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Article
Publication date: 15 November 2022

Qingyang Liu, Ziyang Zhang, Denizhan Yavas, Wen Shen and Dazhong Wu

Understanding the effect of process parameters on interfaces and interfacial bonding between two materials during multi-material additive manufacturing (MMAM) is crucial to the…

486

Abstract

Purpose

Understanding the effect of process parameters on interfaces and interfacial bonding between two materials during multi-material additive manufacturing (MMAM) is crucial to the fabrication of high-quality and strong multi-material structures. The purpose of this paper is to conduct an experimental and statistical study to investigate the effect of process parameters of soft and hard materials on the flexural behavior of multi-material structures fabricated via material extrusion-based MMAM.

Design/methodology/approach

Sandwich beam samples composed of a soft core and hard shells are fabricated via MMAM under different printing conditions. A design of experiments is conducted to investigate the effect of the print speed and nozzle temperature on the flexural behavior of soft-hard sandwich beams. Analysis of variance and logistic regression analysis are used to analyze the significance of each process parameter. The interfacial morphology of the samples after the flexural tests is characterized. Thermal distributions during the MMAM process are captured to understand the effect of process parameters on the flexural behavior based on inter-bonding formation mechanisms.

Findings

Experimental results show that the soft-hard sandwich beams exhibited two different failure modes, including shell failure and interfacial failure. A transition of failure modes from interfacial failure to shell failure is observed as the nozzle temperatures increase. The samples that fail because of interfacial cracking exhibit a pure adhesive failure because of weak interfacial fracture properties. The samples that fail because of shell cracking exhibit a mixed adhesive and cohesive failure. The flexural strength and modulus are affected by the nozzle temperature for the hard material and the print speeds for both hard and soft materials significantly.

Originality/value

This paper first investigates the effect of process parameters for soft and hard materials on the flexural behavior of additively manufactured multi-material structures. Especially, the ranges of the selected process parameters are distinct, and the effect of all possible combinations of the process parameters on the flexural behavior is characterized through a full factorial design of experiments. The experimental results and conclusions of this paper provide guidance for future research on improving the interfacial bonding and understanding the failure mechanism of multi-material structures fabricated by MMAM.

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Article
Publication date: 28 August 2009

Colin Brown, Scott Waldron, Liu Yuman and John Longworth

The purpose of this paper is to show how the promotion of integrated forage/ruminant‐livestock industries forms a key plank in efforts to improve rural household livelihoods in…

574

Abstract

Purpose

The purpose of this paper is to show how the promotion of integrated forage/ruminant‐livestock industries forms a key plank in efforts to improve rural household livelihoods in Western China.

Design/methodology/approach

The paper critiques how this industry development has proceeded in the case of Qingyang prefecture in Gansu. The way in which the industry policy has manifested from central to local levels of government is outlined along with how the industry policy relates to other measures intended to improve household livelihoods.

Findings

The outcomes of this forage‐livestock industry policy do not always match the intention, and the paper examines the various disconnects that arise between government agencies, government and households and households and the market. The foremost challenge for policy makers is in connecting households and markets.

Originality/value

Identifying the impacts of policy and institutional settings associated with forage‐livestock systems is crucial if improvements are to be made and as these systems become more widespread in Western China.

Details

China Agricultural Economic Review, vol. 1 no. 4
Type: Research Article
ISSN: 1756-137X

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Article
Publication date: 15 September 2023

Zengli Wang, Qingyang Wang, Muming Hao, Xiaoying Li and Kewei Liu

The purpose of this study is to investigate the sealing performance of S-CO2 dry gas seals (DGSs) by considering the effects of pressure-induced deformation, thermal deformation…

154

Abstract

Purpose

The purpose of this study is to investigate the sealing performance of S-CO2 dry gas seals (DGSs) by considering the effects of pressure-induced deformation, thermal deformation and coupling deformation.

