Yajing Hu, Botong Li, Xinhui Si, Jing Zhu and Linyu Meng
Atherosclerosis tends to occur in the distinctive carotid sinus, leading to vascular stenosis and then causing death. The purpose of this paper is to investigate the effect of…
Abstract
Purpose
Atherosclerosis tends to occur in the distinctive carotid sinus, leading to vascular stenosis and then causing death. The purpose of this paper is to investigate the effect of sinus sizes, positions and hematocrit on blood flow dynamics and heat transfer by different numerical approaches.
Design/methodology/approach
The fluid flow and heat transfer in the carotid artery with three different sinus sizes, three different sinus locations and four different hematocrits are studied by both computational fluid dynamics (CFD) and fluid-structure interaction (FSI) methods. An ideal geometric model and temperature-dependent non-Newtonian viscosity are adopted, while the wall heat flux concerning convection, radiation and evaporation is used.
Findings
With increasing sinus size, the average velocity and temperature of the blood fluid decrease, and the area of time average wall shear stress (TAWSS)with small values decreases. As the distances between sinuses and bifurcation points increase, the average temperature and the maximum TAWSS decrease. Atherosclerosis is more likely to develop when the sinuses are enlarged, when the sinuses are far from bifurcation points, or when the hematocrit is relatively large or small. The probability of thrombosis forming and developing becomes larger when the sinus becomes larger and the hematocrit is small enough. The movement of the arterial wall obviously reduces the velocity of blood flow, blood temperature and WSS. This study also suggests that the elastic role of arterial walls cannot be ignored.
Originality/value
The hemodynamics of the internal carotid artery sinus in a carotid artery with a bifurcation structure have been investigated thoroughly, on which the impacts of many factors have been considered, including the non-Newtonian behavior of blood and empirical boundary conditions. The results when the FSI is considered and absent are compared.
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Yun Zhang, Xiaogang Chen, Xinhui Liu and Nan Zhu
With the development of information technology, there is a growing trend for internet enterprises in China to launch internet-only banks. This paper aims to explore how the brand…
Abstract
Purpose
With the development of information technology, there is a growing trend for internet enterprises in China to launch internet-only banks. This paper aims to explore how the brand trust in an internet enterprise is transferred to the initial trust in its affiliated internet-only bank and how such transfer affects adoption behavior of potential internet-only banking users.
Design/methodology/approach
Data were obtained from online questionnaires via a well-known Chinese survey website and a popular Chinese social platform, which yielded 486 usable responses for the analysis. Partial least squares was used for testing hypotheses.
Findings
The results show that brand trust in the internet enterprise increases initial trust in its affiliated internet-only bank. This, in turn, enhances the adoption of internet-only banking. More importantly, these results show that brand trust in the internet enterprise transfers to initial trust in internet-only banking through performance expectancy and perceived risk. Further, the need for interaction moderates the relationship between brand trust and performance expectancy as well as the relationship between brand trust and perceived risk.
Originality/value
This study provides new insights into the mechanism by which trust is transferred between two affiliated business entities. The results of the study suggest several useful managerial implications for managing the internet-only banks.
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Jawad Raza, Fateh Mebarek-Oudina and A.J. Chamkha
The purpose of this paper is to examine the combined effects of thermal radiation and magnetic field of molybdenum disulfide nanofluid in a channel with changing walls. Water is…
Abstract
Purpose
The purpose of this paper is to examine the combined effects of thermal radiation and magnetic field of molybdenum disulfide nanofluid in a channel with changing walls. Water is considered as a Newtonian fluid and treated as a base fluid and MoS2 as nanoparticles with different shapes (spherical, cylindrical and laminar). The main structures of partial differential equations are taken in the form of continuity, momentum and energy equations.
Design/methodology/approach
The governing partial differential equations are converted into a set of nonlinear ordinary differential equations by applying a suitable similarity transformation and then solved numerically via a three-stage Lobatto III-A formula.
Findings
All obtained unknown functions are discussed in detail after plotting the numerical results against different arising physical parameters. The validations of numerical results have been taken into account with other works reported in literature and are found to be in an excellent agreement. The study reveals that the Nusselt number increases by increasing the solid volume fraction for different shapes of nanoparticles, and an increase in the values of wall expansion ratio α increases the velocity profile f′(η) from lower wall to the center of the channel and decreases afterwards.
Originality/value
In this paper, a numerical method was utilized to investigate the influence of molybdenum disulfide (MoS2) nanoparticles shapes on MHD flow of nanofluid in a channel. The validity of the literature review cited above ensures that the current study has never been reported before and it is quite new; therefore, in case of validity of the results, a three-stage Lobattoo III-A formula is implemented in Matlab 15 by built in routine “bvp4c,” and it is found to be in an excellent agreement with the literature published before.
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Lijie Ma, Xinhui Mao, Chenrui Li, Yu Zhang, Fengnan Li, Minghua Pang and Qigao Feng
The purpose of this study is to reveal the friction reduction performance and mechanism of granular flow lubrication during the milling of difficult-to-machining materials and…
Abstract
Purpose
The purpose of this study is to reveal the friction reduction performance and mechanism of granular flow lubrication during the milling of difficult-to-machining materials and provide a high-performance lubrication method for the precision cutting of nickel-based alloys.
