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Article
Publication date: 26 March 2019

Mikiale Gebreslase Gebremariam, Yuming Zhu, Naveed Ahmad and Dawit Nega Bekele

The increasing African population and economic growth leading to urbanisation continues to increase the need to redevelop brownfields as a strategy of encouraging…

Abstract

Purpose

The increasing African population and economic growth leading to urbanisation continues to increase the need to redevelop brownfields as a strategy of encouraging sustainable development of cities, in particular in Ethiopia. However, the adoption of brownfield redevelopment in Ethiopia is at initial stage. Thus, the purpose of this paper is to highlight the framework based on grey-incidence decision-making approach to manage brownfields in African countries by taking Ethiopia as case example. The grey-incidence decision-making model integrates multiple factors such as economic, social, environmental, technical and associated risks and provides an effective decision-making and management tool for environmental practitioners and government agencies.

Design/methodology/approach

Questionnaires were used to collect data on terms and definitions of brownfield. The questions were prepared on the basis of currently used definitions developed by a number of developed countries. Moreover, this study utilises a grey-incidence decision-making approach to help in management and decision-making for the implementation of brownfield redevelopment projects (BRPs) in the remediated sites.

Findings

Standard definition of brownfield and essential guidelines for brownfield redevelopment is proposed for Ethiopian context. The research findings were tested and verified using literature data and survey from major stakeholders. In addition, the grey-incidence decision-making approach is applied for the evaluation of BRPs in the remediated sites. A framework is proposed to control future brownfields for African countries by taking Ethiopia as a case example.

Originality/value

This research stresses the significance of an urban structure to address sustainable development, and the need to consider redevelopment of brownfields and identify the potential for a specific government policy framework. This research provides the best opportunity for Ethiopia by devising an urban land policy and create a strategy to contribute social, economic, financial and environmental benefits. It also provides a foundation to solve environmental issues by involving all major stakeholders, including community citizens, environmentalists and government agencies, and it also serves as guidelines to transform brownfields into Greenfields; and finally, it contributes to achieve the 2030 UN global goals.

Details

World Journal of Science, Technology and Sustainable Development, vol. 16 no. 3
Type: Research Article
ISSN: 2042-5945

Keywords

Article
Publication date: 17 August 2012

Yuming Zhu, Rongrong Wang and Keith W. Hipel

The purpose of this paper is to propose an evaluation model for evaluating the innovation competency in the Yanliang Aviation Industry Park, which is a typical example of…

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Abstract

Purpose

The purpose of this paper is to propose an evaluation model for evaluating the innovation competency in the Yanliang Aviation Industry Park, which is a typical example of an aviation industry cluster.

Design/methodology/approach

A subjective weighting method based on the order relation is used to determine the index weights, which are utilized in grey incidence analysis to measure the innovation competency of the aviation industry cluster.

Findings

The application of the index methodology to the Yanliang Aviation Industry Park demonstrates that the industry cluster possesses a strong innovation competency, as well as the feasibility and practicability of employing this approach.

Practical implications

The method introduced in the paper can be used to solve practical problems. Moreover, it provides potential support for the development of the aviation industry in the future.

Originality/value

In this paper, the high technology aviation industry, which now plays a strategic industrial role in China, is systematically studied by using a new methodology based on grey systems. Additionally, a subjective weighting sequence model founded upon a grey relational analysis is utilized in place of the analytic hierarchy process (AHP).

Details

Grey Systems: Theory and Application, vol. 2 no. 2
Type: Research Article
ISSN: 2043-9377

Keywords

Article
Publication date: 11 June 2018

Yuming Guan, Jingbo Mu, Hongwei Che, Xiaoliang Zhang and Zhixiao Zhang

The purpose of this study is to design carbon electrode materials for high performance electric double-layer capacitors (EDLCs) with pores that are large enough and have…

Abstract

Purpose

The purpose of this study is to design carbon electrode materials for high performance electric double-layer capacitors (EDLCs) with pores that are large enough and have suitable pore size distribution for the electrolyte to access completely to improve EDLCs’ electrochemical performance.

Design/methodology/approach

This study develop an improved traditional KOH activation method, and a series of micro-meso hierarchical porous carbons have been successfully prepared from phenol formaldehyde resin by combining polyethylene glycol (PEG) and conventional KOH activation.

Findings

As evidenced by N2 adsorption/desorption tests, the obtained samples present Types IV and I-IV hybrid shape isotherms compared with KOH-activated resin (typical of Type I). The sample AC2-7-1, which the addition quantity of PEG is 25 per cent PF (weight ration) activated at 700? For 1 h is considered as the optimum preparation condition. It exhibits the highest specific capacitance value of 240 F/g in 30 wt% KOH aqueous electrolytes because of its higher specific surface area (2085 m2/g), greater pore volume (1.08 cm3/g) and the maximum mesoporosity (43 per cent). In addition, the capacity decay of this material is only 3.1 per cent after 1000 cycles.

Originality/value

The materials that are rich in micropores and mesopores show great potential in EDLC capacitors, particularly for applications where high power output and good high-frequency capacitive performances are required.