Design/methodology/approach

A hydrodynamic lubrication flow model of S-CO2 DGS was established, and the model was solved using the finite difference and finite element methods. The pressure-induced deformation and thermal deformation of the sealing ring, as well as the sealing performance under the effects of pressure-induced deformation, thermal deformation and coupling deformation, were obtained.

Findings

The deformation of the sealing ring is mainly thermal deformation. The influence of pressure-induced deformation on leakage and gas film stiffness is greater than that of thermal deformation and coupling deformation. However, thermal deformation has a greater impact on friction torque and minimum film thickness than pressure-induced deformation and coupling deformation. The influence of deformations on sealing performance is important.

Originality/value

The sealing performance of S-CO2 DGSs was analyzed considering the effect of pressure-induced deformation, thermal deformation and coupling deformation, which can provide a theoretical basis for S-CO2 DGS optimization design.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-04-2023-0120/

Details

Industrial Lubrication and Tribology, vol. 75 no. 8
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 6 November 2023

Xin Meng, Qingyang Ren, Songqiang Xiao, Bin Chen and Hongfei Li

The purpose of this paper is to simulate the tension process of tension-type anchor cable and to explore the mechanical characteristics and tension-torsion coupling effect of…

61

Abstract

Purpose

The purpose of this paper is to simulate the tension process of tension-type anchor cable and to explore the mechanical characteristics and tension-torsion coupling effect of anchor cable subjected to tension.

Design/methodology/approach

ABAQUS numerical software is applied to construct the numerical models of tension-type anchor cables with different diameters. Through explicit contact, the characteristics of contact between grouting body-anchor cable and grouting body-rock mass are determined. Confining pressure is applied to the model through surface pressure, and drawing force is applied to the model by displacement loading so as to simulate the tension process of the anchor cable.

Findings

The results show that the stress is transmitted in both axial and radial directions in the anchorage section and distributed in a cone. The shear stress in the grouting body is unevenly distributed, and its peak value increases with the rise in confining pressure and anchor cable diameter. The stress characteristics of torque and axial force are basically consistent and evenly distributed in the free section; they gradually decrease in the anchorage section. Due to the tension-torsion coupling effect, the internal stress characteristics of the anchor cable structure vary. On average, the anchorage performance of each anchor cable model is improved by 6.19%.

Originality/value

The proposed method of numerical modelling is effective in addressing the interface contact between the anchor cable and the grouting body and in solving the problem with convergence of calculation. Compared with the indoor test, this method is more suited to collecting the internal mechanical data of the anchor body.

Details

Engineering Computations, vol. 40 no. 9/10
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 14 February 2025

Yanan Wei, Heyun Bao, Qingyang Li and Zezong Huang

Thermal failure and incomplete separation often occur in aviation wet friction clutches. The purpose of this study is to improve the performance and reliability of the clutch…

4

Abstract

Purpose

Thermal failure and incomplete separation often occur in aviation wet friction clutches. The purpose of this study is to improve the performance and reliability of the clutch, considering the influence of lubricating oil, in this paper, the finite element method is used to simulate the friction pair of clutch with separation spring.

Design/methodology/approach

Considering the influence of lubricating oil, based on computational fluid dynamics principle and applying multiple reference frame method, simulation is carried out in FLUENT software to study the distribution of flow field and temperature field of clutch friction pair and separation spring under the condition of maximum relative speed of 3000 r/min.

Findings

The middle friction pair has more oil distribution, while the two sides have less oil distribution, and the highest oil volume exceeds that of the lowest by a factor of 3.49. Under the influence of lubricating oil distribution and component heat conduction, the temperature of the separation spring on both sides is higher than that of the separation spring in the middle. The axial temperature distribution law of the friction pair is the same as that of the separation spring, and the difference of the highest temperature between the friction pair is 136.41°C.

Social implications

The heat generation of the clutch is studied to improve the performance of the clutch and ensure the safety of the helicopter.

