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1 – 10 of over 16000F. Guo, J. Lee and K.N. Subramanian
In an attempt to improve service life of lead‐free Sn‐based electronic solder joints, compatible reinforcements were introduced by in‐situ and mechanical mixing methods. The…
Abstract
In an attempt to improve service life of lead‐free Sn‐based electronic solder joints, compatible reinforcements were introduced by in‐situ and mechanical mixing methods. The reinforcements affect the steady‐state creep rate and the strain for the onset of tertiary creep of the solder joints. However, neither of these parameters, when considered alone, can be used for evaluating the reliability of solder joints. The Larson‐Miller parameter, and a new parameter proposed in the paper, can incorporate test parameters to arrive at a reliability prediction methodology. The role of these reinforcements in homogenising creep strain within the joint is analysed. The observed creep behaviour of these composite solders is discussed on the basis of interfacial bonding strength between the reinforcement and the solder matrix.
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Zhanchao Wang, Fei Guo, Ying Liu, Xiangfeng Liu and Yuming Wang
This aim of this paper has been to investigate the squeeze effect of a water-lubricated tilting-pad thrust bearing during start-up and shut-down periods.
Abstract
Purpose
This aim of this paper has been to investigate the squeeze effect of a water-lubricated tilting-pad thrust bearing during start-up and shut-down periods.
Design/methodology/approach
In this paper a numerical model with a squeeze and slippage effect was adopted to analyse the asymmetry characteristic of a tilting-pad thrust bearing during start-up and shut-down periods. A test rig was built to verify numerical results, which were a combined measurement method in which acceleration sensor and torque sensor were used simultaneously to determine the angle change of the thrust pad.
Findings
It was found that as the velocity gradient increased, the difference of the minimum dimensionless film Hmin could be ignored in the start-up process. But in the shut-down process, as the velocity gradient increased, the value of Hmin also increased, which showed that there was an asymmetry characteristic of the tilting bearing in two processes. This phenomenon was verified by measuring the friction torque curve in the test.
Originality/value
The results of the studies demonstrated that the velocity gradient could be designed to reduce the friction of the thrust bearing, which would be beneficial to the working life of the tilting-pad thrust bearing.
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Abstract
Purpose
The purpose of this paper is to improve the anti‐sedimentation of the acrylic resin containing long afterglow phosphors (SrMgAl4O8:Eu2+, Dy3+).
Design/methodology/approach
The phosphors were first modified by the vinylsilane coupling agent MPS (3‐(methacryloxypropyl)‐trimethoxysilane). Then, the acrylic resin containing modified phosphors was synthesised by in situ polymerisation. Meanwhile, the compared blend sample was prepared by pure acylic resin with no modified phosphors in the same content. When the two resins were coated on glass, the films were characterised by ATR‐FTIR, SEM and TGA. The sedimentation performances of liquid resins were also observed.
Findings
Results showed that anti‐sedimentation of acrylic resin with phosphors by in situ polymerisation was enhanced greatly, because the phosphors have been connected with the macromolecule chain, and dispersed homogeneously with no aggregation, so preventing its sedimentation.
Research limitations/implications
Researchers are encouraged to test the proposed method and enhance the anti‐sedimentation further.
Practical implications
This method provides an idea to solve the problem of anti‐sedimentation in luminescent paint containing long afterglow phosphors in practical production and application.
Originality/value
This paper introduced the in situ polymerisation to enhance the anti‐sedimentation of acrylic resin containing long afterglow phosphors and it can be applied also to other inorganic powders.
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Abstract
Purpose
The purpose of this paper is to report on a study which aims to improve the compatibility of the long afterglow phosphors SrMgAl4O8:Eu2+, Dy3+with organic matrix, including its water resistance.
Design/methodology/approach
The phosphors were modified by the lauric acid‐based Al‐Zr coupling agent (CA). Then, they were characterised by attenuated total reflection fourier transform infrared (ATR‐FTIR), pH and electric conductivity in water, scanning electron microscope (SEM), contact angle and fluorescence decay curves before and after modification.