Details

World Journal of Engineering, vol. 15 no. 3
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 5 March 2018

Boya Ji, Yuming Liu and Zhanyong Jin

The purpose of this paper is to utilise a “Wuli-Shili-Renli (WSR)” system approach to create models for complex smart building energy management and evaluate the…

Abstract

Purpose

The purpose of this paper is to utilise a “Wuli-Shili-Renli (WSR)” system approach to create models for complex smart building energy management and evaluate the establishment of a building energy management platform.

Design/methodology/approach

The complexity and diversity of the data and demands of the energy management platform mean that it is necessary to analyse comprehensively. This paper uses a WSR system approach to handle, and optimise, the relationship between demands and participants and improve the whole platform. Then, this paper establishes comprehensive evaluation models to analysis the current energy management platforms by using the best integration platform as the baseline.

Findings

The WSR conceptual model clarifies the relationship between the elements and elements of the energy management platform clearly and provides the appropriate analytical methods with which to resolve key platform construction issues. The comprehensive evaluation based on a WSR system approach can take into account the systematic effect, so it is more accurate.

Research limitations/implications

The correlation degree between the layers of the energy management platform is rarely reflected.

Originality/value

This paper improves the modelling method used in the WSR system approach and demonstrates that the comprehensive evaluation based on the WSR system approach analyses the energy management platform for public buildings in a synthetic approach.

Article
Publication date: 11 July 2018

Xin Liu, Yuming Xing and Liang Zhao

The purpose of this study is to investigate structure parameters that influence the mixing process of droplets-gas in underwater depth-adjustable launcher cooling chamber…

Abstract

Purpose

The purpose of this study is to investigate structure parameters that influence the mixing process of droplets-gas in underwater depth-adjustable launcher cooling chamber and help engineers who design the launcher to distinguish the most important factor that impacts mixing performance in the cooling chamber.

Design/methodology/approach

Euler–Lagrangian droplet tracking method was used to simulate droplets-gas mixing process in the cooling chamber. The SST k-w model was adopted to simulate turbulence. Droplet breakup was described by KHRT hybrid model using modified contains which are more fit to the supersonic main flow condition.

Findings

The results show the counter-rotating vortex pairs which caused by injected liquid accelerate the mixing process. High-pressure supersonic freestream makes the liquid jet break into more small droplets due to the high momentum of the main stream. Axial injection angle has the greatest influence on Sauter mean diameter (SMD). Penetration height, SMD and total pressure loss slightly change in different tangential injection conditions. However, mixedness decreases with reduction of tangential injection angle due to a more limited space for spray developing. Enlarging orifice diameter raises penetration and mixedness greatly, while SMD and total pressure loss increase slightly.

Originality/value

The findings of this study confirm the key structure parameter to improve mixing performance in the cooling chamber. Engineers who design the underwater depth-adjustable launcher can refer the findings in this study to make control of launching power more accurate.

Details

Engineering Computations, vol. 35 no. 5
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 18 August 2022

Hangjia Dong, Tuanjie Li, Zuowei Wang and Yuming Ning

The inchworm actuator is widely applied in space industry. One of the major issues in space instrumentation is the reliability, especially under space thermal load. The…

Abstract

Purpose

The inchworm actuator is widely applied in space industry. One of the major issues in space instrumentation is the reliability, especially under space thermal load. The purpose of this paper is to present a numerical calculation method for the inchworm actuator reliability with considering the effect of space temperature.

Design/methodology/approach

First, the structure of designed inchworm actuator is introduced, and the main failure reason is analyzed. Then the wear model is proposed with considering the space temperature, and an experiment device is designed to verify the wear model. Finally, the reliability calculation method is developed based on the working principle of the inchworm actuator.

Findings

The numerical calculation method can be applied to calculate the reliability of the inchworm actuator with considering the space temperature. And the results provide a new perspective to discuss the influences of the temperature and driving voltage on the reliability of inchworm actuators.

Originality/value

This work presents a reliability calculation method of inchworm actuators with considering the space temperature.

Details

Aircraft Engineering and Aerospace Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 23 November 2020

Sheng Chen, Yuming Xing, Xin Liu and Liang Zhao

The purpose of this study is to investigate the effect of the injection angle α on the spray structures of an air-blast atomizer and help enhance the understanding of…

Abstract

Purpose

The purpose of this study is to investigate the effect of the injection angle α on the spray structures of an air-blast atomizer and help enhance the understanding of droplet-gas mixing process in such atomizers in the engineering domain.

Design/methodology/approach

The phenomena in the air-blast atomizer were numerically modelled using the computational fluid dynamics software Fluent 17.2. The Euler-Lagrange approach was applied to model the droplet tracking and droplet-gas interaction in studied cases. The standard k-ε model was used to simulate the turbulent flow. A model with a modified drag coefficient was used to consider the effects of the bending of the liquid column and its penetration in the primary breakup region. The Kelvin-Helmholtz, Rayleigh-Taylor model was applied to consider the secondary breakup of the droplets.

