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Article
Publication date: 12 October 2018

Yanyan Pu, Zongchao Yu, Fengqin Wang, Yiyuan Fu, Tao Yan and Honglin Cheng

The purpose of this study is to develop luminescence sensors for the detection of nitroaromatic compounds (NACs) and metal ions to protect human health and prevent…

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244

Abstract

Purpose

The purpose of this study is to develop luminescence sensors for the detection of nitroaromatic compounds (NACs) and metal ions to protect human health and prevent environmental pollution.

Design/methodology/approach

The composition and morphology of Eu-metal-organic frameworks (MOF) (1) were well characterized by powder X-ray diffraction, elemental analyses, Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy and scanning electron microscopy. The emission spectrum displays that 1 has significant characteristic emission bands of Eu(III) ions. The authors further investigated the fluorescence sensing performances of 1 to NACs and metal ions.

Findings

The results show that Eu-MOF (1) exhibits significant fluorescence quenching effect toward p-nitroaniline and Fe3+ ions with good stability and recyclability. This means that 1 can be used as a multifunctional sensing material for the detection of p-nitroaniline and Fe3+ ions.

Originality/value

The authors have successfully synthesized a fluorescence Eu-based sensing material under hydrothermal conditions. In addition, the fluorescence property and sensing performances for detecting NACs and metal ions were studied. The results suggest that 1 has highly selective fluorescence quenching toward p-nitroaniline and Fe3+ ions with not only high sensitivity and selectivity but also excellent stability and recyclability. Furthermore, this study has confirmed that the multifunctional MOF material is very useful in environment pollutants’ detection and monitoring.

Details

Sensor Review, vol. 39 no. 2
Type: Research Article
ISSN: 0260-2288

Keywords

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Article
Publication date: 1 August 2016

Wei Guo, Honglin Liu and Chaoli Lan

Based on core description, gas logging and laboratory analysis, this paper aims to study the controlling effect of the types of shale sedimentary microfacies in coal…

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63

Abstract

Purpose

Based on core description, gas logging and laboratory analysis, this paper aims to study the controlling effect of the types of shale sedimentary microfacies in coal formations over shale reservoirs using the example of Shanxi formation in Northern Ordos Basin.

Design/methodology/approach

According to core observation, the authors selected typical samples of rock types for thin section analysis to determine the micro features and compositions of rocks.

Findings

By using core observation, we found that fine lithology in Shanxi formation included major shale, carbonaceous shale, partially carbonaceous shale, partially silty shale and silty shale with colors of gray, dark gray, black and/or gray. Shanxi Formation shale are deposited in plant-rich and plant-poor swamps, interdistributary depressions of delta plains, interfluvial depressions of meandering rivers as well as microfacies environment of natural levees and the distal crevasse splay.

Originality/value

Currently, the research on the shale gas in Shanxi Formation in the Ordos Basin is still in its infancy. There is yet no research on the fine-grained partition of the sedimentary facies in coal accumulation environment of Shanxi formation and the controlling effect of sedimentary microfacies over shale reservoirs.

Details

World Journal of Engineering, vol. 13 no. 4
Type: Research Article
ISSN: 1708-5284

Keywords

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Article
Publication date: 8 January 2018

Wenyan Zhuo, Honglin Yang and Xu Chen

The purpose of this paper is to build a phase-type risk model with stochastic return on investment and random observation periods to characterize the ruin quantities under…

Abstract

Purpose

The purpose of this paper is to build a phase-type risk model with stochastic return on investment and random observation periods to characterize the ruin quantities under which the insurance company may take effective investment strategies to avoid bankruptcy.

Design/methodology/approach

By the Markov property and Ito’s formula, this paper derives the integro-differential equations in which the interclaim times follow a phase-type distribution. Using the sinc method, this paper obtains the approximate solutions of the expected discounted penalty function. The numerical examples are given to verify the robustness of the proposed sinc method.

Findings

This paper discloses the relationship between the investment strategy and initial surplus level. The insurance company with a high initial surplus level prefers high risk portfolios to earn more profit. Contrarily, the insurance company would invest low risk portfolios to avoid bankruptcy. In addition, this paper shows that a short observation period would bring higher ruin probability.

Originality/value

The risk model is distinct in that a phase-type risk model is constructed with stochastic return on investment and random observation periods. These considerations in the risk model are in sharp contrast to the setting in which the stochastic return on investment is observed continuously. In practice, the insurance company only can periodically observe the surplus level to check the balance of the book. This setting, therefore, is difficult to adopt. This paper develops a sinc method to solve the approximate solutions of the expected discounted penalty function.

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Article
Publication date: 9 August 2013

Li‐Yueh Lee, Sou Veasna and Wann‐Yih Wu

This study aims to examine the significance of transformational leadership and social support for expatriate adjustment and performance. This study also extends relevant…

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4312

Abstract

Purpose

This study aims to examine the significance of transformational leadership and social support for expatriate adjustment and performance. This study also extends relevant literature on expatriate management to examine the relationships among transformational leadership, social support, expatriate adjustment, and expatriate performance through a mechanism taking into account the moderating roles of cultural intelligence and socialization experience.