Findings
The pH and electric conductivity displayed the improved water resistance, as the Al‐Zr CA addition increased, and the minimum contact angle with resin decreased from 68.3 to 40.3°C, which showed that the compatibility with organic matrix was enhanced significantly. The afterglow luminous properties were unimpaired.
Research limitations/implications
The researchers are encouraged to test the proposed method and enhance the compatibility further.
Practical implications
This method will extend the applications of phosphors in the paint, coatings, ink and plastics industry.
Originality/value
This paper introduces the lauric acid‐based Al‐Zr CA to modify the luminescent pigments of long afterglow phosphors; it can be also applied to other inorganic powders.
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Shikha Agnihotri, Rekha Mewafarosh and Shivani Malhan
Purpose: The prominence of quality education for building sustainable development is undeniable and is distinctly pointed out in 1 of the 14 sustainable development goals (SDGs)…
Abstract
Purpose: The prominence of quality education for building sustainable development is undeniable and is distinctly pointed out in 1 of the 14 sustainable development goals (SDGs). In the same context, this study intends to investigate the role of university commitment, perceived organisational prestige, student satisfaction, and perceived employability in enhancing sustainability in higher education.
Need of the Study: To evaluate how student satisfaction mediates the relationship between university commitment, perceived organisational prestige, and perceived employability with sustainable university institutes.
Methodology: An adapted questionnaire was used in this study to capture the perception of 458 management graduates selected through the purposive sampling method. Partial least squares structural equation modelling (PLS-SEM) technique was used to analyse the data with the help of Smart PLS software.
Findings: The results of this study show that student satisfaction is the strongest predictor of sustainable university institutes. University commitment was found to lead to student satisfaction significantly. Furthermore, student satisfaction wasn’t found to play the role of mediator in the proposed model.
Practical Implications: This study aims to fulfil theoretical, research, and management implications for students, higher education institutes (HEIs), and policymakers. HEIs are recommended to instil university commitment, perceived organisational prestige and student satisfaction via various practices and amendments in their curriculum. Students are recommended to enhance their perceived employability to achieve career sustainability.
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J.G. Lee, F. Guo, K.N. Subramanian and J.P. Lucas
The influence of the thermal reflow profile on the formation and resultant morphology of the intermetallic layer that developed at the Ni particle reinforcements within an…
Abstract
The influence of the thermal reflow profile on the formation and resultant morphology of the intermetallic layer that developed at the Ni particle reinforcements within an eutectic Sn‐Ag composite solder matrix was investigated. The composite solder was fabricated by mechanically dispersing 15 vol% Ni particles into eutectic Sn‐3.5Ag solder paste. Two distinct intermetallic compound (IMC) morphological microstructures were observed around the Ni reinforcements. IMC morphological microstructure apparently varied depending on the amount of heat input and differences in heating rates used in the reflow profile. A “sunflower” IMC morphology was typically noted when the total amount of heat input was small. However, with sufficient heat input, a faceted “blocky” IMC morphology was consistently achieved. Multiple‐reflow thermal profiling experiments were conducted to measure and compare the amount of heat input necessary to change the sunflower IMC morphology around Ni particle reinforcements to the blocky morphology.
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Yongqiang Sun, Yafei Feng, Xiao-Liang Shen and Xitong Guo
Prior researches on the adoption of mobile health services (MHS) concentrate on the subjective cognitive appraisals resulting in technology adoption, while ignoring how to shape…
Abstract
Purpose
Prior researches on the adoption of mobile health services (MHS) concentrate on the subjective cognitive appraisals resulting in technology adoption, while ignoring how to shape those cognitive appraisals by the objective message design strategies which are easier to operate in practice. Based on protection motivation theory (PMT), the current research aims to explore the antecedents of cognitive appraisals by focusing on message design strategies of fear appeal and coping appeal.
Design/methodology/approach
A two-stage scenario-based survey of 204 participants was conducted to collect data. The authors chose SPSS and covariance-based structural equation modeling (CB-SEM) approach with the software LISREL 8.8 to test our model.
