudence, balance, and authority” as their essential guide in leadership and by exercising self‐restraint and patience, resonance, and balancing.

Practical implications

The paper presents the pertinence and applicability of the Harvard model and the Chinese model since there is an increase of frequency of cross‐cultural communication in government, business, education, and other organisations. One of the trends in research on leadership is on leaders' quality in relation to organisational ethics and competencies of effective communication.

Originality/value

This paper presents a high level of comparative analyses between two influential models. It points out the need for leaders in both the western and Asian organisations to be aware of the two models so as to enhance their competencies and capacities in maximising change. This paper argues that Harvard model is well designed and highly applicable; and that the Chinese classics on influential leaders are still relevant in today's contexts.

Details

Chinese Management Studies, vol. 3 no. 3
Type: Research Article
ISSN: 1750-614X

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Article
Publication date: 16 October 2018

Ya Qian, Wentao Yan and Feng Lin

This paper aims to study the effect of processing parameters and the fundamental mechanism of surface morphologies during electron beam selective melting.

Abstract

Purpose

This paper aims to study the effect of processing parameters and the fundamental mechanism of surface morphologies during electron beam selective melting.

Design/methodology/approach

From the powder-scale level, first, the discrete element method is used to obtain the powder bed distribution that is comparable with the practical condition; then, the finite volume method is used to simulate the particle melting and flowing process. A physically reliable energy distribution of the electron beam is applied and the volume of fluid method is coupled to capture the free boundary flow. Twelve sets of parameters grouped into three categories are examined, focusing on the effect of scan speed, input powder and energy density.

Findings

According to the results, both melting pool width and depth have a positive relation with the energy density, whereas the melting pool length is insensitive to the scan velocity change. The balling effect is attributed to either an insufficient energy input or the flow instability; the hump effect originates from the mismatch between electron beam moving and the fluid flow. The scan speed is a key parameter closely related to melting pool size and surface morphologies.

Originality/value

Through a number of case studies, this paper gives a comprehensive insight of the parameter effects and mechanisms of different surface morphologies, which helps to better control the manufacturing quality of electron beam selective melting.

Details

Rapid Prototyping Journal, vol. 24 no. 9
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 4 September 2017

R.D. Zhu, Y.H. Wang, N.G. Wang, L.N. Zhang, A. Lu, M.J. Wang and X. Liu

This paper aims to introduce a novel approach to the fabrication of photoluminescent materials by coating rare earth aluminate luminescent materials on metallic substrates…

Abstract

Purpose

This paper aims to introduce a novel approach to the fabrication of photoluminescent materials by coating rare earth aluminate luminescent materials on metallic substrates and a readily manufacturable light source with robust structure in the form of photoluminescent sphere (APS).

Design/methodology/approach

The clean and dried stainless steel sphere was sprayed with UH 2593, a white undercoat, the luminescent coating and the weather resistance coating in chronological order.

Findings

After adhered onto the stainless steel sphere, the peaks corresponding to the N-H stretching vibrations were changed. The intensity of free N-H stretching at 3,536 cm−1 dramatically decreased and the peak of hydrogen-bonded N-H stretching of PU moved to lower wavenumbers. The red shift of the infrared bands of functional groups was attributed to the strengthened hydrogen bonding. The hydrogen bonding interactions between the stainless steel substrates and the polyurethane coating endowed the APS with excellent adhesive property and also promoted the evenly distribution of the photoluminescent particles in the polymer coating matrix.

Practical implications

This approach can be applicable in the fabrication of the photoluminescent materials. The APS can be used as signs and guiding post in remote areas without sufficient electricity supply and in the seas and rivers with complicated hydrological conditions.

Originality/value

This approach has provided a method to produce tough and durable luminescent signs for remote areas and dangerous seas and explained the functional mechanism of the combined application of metallic materials and non-metallic materials.

Details

Pigment & Resin Technology, vol. 46 no. 5
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 11 June 2020

Shaoze Lu, Jun Huang and Mingxu Yi

By reducing the coating thickness of the weak scattering source, the coating weight of the absorbing material can be reduced by 35% with little effect on the RCS.

Abstract

Purpose

By reducing the coating thickness of the weak scattering source, the coating weight of the absorbing material can be reduced by 35% with little effect on the RCS.

Design/methodology/approach

To alleviate the weight-increasing problem caused by a large number of coating of absorbing materials, a method for zonal coating of absorbing materials for a stealth helicopter was proposed. By appropriately reducing the thickness of the coating at the secondary scattering locations, the amount of coating used is significantly reduced.

Findings

Compared with the full-coated, the zonal coating scheme achieves the corresponding RCS reduction effect.

Practical implications

Zonal coating design can achieve the effect of reducing coating weight and cost.

Originality/value

The effects of different coating methods on RCS were verified by electromagnetic scattering simulation, and the applicability of the zonal coating design of the absorbing material to the stealth helicopter was verified.

Details

Aircraft Engineering and Aerospace Technology, vol. 92 no. 7
Type: Research Article
ISSN: 1748-8842

Keywords

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Book part
Publication date: 23 June 2016

Abstract

Details

Essays in Honor of Aman Ullah
Type: Book
ISBN: 978-1-78560-786-8

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Article
Publication date: 7 November 2016

Galal H. Elgemeie and Doaa M. Masoud

This paper aims to focus on the most popular technique nowadays, the use of microwave irradiation in organic synthesis; in a few years, most chemists will use microwave…

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1187

Abstract

Purpose

This paper aims to focus on the most popular technique nowadays, the use of microwave irradiation in organic synthesis; in a few years, most chemists will use microwave energy to heat chemical reactions on a laboratory scale. Also, many scientists use microwave technology in the industry. They have turned to microwave synthesis as a frontline methodology for their projects. Microwave and microwave-assisted organic synthesis (MAOS) has emerged as a new “lead” in organic synthesis.

Design/methodology/approach

Using microwave radiation for synthesis and design of fluorescent dyes is of great interest, as it decreases the time required for synthesis and the synthesized dyes can be applied to industrial scale.

Findings

The technique offers many advantages, as it is simple, clean, fast, efficient and economical for the synthesis of a large number of organic compounds. These advantages encourage many chemists to switch from the traditional heating method to microwave-assisted chemistry.

Practical implications

This review highlights applications of microwave chemistry in organic synthesis for fluorescent dyes. Fluorescents are a fairly new and very heavily used class of organics. These materials have many applications, as a penetrant liquid for crack detection, synthetic resins, plastics, printing inks, non-destructive testing and sports ball dyeing.

Originality/value

The aim value of this review is to define the scope and limitation of microwave synthesis procedures for the synthesis of novel fluorescent dyes via a simple and economic way.

Details

Pigment & Resin Technology, vol. 45 no. 6
Type: Research Article
ISSN: 0369-9420

Keywords

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