Originality/value

By analyzing the temperature and flow field of a wet friction clutch with a separation spring, engineers can help provide the service life and reliability of the clutch friction pair.

Details

Industrial Lubrication and Tribology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 8 June 2015

Haomiao Zhang

The purpose of this paper is to assess China’s urban social assistance policy, mainly by examining the findings of in-depth interviews with urban Dibao recipients in Chengdu about…

681

Abstract

Purpose

The purpose of this paper is to assess China’s urban social assistance policy, mainly by examining the findings of in-depth interviews with urban Dibao recipients in Chengdu about their experiences with social assistance, and by comparing what the social assistance offers with the urban poor households’ actual needs and vulnerabilities.

Design/methodology/approach

In this study, the author interviewed 15 people from urban Dibao Households in Wuhou District and Qingyang District of Chengdu, China. The interviews were conducted from April to August in 2013, usually in their homes. The small sample naturally limits generalizations, however it can point to directions for future research.

Findings

It is found out that urban Dibao which is the core of social assistance policy provides insufficient cash support and other special assistance programs are more of tokenistic which do not offer much help. Besides, due to lack of psychological aid, many recipients show negative and pessimistic attitudes toward life.

Originality/value

Regarding the assessment of social assistance policy in China, the international literature has shown little interest. Several Chinese scholars have analyzed urban social assistance system, but they tend to examine or assess from the perspective of policy makers and focus on making policy suggestions. Thus, there is not much information about whether what the social assistance offers could meet the urban poor households’ actual needs and vulnerabilities. An interesting endeavor would be to explore and assess the urban social assistance policy from the perspective of the recipients, and this is exactly what this paper aims to do.

Details

International Journal of Sociology and Social Policy, vol. 35 no. 5/6
Type: Research Article
ISSN: 0144-333X

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Article
Publication date: 11 December 2019

Scott Eacott and Amanda Freeborn

School consolidation reforms are underway in regional New South Wales (NSW), Australia. The purpose of this paper is to establish an evidence base of research literature on school…

516

Abstract

Purpose

School consolidation reforms are underway in regional New South Wales (NSW), Australia. The purpose of this paper is to establish an evidence base of research literature on school consolidation in regional, rural and remote locations.

Design/methodology/approach

A scoping study of empirical literature on school consolidation, with a particular focus on regional, rural and remote education, since the year 2000 was undertaken. A corpus of 35 papers were identified and subjected to analysis based on: year of publication, country of origin, unit of analysis, data sources, timeframe and theoretical model.

Findings

There remains a limited evidence base for the success of school consolidation reforms for turning around student outcomes. In addition, a number of social implications are experienced by communities losing their local school. These issues are amplified in regional, rural and remote locations.

Practical implications

School consolidation reforms are used by governments/systems wanting to reduce costs and address issues of student disengagement and under-achievement. Despite a lengthy history internationally, there is at best mixed evidence regarding these reforms. With a consider disparity gap between urban and regional, rural and remote school outcomes, robust evidence on the success of reforms has major policy implications for government, systems, educators and communities.

Originality/value

With reforms already underway in NSW (and elsewhere), the need for a rigorous and robust evidence base, such as this scoping study, is timely and significant.

Details

International Journal of Educational Management, vol. 34 no. 3
Type: Research Article
ISSN: 0951-354X

Keywords

Available. Open Access. Open Access
Article
Publication date: 14 May 2024

Rui Jia, Zhimin Shuai, Tong Guo, Qian Lu, Xuesong He and Chunlin Hua

This study aims to analyze the influence of farmers’ degree of participation in collective action on their adoption decisions and waiting time regarding soil and water…

715

Abstract

Purpose

This study aims to analyze the influence of farmers’ degree of participation in collective action on their adoption decisions and waiting time regarding soil and water conservation (SWC) measures.

Design/methodology/approach

The Probit model and Generalized Propensity Score Match method are used to assess the effect of the degree of participation in collective action on farmers’ adoption decisions and waiting time for implementing SWC measures.