Design/methodology/approach
The milling tests for Inconel 718 superalloy under dry cutting, flood lubrication and granular flow lubrication were carried out, and the milling force and machined surface quality were used to evaluate their friction reduction effect. Furthermore, based on the energy dispersive spectrometer (EDS) spectrums and the topographical features of machined surface, the lubrication mechanism of different granular mediums was explored during granular flow lubrication.
Findings
Compared with flood lubrication, the granular flow lubrication had a significant force reduction effect, and the maximum milling force was reduced by about 30%. At the same time, the granular flow lubrication was more conducive to reducing the tool trace size, repressing surface damage and thus achieving better surface quality. The soft particles had better friction reduction performance than the hard particles with the same particle size, and the friction reduction performance of nanoscale hard particles was superior to that of microscale hard particles. The friction reduction mechanism of MoS2 and WS2 soft particles is the mending effect and adsorption film effect, whereas that of SiO2 and Al2O3 hard particles is mainly manifested as the rolling and polishing effect.
Originality/value
Granular flow lubrication was applied in the precision milling of Inconel 718 superalloy, and a comparative study was conducted on the friction reduction performance of soft particles (MoS2, WS2) and hard particles (SiO2, Al2O3). Based on the EDS spectrums and topographical features of machined surface, the friction reduction mechanism of soft and hard particles was explored.
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Naveed Ahmed, Umar Khan and Syed Tauseef Mohyud-din
The aim of this manuscript is to study the flow of a nanofluid through a porous channel under the influence of a transverse magnetic field. Permeability of the walls is…
Abstract
Purpose
The aim of this manuscript is to study the flow of a nanofluid through a porous channel under the influence of a transverse magnetic field. Permeability of the walls is considered to be different, which results in an asymmetric nature of the flow. The height of the channel is variable, and it dilates or squeezes at a uniform rate.
Design/methodology/approach
A numerical solution (Runge–Kutta–Fehlberg) has been obtained after reducing the governing equations to a system of nonlinear ordinary differential equations using some suitable similarity transforms, both in time and space.
Findings
An increase in absolute values of the permeability parameter results in an enhanced mass transfer rate at both the walls, while the rate of heat transfer also increases at the lower wall. Few graphs are also dedicated to see the behavior of Nusselt and Sherwood numbers following the variations in flow parameters.
Originality/value
A pictorial description of the flow and effects of emerging parameters on the temperature and nanoparticle concentration profiles is presented to analyze the flow behavior. It is established that the asymmetry of the channel affects the flow quite significantly.
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Keywords
In mid-2013, the Lee family, which owned the Hong Kong based food and health product giant Lee Kum Kee (LKK), struggled with how best to increase involvement of the fifth…
Abstract
In mid-2013, the Lee family, which owned the Hong Kong based food and health product giant Lee Kum Kee (LKK), struggled with how best to increase involvement of the fifth generation (G5), the children of the company's current fourth-generation (G4) senior executives and governance leaders. Only two of the fourteen G5 members had joined the company, and few had expressed interest in further involvement, including in the multiple learning and development programs the business offered, such as a mentoring program. Many of the G5 cousins had expressed little interest in business careers in general, and none of them currently was serving as an LKK intern. G4 members observed that their children were busy with family obligations, hobbies, and emerging careers outside the business. G5's lack of interest in business and governance roles was part of a growing pattern of low family engagement in general, exhibited by the cancellation of recent family retreats (once an annual tradition) because of apathy and some underlying conflict. A history of splits among past generations of the Lee family regarding business leadership made the engagement issue even more meaningful and critical.
Students will consider the challenge from the point of view of G4 family members David Lee, chairman of the family's Family Office, and his sister, Elizabeth Mok, who ran the Family Learning and Development Center. They and their three siblings saw engaging the next generation as a top priority, one related to key concepts including family-business continuity, generational engagement and empowerment, succession, emotional ownership, and intrinsic/extrinsic motivation.
Details
![Kellogg School of Management](/insight/static/img/kellogg-school-of-management-logo.png)
Keywords
This study aims to reveal the influence of milling process parameters on the surface roughness and morphology of superalloy GH4145.The groove milling mechanism and surface quality…
Abstract
Purpose
This study aims to reveal the influence of milling process parameters on the surface roughness and morphology of superalloy GH4145.The groove milling mechanism and surface quality influence factors of superalloy GH4145 were studied experimentally.
Design/methodology/approach
This paper provides investigations on three-dimensional finite element model (FEM) and simulation of milling process for GH4145.The milling experiment uses Taguchi L16 experimental design and single factor experimental design. The surface morphology of the workpiece was observed by scanning electron microscopy, and the influence mechanism of milling parameters on surface quality is expounded.
Findings
The results show that the cutting force increases by 133% with the increase in milling depth. The measured minimum surface roughness is 0.035 µm. With the change in milling depth, the surface roughness increases by 249%. With the change in cutting speed, the surface roughness increased by 54.8%. As the feed rate increases, the surface roughness increases by a maximum of 91.1%. The milling experiment verifies that the error between the predicted surface roughness and the actual value is less than 8%.
Originality/value
The milling experiment uses a Taguchi L16 experimental design and a single-factor experimental design. Mathematical models can be used in research as a contribution to current research. In addition, the milling cutter can be changed to further test this experiment. Reveal the influence of milling process parameters on the surface roughness and morphology of superalloy GH4145.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2024-0080/