Findings
The results show that the relationship between fear appeal and fear arousal is inverted U-shaped such that the degree of fear arousal is the greatest when the fear appeal is at a moderate level. Perceived usefulness for the message with negative framing is higher than that with positive framing. Furthermore, fear appeal and coping appeal have a significant interaction on the adoption of MHS at different stages.
Research limitations/implications
The sample data of this study come from a special health service of a special group in China, which limits the universality of our research results for other groups or health care services. Therefore, future researchers can validate the model in other research scenarios and sample populations.
Originality/value
This study shows how fear appeal and coping appeal work together to influence individuals' adoption intention. The authors’ findings expand the theoretical depth of PMT and fear theory, enriching the theoretical connotation of framing effect in mobile health technology adoption context, which add new insights to design more persuasive messages through fear appeal and coping appeal for researchers and MHS providers in mobile health communication or propaganda.
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Kaiyang Wang, Fangyu Guo, Ruijia Zhou and Liang Qian
In recent years, augmented reality (AR) has shown its potential to assist various construction activities. Its use commonly requires additional refinement to be integrated into…
Abstract
Purpose
In recent years, augmented reality (AR) has shown its potential to assist various construction activities. Its use commonly requires additional refinement to be integrated into the building information modeling (BIM) process. Nevertheless, few studies have investigated AR implementation in BIM-enabled projects because of numerous challenges related to its implementation. This study aims to investigate the implementation of AR in construction and identify the critical mechanisms for implementing BIM-AR successfully.
Design/methodology/approach
A mixed methodology was adopted for this study. First, this work presents a bibliometric analysis covering articles obtained from Scopus database published between 2000 and 2022. A sample size of 65 research papers pertinent to AR in construction was analyzed using VOSviewer software. Second, a participatory case study was conducted for a BIM-enabled project in China to gain insight into how BIM-AR implementation in construction is achieved.
Findings
The findings from the bibliometric analysis show an increasing interest in AR research within construction. The results indicate that AR research focuses on four clusters: real-time communication, project management, construction activities and education. Findings from the case study provide an empirical experience of AR application scenarios in a BIM-enabled project. Concomitantly, 15 critical success factors that influence BIM-AR implementation were finally identified and demonstrated.
Originality/value
This study provides a rich insight into the understanding and awareness of implementing AR. First, the findings are beneficial to construction practitioners and researchers because they provide a concentrated perspective of AR for emerging activities in the construction industry. Second, the results obtained from the case study could provide a useful guide for effectively implementing AR in a BIM-enabled construction project. Overall, this study may stimulate further research on AR-related studies in construction, such as BIM integration, factor analysis and construction education.
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Due to the cross-network effect, two-sided users communicate with each other, producing a coupling network. To study the spread of platform self-operation in two-sided users'…
Abstract
Purpose
Due to the cross-network effect, two-sided users communicate with each other, producing a coupling network. To study the spread of platform self-operation in two-sided users' marketing and purchasing tactics, this paper considers the differences in reputation acquired by platform-owned and third-party operating channels.
Design/methodology/approach
This study proposes a two-layer network with cross-network links: one layer represents the social network of consumers, while the other layer represents the competitive network of buyers. A closed system of differential equations, based on the binary dynamics of the stochastic network, is developed to study the trend and stability points of the platform self-operation dissemination. Then the overall benefits of platform are analyzed to unify the platform diffusion and pricing strategies.
Findings
The degree of difference in social influence and cross-network effects affect diffusion synergistically. Cross-network effects hinder diffusion when there is a significant difference of social influence between consumers and sellers but promote diffusion when there is little difference of social influence between consumers and sellers. Additionally, the network weights and reputation gap exhibit a nonlinear correlation with diffusion. For pricing strategy of the platform, it can achieve maximum profit when the pricing of self-operated goods and third-party-operated goods is equal.
Originality/value
This study considers the complex network architecture created by bilateral markets and the dynamic influence of group interactions on product. Additionally, this study takes reputation into account when considering the price and dissemination tactics of various operating channels, offering guidelines for platforms to control merchants and mediate disputes between various operating channels.
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