Yanzhong Wang, Chao Guo, Yuan Li and Guoxing Li
This study aims to establish a friction coefficient model relative to the rotation speed of a wet clutch engagement, which can predict friction coefficient under different stages…
Abstract
Purpose
This study aims to establish a friction coefficient model relative to the rotation speed of a wet clutch engagement, which can predict friction coefficient under different stages of slipping velocity and different load pressures. In particular, the model has been improved by accounting the speed effect for the perdition of wet friction-element boundary friction, which is significant for understanding the friction mechanisms and for supporting the development of more efficient and related products.
Design/methodology/approach
This research investigated the mechanism of wet friction in a wet clutch engagement. A mixed friction model is established based on the asperity model and Newton’s law of viscosity. To obtain a friction coefficient computed by the model, the normal load shared by both asperities and lubrication fluid needs to be determined. Therefore, rough surface contact mechanism is analysed; a surface topography model is established; and surface parameters are obtained by means of surface topography measurement and reconstruction. Finally, verification of the mixed friction model is achieved.
Findings
Friction will be generated by both the asperity contact and the lubrication film shear relative to the rotation speed. And, the higher the relative speed, the larger the shearing power of lubrication film. It is caused by decrease in contact area of asperity. Surface morphology of a sintered bronze friction disk was obtained by a Laser-Micro-Test. The predicted results by the established model show that the total friction coefficient slightly reduced and then increased suddenly with speed. The surface topography model is responsible for the nonlinear behaviour of the asperity friction. Results of the simulation model are in agreement with those of the wet clutch engagement experiments.
Originality/value
This research is original and it is supported by the national defence project. The wet friction element which is applied on tracked vehicles is analysed for the first time. Through the model, the trend of the friction coefficient can be more accurately predicted. The problem of the wet friction plate modelling difficult is solved by using the mixed friction model.
Details
Keywords
Guangyuan Xing, Yi Li, Haixu Bao, Guoxing Zhang and Zhenguo Li
Public crisis often generates new knowledge that should be incorporated into a government’s macro-control to ensure the relief supply. From the perspective of public crisis…
Abstract
Purpose
Public crisis often generates new knowledge that should be incorporated into a government’s macro-control to ensure the relief supply. From the perspective of public crisis knowledge management, the Chinese system of Government relief supplies can be considered as a special case of the knowledge system. This paper aims to investigate the supply and production mechanism of relief goods and explore the advantages of the Chinese system when a sudden public crisis occurs.
Design/methodology/approach
Under the Chinese system, the authors construct a relief supply chain model consisting of the Chinese Government, one manufacturer and one supplier, where the supplier has no capital constraints. Given the demand for relief goods, the government purchases from the manufacturer with a guide price. Then, the manufacturer decides on its order quantity and offers a wholesale price to the supplier. The supplier has a random capacity and decides on the level of knowledge acquisition to improve its capacity.
Findings
The authors first obtain the analytical solution for the manufacturer to motivate a high level of knowledge acquisition from the supplier. Specifically, the manufacturer’s optimal order quantity is equal to the demand and the optimal wholesale price has a cost-plus form that reimburses the supplier for its production cost and knowledge-acquisition cost. Next, the authors derive the optimal guide price for the government, which should be set to subsidize the manufacturer with a proportion of the sourcing cost. Finally, the authors compare the Chinese system with the market mechanism where the supplier has capital constraints and confirm that the Chinese system is more beneficial to both the manufacturer and the government.
Originality/value
Quantitative research on the Chinese system of Government relief supplies is difficult to be conducted. This paper provides feasible and practical methods to quantify the benefits of the Chinese system. The results reveal that the Chinese system is an effective mechanism of public crisis knowledge management, which can be helpful to the government’s policy-making in practice.
