Cijun Shuai, Jingyu Zhuang, Shuping Peng and Xuejun Wen
The paper aims to fabricate an α-tricalcium phosphate (TCP) scaffold with an interconnected porous structure via selective laser sintering (SLS). To inhibit the phase…
Abstract
Purpose
The paper aims to fabricate an α-tricalcium phosphate (TCP) scaffold with an interconnected porous structure via selective laser sintering (SLS). To inhibit the phase transformation from β- to α-TCP in fabrication process of porous scaffolds, a small amount (1 weight per cent) of poly (L-lactic acid) (PLLA) is added into β-TCP powder to introduce the transient liquid phase.
Design/methodology/approach
The paper opted for the transient liquid phase of melting PLLA to decrease the sintering temperature in SLS. Meanwhile, the densification of β-TCP is enhanced with a combined effect of the capillary force caused by melting PLLA and the surface energy of β-TCP particles. Moreover, the PLLA will gradually decompose and completely disappear with laser irradiation.
Findings
The testing results show the addition of PLLA enables the scaffolds to achieve a higher β-TCP content of 77 ± 1.49 weight per cent compared with the scaffold sintered from β-TCP powder (60 ± 1.65 weight per cent), when the laser energy density is 0.4 J/mm2. The paper provides the mechanism of PLLA inhibition on the phase transformation from β- to α-TCP. And the optimum sintering parameters are obtained based on experimental results, which are used to prepare a TCP scaffold with an interconnected porous structure via SLS.
Research limitations/implications
This paper shows that the laser energy density is an important sintering parameter that can provide the means to control the micro-porous structure of the scaffold. If the laser energy density is too low, the densification is not enough. On the other hand, if the laser energy density is too high, the microcracks are observed which are attributed to the volume expansion during the phase transformation from β- to α-TCP. Therefore, the laser energy density must be optimized.
Originality/value
The paper provides a feasible method for fabricating TCP artificial bone scaffold with good biological and mechanical properties.
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Jianping Wang, Haifeng Ran, Peng Dai, Shuping Yan, Xingjia Yao, Fengtao Wang and Guizhong Zuo
Herringbone groove thrust bearings are typically used in high-speed, light-load applications, such as spindle motors for hard disk drives. In the past researches, the effect of…
Abstract
Purpose
Herringbone groove thrust bearings are typically used in high-speed, light-load applications, such as spindle motors for hard disk drives. In the past researches, the effect of shaft misalignment was little considered. This study aims to reveal effects of shaft misalignment on the microscopic flow regime in the water-lubricated herringbone groove thrust bearing.
Design/methodology/approach
The liquid film in a thrust herringbone groove bearing was investigated by computational fluid dynamics. The effects of micro-grooves on the flow field were carefully explored. Two-dimensional liquid films at four different sites were examined for obtaining the rich flow field properties.
Findings
The distributions of pressure, temperature and water vapor volume fraction were obtained, the micro hydrodynamic effects were formed by the herringbone grooves and the effects of the shaft misalignment on lubrication and sealing performance could be found.
Originality/value
The influence of misalignment on the herringbone groove thrust bearing performance was investigated in detail. The obtained results could give the reference guideline for the bearing design.
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Diellza Gashi Tresi and Katarina Katja Mihelič
Building on the work–home resources model, the purpose of this paper is to test the mediating role of employee self-efficacy in the relationship between job crafting and work–self…
Abstract
Purpose
Building on the work–home resources model, the purpose of this paper is to test the mediating role of employee self-efficacy in the relationship between job crafting and work–self facilitation. The paper further explores the moderating role of the quality of leader–member exchange (LMX).
Design/methodology/approach
A sample of 204 employees from a European country was used to test the proposed moderated mediation model. The analysis was performed using Hayes’ Process Macro.
Findings
The findings indicate that job crafting is positively associated with self-efficacy which, in turn, is positively associated with work–self facilitation. In other words, self-efficacy mediates the relationship between job crafting and work–self facilitation. Furthermore, LMX moderates the relationship between job crafting and self-efficacy.
Practical implications
The results of this study offer guidelines for human resource (HR) professionals interested in grasping how organisations can assist employees in experiencing work–self facilitation.
Originality/value
This study advances the existing literature by investigating the antecedents of work–self facilitation, which is an understudied variable in the work–family and HR literature, thereby responding to calls to include aspects of self in the discussion on different life domains in order to obtain an all-inclusive view of how employees function. Furthermore, it demonstrates how LMX and job crafting promote the fulfilment of an employee’s own personal interests and hobbies. Such information is relevant to HR practitioners as it might help them boost employees’ work performance.
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The purpose of this paper is to research the optimal portfolio proportion for the optimal investment model and the optimal consumption investment strategies for the optimal…
Abstract
Purpose
The purpose of this paper is to research the optimal portfolio proportion for the optimal investment model and the optimal consumption investment strategies for the optimal consumption investment model under compound‐jump processes.
Design/methodology/approach
Traditionally, the price of risky security or asset is often modeled as geometric Brownian motion. However, the analysis of stock price evolution reveals sudden and rare breaks logically accounted for by exogenous events on information. It is natural to model such behavior by means of a point process, or, more simply, by a Poisson process, which has jumps of constant size occurring at rare and unpredictable intervals. Assume that the price of risky security stock is modeled by a compound‐jump process, the renew process theory is chosen to solve the optimal investment model, the HJB equation is chosen for the optimal consumption investment model.