Design/methodology/approach

The sample was collected from 156 expatriate managers of Taiwanese multinational company (MNC) subsidiaries operating in China. Structural equation modeling (SEM) in AMOS 21 and hierarchical regression in SPSS 19 were used to test eight research hypotheses.

Findings

The SEM results indicated that transformational leadership and social support make significant contributions to expatriate adjustment and performance. The moderating roles of socialization experience and cultural intelligence were also confirmed in this study.

Originality/value

This study extends a theoretical model of transformational leadership and social support to examine expatriate adjustment and performance based on social learning and social exchange theories. Using a specific Chinese context, the current paper highlights the value and necessity of cross‐cultural adjustment for successful expatriation.

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Article
Publication date: 2 February 2021

Ali Alperen Bakır, Resul Atik and Sezer Özerinç

This paper aims to provide an overview of the recent findings of the mechanical properties of parts manufactured by fused deposition modeling (FDM). FDM has become a…

Abstract

Purpose

This paper aims to provide an overview of the recent findings of the mechanical properties of parts manufactured by fused deposition modeling (FDM). FDM has become a widely used technique for the manufacturing of thermoplastic parts. The mechanical performance of these parts under service conditions is difficult to predict due to the large number of process parameters involved. The review summarizes the current knowledge about the process-property relationships for FDM-based three-dimensional printing.

Design/methodology/approach

The review first discusses the effect of material selection, including pure thermoplastics and polymer-matrix composites. Second, process parameters such as nozzle temperature, raster orientation and infill ratio are discussed. Mechanisms that these parameters affect the specimen morphology are explained, and the effect of each parameter on the strength of printed parts are systematically presented.

Findings

Mechanical properties of FDM-produced parts strongly depend on process parameters and are usually lower than injection-molded counterparts. There is a need to understand the effect of each parameter and any synergistic effects involved better.

Practical implications

Through the optimization of process parameters, FDM has the potential to produce parts with strength values matching those produced by conventional methods. Further work in the field will make the FDM process more suitable for the manufacturing of load-bearing components.

Originality/value

This paper presents a critical assessment of the current knowledge about the mechanical properties of FDM-produced parts and suggests future research directions.

Details

Rapid Prototyping Journal, vol. 27 no. 3
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 8 February 2021

Erfan Rezvani Ghomi, Saeideh Kholghi Eshkalak, Sunpreet Singh, Amutha Chinnappan, Seeram Ramakrishna and Roger Narayan

The potential implications of the three-dimensional printing (3DP) technology are growing enormously in the various health-care sectors, including surgical planning…

Abstract

Purpose

The potential implications of the three-dimensional printing (3DP) technology are growing enormously in the various health-care sectors, including surgical planning, manufacturing of patient-specific implants and developing anatomical models. Although a wide range of thermoplastic polymers are available as 3DP feedstock, yet obtaining biocompatible and structurally integrated biomedical devices is still challenging owing to various technical issues.

Design/methodology/approach

Polyether ether ketone (PEEK) is an organic and biocompatible compound material that is recently being used to fabricate complex design geometries and patient-specific implants through 3DP. However, the thermal and rheological features of PEEK make it difficult to process through the 3DP technologies, for instance, fused filament fabrication. The present review paper presents a state-of-the-art literature review of the 3DP of PEEK for potential biomedical applications. In particular, a special emphasis has been given on the existing technical hurdles and possible technological and processing solutions for improving the printability of PEEK.

Findings

The reviewed literature highlighted that there exist numerous scientific and technical means which can be adopted for improving the quality features of the 3D-printed PEEK-based biomedical structures. The discussed technological innovations will help the 3DP system to enhance the layer adhesion strength, structural stability, as well as enable the printing of high-performance thermoplastics.

Originality/value

The content of the present manuscript will motivate young scholars and senior scientists to work in exploring high-performance thermoplastics for 3DP applications.

Details

Rapid Prototyping Journal, vol. 27 no. 3
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 8 July 2021

Ramesh P. and Vinodh S.

Material extrusion (MEX) is a class of additive manufacturing (AM) process based on MEX principle. In the viewpoint of Industry 4.0 and sustainable manufacturing, AM…

Abstract

Purpose

Material extrusion (MEX) is a class of additive manufacturing (AM) process based on MEX principle. In the viewpoint of Industry 4.0 and sustainable manufacturing, AM technologies are gaining importance than conventional manufacturing route (subtractive manufacturing). Because of the ease of use and lesser operation skills, MEX had wide popularity in industry for product and prototype development. This study aims to analyze energy consumption of MEX-based AM process and its influencing factors.

Design/methodology/approach

A group of factors were identified pertaining to MEX-based AM process. In this viewpoint, this study presents the configuration of a structural model using interpretive structural modeling (ISM) to depict dominant factors in MEX-based AM process. A total of 18 influencing factors are identified and ranked using ISM methodology for MEX process. The Impact Matrix Cross-reference Multiplication Applied to a Classification analysis was done to categorize influencing factors into four groups for MEX-based AM process.

Findings

The derivation of structural model would enable AM practitioners to systematically analyze the factors and to derive key factors which enable comprehensive energy modeling and energy assessment studies. Also, it facilitates the development of energy efficient AM system.

Originality/value

The development of structural model for analysis of factors influencing energy consumption of MEX-based AM is the original contribution of the authors.

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