Details
Keywords
Xiaodong Li, Shengliang Zhang, Chuang Wang and Xinshuai Guo
Due to interactive fluctuations during service encounters, fuzzy requests frequently occur from either frontline employees or customers. While such requests from customers have…
Abstract
Purpose
Due to interactive fluctuations during service encounters, fuzzy requests frequently occur from either frontline employees or customers. While such requests from customers have been drawn wide attention, there exists a lack of research on frontline employees’ fuzzy requests and possible outcomes (e.g. compliance or refusal). The purpose of this study is thus to identify the underlying mechanism and enacting variables that influence customers’ compliance behaviour (i.e. positive outcome) to fuzzy requests.
Design/methodology/approach
Data were collected from a sample of ten express service companies in southeast China. The proposed model was empirically tested among 309 customers and further analysed through structural equation modelling.
Findings
The results indicated that expected technical quality, perceived reasonableness and perceived convenience are positively associated with compliance behaviour, whereas the effects of inertia and negative emotional response on compliance behaviour are significantly negative. The findings also demonstrated that negative emotional response partially mediates the impacts of expected technical quality, perceived reasonableness and inertia on compliance behaviour.
Originality/value
This study investigates an under-researched phenomenon, namely, frontline employees’ fuzzy requests in the service context. The underlying mechanism of customers’ compliance behaviours to fuzzy requests is articulated through an integration of three beliefs with emotional response. As an early exploration of employees’ fuzzy requests, this study provides important theoretical and managerial implications.
Details
Keywords
Tinggui Wang, Guoxing Cai, Letao Zhang, Li Ma, Erlei Yu and Wumanjiang Eli
– The Friedel-Crafts alkylation of biphenyl with 1-octene was completed using methanesulfonic acid (MSA) as catalyst.
Abstract
Purpose
The Friedel-Crafts alkylation of biphenyl with 1-octene was completed using methanesulfonic acid (MSA) as catalyst.
Design/methodology/approach
Single factor experiments were carried out to investigate the influence of the molar ratio of biphenyl to 1-octene, the amount of MSA, reaction temperature and reaction time on the olefins conversion and the yield of product to obtain the optimal reaction conditions. Under the optimum conditions, a lubricating base stock was synthesized, and its physical, chemical and electrical properties were determined.
Findings
The experimental results showed that after a 5 h reaction time at 353 K, the olefins conversion of 94.9 per cent and the yield of product of 69.3 per cent were obtained with a molar ratio of biphenyl to 1-octene of 1.2 and a molar ratio of MSA to 1-octene of 1. Under the optimum conditions, a lubricating base stock was synthesized, and its physical, chemical and electrical properties were determined. The results suggested that the synthetic base stock could be used as refrigeration oil.
Originality/value
In this manuscript, biphenyl was alkylated with 1-octene using MSA as the catalyst and 2.6-di-t-butylphenol as polymerization inhibitor. Compared with traditional catalysts, it has so many advantages as low tendency to oxidize organic compounds, low toxicity and less corrosion. In addition, it can be readily separated from the reaction mixture and can be reused. Moreover, MSA is an environmentally friendly material.
Details
Keywords
Leilei Shi, Xinshuai Guo, Andrea Fenu and Bing-Hong Wang
This paper applies a volume-price probability wave differential equation to propose a conceptual theory and has innovative behavioral interpretations of intraday dynamic market…
Abstract
Purpose
This paper applies a volume-price probability wave differential equation to propose a conceptual theory and has innovative behavioral interpretations of intraday dynamic market equilibrium price, in which traders' momentum, reversal and interactive behaviors play roles.
Design/methodology/approach
The authors select intraday cumulative trading volume distribution over price as revealed preferences. An equilibrium price is a price at which the corresponding cumulative trading volume achieves the maximum value. Based on the existence of the equilibrium in social finance, the authors propose a testable interacting traders' preference hypothesis without imposing the invariance criterion of rational choices. Interactively coherent preferences signify the choices subject to interactive invariance over price.