Findings

The basic spatial distribution and spray structures of the droplets corresponding to the angled liquid jet (α = 60°) were similar to those reported in liquid jets injected transversely into a gaseous crossflow studies. The injection angle α did not considerably influence the averaged Sauter to mean diameter (SMD) of the cross-sections. However, the spray structures pertaining to α = 30°, α = 60° and α = 90° were considerably different. In the case of the atomizer with multiple injections, a “collision region” was observed at α = 60° and characterized by a higher ci and larger averaged SMD in the central parts of the cross-sections.

Originality/value

The injection angle α is a key design parameter for air-blast atomizers. The findings of this study can help enhance the understanding of the droplet-gas mixing process in air-blast atomizers. Engineers who design air-blast atomizers and face new challenges in the process can refer to the presented findings to obtain the desired atomization performance. The code has been validated and can be used in the engineering design process of the gas-liquid jet atomizer.

Details

Engineering Computations, vol. 38 no. 5
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 21 April 2022

Kunyong Chen, Yong Zhao, Yuming Liu, Haidong Yu and Shunzhou Huang

This paper aims to propose an optimization method to automatically adjust the spatial route of multibend pipes to meet the assembly demands in constrained space.

Abstract

Purpose

This paper aims to propose an optimization method to automatically adjust the spatial route of multibend pipes to meet the assembly demands in constrained space.

Design/methodology/approach

The compact geometric parameters that uniquely determine the pipe route are analyzed. Besides, the relationship between these parameters and the end pose is revealed based on the exponential product formula. Mathematical representations for the engineering constraints, including the end pose restriction, collision interference, manufacture ability and geometric limitations, are further established. On this basis, the adjustment of the spatial route is formulated as a multiconstraint optimization problem. A modified particle swarm optimization method based on the combination of gradient projection and swarm intelligence is designed to find the near-optimal pipe that meets the required assembly demands.

Findings

The experimental results show that the proposed method can effectively find the feasible pipe route that satisfies the engineering constraints and the end pose requirement is highly guaranteed.

Originality/value

The proposed method can automate the geometric adjustment of multi-bend pipes to meet the actual assembly demands, which significantly reduces manual efforts and guarantees high accuracy. The results demonstrate the possibility of further applications in the pipe assembly or design process, especially in ships, aerospace products or pressure vessels.

Details

Assembly Automation, vol. 42 no. 3
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 13 November 2017

Zhixiang Song, Fei Guo, Ying Liu, Songtao Hu, Xiangfeng Liu and Yuming Wang

This paper aims to present the slip/no-slip design in two-dimensional water-lubricated tilting pad thrust bearings (TPTBs) considering the turbulence effect and shifting…

Abstract

Purpose

This paper aims to present the slip/no-slip design in two-dimensional water-lubricated tilting pad thrust bearings (TPTBs) considering the turbulence effect and shifting of pressure centers.

Design/methodology/approach

A numerical model is established to analyze the slip condition and the effect of turbulence according to a Reynolds number defined in terms of the slip condition. Simulations are carried out for eccentrically and centrally pivoted bearings and the influence of different slip parameters is discussed.

Findings

A considerable enhancement in load capacity, as well as a reduction in friction, can be achieved by heterogeneous slip/no-slip surface designs for lubricated sliding contacts, especially for near parallel pad configurations. The optimized design largely depends on the pivot position. The load capacity increases by 174 per cent for eccentrically pivoted bearings and 159 per cent for centrally pivoted bearings for a suitable design. When slip zone locates at the middle of the radial direction or close to the inner edge, the performance of the TPTB is better.

Research limitations/implications

The simplification of slip effect on the turbulence (definition of Reynolds number) can only describe the trend of the increasing turbulence due to slip condition. The accurate turbulence expression considering the boundary slip needs further explorations.

Originality/value

The shifting of pressure center due to the slip/no-slip design for TPTBs is investigated in this study. The turbulence effect and influence of slip parameters is discussed for large water-lubricated bearings.

Details

Industrial Lubrication and Tribology, vol. 69 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 28 August 2018

Zhanchao Wang, Fei Guo, Ying Liu, Xiangfeng Liu and Yuming Wang

This paper aims to design a new surface profile with simpler processing technology, which makes the bearing load carrying capacity (LCC) close to that of conventional…

Abstract

Purpose

This paper aims to design a new surface profile with simpler processing technology, which makes the bearing load carrying capacity (LCC) close to that of conventional tilting-pad thrust bearing.

Design/methodology/approach

The paper analyzes the LCC of the thrust pad with crown profile and designs a new profile, whose performance is similar to the crown profile. The laser method is introduced to fabricate the new profile. The profile with tiny crown height can be fabricated by the laser with the proper parameters.

Findings

It was found that there is an optimum value, which is best in terms of the capacity of tilting-pad thrust bearing reach. The new profile with proper parameters can replace the crown profile.

Originality/value

The new profile can replace the crown profile and is easier to be made. The new design method could be adopted for designing the pad surface profile of the tilting-pad thrust bearing.

Details

Industrial Lubrication and Tribology, vol. 70 no. 8
Type: Research Article
ISSN: 0036-8792

Keywords

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