Findings
Derive the analytical optimal portfolio proportion for the reduction model of optimal investment. The optimal consumption investment strategies are given by some equations for the optimal consumption investment model.
Research limitations/implications
Accessibility and availability of data are the main limitations which model will be applied.
Practical implications
The results obtained in this paper could be used as a guide to actual portfolio management.
Originality/value
The new approach for the optimal portfolio model under compound‐jump processes. The paper is aimed at actual portfolio managers.
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Multi‐sensor data fusion (MSDF) is defined as the process of integrating information from multiple sources to produce the most specific and comprehensive unified data about an…
Abstract
Purpose
Multi‐sensor data fusion (MSDF) is defined as the process of integrating information from multiple sources to produce the most specific and comprehensive unified data about an entity, activity or event. Multi‐sensor object recognition is one of the important technologies of MSDF. It has been widely applied in the fields of navigation, aviation, artificial intelligence, pattern recognition, fuzzy control, robot, and so on. Hence, aimed at the type recognition problem in which the characteristic values of object types and observations of sensors are in the form of triangular fuzzy numbers, the purpose of this paper is to propose a new fusion method from the viewpoint of decision‐making theory.
Design/methodology/approach
This work, first divides the comprehensive transaction process of sensor signal into two phases. Then, aimed at the type recognition problem, the paper gives the definition of similarity degree between two triangular fuzzy numbers. By solving the maximization optimization model, the vector of characteristic weights is objectively derived. A new fusion method is proposed according to the overall similarity degree.
Findings
The results of the experiments show that solving the maximization optimization model improves significantly the objectivity and accuracy of object recognition.
Originality/value
The paper studies the type recognition problem in which the characteristic values of object types and observations of sensors are in the form of triangular fuzzy numbers. By solving the maximization optimization model, the vector of characteristic weights is derived. A new fusion method is proposed. This method improves the objectivity and accuracy of object recognition.
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Shailendra Singh, Mahesh Sarva and Nitin Gupta
The purpose of this paper is to systematically analyze the literature around regulatory compliance and market manipulation in capital markets through the use of bibliometrics and…
Abstract
Purpose
The purpose of this paper is to systematically analyze the literature around regulatory compliance and market manipulation in capital markets through the use of bibliometrics and propose future research directions. Under the domain of capital markets, this theme is a niche area of research where greater academic investigations are required. Most of the research is fragmented and limited to a few conventional aspects only. To address this gap, this study engages in a large-scale systematic literature review approach to collect and analyze the research corpus in the post-2000 era.
Design/methodology/approach
The big data corpus comprising research articles has been extracted from the scientific Scopus database and analyzed using the VoSviewer application. The literature around the subject has been presented using bibliometrics to give useful insights on the most popular research work and articles, top contributing journals, authors, institutions and countries leading to identification of gaps and potential research areas.
Findings
Based on the review, this study concludes that, even in an era of global market integration and disruptive technological advancements, many important aspects of this subject remain significantly underexplored. Over the past two decades, research has lagged behind the evolution of capital market crime and market regulations. Finally, based on the findings, the study suggests important future research directions as well as a few research questions. This includes market manipulation, market regulations and new-age technologies, all of which could be very useful to researchers in this field and generate key inputs for stock market regulators.
Research limitations/implications
The limitation of this research is that it is based on Scopus database so the possibility of omission of some literature cannot be completely ruled out. More advanced machine learning techniques could be applied to decode the finer aspects of the studies undertaken so far.
Practical implications
Increased integration among global markets, fast-paced technological disruptions and complexity of financial crimes in stock markets have put immense pressure on market regulators. As economies and equity markets evolve, good research investigations can aid in a better understanding of market manipulation and regulatory compliance. The proposed research directions will be very useful to researchers in this field as well as generate key inputs for stock market regulators to deal with market misbehavior.
Originality/value
This study has adopted a period-wise broad-based scientific approach to identify some of the most pertinent gaps in the subject and has proposed practical areas of study to strengthen the literature in the said field.
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Murali Jagannathan and Venkata Santosh Kumar Delhi
Judiciary plays a pivotal role in the overall development of a nation's economy and its involvement assures process transparency and impartiality. However, litigation is often…
Abstract
Purpose
Judiciary plays a pivotal role in the overall development of a nation's economy and its involvement assures process transparency and impartiality. However, litigation is often expensive, uncertain and prone to delays. Notwithstanding such inherent challenges associated with litigation, it is observed that parties in construction disputes do resort to litigation. This study attempts to understand the potential paths triggering litigation of contractual disputes in construction. While extant researchers have identified focus areas or factors influencing litigation, the underlying paths connecting these focus areas, leading parties to litigation, is explored in this study.
Design/methodology/approach
Considering the framework of Rachlinski's “framing theory of litigation” and the mixed-methods approach (qualitative and quantitative approaches), this study proposes and validates a model that identifies the paths to litigation of contractual disputes in construction.
Findings
The results of in-depth interviews, followed by validation through structural equation modelling (SEM), reveal four critical paths, namely positional focus (PF) – contract and dispute characteristics (CDC) – decision to litigate (DTL), milieu influence (MI) – CDC – DTL, MI-PF-DTL and CDC-DTL.
Practical implications
The identified paths highlight the areas policymakers can consider while developing policy interventions to mitigate litigation.
Originality/value
Researchers have identified factors causing litigation in construction. However, attempts to examine the existence of multi-factor “paths” on the decision to litigate (DTL) have hitherto received a muted response, so this study focuses on identifying the project-level path(s) leading to the litigation of contractual disputes in construction.