Findings
The authors find that interactive trading choices generate a constant frequency over price and intraday dynamic market equilibrium in a tug-of-war between momentum and reversal traders. The authors explain the market equilibrium through interactive, momentum and reversal traders. The intelligent interactive trading preferences are coherent and account for local dynamic market equilibrium, holistic dynamic market disequilibrium and the nonlinear and non-monotone V-shaped probability of selling over profit (BH curves).
Research limitations/implications
The authors will understand investors' behaviors and dynamic markets through more empirical execution in the future, suggesting a unified theory available in social finance.
Practical implications
The authors can apply the subjects' intelligent behaviors to artificial intelligence (AI), deep learning and financial technology.
Social implications
Understanding the behavior of interacting individuals or units will help social risk management beyond the frontiers of the financial market, such as governance in an organization, social violence in a country and COVID-19 pandemics worldwide.
Originality/value
It uncovers subjects' intelligent interactively trading behaviors.
Details
Keywords
Maher Taha El-Nimr, Ali Mohamed Basha, Mohamed Mohamed Abo-Raya and Mohamed Hamed Zakaria
To predict the real behavior of the full-scale model using a scale model, optimized simulation should be achieved. In reinforced concrete (RC) models, scaling can be substantially…
Abstract
Purpose
To predict the real behavior of the full-scale model using a scale model, optimized simulation should be achieved. In reinforced concrete (RC) models, scaling can be substantially more critical than in single-material models because of multiple reasons such as insufficient bonding strength between small-diameter steel bars and concrete, and excessive aggregate size. Overall, there is a shortfall of laboratory and field-testing studies on the behavior of secant pile walls under lateral and axial loads. Accordingly, the purpose of this study is to investigate the validity and the performance of the 1/10th scaled RC secant pile wall under the influence of different types of loading.
Design/methodology/approach
The structural performance of the examined models was evaluated using two types of tests: bending and axial compression. A self-compacting concrete mix was suggested, which provided the best concrete mix workability and appropriate compressive strength.
Findings
Under axial and bending loads, the failure modes were typical. Where the plain and reinforced concrete piles worked in tandem to support the load throughout the loading process, even when they failed. The experimental results were relatively consistent with some empirical equations for calculating the modulus of elasticity and critical buckling load. This confirmed the validity of the proposed model.
Originality/value
According to the analysis and verification of experimental tests, the proposed 1/10th scaled RC secant pile model can be used for future laboratory purposes, especially in the field of geotechnical engineering.
Details
Keywords
Aniruddh Nain, Deepika Jain and Ashish Trivedi
This paper aims to examine and compare extant literature on the application of multi-criteria decision-making (MCDM) techniques in humanitarian operations (HOs) and humanitarian…
Abstract
Purpose
This paper aims to examine and compare extant literature on the application of multi-criteria decision-making (MCDM) techniques in humanitarian operations (HOs) and humanitarian supply chains (HSCs). It identifies the status of existing research in the field and suggests a roadmap for academicians to undertake further research in HOs and HSCs using MCDM techniques.
Design/methodology/approach
The paper systematically reviews the research on MCDM applications in HO and HSC domains from 2011 to 2022, as the field gained traction post-2004 Indian Ocean Tsunami phenomena. In the first step, an exhaustive search for journal articles is conducted using 48 keyword searches. To ensure quality, only those articles published in journals featuring in the first quartile of the Scimago Journal Ranking were selected. A total of 103 peer-reviewed articles were selected for the review and then segregated into different categories for analysis.
Findings
The paper highlights insufficient high-quality research in HOs that utilizes MCDM methods. It proposes a roadmap for scholars to enhance the research outcomes by advocating adopting mixed methods. The analysis of various studies revealed a notable absence of contextual reference. A contextual mind map specific to HOs has been developed to assist future research endeavors. This resource can guide researchers in determining the appropriate contextual framework for their studies.
Practical implications
This paper will help practitioners understand the research carried out in the field. The aspiring researchers will identify the gap in the extant research and work on future research directions.
Originality/value
To the best of the authors’ knowledge, this is the first literature review on applying MCDM in HOs and HSCs. It summarises the current status and proposes future research directions.