Findings

The findings reveal that farmers’ engagement in collective action positively influences the decision-making process regarding terrace construction, water-saving irrigation and afforestation measures. However, it does not significantly impact the decision-making process for plastic film and ridge-furrow tillage practices. Notably, collective action has the strongest influence on farmers’ adoption decisions regarding water-saving irrigation technology, with a relatively smaller influence on the adoption of afforestation and terrace measures. Moreover, the results suggest that participating in collective action effectively reduces the waiting time for terrace construction and expedites the adoption of afforestation and water-saving irrigation technology. Specifically, collective action has a significantly negative effect on the waiting time for terrace construction, followed by water-saving irrigation technology and afforestation measures.

Practical implications

The results of this study underscore the significance of fostering mutual assistance and cooperation mechanisms among farmers, as they can pave the way for raising funds and labor, cultivating elite farmers, attracting skilled labor to rural areas, enhancing the adoption rate and expediting the implementation of terraces, water-saving irrigation technology and afforestation measures.

Originality/value

Drawing on an evaluation of farmers’ degree of participation in collective action, this paper investigates the effect of participation on their SWC adoption decisions and waiting times, thereby offering theoretical and practical insights into soil erosion control in the Loess Plateau.

Details

International Journal of Climate Change Strategies and Management, vol. 16 no. 2
Type: Research Article
ISSN: 1756-8692

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Book part
Publication date: 26 September 2022

Jing Liu

Since the early 2000s, China has been actively promoting school collaboration to narrow down educational gaps between schools to achieve inclusive and quality education for all…

Abstract

Since the early 2000s, China has been actively promoting school collaboration to narrow down educational gaps between schools to achieve inclusive and quality education for all. Among the reforms, building education groups has become one of the most widely adopted approaches for school improvement. This chapter aims at visualizing a hybrid model of school collaboration formulated by both hierarchist and egalitarian approaches in the Chengdu City of China. It starts with policy review on the construction of education groups for education improvement in China to interpret how social cohesion and regulation are constructed at policy level to promote school collaboration. Through data collected from education groups in District A of Chengdu, it then provides an analysis of the practice of improving education quality through promoting education groups among public schools in this province. The study reveals top-down policy initiatives, bottom-up school autonomy, and a shared responsibility for constructing quality education for all are key factors which enabled education groups to contribute to school improvement. The research also reveals how a lack of policy coordination and limited shared value and trust within education groups have become barriers to this reform. It concludes by discussing possible solutions for further promoting a sustainable school collaboration based on experiences of some ongoing practices at school level.

Details

School-to-School Collaboration: Learning Across International Contexts
Type: Book
ISBN: 978-1-80043-669-5

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Article
Publication date: 1 September 2016

Xiaohui Yu, Fei Wang and Lina Wang

City wall is an important symbol of ancient Chinese cities with unique geographical and cultural characteristics. Thus, the preservation of this historic landmark is considered…

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Abstract

City wall is an important symbol of ancient Chinese cities with unique geographical and cultural characteristics. Thus, the preservation of this historic landmark is considered significantly important. However, numerous residential construction activities and changes in ecological environment have destructed a great portion of the city walls in recent years. This study looks into the preservation of the ancient city walls from the systematic perspective and in line with the actual characteristics of Longdong Region to provide guideline measures for the protection and restoration of such landmark. Cognition and preservation are adopted extensively to investigate the specific situation of and the factors that influence the ancient city walls in this region. Preservation strategies for the city walls, including the “Axis-Point” system, planning control, and authenticity readability, are presented. The ancient city walls in Longdong Region can be preserved by protecting the entire region, the city, and the main wall body. The systematic method and preservation strategies at the “macro perspective,” “medium perspective” and “micro perspective” levels can solve the preservation problems of the ancient city walls in Longdong Region effectively.

Details

Open House International, vol. 41 no. 3
Type: Research Article
ISSN: 0168-2601

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